Sprint Variables Are Associated with the Odds Ratios of Non-Contact Injuries in Professional Soccer Players

Significant evidence has emerged that a high volume of sprinting during training is associated with an increased risk of non-contact injuries in professional soccer players. Training load has been reported as a modifiable risk factor for successive injury in soccer. Sprint workload measures and non-contact injuries were recorded weekly in twenty-one professional soccer players over a one season period. Odds ratio (OR) and relative risk (RR) were calculated based on the weeks of high and low load of total distance (TD), high-speed distance (HSD), sprint distance (SPD). and repeated sprints (RS). The Poisson distribution estimated the interval time between the last injury and the new injury. The weeks with high-load levels increased the risk of non-contact injury associated with TD (OR: 4.1; RR: 2.4), HSD (OR: 4.6; RR: 2.6), SPD (OR: 6.9; RR: 3.7), and RS (OR: 4.3; RR: 2.7). The time between injuries was significantly longer in weeks of low-load in TD (rate ratio time (RRT) 1.5 vs. 4.2), HSD (RRT: 1.6 vs. 4.6), and SPD (RRT: 1.7 vs. 7.7) compared to weeks of high-load. The findings highlight an increased risk of non-contact injuries during high weekly sprint workloads. Possibly, TD, HSD, and SPD measured via a wearable inertial measurement unit could be modeled to track training and to reduce non-contact injuries. Finally, the interval time between the last injury and the new injury at the high-load is shorter than the low-load

Somatotype, accumulated workload, and fitness parameters in elite youth players: associations with playing position

The purpose of this study was three-fold: (1) to describe anthropometric, maturation, and somatotype differences of players based on playing positions; (2) to analyze variations of accumulated load training (AcL) and fitness parameters between playing positions; and finally (3) to explain the variation of maximal oxygen uptake (VO2max) and peak power (PP) through the AcL, body fat (BF), maturity, somatotype and fitness levels. Twenty-seven male youth soccer players under-16 were divided by the following positions participated in this study: six central midfielders, four wingers (WG), five forwards, eight defenders, and four goalkeepers (GK). They were evaluated on two occasions: pre-season and after-season. Height, sitting height, body mass, BF, girths, percentage of BF (BF%), lean body mass, maturity, somatotype, sprint test, change of direction test, Yo-Yo intermittent recovery test level 1, Wingate, PP, VO2max and fatigue index were assessed. Then, AcL was monitored during training sessions. The main results revealed significant differences between player positions for maturity offset (p = 0.001), for BF (p = 0.006), BF% (p = 0.015), and lean body mass kg (p = 0.003). Also, there were significant differences for AcL and fatigue index in pre-season between player positions (p < 0.05). In addition, there were some significant differences in pre- and after-season for VO2max and PP between player positions (p < 0.05). In conclusion, GK showed higher values in anthropometric, body composition variables and maturity offset compared to the other positions, while WG presented lower levels of BF. In pre-season, there were more differences by player positions for the different variables analyzed than after-season that reinforces the tactical role of the positions, and the emphasis in increased load in the beginning of the season. This study could be used by coaches, staff, and researchers as a reference for athletes of the same sex, age, and competitive level

Thermal Stability of the Human Immunodeficiency Virus Type 1 (HIV-1) Receptors, CD4 and CXCR4, Reconstituted in Proteoliposomes

BACKGROUND: The entry of human immunodeficiency virus (HIV-1) into host cells involves the interaction of the viral exterior envelope glycoprotein, gp120, and receptors on the target cell. The HIV-1 receptors are CD4 and one of two chemokine receptors, CCR5 or CXCR4. METHODOLOGY/PRINCIPAL FINDINGS: We created proteoliposomes that contain CD4, the primary HIV-1 receptor, and one of the coreceptors, CXCR4. Antibodies against CD4 and CXCR4 specifically bound the proteoliposomes. CXCL12, the natural ligand for CXCR4, and the small-molecule CXCR4 antagonist, AMD3100, bound the proteoliposomes with affinities close to those associated with the binding of these molecules to cells expressing CXCR4 and CD4. The HIV-1 gp120 exterior envelope glycoprotein bound tightly to proteoliposomes expressing only CD4 and, in the presence of soluble CD4, bound weakly to proteoliposomes expressing only CXCR4. The thermal stability of CD4 and CXCR4 inserted into liposomes was examined. Thermal denaturation of CXCR4 followed second-order kinetics, with an activation energy (E(a)) of 269 kJ/mol (64.3 kcal/mol) and an inactivation temperature (T(i)) of 56°C. Thermal inactivation of CD4 exhibited a reaction order of 1.3, an E(a) of 278 kJ/mol (66.5 kcal/mol), and a T(i) of 52.2°C. The second-order denaturation kinetics of CXCR4 is unusual among G protein-coupled receptors, and may result from dimeric interactions between CXCR4 molecules. CONCLUSIONS/SIGNIFICANCE: Our studies with proteoliposomes containing the native HIV-1 receptors allowed an examination of the binding of biologically important ligands and revealed the higher-order denaturation kinetics of these receptors. CD4/CXCR4-proteoliposomes may be useful for the study of virus-target cell interactions and for the identification of inhibitors

Development of a Novel Low-Cost Exoscope to Expand Access to Microneurosurgical Care in Low- and Middle-Income Countries

Background: Less than a quarter of the world population has access to microneurosurgical care within a range of 2 hours. We introduce a simplified exoscope system to achieve magnification, illumination, and video recording in low-resource settings. Methods: We combined an industrial microscope tube, a heavy-duty support arm, a wide-field c-mount digital microscope camera, and a light-emitting diode ring light. All parts were sterilized with ethylene oxide. We performed 13 spinal and 3 cranial surgeries with the help of the low-budget exoscope. Results: The average preoperative setup time was 12.8 minutes. The exoscope provided similar magnification and illumination like a conventional binocular microscope. It allowed operating in a comfortable posture. The field of vision ranged from 30 mm–60 mm. The surgical field was captured by a 16-megapixel two-dimensional camera and projected to a 55-inch high-definition television screen in real time. Image quality was similar to that of a conventional microscope although our exoscope lacked stereoscopic view. Adjusting camera position and angle was time-consuming. Thus, the benefit of the exoscope was most notable in spine surgeries where the camera remained static for most of the time. The total cost of the exoscope was approximately U.S. $ 750. Conclusions: Our low-budget exoscope offers similar image quality, magnification, and illumination like a conventional binocular microscope. It may thus help expand access to neurosurgical care worldwide. Users may face difficulty adapting to the lack of depth perception in the beginning. Prospective studies are needed to assess its usability and effectiveness compared to the microscope. © 2022 Elsevier Inc

Evaluating community-based participatory research to improve community-partnered science and community health

Community-based participatory research; community health research; health disparities; process issues Background: Since 2007, the National Congress of American Indians (NCAI) Policy Research Center (PRC) has partnered with the Universities of New Mexico and Washington to study the science of community-based participatory research (CBPR). Our goal is to identify facilitators and barriers to effective community academic partnerships in American Indian and other communities, which face health disparities. Objectives: We have described herein the scientific design of our National Institutes of Health (NIH)-funded study (2009-2013) and lessons learned by having a strong community partner leading the research efforts. Methods: The research team is implementing a mixed-methods study involving a survey of principal investigators (PIs) and partners across the nation and in-depth case studies of CBPR projects. Results: We present preliminary findings on methods and measures for community-engaged research and eight lessons learned thus far regarding partnership evaluation, advisory councils, historical trust, research capacity development of community partner, advocacy, honoring each other, messaging, and finding. Conclusions: Study methodologies and lessons learned can help community academic research partnerships translate research in communities