bluuebunny/crossref_metadata_2025 huggingface dataset:
Gefühlte und reale Arbeitsfähigkeit von
Patient*innen mit Post-COVID Symptomatik nach mildem Akutverlauf: eine
Analyse des Rehabilitation Needs Questionnaire (RehabNeQ)
Authors: Lemhöfer Christina , Best Norman , Gutenbrunner Christoph , Loudovici-Krug Dana , Teixido Lidia , Sturm Christian
Published: November 2021

Hintergrund Das Beschwerdebild der Folgeerscheinungen, die nach einer
COVID-19-Erkrankung auch nach Monaten existieren können, wird immer
deutlicher: das Post-COVID-Syndrom. Neben verschiedenen Symptomen können
auch funktionellen Zusammenhänge bestehen, die die
Arbeitsfähigkeit einschränken. Derzeitige Untersuchungen gehen
von 10% der Infizierten aus, die dies betrifft. In Deutschland
würde dies nach aktuellen Zahlen 380 000 Menschen betreffen. Das
Ziel dieser Analyse war es zu zeigen, wie sich die reale und gefühlte
Arbeitsfähigkeit bei Patient*innen mit Post-COVID Syndrom
darstellt.

Methode Der Rehabilitation Needs Questionnaire wird
routinemäßig bei Patient*innen mit
Post-COVID-Symptomatik bei Vorstellungen in der Medizinischen Hochschule
Hannover bzw. dem Universitätsklinikum Jena ausgefüllt. Es
erfolgte eine deskriptive Analyse der Fragebögen ab April 2021 unter
besonderer Berücksichtigung der Arbeitsfähigkeit. Ausgeschlossen
wurden Patient*innen, die nicht im arbeitsfähigen Alter waren,
oder bereits vor der COVID-19-Infektion arbeitsunfähig.

Ergebnisse 75 von 81 Fragebögen wurden im entsprechenden Zeitraum
von einer Stichprobe im arbeitsfähigen Alter in die Auswertung mit
einbezogen (68% von Frauen, 32% von Männern). Das
Durchschnittsalter lag bei 42,5 Jahren, die Zeit seit der Infektion im Mittel
bei 3 Monaten. 44 der 75 Personen (58,7%) waren zum Zeitpunkt der
Befragung arbeitsfähig. Die empfundene Arbeitsfähigkeit wurde im
Schnitt mit 5,1 von 10 möglichen Punkten angegeben. Frauen zeigten hier
durchschnittlich 6,2 Punkte und Männer 4,7 Punkte. 59,1%
(n=26) der Befragten gaben Schwierigkeiten beim Erhalt von notwendigen
Therapien an. 31 (41,3%) Personen waren zum Zeitpunkt der Befragung
aufgrund der POST-COVID-19-Erkrankung arbeitsunfähig. Das mittlere Alter
der Gruppe lag bei 46,6 Jahren. 16 (51,6%) der 31 Proband*innen
gaben an ununterbrochen seit der Infektion arbeitsunfähig zu sein.
Schwierigkeiten beim Erhalt von notwendigen Therapien hatten in dieser Gruppe
64,5% (n=20).

Diskussion Die Rate derer, die nach einer COVID-19-Erkrankung auch nach
Monaten noch arbeitsunfähig sind, ist hoch. Notwendige therapeutische
Maßnahmen stehen entweder in nicht genügender Anzahl zur
Verfügung oder werden trotz entsprechender Indikation nicht ausreichend
verordnet. Weitere Untersuchungen sind notwendig, um die Wirksamkeit von
Therapien zu belegen und welche Barrieren zur Rückkehr an den
Arbeitsplatz bestehen. Die Auswirkungen können bei weiter steigenden
Fallzahlen noch über Jahre hinweg Einfluss auf die Wirtschaftskraft des
Landes haben.
Therapeutic Effects of Azithromycin on Spinal Cord Injury in Male Wistar Rats: A Role for Inflammatory Pathways
Authors: Rismanbaf Ali , Afshari Khashayar , Ghasemi Mehdi , Badripour Abolfazl , Haj-Mirzaian Arvin , Dehpour Ahmad Reza , Shafaroodi Hamed
Published: November 2021

Background Inflammatory responses, including macrophages/microglia imbalance, are associated with spinal cord injury (SCI) complications. Accumulating evidence also suggests an anti-inflammatory property of azithromycin (AZM).

Material and Methods Male Wistar rats were subjected to T9 vertebra laminectomy. SCI was induced by spinal cord compression at this level with an aneurysmal clip for 60 seconds. They were divided into three groups: the sham-operated group and two SCI treatment (normal saline as a vehicle control vs. AZM at 180 mg/kg/d intraperitoneally for 3 days postsurgery; first dose: 30 minutes after surgery) groups. Locomotor scaling and behavioral tests for neuropathic pain were evaluated and compared through a 28-day period. At the end of the study, tissue samples were taken to assess neuroinflammatory changes and neural demyelination using ELISA and histopathologic examinations, respectively. In addition, the proportion of M1/M2 macrophage polarization was assessed by using flow cytometry.

Results Post-SCI AZM treatment (180 mg/kg/d for 3 days) significantly improved locomotion (p < 0.01) and decreased sensitivity to mechanical (p < 0.01) and thermal allodynia (p < 0.001). Moreover, there was a significant tumor necrosis factor-α (TNF-α) decline (p < 0.01) and interleukin-10 (IL-10) elevation (p < 0.01) in the spinal cord tissue of the AZM-treated group compared with the control groups 28 days post-SCI. AZM significantly improved neuroinflammation as evidenced by reduction of the M1 expression, elevation of M2 macrophages, and reduction of the M1/M2 ratio in both the dorsal root ganglion and the spinal cord tissue after SCI compared with controls (p < 0.01).

Conclusion AZM treatment can be considered a therapeutic agent for SCI, as it could reduce neuroinflammation and SCI sensory/locomotor complications.
Surviving a Self-inflicted Transorbital Pen Intrusion to the Cerebellum: Case Report
Authors: Breuskin David , Ketter Ralf , Oertel Joachim
Published: November 2021

Background Although intracranial traumas by penetrating foreign objects are not absolute rarities, the nature of trauma, the kind of object, and its trajectory make them a one of a kind case every time they occur. Whereas high-velocity traumas mostly result in fatalities, it is the low-velocity traumas that demand an individualized surgical strategy.

Methods We present a case report of a 33-year-old patient who was admitted to our department with a self-inflicted transorbital pen injury to the brain. The authors recall the incident and the technique of the pen removal.

Results Large surgical exposure of the pen trajectory was considered too traumatic. Therefore, we opted to remove the pen and have an immediate postoperative computed tomography (CT) scan. Due to its fragility, the pen case could only be removed with a screwdriver, inserted into the case. Post-op CT scan showed a small bleeding in the right peduncular region, which was treated conservatively. The patient was transferred back to intensive care unit and woken up the next day. She lost visual function on her right eye, but suffered from no further neurologic deficit.

Conclusion Surgical management of removal of intracranial foreign bodies is no routine procedure. Although some would favor a large surgical exposure, we could not think of an approach to do so without maximum surgical efforts. We opted for a minimal surgical procedure with immediate CT scan and achieved an optimal result. We find this case to be worth considering when deciding on a strategy in the future.
The Efficacy of Local Flaps in the Treatment of Traumatic Scalp Defects
Authors: Stepniewski Adam , Lehmann Wolfgang , Schilderoth Maximilian , Behringer Dominik , Emmerich Nadine , Daugardt Julian , von der Brelie Christian , Kauffmann Philipp , Felmerer Gunther
Published: November 2021

Background Scalp defects represent a therapeutic challenge. The aim of this study is to present our experience with local and regional flaps in the treatment of trauma-induced scalp defects. Furthermore, a comparison with other surgical techniques was performed.

Methods A retrospective evaluation of patient records was performed. Only patients who underwent surgery using local flaps between January 2010 and September 2020 due to traumatic scalp defects were included in the study.

Results In all, 10 cases were identified (3 females, 7 males, average age at surgery of 46.5 years [range: 18–82 years]). Six patients underwent surgery due to tissue defects and four due to scar keloids. Three patients experienced minor postoperative complications, one of which required additional surgery. The mean defect size was 35.75 cm2 (range: 4–79 cm2) among the four patients where the defect size could be determined retrospectively. The mean inpatient follow-up was 12.4 days (range: 2–34 days).

Conclusions Local flaps can be widely used. In carefully selected cases, they have the fewest disadvantages of all surgical techniques. In our experience, large angiosomes of the main scalp arteries allow the treatment of defects larger than 30 cm2 with local flaps. Our experience also suggests that the dimensions of flap length to flap width can exceed a ratio of 2:1 in the scalp.
Oral Iron Supplementation in Pregnancy: Current Recommendations and Evidence-Based Medicine
Authors: Duarte Ana Filipa Moreira , Carneiro Ana Catarina Simões Viana , Peixoto Ana Teresa Barbosa Maciel Meira , Montenegro Daniela Filipa Pereira , Campos Débora Sofia Carvalho , Alves Ana Patrícia Ribeiro , Costa Ana Rita Mota Magalhães , Fino Andreia Patrícia Machado
Published: November 2021

Objective To review the evidence about universal iron supplementation in pregnancy to prevent maternal anemia.

Methods Bibliographic research of randomized and controlled clinical trials, meta-analyses, systematic reviews, and clinical guidelines, published between August 2009 and August 2019, using the MeSH terms: iron; therapeutic use; pregnancy; anemia, prevention and control.

Results We included six clinical guidelines, three meta-analyses and one randomized controlled clinical trial.

Discussion Most articles point to the improvement of hematological parameters and reduction of maternal anemia risk, with supplementary iron. However, they do not correlate this improvement in pregnant women without previous anemia with the eventual improvement of clinical parameters.

Conclusion Universal iron supplementation in pregnancy is controversial, so we attribute a SORT C recommendation strength.
The Impact of the COVID-19 Pandemic on Depression and Sexual Function: Are Pregnant Women Affected More Adversely?
Authors: Denizli Ramazan , Sakin Önder , Koyuncu Kazibe , Çiçekli Nayif , Farisoğulları Nihat , Özdemir Mikail
Published: November 2021

Objective To investigate depression and sexual function among pregnant and non-pregnant women throughout the COVID-19 pandemic.

Methods A total of 188 women, 96 pregnant and 92 non-pregnant were included. The Beck Depression Inventory (BDI) and the Arizona Sexual Experience Scale (ASEX) were applied to the participants after obtaining sociodemographic data.

Results The depression scores of pregnant and non-pregnant women were similar (p = 0.846). We found that the depression scores were significantly higher among the group of participants who have lower economic status (p = 0.046). Moreover, the depression score was significantly higher among women who lost their income during the pandemic (p = 0.027). The score on the ASEX was significantly higher, and sexual dysfunction was more prevalent among women who have lower levels of schooling and income (p < 0.05). Likewise, the ASEX scores were significantly higher (p = 0.019) among the group who experienced greater income loss throughout the pandemic. Upon comparing the pregnant and non-pregnant groups, we detected that sexual dysfunction had a significantly higher rate among pregnant women (p < 0.001).

Conclusion In times of global crisis, such as the current pandemic, low-income families have an increased risk of experiencing depression and sexual dysfunction. When we compared pregnant women with non-pregnant women, depression scores were similar, but pregnant women were at a 6.2 times higher risk of developing sexual dysfunction.
A Policy Framework to Support Shared Decision-Making through the Use of Person-Generated Health Data
Authors: Petersen Carolyn , Edmunds Margo , McGraw Deven , Priest Elisa L. , Smith Jeffery R.L. , Kemp Eagan , Campos Hugo
Published: November 2021

Background Individuals increasingly want to access, contribute to, and share their personal health information to improve outcomes, such as through shared decision-making (SDM) with their care teams. Health systems' growing capacity to use person-generated health data (PGHD) expands the opportunities for SDM. However, SDM not only lacks organizational and information infrastructure support but also is actively undermined, despite public interest in it.

Objectives This work sought to identify challenges to individual–clinician SDM and policy changes needed to mitigate barriers to SDM.

Methods Two multi-stakeholder group of consumers, patients, caregivers; health services researchers; and experts in health policy, informatics, social media, and user experience used a consensus process based on Bardach's policy analysis framework to identify barriers to SDM and develop recommendations to reduce these barriers.

Results Technical, legal, organizational, cultural, and logistical obstacles make data sharing difficult, thereby undermining use of PGHD and realization of SDM. Stronger privacy, security, and ethical protections, including informed consent; promoting better consumer access to their data; and easier donation of personal data for research are the most crucial policy changes needed to facilitate an environment that supports SDM.

Conclusion Data protection policy lags far behind the technical capacity for third parties to share and reuse electronic information without appropriate permissions, while individuals' right to access their own health information is often restricted unnecessarily, poorly understood, and poorly communicated. Sharing of personal information in a private, secure environment in which data are shared only with individuals' knowledge and consent can be achieved through policy changes.
Adjusting Insert Thickness and Tibial Slope Do Not Correct Internal Tibial Rotation Loss Caused by PCL Resection: In Vitro Study of a Medial Constraint TKA Implanted with Unrestricted Calipered Kinematic Alignment
Authors: Nedopil Alexander J. , Thadani Peter J. , McCoy Thomas H. , Howell Stephen M. , Hull Maury L.
Published: November 2021

Most medial stabilized (MS) total knee arthroplasty (TKA) implants recommend excision of the posterior cruciate ligament (PCL), which eliminates the ligament's tension effect on the tibia that drives tibial rotation and compromises passive internal tibial rotation in flexion. Whether increasing the insert thickness and reducing the posterior tibial slope corrects the loss of rotation without extension loss and undesirable anterior lift-off of the insert is unknown. In 10 fresh-frozen cadaveric knees, an MS design with a medial ball-in-socket (i.e., spherical joint) and lateral flat insert was implanted with unrestricted calipered kinematic alignment (KA) and PCL retention. Trial inserts with goniometric markings measured the internal–external orientation relative to the femoral component's medial condyle at maximum extension and 90 degrees of flexion. After PCL excision, these measurements were repeated with the same insert, a 1 mm thicker insert, and a 2- and 4-mm shim under the posterior tibial baseplate to reduce the tibial slope. Internal tibial rotation from maximum extension and 90 degrees of flexion was 15 degrees with PCL retention and 7 degrees with PCL excision (p < 0.000). With a 1 mm thicker insert, internal rotation was 8 degrees (p < 0.000), and four TKAs lost extension. With a 2 mm shim, internal rotation was 9 degrees (p = 0.001) and two TKAs lost extension. With a 4 mm shim, internal rotation was 10 degrees (p = 0.002) and five TKAs lost extension and three had anterior lift-off. The methods of inserting a 1 mm thicker insert and reducing the posterior slope did not correct the loss of internal tibial rotation after PCL excision and caused extension loss and anterior lift-off in several knees. PCL retention should be considered when using unrestricted calipered KA and implanting a medial ball-in-socket and lateral flat insert TKA design, so the progression of internal tibial rotation and coupled reduction in Q-angle throughout flexion matches the native knee, optimizing the retinacular ligaments' tension and patellofemoral tracking.
The Current Role of Induced Endometrial Trauma (Endometrial Scratch) in Women Undergoing Infertility Treatment
Authors: Metwally Mostafa , Walters Stephen , Chatters Robin
Published: November 2021

Induced endometrial trauma, otherwise known as endometrial scratch is a simple technique that has been rapidly adopted into clinical practice, mainly for women having IVF treatment, in an attempt to increase pregnancy rates. The introduction of endometrial scratch followed early reports of improved clinical pregnancy rates in women with repetitive implantation failure after having the procedure and follows on from evidence from animal models in the early 20th century suggesting that mechanical trauma to the endometrium can induce decidual changes. Due to the ease and low cost of the procedure, it has been rapidly adopted as an add-on to fertility treatments, in many cases where evidence is still lacking. Despite the initial publication of a large number of studies that demonstrated encouraging improvements in pregnancy rates in women who underwent this procedure, these studies were mainly limited by the small sample sizes and heterogeneity of their study populations, leading to limited validity of the evidence provided by these studies. More recently, three large randomized controlled studies have been published that paint a different picture regarding the value of this procedure. This article explores the evolution of the evidence and the current state of endometrial scratch as an adjuvant therapy for women undergoing IVF treatment.
Similar Healthcare Utilization and 1-Year Patient-Reported Outcomes between Cemented and Cementless Primary Total Knee Arthroplasty: A Propensity Score-Matched Analysis
Authors: Erossy Michael P. , Emara Ahmed K. , Rothfusz Christopher A. , Klika Alison K. , Bloomfield Michael R. , Higuera Carlos A. , Jin Yuxuan , Krebs Viktor E. , Mesko Nathan W. , Molloy Robert M. , Murray Trevor G. , Patel Preetesh D. , Stearns Kim L. , Schaffer Jonathan L. , Strnad Gregory J. , Piuzzi Nicolas S.
Published: November 2021

Cementless fixation for total knee arthroplasty (TKA) has gained traction with the advent of newer fixation technologies. This study assessed (1) healthcare utilization (length of stay (LOS), nonhome discharge, 90-day readmission, and 1-year reoperation); (2) 1-year mortality; and (3) 1-year joint-specific and global health-related patient-reported outcome measures (PROMs) among patients who received cementless versus cemented TKA. Patients who underwent cementless and cemented TKA at a single institution (July 2015–August 2018) were prospectively enrolled. A total of 424 cementless and 5,274 cemented TKAs were included. The cementless cohort was propensity score-matched to a group cemented TKAs (1:3-cementless: n = 424; cemented: n = 1,272). Within the matched cohorts, 76.9% (n = 326) cementless and 75.9% (n = 966) cementless TKAs completed 1-year PROMs. Healthcare utilization measures, mortality and the median 1-year change in knee injury and osteoarthritis outcome score (KOOS)-pain, KOOS-physical function short form (PS), KOOS-knee related quality of life (KRQOL), Veteran Rand (VR)-12 mental composite (MCS), and physical composite (PCS) scores were compared. The minimal clinically important difference (MCID) for PROMs was calculated. Cementless TKA exhibited similar rates of median LOS (p = 0.109), nonhome discharge disposition (p = 0.056), all-cause 90-day readmission (p = 0.226), 1-year reoperation (p = 0.597), and 1-year mortality (p = 0.861) when compared with cemented TKA. There was no significant difference in the median 1-year improvement in KOOS-pain (p = 0.370), KOOS-PS (p = 0.417), KOOS-KRQOL (p = 0.101), VR-12-PCS (p = 0.269), and VR-12-MCS (p = 0.191) between the cementless and cemented TKA cohorts. Rates of attaining MCID were similar in both cohorts for assessed PROMs (p > 0.05, each) except KOOS-KRQOL (cementless: n = 313 (96.0%) vs. cemented: n = 895 [92.7%]; p = 0.036). Cementless TKA provides similar healthcare-utilization, mortality, and 1-year PROM improvement versus cemented TKA. Cementless fixation in TKA may provide value through higher MCID improvement in quality of life. Future episode-of-care cost-analyses and longer-term survivorship investigations are warranted.
Case Studies of Two Classical Imprinting Growth Disorders: Silver–Russell and Beckwith–Wiedemann Syndromes
Authors: Kaur Parminder , Chaudhry Chakshu , Kaur Anupriya , Panigrahi Inusha , Srivastava Priyanka
Published: November 2021

The genetic influences on human growth are being increasingly deciphered. Silver–Russell and Beckwith–Wiedemann syndromes (SRS; BWS) are two relatively common genetic syndromes with under- and overgrowth-related issues being the reason for referral. Aberration in genomic imprinting is the underlying genetic pathomechanism behind these syndromes. Herein, we described a series of children with these two growth disorders and give an orientation to the reader of the concept of imprinting as well as the genetic testing strategy and counseling to be offered in these syndromes.
Posttraumatic Retropharyngeal Pseudomeningocele—A Case Report
Authors: Tyngkan Lamkordor , Singh Vishal , Mathew Vivek , Laharwal Masood Ahmed
Published: November 2021

A retropharyngeal pseudomeningocele after cervical vertebral fracture dislocation is an extremely rare complication and often associated with hydrocephalus. It usually presents with respiratory difficulty and dysphagia, sometimes as an incidental finding in radiological study. We reported a case of 45-year-old female patient who had posttraumatic lower cervical prevertebral retropharyngeal pseudomeningocele, found as an incidental finding in a routine radiological workup. Patient underwent ACDF but expired 2 weeks postoperatively due to respiratory failure. Although the prognosis of retropharyngeal pseudomeningocele depends upon the severity of initial trauma, early recognition and management can prevent enlargement of cyst and development of respiratory difficulty and dysphagia.
Potentially Preventable Primary Cesarean Sections in Future Placenta Accreta Spectrum
Authors: Matthews Kathy C. , Quinn Andrew S. , Chasen Stephen T.
Published: November 2021

Objective Prior cesarean delivery is a well-known risk factor for placenta accreta spectrum disorders. While primary cesarean section is unavoidable in some patients, in others it may not be clearly indicated. The aim of the study is to determine the proportion of patients with placenta accreta spectrum who had a potentially preventable primary cesarean section and to identify factors associated with preventable placenta accreta spectrum.

Study Design This was a single-center retrospective cohort study of women with pathology-confirmed placenta accreta spectrum from 2007 to 2019. Primary cesarean sections were categorized as potentially preventable or unpreventable based on practice consistent with the American College of Obstetricians and Gynecologists and the Society for Maternal–Fetal Medicine “Safe Prevention of the Primary Cesarean Delivery” recommendations. Fisher's exact test and Mann-Whitney U-test were used for comparison with p <0.05 considered statistically significant.

Results Seventy-two patients had pathology-confirmed placenta accreta spectrum over the course of the study period, 15 (20.8%) of whom required a cesarean hysterectomy at the time of primary cesarean section. Fifty-seven patients had placenta accreta spectrum in a pregnancy following their primary cesarean section. Of these, 29 (50.9%) were considered potentially preventable. Most were performed without clear medical indication (37.9%) or for fetal malpresentation without attempted external cephalic version (37.9%). The remainder were due to arrest of labor not meeting criteria (17.2%) and abnormal or indeterminate fetal heart patterns with documented recovery (6.9%). Of the 11 patients without clear medical indication for primary cesarean section, eight (72.7%) were patient-choice cesarean sections and three (27.3%) were for suspected fetal macrosomia with estimated fetal weights not meeting criteria for cesarean delivery. There was no difference in the incidence of potentially preventable primary cesarean sections before and after the ACOG-SMFM “Safe Prevention of the Primary Cesarean Delivery” publication (48.8 vs. 57.1%, p = 0.59). Privately insured patients were more likely to have a potentially preventable primary cesarean section than those with Medicaid (62.5 vs. 23.5%, p = 0.008) and were more likely to have a primary cesarean section without clear medical indication (81.8 vs. 18.2%, p = 0.004).

Conclusion Many patients with placenta accreta spectrum had a potentially preventable primary cesarean section. Most were performed without clear medical indication or for malpresentation without attempted external cephalic version, suggesting that at least a subset of placenta accreta spectrum cases may be preventable. This was particularly true for privately insured patients. These findings call for continued investigation of potentially preventable primary cesarean sections with initiatives to address concerns at the patient, provider, and hospital level.

Key Points
A simple method for estimating the Lorenz curve
Authors: Sitthiyot Thitithep , Holasut Kanyarat
Published: November 2021

Given many popular functional forms for the Lorenz curve do not have a closed-form expression for the Gini index and no study has utilized the observed Gini index to estimate parameter(s) associated with the corresponding parametric functional form, a simple method for estimating the Lorenz curve is introduced. It utilizes three indicators, namely, the Gini index and the income shares of the bottom and the top in order to calculate the values of parameters associated with the specified functional form which has a closed-form expression for the Gini index. No error minimization technique is required in order to estimate the Lorenz curve. The data on the Gini index and the income shares of four countries that have a different level of income inequality, economic, sociological, and regional backgrounds from the United Nations University-World Income Inequality Database are used to illustrate how the simple method works. The overall results indicate that the estimated Lorenz curves fit the actual observations practically well. This simple method could be useful in the situation where the availability of data on income distribution is low. However, if more data on income distribution are available, this study shows that the specified functional form could be used to directly estimate the Lorenz curve. Moreover, the estimated values of the Gini index calculated based on the specified functional form are virtually identical to their actual observations.
Laser requirements for the design of fast laser-driven semiconductor switches for THz and mm-waves
Authors: Schaub S. C. , Cohick Z. W. , Hoff B. W.
Published: November 2021

A reduced parameter model of fast laser-driven semiconductor switches of THz and mm-waves has been developed. The model predicts peak reflectivity and minimum transmissivity of switches, showing good agreement with experimental data, while requiring fewer inputs than published models. This simplification facilitated a systematic survey of laser parameters required for efficient switching. Laser energy density requirements are presented as a function of laser wavelength, laser pulse width, switched frequency, reflection angle, and semiconductor material (silicon or gallium arsenide). Analytical expressions have been derived to explain the dependence of laser requirements on switch parameters and to derive practical minima of required laser energy density. Diffusion is shown to quickly negate the shallow absorption advantage of laser wavelengths shorter than about 500 nm in silicon or 800 nm in gallium arsenide. Decreasing laser pulse width, to a derived limit, and switching S-polarized THz or mm-wave signals are shown to be means of lowering required laser energy. This is an especially useful result for devices operating at high power levels or THz frequencies, where extended switches are used in quasioptical systems.
Wireless photodiode for optical and atomic physics experiments
Authors: Kawalec T. , Sowa P.
Published: November 2021

We show the realization of a simple, small footprint, low power system for wireless transmission of data from a photodiode to an oscilloscope or optionally to a computer. It consists of easily accessible standard modules and electronic parts. Optimization of the setup allowed us to build it around very popular 8-bit microcontrollers and with a minimum number of additional components. The system is particularly suitable for real time, continuous monitoring of spectroscopic signals, light power measurements, optical setup adjustments, and optimization. The average current consumption of the battery powered photodiode and transmitter is as low as 5.2 mA. The system is completed with an optional software oscilloscope, allowing one to visualize the photodiode signal on a computer.
Design and development of a rapid, high voltage capacitor charging power supply based on third order resonant converter topology
Authors: Thekkeppat Reghu , Singh Sonu K. , Lad Mahendra , Bhongade Sandeep , Shrivastava Purushottam
Published: November 2021

A rapid, high voltage capacitor charging power supply (CCPS) based on a third order resonant converter topology has been proposed, analyzed, and simulated using the PSpice software, and as a proof of concept, a prototype of the 6.0 kV, 6.0 A CCPS is also developed. High charging power, low resonant current, and high pulse repetition rate were targeted in the design. In this paper, ac analysis for the calculation of impedance and resonant frequency, and frequency dependence on current gain, and the steady state analysis of the proposed scheme have been studied and presented. The performance is analyzed by simulating the circuit for two values of load capacitances. The simulation and prototype results show linear charging of the load for both values of load capacitances. The charging times of 1.47 and 0.97 ms have been achieved for load capacitances of 1.5 and 1.0 µF, respectively. The performance of the LLC topology has been compared with a conventionally used series resonant scheme. A high charging power of 18.4 kJ/s has been achieved. The topology shows a faster charging rate by ∼36% in comparison with the series LC resonant topology. The results of the analysis match with the simulation and prototype results, which confirms that the proposed scheme is suitable for rapid and reliable CCPS applications.
Prediction of Ti-Zr-Nb-Ta high-entropy alloys with desirable hardness by combining machine learning and experimental data
Authors: Sun Yan , Lu Zhichao , Liu Xiongjun , Du Qing , Xie Huamin , Lv Jiecheng , Song Ruoxuan , Wu Yuan , Wang Hui , Jiang Suihe , Lu Zhaoping
Published: November 2021

Traditional alloy design depends heavily on “trial and error” experiments, which are neither cost-effective nor efficient, particularly for the development of high-entropy alloys (HEAs) using a broad composition space. Herein, we combine a machine learning (ML) model with phase diagram calculations (CALPHAD) to design Ti-Zr-Nb-Ta refractory HEAs with a desirable hardness. The extreme gradient boosting (XGBoost) algorithm is used to train the ML model based on the Ti-Zr-Nb-Ta HEA hardness dataset from CALPHAD-assisted experiments. As a result, the most important features (i.e., the Ta content, melting point, and entropy of mixing) are determined via feature selection and model optimization. Moreover, the high performance of the ML model is validated experimentally, and the prediction accuracy reaches 97.8%. This work provides not only an interpretable ML model that can be used to predict the hardness of Ti-Zr-Nb-Ta HEAs but also feasible guidance for the development of HEAs with desirable hardness.
Environment-friendly regenerated cellulose based flexible memristive device
Authors: Xia Jian , Zhang Zechen , He Huikai , Xu Yichun , Dong Dequan , Yang Rui , Miao Xiangshui
Published: November 2021

Limited nonrenewable resources on earth motivate people to use natural polymer materials in the development of environment-friendly devices for flexible electronics. In this work, a biocompatible and biodegradable organic memristor based on regenerated cellulose is prepared by a facile and green route. Here, cellulose, the key functional layer material, is used as not only the resistive switching layer but also a substrate to construct a flexible self-supporting memristor. Both volatile and nonvolatile resistive switching can be achieved by controlling the compliance current in the SET process. Moreover, this cellulose-based memristor performs competitive environmental and temperature stability compared with other organic memristors. This research provides a facile strategy for constructing an environment-friendly memristor based on natural polymer-based materials.
Improved optical standing-wave beam splitters for dilute Bose–Einstein condensates
Authors: Cassidy Mary Clare , Boshier Malcolm G. , Harrell Lee E.
Published: November 2021

Bose–Einstein condensate (BEC)-based atom interferometry exploits low temperatures and long coherence lengths to facilitate high-precision measurements. Progress in atom interferometry promises improvements in navigational devices like gyroscopes and accelerometers, as well as applications in fundamental physics such as accurate determination of physical constants. Previous work demonstrates that beam splitters and mirrors for coherent manipulation of dilute BEC momentum in atom interferometers can be implemented with sequences of non-resonant standing-wave light pulses. While previous work focuses on the optimization of the optical pulses’ amplitude and duration to produce high-order momentum states with high fidelity, we explore how varying the shape of the optical pulses affects optimal beam-splitter performance, as well as the effect of pulse shape on the sensitivity of optimized parameters in achieving high fidelity in high-momentum states. In simulations of two-pulse beam splitters utilizing optimized square, triangle, and sinc-squared pulse shapes applied to dilute BECs, we, in some cases, reduce parameter sensitivity by an order of magnitude while maintaining fidelity.
Crystal structures and mechanical properties of tungsten monocarbide predicted by first-principles investigations
Authors: Zhang Huai-Yong , Guo Yun-Dong , Min Shuo , Ma Chang-You , Li Jian
Published: November 2021

The crystal structure of tungsten monocarbide (WC) is researched from 0 to 650 GPa through first principles calculations. The results verify that the experimental structure (hP2-WC) with the space group P6¯m2 is the most stable phase in a wide range of pressure. Above 231 GPa, a new stable structure (space group P63/mmc, hP4-WC) is found to be the most stable phase, and it will transform to a CsCl-type phase (cF8-WC) around 582 GPa. Phonon calculations reveal that the hP4-WC phase is dynamically stable and may be a metastable structure at ambient conditions. The cF8-WC phase possesses dynamical stability above 20 GPa. The hP4-WC phase is a low compressible material with a large bulk modulus of 377 GPa at zero pressure. The hardness values of hP2-WC and hP4-WC at zero pressure are 32 and 21 GPa, respectively, while the cF8-WC phase possesses a hardness of 21 GPa at 20 GPa, implying that these phases are potential hard materials. The temperature–pressure phase boundary of WC is obtained by means of the quasi-harmonic approximation method. As the temperature increases, the transition pressure from hP2-WC to hP4-WC remained nearly unchanged. The transition pressure between hP4-WC and cF8-WC decreases with the increasing temperature.
Structural control of asymmetric forebody vortices over a slender body
Authors: Zong Siyu , Wang Yankui , Qi Zhongyang
Published: November 2021

This paper studied a combined control method based on the sensitivity of asymmetric flow over a slender body at a high angle of attack (AoA) to the tip of the nose. The control method adds a particle with a diameter of d = 0.4 mm (0.0044D) and a strake with a variable height on both sides of the tip as the artificial perturbation (AP) and artificial strake (AS), respectively, to control the behavior of forebody vortices. The height h of AS is changed from 0D to 0.055D, where D is the diameter of the slender body. The aerodynamic forces/moments, pressure distributions, and flow structures are measured using force balance, pressure scanning, and particle image velocimetry, respectively. Results show that a specific and predictable pattern of forebody asymmetric vortices is first presented at h/D = 0 because of the specific circumferential location of AP near the tip. Subsequently, as h/D increases, the forebody asymmetric vortices are changed into symmetrical first and then into the opposite asymmetric flow pattern. Thus, the corresponding side force is transformed into zero and then the opposite direction. These results indicate that the changing height of AS easily manages the pattern of forebody vortices and the corresponding side force acting on the slender body. The characteristics of associated aerodynamic forces/moments, pressure distributions, and vertical structures with increasing h are presented in detail.
Internal rotation arena: Program performances on the low barrier problem of 4-methylacetophenone
Authors: Herbers Sven , Zingsheim Oliver , Nguyen Ha Vinh Lam , Bonah Luis , Heyne Bettina , Wehres Nadine , Schlemmer Stephan
Published: November 2021

In the rotational spectroscopy community, several popular codes are available to treat multiple internal rotors in a molecule. In terms of the pros and cons of each code, it is often a difficult task to decide which program to apply to a specific internal rotation problem. We faced this issue when dealing with the spectroscopic fingerprint of 4-methylacetophenone (4MAP), recently investigated in the microwave region, which we here extended into the millimeterwave region. The methyl group attached to the phenyl ring in 4MAP undergoes internal rotation with a very low barrier of only 22 cm−1. The acetyl methyl group features a much higher barrier of about 580 cm−1. The performances of a program using the so-called “local” approach in terms of Herschbach’s perturbative treatment, SPFIT, as well as three programs XIAM, ERHAM, and ntop, representing “global” fits, were tested. The results aim at helping spectroscopists in the decision on how to tackle their own internal rotation problems.
Turbulent jet ignition of ultra-lean methane/air mixture under engine-like condition
Authors: Cai Junqian , Sun Kai , Feng Yizhuo , Jia Ming , Lu Zhen , Shi Lei , Wang Tianyou
Published: November 2021

Turbulent jet ignition (TJI) is a promising technology that enables engines to operate stably at ultra-lean-burn conditions for improved thermal efficiency. In the present work, TJI of an ultra-lean methane/air mixture (excessive air ratio λ = 2.0) under an engine-like condition (temperature of 900 K and pressure of 5.8 MPa) was numerically studied, with particular interest on the ignition patterns and the critical/favorable conditions for successful ignition/rapid combustion. A high-fidelity large eddy simulation was performed, with the linear eddy model being incorporated to account for turbulence–chemistry interaction. To represent the different amount/state of energy released from a pre-chamber, a variety of turbulent jet temperatures, inlet velocities, and orifice diameters were covered. The results identified two successful ignition patterns, including a flame propagation pattern and a jet re-ignition pattern. An ignition regime was also established, with the boundary between ignition success/failure identified by a global Damköhler number (Da) of 0.1. In terms of the combustion rate, heat release in the propagative flame is governed by the growth of the flame surface, which is primarily controlled by stretch and enlarges with the jet Reynolds number (Re). The present results suggest that, for low-reactivity fuels such as methane, the pre-chamber combustion in a TJI system should pursue complete heat release and increase Re and Da simultaneously for the injected turbulent jet into the main combustion chamber.
A new method of predicting network fracture conductivity based on the similitude principle of water and electricity
Authors: Ji Guofa , Chen Shaoqi , Zhou Tong , Huang Zhiwen , Li Fengxia
Published: November 2021

The conductivity of network fracture is a key factor that affects horizontal well production, but using conductivity cells or modified conductivity cells to test it is uncommon. Several theoretical and empirical models have been developed to estimate network fracture conductivity. This paper develops a new method of calculating network fracture conductivity based on the electrical similitude principle and experimental data. Taking into account the network fracture type, test fluid type, proppant combination ratio, and propped type, an experimental scheme is designed, and a series of network fracture conductivities are obtained indoors. Using the formula for seepage resistance R and a calculation procedure chart, the equivalent conductivity of the 20°, 30°, 45°, 60°, and 90° types of network fractures are compared between test data and predictions. Comparisons of our experimental data to the prediction data indicate little error, verifying the accuracy of the new method. This predicting method can provide a reference for the fracture network conductivity optimization of shale reservoir multi-staged fracturing.
Quantitative Imaging in Radiation Treatment Planning
Authors: Buatti John M. , Beichel Reinhard R.
Published: November 2021

Radiation therapy (RT), along with surgery and medical therapies, are the fundamental methods used to treat cancers, as well as a wide range of other diseases. RT is delivered in multiple forms, including external beam therapy, brachytherapy, and radiopharmaceutical therapy. RT is a completely image-guided treatment paradigm, and benefits from advances made in quantitative imaging (QI). The therapeutic effects of radiation are proven, and have improved with each advance, enabling more precisely delivered radiation dose to a tumor target and avoidance of normal tissues. Advances in QI enable improved target and normal tissue definitions, and advances in computer-based algorithmic tools enable enhanced consistency, efficiency, and depth in utilization of the rich information within QI. RT benefits from application of these enhanced tools to imaging to ultimately improve therapy.
Quantitative Imaging in Lung Cancer
Authors: Zhao Binsheng , Dercle Laurent
Published: November 2021

Medical images are used to guide clinicians throughout the course of lung cancer: screening, differential diagnosis of lung nodules, TNM staging, biopsy guiding, radiation treatment planning, and response assessment. Over the past decade, the management of lung cancer patients has radically improved, due to numerous breakthroughs in our understanding of lung cancer molecular characteristics, targeted and immunotherapies, and computer hardware and software. Among innovative technologies, quantitative imaging biomarkers (QIBs) have become promising tools to support clinical decision making. This indicates a paradigm shift, redefining medical images as a quantitative asset for data-driven precision medicine, rather than a qualitative method for estimating disease status. Of note, QIBs, or radiomics signatures, must not only achieve high accuracy, but should also be robust across different imaging acquisition settings, to be clinically applicable and advance patient management. Quantitative imaging (QI) in lung cancer is one of the most active research areas in medical imaging. In this chapter, the current state-of-the-art QI technologies in lung cancer are reviewed, focusing on diagnosis, prognosis, and response assessment. Then, key challenges in QIB development and validation in lung cancer are addressed. Lastly, the importance of establishing quality control tools to ensure reproducible and generalizable QIBs is discussed.
Quantitative Imaging and Bladder Cancer
Authors: Hadjiyski Lubomir , Chan Heang-Ping , Samala Ravi
Published: November 2021

Bladder cancer is a common type of cancer that can cause substantial morbidity and mortality among both men and women. Correct staging of the bladder cancer is crucial for the decision of neoadjuvant chemotherapy and minimizing the risk of undertreatment or overtreatment. A reliable assessment of the response to neoadjuvant therapy at an early stage is vital, to identify tumors that do not respond and allow the patient a chance of alternative treatment. Effective quantitative decision support tools have been developed that merge image-based radiomic and non-image-based biomarkers to assist radiologists and oncologists in assessment of bladder cancer stage and response as a result of treatment. In this chapter, quantitative imaging, image analysis, and machine learning techniques for computer decision support systems for cancer staging (CDSS-S) and for monitoring of bladder cancer treatment response (CDSS-T) are described. A quantitative image analysis tool for bladder cancer (QIBC), which quantifies the bladder gross tumor volume and image characteristics, is an important component of CDSS-S and CDSS-T and its performance is presented. The potential of the CDSS-S and CDSS-T as non-invasive, objective, and reproducible clinical decision support systems for cancer staging and treatment response monitoring has been demonstrated.
Quantitative Magnetic Resonance Imaging Biomarkers for Head and Neck and Thyroid Cancers
Authors: Shah Akash Deelip , Paudyal Ramesh , Hatzoglou Vaios , Shukla-Dave Amita
Published: November 2021

Imaging plays a vital role in diagnosing, planning, and monitoring treatment, and determining prognosis for head and neck and thyroid cancers. Ultrasound, CT, and MRI are first-line modalities for evaluating these tumors, and are excellent at characterizing tumor anatomy and relationship to surrounding structures. With the rise of advanced MRI in recent years, quantitative MRI has demonstrated promise in providing biomarkers for tumor histology, tumor aggressiveness, and prediction of clinical outcomes.
Analytical and Clinical Validation
Authors: Petrick Nicholas , Li Qin , Gavrielides Marios A. , Delfino Jana
Published: November 2021

This chapter focuses on the validation of quantitative imaging (QI) values and quantitative imaging biomarkers. It also discusses best practices for bringing promising QI functions to the market. Analytical validation is assuring the ability of a QI function to process input data to generate reliable QI values correctly; clinical validation is assuring that the QI values achieve a particular purpose in the target population and in the context of clinical care. The major sources of QI measurement error are reviewed first, including those associated with the imaging acquisition process, tool implementation, and reader interpretation. Then, the basic aspects of a high-quality analytical/technical and clinical validation study of a QI value or biomarker are presented. Finally, the regulatory processes encountered when trying to propagate a promising biomarker from a research tool to a regulated medical product for use in clinical practice or a qualified imaging biomarker for use in clinical trials in the United States are discussed.