49 research outputs found

    THE RESEARCH ON ISOKINETIC STRENGTH TESTING OF KNEE JOINT MUSCLE OF SHI DONGPENG, THE INTERNATIONALLY MASTER OF SPORTS

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    Since over 10 years ago, there have been many reports conceming tests of muscle strength and evaluation of muscle function, both of which adopted 'Isokinetic test system. Yet, in contrast, there have been fewer reports devoted to analysis and research on individual athletes. With Kinitech system, this paper will test and evaluate the knee joint muscle of Shi Dongpeng, the internationally top-notch 110m hurdle athlete, using the following 3 indexes: Relative Peak Torque (PT/SW), Time to Peak Torque (TPT) and Flexors/Extensors Values (FIE). And all the 3 indexes will be correspondingly contrasted with those of common young men's knee joint muscle. And the purpose of this paper is to prOVide scientific referent basis for the athlete to choose suitable training ways, to have specific strength training and to have great achievement

    THE EFFECTS OF STATIC STRETCHING AFTER STRENUOUS TRAINING ON ULTRASTRUCTURE AND FLEXIBILITY OF RATS' GASTROCNEMIUS

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    The purpose of the present study was to investigate effects of static stretching after strenuous training on the ultrastructure and flexibility of rats' gastrocnemius. 24 male Sprague-Dawley rats were randomly divided into three groups: normal control (NC), training control(TC) and stretching group(ST). The results were as follows: 1) The myofilaments became supercontracted and Z discs were obscure in TC. On the contrary, the myofilaments arranged orderly and the Z lines were clear and the mitochondrial cristas were manifolded in ST. 2) Compared with NC, the ultimate tensile strength of gastrocnemius was increased in TC, while the Max. deformation of gastorcnemius was decreased. However, the Max. deformation in ST was increased than that of NC. The conclusion was that the ultrastructure of muscle was resumed and the ability of distortion and flexibility was improved by static stretching, which decreased the risk of injury

    THE RESEARCH ACTUALITY AND DEVELOPING TREND OF SPORTS BIOMECHANICS IN CHINA

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    From the 20th century to 21st century, the human all knowledge of the class got fast development. And sports biomechanics is one of the disciplines with the fastest developing speed. The elite of the numerous researchers of the set participates in studying in short 30 years, with rigorous scientific attitude initiative application many kinds of theory of discipline they, and the most advanced instrument studied the method, thought deeply and carefully about this discipline at that time, promote the development of sports biomechanics actively. This research course itself whether one method study, it is one that makes development history that people revere

    A STUDY OF THE RATE OF TORQUE BETWEEN UPPER AND LOWER LIMBS OF MALE SPRINTERS

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    In order evaluate the level in their strength development and to study the appropriate rate of torque among muscles at each joint so as to design criterion scientifically evaluating the magnitude of force, we assigned the sUbjects to four groups: male children (CHIL), male juveniles (JUVE), male juvenile sprinters from sports training school (JSTS), and young sprinters (YOSP). The flexors and extensor strength of their hip, knee, and shoulder joint are measured by an isokinetic test system. It is indicated in the result of the experiment the rate between high-speed strength and absolute strength of left and right knee extensors was lower than that of flexors. We have calculated and compared the relative torques of hip, knee, shoulder joint at the velocity of 600 /s using the relative peak torque of hip joint. Compared with CHIL, there was a significant increase in the knee average rate than that of shoulder in YOSP

    GC-MS STUDY OF THE REMOVAL OF DISSOLVED AND COLLOIDAL SUBSTANCES IN RECYCLED PAPERMAKING BY FLOCCULATION WITH NANO-SIZE TIO2 COLLOIDS

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    In the papermaking process, the removal and control of dissolved and colloidal substances (DCS) is a key issue for reducing the usage of fresh water. Nano-size TiO2 is an excellent capturing and flocculating agent for DCS due to its large surface area and positive charge. The composition of dissolved and colloidal substances in a system and the removal of these substances by flocculation with nano-size TiO2 colloids were determined by gas chromatography and mass spectrometry (GC-MS). The samples were obtained from non-deinked pulp (non-DIP), deinked pulp (DIP), and whitewater. The research results indicated that the removal efficiencies of the DCS, which are associated with the molecular structures, were sequenced from large to small as follows: resin acids and sterols, benzene derivatives containing carboxyl, fatty acids, and the phthalic acid esters. Then, the mechanism of flocculation removal of DCS was considered. With hydrogen bonding between the surface hydroxyl (Ti4+-OH) and the functional groups containing oxygen, the nano-size TiO2 particles can capture dissolved substances (DS), and bridge colloidal substances (CS) and complexes to induce agglomerate flocculation. The flocculating removal efficiencies were influenced by the functional groups and alkyls of the DCS. Greater numbers and polarities of functional groups produced higher removal efficiencies. Long alkyl chains shield functional groups, thereby inhibiting the formation of hydrogen bonding, which results in a decrease in removal efficiencies

    Double-Positive CD21+CD27+ B Cells Are Highly Proliferating Memory Cells and Their Distribution Differs in Mucosal and Peripheral Tissues

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    Several B-cell defects arise in HIV infected patients, particularly in patients with chronic infection and high viral load. Loss of memory B cells (CD27(+) B cells) in peripheral blood and lymphoid tissues is one of the major B cell dysfunctions in HIV and simian immunodeficiency virus (SIV) infection. Despite several studies, definitive identification of memory B cells based on CD27 surface expression has not been described. Similarly, the rates of cell turnover in different B cell subpopulation from lymphoid and mucosal tissues have not been well documented. In this study, we demonstrate the presence of memory B cell populations and define their distribution, frequency and immunophenotype with regards to activation, proliferation, maturation, and antibody production in normal rhesus macaques from different lymphoid tissues.Thirteen healthy, uninfected rhesus macaques were selected for this study. CD20(+) B cells were isolated from peripheral blood and sorted based on CD27 and CD21 surface markers to define memory B cell population. All the B cell subpopulation was further characterized phenotypically and their cell turnover rates were evaluated in vivo following bromodeoxyuridine (BrdU) inoculation. Double positive (DP) CD21(+)CD27(+) B cells in both peripheral and lymphoid tissues are memory B cells, able to produce antibody by polyclonal activation, and without T cell help. Peripheral and lymphoid DP CD21(+)CD27(+) B cells were also able to become activated and proliferate at higher rates than other B cell subpopulations. Increased turnover of tonsillar memory B cells were identified compared to other tissues examined.We suggest that this DP memory B cells play a major role in the immune system and their function and proliferation might have an important role in HIV/SIV mediated B cell dysregulation and pathogenesis

    Improved Model for Brightness Optimization Control in the First (C95/D5) Bleaching Stage

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    In the first stage of pulp bleaching, the quantity of added chemicals (ClO2 and/or Cl2) is commonly controlled by kappa factor, based on a kappa number online analyzer together with a compensated brightness control scheme as a feedback strategy. However, a kappa number analyzer is not always available, so the bleaching quality relies heavily on the chemical dosage set-point chosen by the operators. In this study, an improved model for the chlorination stage brightness optimization was proposed, based on brightness and residual chemicals before pulp enters the bleaching tower. Additionally, the experience of operators of (C95/D5) bleaching was employed in order to find an optimum chemical dosage set-point quickly. The golden section search algorithm (i.e., β€˜0.618 method’) was used to find the optimum chemical dosage in this paper. After applying the proposed method in a pulp mill (C95/D5) bleaching stage, the chlorination stage brightness shifted from 62.9% ISO to the target value 60.7% ISO. Meanwhile, the standard deviation was reduced from 3.0 to 2.5
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