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Maximum Strength (maximum + strength)

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Medical Sciences75%

Selected Abstracts

Coagulation dynamics and platelet functions in obstructive jaundiced patients

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2009
Tebessüm Çak
Abstract Background:, All of the body systems are affected by increased levels of bilirubin. The aim of this study is to investigate the function of platelets and clotting dynamics in patients with obstructive jaundice. Methods:, Liver function tests, serum CRP, PT, PTT and hemogram were measured in 23 patients with obstructive jaundice. Thromboelastography (TEG) was done for the evaluation of coagulation dynamics, while platelet function assay (PFA 100) was used to evaluate platelet functions. Blood samples were obtained at two occasions, before the drainage and 3 weeks after the relief of the obstruction. Results:, Hypercoagulation was detected in 80% of patients. Maximum strength, elasticity, coagulation indices of the clot were correlated with increased concentrations of direct bilirubin. Although maximum strength of coagulum usually represents increased activity of platelet function, membrane closure times with PFA 100 were found to be prolonged in 30% of patients, reduced values were determined in 17% of patients. No demonstrable effect on coagulation parameters and platelet function were detected after drainage procedures regardless of modality. Conclusions:, Even though there is a general assumption about the increased bleeding tendency in obstructive jaundiced patients, we could not demonstrate reduced clotting activity by measuring with either PFA or TEG. On the contrary we observed tendency for hypercoagulation independent of increased prothrombin times. The most probable cause of this effect is the increased activity of fibrin polymers on platelet membrane. [source]

On double shearing in frictional materials

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 1 2007
J. A. M. Teunissen
Abstract This paper evaluates the mechanical behaviour of yielding frictional geomaterials. The general Double Shearing model describes this behaviour. Non-coaxiality of stress and plastic strain increments for plane strain conditions forms an important part of this model. The model is based on a micro-mechanical and macro-mechanical formulation. The stress,dilatancy theory in the model combines the mechanical behaviour on both scales. It is shown that the general Double Shearing formulation comprises other Double Shearing models. These models differ in the relation between the mobilized friction and dilatancy and in non-coaxiality. In order to describe reversible and irreversible deformations the general Double Shearing model is extended with elasticity. The failure of soil masses is controlled by shear mechanisms. These shear mechanisms are determined by the conditions along the shear band. The shear stress ratio of a shear band depends on the orientation of the stress in the shear band. There is a difference between the peak strength and the residual strength in the shear band. While peak stress depends on strength properties only, the residual strength depends upon the yield conditions and the plastic deformation mechanisms and is generally considerably lower than the maximum strength. It is shown that non-coaxial models give non-unique solutions for the shear stress ratio on the shear band. The Double Shearing model is applied to various failure problems of soils such as the direct simple shear test, the biaxial test, infinite slopes, interfaces and for the calculation of the undrained shear strength. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Coagulation dynamics and platelet functions in obstructive jaundiced patients

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2009
Tebessüm Çak
Abstract Background:, All of the body systems are affected by increased levels of bilirubin. The aim of this study is to investigate the function of platelets and clotting dynamics in patients with obstructive jaundice. Methods:, Liver function tests, serum CRP, PT, PTT and hemogram were measured in 23 patients with obstructive jaundice. Thromboelastography (TEG) was done for the evaluation of coagulation dynamics, while platelet function assay (PFA 100) was used to evaluate platelet functions. Blood samples were obtained at two occasions, before the drainage and 3 weeks after the relief of the obstruction. Results:, Hypercoagulation was detected in 80% of patients. Maximum strength, elasticity, coagulation indices of the clot were correlated with increased concentrations of direct bilirubin. Although maximum strength of coagulum usually represents increased activity of platelet function, membrane closure times with PFA 100 were found to be prolonged in 30% of patients, reduced values were determined in 17% of patients. No demonstrable effect on coagulation parameters and platelet function were detected after drainage procedures regardless of modality. Conclusions:, Even though there is a general assumption about the increased bleeding tendency in obstructive jaundiced patients, we could not demonstrate reduced clotting activity by measuring with either PFA or TEG. On the contrary we observed tendency for hypercoagulation independent of increased prothrombin times. The most probable cause of this effect is the increased activity of fibrin polymers on platelet membrane. [source]

Effects of detraining on muscle strength and mass after high or moderate intensity of resistance training in older adults

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2009
Savvas P. Tokmakidis
Summary This study examined the effects of a 12 weeks detraining period on muscle strength and mass in older adults who had previously participated in a 12 weeks resistance training programme of high [80% of one repetition maximum (1-RM)] or moderate (60% of 1-RM) intensity. Twenty older adults (60,74 years), separated into a high (HI; n = 10; age: 65 ± 5 years) and a moderate (MI; n = 10; age: 66 ± 4 years) intensity resistance training group, were measured in the 1-RM knee extension and flexion strength, and the midthigh cross sectional areas (CSAs) of quadriceps, hamstrings and total thigh before and after a 12 weeks training period as well as after a 12 weeks detraining period. Maximum knee extension and flexion strength and the CSAs of all muscles decreased significantly (P<0·05) with detraining but remained higher (P<0·05) than pretraining levels for both groups. The HI group had a greater decrement (P<0·05) in maximum strength and the CSA of total thigh compared to the MI group but strength levels and the CSA following detraining were higher (P<0·05) for the HI group. The above data suggest that after a short detraining period of 12 weeks, muscle strength and hypertrophy levels of older adults decrease but remain greater than pretraining irrespective of training intensity. Greater declines in muscle strength are observed following HI training but still muscular strength and muscle mass are retained at a higher level than with MI probably due to the higher gains achieved during the training period. [source]