Correlation Between Grip Strength at Various Arm Orientations and Hitting Performance Metrics of Division I Collegiate Baseball Players

Dominate and non-dominate grip strength (GS) significantly correlated with bat speed (BS) in the sport of baseball. Various arm orientations occur throughout the swing; moreover, additional metrics beyond BS are indicative of baseball hitting performance. The correlation between various GS and hitting outcomes have not been empirically examined. PURPOSE: The aim of the current investigation was to examine the relationship of GS at various arm angles to various hitting performance metrics. METHODS: Division I collegiate baseball players (n = 17; height: 180.92 ± 5.61 cm; weight: 82.1 ± 11.12 kg) performed dominate and non-dominate maximal GS at five different arm and forearm orientations utilizing the Jamar Hydraulic Hand Dynamometer: 90-degree elbow flexion with (1) neutral (NDN), (2) supinated (NDS), and (3) pronated (NDP) forearm placement, as well as 120-degree elbow extension with 90-degree shoulder abduction with (4) supinated (AS) and (5) neutral (AN) forearm grips. At each angle, three attempts were permitted to exert maximal force, recorded in kg. Hitting metrics were gathered via Blast Motion Bat Sensors and Yakkertek Ball-Tracking System - metrics included: BS, peak hand speed (PHS), vertical bat angle (VBA), time to contact (TTC), attack angle (AA), power (PW), on plane efficiency (OPE), plane score (PS), rotational acceleration (RA), early connection (EC), connection at impact (CAI), as well as average exit-velocity (AEV), peak exit-velocity (PEV), hard hit percentage (HHP), damage percentage (DP), and average launch angle (ALA). A Pearson product-moment correlation coefficient (p \u3c .05) was employed to assess the relationship between GS and hitting performance. RESULT: Positive significant correlations were recognized between the following variables: dominate NDN and HHP (r = .559, p = .02), DP (r = .647, p = .007), and BS (r = .515, p = .034); non-dominate NDP and HHP (r = .497, p = .042), DP (r = .664, p = .005), and TTC (r = .519, p = .033); and non-dominate NDS and DP (r = .770, p \u3c .001), PS (r = .515, p = .035), OPE (r = .510, p = .036). A negative significant relationship was identified between non-dominate NDS and EC (r = -.629, p = -.007), and CAI (r = -.587, p = -.013). CONCLUSION: Supporting previous investigations, these results suggest dominate NDN, non-dominate NDP, and non-dominate NDS yielded the greatest influence on hitting performance among the tested GS positions; thus, potentially providing coaches with arm orientation specific GS training recommendation for baseball hitters

Study of Shear Properties of Nanoparticle Suspensions

Low-frequency complex shear modulus of the colloidal suspensions of nanoparticles Nd:YAG in ethylene glycol was measured for the first time by using acoustic a resonance method with piezoquartz vibrator. Dependence of viscoelastic properties of the colloidal suspensions on nanoparticles sizes and their concentrations has been carried out

X-ray emission from Westerlund 2 detected by SRG/ART-XC and Chandra: search for radiation of TeV leptons

We present the results of current observations of the young compact cluster of massive stars Westerlund 2 with the Mikhail Pavlinsky ART-XC telescope aboard the Spectrum-Roentgen-Gamma (SRG) observatory which we analysed together with the archival Chandra data. In general, Westerlund 2 was detected over the whole electromagnetic spectrum including high-energy gamma rays, which revealed a cosmic ray acceleration in this object to the energies up to tens of TeV. The detection of Westerlund 2 with ART-XC allowed us to perform a joint spectral analysis together with the high resolution Chandra observations of the diffuse emission from a few selected regions in the vicinity of the Westerlund 2 core in the 0.4 - 20 keV range. To fit the Westerlund 2 X-ray spectrum above a few keV one needs either a non-thermal power-law emission component, or a hot plasma with temperatures $\sim$ 5 keV. Our magnetohydrodynamic modeling of the plasma flows in Westerlund 2 shows substantially lower electron temperatures in the system and thus the presence of the non-thermal component is certainly preferable. A kinetic model of the particle acceleration demonstrated that the non-thermal component may originate from the synchrotron radiation of multi-TeV electrons and positrons produced in Westerlund 2 in accordance with the TeV photons detection from the source. However, the inverse Compton radiation of mildly relativistic electrons could explain the non-thermal emission as well.Comment: 10 pages, 6 figures, submitted to MNRA

The Relationship between 60-yard sprint, 30-yard sprint, Standardized Base Stealing Sprint, and Offensive Baseball Performance

Athletic performance testing protocols strive to accurately predicting or gain better understanding of an athlete’s performance within a particular sport or game. Regarding baseball, Wolfe and colleagues (2012) examined the predictive validity of the 60-yard shuttle run on pitching performance and concluded that strikeouts and innings pitched were significantly related to elevated kinetic energy factors of pitchers obtained from the shuttle run performance. Concerning for baseball position players, the 60-yard sprint (60YS) is traditionally utilized to showcase “baseball speed”, with minimal empirical evident supporting predictability to baseball specific performance outcomes. PURPOSE: The aim of the current investigation was to have examine the relationship between 60YS and offensive baseball performance outcomes, as well as the 30-yard sprint (30YS) test, and newly created standardized 1st to 2nd sprint (STS) test relationship to offensive baseball performance outcomes. METHODS: Division I baseball position players (n = 17; height: 180.92 ± 5.61 cm; weight: 82.1 ± 11.12 kg) performed three sprinting tests: 60YS, 30YS, and STS. Each test was recorded using the Brower Timing Gate System, with sprint time recorded in second. All testing was completed prior to the first game of the team’s college baseball season. Offensive baseball performance measures were recorded throughout 61 regular season games. The following baseball performance data was collected from the university’s official NCAA game performance website: total stolen bases (SB), stole base attempts (AT), stolen base percentage (SBP), at bats (AB), hits (H), doubles (DB), triples (TR), homeruns (HR), runs (R), base-on-balls (BB), hit by pitch (HBP), on base percentage (OBP), slugging percentage (SLP), touched bases (TB), runs batted in (RBI), and batting average (AVE). Pearson’s product-moment correlation (p \u3c .05) was employed to examine the correlation between sprint tests and offensive baseball performance. RESULTS: The statistical analysis revealed significant correlations between STS (p = .002, r = -.762), 30 yd sprint (p = .048, r = -.556), and 60 yd sprint (p = .038, r = -.578) and SB. Additionally, a significant correlation was identified between OBP and STS (p = .022, r = -.625), 30YS (p = .027, r = -.609), and 60YS (p = .020, r = -.633). Aside from these two baseball performance metrics, 30YS and 60YS had no significant correlation with baseball performance. However, STS, additionally, significantly (p \u3c .05) correlated with AT, AB, H, TR, HR, R, BB, SLP, TB, RBI, and AVE. CONCLUSION: The STS, 30YS, and 60YS had a significant relationship with offensive baseball performance. However, the results of 30YS and 60YS only correlated with two offensive measures, while STS had a significant correlation with all but 3 offensive performance metrics. These findings suggest STS may be a more relevant measure for predicting offensive baseball performance than the traditional 30YS and 60YS tests

Modern features of VATS treatment of spontaneous pneumothorax as a complication of bullous lung emphysema: a systematic literature review

The article presents a literature review on the VATS treatment of spontaneous pneumothorax as a complication of bullous lung emphysema. The review considers questions of etiology, diagnostics and therapeutic tactics in VATS treatment of spontaneous pneumothorax with bullous emphysema. The main target of surgeons is not only elimination of spontaneous pneumothorax, but quick exposure of lung parenchyma pathology in order to predict possible reoccurrence of spontaneous pneumothorax. Video-assisted thoracoscopy in this case is a mini-invasive, less traumatic and highly efficient method of treatment of spontaneous pneumothorax. Anti-relapsing surgical interventions with pleurodesis are unanimously considered to be necessary. An integrated and differentiated approach to the treatment of spontaneous pneumothorax as a result of bullous emphysema helps to determine diagnostic and therapeutic tactics of VATS treatment and choice of pleurodesis induction leading to improved treatment outcomes in this category of patients

DYNAMICS OF THE VITALITY OF CENOPOPULATIONS OF HOLOSTEUM GLUTINOSUM (M. BIEB.) FISCH. & C.A. MEY. (CARYOPHYLLACEAE) IN THE ECOTONE SYSTEM “WATER-LAND” OF THE COAST OF THE CHOGRAI RESERVOIR

Background. The assessment of the structure of cenopopulations of early spring juveniles can be used during the organization of biological monitoring at the population level. Such information is also applicable in assessing the situation in coastal ecosystems, for forecasting and reducing the risk of their violations. Purpose. Analysis of the viability of Holosteum glutinosum cenopopulations to characterize their stability in plant communities of the “water-land” ecotone system of the coast of the Chograi reservoir. Materials and methods. The studies were carried out in the growing seasons of 2018, 2019 and 2021 in five coenopopulations of H. glutinosum growing in plant communities located in the structural blocks of the ecotone. The vital spectrum of populations was obtained by the method of Yu.A. Zlobin [3, 10, 18], the vital type - using the Q criterion [3], the vitality of populations – based on the analysis of the vital index IVC [3], the degree of prosperity or depression of populations - the IQ index [4]. Results. During the four-year study period, in 5 populations of H. glutinosum, regardless of their localization in the ecotone, the value of the Q index exceeds the frequency of individuals of the lowest class of vitality, therefore they are classified as the “thriving” vital type. The value of the vitality indices for the entire period of the study is greatest in the cenopopulation No. 1, located in the fluctuation block. The first peak of the increase in vitality occurred at coenopopulation No. 1 in the fluctuation, the second – at coenopopulation No. 4 in the marginal ecotone blocks. Conclusion. The coenopopulations of H. glutinosum in the ecotone had a vital type of “thriving”. Analysis of the dynamics of vitality in the coenopopulations of H. glutinosum revealed that the conditions prevailing in the communities of fluctuation and marginal ecotone blocks provide the greatest vitality of populations No. 1 and No. 4

Wound-healing effect of polyguanidine-based hydrogel

This article present the evaluation of polyhexamethyleneguanidine hydrochloride hydrogel influence on the course of wound healing processes. Synthesis of hydrogel is based on the interaction of amino-end groups of the polymer with carbonyl compounds. The presence of significant biocidal properties of the gel-forming polymer is allowed to consider the hydrogel as a wound healing agent. Since most wound healing agents for external use are made in the form of gels, ointments, polymer-based, it was decided to use the wound healing agent "Levomekol", a gel which consists of poly (ethylene oxide) as a comparison drug. So, in terms of linear skin-muscle wound we established the pronounced wound-healing effect of a polyhexamethyleneguanidine hydrochloride hydrogel. The results of pathomorphological studies revealed that in animals of the experimental "hydrogel" group on the eighth day of the experiment, the wound was undergoing a process of rejection of the scab, the presence of mature granulation tissue and no exudate was also observed. In the comparison group, the healing process was more slow, on the eighth day of the experiment in the animal group we observed the presence of fluid under the eschar, and lower amount of mature granulation tissue. Tensiometry of the scar has shown that the strength of scar rupture in the "hydrogel" group requires 65 % more force compared to the control group, while in the group of comparison this parameter made only 48 %

Record Maximum Oscillation Frequency in C-face Epitaxial Graphene Transistors

The maximum oscillation frequency (fmax) quantifies the practical upper bound for useful circuit operation. We report here an fmax of 70 GHz in transistors using epitaxial graphene grown on the C-face of SiC. This is a significant improvement over Si-face epitaxial graphene used in the prior high frequency transistor studies, exemplifying the superior electronics potential of C-face epitaxial graphene. Careful transistor design using a high {\kappa} dielectric T-gate and self-aligned contacts, further contributed to the record-breaking fmax

Oral curcumin for Alzheimer's disease: tolerability and efficacy in a 24-week randomized, double blind, placebo-controlled study

Introduction: Curcumin is a polyphenolic compound derived from the plant Curcuma Long Lin that has been demonstrated to have antioxidant and anti-inflammatory effects as well as effects on reducing beta-amyloid aggregation. It reduces pathology in transgenic models of Alzheimer's disease (AD) and is a promising candidate for treating human AD. The purpose of the current study is to generate tolerability and preliminary clinical and biomarker efficacy data on curcumin in persons with AD. Methods: We performed a 24-week randomized, double blind, placebo-controlled study of Curcumin C3 Complex® with an open-label extension to 48 weeks. Thirty-six persons with mild-to-moderate AD were randomized to receive placebo, 2 grams/day, or 4 grams/day of oral curcumin for 24 weeks. For weeks 24 through 48, subjects that were receiving curcumin continued with the same dose, while subjects previously receiving placebo were randomized in a 1:1 ratio to 2 grams/day or 4 grams/day. The primary outcome measures were incidence of adverse events, changes in clinical laboratory tests and the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) at 24 weeks in those completing the study. Secondary outcome measures included the Neuropsychiatric Inventory (NPI), the Alzheimer's Disease Cooperative Study - Activities of Daily Living (ADCS-ADL) scale, levels of Aβ1-40 and Aβ1-42 in plasma and levels of Aβ1-42, t-tau, p-tau181 and F2-isoprostanes in cerebrospinal fluid. Plasma levels of curcumin and its metabolites up to four hours after drug administration were also measured. Results: Mean age of completers (n = 30) was 73.5 years and mean Mini-Mental Status Examination (MMSE) score was 22.5. One subject withdrew in the placebo (8%, worsened memory) and 5/24 subjects withdrew in the curcumin group (21%, 3 due to gastrointestinal symptoms). Curcumin C3 Complex® was associated with lowered hematocrit and increased glucose levels that were clinically insignificant. There were no differences between treatment groups in clinical or biomarker efficacy measures. The levels of native curcumin measured in plasma were low (7.32 ng/mL). Conclusions: Curcumin was generally well-tolerated although three subjects on curcumin withdrew due to gastrointestinal symptoms. We were unable to demonstrate clinical or biochemical evidence of efficacy of Curcumin C3 Complex® in AD in this 24-week placebo-controlled trial although preliminary data suggest limited bioavailability of this compound. Trial registration ClinicalTrials.gov Identifier: NCT00099710