The present study examined the sustained effects of acute resistance exercise on inhibitory function in healthy middle-aged adults. Seventy healthy middle-aged adults (mean age = 46.98 ± 5.70 years) were randomly assigned to exercise or control groups, and the Stroop test was administered before, immediately after, and 40 min after exercise. The resistance exercise protocol involved two sets of seven exercises performed for a maximum of 10 repetitions, with 60 s between sets and exercises. Acute resistance exercise resulted in higher Stroop test performance under the incongruent (inhibition) and interference conditions immediately post-exercise and 40 min post-exercise. Furthermore, the difference in scores after 40 min was significant. The findings indicate that a moderately intensive acute resistance exercise could facilitate Stroop performance and has a more beneficial effect on sustaining of cognition that involves executive control at least 40 min. Cognitive ability is important for daily life as a main component of the health-related quality of life. However, the most impactful change in cognition with increasing age is declining executive function (EF), with cognitive impairments severe enough to impair their everyday functional abilities . EncompaAccording to meta-analyses of exercise and inhibitory control, acute aerobic or resistance exercises have small to moderate effects on inhibitory control in middle-aged populations . NotablyIn reviewing the literature on sustained effects of resistance exercise on inhibitory control, Despite these initial inquiries into the effect of acute exercise on inhibitory aspects of executive control, little research has examined this relationship of the time course to the cognitive benefits. Therefore, a rationale is raised for our current theoretical understanding for the acute exercise intensity-cognition interaction based on the arousal-performance interaction theory. A prominent theoretical framework proposed by The purposes of this study was to examine the immediate and sustained effects of acute resistance exercise on inhibition at 5 and 40 min post-exercise after an acute resistance exercise. A previous meta-analysis reported that the largest effects of exercise on cognitive performance could generally be observed during a period of 11–20 min after exercise . Howevern = 35) or a control group (n = 35) by drawing lots. Detailed characteristics of the participants are presented in A total of 70 community-dwelling healthy adults, aged 40–60 years, were initially recruited in Taipei, Taiwan. The potential participants were included if they met the following criteria: (1) they met the requirements of the physical activity readiness questionnaire (PAR-Q), to ensure their safety when performing a single bout of exercise and (2) they achieved a score of more than 26 on the Chinese version of the mini-mental state examination (MMSE), verifying that they may be considered cognitively normal . The excThe Stroop test was developed by the Vienna Test System. The Vienna test system is a test system for computerized executive function assessments. With it, digital tests of executive function can be administered and it provides automatic and comprehensive scoring. It includes a series of computerized tasks. Perceptual motor speed is measured when reading color words  and naming the color that the word is (or is not) written in. The test uses correct responses on time as reaction time. The test has 128 trials, with 5 trials for practice. Trials present the four types of Stroop task, namely, the baseline of reading words and naming colors as the congruent condition, and reading and naming words under the incongruent condition; the difference in reaction time between the conditions is the interference tendency and is referred to as the Stroop effect. A positive value indicates an increased interference tendency, whereas a negative value is characteristic of a reduced interference tendency. In the congruent condition, the reading word and naming color stimulus is displayed in the color matching the meaning of the word . In the incongruent condition, the reading word stimulus is displayed in a color matching the meaning of a different stimulus . The participants must read the word  aloud and disregard the color of the word is written in . Alternatively, with the naming color stimulus, the participant must state the color of the word  and disregard the word’s meaning . The stimuli for each condition were displayed on a 15-inch laptop screen, and the test length was approximately 8 to 10 min. The validity and reliability of the Stroop test has been extensively reported . The StrA Polar watch  was worn by each participant to measure the participant’s heart rate (HR) during the resistance exercise stage, with the HR data from the HR monitor being recorded at 1-min intervals. HR data were assessed as an indicator of the physiological arousal induced by the resistance exercise. Four HR variables were identified: pre-exercise HR, treatment HR, immediately post-exercise HR, and 40-min post-exercise HR. Pre-exercise HR was determined 60 s before the performance of the first Stroop test (pre-exercise); the treatment HR was the average HR during the moderate intensity or control treatment; and the immediately post-exercise HR and 40-min post-exercise HR were assessed 60 s before the participant performed the Stroop tests for immediately post-exercise and 40 min post-exercise, respectively.Each participant completed the rating of perceived exertion (RPE), which was defined as their perception of their own level of effort during the exercise. According to the original scale by The participants were instructed to avoid engaging in any other resistance exercise training or any other physical activities such as jogging, running, yoga, dance, tennis, or table tennis for a week before the experimental session. The 10-repetition maximum (RM) represents the maximum weight an individual can successfully lift in 10 repetitions and approximates 70% of the 1-RM. After stretching, the participants were asked to warm up with light resistance exercise for 10 min, and were then instructed to change the load and to continue the testing process until they reached a load level that they would be able to lift for a maximum of 10 repetitions. Generally, the instructor was able to adjust the loads such that the 10-RM could be measured within four testing sets. The following seven muscle exercises were selected: the bench press, shoulder press, dumbbell rows, alternating bicep curls, triceps pushdowns, leg extensions, and leg curls . The loaThe participants were requested to visit the Sport Pedagogy Laboratory on two separate testing days at least 48 h apart. Trained laboratory researchers administered questionnaires regarding the inclusion criteria, the 10-RM tests for each of the seven muscle groups, and the Stroop tests. On Day 1, each participant was invited to visit the laboratory at the confirmation stage and was presented with a brief introduction to the experiment. The informed consent form, MMSE, PAR-Q, and medical health history questionnaire were given to them to read and complete. After completing the questionnaires on Day 1, each participant was asked to sit quietly, individually, on a comfortable sofa in a dimly lit room for 15 min and instructed to attach the HR monitor. After the 15-min period, the HR baseline was recorded, and the participant’s 10-RM for each of the muscle groups was determined. The participants were told to avoid the use of stimulants such as caffeine the day before and the day of the tests.On Day 2, each participant was again asked to sit quietly, individually, on a comfortable sofa in a dimly lit room for 15 min. Then, pretest scores for the Stroop test were collected, and the participant was asked to press the correct color button on the keyboard for each stimulus in each condition. In the exercise groups, the participants then warmed up for 10 min and conducted the resistance exercises for 25–30 min. At the start of each session, the participants were fitted with a Polar Cybex 770T’s CardioTouch HR monitor to assess their physiological arousal and the effects of the selected intensities on cardiovascular responses. Subjective RPE was collected after each set of exercises using a category-interval rating scale ranging from 6  to 20 . In the control group, the participants were instructed to sit quietly in a well-lit room and read exercise-related magazines for 30 min.Immediately post-exercise (3 to 5 min after the end of the session), we asked each participant to complete the Stroop test again using the same directions and under the same conditions as the pre-exercise test. Afterward, the participant rested for 30 min and then completed all four conditions of the Stroop test again (40-min post-exercise stage). Each of the participants was given US$20 as compensation for participating in the study and was debriefed by a member of the research team.t-test or a χ2 test to compare demographic data and pre-exercise variables with continuous and discrete scales, respectively, between the groups. The analyses indicated no significant differences between the groups for age , height , weight , BMI , years of education , resting HR , or MMSE score . Furthermore, no differences were observed for sex ratio . Descriptive data are summarized in To ensure homogeneity of potential confounders between the control and exercise groups, an analysis of independent samples was applied using a F = 1027.75, p < 0.0001, partial η2 = 0.99), indicating that the treatment HR was significantly higher than the immediately post-exercise HR and the follow-up HR, which was also significantly higher than the pre-exercise HR. The average RPE value during the resistance exercise was 15.25 ± 1.46. Descriptive data for the exercise manipulation check are summarized in One-way repeated ANOVA was used to analyze HR in the exercise group, and the results revealed a significant time effect  = 16.14 and 13.13, p < 0.0001, partial η2 = 0.33 and 0.28) and significant interactions of Group with Time  = 5.06 and 4.66, p < 0.01, partial η2 = 0.13 and 0.12). However, no significant Group effect was observed  = 0.41 and 0.01, p > 0.05). Follow-up decompositions indicated significant Time effects for the congruent condition of reading words and naming colors in the exercise group  = 13.21 and 11.44, p < 0.001, partial η2 = 0.45 and 0.41), wherein pairwise comparisons revealed that the participants exhibited faster reaction times (RTs) in the immediately and 40-min post-exercise tests than in the pre-exercise test. No RT difference was observed between the two post-exercise tests. As expected, no significant Time effects were observed for the congruent condition of reading words and naming colors in the control group  = 2.96 and 1.92, p > 0.05). The results under the congruent condition are presented in In the congruent condition of reading words and naming colors, the 2 × 3 mixed ANOVA revealed a significant Time effect  = 17.06 and 13.80, p < 0.0001, partial η2 = 0.34 and 0.29) and significant interactions of Group with Time  = 9.67 and 10.88, p < 0.0001, partial η2 = 0.22 and 0.25). The results also indicated a significant Group effect  = 4.22 and 4.22, p < 0.05, partial η2 = 0.06 and 0.06). The exercise group exhibited faster RTs than the control group did in the incongruent condition of reading words and naming colors immediately post-exercise and 40-min post-exercise (t(68) = −3.04, −3.96, −3.02, and −3.07, p < 0.01). Follow-up decompositions indicated significant Time effects for the exercise group under the incongruent condition of reading words and naming colors  = 20.72 and 20.64, p < 0.001, partial 2η = 0.56 and 0.56), wherein pairwise comparisons revealed that the participants again exhibited faster RTs immediately and 40-min post-exercise than at pre-exercise, and no significant difference was noted between the post-exercise scores. As expected, no significant Time effects were observed for the incongruent condition of reading words and naming colors in the control group  = 1.33 and 0.24, p > 0.05). The RTs under the incongruent condition are presented in To test the hypothesis regarding the effects of acute resistance exercise on the incongruent condition of reading words and naming colors, we conducted 2 × 3 mixed ANOVA. The results revealed significant Time effects  = 5.04 and 3.49, p < 0.01, partial 2η = 0.13 and 0.10) and significant interactions of Group with Time under the interference conditions  = 6.36 and 4.01, p < 0.05, partial 2η = 0.11 and 0.11). A significant Group effect was also observed  = 26.07 and 47.19, p < 0.001, partial 2η = 0.27 and 0.41). Notably, the exercise group had shorter RTs than the control group immediately and 40-min post-exercise (t(73) = −5.17, −5.29, −5.04, and −6.07, p < 0.001). Follow-up decompositions indicated significant Time effects for the exercise group  = 13.52 and 6.38, p < 0.01, partial 2η = 0.45 and 0.28), wherein pairwise comparisons revealed that the participants exhibited faster RTs in the post-exercise tests than in the pre-exercise test; no significant RT difference was observed between the two post-exercise tests. As expected, no significant Time effects were observed for the control group  = 1.17 and 0.08, p > 0.05). The results suggested that the responses of the exercise group were quicker both immediately post-exercise and 40-min post-exercise compared with those pre-exercise. They were also significantly quicker than those of the control group. The RTs for the interference tendency are presented in To test the hypothesis regarding the effects of acute resistance exercise on the interference tendency of reading words and naming colors as indicators of inhibitory control, we conducted 2 × 3 mixed ANOVA. The results revealed significant Time effects  that is associated with facilitated inhibitory control performance . AlthougThis study had limitations that warrant caution with respect to the interpretation of its results and future research. Nonetheless, based on the findings of the present study, further research efforts in this field are suggested. First, the outcome of the study may have been affected by the small size and diversity of the sample; however, given the significance and size of the effects, we believe that a larger sample size would not have significantly altered the outcome. Second, an additional limitation of these data is the inability to gain a mechanistic understanding of the effects of acute resistance exercise on inhibitory control. That is, despite the interesting and positive sustained impacts about RT observed herein, little is known regarding which accuracy of interference condition and interference tendency on Stroop Test was influenced by an acute resistance exercise bout. Third, future studies should be designed to further our understanding of the measurement of intra-subject variation  for RTs. Meanwhile, the recording of ERPs could be used to explore stimulus and response conflicts within the processes underlying standard deviation and coefficient of variation for RTs. Whether standard deviation and coefficient of variation for RTs are related to localized brain regions is unknown, and neuroimaging could provide clarification. Because the intra-subject variation in RTs is a measure of a subject’s consistency in responding to the conditions of congruent and incongruent stimuli, often quantified as the standard deviation and coefficient of variation of intra-subject variation across a task period; higher intra-subject variation, reflect in larger standard deviations, is associated with greater variability, or inconsistency, of responses. Finally, resistance exercise training and arousal-induced alterations in lateral prefrontal cortex neural activity , biochemOur findings suggest that moderate-intensity resistance exercise promotes EF in healthy middle-aged adults. In summary, this study has extended the literature by providing evidence that acute resistance exercise has positive, sustained impacts on multiple cognitive functions, as assessed by the Stroop test, in healthy middle-aged adults. Furthermore, the results suggest that moderate-intensity resistance exercises have positive impacts and sustained effects on particular types of EF in middle-aged adults, with those impacts being larger under task conditions that place greater demands on inhibitory control cognition.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the University of Taipei’s Institutional Review Board (IRB-2020-011). The patients/participants provided their written informed consent to participate in this study.C-CC and C-JH contributed to conception and design of the study and wrote sections of the manuscript. M-CH and Y-HC organized the database. W-YW and M-YH performed the statistical analysis. C-CC, M-CH, Y-HC, W-YW, MY-H, and C-JH wrote the first draft of the manuscript. All authors contributed to manuscript revision, read, and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Ongoing hemorrhage from hepatobiliary and pancreatic injuries continues to daunt even the most experienced surgeon. Despite the widespread centralization of elective hepatopancreatobiliary (HPB) surgery to high-volume centers, HPB trauma remains relatively common and requires a rapid and thoughtful approach . Although blood flow within the pancreatic gland is impressive, the dominant source of hemorrhage associated with pancreatic trauma remains the mesenteric venous structures that surround it. More specifically, the superior mesenteric, portal, inferior mesenteric, and splenic veins remain the prime sources. Although the anatomy of the portal and superior mesenteric veins is relatively constant, the insertion point of the inferior mesenteric vein can vary dramatically . It is also generally stated that the portal vein does not possess any branches arising from its anterior surface . As with many dogmatic anatomic comments, this "rule" is frequently broken. The presence of large venous tributaries from the portal vein into the head and uncinate of the pancreas is absolute however. The largest of these are the gastroepiploic trunk and the first jejunal venous branch. Hemorrhage from these structures can be torrential and unforgiving.Although portal venous injuries in the retropancreatic location are notoriously difficult to access, human anatomy has provided us with a powerful temporizing maneuver. More specifically, digital pressure from the front of the gland is often adequate to temporarily control venous hemorrhage via simple compression. In cases where this fails, a rapid Kocher maneuver is required to allow concurrent anterior and posterior digital pressure and therefore occlusion of the portal vein and distal SMV. This maneuver provides the surgeon time to add a second suction device, call for experienced assistance, notify the anesthesiologist for predicted massive blood loss, and have the nursing staff ready all vascular instrumentation and suture selections that the surgeon will require. If the hemorrhage appears to arise from the bottom of the pancreas , it is helpful to rapidly mobilize the right colon to provide improved inferior exposure and eventually control. Inspection of the right lateral small bowel mesentery will also provide insight into possible hemorrhage caudal to the pancreatic head/uncinate. As with most massive bleeding, the importance of an educated assistant who can expose the venous injury (both suctioning of blood and retraction of adjacent organs) cannot be overstated. Excellent help is typically the difference between completing an efficient and smooth repair compared to flailing with massive blood loss and patient demise.If pressure and packing do not persistently control hemorrhage from the retropancreatic portion of the portal vein , then rapid exposure and subsequent ligation/repair of the vessel may be required. This can be achieved by dividing the neck/body of the pancreas gland . This maneuver is discussed significantly more often in the literature than it is actually performed in the real world. It also carries with it a substantial risk of inadvertently enlarging the venous injury . If this maneuver is triggered however, rapidly place 4 retraction sutures (3-0 Prolene on MH needles) through the pancreatic neck in a figure-of-eight manner immediately lateral and medial to the portal vein (at both the top and bottom of the gland). There is significant risk of ligating the hepatic artery at the top, so you must be extremely accurate. This is not the time to flail or lose focus. These 4 sutures will provide significant retraction from both sides of the pancreatic neck, allowing the surgeon to use high-voltage Bovie electrocautery to transect the pancreas quickly (in combination with adequate ongoing suction). Remember that the vein is not typically dissected off of the back of the pancreas , so you need to slow down as you move closer to the posterior margin of the pancreas. Repairs to the portal or superior mesenteric veins themselves are generally performed with a 5-0 or 6-0 RB-1 Prolene .When necessary, venous tributaries from the portal vein can generally be ligated. Even the portal vein itself can be ligated in a damage control scenario. Interestingly, these patients display a superior survival when evaluating the literature as a whole . This likely reflects the varying comfort level among surgeons attempting to address these difficult injuries. Another possible solution is to place a temporary intravascular shunt (TIVS) in continuity for major portal venous injuries. Portal veins are best shunted with a 22F to 26F chest tube, or large nasogastric feeding tube for small women. Once inserted into the vessel (in-line), the TIVS can be locked into place via silk ties or double vessel loops that are tightened/locked with clips. If silk ties are selected , it must be remembered that the vessel itself will need to be trimmed back proximal to the silk to ensure there is no ischemia at the time of the reconstruction. This may become a problem in areas where every bit of vessel length is critical .Ongoing hemorrhage from the splenic vein is much less treacherous. Bleeding to the anatomic left of the portal vein can be solved via a rapid distal pancreatectomy/splenectomy with bulk ligation of the splenic artery and vein. Energy instrumentation and staplers can make this endeavor simple and efficient. More specifically, divide the short gastrics and gastroepiploics, mobilize the transverse and left colon, and finally free the spleen with an energy instrument that works well within pools of blood . A multitude of staplers can then be effectively utilized to divide the pancreatic body concurrent to ligation of the splenic artery and vein. The TX-30v linear stapler (Ethicon) is a workhorse for the elective HPB surgeon and is superb for this indication. Alternatively, in the context of a soft gland, a laparoscopic stapler  can also be used to divide these structures en masse. The dominant risk is mistaking the hepatic artery for the proximal splenic artery and dividing it. A quick test clamp of the splenic artery with a large bulldog clamp  eliminates this potential disaster. Prior to placing either stapler, however, the surgeon must rapidly dissect around the pancreatic body and place a vessel loop or umbilical tape for complete control of the gland. This is often best done with a single well-educated finger. Remember that the retroperitoneum at this location  is generally spared from hemorrhage and easily accessible from the bottom once the transverse colon is mobilized caudally by approximately 1 cm. The splenic vein will remain stuck to the underside of the elevated pancreas, and the splenic artery can be palpated. Although this short series of maneuvers may sound challenging, it becomes much easier when rapidity is in demand. The most extreme damage control maneuver for a splenic venous injury remains bulk ligation with a large suture, followed by packing.Although it is beyond the aims of this article, the dominant postoperative complications surrounding pancreatic  injuries remain leaks from preceding pancreatoduodenal closures and/or anastomoses. Critically injured patients rarely tolerate the physiologic consequences of uncontrolled leaks. Pancreatic juices are also highly dangerous in the context of a fresh vascular repair, anastomosis, or TIVS. As a result, generous closed suction drainage must be considered to control any potential pancreatic leaks after the ongoing hemorrhage has been stopped.The dominant challenge with hepatic trauma generally surrounds the management of the hemodynamically unstable patient with a bleeding, high-grade liver injury. More specifically, these injuries can be difficult to expose, temporize, and/or repair for any surgeon who does not make his or her living in this region of the upper abdomen. These patients often present in physiologic extremis and therefore require damage control resuscitation techniques. Early recognition of their critical condition, as well as immediate hemorrhage control, is essential. Unlike the spleen and kidney, the liver cannot generally be resected in a rapid on-demand basis. Regardless of your training, these injuries will engage all of your senses, test your technical skills, require the utmost focus, and demand great teamwork from you and your colleagues.Patients with major injury as a result of either blunt or right upper quadrant penetrating trauma must undergo an immediate Extended Focused Assessment with Sonography for Trauma examination in the trauma bay to confirm the presence of large-volume intraperitoneal fluid. This examination is repeatable and should be used to reevaluate patients in urban centers who present immediately following their injuries. Massive transfusion protocols as part of a damage control resuscitation must be initiated early during the patient assessment process. If the patient rapidly stabilizes their hemodynamics, they should undergo an emergency computed tomography (CT) scan of their torso. If they remain clinically unstable, they must be transferred to the operating theater without delay. Hemorrhage control is the dominant driver limiting survival. Collateral issues such as optimal intravenous access, imaging of other areas , and fracture fixation are secondary problems.Thankfully, not all patients with liver injuries are actively dying secondary to hemorrhage. More specifically, in hemodynamically stable patients without CT evidence of a hepatic arterial blush, admission and close observation are warranted. In hemodynamically stable patients with a hepatic arterial blush, immediate transfer to the interventional angiography suite (or hybrid operating room) is recommended. Hepatic angiography and/or portography with selective embolization is indicated with either autologous clot or absorbable embolization medium. In persistently hemodynamically unstable patients, however, an immediate laparotomy is essential. More to the point, early recognition of a patient with ongoing hepatic hemorrhage and immediate transfer to the operating theater are crucial. Delays will lead to the loss of life.The patient should be rapidly prepared and draped with available access from the neck to the knees. Vascular instruments and balloons must be open and at the ready. A midline laparotomy from xiphoid process to pubic bone should be performed with 3 passes of a sharp scalpel. The peritoneal cavity should be packed in its entirety with laparotomy sponges for patients with blunt liver injuries. Although the ligamentum teres can be ligated, the falciform ligament may be left intact . This offers a medial wall against which to improve packing pressure. The right upper quadrant should be evaluated prior to any potential intraperitoneal packing for penetrating injuries. If hemorrhage continues, an early Pringle maneuver (clamping of the porta hepatis with a vascular clamp) is recommended. This is both diagnostic and potentially therapeutic. If bleeding continues despite application of a Pringle clamp, a retrohepatic inferior vena cava (IVC) or hepatic venous injury is likely (assuming that a replaced left hepatic artery is not the source of inflow occlusion failure). Critically injured patients in physiologic extremis do not tolerate extended Pringle maneuvers to the same extent as patients with hepatic tumors undergoing elective hepatic resection. Forty minutes represents the upper limit of viable. If the liver hemorrhage responds to packing but continues to hemorrhage when unpacking is completed, they should be repacked and transferred to the ICU with an open abdomen once damage control of concurrent injuries is complete. Cover the liver with a plastic layer of sterile x-ray cassette material to avoid capsular trauma upon eventual unpacking. It should be reemphasized that all damage control procedures should be completed in less than 1 hour. Return to the operating suite in patients with packed abdomens should occur in 48–72 hours .If the liver hemorrhage control is dependent on maintenance of a Pringle maneuver despite packing, call for senior assistance, mobilize the right lobe, and suture the IVC or hepatic veins with 4-0 Prolene on SH needles. These patients may also require total vascular exclusion/occlusion (TVE) of the liver. This technique involves complete occlusion of the infrahepatic IVC, suprahepatic IVC, porta hepatis (Pringle maneuver), as well as an aortic cross-clamp within the abdomen. If TVE is pursued without concurrent clamping of the aorta, the patient will often arrest due to a lack of coronary perfusion. Prior to performing TVE of the liver, it is imperative to allow the anesthetic team to resuscitate the patient to the best of their ability to facilitate IVC clamping. We prefer to obtain suprahepatic IVC control within the abdomen in patients with a normal length of IVC inferior to the diaphragm. An alternate approach involves accessing the IVC immediately prior to its entry into the heart . This 2-cm length of IVC is easily accessible by opening the pericardial sac following division of the central tendon of the diaphragm. Alternatively, it can also be accessed from the thorax if a thoracotomy has already been performed. Control of the infrahepatic IVC can be rapidly gained by opening the overlying peritoneum and bluntly encircling the IVC cephalad to the right real vein .Veno-veno bypass is also a theoretical option in some very specific scenarios but is rarely required if the patient can be adequately resuscitated to allow for IVC clamping. Furthermore, a lack of transplantation training in most trauma/general surgeons precludes expeditious use of this bypass.In the case of central hepatic gunshot wounds or deep central lacerations where access and exposure are difficult, ongoing hemorrhage should be stopped with balloon occlusion. Either a Blakemore esophageal balloon or variant (red rubber catheter with overlying Penrose drain and 2 silk occlusion ties) is exceptional at stopping ongoing bleeding at the bottom of deep central hepatic injury tracts (including retrohepatic IVC injuries). Foley catheters of varying sizes are also helpful. These should be deflated approximately 72 hours after the initial placement. If hemorrhage continues, they should be reinflated and left in vivo for 3 additional days.Another excellent damage control option for major IVC disruption, portal vein injuries, and combined portal venous/hepatic arterial trauma is the use of a TIVS. Although a large variety of tubes can be utilized as a TIVS , they do not need to be heparin bonded. More specifically, TIVS typically fails for 1 of 3 reasons: (1) selection of a tube that is too small for the caliber of the disrupted vessel, (2) kinking of the tube itself, and (3) inadequate concurrent outflow . IVC injuries in adults are usually best approximated with a 32F to 36F chest tube. Portal veins are best shunted with a 22F to 26F chest tube, or large nasogastric feeding tube for small women. Hepatic arteries are best served by inserting pediatric nasograstric or feeding tubes. These TIVS may be locked into place with either silk ties or double-looped vessel loops and locking clips. As previously mentioned, the surgeon should consider the latter method in scenarios where maximizing the vessel distance is critical because the vessel will need to be further trimmed back beyond the silk ties when reconstruction is eventually attempted.Vascular reconstruction following insertion of a TIVS should ideally involve an experienced HPB surgeon. The timing of this reconstruction will depend entirely upon the physiological and biochemical recovery of the patient. As soon as this is achieved in the critical care suite, the patient should return to the operating theater for repair. The surgeon must also ensure that a wide range of potential conduits is available and ready . One superb conduit choice for IVC reconstruction following TIVS removal is bovine pericardium (or biologic mesh) that is fashioned into a tube of the appropriate size . This conduit performs quite well in leaking/infected traumatic fields.Although TIVS has revolutionized damage control trauma scenarios, the traditional damage control option for vascular trauma of ligation remains relevant. It is clear based on a literature review of portal venous and superior mesenteric venous trauma that ligation of this vessel, rather than reconstruction, is often superior. This observation is likely multifactorial but almost certainly relates to surgeon unfamiliarity  with these vessels in anatomically hostile regions. Similarly, ligation of the IVC is also well recognized as a successful damage control maneuver. If the IVC is ligated, wrapping a patient's legs with compression garments, elevation of patient's lower extremities above the heart, and judicious fluid management for 5 postoperative days are critical.Although unusual, patients with penetrating injuries to the hepatic artery will present as critically ill and may require ligation . Portal vein injuries should ideally be repaired with 5-0 or 6-0 Prolene once control is obtained. Clamps above and below the injury are essential for visualization. Alternate damage control options include TIVS with a small chest tube conduit or ligation (assuming the hepatic artery is intact).If an atrial–caval shunt is contemplated, 2 experienced surgical teams (1 for the chest and 1 for the abdomen) are essential to ensure both rapidity and efficiency. The decision to pursue this shunt must be made early in the exploration process. Unfortunately, these shunts rarely result in patient salvage in even the most experienced trauma centers. If a center and/or surgical team considers this maneuver to be part of their armamentarium for treating ongoing hemorrhage from retrohepatic injuries, a prestocked kit with all the necessary items must be readily available. Similar to utilizing TIVS and occlusion balloons, demanding these instruments in the wee hours of the morning among a stressed clinical team for a decompensating patient is likely to fail. Remember that Allis clamps are also excellent for the initial control of most venous hemorrhage.In conclusion, massive ongoing hemorrhage associated with pancreatic trauma is typically compressible with a well-educated hand/finger. A detailed knowledge of anatomy and a talented assistant will make the difference between a huge save and a long presentation at morbidity and mortality conference.Although the published history of hepatic trauma is littered with descriptions of technical maneuvers ordered in a hierarchical scheme, very few are relevant in the context of modern trauma care. Packing of hepatic hemorrhage controls the vast majority of ongoing bleeding in critically ill patients. Selective use of vessel ligation, parenchyma resection, and hepatic transplant remain less common strategies. Ongoing hemorrhage from major hepatic injuries remains the most challenging of all intraperitoneal injuries due to issues with exposure, blood flow, and difficult technical repairs. Initiate damage control resuscitation and massive transfusion protocols early in your assessment. Rapid completion of damage control procedures is essential (< 1 hour). Flailing and indecision lead to prolonged operative times and patient demise. If diagnosis and therapy are rapid, patients who present in physiologic extremis as a result of major hepatic hemorrhage have a good chance of survival in the context of a prolonged hospital stay. Elective liver surgeons can be of superb assistance when available.Dr. Ball wrote and edited all components of this manuscript.Dr. Ball has no conflicts of interest to declare.There was no funding for this article.No patient data were included in this manuscript. No ethics approval was obtained.


Some studies have revealed a close relationship between metabolism-related genes and the prognosis of bladder cancer. However, the relationship between metabolism-related long non-coding RNAs (lncRNA) regulating the expression of genetic material and bladder cancer is still blank. From this, we developed and validated a prognostic model based on metabolism-associated lncRNA to analyze the prognosis of bladder cancer.Gene expression, lncRNA sequencing data, and related clinical information were extracted from The Cancer Genome Atlas (TCGA). And we downloaded metabolism-related gene sets from the human metabolism database. Differential expression analysis is used to screen differentially expressed metabolism-related genes and lncRNAs between tumors and paracancer tissues. We then obtained metabolism-related lncRNAs associated with prognosis by correlational analyses, univariate Cox analysis, and logistic least absolute shrinkage and selection operator (LASSO) regression. A risk scoring model is constructed based on the regression coefficient corresponding to lncRNA calculated by multivariate Cox analysis. According to the median risk score, patients were divided into a high-risk group and a low-risk group. Then, we developed and evaluated a nomogram including risk scores and Clinical baseline data to predict the prognosis. Furthermore, we performed gene-set enrichment analysis (GSEA) to explore the role of these metabolism-related lncRNAs in the prognosis of bladder cancer.By analyzing the extracted data, our research screened out 12 metabolism-related lncRNAs. There are significant differences in survival between high and low-risk groups divided by the median risk scoring model, and the low-risk group has a more favorable prognosis than the high-risk group. Univariate and multivariate Cox regression analysis showed that the risk score was closely related to the prognosis of bladder cancer. Then we established a nomogram based on multivariate analysis. After evaluation, the modified model has good predictive efficiency and clinical application value. Furthermore, the GSEA showed that these lncRNAs affected bladder cancer prognosis through multiple links.A predictive model was established and validated based on 12 metabolism-related lncRNAs and clinical information, and we found these lncRNA affected bladder cancer prognosis through multiple links. Bladder cancer, as a common tumor of the urinary system, has always been the focus of research. Recent studies have shown that the metabolism of glycogen, lipid, amino acid, and other substances is closely related to the diagnosis and prognosis of tumors , 2. For The lncRNAs play a crucial role in transcriptional regulation, epigenetic gene regulation, and disease, a kind of non-coding RNAs greater than 200 nucleotides, with no protein-coding function , 11. WitFor bladder cancer, immune-associated and autophagy-associated lncRNAs were found as a marker of early diagnostic and prognostic treatment –20. ReceAlthough we know the nonnegligible fact that metabolism-related genes and lncRNAs are involved in tumor prognosis. At present, the research on metabolism-related lncRNA is not abundant, which is the starting point of this dissertation. It is of great underlying value to study metabolism-related lncRNA to accurately predict the prognosis of bladder cancer. Hence, to address the clinical values, we tried to establish a nomogram containing metabolism-related lncRNAs and clinical data and explore the possible functions of metabolism-related lncRNAs beings through the GSEA.https://portal.gdc.cancer.gov). And metabolism-related gene sets were downloaded from the GSEA database (https://www.gsea-msigdb.org/gsea/index.jsp). Taking | log2FC | > 0.5 and P < 0.05 as standards, the “edgeR” package was used to construct the volcano map and distinguish the differentially expressed metabolism-related gene and lncRNAs in tumors and paracancer tissues. The correlation between metabolism-related genes and lncRNAs is measured by the Pearson correlation coefficient. Metabolism-related gene and lncRNAs whose correlation coefficients satisfy | R2 | > 0.5 and P < 0.05 are considered related and used for further analysis.The RNA-Seq, lncRNA sequencing data, and related clinical information of bladder cancer were extracted from TCGA , calibration plot, and decision curve analysis (DCA).The differentially expressed metabolism-related genes in the high-risk group and low-risk groups were analyzed for gene enrichment. To explore what biological functions or pathways these expressed different genes might be involved in.http://www.R-project.org). And P < 0.05 was considered statistically significant.All statistical computations were conducted using the R software, version 4.0.2  and validation group (131). In the training group, the risk score model was determined by multivariate cox regression analysis to calculate the coefficients for selected lncRNAs.P < 0.05). And in both the training group and validation group, the AUC was greater than 0.71  functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis in differentially expressed metabolism-related genes between high and low-risk groups. Then we presented 9 KEGG molecular pathways in which different genes were enriched Worldwide, bladder cancer is characterized by high incidence, poor prognosis, and high economic burden. How to accurately predict prognosis and explore new therapeutic targets are urgently needed in the clinic. Previous studies have found metabolism-related genes and lncRNAs affect the prognosis of bladder cancer in different aspects , 23. HowAlthough there are few studies on the prognostic relationship between metabolism-related related lncRNAs and bladder cancer, the prediction model based on other types of lncRNAs has a good performance in predicting the prognosis of bladder cancer. In tumor immunity, an 8 immune-related LncRNA classifier for prognostic prediction, could predict prognosis and immunotherapeutic response . And patFrom the Kaplan-Meier survival curve we drew according to subgroups, we could see that this model still has good predictive performance in most subgroups age > 65, female, male, T1-2, T3-4, N0, and M0. In the remaining three subgroups, no significant differences were observed, and the insufficient sample size was considered as the main reason.Our study developed a risk score model with good reliability. This reconfirmed that these selected metabolism-related lncRNA  are dysregulated in bladder cancer.LncRNA DUXAP8 was located on chromosome 20q11 with 2307 bp in length8 . DUXAP8 We found through GSEA that different metabolism-related pathways were significantly enriched both in high and low-risk groups. The galactose metabolism and amino sugar and nucleotide sugar metabolism enrich in patients with high-risk scores, which might mean a poor prognosis in these patients. Consistent with our research, Overexpression of the galactose transporter and galactose binding lectin, may contribute to tumor progression , 42. On We were the first to build a nomogram based on metabolism-related lncRNA. After verification and evaluation, the model can accurately predict the prognosis of bladder cancer. Using GSEA, we initial research the potential function of 12 metabolism-related lncRNA. Admittedly, there are also some limitations to our study. First, further experiments on cells and animals are needed to verify the function of this lncRNA. Second, contained clinical data lacks some important data, such as comorbidities, therapies, smoking, and the cause of death.We identified 12 metabolism-related lncRNAs associated with the prognosis of bladder cancer. And we found these lncRNA affecting bladder cancer prognosis through multiple links could be the focus of future research. From this, the first nomogram was established and validated based on metabolism-related lncRNAs and clinical information.The original contributions presented in the study are included in the article/JTH, JLH, and JK conceived and designed the study, participated in the collection of data and data analysis, and drafted the manuscript. CL and ZS assisted in the design of this research and project development. HY, JL, WX, and HS analyzed the data and reviewed the article. All authors contributed to the article and approved the submitted version.This study was supported by the Science and Technology Planning Project of Guangdong Province (Grant No. 2020A1515111119) and Guangdong Provincial Clinical Research Center for Urological Diseases (Grant No.2020B1111170006). The funders played no role in design of the study, collection, analysis, and interpretation of data or in writing the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Many studies have shown that metabolism-related lncRNAs may play an important role in the pathogenesis of colon cancer. In this study, a prognostic model for colon cancer patients was constructed based on metabolism-related lncRNAs.Both transcriptome data and clinical data of colon cancer patients were downloaded from the TCGA database, and metabolism-related genes were downloaded from the GSEA database. Through differential expression analysis and Pearson correlation analysis, long non-coding RNAs (lncRNAs) related to colon cancer metabolism were obtained. CRC patients were divided into training set and verification set at the ratio of 2:1. Based on the training set, univariate Cox regression analysis was utilized to determine the prognostic differential expression of metabolic-related lncRNAs. The Optimal lncRNAs were obtain by Lasso regression analysis, and a risk model was built to predict the prognosis of CRC patients. Meanwhile, patients were divided into high-risk and low-risk groups and a survival curve was drawn accordingly to determine whether the survival rate differs between the two groups. At the same time, subgroup analysis evaluated the predictive performance of the model. We combined clinical indicators with independent prognostic significance and risk scores to construct a nomogram. C index and the calibration curve, DCA clinical decision curve and ROC curve were obtained as well. The above results were all verified using the validation set. Finally, based on the CIBERSORT analysis method, the correlation between lncRNAs and 22 tumor-infiltrated lymphocytes was explored.By difference analysis, 2491 differential lncRNAs were obtained, of which 226 were metabolic-related lncRNAs. Based on Cox regression analysis and Lasso results, a multi-factor prognostic risk prediction model with 13 lncRNAs was constructed. Survival curve results suggested that patients with high scores and have a poorer prognosis than patients with low scores (P<0.05). The area under the ROC curve (AUC) for the 3-year survival and 5-year survival were 0.768 and 0.735, respectively. Cox regression analysis showed that age, distant metastasis and risk scores can be used as independent prognostic factors. Then, a nomogram including age, distant metastasis and risk scores was built. The C index was 0.743, and the ROC curve was drawn to obtain the AUC of the 3-year survival and the 5-year survival, which were 0.802 and 0.832, respectively. The above results indicated that the nomogram has a good predictive effect. Enrichment analysis of KEGG pathway revealed that differential lncRNAs may be related to chemokines, amino acid and sugar metabolism, NOD-like receptor and Toll-like receptor activation as well as other pathways. Finally, the analysis results based on the CIBERSORT algorithm showed that the lncRNAs used to construct the model had a strong polarized correlation with B cells, CD8+T cells and M0 macrophages.13 metabolic-related lncRNAs affecting the prognosis of CRC were screened by bioinformatics methods, and a prognostic risk model was constructed, laying a solid foundation for the research of metabolic-related lncRNAs in CRC. Clorectal cancer (CRC) is one of the most common gastrointestinal malignancies in the world, whose morbidity and mortality are increasing year by year. In 2018, China’s CRC accounted for the third in the national incidence of malignant tumors and the second in mortality, and the number of new cases and deaths was as high as 376,000 and 191,000, respectively  database and the Gene Set Enrichment Analysis database , respectively.The colon cancer-related data and metabolism-related data in this study were from the Cancer Genome Atlas (TCGA)  between lncRNAs and metabolism-related genes. The lncRNAs with R2>0.5 and p<0.05 were defined as metabolic-related lncRNAs.The colon cancer patients were divided into the training set and validation set at the ratio of 2:1. Based on the training set, the single-factor Cox regression analysis of the metabolic-related lncRNAs was performed to obtain the lncRNAs related to the overall survival. P<0.05 was considered as statistically significant and was included in the LASSO regression analysis to determine the closely related lncRNAs. Multi-factor Cox regression generated risk coefficients and a risk regression model was then constructed. The risk scores of different patients were calculated. The prognostic risk score formula was constructed as follows: Risk score The survival package in R was applied for the subgroup analysis of lncRNAs risk model combined with the clinical subgroup characteristics of patients, such as age, gender, TNM staging. The ability of the risk model to distinguish high and low risk patients in different subgroups was clarified.Univariate and multivariate Cox regression analysis were used to analyze risk scores and clinical factors including age, gender, tumor stage and TNM stage and screened independent prognostic factors. We built a nomogram based on the results of multivariate Cox regression including risk scores. The 3-year and 5-year OS for each patient were predicted based on the nomogram. At the same time, the C index, calibration curve and ROC curve were generated to evaluate the prediction effect of the model. The above results are all verified in the validation set to verify the stability of the results.KEGG analysis was performed on the selected metabolic-related prognostic lncRNAs based on the clusterProfiler package in R using GSEA software to identify genes with rich function and classify gene clusters (P<0.05).CIBERSORT is a tool for deconvolving the expression matrix of human immune cell subtypes based on the principle of linear support vector regression. The CIBERSORT analysis method , 11 was A total of 12 pairs of CRC tissues and noncancerous adjacent tissues were collected from patients who had undergone surgical resection at the Second Hospital of Hebei Medical University . All patients had signed informed consent. This study was approved by the Ethical Review Committee of the Second Hospital of Hebei Medical University and was conducted in accordance with accepted ethical guidelines.Total tissue RNA was extracted using Trizol reagent  following the manufacturer’s protocols. Then, RNA samples were reverse transcribed by Hiscript III Reverse Transcriptase kit  and corresponding RNA expression was evaluated by qRT-PCR with ChamQ™ Universal SYBR qPCR Master Mix kit . GAPDH acted as the internal reference for normalization.The analysis in this study was completed by R software version 3.6.2, in which the limma package was used for differential gene acquisition, cluster Profiler and org.Hs.eg.db package were used for functional enrichment analysis, and survival package was used to perform Kaplan-Meie survival analysis.The expression data of 473 colon cancer tissues and 41 normal colon tissues was downloaded from the TGCA database, and the metabolism-related genes were obtained from the FerrDb database. A total of 279 differentially expressed metabolism-related genes were obtained, of which 151 genes were down-regulated and 128 genes were up-regulated . The heat map showed the expression levels of 13 lncRNAs between the high-risk group and the low-risk group . However, there was no statistical difference in OS between the high-risk and low-risk groups in the N0, M1, and stage I-II-subgroups  .The Nomogram was constructed based on independent prognostic factors determined by the multivariate Cox regression results, such as age, M, and risk score (The KEGG pathway enrichment analysis of the differentially expressed metabolic-related lncRNAs showed that differential lncRNAs were mainly related to the following pathways: chemokine pathways, amino acid and sugar metabolism, NOD-like receptors and Toll-like receptor activation (The CIBERSORT-based analysis method clarified the infiltration level of 22 immune cells in colon cancer patients, and the results showed that lncRNAs used to construct the model had a strong correlation with the polarization of B cells, CD8+ T cells and M0 macrophages (The expression levels of selected metabolic-related lncRNAs were further evaluated and validated in tissues. As illustrated in How to predict the prognosis of colon cancer is an urgent problem for gastrointestinal surgeons. With the development of clinical diagnosis and treatment, some prognostic factors have been discovered, including tumor size, tumor grade and stage. High-throughput biological technology has been widely used to predict cancer recurrence and tumor metastasis by detecting lncRNA or gene changes. In recent years, many studies have shown that changes in the expression patterns of metabolism-related genes are closely related to the occurrence and prognosis of colon cancer [13]. In-depth study of metabolism-related lncRNAs is expected to provide guidance for clinical decision-making.Colon cancer is a common malignant tumor in the digestive system, which seriously affects patients’ survival , 13. HowThis study identified 13 metabolic lncRNAs related to the prognosis of CRC patients through bioinformatics methods, namely LINC01703, LINC01559, AC083880.1, AC027796.4, AL139384.1, LINC00858, LINC01876, AC008760.1, AC006329.1 AL590483.1, AC073283.1, CASC9, AP001469.3, CAPN10-DT, ZKSCAN2-DT, AP006621.4, AC074117.1, LINC01133, AL161729.4 and AC010973.2, thereby building a risk model for predicting prognosis. Combined with clinicopathological analysis, this model can be used as an independent predictor for the prognosis of lung cancer.Among them, LINC01703 has been reported to be of great significance in the diagnosis of lung adenocarcinoma. Wang et al. found that LINC01703 enhanced the invasiveness of NSCLC cells by changing miR-605-3p/MACC1 . In addiPathway enrichment analysis revealed that metabolism-related lncRNAs were mainly related to pathways such as chemokine pathways, metabolic collaterals, NOD-like receptors and Toll-like receptor activation. Liu et al.  found thA large number of studies have shown that there is a significant correlation between tumor cell metabolism and immune cell infiltration in tumor tissues –35. In oin vitro and in vivo studies to clarify the role and specific mechanisms of metabolism-related lncRNAs in the occurrence and development of colon cancer.The relationship between metabolic-related lncRNAs and the prognosis of CRC was preliminarily explored through bioinformatics methods, a model based on 13 metabolic-related lncRNAs was established to predict the prognosis of CRC, and the stability of the model in multiple data sets was fully verified. It provided a new direction for the study of metabolism and colon cancer. We still need further The original contributions presented in the study are included in the article/XZ designed the experiments. CL performed the analysis. CL and QL analyzed the TCGA data. CL, YS and WW wrote and reviewed the manuscript. All authors contributed to the article and approved the submitted version.We would like to acknowledge TCGA for free use.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Vigna unguiculata L.) is particularly sensitive to waterlogging stress during the reproductive stage, with a consequent decline in pod formation and yield. However, little is known about the critical processes underlying cowpea’s responses to waterlogging during the reproductive stage. Thus, we investigated the key parameters influencing carbon fixation, including stomatal conductance (gs), intercellular CO2 concentration, chlorophyll content, and chlorophyll fluorescence, of two cowpea genotypes with contrasting waterlogging tolerance. These closely related genotypes have starkly contrasting responses to waterlogging during and after 7 days of waterlogging stress (DOW). In the intolerant genotype (‘EpicSelect.4’), waterlogging resulted in a gradual loss of pigment and decreased photosynthetic capacity as a consequent decline in shoot biomass. On the other hand, the waterlogging-tolerant genotype (‘UCR 369’) maintained CO2 assimilation rate (A), stomatal conductance (gs), biomass, and chlorophyll content until 5 DOW. Moreover, there was a highly specific downregulation of the mesophyll conductance (gm), maximum rate of Rubisco (Vcmax), and photosynthetic electron transport rate (Jmax) as non-stomatal limiting factors decreasing A in EpicSelect.4. Exposure of EpicSelect.4 to 2 DOW resulted in the loss of PSII photochemistry by downregulating the PSII quantum yield (Fv/Fm), photochemical efficiency (ΦPSII), and photochemical quenching (qP). In contrast, we found no substantial change in the photosynthesis and chlorophyll fluorescence of UCR 369 in the first 5 DOW. Instead, UCR 369 maintained biomass accumulation, chlorophyll content, and Rubisco activity, enabling the genotype to maintain nutrient absorption and photosynthesis during the early period of waterlogging. However, compared to the control, both cowpea genotypes could not fully recover their photosynthetic capacity after 7 DOW, with a more significant decline in EpicSelect.4. Overall, our findings suggest that the tolerant UCR 369 genotype maintains higher photosynthesis under waterlogging stress attributable to higher photochemical efficiency, Rubisco activity, and less stomatal restriction. After recovery, the incomplete recovery of A can be attributed to the reduced gs caused by severe waterlogging damage in both genotypes. Thus, promoting the rapid recovery of stomata from waterlogging stress may be crucial for the complete restoration of carbon fixation in cowpeas during the reproductive stage.Waterlogging is an important environmental stress limiting the productivity of crops worldwide. Cowpea ( Waterlogging stress limits crop yields in about 16% of global cultivated areas, and the problem is exacerbated in poorly drained soils . For exa4 times relative to air [3−, SO2−, Mn4+, and Fe3+ [2 concentrations in the plant root zone and a decrease in hydraulic conductance, resulting in the rapid closure of stomata [Waterlogging first depletes oxygen levels in the soil by rapidly causing the diffusion rate of gases to drop by more than 10e to air . Conseque to air , followeand Fe3+ . Under oand Fe3+ . In addi stomata . Collect stomata , enzymat stomata , plant g stomata , and ultA) of cowpea declined rapidly [A under waterlogging conditions could lead to a decline in plant energy reserves, indicating the existence of a common metabolic pattern. Imperatively, the factors affecting the A of plants are primarily divided into two distinct metabolisms: stomatal and non-stomatal limitations. Due to limited oxygen under waterlogging conditions, plants close their stomata to maintain plant water status, causing a decline in stomatal conductance (gs) and inhibiting the exchange of CO2 required by the plant’s basic processes [s eventually leads to a corresponding decrease in A due to the decreased intercellular CO2 concentration (Ci) under waterlogged conditions [A in the submerged condition is the alteration in mesophyll conductance (gm), which is the diffusion of CO2 from intracellular space to the carboxylation site in the chloroplast stroma [A under waterlogging in legumes is associated with the maximum rate of Rubisco carboxylation (Vcmax), ribulose-1,5-bisphosphate (RuBP) regeneration capacity mediated by maximum electron transport rate (Jmax), photosystem II (PSII) activity, Rubisco activity, and loss of pigments related to leaf senescence [A varies with crop genotype, duration, and severity of waterlogging stress, ranging from a significant decline in sensitive genotypes to little or no inhibition in tolerant genotypes [An important characteristic of plant responses to waterlogging is the alterations in shoot physiology, especially photosynthesis . Previou rapidly . Thus, erocesses . Consequnditions . Anothert stroma . Non-stonescence ,23,24. Tenotypes ,26. Howes in response to waterlogging may enhance the sensitivity of the photosynthetic apparatus to high irradiance, leading to photodamage of PSII due to overproduction of reactive oxygen species (ROS) [v/Fm) of PSII, actual photochemical efficiency of PSII (ΦPSII), and photochemical quenching (qP) of mungbeans were downregulated, whereas the non-photochemical quenching (NPQ) was significantly increased. Conversely, for common bean cultivars with different waterlogging tolerances, Fv/Fm was not affected by waterlogging, while the NPQ of susceptible cultivars increased with the duration of waterlogging treatments [Furthermore, decreased ges (ROS) . The phoes (ROS) . Chloropes (ROS) . Under wes (ROS)  found theatments . Thus, tOf the leguminous crops, cowpea is the most sensitive to waterlogging . Most cos and transpiration rate; E) and non-stomatal  factors. The objectives of this study were to investigate the relative responses of stomatal and non-stomatal factors affecting carbon fixation in cowpea genotypes during waterlogging and recovery period. We hypothesized that cowpea’s growth and physiological responses during and after waterlogging might differ with respect to waterlogging tolerance. This hypothesis was tested in two contrasting cowpea genotypes exposed to a 7-day waterlogging and recovery at the R2 stage using stomatal  and 7 days of recovery (DOR) at the R2 growth stages. Generally, 7 DOW caused a reduction in plant growth of both genotypes. RWC was measured to determine leaf water loss in cowpea genotypes during and after the waterlogging period. At 3 DOW, the mean RWC of waterlogged UCR 369 was statistically at par with the control . HoweverMoreover, waterlogged ‘EpicSelect.4’ showed a drastic reduction in SPAD values after 2 DOW, indicating early leaf senescence F, and mos) until 6 DOW, while the gs of EpicSelect.4 significantly declined by 41% at 1 DOW  under control treatments  is critical for evaluating the PSII photochemical efficiency in stressed plants [v/Fm reflects the PSII’s internal light energy conversion efficiency or maximum light [v/Fm following 7 DOW showed the maximum quantum yield decreased over time but in a genotype-dependent manner  during 7 DOW and 7 DOR became more oxidized in waterlogged EpicSelect.4 from 2 DOW to the end of the experiment compared to the control plants , they generate a pH gradient across the thylakoid resulting in the alterations of NPQ , which rPSII, ΦNPQ, and ΦNO, which sum to one [PSΙΙ of cowpeas, with the extent of decline dependent on cowpea genotypes and the duration of treatments  of cowpeas with the gas exchange parameters. SPAD was positively correlated with most photosynthetic and chlorophyll fluorescence traits, indicating that increased stay-green leaf was associated with the higher photosynthetic performance of cowpea genotypes under waterlogging. Similarly, most photosynthetic traits  under waterlogging treatments were significantly and positively correlated with Fv/Fm, qP, ETR, ΦCO2, and ΦPSII, but negatively associated with NPQ, ΦNO, ΦNPQ, and 1-qL. However, the correlation coefficients of Ci with most parameters were in the range considered moderate to weak. Thus, suggesting Ci acts as a non-stomatal factor affecting the photosynthetic efficiency of cowpeas under waterlogging.Evaluated gas exchange and chlorophyll fluorescence parameters were highly correlated in Pearson’s correlation analysis . Except Waterlogging is a type of abiotic stress that can affect plant growth and development . Our preWaterlogging significantly affects cowpeas’ shoot biomass but depends on growth stages and genotype. Relative to the response of cowpeas and related crops in previous studies, waterlogged-induced reductions recorded in the current study were lower. Most of these evaluations were done at the vegetative stage with over 50% biomass reduction ,31,41. IA was maintained in UCR 369 by sustaining E up to 5 DOW, while the A and E were drastically reduced in EpicSelect.4 under 2 DOW. It is also imperative to note that UCR 369 does not achieve waterlogging tolerance via water conservation. Instead, it was better able to maintain plant water status compared to EpicSelect.4 under waterlogging. This difference was more pronounced in the gas exchange response after 5 DOW  after 7 DOW and suggested that higher Ci limits Rubisco activity, resulting in plant inability to restore photosynthetic capacity during the recovery period. EpicSelect.4 also showed an increase in WUE under waterlogged conditions, suggesting that sensitive genotypes tended to gain less carbon per unit of water lost. An analogous pattern of increased WUE has been observed in waterlogging-sensitive legumes in previous studies [2 intake compared to the tolerant UCR 369 genotype.Although a contrasting mechanism of photosynthetic damage was demonstrated between tolerant UCR 369 and sensitive EpicSelect.4 genotypes, waterlogging significantly reduced enotypes . Previouon of gs A,B withoand Jmax A,B. Thusr et al. . An incrrlogging D. Taken  peanuts  have demm et al.  also obs studies ,53. Therv/Fm values vary from 0.75 to 0.83, and a reduction from these values indicates damaged PSII. In the current study, the Fv/Fm of EpicSelect.4 genotype was significantly lowered at 3 DOW, and the decrease was below 0.75 from 6 DOW to the end of the experiment  under waterlogging conditions in contrasting cowpea genotypes can be further explored.−2 s−1. Plants were held at a temperature of 30/20 °C (day/night) for a 16/8 h period, respectively. Also, the average relative humidity during the experiment was 63%, 64%, and 70%, respectively, for October, November, and December 2021. Two cowpea genotypes (EpicSelect.4 and UCR 369) with contrasting waterlogging tolerance as determined by Olorunwa et al.  were selBradyrhzobium japonicum  at the rate of 141 g per 22.68 kg of seeds. Four inoculated cowpea seeds of each genotype were planted into one-gallon pots filled with Pro-Mix BX soilless medium  and watered daily. Twice a week, the plants were fertigated with a 5-15-29 water-soluble nutrient solution at the rate of 100 ppm. Plants were thinned to one plant per pot at 14 days after sowing (DAS). After 45 DAS, cowpea plants were subjected to two experimental treatments consisting of waterlogging and control treatments at the R2 growth stage.The cowpea seeds were inoculated before sowing with Cowpea plants were waterlogged by placing 6 pots of each cowpea genotype into five replicated containers . To simulate 7 DOW treatments, the container was filled with tap water to a height of 2–3 cm above the substrate surface. Pots containing cowpea plants were maintained at optimal field capacity under the control treatments. After 7 DOW, the pots were removed from the 15-gallon container filled with water, and plants were allowed to recover for additional 7 days. A, gs, Ci, and E were measured in situ with chlorophyll fluorescence at the North Mississippi Research and Extension Center (10.00–14:00 CST) using an LI-6800 portable photosynthesis system . Measurements were allowed to match the chamber environment before the values were recorded. The chamber environment was set to match the growth chamber, with 1500 µmol m−2 s−1 of light intensity, 415 ppm of CO2 concentration in the air (Ca), and 50% relative humidity. Measurements were conducted on five representative plants of each cowpea genotype subjected to waterlogging and non-waterlogging treatments during waterlogging and recovery. The ratio of A/gs was used to calculate intrinsic water use efficiency (WUE) [Parameters related to gas exchange were measured on the second, most fully expanded trifoliate at 1 to 7 DOW and 1 to 7 days of recovery (DOR). The cy (WUE) .2 response curves (A/Ci) measurements were evaluated using the auto program settings in the LI-6800 at 7 DOR and 7 DOR. To measure the steady-state response of A/Ci, the leaf chamber settings were fixed at 50% relative humidity, 1500 µmol m−2 s−1 light intensity, and the temperature set to maintain ambient greenhouse temperature (28–30 °C). Using the built-in program on the LI-6800, measurements were taken at 50, 100, 200, 300, 400, 500, 600, 800, 1000, 1200, and 1500 ppm CO2, with early matching enabled and wait times of 60–90 seconds between measurements. A/Ci analyses were performed according to Sharkey et al. [http://landflux.org/Tools.php. Representative individual curves were fitted separately, and the extracted parameters were averaged across replicates for each treatment. According to Bernacchi et al. [A/Ci response curve was further utilized to calculate the maximum rate of Rubisco carboxylation (Vcmax), the maximum rate of photosynthetic electron transport (Jmax), and mesophyll conductance (gm).Additionally, the COy et al. , with fey et al.  using thi et al. , the esto) was measured on the second-most fully expanded leaf using a measuring light (0.005 µmol m−2 s−1). The maximal fluorescence (Fm) was quantified using a 1-second saturating pulse at 8000 µmol m−2 s−1 in dark-adapted leaves. The leaves were continuously illuminated for 20 min with an actinic light (1400 µmol m−2 s−1) to record the steady-state yield of fluorescence (Fs). Maximal light-adapted fluorescence yield (F′m) was determined by 8000 µmol m−2 s−1. The actinic light was turned off, and minimal fluorescence yield (F′o) in the light-adapted state was determined after 5 s of far-red illumination. The difference between the measured values of Fm and Fo is the variable fluorescence (Fv). The chlorophyll fluorescence parameters were calculated using the following formulas [v/Fm is the maximal photochemical efficiency of PSII, ΦPSII is the actual photochemical efficiency of PSII, ΦNPQ is the quantum yield for the energy dissipated via Δ pH and xanthophyll-regulated processes, ΦNO is the quantum yield of non-regulated energy dissipated in PSII, and qP and NPQ are the photochemical and the non-photochemical quenching, respectively. The electron transport rate (ETR) of chlorophyll fluorescence was calculated according to Genty et al. [The LI-6800 using pulse-amplitude modulated (PAM) fluorometry with a Multiphase Flash Fluorometer  was used to measure the chlorophyll fluorescence at 1 to 7 DOW and 1 to 7 DOR. During predawn hours (3:00–5:00 CST), the minimal fluorescence  of the functional leaves was measured at 1 to 7 DOR and 1 to 7 DOR using a SPAD  analyzer . The relative CCI of each leaf, represented by the SPAD value, can be used to study the effect of waterlogging on leaf yellowing in cowpea genotypes associated with nitrogen remobilization and leaf senescence. Three readings were collected from each cowpea genotype’s top-most fully expanded trifoliate and averaged.Five representative cowpea plants (from each treatment/replications/genotype) were harvested on 3 DOW, 7 DOW, 3 DOR, and 7 DOR to obtain growth data on the effects of waterlogging stress. The plant component, fresh mass (FM), was measured using a weighing scale from all plants. Plant FM samples were lyophilized using a FreeZone 2.5 L freeze dryer  to determine the dry mass (DM) and percent dry mass (%DM). The cowpea’s relative water content (RWC) was determined as per the method of Barrs and Weatherley  with minp ≤ 0.05 were employed to test the differences between the interactions of factors for measured parameters. The standard errors of the mean were calculated using the pooled error term from the ANOVA table and presented in the figures as error bars. Diagnostic tests, such as Shapiro–Wilk in SAS, were conducted to ensure that treatment variances were statistically equal before pooling. A Pearson correlation analysis was utilized to study the relationship between the studied parameters. Graphs were plotted with GraphPad Prism 9 .The experiment was a randomized complete block design with two waterlogging treatments, two cowpea genotypes, five replications, and twelve plants in a factorial arrangement. In total, 240 plants (5 replicates × 2 waterlogging treatments × 2 cowpea genotypes × 12 plants) were utilized in this study. SAS  was used to perform a statistical analysis of data. A three-way analysis of variance (ANOVA) using the generalized linear mixed model (PROC GLIMMIX) was used to assess the effects of factors , along with their interactions, on the replicated values of CCI, gas exchange, and chlorophyll fluorescence parameters. The experiment’s fixed effects consist of treatment, genotypes, and duration, where the replication (5 levels) was treated as a random effect. The responses of FM, DM, and RWC values were analyzed by a two-way ANOVA with ′genotype’ and ′treatment’ as the main factors. Fisher’s protected least significant difference tests A was mainly driven by decreased gs and gm, with no biochemically limiting declines in Vcmax and Jmax, as well as chlorophyll fluorescence parameters. However, the sensitive EpicSelect.4 showed a significant decrease in A at 2 DOW, with a corresponding reduction in gs, gm, Vcmax, Jmax, Fv/Fm, qP, ETR, and ΦPSII under waterlogged conditions, indicating that stomatal and non-stomatal limited photosynthesis is taking place when the genotype is waterlogged stressed. These waterlogging-induced photosynthetic changes are consistent with rapid leaf chlorosis in cowpea genotypes based on the SPAD values and chlorophyll fluorescence data. In this study, gas exchange and chlorophyll fluorescence parameters were evaluated to reveal the key factors influencing leaf carbon fixation and the adaptive mechanism of cowpea genotypes under waterlogging stress. After 7 DOW and 7 DOR, the tolerant UCR 369 genotype exhibited superior plant growth and photosynthetic efficiency than the waterlogged sensitive genotype, EpicSelect.4. This study confirmed that the ability of UCR 369 to develop adventitious roots and maintain biomass accumulation are critical for waterlogging tolerance. Moreover, the analysis of gas exchange traits revealed that the photosynthetic response to waterlogging differed between tolerant and sensitive cowpea genotypes. At 6 DOW, the downregulation of PSII, ΦNPQ, and qP values in PSII at 2 DOW indicated that sensitive EpicSelect.4 could not absorb energy for photochemical reactions, resulting in damaged photosynthetic apparatus. At the same time, the elevated values of NPQ, 1-qL, and ΦNO in EpicSelect.4 compared to UCR 369 may partly contribute to photoinhibition and decreased photochemical efficiency during waterlogging. Further studies evaluating carotenoid and chlorophyll content are needed to understand the light-dependent response mechanism in tolerant and sensitive cowpea genotypes.Moreover, the downregulation of Φ


We simulate two recent matrix‐isolation experiments at cryogenic temperatures, in which a nitrene undergoes spin crossover from its triplet state to a singlet state via quantum tunnelling. We detail the failure of the commonly applied weak‐coupling method  in describing these deep‐tunnelling reactions. The more rigorous approach of semiclassical golden‐rule instanton theory in conjunction with double‐hybrid density‐functional theory and multireference perturbation theory does, however, provide rate constants and kinetic isotope effects in good agreement with experiment. In addition, these calculations locate the optimal tunnelling pathways, which provide a molecular picture of the reaction mechanism. The reactions involve substantial heavy‐atom quantum tunnelling of carbon, nitrogen and oxygen atoms, which unexpectedly even continues to play a role at room temperature. The spin crossover from triplet to singlet in two nitrene reactions is accompanied by simultaneous heavy‐atom quantum tunnelling. Instanton theory was used to unveil the molecular mechanism of this tunnelling process and, in addition to excellent agreement with experiment, appreciable tunnelling effects were found even at room temperature. Due to their role as versatile reactive intermediates in several important organic reactions, carbenes and nitrenes are molecules of high interest,The feature that makes the reactions cited above amenable to established theoretical methods is that the rate‐determining step takes place adiabatically on a single electronic state, which allows the Born–Oppenheimer approximation to be used. However, due to the two additional non‐bonded electrons on the carbon or nitrogen atom, both carbenes and nitrenes may exist either in their singlet or triplet state, and the spin‐crossover process is nonadiabatic. Three recent studies have presented convincing evidence for nitrene reactions in which the spin crossover is the rate‐determining step. They additionally found that this process is accompanied by tunnelling of hydrogenTheoretical investigations of spin crossovers commonly start by locating the minimum‐energy crossing point (MECP) of the two spin states. Based on the knowledge of the MECP and the reactant minimum, nonadiabatic transition‐state theory (NA‐TST)37, 38As the name of the WC method suggests, it is based on the assumption of weak spin–orbit coupling between the two states, as for Fermi's golden rule. We will demonstrate that the golden‐rule assumption itself is valid for the nitrene reactions under investigation. However, the WC method additionally relies on a crude linear approximation of the potential‐energy surfaces (PESs) around the MECP. While this approximation would be valid for shallow tunnelling at high temperatures, where the reaction proceeds at an energy that lies only slightly lower than the MECP, its applicability to the description of deep tunnelling at energies close to the reactant zero‐point energy (ZPE) cannot be rigorously justified. In this work, we will show that the WC method fundamentally breaks down and leads to unphysical predictions for the deep tunnelling exhibited by the two nitrene reactions. It is hence evident that new theoretical methods are needed to provide reliable insight into the tunnelling mechanism underlying the experimental results.For adiabatic reactions, semiclassical instanton theory has become a well‐established method since it finds an excellent balance between a rigorous theoretical foundation and a high computational efficiency.56, 57The experiments for the two reactions under consideration were carried out at cryogenic temperatures, at which the excited vibrational states are not thermally accessible. Hence, the only mechanism for the reaction to proceed is via nuclear tunnelling out of the vibrational ground state, giving rise to a temperature‐independent plateau of the rate constant in the low‐temperature limit.In this work we will investigate nonadiabatic tunnelling in spin‐crossover processes by considering two specific examples from nitrene chemistry. Although heavy‐atom tunnelling is conventionally thought of as being restricted to cryogenic temperatures, we here unveil the significance of such effects even at room temperature, implying that heavy‐atom tunnelling may surprisingly be relevant under typical reaction conditions of synthetic chemistry.In this work we simulate the cyclization reaction of a 2‐formylaryl nitreneIn the previous studies34, 35The failure of the WC method to capture the physical behaviour of the rate arises from the inherent linear approximation of the potentials around the MECP, which clearly breaks down close to the reactant minimum. The method cannot therefore be expected to give a reasonable description of reactions at very low temperature, where tunnelling takes place dominantly from the vibrational ground state. Moreover, the WC approach is not able to predict possible changes in the reaction mechanism due to multidimensional tunnelling effects such as corner cutting.In order to gain well‐founded theoretical insight into heavy‐atom tunnelling in the two nitrene reactions, we hence need to go beyond the approximations of previous studies. We pay particular attention to the two main aspects of any practical molecular simulation: i) the accuracy of the electronic structure; ii) the validity of the assumptions underlying the rate theory.The crucial importance of the electronic structure arises from the sensitive dependence of rate calculations on the quality of the underlying PESs, on which the nuclear dynamics take place. As detailed in the Supporting Information, our investigations of the two systems under consideration showed that an accurate description of dynamic correlation is of particular importance in these reactions, which rules out the validity of the complete active space self‐consistent field (CASSCF) method alone. In this work, we therefore employ state‐of‐the‐art double‐hybrid density‐functional theory (DFT)τand on the triplet state is βℏ-τ, such that the overall time is related to the inverse temperature, β=1/kBT.Together, these trajectories define the optimal tunnelling pathway, known as the “instanton”.We can go beyond the WC approximation of the rate using semiclassical golden‐rule instanton theory, which provides an accurate description of nuclear quantum effects such as ZPE and multidimensional tunnelling.59, 62τ), which is facilitated by discretizing the trajectories in the form of a ring polymer.[The key computational step is the optimization of this instanton pathway  expression for the rate constant is then given by Equation Δis the spin–orbit coupling measured at the hopping point, Sis the instanton action, given as the sum of the classical actions of the individual states, and Z≠is the instanton partition function, which like the reactant (triplet) partition function ZTcontains translational, rotational and vibrational contributions for each degree of freedom. Note that the vibrational component of Z≠is computed from the second derivatives of the action with respect to the ring‐polymer beads and imaginary time, τ.S/ℏ, which typically increases the rate by accounting for tunnelling effects.where In Figure From Figure It can be seen in the cyclization reaction that the oxygen and nitrogen atoms tunnel toward one another in order to complete the isoxazole five‐membered ring. The oxygen atom contributes 48 % of the squared mass‐weighted tunnelling path length (SMWTPL), closely followed by nitrogen with 35 %.3 group was responsible for the tunnelling.3 group from the carbon to the nitrogen atom takes place after the barrier crossing.The instanton pathway for the isomerization reaction reveals that the bottleneck is the cleavage of the C−C bond, which is overcome by means of heavy‐atom tunnelling. After emerging on the product side of the barrier, the NCO group shifts over to form the C−N bond of the isocyanate product. In this reaction the dominant contribution to the SMWTPL comes from the carbon and nitrogen atoms in the NCO group with 43 % and 34 %. The second carbon and the oxygen atom contribute 7 % and 9 % to the SMWTPL, while the fluorine atoms account for only 7 % in total. It had previously been proposed that the CFFrom the knowledge of the instanton pathways, the rate constants can now be computed using Equation 1). However, in order to effectively account for missing multiconfigurational effects not captured by DFT, we first scaled the potential energies (relative to the reactant minimum) of the MECP and along the MEPs and instanton pathways by the ratio of the MRMP2 and DFT barrier height. This is a common trick to improve the energetics, when higher‐level methods are too computationally expensive for structure optimizations.85, 86. HoweverIn Figure At high temperatures the WC rate constants are in good agreement with the instanton results. In fact, formally both WC and instanton theory have the same correct classical limit equal to NA‐TST. However, at temperatures below 300 K, the WC method overestimates the rate by orders of magnitude compared to experiment and instanton theory. Note that our WC results are different from the ones reported in Ref. The one‐dimensional Wentzel–Kramers–Brillouin (WKB) approximation, which accounts for tunnelling along the MEPs,87, 88We can leverage the accuracy of instanton theory to study the reactions at temperatures where the nitrenes react too quickly to isolate them and measure a rate. While it is expected that tunnelling is the key mechanism for a reaction to proceed at low temperatures, we surprisingly find that even at 300 K nuclear quantum effects continue to speed up the rate of the cyclization and isomerization by factors of 10 and 160 compared to the (fully) classical case. Further comparison to the NA‐TST rate (which includes ZPE but not tunnelling effects) reveals that heavy‐atom tunnelling alone accounts for speed‐ups of 4 and 60.crossover temperature Tc=ℏωb/2πkBwhich depends on the curvature ωbof the barrier top.expTo/T3can be derived,To3=ℏ224mkB3κTκSκT-κS2is defined in terms of the slopes κTand κSof the electronic states at the crossing point.Toas an onset temperature below which tunnelling starts to become important. Due to the cubic dependence on To/Tinside the exponential of the tunnelling factor, the significance of nuclear tunnelling will rapidly increase below this temperature.Although hydrogen‐atom tunnelling is not particularly unusual, and a number of examples of heavy‐atom tunnelling have been reported at cryogenic temperatures,89, 90For the cyclization and isomerization reactions, we obtain onset temperatures of 434 K and 514 K, implying that carbon, nitrogen and oxygen atoms can tunnel even above room temperature. This is in stark contrast to adiabatic reactions, for which the crossover temperature is rarely much higher than 300 K for hydrogen‐tunnelling reactions and typically much lower for heavy‐atom rearrangements, implying that heavy‐atom tunnelling is not significant at room temperature. Note however that the simple tunnelling factor stated above can only be used for a rough assessment about whether tunnelling plays a role in a given reaction. This is due to the linear approximation also inherent in the WC method, which as shown in Figure κTand κShave opposite signs, whereas in the inverted regime (which has a sloped intersection), the gradients are parallel and hence have the same sign. This implies that the onset temperature, which depends inversely on κT-κS, will typically be higher in the inverted regime and therefore that it is more likely to find heavy‐atom tunnelling at room temperature. Additionally, the tunnelling effects in the inverted regime tend to be larger because the instanton action associated with the propagation on the product state contributes with a negative sign leading to a reduced value of S, while in the normal regime both actions are positive leading to a slower rate.κT/Sare large enough.Although this analysis makes it clear that tunnelling is more likely to be important for nonadiabatic reactions than for adiabatic reactions, it is still a rather surprising finding that there is significant tunnelling of heavy atoms at typical laboratory conditions, especially as these reactions are in the Marcus normal regime. While tunnelling is known to be common in the inverted regime from the related field of electron transfer,93, 9414N/15N KIE for both reactions using two independent instanton calculations. Here we discuss only the low‐temperature limit; predictions at higher temperatures can be found in the Supporting Information. Our result of 1.35 for the isomerization reaction is in excellent agreement with the range of experimental values 1.18–1.4414N/15N KIE of 1.4 for the cyclization reaction, which could be verified by future experiments.It is common to measure KIEs as a powerful experimental approach to obtain insight into tunnelling reactions. Therefore, we also computed the 12C/13C and 16O/18O KIEs in the low‐temperature limit for the respective reactions and predict even larger values of 1.8 and 2.4. In this case we used a simple approximate scheme by assuming that the instanton pathway would not change significantly upon isotopic substitution.Our analysis of the instantons above revealed that the NCO‐carbon in the isomerization and the oxygen atom in the cyclization contribute even more to the tunnelling pathway than the nitrogens. We hence computed the We have studied the effects of heavy‐atom tunnelling on low‐temperature spin‐crossover reactions of two nitrenes and obtained quantitative agreement with experimental rate constants. To achieve this level of accuracy, it was necessary to employ MRMP2 calculations on top of double‐hybrid DFT in order to obtain an adequate description of the PESs. However, even with an accurate description of the electronic structure, meaningful results can only be attained with a state‐of‐the‐art rate theory such as the golden‐rule instanton formalism.Our results highlight the shortcomings of the commonly used43, 44T<To).In contrast, the high accuracy of golden‐rule instanton theory demonstrated in this work and in several other studies62, 6414N/15N KIE measured in the isomerization reaction, and in addition, predicted other large nitrogen, carbon and oxygen KIEs, which we hope to be confirmed by future experiments. In future studies, the predictive power of instanton theory could be used to investigate whether these subtle effects can provide tunnelling control of chemical reactions by means of isotopic substitution.[Based on the instanton pathways, we can obtain detailed insight into the rearrangement mechanism. We unveiled substantial amounts of heavy‐atom tunnelling in the reactions of both nitrenes. In particular, we demonstrated the origin of the unprecedentedly large titution.25, 26While in the inverted regime, tunnelling drastically changes the reaction mechanism due to strong corner cutting,While the reactions considered in this work take place in inert‐gas matrices, the description of synthetic chemistry would have to include solvent effects. Although instanton theory cannot simulate liquids explicitly, solvent effects can be approximately accounted for by means of polarizable continuum models, methods based on the spectral density of the bathThe authors declare no conflict of interest.1As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. 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