AIMS To.determine the interleuking-2 and interleukin- 2 receptor (IL-2/IL-2R) system in patients with liver cirrhosis and carcinoma and compare their immune functions. The clinical significance is also discussed. METH...AIMS To.determine the interleuking-2 and interleukin- 2 receptor (IL-2/IL-2R) system in patients with liver cirrhosis and carcinoma and compare their immune functions. The clinical significance is also discussed. METHODS Fifty patients with Liver cirrhosis (LC), 50 patients with hepatocellular carcinoma (HCC) and 30 normal controls were studied. The expression of mlL-2R was examined by immunofluorescence. IL-2's activity and serum level of soluble interleukin-2 recep- tor (sIL-2R) were measured by enzyme linked im- munosorbent assay. RESULTS IL-2's activity and the percentage of mIL- 2R expression in carcinoma were significantly lower than those in cirrhosis (P<0.01) and controls (P< 0.01),while the IL-2's activity and the expression of mlL-2R in cirrhosis were also lower than normal controls (P<0.05). The serum level of sIL-2R in carcinoma was significantly higher than that in cirrhosis (P<0.05) and controls (P<0.01),and the level in cirrhosis was higher than in controls (P<0.05). CONCLUSIONS Patients with liver cirhosis and car- cinoma share the decreased immune function of similar nature,but the latter has a more profound degree. Such resemblance in immune disturbances may be the important factor affecting the carcinogenesis of cirrhotic liver.展开更多
AIM To investigate the diagnostic accuracy of Fibro Scan(FS) in detecting esophageal varices(EV) in cirrhotic patients.METHODS Through a systemic literature search of multiple databases, we reviewed 15 studies using e...AIM To investigate the diagnostic accuracy of Fibro Scan(FS) in detecting esophageal varices(EV) in cirrhotic patients.METHODS Through a systemic literature search of multiple databases, we reviewed 15 studies using endoscopy as a reference standard, with the data necessary to calculate pooled sensitivity(SEN) and specificity(SPE), positive and negative LR, diagnostic odds ratio(DOR) and area under receiver operating characteristics(AUROC). The quality of the studies was rated by the Quality Assessment of Diagnostic Accuracy studies-2 tool. Clinical utility of FS for EV was evaluated by a Fagan plot. Heterogeneity was explored using meta-regression and subgroup analysis. All statistical analyses were conducted via Stata12.0, MetaD isc1.4 and RevM an5.RESULTS In 15 studies(n = 2697), FS detected the presence of EV with the summary sensitivities of 84%(95%CI: 81.0%-86.0%), specificities of 62%(95%CI: 58.0%-66.0%), a positive LR of 2.3(95%CI: 1.81-2.94), a negative LR of 0.26(95%CI: 0.19-0.35), a DOR of 9.33(95%CI: 5.84-14.92) and an AUROC of 0.8262. FS diagnosed the presence of large EV with the pooled SEN of 0.78(95%CI: 75.0%-81.0%), SPE of 0.76(95%CI: 73.0%-78.0%), a positive and negative LR of 3.03(95%CI: 2.38-3.86) and 0.30(95%CI: 0.23-0.39) respectively, a summary diagnostic OR of 10.69(95%CI: 6.81-16.78), and an AUROC of 0.8321. A meta-regression and subgroup analysis indicated different etiology could serve as a potential source of heterogeneity in the diagnosis of the presence of EV group. A Deek's funnel plot suggested a low probability for publication bias.CONCLUSION Using FS to measure liver stiffness cannot provide high accuracy for the size of EV due to the various cutoff and different etiologies. These limitations preclude widespread use in clinical practice at this time; therefore, the results should be interpreted cautiously given its SEN and SPE.展开更多
Objective To study the relationship between carotid atherosclerosis and cerebral infarction (CI). Methods Between November 2008 and March 2009,147 CI patients (CI group) and 48 patients with non-cerebrovascular diseas...Objective To study the relationship between carotid atherosclerosis and cerebral infarction (CI). Methods Between November 2008 and March 2009,147 CI patients (CI group) and 48 patients with non-cerebrovascular diseases (control group) were enrolled from inpatients of Neurology Department of our hospital. The diagnostic criterion of thickened carotid intima was set as 1.0 mm≤intima-media thickness (IMT) <1.5 mm and that of carotid plaque was as IMT≥1.5 mm. Carotid atherosclerosis was divided into three levels: normal intima,thickened intima,and plaque formation. The color Doppler ultrasonography data of carotid arteries in all patients were analyzed and the severity of carotid atherosclerosis was compared between the two groups. Results In the CI group,36 (24.5%) patients had normal carotid intima,22 (15.0%) had thickened carotid intima,and 89 (60.5%) had carotid plaque. In the control group,22 (45.8%) patients had normal carotid intima,4 (8.3%) had thickened carotid intima,and 22 (45.8%) had carotid plaque. The severity of carotid atherosclerosis in the CI group was higher than that in the control group (P=0.022). There was significant difference in the constitution of carotid plaque between the two groups (P=0.001); the CI group mainly had the soft plaque (55/89,61.8%),whereas the control group mainly had the hard plaque (17/22,77.3%). The first three common locations of carotid plaque in both groups were carotid bifurcation (CI group: 73.7%; control group: 64.1%),common carotid artery (CI group: 20.4%; control group: 25.6%),and internal carotid artery (CI group: 5.9%; control group: 10.3%). The location of carotid plaque between the two groups was not significantly different (P=0.438). There was no difference in the carotid inner diameter or resistance index between the two groups (P>0.05). Conclusions Carotid atherosclerosis is to some extent able to reveal the atherosclerotic condition of cerebral arteries and act as an important predictor for the risk of CI. The color Doppler ultrasonography of carotid arteries can provide a convenient way for the prevention and treatment of CI.展开更多
The effect of strain hardening and strain softening behavior of flow stress changing with temperature on welding residual stress, plastic strain and welding distortion of ATN0 1-T4 aluminum alloy was studied by finite...The effect of strain hardening and strain softening behavior of flow stress changing with temperature on welding residual stress, plastic strain and welding distortion of ATN0 1-T4 aluminum alloy was studied by finite simulation method. The simulation results show that the weld seam undergoes strain hardening in the temperature range of 180-250 ℃, however, it exhibits strain softening at temperature above 250 ℃ during welding heating and cooling process. As a result, the strain hardening and strain softening effects counteract each other, introducing slightly influence on the welding residual stress, residual plastic strain and distortion. The welding longitudinal residual stress was determined by ultrasonic stress measurement method for the flat plates of A7N01-T4 aluminum alloy. The simulation results are well accordant with test ones.展开更多
Objective: To observe the difference of androgen and inflammatory cytokines level in atherosclerosis and analyse their relations. Method: Both carotid arteries and arteries of lower extremity were subjected to ultra...Objective: To observe the difference of androgen and inflammatory cytokines level in atherosclerosis and analyse their relations. Method: Both carotid arteries and arteries of lower extremity were subjected to ultrasonic examination by Doppier's method. Those with much atheromatous plaque formation were ranged into case group, and those with normal result formed control group. Total, free testosterone and estradiol were assayed by radioimmunoassay. C reactive protein (CRP) was assayed by nepheloturbidity. Tumor necrosis factor-α(TNF-α), lnterleukin-6 (IL-6), lnterleukin-8 (IL-8), lnterleukin-10 (IL-10), Interleukin-18 (IL-18), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were assayed by ELISA. The mean difference between two groups and the correlation between free testosterone and cytokines were analysed. Results: Free testosterone was (6.337±3.371) pg/L in case group and (11.375±4.733)pg/L in control group, P〈0.01. No differences were found in total testosterone and estradiol. CRP was (27.294±10.238)mg/L in case group and (12.843±6.318) mg/L in control group, P〈0.01. IL-6 was (41.700±31.385)pg/L in case group and (25.396±20.772)pg/L in control group, P〈0.05. IL-8 was (89.249±58.357)pg/L in case group and (67.873±31.227)pg/L in control group, P〈0.05. sICAM-1 was (470.491±134.078)pg/L in case group and (368.487±97.183)pg/L in control group, P〈0.01. sVCAM-1 was (537.808±213.172)pg/L in case group and (457.275±157.273)pg/L in control group, P〈0.05. There were no differences in TNF-α, IL-10 and IL-18. Correlation analysis showed that FT (free testosterone) had negative correlation with CRP, IL-6 and sICAM-1. Among them FT had well correlation with CRP, correlation index was -0.678. Conclusion: Free testosterone was in negative correlation with atherosclerosis in old-age male. Free testosterone may have the role of anti-atherosclerosis, and this effect was not achieved by its transformation to estradiol. Low tree testosterone level was followed by increased level of inflammatory cytokines. Low free testosterones coexist with inflammation and they both affect the process of atherosclerosis in old-age male.展开更多
AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% ...AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% NaCl high-salt (HS) or 0.4% NaCl (normal-salt, NS) diet for 3 wk, with or without tempol (T) (1 mmol/L, administered in drinking water). Mean arterial pressure (MAP), glomerular fltration rate (GFR), and urinary sodium excretion (UVNa) were measured. We evaluated angiotensin Ⅱ (Ang Ⅱ), angiotensin 1-7 (Ang 1-7), angiotensin converting enzyme 2 (ACE2), mas receptor (MasR), angiotensin type 1 receptor (AT1R) and angiotensin type 2 receptor (AT2R) in renal tissues by immunohistochemistry.RESULTSThe intake of high sodium produced a slight but signifcant increase in MAP and differentially regulated components of the renal renin-angiotensin system (RAS). This included an increase in Ang Ⅱ and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang Ⅱ and AT1R, as increase in AT2, ACE2, Ang (1-7) and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang (1-7) and MasR.CONCLUSION These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang Ⅱ. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS.展开更多
Non-selective beta-blockers(NSBBs) have been at the forefront in the management of portal hypertension in liver cirrhosis for the last three decades, a trusty component in the armamentarium of the Hepatologist. The ro...Non-selective beta-blockers(NSBBs) have been at the forefront in the management of portal hypertension in liver cirrhosis for the last three decades, a trusty component in the armamentarium of the Hepatologist. The role of beta-blockers has been cemented for years in cardiac disease including angina, hypertension and in heart failure, however NSBBs with their non-selective effects on β1 and β2 receptors have led to them fondly being termed "the hepatologist's aspirin". NSBBs' role in reduction of portal pressure in the setting of primary and secondary prophylaxis for variceal haemorrhage has been well established. NSBBs include propranolol, nadolol and carvedilol- with the latter having been shown to be effective in patients who often fail to demonstrate a haemodynamic response to propranolol. Recent observational studies however have served for the Hepatology community to question the beneficial role of NSBBs in portal hypertension, especially in advanced cases with refractory ascites. The deleterious effect in patients with refractory ascites in a few studies led to a U-turn in clinical practice, with some in the Hepatology community withdrawing their usage in patients with advanced cirrhosis. This also led to the "window hypothesis" suggesting there may be only be a finite time frame when NSBBs have a beneficial effect in portal hypertension. The window hypothesis proposed the window for the benefits of NSBBs is closed in early portal hypertension, opening as portal hypertension progresses with it closing in advanced liver disease. The window was proposed to close in conditions such as refractory ascites or spontaneous bacterial peritonitis when patients may not necessarily mount a compensatory haemodynamic response when on NSBBs. Some centres however have continued the practice of NSBBs in advanced cirrhosis with published data challenging the scepticisms of other groups who stop NSBBs. Thus the debate, like the window hypothesis has opened, with more questions to be answered about NSBB's mechanism of action not only in reducing portal hypertension but also their effects on systemic haemodynamics and on the pro-inflammatory pathways often activated in cirrhosis especially in advanced disease. This article serves to review the role of NSBBs in the management of portal hypertension/cirrhosis and concentrate on current concepts and controversies in this field.展开更多
Aim To construct an analytic solution for the asymptotic field near a tensile cracktip of power-law hardening material under Plane stress condition. Methods Constructing funtion method was used. Results The exact as...Aim To construct an analytic solution for the asymptotic field near a tensile cracktip of power-law hardening material under Plane stress condition. Methods Constructing funtion method was used. Results The exact asymptotic field was found. Conclusion The exact analytic solution for the problem is available.展开更多
Collapsing focal segmental glomerulosclerosis (cFSGS), also known as collapsing glomerulopathy is currently classified under the rubric of FSGS. However, its de-fining morphological features are in stark contrast to...Collapsing focal segmental glomerulosclerosis (cFSGS), also known as collapsing glomerulopathy is currently classified under the rubric of FSGS. However, its de-fining morphological features are in stark contrast to those observed in most other variants of FSGS. During the early stage of the disease, the lesion is character-ized pathologically by an implosive segmental and/or global collapse of the glomerular capillary tufts, marked hypertrophy and hyperplasia of podocytes, and severe tubulointerstitial disease. With advancement of the disease, segmental and/or global glomerulosclerosis is also observed in association with the collapsing le-sions. The etiology of this enigmatic disorder is still elusive, but a growing list of diseases/conditions is being reported in association with this morphological pattern of renal parenchymal injury. The pathogenesis of cFSGS involves discreet epithelial cell injury leadingto cell cycle dysregulation and a proliferative cellularphenotype. From the clinical perspective, cFSGS is no-torious for its propensity to affect black people, a highincidence and severity of nephrotic syndrome, markedresistance to empirical therapy, and rapid progressionto end-stage renal disease. The lesion has also beenreported in transplanted kidneys either as recurrent orde novo disease, frequently leading to graft loss. Mostcases have been reported in western countries, but the lesion is also being increasingly recognized in the tropi-cal regions. The recent increase in reporting of cFSGS partly refects a true increase in the incidence and part-ly a detection bias. There is no specifc treatment for the disorder at present. Newer insights into the patho-genesis may lead to the development of targeted and specifc therapy in near future. There is an urgent need to increase awareness of the lesion among pathologists and nephrologists, especially those from developing countries, to ensure accurate diagnosis and appropriate managment. With the accumulation of more and more data, it is hoped that the prevailing confusion about the nosological identity of the lesion will also be resolved in a more logical way.展开更多
AIM: To evaluate the myoelectric manifestations of peripheral fatigability in patients with primary biliary cirrhosis in comparison to healthy subjects. METHODS: Sixteen women with primary biliary cirrhosis without ...AIM: To evaluate the myoelectric manifestations of peripheral fatigability in patients with primary biliary cirrhosis in comparison to healthy subjects. METHODS: Sixteen women with primary biliary cirrhosis without comorbidity and 13 healthy women matched for age and body mass index (BMI) completed the selfreported questionnaire fatigue impact scale. All subjects underwent surface electromyography assessment of peripheral fatigability. Anterior tibial muscle isometric voluntary contraction was executed for 20 s at 80% of maximal voluntary isometric contraction. During the exercise electromyographic signal series were recorded and root mean square (expression of central drive) as well as mean and median of electromyographic signal frequency spectrum (estimates of muscle fatigability) were com- puted. Each subject executed the trial two times. EMG parameters were normalized, then linear regression was applied and slopes were calculated. RESULTS: Seven patients were fatigued (median fatigue impact scale score: 38, range: 26-66) and 9 were not fatigued (median fatigue impact scale score: 7, range: 0-17). The maximal voluntary isometric contraction was similar in patients (82, 54-115 N) and controls (87, 74-101 N), and in patients with high (81, 54-115 N) and low fatigue impact scale scores (86, 65-106 N). Root mean square as well as mean and median of frequency spectrum slopes were compared with the Mann-Whitney U test, and no significant difference was found between fatigued and non-fatigued patients and controls. CONCLUSION: No instrumental evidence of peripheral fatigability can be found in women with primary biliary cirrhosis but no comorbidity, suggesting that fatigue in such patients may be of central origin.展开更多
AIM:To identify possible predictive factors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.METHODS: From January 2000 to July 2007, 128 patients w...AIM:To identify possible predictive factors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.METHODS: From January 2000 to July 2007, 128 patients with acute non-variceal gastrointestinal bleeding had negative f indings after initial angiography. Clinical and laboratory parameters were analyzed retrospectively.RESULTS: Among 128 patients, 62 had no recurrent gastrointestinal bleeding and 66 had recurrent gastrointestinal bleeding within 30 d. As determined by the use of multivariate analysis, an underlying malignancy, liver cirrhosis and hematemesis were significant factors related to recurrent gastrointestinal bleeding.CONCLUSION: Clinical factors including underlying malignancy, liver cirrhosis, and hematemesis are important predictors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.展开更多
This paper investigates the rolling contact fatigue of kiln wheels with respect to the axis line deflection, which is linear with the applied supporting loads on wheels. Fatigue crack initiation criteria for elastic s...This paper investigates the rolling contact fatigue of kiln wheels with respect to the axis line deflection, which is linear with the applied supporting loads on wheels. Fatigue crack initiation criteria for elastic shakedown, plastic shakedown and ratcheting material responses are applied to assess wheels responses with two sets of axial line deflection. The finite element simulations are performed by using the bilinear material mode for nonlinear and kinematic hardening in ANSYS 11.0. By comparing the results from different critera, it is showed that the low-cycle fatigue is the predominated failure. Results from different axial line deflections indicate that the optimum adjustment can greatly enhance the whole life of the supporting structure.展开更多
The laser-induced fluorescence excitation spectrum of CoC was recorded in the spectral region from 13500 cm^-1 to 22000 cm^-1, in which the CoC molecules were produced by the reaction of sputtered cobalt atoms with me...The laser-induced fluorescence excitation spectrum of CoC was recorded in the spectral region from 13500 cm^-1 to 22000 cm^-1, in which the CoC molecules were produced by the reaction of sputtered cobalt atoms with methanol under supersonic jet cooled conditions. Much of the visible spectrum was assigned to transitions between the X2∑^+ ground state and F2∑^+ state. The 11 bands assigned as (v'=3-13, 0) transitions of the F^2∑^+-X^2∑^+ band system were observed and rotationally analyzed. Equilibrium constants for the F^2∑^+ state were Te=13628 cm^-1, We=669 cm^-1, ωeХe=4.3 cm^-1, Be=0.546 cm^-1, and Re=1.758A. Some new bands were observed.展开更多
基金Supported by Fujian Proviacial Health Bureau 91A047.
文摘AIMS To.determine the interleuking-2 and interleukin- 2 receptor (IL-2/IL-2R) system in patients with liver cirrhosis and carcinoma and compare their immune functions. The clinical significance is also discussed. METHODS Fifty patients with Liver cirrhosis (LC), 50 patients with hepatocellular carcinoma (HCC) and 30 normal controls were studied. The expression of mlL-2R was examined by immunofluorescence. IL-2's activity and serum level of soluble interleukin-2 recep- tor (sIL-2R) were measured by enzyme linked im- munosorbent assay. RESULTS IL-2's activity and the percentage of mIL- 2R expression in carcinoma were significantly lower than those in cirrhosis (P<0.01) and controls (P< 0.01),while the IL-2's activity and the expression of mlL-2R in cirrhosis were also lower than normal controls (P<0.05). The serum level of sIL-2R in carcinoma was significantly higher than that in cirrhosis (P<0.05) and controls (P<0.01),and the level in cirrhosis was higher than in controls (P<0.05). CONCLUSIONS Patients with liver cirhosis and car- cinoma share the decreased immune function of similar nature,but the latter has a more profound degree. Such resemblance in immune disturbances may be the important factor affecting the carcinogenesis of cirrhotic liver.
文摘AIM To investigate the diagnostic accuracy of Fibro Scan(FS) in detecting esophageal varices(EV) in cirrhotic patients.METHODS Through a systemic literature search of multiple databases, we reviewed 15 studies using endoscopy as a reference standard, with the data necessary to calculate pooled sensitivity(SEN) and specificity(SPE), positive and negative LR, diagnostic odds ratio(DOR) and area under receiver operating characteristics(AUROC). The quality of the studies was rated by the Quality Assessment of Diagnostic Accuracy studies-2 tool. Clinical utility of FS for EV was evaluated by a Fagan plot. Heterogeneity was explored using meta-regression and subgroup analysis. All statistical analyses were conducted via Stata12.0, MetaD isc1.4 and RevM an5.RESULTS In 15 studies(n = 2697), FS detected the presence of EV with the summary sensitivities of 84%(95%CI: 81.0%-86.0%), specificities of 62%(95%CI: 58.0%-66.0%), a positive LR of 2.3(95%CI: 1.81-2.94), a negative LR of 0.26(95%CI: 0.19-0.35), a DOR of 9.33(95%CI: 5.84-14.92) and an AUROC of 0.8262. FS diagnosed the presence of large EV with the pooled SEN of 0.78(95%CI: 75.0%-81.0%), SPE of 0.76(95%CI: 73.0%-78.0%), a positive and negative LR of 3.03(95%CI: 2.38-3.86) and 0.30(95%CI: 0.23-0.39) respectively, a summary diagnostic OR of 10.69(95%CI: 6.81-16.78), and an AUROC of 0.8321. A meta-regression and subgroup analysis indicated different etiology could serve as a potential source of heterogeneity in the diagnosis of the presence of EV group. A Deek's funnel plot suggested a low probability for publication bias.CONCLUSION Using FS to measure liver stiffness cannot provide high accuracy for the size of EV due to the various cutoff and different etiologies. These limitations preclude widespread use in clinical practice at this time; therefore, the results should be interpreted cautiously given its SEN and SPE.
文摘Objective To study the relationship between carotid atherosclerosis and cerebral infarction (CI). Methods Between November 2008 and March 2009,147 CI patients (CI group) and 48 patients with non-cerebrovascular diseases (control group) were enrolled from inpatients of Neurology Department of our hospital. The diagnostic criterion of thickened carotid intima was set as 1.0 mm≤intima-media thickness (IMT) <1.5 mm and that of carotid plaque was as IMT≥1.5 mm. Carotid atherosclerosis was divided into three levels: normal intima,thickened intima,and plaque formation. The color Doppler ultrasonography data of carotid arteries in all patients were analyzed and the severity of carotid atherosclerosis was compared between the two groups. Results In the CI group,36 (24.5%) patients had normal carotid intima,22 (15.0%) had thickened carotid intima,and 89 (60.5%) had carotid plaque. In the control group,22 (45.8%) patients had normal carotid intima,4 (8.3%) had thickened carotid intima,and 22 (45.8%) had carotid plaque. The severity of carotid atherosclerosis in the CI group was higher than that in the control group (P=0.022). There was significant difference in the constitution of carotid plaque between the two groups (P=0.001); the CI group mainly had the soft plaque (55/89,61.8%),whereas the control group mainly had the hard plaque (17/22,77.3%). The first three common locations of carotid plaque in both groups were carotid bifurcation (CI group: 73.7%; control group: 64.1%),common carotid artery (CI group: 20.4%; control group: 25.6%),and internal carotid artery (CI group: 5.9%; control group: 10.3%). The location of carotid plaque between the two groups was not significantly different (P=0.438). There was no difference in the carotid inner diameter or resistance index between the two groups (P>0.05). Conclusions Carotid atherosclerosis is to some extent able to reveal the atherosclerotic condition of cerebral arteries and act as an important predictor for the risk of CI. The color Doppler ultrasonography of carotid arteries can provide a convenient way for the prevention and treatment of CI.
基金Project(2007DFR70070) supported by China-Russia Government-to-Government Scientific and Technical Cooperation Foundation
文摘The effect of strain hardening and strain softening behavior of flow stress changing with temperature on welding residual stress, plastic strain and welding distortion of ATN0 1-T4 aluminum alloy was studied by finite simulation method. The simulation results show that the weld seam undergoes strain hardening in the temperature range of 180-250 ℃, however, it exhibits strain softening at temperature above 250 ℃ during welding heating and cooling process. As a result, the strain hardening and strain softening effects counteract each other, introducing slightly influence on the welding residual stress, residual plastic strain and distortion. The welding longitudinal residual stress was determined by ultrasonic stress measurement method for the flat plates of A7N01-T4 aluminum alloy. The simulation results are well accordant with test ones.
基金Project (No. 2003B045) supported by the Health Bureau of ZhejiangProvince, China
文摘Objective: To observe the difference of androgen and inflammatory cytokines level in atherosclerosis and analyse their relations. Method: Both carotid arteries and arteries of lower extremity were subjected to ultrasonic examination by Doppier's method. Those with much atheromatous plaque formation were ranged into case group, and those with normal result formed control group. Total, free testosterone and estradiol were assayed by radioimmunoassay. C reactive protein (CRP) was assayed by nepheloturbidity. Tumor necrosis factor-α(TNF-α), lnterleukin-6 (IL-6), lnterleukin-8 (IL-8), lnterleukin-10 (IL-10), Interleukin-18 (IL-18), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were assayed by ELISA. The mean difference between two groups and the correlation between free testosterone and cytokines were analysed. Results: Free testosterone was (6.337±3.371) pg/L in case group and (11.375±4.733)pg/L in control group, P〈0.01. No differences were found in total testosterone and estradiol. CRP was (27.294±10.238)mg/L in case group and (12.843±6.318) mg/L in control group, P〈0.01. IL-6 was (41.700±31.385)pg/L in case group and (25.396±20.772)pg/L in control group, P〈0.05. IL-8 was (89.249±58.357)pg/L in case group and (67.873±31.227)pg/L in control group, P〈0.05. sICAM-1 was (470.491±134.078)pg/L in case group and (368.487±97.183)pg/L in control group, P〈0.01. sVCAM-1 was (537.808±213.172)pg/L in case group and (457.275±157.273)pg/L in control group, P〈0.05. There were no differences in TNF-α, IL-10 and IL-18. Correlation analysis showed that FT (free testosterone) had negative correlation with CRP, IL-6 and sICAM-1. Among them FT had well correlation with CRP, correlation index was -0.678. Conclusion: Free testosterone was in negative correlation with atherosclerosis in old-age male. Free testosterone may have the role of anti-atherosclerosis, and this effect was not achieved by its transformation to estradiol. Low tree testosterone level was followed by increased level of inflammatory cytokines. Low free testosterones coexist with inflammation and they both affect the process of atherosclerosis in old-age male.
基金Supported by A grant from the Universidad de Buenos Aires(UBACYT 20020130200105BA)
文摘AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% NaCl high-salt (HS) or 0.4% NaCl (normal-salt, NS) diet for 3 wk, with or without tempol (T) (1 mmol/L, administered in drinking water). Mean arterial pressure (MAP), glomerular fltration rate (GFR), and urinary sodium excretion (UVNa) were measured. We evaluated angiotensin Ⅱ (Ang Ⅱ), angiotensin 1-7 (Ang 1-7), angiotensin converting enzyme 2 (ACE2), mas receptor (MasR), angiotensin type 1 receptor (AT1R) and angiotensin type 2 receptor (AT2R) in renal tissues by immunohistochemistry.RESULTSThe intake of high sodium produced a slight but signifcant increase in MAP and differentially regulated components of the renal renin-angiotensin system (RAS). This included an increase in Ang Ⅱ and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang Ⅱ and AT1R, as increase in AT2, ACE2, Ang (1-7) and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang (1-7) and MasR.CONCLUSION These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang Ⅱ. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS.
文摘Non-selective beta-blockers(NSBBs) have been at the forefront in the management of portal hypertension in liver cirrhosis for the last three decades, a trusty component in the armamentarium of the Hepatologist. The role of beta-blockers has been cemented for years in cardiac disease including angina, hypertension and in heart failure, however NSBBs with their non-selective effects on β1 and β2 receptors have led to them fondly being termed "the hepatologist's aspirin". NSBBs' role in reduction of portal pressure in the setting of primary and secondary prophylaxis for variceal haemorrhage has been well established. NSBBs include propranolol, nadolol and carvedilol- with the latter having been shown to be effective in patients who often fail to demonstrate a haemodynamic response to propranolol. Recent observational studies however have served for the Hepatology community to question the beneficial role of NSBBs in portal hypertension, especially in advanced cases with refractory ascites. The deleterious effect in patients with refractory ascites in a few studies led to a U-turn in clinical practice, with some in the Hepatology community withdrawing their usage in patients with advanced cirrhosis. This also led to the "window hypothesis" suggesting there may be only be a finite time frame when NSBBs have a beneficial effect in portal hypertension. The window hypothesis proposed the window for the benefits of NSBBs is closed in early portal hypertension, opening as portal hypertension progresses with it closing in advanced liver disease. The window was proposed to close in conditions such as refractory ascites or spontaneous bacterial peritonitis when patients may not necessarily mount a compensatory haemodynamic response when on NSBBs. Some centres however have continued the practice of NSBBs in advanced cirrhosis with published data challenging the scepticisms of other groups who stop NSBBs. Thus the debate, like the window hypothesis has opened, with more questions to be answered about NSBB's mechanism of action not only in reducing portal hypertension but also their effects on systemic haemodynamics and on the pro-inflammatory pathways often activated in cirrhosis especially in advanced disease. This article serves to review the role of NSBBs in the management of portal hypertension/cirrhosis and concentrate on current concepts and controversies in this field.
文摘Aim To construct an analytic solution for the asymptotic field near a tensile cracktip of power-law hardening material under Plane stress condition. Methods Constructing funtion method was used. Results The exact asymptotic field was found. Conclusion The exact analytic solution for the problem is available.
文摘Collapsing focal segmental glomerulosclerosis (cFSGS), also known as collapsing glomerulopathy is currently classified under the rubric of FSGS. However, its de-fining morphological features are in stark contrast to those observed in most other variants of FSGS. During the early stage of the disease, the lesion is character-ized pathologically by an implosive segmental and/or global collapse of the glomerular capillary tufts, marked hypertrophy and hyperplasia of podocytes, and severe tubulointerstitial disease. With advancement of the disease, segmental and/or global glomerulosclerosis is also observed in association with the collapsing le-sions. The etiology of this enigmatic disorder is still elusive, but a growing list of diseases/conditions is being reported in association with this morphological pattern of renal parenchymal injury. The pathogenesis of cFSGS involves discreet epithelial cell injury leadingto cell cycle dysregulation and a proliferative cellularphenotype. From the clinical perspective, cFSGS is no-torious for its propensity to affect black people, a highincidence and severity of nephrotic syndrome, markedresistance to empirical therapy, and rapid progressionto end-stage renal disease. The lesion has also beenreported in transplanted kidneys either as recurrent orde novo disease, frequently leading to graft loss. Mostcases have been reported in western countries, but the lesion is also being increasingly recognized in the tropi-cal regions. The recent increase in reporting of cFSGS partly refects a true increase in the incidence and part-ly a detection bias. There is no specifc treatment for the disorder at present. Newer insights into the patho-genesis may lead to the development of targeted and specifc therapy in near future. There is an urgent need to increase awareness of the lesion among pathologists and nephrologists, especially those from developing countries, to ensure accurate diagnosis and appropriate managment. With the accumulation of more and more data, it is hoped that the prevailing confusion about the nosological identity of the lesion will also be resolved in a more logical way.
文摘AIM: To evaluate the myoelectric manifestations of peripheral fatigability in patients with primary biliary cirrhosis in comparison to healthy subjects. METHODS: Sixteen women with primary biliary cirrhosis without comorbidity and 13 healthy women matched for age and body mass index (BMI) completed the selfreported questionnaire fatigue impact scale. All subjects underwent surface electromyography assessment of peripheral fatigability. Anterior tibial muscle isometric voluntary contraction was executed for 20 s at 80% of maximal voluntary isometric contraction. During the exercise electromyographic signal series were recorded and root mean square (expression of central drive) as well as mean and median of electromyographic signal frequency spectrum (estimates of muscle fatigability) were com- puted. Each subject executed the trial two times. EMG parameters were normalized, then linear regression was applied and slopes were calculated. RESULTS: Seven patients were fatigued (median fatigue impact scale score: 38, range: 26-66) and 9 were not fatigued (median fatigue impact scale score: 7, range: 0-17). The maximal voluntary isometric contraction was similar in patients (82, 54-115 N) and controls (87, 74-101 N), and in patients with high (81, 54-115 N) and low fatigue impact scale scores (86, 65-106 N). Root mean square as well as mean and median of frequency spectrum slopes were compared with the Mann-Whitney U test, and no significant difference was found between fatigued and non-fatigued patients and controls. CONCLUSION: No instrumental evidence of peripheral fatigability can be found in women with primary biliary cirrhosis but no comorbidity, suggesting that fatigue in such patients may be of central origin.
文摘AIM:To identify possible predictive factors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.METHODS: From January 2000 to July 2007, 128 patients with acute non-variceal gastrointestinal bleeding had negative f indings after initial angiography. Clinical and laboratory parameters were analyzed retrospectively.RESULTS: Among 128 patients, 62 had no recurrent gastrointestinal bleeding and 66 had recurrent gastrointestinal bleeding within 30 d. As determined by the use of multivariate analysis, an underlying malignancy, liver cirrhosis and hematemesis were significant factors related to recurrent gastrointestinal bleeding.CONCLUSION: Clinical factors including underlying malignancy, liver cirrhosis, and hematemesis are important predictors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.
基金supported by the National Natural Science Foundation of China(No.51075140)Scientific Research Fund of Hunan Provincial Education Department(No.09C407)
文摘This paper investigates the rolling contact fatigue of kiln wheels with respect to the axis line deflection, which is linear with the applied supporting loads on wheels. Fatigue crack initiation criteria for elastic shakedown, plastic shakedown and ratcheting material responses are applied to assess wheels responses with two sets of axial line deflection. The finite element simulations are performed by using the bilinear material mode for nonlinear and kinematic hardening in ANSYS 11.0. By comparing the results from different critera, it is showed that the low-cycle fatigue is the predominated failure. Results from different axial line deflections indicate that the optimum adjustment can greatly enhance the whole life of the supporting structure.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20433080 and No.20673107), the National Key Basic Research Special Foundation of China (No.2007CB815203), and the Chinese Academy of Science (KJCX2-YW-N24).
文摘The laser-induced fluorescence excitation spectrum of CoC was recorded in the spectral region from 13500 cm^-1 to 22000 cm^-1, in which the CoC molecules were produced by the reaction of sputtered cobalt atoms with methanol under supersonic jet cooled conditions. Much of the visible spectrum was assigned to transitions between the X2∑^+ ground state and F2∑^+ state. The 11 bands assigned as (v'=3-13, 0) transitions of the F^2∑^+-X^2∑^+ band system were observed and rotationally analyzed. Equilibrium constants for the F^2∑^+ state were Te=13628 cm^-1, We=669 cm^-1, ωeХe=4.3 cm^-1, Be=0.546 cm^-1, and Re=1.758A. Some new bands were observed.