DOSE FASTER HOPPING FREQUENCY IMPROVE RESPONSE TIME AND KICKING SPEED IN TAEKWONDO ROUNDHOUSE KICK?

The purpose of this study was to investigate the effect of rhythmic hopping frequency on the response time and kicking speeds in Taekwondo roundhouse kick. Eleven elementary and middle-school athletes voluntarily participated in this study. They performed five roundhouse kicks at three different hopping frequencies (normal, 15% faster than normal, and 15% slower than normal) and no hop condition. Results indicated that the 15% slower hopping frequency induced a significantly longer response time than the 15% faster frequency. The 15% faster frequency resulted in faster maximum kicking speed than normal frequency did, while there was no difference in contact kicking speed. Partially the faster hopping frequency would be beneficial to kicking performance

Adult-onset kaposiform hemangioendothelioma with neurofibromatosis type 1: A case report and literature review

Kaposiform hemangioendothelioma (KHE) is a very rare, locally aggressive vascular neoplasm. It occurs mostly in children and is rarely observed in adults. It typically originates on the skin, later affecting the deep soft tissue of the extremities, head or neck, and retroperitoneum by infiltrative growth. It is locally aggressive, does not regress spontaneously, and tends to metastasize locally as well as to the regional lymph nodes. In this article, we report a case of adult-onset KHE with neurofibromatosis type 1. The patient presented to our department with a 2-month history of a painful ulceration in her left popliteal area. Since KHE had not previously been reported in patients with neurofibromatosis, the diagnosis was difficult due to the similarity of the skin manifestation to neurofibromatosis-associated lesions. We share our experience of diagnosing and treating this rare case of adult-onset KHE

A modified formula using energy system contributions to calculate pure maximal rate of lactate accumulation during a maximal sprint cycling test

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate (νLa.max) and a modified formula of pure νLa.max (PνLa.max) during a 15-s all-out sprint cycling test (ASCT) to analyze their relationships.Methods: Thirty male national-level track cyclists participated in this study (n = 30) and performed a 15-s ASCT. The anaerobic power output (Wpeak and Wmean), oxygen uptake, and blood lactate concentrations (La−) were measured. These parameters were used for different calculations of νLa.max and three energy contributions (phosphagen, WPCr; glycolytic, WGly; and oxidative, WOxi). The PνLa.max calculation considered delta La−, time until Wpeak (tPCr−peak), and the time contributed by the oxidative system (tOxi). Other νLa.max levels without tOxi were calculated using decreasing time by 3.5% from Wpeak (tPCr −3.5%) and tPCr−peak.Results: The absolute and relative WPCr were higher than WGly and WOxi (p < 0.0001, respectively), and the absolute and relative WGly were significantly higher than WOxi (p < 0.0001, respectively); νLa.max (tPCr −3.5%) was significantly higher than PνLa.max and νLa.max (tPCr−peak), while νLa.max (tPCr−peak) was lower than PνLa.max (p < 0.0001, respectively). PνLa.max and νLa.max (tPCr−peak) were highly correlated (r = 0.99; R2 = 0.98). This correlation was higher than the relationship between PνLa.max and νLa.max (tPCr −3.5%) (r = 0.87; R2 = 0.77). νLa.max (tPCr−peak), PνLa.max, and νLa.max (tPCr −3.5%) were found to correlate with absolute Wmean and WGly.Conclusion: PνLa.max as a modified calculation of νLa.max provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than νLa.max (tPCr−peak) and νLa.max (tPCr −3.5%). Because WOxi and WPCr can differ remarkably between athletes, implementing their values in PνLa.max can establish more optimized individual profiling for elite track cyclists

Risk factors for deaths associated with COVID-19 according to the cause of death classification in Republic of Korea

Objectives This study aimed to classify coronavirus disease 2019 (COVID-19)-related deaths according to whether COVID-19 was listed as the cause of death, and to investigate the differences in demographic characteristics and risk factors for COVID-19 death classifications. Methods A total of 5,625 deaths in South Korea among patients with confirmed COVID-19 from January 20, 2020 to December 31, 2021 were selected. Excluding false reports and unnatural deaths, 5,597 deaths were analyzed. Based on death report data, deaths were classified according to whether the cause of death was listed as COVID-19 (CD) or not (NCD). The epidemiological characteristics and causes of deaths were investigated using descriptive, univariate, and multivariate statistical analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to analyze the risk factors. Results The case fatality ratio was 0.89% and increased with age. Additionally, 96.4% of the subjects had an underlying disease, and 53.4% died in winter. The proportion of NCDs was 9.3%, of whom 19.1% died at home and 39.0% were confirmed to have COVID-19 after death. Malignant neoplasms (102/416 vs. 637/4,442; OR, 1.71; 95% CI, 1.36−2.16; p<0.001) were significantly associated with NCD. Conclusion This is the first study to analyze risk factors by cause of death using COVID-19 death report data in South Korea. These results are expected to be used as evidence for establishing a death monitoring system that can collect timely information in a new infectious disease pandemic

Atomic arrangement of van der Waals heterostructures using X-ray scattering and crystal truncation rod analysis

Vanadium diselenide (VSe2) has intriguing physical properties such as unexpected ferromagnetism at the two-dimensional limit. However, the experimental results for room temperature ferromagnetism are still controversial and depend on the detailed crystal structure and stoichiometry. Here we introduce crystal truncation rod (CTR) analysis to investigate the atomic arrangement of bilayer VSe2 and bilayer graphene (BLG) hetero-structures grown on a 6H-SiC(0001) substrate. Using non-destructive CTR analysis, we were able to obtain electron density profiles and detailed crystal structure of the VSe2/BLG heterostructures. Specifically, the out-of-plane lattice parameters of each VSe2 layer were modulated by the interface compared to that of the bulk VSe2 1T phase. The atomic arrangement of the VSe2/BLG heterostructure provides deeper understanding and insight for elucidating the magnetic properties of the van der Waals heterostructure.Comment: 17 pages, 4 figure

Novel biomarker-based model for the prediction of sorafenib response and overall survival in advanced hepatocellular carcinoma: a prospective cohort study

Background Prediction of the outcome of sorafenib therapy using biomarkers is an unmet clinical need in patients with advanced hepatocellular carcinoma (HCC). The aim was to develop and validate a biomarker-based model for predicting sorafenib response and overall survival (OS). Methods This prospective cohort study included 124 consecutive HCC patients (44 with disease control, 80 with progression) with Child-Pugh class A liver function, who received sorafenib. Potential serum biomarkers (namely, hepatocyte growth factor [HGF], fibroblast growth factor [FGF], vascular endothelial growth factor receptor-1, CD117, and angiopoietin-2) were tested. After identifying independent predictors of tumor response, a risk scoring system for predicting OS was developed and 3-fold internal validation was conducted. Results A risk scoring system was developed with six covariates: etiology, platelet count, Barcelona Clinic Liver Cancer stage, protein induced by vitamin K absence-II, HGF, and FGF. When patients were stratified into low-risk (score ≤ 5), intermediate-risk (score 6), and high-risk (score ≥ 7) groups, the model provided good discriminant functions on tumor response (concordance [c]-index, 0.884) and 12-month survival (area under the curve [AUC], 0.825). The median OS was 19.0, 11.2, and 6.1 months in the low-, intermediate-, and high-risk group, respectively (P  0.05 between expected and observed values). Conclusions This new model including serum FGF and HGF showed good performance in predicting the response to sorafenib and survival in patients with advanced HCC.This work was funded by Doosan Yonkang Foundation (Grant No. 30–2016-0240), Liver Research Foundation of Korea as part of Bio Future Strategies Research Project, and Ewha Womans University research grant (2016). The funding bodies had no role in the design of the study, collection, analysis, and interpretation of data and in writing of the manuscript