bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic hybrid materials interact with biological matrices
Authors: Gräfe Christine , Müller Elena K. , Gresing Lennart , Weidner Andreas , Radon Patricia , Friedrich Ralf P. , Alexiou Christoph , Wiekhorst Frank , Dutz Silvio , Clement Joachim H. 
Published: January 2021

Abstract
Magnetic hybrid materials are a promising group of substances. Their interaction with matrices is challenging with regard to the underlying physical and chemical mechanisms. But thinking matrices as biological membranes or even structured cell layers they become interesting with regard to potential biomedical applications. Therefore, we established in vitro blood-organ barrier models to study the interaction and processing of superparamagnetic iron oxide nanoparticles (SPIONs) with these cellular structures in the presence of a magnetic field gradient. A one-cell-type–based blood-brain barrier model was used to investigate the attachment and uptake mechanisms of differentially charged magnetic hybrid materials. Inhibition of clathrin-dependent endocytosis and F-actin depolymerization led to a dramatic reduction of cellular uptake. Furthermore, the subsequent transportation of SPIONs through the barrier and the ability to detect these particles was of interest. Negatively charged SPIONs could be detected behind the barrier as well as in a reporter cell line. These observations could be confirmed with a two-cell-type–based blood-placenta barrier model. While positively charged SPIONs heavily interact with the apical cell layer, neutrally charged SPIONs showed a retarded interaction behavior. Behind the blood-placenta barrier, negatively charged SPIONs could be clearly detected. Finally, the transfer of the in vitro blood-placenta model in a microfluidic biochip allows the integration of shear stress into the system. Even without particle accumulation in a magnetic field gradient, the negatively charged SPIONs were detectable behind the barrier. In conclusion, in vitro blood-organ barrier models allow the broad investigation of magnetic hybrid materials with regard to biocompatibility, cell interaction, and transfer through cell layers on their way to biomedical application.
Magnetoactive elastomers for magnetically tunable vibrating sensor systems
Authors: Becker Tatiana I. , Raikher Yuriy L. , Stolbov Oleg V. , Böhm Valter , Zimmermann Klaus 
Published: January 2021

Abstract
Magnetoactive elastomers (MAEs) are a special type of smart materials consisting of an elastic matrix with embedded microsized particles that are made of ferromagnetic materials with high or low coercivity. Due to their composition, such elastomers possess unique magnetic field-dependent material properties. The present paper compiles the results of investigations on MAEs towards an approach of their potential application as vibrating sensor elements with adaptable sensitivity. Starting with the model-based and experimental studies of the free vibrational behavior displayed by cantilevers made of MAEs, it is shown that the first bending eigenfrequency of the cantilevers depends strongly on the strength of an applied uniform magnetic field. The investigations of the forced vibration response of MAE beams subjected to in-plane kinematic excitation confirm the possibility of active magnetic control of the amplitude-frequency characteristics. With change of the uniform field strength, the MAE beam reveals different steady-state responses for the same excitation, and the resonance may occur at various ranges of the excitation frequency. Nonlinear dependencies of the amplification ratio on the excitation frequency are obtained for different magnitudes of the applied field. Furthermore, it is shown that the steady-state vibrations of MAE beams can be detected based on the magnetic field distortion. The field difference, which is measured simultaneously on the sides of a vibrating MAE beam, provides a signal with the same frequency as the excitation and an amplitude proportional to the amplitude of resulting vibrations. The presented prototype of the MAE-based vibrating unit with the field-controlled “configuration” can be implemented for realization of acceleration sensor systems with adaptable sensitivity. The ongoing research on MAEs is oriented to the use of other geometrical forms along with beams, e.g. two-dimensional structures such as membranes.
Cushioning energy absorption of regular polygonal paper corrugation tubes under axial drop impact
Authors: Guo Yanfeng , Ji Meijuan , Fu Yungang , Xia Ronghou , Pan Dan , Tang Weigao 
Published: January 2021

Abstract
The paper corrugation tube is an attractive and innovative mode of cushioning protection and energy absorption for the general protection and packaging technology of military and civil products. The aims of this paper focus on the dynamic compression characteristics of four kinds of regular polygonal paper corrugation tubes under the conditions of axial drop impacts, and the influence rules of structural parameters and load parameters on the dynamic cushioning energy absorption. The results show that, the tube direction has a crucial effect on the deformation mode of the paper corrugation tubes, the deformation of X-direction paper corrugation tubes has a stable accordion mode, but that of Y-direction paper corrugation tubes is a mixture of steady progressive buckling and other non-ideal modes. The X-direction paper corrugation tubes have lower peak stress, stable and controllable deformation mode with multiple folds, and higher total energy absorption, unit area energy absorption, specific energy absorption and stroke efficiency than the Y-direction paper corrugation tubes. Moreover, the change of cross-section shape of X-direction paper corrugation tubes has no obvious influence on the total energy absorption, while the total energy absorption of Y-direction paper corrugation tube obviously rises with the increase of the number of cross-section edges of the tubes, but the unit area energy absorption, specific energy absorption and stroke efficiency decrease with the increase of the number of cross-section edges of the tubes. Moreover, the increase of the number of cross-section edges of the tubes made the total energy absorption of Y-direction tubes rise, while the total energy absorption of X-direction tubes has no obvious change. But the unit area energy absorption, specific energy absorption and stroke efficiency decrease with the increase of the number of cross-section edges of the tubes. Furthermore, the tube length, impact block mass and impact energy have also important influence on the cushioning energy absorption of the paper corrugation tubes under axial drop impact.
Eriodictyol corrects functional recovery and myelin loss in SCI rats
Authors: Li Chenggang , Wang Chunfang 
Published: January 2021

Abstract

Background
This study investigated the therapeutic potential of eriodictyol (EDC) in spinal cord injury (SCI) rats and also the mechanism involved.

Methods
The SCI model was created in Sprague-Dawley rats by the weight drop method. The SCI rats were divided into four groups, namely, Sham operated group (submitted for laminectomy only), control rats (vehicle treated), rats treated with 10 mg/kg EDC and rats treated with 20 mg/kg EDC. EDC or vehicle was injected in The SCI rats via subarachnoid route at the lumbar level 4 just after inducing SCI. The open field and inclined plane tests were done for assessing the locomotor activity. Histopathological analysis of the injured site of the spinal cord was done. Western blot analysis and immunohistochemical analysis were done for the expression of Bcl-2, Bax, glial cell line–derived neurotrophic factor (GCDNF) and brain-derived neurotrophic factor (BDNF).

Results
The outcomes suggested that EDC-treated rats showed significant improvement in the locomotor activity and also exhibited low myelin loss. The rats also showed overexpression of Bcl-2 and Bax. The treatment of EDC also increased the levels of GCDNF and BDNF after SCI. These outcomes suggested that EDC exerted the neuroprotective effect and also improved the locomotor activity by improving the levels of GCDNF and BDNF and blocking the apoptosis-related proteins.

Conclusion
This study suggests that EDC could ameliorate the locomotor function, and the neuroprotective action may be attributed to modulation of GCDNF and BDNF and blockade of apoptosis-associated proteins.
Bone Mineral Density Differences Across Female Olympic Lifters, Power Lifters, and Soccer Players
Authors: Jeon Woohyoung , Harrison John Michael , Stanforth Philip R. , Griffin Lisa 
Published: January 2021

Abstract
Jeon, W, Harrison, JM, Stanforth, PR, and Griffin, L. Bone mineral density differences across female Olympic lifters, power lifters, and soccer players. J Strength Cond Res 35(3): 638–643, 2021—Athletic training improves bone mineral density (BMD) through repeated mechanical loading. The location, intensity, and direction of applied mechanical pressure play an important role in determining BMD, making some sports more advantageous at improving BMD at specific regions. Thirty-seven (10 power lifters [PL], 8 Olympic lifters [OL], 8 soccer players [SP], and 11 recreationally active [RA]) women participated in a cross-sectional study. We measured lumbar spine (L1-L4), femoral neck, total-body BMD, and overall body composition (total fat mass, lean mass, percent body fat) with dual-energy x-ray absorptiometry. All athletic groups had greater total BMD than RA (p = 0.01 [PL]; p < 0.001 [OL]; p = 0.01 [SP]). Olympic lifters had the highest total BMD than all other athletic groups. Olympic lifters had the significantly greater total BMD than PL (p = 0.018), but there was no difference in total BMD between PL and SP. As compared with RA, OL showed greater BMD at both the total lumbar spine (p = 0.002) and the femoral neck (p = 0.007), whereas PL showed greater BMD only for the total lumbar spine (p = 0.019) and SP showed greater BMD only for the femoral neck (p = 0.002). Olympic-style lifting includes both high-impact and odd-impact loading modalities that are associated with the highest BMD at both the lumbar spine and femoral neck.
Biomechanical Analysis of the Tuck Jump Assessment
Authors: Nascimento Nuno , Sideris Vasileios , Read Paul J. 
Published: January 2021

Abstract
Nascimento, N, Sideris, V, and Read, PJ. Biomechanical analysis of the tuck jump assessment. J Strength Cond Res 36(10): 2946–2949, 2022—The tuck jump assessment (TJA) examines plyometric technique flaws associated with the increased risk of anterior cruciate ligament injury. Biomechanical data to investigate the mechanics used during the TJA are limited and assessing each jump individually across the entire test period is time inefficient. This study examined performance characteristics and movement mechanics in 16 professional soccer players during a standardized TJA protocol (10 jumps) to determine if sensitive periods exist within the test period (first 5 vs. last 5). Jump height, average power (PW) reactive strength index (RSI), frontal plane projection angle (FPPA), knee angular velocity (AV), and peak knee flexion angle (PKA) were analyzed using an optoelectrical and inertial measurement unit device. Jump height and PW increased in the past 5 jumps displaying a medium effect size (d = > 0.5). A trend was observed of increased AV, FPPA, and PKA during the past 5 jumps; however, no meaningful differences were observed between respective jump phases, and effect sizes were small (d ≤ 0.2). This study indicates that performance metrics increase during the past 5 jumps of a standardized TJA 10-jump protocol; thus, analyzing the entire test period may not be required, providing a time-efficient approach. Caution should be applied if using this protocol as an injury risk screening tool or to identify fatigue related alterations in male professional soccer players as no obvious movement abnormalities were apparent and minimal differences were present between jump phases in a range of kinematic variables across the recorded test duration.
Does Varying Repetition Tempo in a Single-Joint Lower Body Exercise Augment Muscle Size and Strength in Resistance-Trained Men?
Authors: Pearson Jeremy , Wadhi Tanuj , Barakat Christopher , Aube Daniel , Schoenfeld Brad J. , Andersen Jody C. , Barroso Renato , Ugrinowitsch Carlos , De Souza Eduardo O. 
Published: January 2021

Abstract
Pearson, J, Wadhi, T, Barakat, C, Aube, D, Schoenfeld, BJ, Andersen, JC, Barroso, R, Ugrinowitsch, C, and De Souza, EO. Does varying repetition tempo in a single-joint lower body exercise augment muscle size and strength in resistance-trained men? J Strength Cond Res 36(8): 2162–2168, 2022—This study compared the effects of FAST and SLOW eccentric repetition tempo in a single exercise volume-matched intervention on muscle thickness (MT) and strength in resistance-trained men. Using a within-subject design, 13 subjects had each leg randomly assigned to SLOW (1-0-3) or FAST (1-0-1) repetition tempo. Subjects underwent an 8-week strength-training (ST) intervention performed twice weekly. Unilateral leg-extension one repetition-maximum (1RM) and anterior thigh MT at the proximal (MTP) and distal (MTD) portions were assessed via ultrasound imaging at baseline and after 8 weeks of RT. Rating of perceived exertion (RPE) assessments of the training sessions (i.e., 16 per leg) were averaged for further analysis. Both legs similarly increased MTP (estimated differences: FAST: 0.24 cm, 3.6%; SLOW: 0.20 cm, 3.1%). However, for MTD, analysis of covariance analysis showed a leg effect (p = 0.02) in which absolute pre-to-post change was greater in FAST compared with SLOW (estimated differences: FAST 0.23 cm, 5.5%; SLOW: 0.13 cm, 2.2%). For 1RM, both legs similarly increased maximum strength (estimated differences: FAST: 9.1 kg, 17.0%; SLOW: 10.4 kg, 22.1%, p ≤ 0.0001). The SLOW group had a higher RPE than FAST (8.59 vs. 7.98, p = 0.002). Despite differences in RPE, our results indicate that both repetition tempos produced similar muscular adaptations. However, they also suggest that the FAST tempo may provide a small hypertrophic advantage at the distal quadriceps. From a practical standpoint, strength and conditioning professionals may implement a FAST tempo at least in one single-joint exercise during an 8-week training period to enhance regional hypertrophic adaptations in trained individuals.
Personal, Work-, and Client-Related Burnout Within Strength and Conditioning Coaches and Personal Trainers
Authors: Snarr Ronald L. , Beasley Vista L. 
Published: January 2021

Abstract
Snarr, RL and Beasley, VL. Personal, work-, and client-related burnout within strength and conditioning coaches and personal trainers. J Strength Cond Res 36(2): e31–e40, 2022—The purpose of this investigation was to examine the prevalence and influencing factors of personal, work-related, and client-related burnout within strength and conditioning coaches (SCCs) and personal trainers (PTs). Two hundred fifty-six SCCs (n = 141) and PTs (n = 115) completed the Copenhagen Burnout Inventory (CBI), a 19-item survey, measuring 3 subscales of personal, work-related, and client-related burnout. Information regarding other burnout-related factors (i.e., job satisfaction, social support, fitness level, and mental toughness) was solicited through single-item or multiple-item questionnaires. Correlational analyses and independent t-tests were conducted to assess associations and between-group differences between burnout and all continuous factors. Seventy-one subjects completed the survey before March 2020; after which, a worldwide pandemic (i.e., COVID-19) occurred possibly affecting employment workloads and work-related stress. Thus, post hoc analyses were conducted to assess differences in burnout scores pre-COVID-19 and post-COVID-19. Using a CBI subscale cutoff score of ≥50, fitness professionals reported 32.8% of personal burnout, 28.5% work-related burnout, and 18.0% client-related burnout. Factored by occupation, SCCs reported 32.6% personal burnout, 27.7% work-related burnout, and 18.4% client-related burnout. Within PTs, 33.0% reported personal burnout, 29.6% reported work-related burnout, and 17.4% reported client-related burnout. Higher levels of burnout, across all scales, were observed in those who were PTs, women, unmarried, living alone, would not choose to be a fitness professional again, and took the survey post-COVID as compared to their respective counterparts. Findings suggest that fitness professionals are not exempt from the stressors associated with personal and occupational burnout. Strength and conditioning coaches and PTs may reduce the risk of burnout by increasing social support, continuing education, and allowing for personal-care time with the intention of buffering these factors.
Velocity Change Estimation by Subjective Measures Over a Wide-Load Spectrum in Squat and Bench Press
Authors: Chapman Mark , Larumbe-Zabala Eneko , Triplett N. Travis , Naclerio Fernando 
Published: January 2021

Abstract
Chapman, M, Larumbe-Zabala, E, Triplett, NT, and Naclerio, F. Velocity change estimation by subjective measures over a wide-load spectrum in squat and bench press. J Strength Cond Res 35(2S): S51–S56, 2021—This study compared whether the perception of effort measured on a repetition-by-repetition basis during continuous sets to failure is different between squat (SQ) and bench press (BP). After determining the one repetition maximum (1RM) value in both SQ and BP, 18 subjects (28.2 ± 5 years, 50% women) performed 7 sets to failure per exercise, separated by 24–48 hours, alternating SQ and BP, using the following relative load ranges: 30 < 40%, 40 < 50%, 50 < 60%, 60% < 70%, 70 < 80%, 80 < 90%, and >90%. The mean accelerative velocity (MAV) and rating of perceived exertion (RPE) using the OMNI-RES (0–10) scale were measured for every repetition of each set. The ability of the OMNI-RES (0–10) scale to identify velocity changes during continuous sets to volitional failure and to distinguish loading zones divided into 10% slots, from 30 to 100% of 1RM was confirmed for both SQ and BP. The RPE values measured at (a) the first repetition; (b) the repetition where MAV peaks; (c) the repetition where MAV drops by ≤10% compared the maximum and (d) the last repetition, showed no differences (p > 0.05, d < 0.2) between exercises. In conclusion, the same RPE scores can be applied to both exercises, for either estimating the relative load or monitoring changes in MAV during continuous sets to failure.
Influence of Movement Velocity on Accuracy of Estimated Repetitions to Failure in Resistance-Trained Men
Authors: Hackett Daniel A. 
Published: January 2021

Abstract
Hackett, DA. Influence of movement velocity on accuracy of estimated repetitions to failure in resistance-trained men. J Strength Cond Res 36(10): 2701–2708, 2022—This study explored the accuracy in estimated repetitions to failure (ERF) and changes in mean concentric velocity (MCV) during resistance exercise. Twenty male resistance trainers (age, 26.3 ± 6.9 years; body mass, 82.0 ± 6.0 kg; stature, 178.0 ± 5.5 cm) completed 5 sets of 10 repetitions for the bench press and squat at 70% one-repetition maximum. Subjects' reported their rating of perceived exertion (RPE) and ERF after the 10th repetition of each set and then continued repetitions to momentary muscle failure (5-minute recovery between sets). Barbell velocity was assessed using a linear position transducer. For the bench press, MCV at repetitions 9–10 decreased as sets progressed (p ≤ 0.005) with a greater loss of MCV for sets 3–5 vs. set 1 (p ≤ 0.005). No significant changes in MCV variables were found across sets for the squat. Error in ERF was greater in set 1 for the bench press (p ≤ 0.005) with no differences for the remaining sets. There were no differences between sets for error in ERF for the squat. Moderate to strong relationships were found between most MCV variables and RPE and ERF, for the bench press (r
s = −049 to 0.73; p ≤ 0.005). For the squat only, MCV at repetitions 9–10 was moderately related with RPE (r
s = −0.33; p ≤ 0.003) and actual repetitions to failure (r
s = 0.31; p ≤ 0.003). No significant relationships were found for error in ERF for either the bench press or squat. Changes in MCV across sets may influence perception of effort and performance for the bench press; however, it does not influence the accuracy in ERF for either exercise.
The Effect of Working Capital Management on Dividend Policy: An Empirical Analysis of Listed Firms in Ghana
Authors: Yakubu Ibrahim Nandom 
Published: January 2021

Relying on more recent data spanning 2007-2016, this paper investigates the impact of working capital management (WCM) on dividend policy of listed non-financial firms in Ghana. Specifically, the study assesses the effect of cash conversion cycle (CCC), days inventory outstanding (DIO), profitability, and firm growth on dividend policy. Employing the ordinary least squares (OLS) analytical technique, the findings reported that working capital management (in terms of cash conversion cycle and days inventory outstanding) and dividend policy are positively related, with DIO having a significant effect on dividend policy. The results also established a positive association between the control variables (profitability and firm growth) and dividend policy albeit insignificantly. Based on the findings, the study concludes that working capital management in terms of days inventory outstanding (DIO) is a critical factor influencing firms’ dividend policy decisions. The study extends the inconclusive empirical evidence on the determinants of dividend policy and fills the lacuna in existing literature by focusing on how working capital management practices influence dividend policy of firms in Ghana. The findings are also useful to the board of directors of non-financial firms in deciding an appropriate dividend policy, and to the shareholders in making investment decisions.