221 research outputs found
KINEMATIC ANALYSIS OF DIVING BACK PIKE SOMERSAULT IN PLATFORM ACCORDING TO PLAYERS’ SKILL LEVEL
The purpose of this study was to investigate the kinematic difference in Back Pike somersault in platform diving according to players‘ skill level and to assist them to improve performances. Ten Korean diving athletes participated in this study and they were divided into skilled group (n=5) and less-skilled group (n=5) and t-test was performed to find the difference at the moment of take-off between groups. The results showed that the hip extension angle was greater and the extension velocity of knee and hip joints were faster in skilled group compared to less-skilled group. It is recommended, therefore that the flexibility training of hip joint and muscle strength training to enhance extension velocity of knee and hip joints are needed
DIFFERENCES IN TRUNK ANGLES THROUGH DIFFERENT SHOOTING DIRECTIONS IN WATER POLO PENALTY SHOOTING
The purpose of this study was to investigate three-dimensionally the shooter’s trunk motion through 4 different shooting directions. Ten Korean national level water polo players who are right-handed were participated in this study (age, 21.60±3.20 years; weight, 86.30±8.86 kg; height, 1.83±0.05 m). To analyze the shooter’s trunk motion among different target, a three-dimensional motion analysis with six video cameras was performed.The analysis events were coking when the trunk was externally rotated maximally and release moment. A one-way ANOVA with repeated measure was performed as main statistical tests and Bonferroni correction was used as a post-hoc test. The results showed that there was statistically significant difference in trunk angle between left and right shooting directions. Especially, the posterior leaning and external rotation angles of trunk in cocking moment were bigger in left shooting direction compared to right one (p\u3c.05). These results suggest that goalkeepers predict shooting direction more precisely by identifying the trunk posture at coking moment
Association of timed up and go test outcomes with future incidence of cardiovascular disease and mortality in adults aged 66 years: Korean national representative longitudinal study over 5.7 years
The timed up and go test (TUG) is one of the most widely used tests of mobility. We aimed to examine whether the TUG is associated with cardiovascular (CV) events, CV mortality, and all-cause mortality.
Subjects in the senior cohort database of the Korean National Health Insurance Service (2002–2013) who completed the TUG as part of the National Screening Program for Transitional Ages (NSPTA) during 2007–2008 were identified. An abnormal TUG result was defined as a time ≥ 10 s. Cox proportional hazard models were used to assess the associations between TUG results and CV events, CV mortality, and all-cause mortality.
The mean follow-up period was 5.7 years. Incidence rates of CV events in the normal and abnormal TUG groups were 7.93 and 8.98 per 1000 person-years, while CV mortality rates were 0.96 and 1.51 per 1000 person-years, respectively. In a fully adjusted model, we found that abnormal TUG results were not associated with the incidences of CV events and CV mortality. However, abnormal TUG results (≥10 s) resulted in a 2.9-fold increase in CV mortality in women (adjusted hazard ratio 2.90, 95% confidence interval 1.15–7.30). Further, participants lacking certain CV risk factors, such as current cigarette smoking, obesity, or diabetes, had a higher CV mortality rate when TUG results were abnormal.
Abnormal TUG results in subjects aged 66 years were associated with future CV mortality in women and in subjects without obesity, diabetes, or cigarette smoking. In patient with mobility impairment, physicians should consider CV disease risk, especially in women.This study was supported by the Hammi Group [0620140890 (2013–2607)],
Seoul, Korea. The funder had no role in the design or conduct of the stud
Favorable response to doxorubicin combination chemotherapy does not yield good clinical outcome in patients with metastatic breast cancer with triple-negative phenotype
<p>Abstract</p> <p>Background</p> <p>We analyzed the responses to first line treatment and clinical outcomes of metastatic breast cancer patients treated with palliative doxorubicin/cyclophosphamide (AC) according to molecular cancer subtype.</p> <p>Methods</p> <p>A retrospective analysis was performed for 110 metastatic breast cancer patients selected on the basis of palliative AC treatment and the availability of immunohistochemical data for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2/neu) status.</p> <p>Results</p> <p>Of the 110 patients analyzed, 71 (64.5%) were hormone receptor positive (HR+), 14 (12.7%) were HER2+, and 25 (22.7%) were triple negative (TN). There were no differences in age, stage at diagnosis, total number of cycles of palliative chemotherapy, incidence of visceral metastasis, and metastatic sites with the exception of liver among breast cancer subtypes. The overall response rates to AC were 55.9% for the HR+ subgroup, 42.9% for the HER2+ subgroup, and 56.5% for the TN subgroup. The progression-free survival (PFS) in patients with HER2+ and TN were significantly shorter than in the HR+ (median PFS, 9.1 <it>vs </it>8.1 <it>vs </it>11.5 months, respectively; p = 0.0002). The overall survival (OS) was 25.4 months in the TN subgroup and 27.3 months in HER2+ subgroup. The median OS for these two groups was significantly shorter than for patients in the HR+ subgroup (median, 38.5 months; 95% CI, 30.1-46.9 months; p < 0.0001).</p> <p>Conclusions</p> <p>The response to palliative AC chemotherapy did not differ among breast cancer subtypes. Despite chemosensitivity for palliative AC, the TN subtype has a shorter overall survival than non-TN subtypes. Innovative treatment strategies should be developed to slow the course of disease.</p
Different contribution of extent of myocardial injury to left ventricular systolic and diastolic function in early reperfused acute myocardial infarction
BACKGROUND: We sought to investigate the influence of the extent of myocardial injury on left ventricular (LV) systolic and diastolic function in patients after reperfused acute myocardial infarction (AMI).
METHODS: Thirty-eight reperfused AMI patients underwent cardiac magnetic resonance (CMR) imaging after percutaneous coronary revascularization. The extent of myocardial edema and scarring were assessed by T2 weighted imaging and late gadolinium enhancement (LGE) imaging, respectively. Within a day of CMR, echocardiography was done. Using 2D speckle tracking analysis, LV longitudinal, circumferential strain, and twist were measured.
RESULTS: Extent of LGE were significantly correlated with LV systolic functional indices such as ejection fraction (r��=��-0.57, p��<��0.001), regional wall motion score index (r��=��0.52, p��=��0.001), and global longitudinal strain (r��=��0.56, p��<��0.001). The diastolic functional indices significantly correlated with age (r��=��-0.64, p��<��0.001), LV twist (r��=��-0.39, p��=��0.02), average non-infarcted myocardial circumferential strain (r��=��-0.52, p��=��0.001), and LV end-diastolic wall stress index (r��=��-0.47, p��=��0.003 with e') but not or weakly with extent of LGE. In multivariate analysis, age and non-infarcted myocardial circumferential strain independently correlated with diastolic functional indices rather than extent of injury.
CONCLUSIONS: In patients with timely reperfused AMI, not only extent of myocardial injury but also age and non-infarcted myocardial function were more significantly related to LV chamber diastolic function.ope
Effects of Stabilizer Thickness of 2G HTS Wire on the Design of a 1.5-MW-Class HTS Synchronous Machine
peer reviewedIn general, a metallic stabilization layer is overcoated on the outermost layer of a second-generation high-temperature superconducting (2G HTS) wire to stably transfer current against thermal and magnetic disturbances. Stabilizer thickness Ts is one of the key issues in an HTS synchronous machine (HTSSM) application because it strongly affects the electrical output performance of the machine and the stable operation and reliable protection of the HTS field coil. In this paper, a design and characteristic analysis for manufacturing a 1.5-MW-class HTSSM was performed using a 2-D analytical design code and a 3-D finite-element method. Various Ts values were considered in the HTS field-coil design to investigate their effects on the stability and protection of the HTS coil and the back-electromotive force of the machine. The design parameters are also discussed to determine suitable Ts for the 2G HTS wire
Design of Indirect Closed-Cycle Cooling Scheme Coupled with a Cryocooler for a 3-MW-Class Higherature Superconducting Synchronous Motor
peer reviewedThe increase in the heat generated from higherature superconducting (HTS) rotating components limits the applicability of a cooling method. Hence, a liquid cooling and convection cooling scheme for high-heat-flux applications has gained interest. An indirect closed-cycle cooling scheme coupled with a cryocooler is an alternative cooling technique, in which the heat of vaporization is transferred from an evaporator to a condenser with a relatively small temperature difference. The cooling system of a demonstrative 3-MW-class HTS motor is presented in this paper. A cryogen was used to maintain uniform temperature of the field coil; the maximum temperature of the HTS coils was approximately 30 K during normal operation. The operation process of the cooling system is illustrated, and the main circulation parameters, namely, cryogen flow rate and the heat flux of cooling system, are investigated
Subchronic inhalation toxicity of gold nanoparticles
<p>Abstract</p> <p>Background</p> <p>Gold nanoparticles are widely used in consumer products, including cosmetics, food packaging, beverages, toothpaste, automobiles, and lubricants. With this increase in consumer products containing gold nanoparticles, the potential for worker exposure to gold nanoparticles will also increase. Only a few studies have produced data on the <it>in vivo </it>toxicology of gold nanoparticles, meaning that the absorption, distribution, metabolism, and excretion (ADME) of gold nanoparticles remain unclear.</p> <p>Results</p> <p>The toxicity of gold nanoparticles was studied in Sprague Dawley rats by inhalation. Seven-week-old rats, weighing approximately 200 g (males) and 145 g (females), were divided into 4 groups (10 rats in each group): fresh-air control, low-dose (2.36 × 10<sup>4 </sup>particle/cm<sup>3</sup>, 0.04 μg/m<sup>3</sup>), middle-dose (2.36 × 10<sup>5 </sup>particle/cm<sup>3</sup>, 0.38 μg/m<sup>3</sup>), and high-dose (1.85 × 10<sup>6 </sup>particle/cm<sup>3</sup>, 20.02 μg/m<sup>3</sup>). The animals were exposed to gold nanoparticles (average diameter 4-5 nm) for 6 hours/day, 5 days/week, for 90-days in a whole-body inhalation chamber. In addition to mortality and clinical observations, body weight, food consumption, and lung function were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, blood samples were collected for hematology and clinical chemistry tests, and organ weights were measured. Cellular differential counts and cytotoxicity measurements, such as albumin, lactate dehydrogenase (LDH), and total protein were also monitored in a cellular bronchoalveolar lavage (BAL) fluid. Among lung function test measurements, tidal volume and minute volume showed a tendency to decrease comparing control and dose groups during the 90-days of exposure. Although no statistically significant differences were found in cellular differential counts, histopathologic examination showed minimal alveoli, an inflammatory infiltrate with a mixed cell type, and increased macrophages in the high-dose rats. Tissue distribution of gold nanoparticles showed a dose-dependent accumulation of gold in only lungs and kidneys with a gender-related difference in gold nanoparticles content in kidneys.</p> <p>Conclusions</p> <p>Lungs were the only organ in which there were dose-related changes in both male and female rats. Changes observed in lung histopathology and function in high-dose animals indicate that the highest concentration (20 μg/m<sup>3</sup>) is a LOAEL and the middle concentration (0.38 μg/m<sup>3</sup>) is a NOAEL for this study.</p
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