bluuebunny/crossref_metadata_2025 huggingface dataset:
The social implications of COVID-19 on daily mobility in major cities in Africa. The case of Yaoundé and Douala (Cameroon)
Authors: Ndam Salifou , Chenal Jérôme , Kemajou Armel , Kouomoun Abdou , Diop El Bachir
Published: August 2023

Mobility practices in Cameroon have changed considerably due to the rapid spread of COVID-19. Based on data collection in Yaoundé and Douala, the country’s main cities, which combined 878 questionnaires, 11 interviews and direct observation, this research analysed the mobility practices of city dwellers in a crisis context. Its results reveal social coping mechanisms in the face of the fear of contracting COVID-19. The context was marked by a series of aggravating, structural and cultural factors that influenced the choice of modes of daily travel or the option to remain confined. Four types of modal habits were identified, each responding to individual modal logics during the pandemic: users sensitive to the cost of transport, phobic users, local or short-distance users and exclusive circumstantial motorists.
A Quantitative Approach to Road Safety in Morocco: Reducing Accidents through Predictive Modeling
Authors: Bel-lahcen Marwane , Abdellaoui Alaoui El Arbi , Tékouabou Koumétio Stéphane Cédric , Naggar Othmane Naggar
Published: August 2023

This paper uses machine learning to predict road accidents in Morocco, a country marked by high annual accident rates. Our model employs data such as weather, time of day, and road conditions, derived from historical accidents and environmental records. Findings suggest that such predictive modeling can enable traffic authorities to anticipate high-risk situations and enact pre-emptive safety measures, contributing to significant reductions in road accidents. This study provides a data-driven approach towards policy implementation for road safety, with insights applicable to global road safety initiatives.
Smart-BIM for Smart Cities: Issues and Challenges
Authors: Idrissi Gartoumi Khalil , Koumetio Tékouabou Stéphane Cédric
Published: August 2023

Building Information Modelling (BIM) is implemented in several sectors of the Architecture, Engineering, and Construction (AEC) industry. Faced with the challenges of urban management, smart cities are a response to this situation. Research indicates that BIM is one of the technological approaches with great potential for designing, constructing, and managing smart cities. Despite too few systematic reviews, this paper aims to highlight the potential, opportunities, and challenges of integrating BIM into the smart city environment through a literature review. Based on this review, a classification of issues, trends, and challenges has been made. The paper reveals current research gaps and possible future work in smart city management through information technology, specifically BIM. The focus of this paper contributes to the understanding and promotion of technology for smart cities to address the cumulative challenges of urban environments.
The impact of infrastructure and entrepreneurship support programs on the Female TEA Ratio: A PMG-ARDL approach in an urban context
Authors: Azmi Kamal , Azmi Rida
Published: August 2023

The purpose of this article is to improve our understanding of the factors that influence the Female/Male Total Early-stage Entrepreneurial Activity (TEA) ratio in urban environments. Its goal is to provide policymakers with a solid scientific foundation as well as to suggest new research directions in the field of female entrepreneurship. The study focuses on how macroenvironmental factors influence the Female/Male TEA Ratio in urban contexts within BRICS countries. Several key factors are considered in the analysis, including entrepreneurial finance, government support policies, entrepreneurship support programs, commercial and legal infrastructure, and physical infrastructure. The research findings confirm the hypothesis that commercial and legal infrastructure, as well as government measures to support entrepreneurship, have a negative long-term influence on the Female/Male TEA Ratio by using the PMG-ARDL method and examining data from the Global Entrepreneurship Monitor (GEM). Furthermore, the findings show that entrepreneurship support programs and physical infrastructure have a positive impact on the ratio. However, no significant impact on entrepreneurial finance has been observed in both the short and long term. The article emphasizes the importance of taking into account the regional dimension when developing entrepreneurship support policies, as well as the unique characteristics of each urban area.
Town scale response of water viral communities to town source surface water contamination with hydrochemical parameters
Authors: Opere Wasonga Michael
Published: August 2023

This study aims to explore the relationship between human enteric viruses found in town-scale surface water sources and certain chemical contaminants present in the water. From October 2010 to April 2012, water samples were collected and analyzed using a combination of biophysical and molecular techniques to detect the presence of human adenoviruses (HAdV) and human enteroviruses (HEV) as well as chemical parameters as predictors for virus survival. The concentrations of 12 chemical contaminants were found to be within WHO-recommended limits. The study found positive and negative associations between viral genome detection and four out of the 12 metal and nonmetal analytes. Specifically, there was a correlation between Cd and HAdV genome detection (rho = 0.146, p = 0.032) and between Pb and Fe with HEV (rho = 0.156, p = 0.022) and (rho = 0.148, p = 0.029), respectively. For nonmetals, phosphates were slightly negatively correlated to HEV (rho = 0.174, p = 0.010). The results of the study did not provide support for the hypothesis of an association between the presence of human enteric viruses and the levels of twelve chemical contaminants.
Neutrophil Activation Subsequent to Cardiopulmonary Bypass: A Sensitive Method for Determining Neutrophil Activation by Quantification of Lactoferrin Concentrations
Authors: McQueen Patrick J. , Bowers M.C. , Larson Douglas F.
Published: August 2023

Neutrophils have been implicated as contributors to the pathogenesis of cardiopulmonary bypass (CPB). We report a method to quantify the extent of neutrophil activation during CPB through measuring the serum concentrations of lactoferrin. We developed a modified enzyme-linked immunosorbent assay (ELISA) for the quantification oflactoferrin that is sensitive to 1 ng/ml. The preliminary data acquired to support this method confirm that there is a time-dependent increase in neutrophil activity during CPB. This was determined by measuring lactoferrin serum concentrations, and the lactoferrin concentrations appear to be higher in the pediatric patient compared to the adult patient.
An In Vitro Analysis of a One-Way Arterial Check Valve
Authors: Springer Michael A. , Korth Douglas C. , Guiterrez Pamela J. , Morrow John F. , Stammers Alfred H.
Published: August 2023

The utilization of a centrifugal pump during extracorporeal circulation may result in retrograde blood flow through the circuit. The non-occlusive characteristics of a centrifugal pump could create a condition where regurgitant flow is possible when the pressure in the cannulated vessel exceeded the pressure in the extracorporeal circuit. The reversal of flow, from patient to pump, could entrain air from multiple points including cannulation sites, suture holes, or open vessels or chambers. The following study was conducted to evaluate the ability of an arterial check valve (ACV) to prevent retrograde flow.

An in vitro circuit was designed to evaluate the flow dynamics of an ACV under a variety of test conditions including the following: flow rates between 0 and 7.5 L/min, and at temperatures of 37°, 25° and 15°C. The design characteristics of the ACV permitted easy priming, aided by gentle turbulence at the junction of the valve attachment to the casing. There was no difference in pressure drop across the ACV at any flow when compared to an identical circuit without the valve. The pressure drop across the ACV never exceeded 5 mmHg, at any temperature, when flow was less than 2 L/min. Retrograde leak volume was determined by creating "back" pressures on the valve, ranging from 25 to 500 mmHg. One ACV malfunctioned at a back pressure of 250 mmHg, and the data for that valve was omitted for comparative purposes. On the remaining valves, leak volume did not exceed 1.2 ml, and was a result of the compliance of the leaflet structures causing a slight volume displacement due to valve motion in a retrograde fashion. The results of this study show that the ACV permitted unimpeded, unidirectional flow at all operating conditions considered clinically relevant, and may be efficacious in alleviating the chance of retrograde circuit flow.
How to Do It: A Versatile Carmeda Coated Cardioplegia System
Authors: Price David R. , Martin John , Gough Jeffrey D. , Stearns Gary T.
Published: August 2023

A biocompatible Carmedacardioplegia system was developed at Rhode Island Hospital for the administration of crystalloid and blood cardioplegia. The system uses a venous reservoir bag, a single pass heat exchanger with bubble trap, and a roller pump to circulate the cardioplegia solution. Because a Carmeda coated cardioplegia system does not exist, we designed a system that could be incorporated into a Carmeda coated cardiopulmonary bypass circuit.
Cardiopulmonary Bypass Support for Tricyclic Poisoning: A Case Report
Authors: Sheppard Carl
Published: August 2023

Cardiopulmonary bypass as an adjunct to the treatment of acute tricyclic antidepressant poisoning has not been well documented in the literature. In December of 1993, Providence Medical Center used such an adjunct for cardiac support on a 17 year old male with acute tricyclic antidepressant poisoning. The patient had ingested 2500 to 3500 mg of imipramine. Lab tests confirmed imipramine ingestion and ruled out alcohol, acetaminophen or salicylate combinations. The patient arrived via ambulance to the emergency room with a coarse supraventricular rhythm with wide QRS complexes. Over the next 20 minutes the QRS complex became increasingly wider and the rhythm more bizarre until pulses were lost. Repeated attempts to correct the dysrhythmia were unsuccessful and cardiopulmonary resuscitation was eventually initiated. The patient was transported to the operating room and placed on cardiopulmonary bypass. After several hours of bypass and charcoal hemoperfusion, the patient's cardiac rhythm improved to a supraventricular rhythm. The patient was weaned from bypass and transferred to the cardiac care unit where hemodetoxification continued. Postoperatively the patient had a cardiac index of 2.4 L/min/m2 and systemic vascular resistance of 942 dynes/sec/cm-5 on norepinephrine of 2 mcg/kg/min. Imipramine and desipramine levels were down to 250 ng/ml and 500 ng/ml respectively. Neurologic function, however, did not resume and life support was terminated on postoperative day three.
A Perfluorocarbon Emulsion Prime Additive Improves the Electroencephalogram and Cerebral Blood Flow at the Initiation of Cardiopulmonary Bypass
Authors: Vocelka C. , Spiess B. , Soltow L. , Thomas R. , Gohra H. , Akimoto H. , Rothnie C. , Kunzelman K. , Verrier E. , Cochran R.P.
Published: August 2023

Depression in electroencephalogram (EEG) has been documented clinically and is reproducible in swine at the initiation of cardiopulmonary bypass (CPB) utilizing a crystalloid prime. The physiological cause of this transient alteration in electrical brain activity appears to be associated with the transient drop in arterial pressure. The etiology is unknown but may be attributable to the bolus of the crystalloid prime or micro emboli, either air or fibrin-platelet.

Thirteen swine (17-26 kg) were anesthetized and received 4 mg/kg dexamethasone, and following a tracheotomy were ventilated with halothane in 100% O2. Surgical preparation included: sternotomy and preparation for right atrial- aortic CPB. The CPB circuit consisted of a hollow fiber membrane oxygenator, a hard-shell venous reservoir, a roller pump, and PVC tubing. The circuit was randomly primed with either 1200 ml Plasmalyte-A or 10 ml/kg perfluorocarbon emulsion (PFE) and Plasmalyte-A to total 1200 ml. The animals were monitored continuously for systemic hemodynamics and electrocardiogram, and cerebral monitoring included blood flow and bitemporal EEG. Arterial blood gases were measured and PaCO2 was kept between 30-45 mmHg both before and during CPB. Cerebral blood flow (CBF) was measured pre-CPB and at 10 minutes after initiation of CPB. Bitemporal computerized EEG was analyzed every 60 seconds. Total power of each hemisphere, power in frequency bands, and spectral edge were recorded.

All animals demonstrated a relative decrease in EEG total power at the onset of CPB. Animals that received PFE demonstrated a more stable arterial blood pressure, an increased CBF, and a lesser decrease and an earlier recovery of the EEG power. The differences in hemodynamics and EEG in the PFE prime group may be beneficial in decreasing the neuro-psychological changes associated with CPB and needs further investigation.
Accuracy of In-Line Venous Saturation and Hematocrit Monitors in Pediatric Perfusion
Authors: Yaskulka Scott M. , Burnside Jeff , Bennett Denise , Olshove Vince , Langwell Jim
Published: August 2023

Cardiopulmonary bypass (CPB) in neonates and infants routinely employs lower blood flow rates (BFR), temperatures, and hematocrits (Hct) than those typically observed in adult CPB. The purpose of this study was to evaluate the accuracy of three devices available for continuous inline measurement of venous oxygen saturation (SvO2) and Hct during pediatric CPB.

Venous blood samples were obtained over a range of BFR, temperatures, and Hct and analyzed on a Corning 2500 Co-Oximeter and HematoStat C-70 centrifuge. These values were then compared to those measured by the Bentley OxySat SM-0200, the Gish StatSat, and the 3M CDI 100 in-line monitors.

Seventy samples were obtained and analyzed using linear regression, paired t-test and residual analysis to establish the reliability and accuracy of each device. The results demonstrate the CDI to be more statistically accurate (p > 0.05) than the Gish and Bentley devices for measuring SvO2 in nearly all circumstances, though all correlated well with the control (r > 0.70). When comparing spun Hct to the CDI and Gish values, the CDI in-line monitor demonstrated a greater reliability to predict actual patient Hct (r > 0.90) than the Gish StatSat (r > 0.60). Residual analysis revealed that even though the Gish StatSat had higher calculated p values (p > 0.05) than the CDI 100 for interpreting Hct, it was shown to display more inconsistent and sporadic values over the ranges of BFR and temperature studied. It is concluded that the CDI I 00 proved to be more accurate, reliable, and consistent than the Gish StatSat and the Bentley Oxysat devices in determining SvO2 and Hct over all evaluated parameters in this study.
A Clinical Evaluation of the Terumo Capiox SX1BR Hollow Fiber Oxygenator
Authors: Dekkers Perry A. , Lawson D. Scott , Smigla Gregory R. , Shearer Ian R.
Published: August 2023

The Terumo Capiox SX18R is a commercially available, low prime, reverse phase, hollow fiber membrane oxygenator. The oxygenator consists of a 1.8 m2 microporous polypropylene hollow fiber bundle, a 2200 cm2 tubular stainless steel heat exchanger. and an open hard shell venous reservoir with integral cardiotomy filter.

The Terumo Capiox SX 18R oxygenator was evaluated to determine its clinical oxygenating performance. Blood samples were drawn from 25 patients yielding 114 data points. The following parameters were recorded: blood flow, cardiac index, gas flow, gas to blood flow ratio, and oxygen fraction. Samples were assayed for hematocrit, hemoglobin, arterial and venous blood gas values, and venous oxygen saturation. The data and assay results were used to calculate arterial, venous, and membrane gas oxygen content, oxygen transfer, shunt fraction, and oxygen diffusion capacity.

The Terumo Capiox SX18R oxygenator performed adequately with sufficient oxygen transfer reserve and carbon dioxide clearance under a variety of clinical conditions for the tested population.
Correlation of ACT as Measured with Three Commercially Available Devices with Circulating Heparin Level during Cardiac Surgery
Authors: Niles Scott D. , Sutton Robin G. , Ploessl James , Pennell Beverly
Published: August 2023

Automated activated clotting time (ACT) is utilized as the primary means of assessing anticoagulation status for cardiopulmonary bypass (CPB) procedures. Influences on the clotting cascade during CPB such as hypothermia, hemodilution, and platelet dysfunction are known to affect ACT.

The recently introduced Thrombolytic Assessment System (T AS) has been reported to be less sensitive to changes in hemodilution and hypothermia during CPB than more conventional ACT devices. This study evaluated the ability of TAS, and two other commercially available automated ACT systems, the HemoTec and Hemochron, to correlate with circulating heparin levels. Reference standards for circulating heparin were determined by inactivation of factor Xa assay.

Nineteen patients undergoing moderate hypothermic CPB served as subjects for this investigation. Blood samples were obtained for study at four time periods: 1) baseline (control), 2) post heparin administration (300-400 U/kg) prior to CPB, 3) during CPB, and 4) post protamine. Study results demonstrated a high correlation between the HemoTec and Hemochron (r = 0.99), increased heparin dose response on CPB compared to pre-CPB activity (p < 0.05), and a significant (p<0.05) negative correlation between devices and patient hematocrit during CPB. Additionally, device correlation with anti-Xa assay during collection periods 2 and 3 showed negative correlations in each of the three devices evaluated.

We conclude that all automated devices tested demonstrated an inability to predict circulating heparin at levels necessary for CPB, and that these discrepancies become magnified during CPB procedures.
A Comparison of Static Occlusion Setting Methods: Fluid Drop Rate and Pressure Drop
Authors: Rath Thomas , Sutton Robin , Ploessl James
Published: August 2023

Tubing circuits primed with water were constructed on two roller pumps to characterize and compare two static methods of setting the occlusion on roller pumps (fluid drop rate and pressure drop rate).

Twelve separate experiments were performed in which PVC boot tubing diameters (1/2 in, 3/8 in and 1/4 in), roller position (each roller alone on a two roller pump) and roller occlusion (total occlusion to 0.004 in underocclusion) were varied. Fluid drop rates were measured from two heights (30 in and 1 m) above the pump head where drops of 1 em and 1 in were timed for each occlusion setting. Pressure drop was measured by clamping the outlet tubing, injecting fluid into the tubing between the clamp and roller elevating the pressure to 300 mmHg and observing the rate that it dropped at each occlusion setting.

Fluid drop rate and pressure drop rate were positively correlated at all occlusion settings and tubing sizes (p < 0.001). Using a single roller occlusion and an optimal fluid drop rate of .5 to 1.5 cm/min. at 30 in height, pressure drops (mmHg/min.) were (mean± SD); 1/2 in tubing= 263 ± 33, 3/8 in= 241 ±52, 1/4 in= 264 ± 11. For a fluid drop rate of 1.27 to 3.81 cm/min. at 1m height, pressure drops were (mean± SD); 1/2 in= 266 ± 33, 3/8 in=278 ± 17, 114 in=274 ± 20. The occlusion settings or occlusion gap varied significantly (p < 0.001) between pumps and tubing sets. Thus, it appears as though pressure drop rate can predict fluid drop rate at just nonocclusive pump settings; however, the occlusion should be rechecked every time a different pump or boot tubing is used.
Monitoring Anticoagulation During Aprotinin Utilization
Authors: Schaadt Jennifer
Published: August 2023

The literature reviewed discussed the varying practices of anticoagulation measurement in those open heart patients receiving aprotinin. All references have reported an increase in celite ACTs (C-ACTs) in heparinized patients who were treated with aprotinin. Two authors attributed this effect to aprotinin's ability to enhance heparin's anticoagulation and therefore permit a decrease in the heparin dose. Other authorities proved that during aprotinin administration the C-ACTs were artificially prolonged and that the C-ACT should either be maintained at 750 seconds or greater, or not be used at all. An alternative is the kaolin ACT (K-ACT), which is not affected by aprotinin except at serum levels above 500 KIU/ml. An additional method of measurement is the high dose thrombin time (HITT), a test that is not affected by variables that alter the C and K-ACTs but is inaccurate at low heparin levels. There appears to be no ideal method to provide an accurate anticoagulation measurement when considering aprotinin's effect on the hemostatic system. Based on these data, the anticoagulation protocol remains an institutional decision in determining which measurement method will render cardiopulmonary bypass safe and effective when aprotinin is used.
The Use of Retrograde Cerebral Perfusion in a Patient with Acute Ascending Aortic Dissection Following Elective Coronary Bypass Surgery :A Case Report.
Authors: Ruby Dale L.
Published: August 2023

A 74 year old male patient presented with congestive heart failure and significant multivessel coronary artery disease. Following successful coronary artery bypass surgery, the patient developed an acute dissection of the ascending aorta. The patient was placed back on cardiopulmonary bypass and deep hypothermic circulatory arrest was instituted while the ascending aortic dissection was repaired. In an attempt to preserve brain tissue and decrease cerebral edema during hypothermic arrest, a modified form of retrograde cerebral perfusion was used. The patient tolerated the procedure and was weaned from cardiopulmonary bypass with the help of an intraaortic balloon pump. On the second postoperative day, the patient woke up and responded appropriately to verbal commands.
In Vitro Testing of a Current Cell Salvaging Device for the Removal of Malignant Cells from Contaminated Blood
Authors: Leach Duncan Neil , Willingham Mark , Ecklund Jodie
Published: August 2023

The efficiency of a current cell washing device for removing tumor cells from bovine blood was examined under laboratory conditions. In the in-vitro laboratory, anticoagulated bovine blood was seeded with known numbers of immunocytochemical stained human malignant epithelial cells (KB) grown in culture. The blood was subjected to cell washing. Blood samples were taken before and after cell washing for identification of the tumor cells. The samples were then analyzed under florescence microscopy and pre- and post-cell washing tumor cell counts in 20 microscopic fields were recorded. It was determined that the mean tumor cell removal efficiency was 86% ± 13% using the cell salvaging technique. Two-way ANOVA revealed a significant difference between the pre- and post-cell washing samples (p<0.001) with no difference between trials (p=NS). The results are discussed in terms of the potential safety of cell salvaged blood for the surgical care patient.
Perfusion for the jehovah's Witness Patient: An Example of Protocol Variability
Authors: Raley Richard A. , Split Robert C.
Published: August 2023

Several translated verses in the New and Old Testaments provide Jehovah's Witnesses with influential guidance when they are to undertake a surgical procedure. These patients refuse to accept homologous blood or its components for transfusion. They also refuse to accept autologous blood for re-transfusion if it has been isolated from the body. This case report communicates the perfusion protocol variations in equipment selection, hemostasis management. and religious respect that resulted in optimal cardiac surgery for a Jehovah's Witness.
Tables for Estimating Dilutional Hematocrits and Blood Flow Rates from Total Blood Volume and Body Surface Area Formulae
Authors: Searles Bruce , O’Leary Colleen E.
Published: August 2023

This paper provides a historical look at the development of formulae for predicting body surface area and total blood volume. A variety of experimental methods used for the development of body surface area and total blood volume formulae are briefly reviewed. The varying results of different formulae and nomograms are considered in relation to their impact on calculations typically used for the cardiopulmonary bypass patient. Charts are provided which will aid the clinician in the determination of body surface area, relative perfusion output, total blood volume, and resultant hematocrit.
The Novacor Left Ventricular Assist System: Lessons Learned
Authors: Samuels Louis E. , Kaufman Marla S. , Morris Rohinton J. , Brozena Susan C. , Twomey Carol , Brockman Stanley K.
Published: August 2023

The purpose of this investigation is to identify the factors influencing the outcome of the Novacor left ventricular assist system (LV AS) as a bridge to transplant. Novacor LV ASs were placed for transplant candidates refractory to medical therapy. All LV ASs were performed on cardiopulmonary bypass without aortic cross clamping. Postoperative care was instituted per protocol. From October 9, 1993, to October 29, 1996, 17 Novacor LV ASs were placed as a bridge to transplantation. There were I 5 male and 2 female patients. The mean age was 52 years (16-66 years). The mean time interval from listing for orthotopic heart transplantation (OHT) to LV AS insertion was 55 days (1-307 days). The mean cardiopulmonary bypass time was 108 minutes (53-300 minutes). Ten (59%) patients were subsequently transplanted. Prior to transplant, seven (41%) patients expired of neurologic sequellae, right ventricular failure, or sepsis syndrome. The mean duration of LVAS support to transplantation was 31 days (1-76 days). The average blood loss for the first 24 hours was 4096 ml (500-16,105 ml). Eight patients remain alive at a mean follow-up of 13 months (1-22 months). Two patients expired of heart failure following transplantation. Preoperative cardiogenic shock and infection result in poor outcome following LV AS insertion. Severe right ventricular (RV) dysfunction requires prompt RV AD placement. Correction of preoperative coagulopathy and meticulous hemostasis are critical.
Automatic Control of Gas Exchange During Cardiopulmonary Bypass
Authors: Merz Scott I. , Montoya J. Patrick , Lee W. Anthony , Kolla Srinivas , Bartlett Robert H.
Published: August 2023

An automatic control system was devised that regulates gas exchange during cardiopulmonary bypass (CPB). The Automated Extracorporeal Gas Exchange System (AEGES) controls the blood flow rate and/or the flow of gas to the oxygenator in order to meet user-defined setpoints for PO2 and PCO2 of blood drained from the patient while maintaining safe pressures in the CPB circuit and/or the patient’s circulation. Venous blood gases were used as the basis for control because they reflect the amount of oxygen/CO2 consumed/produced by the patient given the present rate of delivery via CPB. In the event of an alarm or upon the perfusionist’ s command, AEGES reverts to manual control of blood flow and/or sweep flow.

AEGES was tested in a hypothermia model of CPB in sheep, where it successfully regulated PO2 and PCO2 within 5% of setpoint during cooling from 38 to 25°C. In order to control the blood gases to setpoints of PO2=45 mmHg and PCO2=40 mmHg in the venous drainage, AEGES reduced blood flow from 2.4 to 1.6 L/min and sweep flow from 2.2 to 0.7 L/min.

AEGES is intended to act as a tool for the perfusionist to assist in maintaining consistent blood gas conditions. AEGES can be integrated with other control systems (e.g., reservoir level control and blood temperature control), further automating the CPB procedure; however, in no way could this system replace the perfusionist.
Urethral Perfusion for Cryoablation of the Prostate
Authors: Huffman Suzanne M. , Newberry Jamie , Fristoe Lance W. , Stammers Alfred , Grune Martin
Published: August 2023

Cryosurgery is an emerging treatment method for prostate cancer patients that may expand the scope of practice for perfusionists. Because of the low temperatures needed to cryogenically destroy cancerous tissue, damage to the urethra and bladder may cause incontinence and impotence. As a result of this associated morbidity, an extracorporeal circuit was constructed by the perfusionists at the University of Nebraska Medical Center (Omaha, NE). This urethral perfusion circuit provides a way to maintain normothermic urethral and bladder temperatures during cryogenic procedures, thus preventing trauma to the urethra and bladder.

Five patients with a mean age of 73.3 ± 3.0 years diagnosed with localized prostate cancer (Stage A, B, C) were offered cryosurgery using urethral perfusion to treat their cancer. After induction of general anesthesia, a specially designed urethral catheter was inserted. Quarter-inch tubing was attached to barbed connections on the catheter and the free ends were then attached to the circuit. This extracorporeal circuit consisted of a heater/cooler, a twin roller pump, a cardioplegia heat exchanger, and temperature and pressure monitoring devices at the inlet and outlet sites on the catheter. Normal saline was circulated through the tubing of the urethral perfusion circuit to maintain flow rates of 200-400 ml/min, with the circuit pressure not exceeding 300 mmHg.

Average urethral perfusion time was 139.3 ± 17.7 minutes. Inlet temperature of the catheter was kept at 42° C to maintain an average bladder temperature of 38.2 ± 2.3° C. All of the patients tolerated the procedure well and were ambulating without assistance on postoperative day one. With the exception of one patient with acute postoperative anuria, patients were discharged on the first postoperative day. Cryosurgery of prostate cancer using urethral perfusion has the potential to serve as a unique practice opportunity for perfusionists.
The Efficacy and Safety of a Pharmacologic Protocol for Maintaining Coronary Artery Bypass Patients at a Higher Mean Arterial Pressure during Cardiopulmonary Bypass
Authors: Pirraglia Paul A. , Peterson Janey C. , Hartman Gregg S. , Yao Fun Sun F. , Thomas Stephen J. , Charlson Mary E.
Published: August 2023

A recent randomized trial of higher versus lower mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) showed that higher MAP on CPB was associated with a lower incidence of overall cardiac and neurologic morbidity and mortality in coronary artery bypass graft surgery (CABG) patients. Cardiopulmonary bypass MAP was controlled pharmacologically while CPB flow was held constant for any given period. The objective of the present study was to assess the efficacy and safety of this pharmacologic protocol. Two hundred forty-eight patients participated in the study; the mean age was 65.8 ± 9.4 years, 20% were women, and the mean preoperative ejection fraction was 48%. The low-flow conrrected CPB MAP attained for the low and high MAP groups was 56.7 ± 5.0 mmHg and 77.7 ± 7.1 mmHg, respectively (p = 0.0001). Major cardiac and neurologic outcomes, postoperative blood loss, renal dysfunction, intensive care unit (ICU) stay, and duration of intubation were not found to be significantly associated with any drug in the pharmacologic protocol. These findings support that the pharmacologic protocol used to maintain CABG patients at higher MAP on CPB is both efficacious and safe.
Dermatologie
Authors: Baierl Bettina
Published: August 2023

Die 52. Tagung der Deutschen Dermatologischen Gesellschaft e. V. (DDG) vom 26. bis 29. April 2023 in Berlin widmete sich den von Klimawandel verursachten Veränderungen aus dermatologischer Sicht, aber auch seltenen Erkrankungen aus dem Bereich der pädiatrischen Dermatologie.
Schulen im (Klima-)Wandel – Handlungsfelder
Authors: Sobek Carolin , Ober Peggy , Vogel Mandy
Published: August 2023

Die Grundlagen bewusster umweltbezogener Einstellungen und Verhaltensweisen werden früh gelegt. Kindergärten und Schulen als Orte des gemeinsamen Lebens und Lernens können – neben dem Wissen – nachhaltige Normen und Werte vermitteln und festigen. Diese ermöglichen es den Kindern, Maßnahmen gegen den Klimawandel zu verstehen und als selbstverständlich in ihrem Leben zu akzeptieren. Schulverpflegung, Schulweg und Schulgärten sind einige mögliche Handlungsfelder. Sie können genutzt werden, Kinder für umweltrelevante Themen zu sensibilisieren und so auch zukünftigen Generationen eine lebenswerte Umwelt zu sichern.
Effect of Alirocumab Added to High-Intensity Statin on Platelet Reactivity and Noncoding RNAs in Patients with AMI: A Substudy of the PACMAN-AMI Trial
Authors: Ueki Yasushi , Häner Jonas D. , Losdat Sylvain , Gargiulo Giuseppe , Shibutani Hiroki , Bär Sarah , Otsuka Tatsuhiko , Kavaliauskaite Raminta , Mitter Vera R. , Temperli Fabrice , Spirk David , Stortecky Stefan , Siontis George C. M. , Valgimigli Marco , Windecker Stephan , Gutmann Clemens , Koskinas Konstantinos C. , Mayr Manuel , Räber Lorenz
Published: August 2023

Objective The effect of the PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor alirocumab on platelet aggregation among patients with acute myocardial infarction (AMI) remains unknown. We aimed to explore the effect of alirocumab added to high-intensity statin therapy on P2Y12 reaction unit (PRU) among AMI patients receiving dual antiplatelet therapy (DAPT) with a potent P2Y12 inhibitor (ticagrelor or prasugrel). In addition, we assessed circulating platelet-derived noncoding RNAs (microRNAs and YRNAs).

Methods This was a prespecified, powered, pharmacodynamic substudy of the PACMAN trial, a randomized, double-blind trial comparing biweekly alirocumab (150 mg) versus placebo in AMI patients undergoing percutaneous coronary intervention. Patients recruited at Bern University Hospital, receiving DAPT with a potent P2Y12 inhibitor, and adherent to the study drug (alirocumab or placebo) were analyzed for the current study. The primary endpoint was PRU at 4 weeks after study drug initiation as assessed by VerifyNow P2Y12 point-of-care assays.

Results Among 139 randomized patients, the majority of patients received ticagrelor DAPT at 4 weeks (57 [86.4%] in the alirocumab group vs. 69 [94.5%] in the placebo group, p = 0.14). There were no significant differences in the primary endpoint PRU at 4 weeks between groups (12.5 [interquartile range, IQR: 27.0] vs. 19.0 [IQR: 30.0], p = 0.26). Consistent results were observed in 126 patients treated with ticagrelor (13.0 [IQR: 20.0] vs. 18.0 [IQR: 27.0], p = 0.28). Similarly, platelet-derived noncoding RNAs did not significantly differ between groups.

Conclusion Among AMI patients receiving DAPT with a potent P2Y12 inhibitor, alirocumab had no significant effect on platelet reactivity as assessed by PRU and platelet-derived noncoding RNAs.
A Study of the Current Scenario of the Obstetrics and Gynecology Residency during the COVID-19 Pandemic
Authors: Sonnenfeld Marina Martinelli , Nozaki Alexandre Massao , Genova Anelise Silva de , Ristow José Ricardo Weitz , Moura Tamiris Ferreira de , Cabral Rayanne Pereira , Garcia João Victor Almeida , Guimarães Camila Abdias , Oliveira André Luiz Malavasi Longo de , Francisco Rossana Pulcineli Vieira
Published: August 2023

Objective To analyze the impact of the COVID-19 pandemic on the residency of gynecology and obstetrics in São Paulo.

Methods Cross-sectional study developed by representatives of residents of the Association of Gynecology and Obstetrics of the State of São Paulo (SOGESP, in the Portuguese acronym). Data were collected from questionnaires applied to gynecology and obstetrics residents registered on the SOGESP website in February 2022. The interviewees answered about the repercussions of the pandemic on medical residency and whether they had technical and psychological support during the period.

Results A total of 247 questionnaires were collected from residents of gynecology and obstetrics. The residents had an age of 28.3 ± 3 years old, and most of them were female (88.4%). The displacement to COVID care was reported by 62.34% of the students, but only 35.6% reported completely adequate personal protective equipment and only 7.7% reported complete theoretical and technical instruction to support these patients. Almost all of the interviewees stated that the gynecology sector was the most affected. The majority of the interviewees considered that the second-year residents had the greatest loss, and more than half of the residents in the 1st and 2nd year said they wished to give up their residency during the pandemic. More than 80% of the residents reported online theoretical classes and/or presentation of articles, reinforcing the fact that virtual activities gained a greater space within the medical residency.

Conclusion The pandemic impacted the residency in greater proportion in outpatient clinics and gynecological surgeries, also interfering with the physician's desire to continue with the program.
Unleashing the Power of Narratives: Crafting Compelling Homeopathic Case Reports—Part 2 of the Research Method Series
Authors: Dutta Abhijit
Published: August 2023

The case report is an essential genre in medical literature that presents unique clinical observations, findings, and outcomes of an individual patient. In the field of homeopathy, case reports hold significant value as they contribute to the growing body of evidence and provide insights into the extent of effect and applicability of homeopathic treatments in real-world scenarios. This article aims to provide guidance on how to write a comprehensive case report in homeopathy, highlighting key elements such as case selection, data collection, preparation, ethical considerations, and submission. The article emphasizes the importance of accurate and detailed documentation, adherence to reporting guidelines, and the role of case reports in advancing medical knowledge, guiding clinical decision-making, and inspiring further research. Additionally, it addresses the nuances of clinical photography, the de-identification process, and maintaining patient confidentiality. By following the recommended practices outlined in this article, homeopathic practitioners and researchers can effectively contribute to medical literature, enhance their clinical practice, and promote real-word homeopathic care.
Producing safer, more environmentally friendly fire-resistant fabrics
Authors: Shapiro Maura
Published: August 2023

Novel finishing method employs anchor peptides to adhere bio-hybrid fire retardants.
Improved oscillation estimates and the Hitchin–Thorpe inequality on compact Ricci solitons
Authors: Tadano Homare
Published: August 2023

Stimulated by improved oscillation estimates of the potential function and the scalar curvature on compact gradient Ricci solitons introduced in a recent study by Cheng, Ribeiro, and Zhou [Proc. Am. Math. Soc. Ser. B 10, 33–45 (2023)], we give several new sufficient conditions for compact four-dimensional normalized shrinking Ricci solitons to satisfy the Hitchin–Thorpe inequality. Our new conditions refine the validity of the Hitchin–Thorpe inequality obtained by Tadano [J. Math. Phys. 58, 023503 (2017)], Tadano [J. Math. Phys. 59, 043507 (2018)], and Tadano [Differ. Geom. Appl. 66, 231–241 (2019)].
Counter electrode corrosion mechanism in Sn-contained perovskite solar cells
Authors: Zhou Xiaolu , Xing Yanjun , Deng Zhiqiang , Zhao Rui , Huang Jiwen , Li Jiaxin , Xiong Jiaxing , Wang Qiuxiang , Liu Jian , Liu Xiaohui , Huang Like , Hu Ziyang , Zhu Yuejin , Zhang Jing
Published: August 2023

In the recently researched Sn-contained perovskite solar cells (PSCs), limited work is focused on corrosion of a metal electrode, which is recognized as the obstacle of efficient and stable devices. Here, it is found that a pure Sn based PSC shows the most serious and quick corrosion of an Ag electrode, compared with Pb and Sn–Pb PSCs. I2, SnOX, and AgI are the main products of the aged Ag electrode in Sn based PSCs, which greatly differed from Pb and Sn–Pb PSCs. Oxidation of FASnI3 under O2/H2O produces aggressive I2, together with gaseous FA and diffusive I−, degrading the PVK film and Ag electrode greatly. This work highlights the corrosion velocity and mechanism of Ag electrodes in Sn-contained PSCs, which may help to find out possible solutions to circumvent the instable issue.
About the notion of eigenstates for C*-algebras and some application in quantum mechanics
Authors: De Nittis Giuseppe , Polo Ojito Danilo
Published: August 2023

This work is concerned with the notion of eigenstates for C*-algebras. After reviewing some basic and structural results, we explore the possibility of reinterpreting certain typical concepts of quantum mechanics (e.g., dynamical equilibrium states, ground states, gapped states, Fermi surfaces) in terms of (algebraic) eigenstates.
Defect effect of graphene on interface properties of copper/graphene/copper composite: A first-principles study
Authors: He Shiyu , Liu Baishan , Pei Zhongzheng , Zhang Xiaohui , Liu Bin , Xiong Ding-Bang
Published: August 2023

The introduction of defects in graphene will affect the mechanical and electrical properties of the composite interface. We investigate the effect of Stone–Wales (S-W), single-vacancy (S-V), and double-vacancy (D-V) defects on interface properties of copper/graphene/copper (Cu/Gr/Cu) sandwich models using the first-principles study. The results indicate that most defects forming in the Cu/Gr/Cu interface have lower formation energy than that in the free graphene slab. The introduction of defects is beneficial to enhance interface bonding while decreasing electrical properties due to electron scattering. By analyzing the differential charge density of all the Cu/Gr/Cu models with defects, we show that the defects cause changes in electron distribution and facilitate charge transfer between graphene and adjacent copper layers by altering the atomic layer distance.
Determination of diffusivities in binary fluid mixtures with various Lewis numbers as well as positive and negative Soret coefficients by the shadowgraph method
Authors: Wu W. , Schmidt P. S. , Piszko M. , Giraudet C. , Rausch M. H. , Fröba A. P.
Published: August 2023

The present work demonstrates the accessibility of the Fick diffusion coefficient D11 and/or the thermal diffusivity a of the binary mixtures dicyclohexylmethane/diphenylmethane, n-hexane/carbon dioxide, 1-hexanol/carbon dioxide, and methane/propane by the analysis of the dynamics of non-equilibrium fluctuations using the shadowgraph method. It is evidenced that D11 and a can be simultaneously determined for binary mixtures with Lewis numbers Le = a/D11 ranging over two orders of magnitude down to Le ≈ 5 or in the presence of minor advection for binary mixtures possessing a negative Soret coefficient in the investigated temperature and pressure ranges from (298.15 to 473.15) K and from about (0.5 to 25) MPa. The determined diffusivities are compared with those measured by heterodyne dynamic light scattering or obtained from the literature, with a focus on achievable uncertainties. By this comparison, it is shown that the determination of a by the shadowgraph method was hindered by mode-coupling effects for Le ≈ 5, whereas a determination of D11 was always possible for mixtures with Le ≥ 5. Furthermore, it is demonstrated that even in the presence of solutal advection, the description of the purely diffusive behavior of non-equilibrium fluctuations in concentration remains valid.
Numerical modeling of the long surface wave impact on a partially immersed structure in a coastal zone: Solitary waves over a flat slope
Authors: Gusev O. I. , Khakimzyanov G. S. , Skiba V. S. , Chubarov L. B.
Published: August 2023

This paper describes the numerical simulation of the solitary wave impact on a partially immersed and fixed structure located over a flat coastal slope. This topic is related to the need for assessment of the possible impact of long waves, such as tsunamis, on partially immersed structures in coastal waters. Numerical algorithms on a movable grid adapting to the motion of the shore point are developed for a fully nonlinear dispersive model and a dispersionless shallow water model. Their validation is carried out by comparing the obtained solutions with the data from laboratory experiments and with the results obtained using a fully nonlinear potential flow model. The study shows that the difference between the maximum wave impact on the body at the foot of the slope and near the shore can be up to 6 times. In many cases, the maximum horizontal component of the wave force occurs under the influence of the wave reflected from the shore, indicating the need to consider the influence of the shore-reflected wave when assessing the impact of long waves on structures located in coastal waters. Furthermore, the need to use runup algorithms instead of reflective boundary conditions (vertical wall) has been identified for gentler slopes, where the differences in the wave impact for these two configurations can be 2–3 times.
An accurate and efficient fragmentation approach via the generalized many-body expansion for density matrices
Authors: Ballesteros Francisco , Tan Jake A. , Lao Ka Un
Published: August 2023

With relevant chemical space growing larger and larger by the day, the ability to extend computational tractability over that larger space is of paramount importance in virtually all fields of science. The solution we aim to provide here for this issue is in the form of the generalized many-body expansion for building density matrices (GMBE-DM) based on the set-theoretical derivation with overlapping fragments, through which the energy can be obtained by a single Fock build. In combination with the purification scheme and the truncation at the one-body level, the DM-based GMBE(1)-DM-P approach shows both highly accurate absolute and relative energies for medium-to-large size water clusters with about an order of magnitude better than the corresponding energy-based GMBE(1) scheme. Simultaneously, GMBE(1)-DM-P is about an order of magnitude faster than the previously proposed MBE-DM scheme [F. Ballesteros and K. U. Lao, J. Chem. Theory Comput. 18, 179 (2022)] and is even faster than a supersystem calculation without significant parallelization to rescue the fragmentation method. For even more challenging systems including ion–water and ion–pair clusters, GMBE(1)-DM-P also performs about 3 and 30 times better than the energy-based GMBE(1) approach, respectively. In addition, this work provides the first overlapping fragmentation algorithm with a robust and effective binning scheme implemented internally in a popular quantum chemistry software package. Thus, GMBE(1)-DM-P opens a new door to accurately and efficiently describe noncovalent clusters using quantum mechanics.