LAWS AND CHARACTERISTICS OF THROWING POWER CHANGES FOR DIFFERENT WOMEN DISCUS THROWERS

Throwing power means that rate of muscle do work when throwers do throwing movements. It depends on strength and speed of throwers. It is a sensitive index to mirror explosive force and fast strength Tl1is paper adopts experiment and video analysis methods. The purpose was to research the laws and characteristics of throwing power changes for different women’s discus throwers through measuring results of throwing various weights to deferent Chinese women’s discus throwers (master:55m, n1=13; first grade: 51m, n2=17; second grade: 39m, n3=30). The results show that following: 1.Throwing weight of women[s discus throwers is closely related to throwing power. With increasing of the weight, the power also raise gradually (r1 =0. 905, r2= o 862, r3=0.900) But when the weight comes up to a certain extent, the power not only don’t raise but also reduce obviously if the weight is continued increasing (r1 =0.996, r2=-0.964, r3= -0.933). It is various that different women’s discus throwers show the greatest throwing power and its corresponding throwing weight. Generally speaking, the higher thrower’s performance level is, the greater the greatest throwing power and its corresponding throwing weight show. Even if the level of throwers is same, the weight of the greatest throwing power is not completely sam

Weak current phenomenon in stressed coal and its prospective applications in early warning for coal and rock dynamic disasters

In this study, some loading experiments were conducted on coal specimens using the established weak current testing system to investigate the effects of weak currents in coals. The response characteristics of weak currents during the coal deformation process were analyzed, and a quantitative relationship between weak currents and the mechanical behaviors of coal was established. The principles for predicting coal and rock dynamic disasters based on the weak current method were proposed. Furthermore, drawing upon the results obtained from on-site practical applications, a forward-looking assessment of the potential applications of this methodology is presented. The results indicate that the deformation of loaded coal generates weak currents. The fluctuations in these weak currents exhibit a notable alignment with variations in stress, with the magnitude closely tied to the coal mechanical characteristics like stress, strain, and strain rate. Notably, in the compaction and plastic deformation stages, the weak current rises in tandem with the strain rate, while in the elastic deformation stage, the weak current exhibits a linear increase in correlation with stress and strain. Under perturbation loading, the coal produces some periodic weak currents, referred to as the pulsating direct current (PDC). And the variations in the PDC align with stress changes. Furthermore, the weak current demonstrates a reliable precursor response to coal damage, with some unusual fluctuations observed during the accelerated increase process (plastic deformation stage) serving as the precursor indicators for the progressive failure of coal. Conversely, the pulse-like fluctuations observed during the attenuation process can be regarded as the precursor features for the coal's creep failure. The phenomenon of weak currents in stressed coal serves as a pivotal foundation for conducting weak current measurements in mines. The intimate correlation between weak currents and the mechanical behaviors of coal underscores a crucial prerequisite for employing the weak current technology in monitoring stress within coal and rock formations. Furthermore, the discernible precursor response of weak currents to coal damage provides a vital assurance for predicting coal and rock dynamic disasters through the utilization of weak current technology. The weak current technology possesses some advantages such as high responsiveness, clear precursor signals, and robust anti-interference capabilities. These attributes make it highly promising for some applications in the stress monitoring within coal/rock mass and the early warning for coal and rock dynamic disasters. In the future, some further researches on the fundamental theory and applied technology of weak current in stressed coal and rock are needed to provide a support for the development of precise spatiotemporal monitoring and early warning of coal rock dynamic disasters using the weak current methods

Stick-slip meta-instability of coal under uniaxial loading and AE and EMR response characteristics

Meta-instability stage is the most abundant precursory information and the most intense change stage in the process of fault stick-slip instability. In order to deeply explore the characteristics of coal meta-instability and the response law of acoustic and electrical signals in this process, the uniaxial graded loading experiments of coal samples with different prefabricated crack angles were carried out. The internal fracture source location, surface displacement field, acoustic emission and electromagnetic radiation signals of the samples were synchronously collected, and the mechanical behavior and acoustic and electrical characteristics of coal meta-instability were analyzed. The results show that: ① The inclination angle of the prefabricated crack significantly affects the internal stress distribution of the loaded coal sample, and even the expansion distribution of the new cracks in the meta-instability stage. The acoustic emission count and energy have obvious responses to stress and failure. When the meta-instability is near, the acoustic emission count and energy increase sharply at the same time, and the signal proportion is close to 20%. The response characteristics can be used as the basis for judging the crack coal sample entering the meta-instability stage. ② After entering the meta-instability state, the electromagnetic radiation activity is the most intense, which is almost consistent with the occurrence time of stress drop. Before the main fracture occurs, the energy and amplitude of electromagnetic radiation increase sharply, and the peak energy increases first and then decreases with the increase of crack dip angle. When the crack dip angle is 45°, the electromagnetic radiation count accounts for the largest proportion of the total instability process. ③ The fracture profile of the coal sample in the meta-instability stage has been basically formed. The inclination angle of the prefabricated crack has a significant impact on the duration of the meta-instability stage of the coal sample. When the inclination angle is 45°, the duration of the meta-instability stage is the longest, and when the inclination angle is 60°, the duration proportion is the shortest. The research results can be used to formulate the monitoring scheme of fault meta-instability, and the evolution and disaster of large-scale rock burst in fault structural are

On the mechanism of the cyclonic circulation in the Gulf of Tonkin in the summer

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C09029, doi:10.1029/2007JC004208.The circulation in the Gulf of Tonkin had been traditionally considered to be anticyclonic in the summer. This view was challenged recently by results from reanalyzing observational data, which clearly revealed that the circulation is cyclonic in all seasons. The surface wind stress is monsoonal, southwesterly in the summer and reversed in the winter. It remains unexplained why the circulation is always cyclonic, while the surface forcing reverses seasonally. In this study, we hypothesize that the inflow through Qiongzhou Strait, a shallow and narrow channel between Hainan Island and the Chinese mainland, is responsible for maintaining the cyclonic circulation in the summer. Besides the requirements of mass conservation and bathymetry constraint, this flow, even with a rather small transport, carries a considerable amount of potential vorticity (PV) into the gulf, and the integral constraint of PV requires the presence of a frictional torque to be associated with a cyclonic circulation. Several numerical experiments with a three-dimensional model have been conducted to test this hypothesis. When the westward flow through Qiongzhou Strait is blocked, the model simulates an anticyclonic circulation in the summer. When the westward flow through Qiongzhou Strait is allowed, the circulation changes to a cyclonic one, consistent with our hypothesis.This study is supported by the National Basic Research Program of China under contract 2005CB422302 and 2007CB411804, the key project of the International Science and Technology Cooperation program of China under contract 2006DFB21250, and the 111 project under contract B07036

Automatic nodule identification and differentiation in ultrasound videos to facilitate per-nodule examination

Ultrasound is a vital diagnostic technique in health screening, with the advantages of non-invasive, cost-effective, and radiation free, and therefore is widely applied in the diagnosis of nodules. However, it relies heavily on the expertise and clinical experience of the sonographer. In ultrasound images, a single nodule might present heterogeneous appearances in different cross-sectional views which makes it hard to perform per-nodule examination. Sonographers usually discriminate different nodules by examining the nodule features and the surrounding structures like gland and duct, which is cumbersome and time-consuming. To address this problem, we collected hundreds of breast ultrasound videos and built a nodule reidentification system that consists of two parts: an extractor based on the deep learning model that can extract feature vectors from the input video clips and a real-time clustering algorithm that automatically groups feature vectors by nodules. The system obtains satisfactory results and exhibits the capability to differentiate ultrasound videos. As far as we know, it's the first attempt to apply re-identification technique in the ultrasonic field

Phosphorylated ERK is a potential predictor of sensitivity to sorafenib when treating hepatocellular carcinoma: evidence from an in vitro study

<p>Abstract</p> <p>Background</p> <p>Sorafenib is the first agent that has demonstrated an improved overall survival benefit in advanced hepatocellular carcinoma (HCC), setting a new standard for first-line treatment. However, no one has yet been able to predict sensitivity to sorafenib. Pre-treatment pERK level has been shown to be associated with favorable response to such therapy in a phase II clinical study, indicating that pERK may be a potential biomarker for treatment of HCC with sorafenib.</p> <p>Methods</p> <p>The effects of sorafenib and 5-fluorouracil (5-FU) on cell proliferation were evaluated by cell viability assays in four HCC cell lines (SMMC-7721, MHCC97-L, MHCC97-H and HCCLM6) with different metastatic potential and basal pERK expression levels. Expression levels of pERK were determined by immunocytochemical quantification together with western blot analysis, and pERK density values were also calculated. Correlation analyses were then carried out between the IC₅₀values of drugs and pERK density values. After basal ERK phosphorylation was down-regulated with U0126 in MHCC97-H cells, cellular responsiveness to sorafenib was assessed by cell viability assay.</p> <p>Results</p> <p>Basal pERK levels increased stepwise in cell lines in accordance with their metastatic potential. Sorafenib inhibited ERK phosphorylation in a dose-dependent manner in all four cell lines at a concentration between 5 and 20 μM, but the degree of inhibition was significantly different according to their basal pERK expression level (<it>P </it>< 0.0001). In contrast, no significant change was observed after 5-FU treatment. Correlation analyses between the IC₅₀values and pERK densities revealed that the effects of sorafenib on cell proliferation were significantly correlated with basal pERK levels (Spearman r = -0.8671, <it>P </it>= 0.0003). Resistance to 5-FU was also significantly associated with basal pERK expression in these HCC cell lines (Spearman r = 0.7832, <it>P </it>= 0.0026). After the basal ERK phosphorylation level in MHCC97-H cells was reduced with U0126, they were significantly less sensitive to sorafenib-mediated growth inhibition, with an IC₅₀of 17.31 ± 1.62 μM versus 10.81 ± 1.24 μM (<it>P </it>= 0.0281).</p> <p>Conclusion</p> <p>In this <it>in vitro </it>study, pERK was confirmed to be a potential biomarker predictive of sensitivity to sorafenib in treating HCC. The RAF/MEK/ERK pathway may be involved in drug resistance to traditional chemotherapy in HCC.</p

Prevalence of Depression in Older Nursing Home Residents in High and Low Altitude Regions: A Comparative Study

Objective: Depressive symptoms (depression hereafter) is common in older adults, and closely associated with environmental factors. This study compared the prevalence of depression in older adults living in high-altitude and low-altitude regions, and their association with quality of life (QOL).Method: A total of 632 older nursing home residents were included, with 425 participants living in low-altitude and 207 participants living in high-altitude regions. Depression and QOL were assessed using standardized instruments.Results: The prevalence of depression was 26.9% (95% CI: 23.43–30.37%) in the whole sample of older nursing home residents, with 11.1% (95% CI: 8.01–14.05%) in those living in low-altitude and 59.4% (95% CI: 52.68–66.17%) in those living in high-altitude regions. Multiple logistic regression analysis revealed that living in low-altitude region (P &lt; 0.001, OR = 0.07, 95% CI: 0.04–0.12) was associated with lower risk of depression, while perception of poor health status (P &lt; 0.001, OR = 3.86, 95% CI: 1.98–7.54) and having insomnia (P &lt; 0.001, OR = 4.76, 95% CI: 2.99–7.56) were associated with higher risk of depression. QOL was significantly lower in physical (F(1,632) = 35.421, P &lt; 0.001), psychological (F(1,632) = 20.777, P &lt; 0.001), social (F(1,632) = 8.169, P &lt; 0.001) and environmental domains (F(1,632) = 11.861, P &lt; 0.001) in those with depression.Conclusion: Depression was common in older nursing home residents especially those living in the high-altitude region. Considering the negative impact of depression on QOL and functional outcomes, routine screening and timely treatment of depression should be implemented in this population

Model-based estimate of the heat budget in the East China Sea

Using a global ocean model with regionally focused high resolution (1/10°) in the East China Sea (ECS), we studied the oceanic heat budget in the ECS. The modeled sea surface height variability and eddy kinetic energy are consistent with those derived from satellite altimetry. Significant levels of eddy kinetic energy are found east of the Ryukyu Islands and east of Taiwan, where the short-term variability is spawned by active mesoscale eddies coalescing with the circulation. Furthermore, the simulated vertical cross-stream structure of the Kuroshio (along the Pollution Nagasaki line) and the volume transport through each channel in the ECS are in good agreement with the observational estimates. The time-averaged temperature fluxes across the Taiwan Strait (TWS), Tsushima Strait (TSS), and the 200 m isobath between Taiwan and Japan are 0.20 PW, 0.21 PW, and 0.05 PW, respectively. The residual heat flux of 0.04 PW into the ECS is balanced by the surface heat loss. The eddy temperature flux across the 200 m isobath is 0.005 PW, which accounts for 11.2% of the total temperature flux. The Kuroshio onshore temperature flux has two major sources: the Kuroshio intrusion northeast of Taiwan and southwest of Kyushu. The Ekman temperature flux induced by the wind stress in the ECS shows the same seasonal cycle and amplitude as the onshore temperature flux, with a maximum in autumn and a minimum in summer. We conclude that the Ekman temperature flux dominates the seasonal cycle of Kuroshio onshore flux

An analysis of farmers' perception of the new cooperative medical system in Liaoning Province, China

<p>Abstract</p> <p>Background</p> <p>Since 2003, the number of pilot areas of the New Rural Cooperative Medical System (NRCMS) has increased in rural China. And the major efforts have been concentrated on the enrollment of prospective members. In this study, we examined the satisfaction of the rural residents with the NRCMS as well as factors affecting their attitudes towards the NRCMS.</p> <p>Methods</p> <p>The data for this study were collected from a survey involving twenty counties in Liaoning Province. Interviews and focus groups were conducted between 10^thJanuary and 20^thAugust 2008. A total of 2,780 people aged 18-72 were randomly selected and interviewed. Data were evaluated by nonparametric tests and ordinal regression models.</p> <p>Results</p> <p>71.6% of the study subjects were satisfied with the NRCMS. Single factor analysis showed that attitudes towards the NRCMS were influenced by gender, age, marital status, and self-rated health status. In the ordinal regression analysis, gender, age, and self-rated health status affect satisfaction (P < 0.05).</p> <p>Conclusions</p> <p>We found that a considerable proportion of farmers were satisfied with the NRCMS. Gender, age, and self-rated health status had significant effects on farmers' attitudes towards the NRCMS. The Chinese Central Government attempted to adopt active measures in the future to continuously improve the NRCMS, including initiating educational programs, building new medical facilities and increasing financial investment.</p

Prevalence of primary biliary cirrhosis in adults referring hospital for annual health check-up in Southern China

<p>Abstract</p> <p>Background</p> <p>Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by the presence of anti-mitocondrial autoantibodies (AMA) which has an essential role also for diagnosis. In addition, also some anti-nuclear antibodies (ANA) have been shown to be highly specific PBC. The purpose of this study was to assess the prevalence of PBC among the adults referring hospital for annual health check-up in Southern China by screening sera for PBC-specific autoantibodies.</p> <p>Methods</p> <p>AMA and ANA were screened in 8,126 adults (mean age 44 ± 15 years, 48% females) by indirect immunofluorenscence (IIF). Positive sera were tested by ELISA/immunoblotting for AMA-M2, anti-sp100 and anti-gp210. A diagnosis of PBC was re-assessed six months after the initial testing.</p> <p>Results</p> <p>Out of 8,126 individuals 35 were positive for AMA and 79 positive for ANA. Nineteen, 4, and 3 of the subjects positive for AMA and/or ANA showed reactivity for AMA-M2, anti-sp100 or gp210, respectively, further tested with ELISA/immunoblotting. Fourteen in the 39 individuals positive for AMA at IIF, AMA-M2, anti-gp210, or anti-sp100 had abnormal cholestatic liver functional indices. One definite and 3 probable PBC diagnosis could be made in 4 cases including 3 females and 1 male after half a year.</p> <p>Conclusions</p> <p>We found a point prevalence rate of PBC among Southern Chinese adults attending for yearly health check-up of 492 cases per million (95% CI, 128 to 1,093) and 1,558 cases per million (95% CI, 294 to 3,815) for women over 40, a finding similar to prevalence reported in other geographical areas.</p