bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoscale Structure and Dynamics of Model Membrane Lipid Raft Systems, Studied by Neutron Scattering Methods
Authors: Ahmadi Delaram , Thompson Katherine C. , García Sakai Victoria , Schweins Ralf , Moulin Martine , Haertlein Michael , Strohmeier Gernot A. , Pichler Harald , Forsyth V. Trevor , Barlow David J. , Lawrence M. Jayne , Foglia Fabrizia 
Published: April 2022

Quasi-elastic neutron scattering (QENS) and small angle neutron scattering (SANS), in combination with isotopic contrast variation, have been used to determine the structure and dynamics of three-component lipid membranes, in the form of vesicles, comprising an unsaturated [palmitoyl-oleoyl-phosphatidylcholine (POPC) or dioleoyl-phosphatidylcholine (DOPC)], a saturated phospholipid (dipalmitoyl-phosphatidylcholine (DPPC)), and cholesterol, as a function temperature and composition. SANS studies showed vesicle membranes composed of a 1:1:1 molar ratio of DPPC:DOPC:cholesterol and a 2:2:1 molar ratio of DPPC:POPC:cholesterol phase separated, forming lipid rafts of ∼18 and ∼7 nm diameter respectively, when decreasing temperature from 308 to 297 K. Phase separation was reversible upon increasing temperature. The larger rafts observed in systems containing DOPC are attributed to the greater mis-match in lipid alkyl chains between DOPC and DPPC, than for POPC and DPPC. QENS studies, over the temperature range 283–323K, showed that the resulting data were best modelled by two Lorentzian functions: a narrow component, describing the “in-plane” lipid diffusion, and a broader component, describing the lipid alkyl chain segmental relaxation. The overall “in-plane” diffusion was found to show a significant reduction upon increasing temperature due to the vesicle membranes transitioning from one containing rafts to one where the component lipids are homogeneously mixed. The use of different isotopic combinations allowed the measured overall reduction of in-plane diffusion to be understood in terms of an increase in diffusion of the saturated DPPC lipid and a corresponding decrease in diffusion of the unsaturated DOPC/POPC lipid. As the rafts are considered to be composed principally of saturated lipid and cholesterol, the breakdown of rafts decreases the exposure of the DPPC to cholesterol whilst increasing the exposure of cholesterol to unsaturated lipid. These results show the sensitivity of lipid diffusion to local cholesterol concentration, and the importance of considering the local, rather that the global composition of a membrane when understanding the diffusion processes of lipids within the membrane. The novel combination of SANS and QENS allows a non-intrusive approach to characterize the structure and dynamics occurring in phase-separated model membranes which are designed to mimic the lateral heterogeneity of lipids seen in cellular membranes–a heterogeneity that can have pathological consequences.
What Can We Learn from Single Sarcomere and Myofibril Preparations?
Authors: Herzog Walter 
Published: April 2022

Sarcomeres are the smallest functional contractile unit of muscle, and myofibrils are striated muscle organelles that are comprised of sarcomeres that are strictly aligned in series. Furthermore, passive forces in sarcomeres and myofibrils are almost exclusively produced by the structural protein titin, and all contractile, regulatory, and structural proteins are in their natural configuration. For these mechanical and structural reasons single sarcomere and myofibril preparations are arguably the most powerful to answer questions on the mechanisms of striated muscle contraction. We developed and optimized single myofibril research over the past 20 years and were the first to mechanically isolate and test single sarcomeres. The results from this research led to the uncovering of the crucial role of titin in muscle contraction, first molecular explanations for the origins of the passive and the residual force enhancement properties of skeletal and cardiac muscles, the discovery of sarcomere length stability on the descending limb of the force-length relationship, and culminating in the formulation of the three-filament theory of muscle contraction that, aside from actin and myosin, proposes a crucial role of titin in active force production. Aside from all the advantages and possibilities that single sarcomere and myofibril preparations offer, there are also disadvantages. These include the fragility of the preparation, the time-consuming training to master these preparations, the limited spatial resolution for length and force measurements, and the unavailability of commercial systems for single sarcomere/myofibril research. Ignoring the mechanics that govern serially linked systems, not considering the spatial resolution and associated accuracies of myofibril systems, and neglecting the fragility of myofibril preparations, has led to erroneous interpretations of results and misleading conclusions. Here, we will attempt to describe the methods and possible applications of single sarcomere/myofibril research and discuss the advantages and disadvantages by focusing on specific applications. It is hoped that this discussion may contribute to identifying the enormous potential of single sarcomere/myofibril research in discovering the secrets of muscle contraction.
Understanding the Role of Propulsion in the Prediction of Front-Crawl Swimming Velocity and in the Relationship Between Stroke Frequency and Stroke Length
Authors: Morais Jorge E. , Barbosa Tiago M. , Nevill Alan M. , Cobley Stephen , Marinho Daniel A. 
Published: April 2022

Introduction: This study aimed to: 1) determine swimming velocity based on a set of anthropometric, kinematic, and kinetic variables, and; 2) understand the stroke frequency (SF)–stroke length (SL) combinations associated with swimming velocity and propulsion in young sprint swimmers.Methods: 38 swimmers (22 males: 15.92 ± 0.75 years; 16 females: 14.99 ± 1.06 years) participated and underwent anthropometric, kinematic, and kinetic variables assessment. Exploratory associations between SL and SF on swimming velocity were explored using two two-way ANOVA (independent for males and females). Swimming velocity was determined using multilevel modeling.Results: The prediction of swimming velocity revealed a significant sex effect. Height, underwater stroke time, and mean propulsion of the dominant limb were predictors of swimming velocity. For both sexes, swimming velocity suggested that SL presented a significant variation (males: F = 8.20, p &lt; 0.001, η2 = 0.40; females: F = 18.23, p &lt; 0.001, η2 = 0.39), as well as SF (males: F = 38.20, p &lt; 0.001, η2 = 0.47; females: F = 83.04, p &lt; 0.001, η2 = 0.51). The interaction between SL and SF was significant for females (F = 8.00, p = 0.001, η2 = 0.05), but not for males (F = 1.60, p = 0.172, η2 = 0.04). The optimal SF–SL combination suggested a SF of 0.80 Hz and a SL of 2.20 m (swimming velocity: 1.75 m s−1), and a SF of 0.80 Hz and a SL of 1.90 m (swimming velocity: 1.56 m s−1) for males and females, respectively. The propulsion in both sexes showed the same trend in SL, but not in SF (i.e., non-significant variation). Also, a non-significant interaction between SL and SF was observed (males: F = 0.77, p = 0.601, η2 = 0.05; females: F = 1.48, p = 0.242, η2 = 0.05).Conclusion: Swimming velocity was predicted by an interaction of anthropometrics, kinematics, and kinetics. Faster velocities in young sprinters of both sexes were achieved by an optimal combination of SF–SL. The same trend was shown by the propulsion data. The highest propulsion was not necessarily associated with higher velocity achievement.
Search for Venous Endothelial Biomarkers Heralding Venous Thromboembolism in Space: A Qualitative Systematic Review of Terrestrial Studies
Authors: Harris Katie , Laws Jonathan Michael , Elias Antoine , Green David Andrew , Goswami Nandu , Jordan Jens , Kamine Tovy Haber , Mazzolai Lucia , Petersen Lonnie G. , Winnard Andrew James , Weber Tobias 
Published: April 2022

Background: The recent discovery of a venous thrombosis in the internal jugular vein of an astronaut has highlighted the need to predict the risk of venous thromboembolism in otherwise healthy individuals (VTE) in space. Virchow’s triad defines the three classic risk factors for VTE: blood stasis, hypercoagulability, and endothelial disruption/dysfunction. Among these risk factors, venous endothelial disruption/dysfunction remains incompletely understood, making it difficult to accurately predict risk, set up relevant prophylactic measures and initiate timely treatment of VTE, especially in an extreme environment.Methods: A qualitative systematic review focused on endothelial disruption/dysfunction was conducted following the guidelines produced by the Space Biomedicine Systematic Review Group, which are based on Cochrane review guidelines. We aimed to assess the venous endothelial biochemical and imaging markers that may predict increased risk of VTE during spaceflight by surveying the existing knowledge base surrounding these markers in analogous populations to astronauts on the ground.Results: Limited imaging markers related to endothelial dysfunction that were outside the bounds of routine clinical practice were identified. While multiple potential biomarkers were identified that may provide insight into the etiology of endothelial dysfunction and its link to future VTE, insufficient prospective evidence is available to formally recommend screening potential astronauts or healthy patients with any currently available novel biomarker.Conclusion: Our review highlights a critical knowledge gap regarding the role biomarkers of venous endothelial disruption have in predicting and identifying VTE. Future population-based prospective studies are required to link potential risk factors and biomarkers for venous endothelial dysfunction to occurrence of VTE.
The Impact of Early Neighborhood Cohesion, and Its Mechanism, on Cognitive Function in Later Life
Authors: Zhou Tao , Zhang Xiaoyi , Fan Shuming , Deng Zeming , Jiao Can 
Published: April 2022

ObjectivesThis study aimed to explore the impact of early neighborhood cohesion, and its mechanism, on cognitive function in later life.MethodsIn total, 10,727 Chinese elderly, aged 60–90, forming two datasets (2014 and 2018) from the China Health and Retirement Longitudinal Study (CHARLS) were used as a sample. Childhood neighborhood cohesion was measured by the extent of how much neighbors were willing to help and how close-knit neighbors were. Mini-Mental State Examination (MMSE) and Center for Epidemiologic Studies Depression Scale (CESD-10) were used to assess the cognitive functions and depression of the elderly. We used a structural equation model to examine the relationship between early neighborhood cohesion and late-life cognitive function and conducted bootstrapping analyses to assess the mechanism.ResultsCognitive function was positively predicted by childhood neighborhood cohesion (β = 0.06, p &lt; 0.001), and cognitive function of the elderly were also positively predicted through the mediating effects of childhood friendships, which included depression and social activity participation as two chain paths.ConclusionThe findings suggest that childhood neighborhood cohesion positively predicts cognitive function among elderly people through the mediating roles of childhood friendship, depression, and social activity engagement. Childhood neighborhood cohesion is correlated with better childhood friendships, then to fewer depression symptoms and greater elderly social activity participation, and finally to better cognitive functions in the elderly.
Gender Differences in Job Burnout, Career Choice Regret, and Depressive Symptoms Among Chinese Dental Postgraduates: A Cross-Sectional Study
Authors: Yan Li , Zhong Xiaogang , Yang Lu , Long Huiqing , Ji Ping , Jin Xin , Liu Li 
Published: April 2022

BackgroundJob burnout, career choice regret, and depressive symptoms among medical students have received widespread attention. However, little is known about the role of gender in these areas for dental postgraduates. This study aimed to explore gender differences in job burnout, career choice regret, and depressive symptoms among Chinese dental postgraduates.MethodsThe data were collected from an epidemiological survey conducted by our group from February 2021 to March 2021. We used a self-administered questionnaire covering demographic characteristics, the Maslach Burnout Inventory, the Primary Care Evaluation of Mental Disorders scale, and the Career Choice Regret scale. Univariate and multivariable analyses were performed to explore influencing factors.ResultsA total of 558 valid dental postgraduate questionnaires were included in this study. The prevalence of job burnout, career choice regret, and depressive symptoms exceeded 30% in males and females. The prevalence of job burnout was 4.7% higher in females than in males; career choice regret was 12.2% higher in females than in males (P &lt; 0.05), and depressive symptoms were 4.9% higher in females than in males. The multivariable analysis showed that factors associated with job burnout for males were sleep time and career choice regret for females. The influencing factors on career choice regret for females were postgraduate entrance examination score, sleep time, and job burnout. Depressive symptoms were a common influencing factor for job burnout and career choice regret in male and female dental postgraduates. Also, job burnout and depressive symptoms had the highest odds ratio for influencing factors on each other.ConclusionOver 30% of dental postgraduates suffered from job burnout, career choice regret, and depressive symptoms, and incidences were higher in females. A discrepancy of influencing factors existed between male and female dental postgraduates. Targeted measures should be taken to change this situation.
Cost-Effectiveness of Avelumab Maintenance Therapy Plus Best Supportive Care vs. Best Supportive Care Alone for Advanced or Metastatic Urothelial Carcinoma
Authors: Xie Qian , Zheng Hanrui , Chen Ye , Peng Xingchen 
Published: April 2022

ObjectiveAvelumab (MSB0010718C) is a fully human anti-programmed cell death ligand 1(PD-L1) antibody against PD-L1 interactions and enhances immune activation against tumor cells in the meantime. Avelumab has been approved for locally advanced or metastatic urothelial cancer (mUC) after disease progression in several countries. We therefore conducted this study to evaluate the cost-effectiveness of avelumab maintenance therapy for advanced or mUC from the perspective of the United States (US) and China payer.MethodsA Markov simulation model was performed based on clinical trial JAVELIN Bladder 100. Utilities and costs adopted in this analysis were derived from published literature and clinical trials. Incremental cost-effectiveness ratios (ICERs) were calculated to compare the avelumab maintenance therapy group (AVE group) and the best supportive care group (CON group).ResultsThe ICER of the AVE group compared with the CON group were $38,369.50 and $16,150.29 per QALYs in the overall population and in the PD-L1–positive population, respectively. While the ICER of AVE group compared with CON group were $241,610.25 and $100,528.29 per QALYs in the overall population and in the PD-L1–positive population, respectively.ConclusionAvelumab maintenance therapy was a cost-effective first-line treatment compared with BSC in patients with mUC which were not progressed with platinum-based chemotherapy not only in the PD-L1–positive population but also in the overall population based on the current willingness to pay (WTP) of $150,000 in the US. It was not cost-effective both in the overall population and in the PD-L1 positive population at the WTP threshold of $30,447.09 in China.
Occupational Burnout Symptoms and Its Relationship With Workload and Fear of the SARS-CoV-2 Pandemic Among Hospital Nurses
Authors: Belji Kangarlou Marzieh , Fatemi Farin , Paknazar Fatemeh , Dehdashti Alireza 
Published: April 2022

IntroductionThe pandemic has intensified physical and psychological work demands experienced by nurses in a hospital environment. The purpose of this study was to examine personal and work environmental risk factors associated with occupational burnout among hospital nurses.MethodsWe conducted a cross-sectional from April to November 2020. Data from 831 nurses who worked professionally in four educational hospitals were compiled through survey questionnaires to report the prevalence of burnout, occupational and individual factors. Independent t-test and Mann–Whitney test measured the link between the scopes of occupational burnout and risk factors.ResultsAbout half of the participants indicated moderate symptoms of burnout. The fear of the nurses correlated significantly with emotional exhaustion (r = 0.71, p = 0.001), depersonalization (r = 0.67, p = 0.02), and personal accomplishment (r = 0.63, p = 0.05). Mental demand (r = 0.74, p = 0.01) and effort at work (r = 0.68, 0.001) correlated significantly with emotional exhaustion (r = 0.51, p = 0.03).ConclusionThe findings indicated a high prevalence of burnout symptoms, particularly emotional exhaustion, among hospital nursing professionals. Occupational health services should consider burnout as an occupational-related condition and provide interventions to reduce workplace chronic stressors and burnout in hospitals.
The Moderating Effect of Community Environment on the Association Between Social Support and Chinese Older Adults' Health: An Empirical Analysis Study
Authors: Li Dongfang , Li Xiaolin , Zeng Yi 
Published: April 2022

BackgroundThe aging population conundrum and the gradual weakening of older adults' health and ability to obtain resources as they age have drawn attention to this population's health. Older adults' health relates not only to their own quality of life, but also to the development of families/society.MethodsWe analyzed micro data from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study Follow-up Questionnaire, using the probit model, ordinary least squares model, and other methods.Results and ConclusionsBoth formal and informal social support significantly impacted the physical and mental health of Chinese older adults, and the community environment moderated this relationship. To build a reasonable and effective social support system for older adults and improve their health, we suggest that stakeholders should continue to strengthen the formal and informal social support provided to older adults; they should also build a community-based care system, which will allow for the moderating role of community environment on the relationship between social support and older adults' health. Family and social support factors are important for older adults' health. We should enable the moderating role of community environment on the relationship between social support and health to be fully exerted, as well as build a community-based pension system.
Effect of Fatiguing Wheelchair Propulsion and Weight Relief Lifts on Subacromial Space in Wheelchair Users
Authors: Arnet Ursina , Boninger Michael L. , Cools Ann , Bossuyt Fransiska M. 
Published: April 2022

ObjectiveThis study aimed to identify targets of intervention for reducing shoulder pain in wheelchair users with spinal cord injury (SCI) by (1) examining changes in subacromial space [acromiohumeral distance (AHD) and occupation ratio (OccRatio)] with fatiguing wheelchair propulsion, and different loading conditions [unloaded position vs. weight relief lifts (WRL)]; (2) associating these changes with wheelchair user capacity, as well as (3) identifying subject characteristics associated with subacromial space, such as sex, lesion level, time since injury, body mass index and impaired shoulder range of motion.MethodsFifty manual wheelchair users with SCI [11 females, age = 50.5 (9.7) years, time since injury = 26.2 (11.4) years] participated in this quasi-experimental one-group pretest-posttest study. Ultrasound images were used to define AHD during an unloaded position, and during personal and instructed WRL before and after fatiguing wheelchair propulsion. Furthermore, supraspinatus and biceps thickness defined from ultrasound images were used to calculate OccRatios. Wheelchair user capacity was quantified as functional strength (maximum resultant force reached during maximum isometric forward push) and anaerobic work capacity (highest power output reached during 15-m sprint test). Multilevel mixed-effects linear regression analyses controlling for between subject variability and covariables were performed to address the research questions.ResultsAHD was significantly smaller during personal WRL (p &lt; 0.001) and instructed WRL (p = 0.009, AHD both 11.5 mm) compared to the unloaded position (11.9 mm). A higher wheelchair user capacity (higher anaerobic work capacity) reduced the impact of WRL on AHD decrease. The fatiguing wheelchair propulsion had no effect on AHD (p = 0.570) and on OccRatio of supraspinatus (p = 0.404) and biceps (p = 0.448). Subject characteristics related to a larger subacromial space were lower lesion level, shorter time since injury, impaired external rotation, a lower body mass index and a higher anaerobic work capacity.ConclusionThis study showed a significant reduction in AHD during WRL with no effect of fatiguing wheelchair propulsion on the subacromial space in wheelchair users with SCI. A higher anaerobic work capacity was beneficial in stabilizing the shoulder during WRL. Our findings may assist clinicians in designing a shoulder injury prevention program.
As-Sintered Manganese-Stabilized Zirconia Ceramics with Excellent Electrical Conductivity
Authors: Gao Ling , Guan Ruidong , Zhang Shengnan , Zhi Hao , Jin Changqing , Jin Lihua , Wei Yongxing , Wang Jianping 
Published: April 2022

As promising electrolyte materials in intermediate-temperature solid oxide fuel cells (IT-SOFCs), Sc-stabilized ZrO2 (ScSZ) and Y-stabilized ZrO2 (YSZ) electrolytes continue to be plagued by high cost and low intermediate conductivity. To mitigate these problems, Mn has been chosen as a new stabilization element for the synthesis of Mn-stabilized ZrO2 ceramics (MnSZ) through solid state sintering. Microstructures and electrical properties of micron-crystalline Zr1−xMnxO2−δ (x = 0.15, 0.20 and 0.25) ceramics electrolytes for IT-SOFCs have been systematically evaluated. Within the applied doping content, Mn2+ ions can enter the ZrO2 crystal lattice, leading to the formation of single cubic phase samples. Electrical conductivity measurements in the temperature range between 400 °C and 1000 °C show a sharp increase in conductivity due to Mn doping. The highest conductivity is obtained from the Zr0.75Mn0.25O2−δ samples, being 0.0144 S/cm at 600 °C and 0.182 S/cm at 1000 °C. The electrical conductivity at 600 °C is twice higher than that of the YSZ and two orders of magnitude higher than that of the ScSZ. These properties can fulfill the conductivity requirement (∼1 × 10−2 S/cm) for the electrolyte. Therefore, based on this study, we propose that Mn stabilized ZrO2 is a promising candidate as a solid electrolyte for IT-SOFCs.