Exploring how arm movement moderates the effect of lower limb muscle fatigue on dynamic balance in healthy youth.

Background: In young adults, there is evidence that free arm movements do not help to compensate muscle fatigue-induced deteriorations in dynamic balance performance. However, the postural control system in youth is immature, and as a result, the use of arm movements may provide a compensatory "upper body strategy" to correct fatigue-related balance impairments. Thus, the purpose of the present study was to compare the effects of free vs. restricted arm movement on dynamic balance performance prior and following exercise-induced muscle fatigue. Methods: Forty-three healthy youth (19 females; mean age: 12.8 ± 1.9 years) performed the Y Balance Test-Lower Quarter before and immediately after a fatiguing exercise (i.e., repetitive vertical bipedal box jumps until failure) using two different arm positions: free (move the arms freely) and restricted (keep the arms akimbo) arm movement. Results: Muscle fatigue (p ≤ 0.033; 0.10 ≤ η p 2 ≤ 0.33) and restriction of arm movement (p ≤ 0.005; 0.17 ≤ η p 2 ≤ 0.46) resulted in significantly deteriorated dynamic balance performance. However, the interactions between the two did not reach the level of significance (p ≥ 0.091; 0.01 ≤ η p 2 ≤ 0.07). Conclusion: Our findings indicate that the use of an "upper body strategy" (i.e., free arm position) has no compensatory effect on muscle fatigue-induced dynamic balance deteriorations in healthy youth.

Kinetic Referencing Allows Identification of Epigenetic Cytosine Modifications by Single-Molecule Hybridization Kinetics and Superresolution DNA-PAINT Microscopy.

We develop a DNA origami-based internal kinetic referencing system with a colocalized reference and target molecule to provide increased sensitivity and robustness for transient binding kinetics. To showcase this, we investigate the subtle changes in binding strength of DNA oligonucleotide hybrids induced by cytosine modifications. These cytosine modifications, especially 5-methylcytosine but also its oxidized derivatives, have been increasingly studied in the context of epigenetics. Recently revealed correlations of epigenetic modifications and disease also render them interesting biomarkers for early diagnosis. Internal kinetic referencing allows us to probe and compare the influence of the different epigenetic cytosine modifications on the strengths of 7-nucleotide long DNA hybrids with one or two modified nucleotides by single-molecule imaging of their transient binding, revealing subtle differences in binding times. Interestingly, the influence of epigenetic modifications depends on their position in the DNA strand, and in the case of two modifications, effects are additive. The sensitivity of the assay indicates its potential for the direct detection of epigenetic disease markers.

Single fibre cytoarchitecture in ventilator-induced diaphragm dysfunction (VIDD) assessed by quantitative morphometry second harmonic generation imaging: Positive effects of BGP-15 chaperone co-inducer and VBP-15 dissociative corticosteroid treatment.

Ventilator-induced diaphragm dysfunction (VIDD) is a common sequela of intensive care unit (ICU) treatment requiring mechanical ventilation (MV) and neuromuscular blockade (NMBA). It is characterised by diaphragm weakness, prolonged respirator weaning and adverse outcomes. Dissociative glucocorticoids (e.g., vamorolone, VBP-15) and chaperone co-inducers (e.g., BGP-15) previously showed positive effects in an ICU-rat model. In limb muscle critical illness myopathy, preferential myosin loss prevails, while myofibrillar protein post-translational modifications are more dominant in VIDD. It is not known whether the marked decline in specific force (force normalised to cross-sectional area) is a pure consequence of altered contractility signaling or whether diaphragm weakness also has a structural correlate through sterical remodeling of myofibrillar cytoarchitecture, how quickly it develops, and to which extent VBP-15 or BGP-15 may specifically recover myofibrillar geometry. To address these questions, we performed label-free multiphoton Second Harmonic Generation (SHG) imaging followed by quantitative morphometry in single diaphragm muscle fibres from healthy rats subjected to five or 10 days of MV + NMBA to simulate ICU treatment without underlying confounding pathology (like sepsis). Rats received daily treatment of either Prednisolone, VBP-15, BGP-15 or none. Myosin-II SHG signal intensities, fibre diameters (FD) as well as the parameters of myofibrillar angular parallelism (cosine angle sum, CAS) and in-register of adjacent myofibrils (Vernier density, VD) were computed from SHG images. ICU treatment caused a decline in FD at day 10 as well as a significant decline in CAS and VD from day 5. Vamorolone effectively recovered FD at day 10, while BGP-15 was more effective at day 5. BGP-15 was more effective than VBP-15 in recovering CAS at day 10 although not to control levels. In-register VD levels were restored at day 10 by both compounds. Our study is the first to provide quantitative insights into VIDD-related myofibrillar remodeling unravelled by SHG imaging, suggesting that both VBP-15 and BGP-15 can effectively ameliorate the structure-related dysfunction in VIDD.

Partner, Neighbor, Housekeeper and Dimension: 3D versus 2D Glomerular Co-Cultures Reveal Drawbacks of Currently Used Cell Culture Models.

Signaling-pathway analyses and the investigation of gene responses to different stimuli are usually performed in 2D monocultures. However, within the glomerulus, cells grow in 3D and are involved in direct and paracrine interactions with different glomerular cell types. Thus, the results from 2D monoculture experiments must be taken with caution. We cultured glomerular endothelial cells, podocytes and mesangial cells in 2D/3D monocultures and 2D/3D co-cultures and analyzed cell survival, self-assembly, gene expression, cell-cell interaction, and gene pathways using live/dead assay, time-lapse analysis, bulk-RNA sequencing, qPCR, and immunofluorescence staining. Without any need for scaffolds, 3D glomerular co-cultures self-organized into spheroids. Podocyte- and glomerular endothelial cell-specific markers and the extracellular matrix were increased in 3D co-cultures compared to 2D co-cultures. Housekeeping genes must be chosen wisely, as many genes used for the normalization of gene expression were themselves affected in 3D culture conditions. The transport of podocyte-derived VEGFA to glomerular endothelial cells confirmed intercellular crosstalk in the 3D co-culture models. The enhanced expression of genes important for glomerular function in 3D, compared to 2D, questions the reliability of currently used 2D monocultures. Hence, glomerular 3D co-cultures might be more suitable in the study of intercellular communication, disease modelling and drug screening ex vivo.

Assessment of Cell Viability in Electrically Excitable Muscle Cells Through Intact Twitch Stimulation.

Muscle cells (i.e. skeletal muscle fibers) are fully viable and functional when their excitation-contraction (EC) coupling machinery is intact. This involves intact membrane integrity with polarized membrane, functional ion channels for action potential generation and conduction, an intact electro-chemical interface at the level of the fiber's triad, followed by sarcoplasmic reticulum Ca2+ release, and subsequent activation of the chemico-mechanical interface at the level of the contractile apparatus. The ultimate end result is then a visible twitch contraction upon a brief electrical pulse stimulation. For many biomedical studies involving single muscle cells, intact and viable myofibers are of utmost importance. Thus, a simple global screening method that involves a brief electrical stimulus applied to single muscle fibers and assessment of visible contraction would be of high value. In this chapter, we describe step-by-step protocols to (i) obtain intact single muscle fibers from freshly dissected muscle tissue using an enzymatic digestion procedure and (ii) provide a workflow for the assessment of twitch response of single fibers that can be ultimately classified as viable. For this, we have prepared a unique stimulation pen for which we provide the fabrication guide for do-it-yourself rapid prototyping to eliminate the need for expensive specialized commercial equipment.

Associations between upper quarter Y-balance test performance and sport-related injuries in adolescent handball players.

Handball players are at a high risk of suffering a sport-related injury. Recent studies in various adult populations (e.g., US Army soldiers/warrior athletes, and military members) showed that poor scores in the upper quarter Y-balance test (YBT-UQ) are related to an increased risk of injury. Yet, it is unclear whether this also applies to adolescent handball players. Thus, the present study aims to determine if pre-season YBT-UQ performance is associated with sport-related injuries during the competitive season in adolescent handball players. One hundred and thirty-three adolescent handball players (age: 15.4 ± 1.7 years; m = 99, f = 42) who competed in the second highest league in the Rhine-Ruhr region, Germany, during the 2021/2022 season participated in the study. Before the competitive season, the players performed the YBT-UQ to assess upper extremity mobility and stability of the throwing and non-throwing arm. Over the 8-month competitive season, the coaches monitored the occurrence of sports-related injuries once a week, using an injury report form from the legal accident insurance. Fifty-seven players (43%) incurred a sport-related injury during the competitive season, of which 27 (47%) had upper body injuries, and 30 (53%) were lower body injuries. The YBT-UQ performance of the throwing and non-throwing arm did not significantly differ between injured and non-injured players. Further, Cox proportional hazard survival regression model analyses revealed that only the presence of an inferolateral reach asymmetry score ≥7.75% arm length was associated with a moderate increase in the risk (hazard ratio = 2.18, 95% confidence interval = 1.02-4.68, p = 0.045) of lower but not upper or whole-body injuries. Our findings suggest that the YBT-UQ has limited value as a field-based screening tool to assess the risk of sport-related injuries in adolescent handball players.

Vascularization of Poly-ε-Caprolactone-Collagen I-Nanofibers with or without Sacrificial Fibers in the Neurotized Arteriovenous Loop Model.

Electrospun nanofibers represent an ideal matrix for the purpose of skeletal muscle tissue engineering due to their highly aligned structure in the nanoscale, mimicking the extracellular matrix of skeletal muscle. However, they often consist of high-density packed fibers, which might impair vascularization. The integration of polyethylene oxide (PEO) sacrificial fibers, which dissolve in water, enables the creation of less dense structures. This study examines potential benefits of poly-ε-caprolactone-collagen I-PEO-nanoscaffolds (PCP) in terms of neovascularization and distribution of newly formed vessels compared to poly-ε-caprolactone -collagen I-nanoscaffolds (PC) in a modified arteriovenous loop model in the rat. For this purpose, the superficial inferior epigastric artery and vein as well as a motor nerve branch were integrated into a multilayer three-dimensional nanofiber scaffold construct, which was enclosed by an isolation chamber. Numbers and spatial distribution of sprouting vessels as well as macrophages were analyzed via immunohistochemistry after two and four weeks of implantation. After four weeks, aligned PC showed a higher number of newly formed vessels, regardless of the compartments formed in PCP by the removal of sacrificial fibers. Both groups showed cell influx and no difference in macrophage invasion. In this study, a model of combined axial vascularization and neurotization of a PCL-collagen I-nanofiber construct could be established for the first time. These results provide a foundation for the in vivo implantation of cells, taking a major step towards the generation of functional skeletal muscle tissue.

Effects of a 6 week core strengthening training on measures of physical and athletic performance in adolescent male sub-elite handball players.

The objective was to investigate the effects of a 6-week core strengthening training within the regular handball training sessions compared to regular handball training only. Male sub-elite handball players were randomly assigned to an intervention (INT: n = 13; age: 16.9 ± 0.6 years) or a control (CON: n = 13; age: 17.2 ± 0.8 years) group. The INT group performed the "big 3" core exercises cross curls-up, side bridge (both sides), and the quadrupedal stance ("birddog exercise") triweekly for 20-30 min while the CON group conducted regular handball training only. Pre- and post-training assessments included measures of muscular endurance (Closed Kinetic Chain Upper Extremity Stability Test [CKCUEST] and the Bourban test), shoulder mobility/stability (Upper Quarter Y Balance [YBT-UQ] test), and throwing velocity. The ANCOVA revealed significant differences between means in favour of the INT group for the dorsal chain (p < 0.001, η p 2 = 0.46) and the lateral chain (left side: p = 0.015, η p 2 = 0.22; right side: p = 0.039, η p 2 = 0.17) of the Bourban test, the composite score (p = 0.024, η p 2 = 0.20) of the throwing arm reach and the inferolateral reach direction (p = 0.038, η p 2 = 0.17), and the composite score (p = 0.027, η p 2 = 0.19) of the non-throwing arm reach of the YBT-UQ. However, performance in the CKCUEST and throwing velocity did not show any group-specific changes. Therefore, 6 weeks of core strengthening training were effective in improving some components of physical but no handball-specific athletic (i.e., throwing velocity) performance in adolescent male sub-elite handball players. Practitioners may still opt for this training regimen when stimulus variability is sought or when a low load/low movement approach (e.g., during rehabilitation) is favoured.

Correlations between core muscle strength endurance and upper-extremity performance in adolescent male sub-elite handball players.

Handball is an Olympic contact sport with high physical, tactical, and technical demands by the players. Out of the different techniques, throwing is the most important one to be able to score. The objective of the study was to investigate the relationships between core muscle strength endurance (Bourban test: ventral, dorsal and lateral chain) and shoulder mobility/stability (Upper Quarter Y Balance test [YBT-UQ]) as well as throwing velocity in adolescent male sub-elite handball players (N = 32, age: 17.1 ± 0.7 years, height: 181.8 ± 6.3 cm, BMI: 24.6 ± 4.9 kg/m2). All participants were free of injuries at least two weeks prior to the study, experienced (training experience: 8.5 ± 3.3 years) handball players who were tested mid-season in the evening of one of their training sessions. Pearson correlations were calculated for core muscle strength endurance with (a) shoulder mobility/stability and (b) throwing velocity. The throwing arm reach displayed significant correlations (both p < 0.05) between the Bourban test (ventral chain) and the inferolateral reach direction (IL) of the YBT-UQ (r = 0.41) as well as the composite score (CS) (r = 0.34). For the dorsal chain, significant correlations (all p < 0.01) were found for the medial (MD) (r = 0.42) and IL (r = 0.61) reach direction as well as the CS (r = 0.51). For the right but not the left side of the lateral chain, significant correlations (both p < 0.05) were detected for the IL reach direction (r = 0.40) and the CS (r = 0.35). For the non-throwing arm reach, significant correlations were found between the ventral chain and the MD reach direction (r = 0.53, p < 0.01) as well as the CS (r = 0.31, p < 0.05). For the dorsal chain, significant correlations (all p < 0.01) were found for the MD (r = 0.47) and IL (r = 0.44) reach direction as well as the CS (r = 0.41). For the lateral chain, significant correlations were detected for the MD (left and right side: r = 0.49, p < 0.01) and IL (left and right side: r = 0.35, p < 0.05) reach direction as well as the CS (left and right side: r = 0.37, p < 0.05). The dorsal chain but not the ventral and lateral chain of the Bourban test showed a significant correlation with throwing velocity (r = 0.33, p < 0.05). Our results indicate that better core muscle strength endurance is associated with better shoulder mobility/stability as well as partially higher throwing velocity of adolescent male sub-elite handball players. Therefore, practitioners should integrate core muscle strength endurance exercises into the training routines to improve upper-extremity performance of this target group.

[Depth and integration of science modules in medical studies at recognized public and private faculties in Germany: A cross-sectional study]. / Ausmaß und Integration von Wissenschaftsmodulen in das Medizinstudium an den staatlichen Fakultäten und den privaten staatlich anerkannten Fakultäten in Deutschland: eine Querschnittsstudie.

BACKGROUND: At the end of November 2020, four years after the adoption of the Masterplan Medizinstudium 2020, the Federal Ministry of Health presented the draft bill for the revision of the medical licensing regulations. This was adapted in August 2021 and stipulates, among other things, the completion of a mandatory scientific project up to the second stage of the medical examination, which is to be conducted within twelve weeks and based on the structured teaching of scientific skills using longitudinal courses. This study examines to what extent the mentioned aspects of the draft bill are already included in the current compulsory curricula in German medical study programs. METHODS: In a cross-sectional study, we conducted a document analysis and an online survey of the student deaneries of state and private, state-recognized faculties of medicine in Germany. The objective was to assess the integration of curricular science projects and longitudinal science modules. The data was analyzed descriptively. RESULTS: In total, 40 (93%) of 43 faculties were included in the document analysis. 26 (60.5%) of 43 academic deans responded to the online questionnaire. Only twelve (30%) of the faculties offer a mandatory science project according to the document analysis and eight (30.8%) according to the evaluation of the online survey. In relative terms, a mandatory science project is already a curricular component in the majority of model and reform degree programs (document analysis: 83.3%, n=10 / N=12; questionnaire: 87.5%, n=7 / N=8). This contrasts with a significantly smaller number of regular degree programs that currently offer a science project as a mandatory component (document analysis: 16.7%, n=2 / N=12; questionnaire: 12.5%, n=1 / N=8). In the majority of the model and reform courses, a compulsory (longitudinal) science module has already been integrated into the curriculum (document analysis: 75%, n=12 / N=16; questionnaire: 55.5%, n=6 / N=11). This is only true for 25% (n=4 / N=12; document analysis) and 44.5% (n=5 / N=11; questionnaire) of the regular courses. DISCUSSION: The results of the surveys indicate that the regular study programs, in particular, need to be restructured in order to integrate the intended time frame of twelve weeks for an obligatory science project into the current curriculum. How this is to be achieved without reducing the existing study content seems to be still unclear. Regardless of the current draft bill, however, this step appears to be necessary in order to strengthen the acquisition of scientific competencies in medical studies and to adapt it to international medical education. CONCLUSION: The majority of the current model and reformed medical study courses already fulfill the requirements of the draft bill for the new licensing regulations with regard to the curricular integration of an obligatory scientific project and longitudinal strand on scientific work, which offer hints on design possibilities for further faculties.

Myofibrillar Lattice Remodeling Is a Structural Cytoskeletal Predictor of Diaphragm Muscle Weakness in a Fibrotic mdx (mdx Cmah-/-) Model.

Duchenne muscular dystrophy (DMD) is a degenerative genetic myopathy characterized by complete absence of dystrophin. Although the mdx mouse lacks dystrophin, its phenotype is milder compared to DMD patients. The incorporation of a null mutation in the Cmah gene led to a more DMD-like phenotype (i.e., more fibrosis). Although fibrosis is thought to be the major determinant of 'structural weakness', intracellular remodeling of myofibrillar geometry was shown to be a major cellular determinant thereof. To dissect the respective contribution to muscle weakness, we assessed biomechanics and extra- and intracellular architecture of whole muscle and single fibers from extensor digitorum longus (EDL) and diaphragm. Despite increased collagen contents in both muscles, passive stiffness in mdx Cmah-/- diaphragm was similar to wt mice (EDL muscles were twice as stiff). Isometric twitch and tetanic stresses were 50% reduced in mdx Cmah-/- diaphragm (15% in EDL). Myofibrillar architecture was severely compromised in mdx Cmah-/- single fibers of both muscle types, but more pronounced in diaphragm. Our results show that the mdx Cmah-/- genotype reproduces DMD-like fibrosis but is not associated with changes in passive visco-elastic muscle stiffness. Furthermore, detriments in active isometric force are compatible with the pronounced myofibrillar disarray of the dystrophic background.

Salt-induced conformational switching of a flat rectangular DNA origami structure.

A rectangular DNA origami structure is one of the most studied and often used motif for applications in DNA nanotechnology. Here, we present two assays to study structural changes in DNA nanostructures and reveal a reversible rolling-up of the rectangular DNA origami structure induced by bivalent cations such as magnesium or calcium. First, we applied one-color and two-color superresolution DNA-PAINT with protruding strands along the long edges of the DNA origami rectangle. At increasing salt concentration, a single line instead of two lines is observed as a first indicator of rolling-up. Two-color measurements also revealed different conformations with parallel and angled edges. Second, we placed a gold nanoparticle and a dye molecule at different positions on the DNA origami structure. Distance dependent fluorescence quenching by the nanoparticle reports on dynamic transitions as well as it provides evidence that the rolling-up occurs preferentially along the diagonal of the DNA origami rectangle. The results will be helpful to test DNA structural models and the assays presented will be useful to study further structural transitions in DNA nanotechnology.

Diverging Playing Positions do not Lead to Differences in YBT-UQ Performance in Youth Handball Players.

Handball playing positions can be differentiated between first line players who position themselves near the 6-m line and second line players who typically play outside the 9-m space. Handball is characterized by a high number of throwing actions that cause adaptations in the throwing shoulder. The objective of this cross-sectional study was to assess whether the specific physiological positional demands in handball lead to functional performance differences between the playing positions ( N =196; goalkeepers: n =25; backcourt: n =99; pivots: n =21; winger: n =51) in terms of shoulder mobility and stability in any reach direction as assessed through the Upper Quarter Y Balance Test (YBT-UQ). Contrary to our hypothesis, the results did not show significant differences between the playing positions in shoulder mobility and stability in youth handball players, irrespective of reach arm and reach direction. The obtained effect sizes ( η p 2 ) were solely small and ranged between 0.01 and 0.03. The adaptations following the demands of the diverging playing positions do not lead to significant differences in shoulder mobility and stability on the basis of the YBT-UQ. The overall training load of youth handball players may not be sufficient to lead to significant position-specific differences in shoulder mobility and stability.

Side differences of upper quarter Y balance test performance in sub-elite young male and female handball players with different ages.

BACKGROUND: Handball is characterised by repetitive passing and shooting actions mainly performed with the throwing arm. This can lead to side differences (inter-limb asymmetry) in upper quarter mobility/stability between the throwing and non-throwing arm, which could even increase with advancing age (i.e., playing experience). However, side differences in upper quarter mobility/stability is associated with an increased musculoskeletal injury risk. Therefore, we assessed side differences in upper quarter mobility/stability in young handball players at different ages using a cross-sectional study design. METHODS: Upper Quarter Y Balance test performance of the throwing and non-throwing arm was assessed in 190 sub-elite young female and male handball players (13-18 years). Per arm, relative maximal reach distances (% arm length) for all three directions (i.e., medial, inferolateral, superolateral) and the composite score (CS) were calculated and used for an age × side analysis of variance. Additionally, partial eta-squared (ηp2) was calculated as an effect size measure. RESULTS: Irrespective of measure, statistically significant main effects of age (except for the composite score) and side but no statistically significant age × side interaction effects were detected. Further, limb asymmetry in the inferolateral reach direction was above the injury-related cut-off value (i.e., ≥ 7.75% arm length) in 13- and 14-year-olds but not in the older players. CONCLUSION: The detection of limb asymmetry above the proposed injury-related cut-off value in younger players (13- and 14-year-olds) but not in older players (15- to 18-year-olds) may be indicative for an increased injury risk for the younger age group. Thus, prevention programs should be implemented in the handball training routine, especially for the younger ones.

Comparison of Lower and Upper Quarter Y Balance Test Performance in Adolescent Students with Borderline Intellectual Functioning Compared to Age- and Sex-Matched Controls.

The Lower (YBT-LQ) and Upper (YBT-UQ) Quarter Y Balance Test are well established assessment tools for the examination of dynamic balance and shoulder mobility/stability, respectively. However, investigations on YBT-LQ/UQ performance in students with borderline intellectual functioning (BIF) (i.e., intelligence quotient of 70-84 etc.) are lacking. Thus, the aim of the study was to compare YBT-LQ/UQ performance in students with and without BIF. Thirty students with BIF (age: 13.7 ± 1.2 years) and 30 age-/sex-matched students without BIF (age: 13.7 ± 1.3 years) performed the YBT-LQ and/or YBT-UQ. Normalized maximal reach distances (% leg/arm length) per reach direction and the composite score were used as outcome measures. A univariate analysis of variance was conducted to test for significant group differences. Irrespective of limb and reach direction, students with BIF compared to those without BIF showed significantly worse YBT-LQ (p ≤ 0.001-0.031; Cohen's d = 0.57-1.26) and YBT-UQ (p ≤ 0.001-0.015; Cohen's d = 0.68-1.52) performance with moderate to large effect sizes. Due to the poorer performance levels of students with BIF, specifically tailored interventions should be developed that have the potential to improve their dynamic balance and shoulder mobility/stability.

Effects of an Elastic Resistance Band Intervention in Adolescent Handball Players.

The objective was to investigate the effects of a 9-week elastic resistance band training within the regular handball training sessions compared to regular handball training only. Participants were randomly assigned to an intervention (INT: n=16; age: 17.0 ± 0.7 years) or a control (CON: n=16; age: 16.9 ± 0.9 years) group. The INT-group performed elastic resistance band exercises (3/week) for 20-30 minutes while the CON-group conducted regular handball training only. Pre- and post-training assessments included measures of strength endurance (Closed Kinetic Chain Upper Extremity Stability Test [CKCUEST]), maximal isometric strength (MIS), and throwing velocity. Significant main effects of Test (i.e. pre- to post-training enhancements) were detected for the CKCUEST (p < 0.001, 0.54 ≤ η p 2 ≤ 0.57) and throwing velocity (p = 0.001, η p 2 = 0.34). We found a significant (throwing velocity: p = 0.004, η p 2 = 0.25) and a tendency toward (MIS of the internal rotators, non-throwing arm: p = 0.068, η p 2 = 0.12) a significant Test × Group interaction, both in favour of the INT-group. A 9-week strengthening program using elastic resistance bands combined with regular handball training is effective to improve upper extremity strength endurance, throwing velocity, and MIS of the internal rotators of the non-throwing arm.

Tracking single particles for hours via continuous DNA-mediated fluorophore exchange.

Monitoring biomolecules in single-particle tracking experiments is typically achieved by employing fixed organic dyes or fluorescent fusion proteins linked to a target of interest. However, photobleaching typically limits observation times to merely a few seconds, restricting downstream statistical analysis and observation of rare biological events. Here, we overcome this inherent limitation via continuous fluorophore exchange using DNA-PAINT, where fluorescently-labeled oligonucleotides reversibly bind to a single-stranded DNA handle attached to the target molecule. Such versatile and facile labeling allows uninterrupted monitoring of single molecules for extended durations. We demonstrate the power of our approach by observing DNA origami on membranes for tens of minutes, providing perspectives for investigating cellular processes on physiologically relevant timescales.

Upper Quarter Y Balance test performance: Normative values for healthy youth aged 10 to 17 years.

BACKGROUND: The Upper Quarter Y Balance test (YBT-UQ) is a field test for measuring shoulder mobility/stability. However, there is a lack of information regarding age- and sex-specific reference values for classifying the YBT-UQ performance of children and adolescents. OBJECTIVE: The aim was to investigate YBT-UQ performance in youth and to provide age- and sex-specific normative values. METHOD: Six hundred and sixty-five persons (325 girls, 340 boys) aged between 10 and 17 years carried out the YBT-UQ test. Following this, maximum reach values, normalised in terms of arm length, were calculated for each arm (i.e., left and right) and reach direction (i.e., medial [MD], inferolateral [IL], superolateral [SL]), and the composite score (CS) per arm. Additionally, percentiles were displayed graphically and in tabular form, distinguished according to age and gender. RESULTS: In boys, those aged 14-15 years showed a higher achievement (e.g., MD direction) compared with both younger (12-13-year-olds) and older (16-17-year-olds) persons. In girls, differences related to age could only be observed for the IL direction and the CS, where the youngest age group (10-11-year-olds) achieved better results than the older groups. Sex-specific differences to the girls' advantage could be observed in 12-13-year-olds (i.e., SL and CS), and to the boys' advantage in 14-15-year-olds (i.e., for all reach directions) and 16-17-year-olds (i.e., IL and SL direction and CS). Further, curvilinear developments were observed with regard to the 10th, 50th, and 90th percentiles, and were more strongly marked in boys than in girls. CONCLUSIONS: The obtained age- and sex-specific normative values for the YBT-UQ can be used by teachers, coaches, and therapists to classify the level of shoulder mobility/stability among 10-17 year-old children and adolescents.

[Integrating academic nurses in German university hospitals: a follow-up survey]. / Einbindung von Pflegefachpersonen mit Hochschulabschlüssen an deutschen Universitätskliniken: ein Follow-up-Survey.

INTRODUCTION: The effective integration of professional nursing staff with university training into care processes is associated internationally with better patient outcomes. In Germany, there is a current lack of reliable figures on graduates and their areas of responsibility. Therefore, the aim of this follow-up survey, designed as a repetition of a previous one, was to ascertain the number of nurses with a Bachelor's or Master's degree involved in direct patient care at university medical centers. METHOD: In a cross-sectional study, chief nursing officers in university medical centers were asked to quote the number of professional nurses with a university degree (Bachelor, Master, Doctorate). Additional questions focused on their tasks and responsibilities and the measures undertaken to facilitate their integration into the organization. The data were analyzed using descriptive statistics. RESULTS: In total, n=29 valid questionnaires from 35 university medical centers were included in the analysis, resulting in a response rate of 82.85%. For a total of 18 centers, the number of university-qualified nurses had increased by n=786 between 2015 (n=593) and 2018 (n=1,379). The overall percentage of nurses with a university degree working at a university medical center in the study was 3.16% (SD=1.66; min - max=1.09 - 6.69; Q1 - Q3=1.49 - 4.04; 95% CI 2.30 to 3.95). In direct patient care, the quota was 2.11% (SD=1.40; min - max=0.47 - 5.42; Q1 - Q3=0.87 - 3.16; 95% CI 1.36 to 2.76). The main focus of their duties was on standard care and patient education (graduates with a Bachelor's degree), evidence-based nursing practice development (Master's degree) and research activities (doctoral degree). DISCUSSION: Compared to 2015, the proportion of professional nursing staff with university training has increased but remains at a very low level. These nurses perform relevant clinical tasks and are involved in the development of good practice. However, there is a need for better competence-based differentiation.