AIM： To study the value of biochemical and ultrasonographic parameters in prediction of presence and size of esophageal varices.METHODS： The study includes selected cirrhotic patients who underwent a complete bioche...AIM： To study the value of biochemical and ultrasonographic parameters in prediction of presence and size of esophageal varices.METHODS： The study includes selected cirrhotic patients who underwent a complete biochemical workup, upper digestive endoscopic and ultrasonographic examinations. Albumin/right liver lobe diameter and platelet count/spleen diameter ratios were calculated. The correlation between calculated ratio and the presence and degree of esophageal varices was evaluated.RESULTS： Ninety-four subjects （62 males, 32 females）, with a mean age of 52.32 ± 13.60 years, were studied. Child-Pugh class A accounted for 42.6%, class 13 37.2%, whereas class C 20.2%. Esophageal varices （OE） were not demonstrated by upper digestive endoscopy in 24.5%, while OE grade Iwas found in 22.3% patients, grade Ⅱ in 33.0%, grade m in 16.0%, and grade iV in 4.3%. The mean value of right liver lobe diameter/ albumin ratio was 5.51± 1.82 （range from 2.76 to 11.44）, while the mean platelet count/spleen diameter ratio was 1017.75 ± 729.36 （range from 117.39 to 3362.50）, respectively. Statistically significant correlation was proved by Spearman＇s test between OE grade and calculated ratios. The P values were 0.481 and -0.686, respectively.CONCLUSION： The right liver lobe diameter/albumin and platelet count/spleen diameter ratios are noninvasive parameters providing accurate information pertinent to determination of presence of esophageal varices, and their grading in patients with liver cirrhosis.展开更多
The multi-dimensional time-domain computational fluid dynamics(CFD) approach is extended to calculate the acoustic attenuation performance of water-filled piping silencers. Transmission loss predictions from the time-...The multi-dimensional time-domain computational fluid dynamics(CFD) approach is extended to calculate the acoustic attenuation performance of water-filled piping silencers. Transmission loss predictions from the time-domain CFD approach and the frequency-domain finite element method(FEM) agree well with each other for the dual expansion chamber silencer, straight-through and cross-flow perforated tube silencers without flow. Then, the time-domain CFD approach is used to investigate the effect of flow on the acoustic attenuation characteristics of perforated tube silencers. The numerical predictions demonstrate that the mean flow increases the transmission loss, especially at higher frequencies, and shifts the transmission loss curve to lower frequencies.展开更多
AIM： To evaluate portal hypertension parameters in liver cirrhosis patients with and without esophageal varices （EV）. METHODS： A cohort of patients with biopsy confirmed liver cirrhosis was investigated endoscopic...AIM： To evaluate portal hypertension parameters in liver cirrhosis patients with and without esophageal varices （EV）. METHODS： A cohort of patients with biopsy confirmed liver cirrhosis was investigated endoscopically and with color Doppler ultrasonography as a possible noninvasive predictive tool. The relationship between portal hemodynamics and the presence and size of EV was evaluated using uni- and multivariate approaches. RESULTS： Eighty five consecutive cirrhotic patients （43 men and 42 women） were enrolled. Mean age （± SD） was 47.5 （± 15.9）. Portal vein diameter （13.88 ± 2.42 vs 12.00 ± 1.69, P 〈 0.0005） and liver vascular index （8.31 ± 2.72 vs 17.8 ± 6.28, P 〈 0.0005） were found to be significantly higher in patients with EV irrespective of size and in patients with large varices （14.54 ± 1.48 vs 13.24 ± 2.55, P 〈 0.05 and 6.45 ± 2.78 v$10.96 ± 5.05, P 〈 0.0005, respectively）, while portal vein flow velocity （13.25 ± 3.66 vs 20.25 ± 5.05, P 〈 0.0005）, congestion index （CI） （0.11 ± 0.03 vs 0.06 ± 0.03, P 〈 0.0005）, portal hypertensive index （2.62 ± 0.79 vs 1.33 ± 0.53, P 〈 0.0005）, and hepatic （0.73 ± 0.07 vs 0.66 ± 0.07, P 〈 0.001） and splenic artery resistance index （R/） （0.73 ± 0.06 vs 0.62 ± 0.08, P 〈 0.0005） were significantly lower. A logistic regression model confirmed spleen size （P = 0.002, AUC 0.72） and portal hypertensive index （P = 0.040, AUC 0.79） as independent predictors for the occurrence of large esophageal varices （LEV）. CONCLUSION： Our data suggest two independent situations for beginning endoscopic evaluation of compensated cirrhotic patients： Portal hypertensive index 〉 2.08 and spleen size 〉 15.05 cm. These factors may help identifying patients with a low probability of LEV who may not need upper gastrointestinal endoscopy.展开更多
AIM： To determine factors predictive for esophagea varices in severe alcoholic disease （SAD）. METHODS： Abdominal ultrasonography （US） was performed on 444 patients suffering from alcoholism. Forty-four patients ...AIM： To determine factors predictive for esophagea varices in severe alcoholic disease （SAD）. METHODS： Abdominal ultrasonography （US） was performed on 444 patients suffering from alcoholism. Forty-four patients found to have splenomegaly and/ or withering of the right liver lobe were defined as those with SAD. SAD patients were examined by upper gastrointestinal （UGI） endoscopy for the presence of esophageal varices. The existence of esophageal varices was then related to clinical variables. RESULTS： Twenty-five patients （56.8%） had esophageal varices. A univariate analysis revealed a significant difference in age and type Ⅳ collagen levels between patients with and without esophageal varices. A logistic regression analysis identified type Ⅳ collagen as the only independent variable predictive for esophageal varices （P = 0.017）. The area under the curve （AUC） for type Ⅳ collagen as determined by the receiver operating characteristic （ROC） for predicting esophageal varices was 0.78. CONCLUSION： This study suggests that the level of type Ⅳ collagen has a high diagnostic accuracy for the detection of esophageal varices in SAD.展开更多
For understanding acoustic emission （AE） activity and accumulation of micro-damage inside rock under pure tensile state, the AE signals has been monitored on the test of directly tension on two kinds of marble speci...For understanding acoustic emission （AE） activity and accumulation of micro-damage inside rock under pure tensile state, the AE signals has been monitored on the test of directly tension on two kinds of marble specimens. A tensile constitutive model was proposed with the damage factor calculated by AE energy rate. The tensile strength of marble was discrete obviously and was sensitive to the inside microdefects and grain composition. With increasing of loading, the tensile stress-strain curve obviously showed nonlinear with the tensile tangent modulus decreasing. In repeated loading cycle, the tensile elastic modulus was less than that in the previous loading cycle because of the generation of micro damage during the prior loading. It means the linear weakening occurring in the specimens. The AE activity was corresponding with occurrence of nonlinear deformation. In the initial loading stage which only elastic deformation happened on the specimens, there were few AE events occurred; while when the nonlinear deformation happened with increasing of loading, lots of AE events were generated. The quantity and energy of AE events were proportionally related to the variation of tensile tangent modulus. The Kaiser effect of AE activity could be clearly observed in tensile cycle loading. Based on the theory of damage mechanics, the damage factor was defined by AE energy rate and the tensile damage constitutive model was proposed which only needed two property constants. The theoretical stress-strain curve was well fitted with the curve plotted with tested datum and the two property constants were easily gotten by the laboratory testing.展开更多
AIM： To study the portal hemodynamics and their relationship with the size of esophageal varices seen at endoscopy and to evaluate whether these Doppler ultrasound parameters might predict variceal bleeding in patien...AIM： To study the portal hemodynamics and their relationship with the size of esophageal varices seen at endoscopy and to evaluate whether these Doppler ultrasound parameters might predict variceal bleeding in patients with liver cirrhosis and portal hypertension. METHODS： One hundred and twenty cirrhotic patients with esophageal varices but without any previous bleeding were enrolled in the prospective study. During a 2-year observation period, 52 patients who had at least one episode of acute esophageal variceal hemorrhage constituted the bleeding group, and the remaining 68 patients without any previous hemorrhage constituted the non-bleeding group. All patients underwent endoscopy before or after color Doppler-ultrasonic examination, and images were interpreted independently by two endoscopists. The control group consisted of 30 healthy subjects, matched to the patient group in age and gender. Measurements of diameter, flow direction and flow velocity in the left gastric vein （LGV） and the portal vein （PV） were done in all patients and controls using color Doppler unit. After baseline measurements, 30 min after oral administration of 75 g glucose in 225 mL, changes of the diameter, flow velocity and direction in the PV and LGV were examined in 60 patients with esophageal varices and 15 healthy controls. RESULTS： The PV and LGV were detected successfully in 115 （96%） and 105 （88%） of 120 cirrhotic patients, respectively, and in 27 （90%） and 21 （70%） of 30 healthy controls, respectively. Among the 120 cirrhotic patients, 37 had F1, 59 had F2, and 24 had F3 grade varices. Compared with the healthy controls, cirrhotic group had a significantly lower velocity in the PV, a significantly greater diameter of the PV and LGV, and a higher velocity in the LGV. In the cirrhotic group, no difference in portal flow velocity and diameter were observed between patients with or without esophageal variceal bleeding （EVB）. However, the diameter and blood flow velocity of the LGV were significantly higher for EVB （＋） group compared with EVB （-） group （P〈0.01）. Diameter of the LGV increased with enlarged size of varices. There were differences between F1 and F2, F1 and F3 varices, but no differences between F2 and F3 varices （P = 0.125）. However, variceal bleeding was more frequent in patients with a diameter of LGV 〉6 mm. The flow velocity in the LGV of healthy controls was 8.70＋1.91 cm/s （n = 21）. In patients with liver cirrhosis, it was 10.3＋2.1 cm/s （n = 12） when the flow was hepatopetal and 13.5＋2.3 cm/s （n = 87） when it was hepatofugal. As the size of varices enlarged, hepatofugal flow velocity increased （P〈0.01） and was significantly different between patients with F1 and F2 varices and between patients with F2 and F3 varices. Variceal bleeding was more frequent in patients with a hepatofugal flow velocity 〉15 cm/s （32 of 52 patients, 61.5%）. Within the bleeding group, the mean LGV blood flow velocity was 16.6＋2.62 cm/s. No correlation was observed between the portal blood flow velocity and EVB. In all healthy controls, the flow direction in the LGV was hepatopetal, toward the PV. In patients with F1 varices, flow direction was hepatopetal in 10 patients, to-and-fro state in 3 patients, and hepatofugal in the remaining 18. The flow was hepatofugal in 91% patients with F2 and all F3 varices. Changes in diameter of the PV and LGV were not significant before and after ingestion of glucose （PV： 1.41＋1.5 cm before and 1.46＋1.6 cm after; LGV： 0.57＋1.7 cm before and 0.60＋1.5 cm after）. Flow direction in the LGV was hepatopetal and to-and-fro in 16 patients and hepatofugal in 44 patients before ingestion of glucose. Flow direction changed to hepatofugal in 9 of 16 patients with hepatopetal and to-and-fro blood flow after ingestion of glucose. In 44 patients with hepatofugal blood flow in the LGV, a significant increase in hepatofugal flow velocity was observed in 38 of 44 patients （86%） with esophageal varices. There was a relationship between the percentage changes in flow velocity and the size of varices. Patients who responded excessively to food ingestion might have a high risk for bleeding. The changes of blood flow velocity in the LGV were greater than those in the PV （LGV： 28.3＋26.1%, PV： 7.2＋13.2%, P〈0.01）, whereas no significant changes in the LGV occurred before and after ingestion of glucose in the control subjects. CONCLUSION： Hemodynamics of the PV is unrelated to the degree of endoscopic abnormalities in patients with liver cirrhosis. The most important combinations are endoscopic findings followed by the LGV hemodynamics. Duplex-Doppler ultrasonography has no value in the identification of patients with cirrhosis at risk of variceal bleeding. Hemodynamics of the LGV appears to be superior to those of the PV in predicting bleeding.展开更多
文摘AIM： To study the value of biochemical and ultrasonographic parameters in prediction of presence and size of esophageal varices.METHODS： The study includes selected cirrhotic patients who underwent a complete biochemical workup, upper digestive endoscopic and ultrasonographic examinations. Albumin/right liver lobe diameter and platelet count/spleen diameter ratios were calculated. The correlation between calculated ratio and the presence and degree of esophageal varices was evaluated.RESULTS： Ninety-four subjects （62 males, 32 females）, with a mean age of 52.32 ± 13.60 years, were studied. Child-Pugh class A accounted for 42.6%, class 13 37.2%, whereas class C 20.2%. Esophageal varices （OE） were not demonstrated by upper digestive endoscopy in 24.5%, while OE grade Iwas found in 22.3% patients, grade Ⅱ in 33.0%, grade m in 16.0%, and grade iV in 4.3%. The mean value of right liver lobe diameter/ albumin ratio was 5.51± 1.82 （range from 2.76 to 11.44）, while the mean platelet count/spleen diameter ratio was 1017.75 ± 729.36 （range from 117.39 to 3362.50）, respectively. Statistically significant correlation was proved by Spearman＇s test between OE grade and calculated ratios. The P values were 0.481 and -0.686, respectively.CONCLUSION： The right liver lobe diameter/albumin and platelet count/spleen diameter ratios are noninvasive parameters providing accurate information pertinent to determination of presence of esophageal varices, and their grading in patients with liver cirrhosis.
基金Project(11174065)supported by the National Natural Science Foundation of China
文摘The multi-dimensional time-domain computational fluid dynamics(CFD) approach is extended to calculate the acoustic attenuation performance of water-filled piping silencers. Transmission loss predictions from the time-domain CFD approach and the frequency-domain finite element method(FEM) agree well with each other for the dual expansion chamber silencer, straight-through and cross-flow perforated tube silencers without flow. Then, the time-domain CFD approach is used to investigate the effect of flow on the acoustic attenuation characteristics of perforated tube silencers. The numerical predictions demonstrate that the mean flow increases the transmission loss, especially at higher frequencies, and shifts the transmission loss curve to lower frequencies.
基金Supported by Liver and Gastrointestinal Diseases Research Center, Tabriz University of medical sciences
文摘AIM： To evaluate portal hypertension parameters in liver cirrhosis patients with and without esophageal varices （EV）. METHODS： A cohort of patients with biopsy confirmed liver cirrhosis was investigated endoscopically and with color Doppler ultrasonography as a possible noninvasive predictive tool. The relationship between portal hemodynamics and the presence and size of EV was evaluated using uni- and multivariate approaches. RESULTS： Eighty five consecutive cirrhotic patients （43 men and 42 women） were enrolled. Mean age （± SD） was 47.5 （± 15.9）. Portal vein diameter （13.88 ± 2.42 vs 12.00 ± 1.69, P 〈 0.0005） and liver vascular index （8.31 ± 2.72 vs 17.8 ± 6.28, P 〈 0.0005） were found to be significantly higher in patients with EV irrespective of size and in patients with large varices （14.54 ± 1.48 vs 13.24 ± 2.55, P 〈 0.05 and 6.45 ± 2.78 v$10.96 ± 5.05, P 〈 0.0005, respectively）, while portal vein flow velocity （13.25 ± 3.66 vs 20.25 ± 5.05, P 〈 0.0005）, congestion index （CI） （0.11 ± 0.03 vs 0.06 ± 0.03, P 〈 0.0005）, portal hypertensive index （2.62 ± 0.79 vs 1.33 ± 0.53, P 〈 0.0005）, and hepatic （0.73 ± 0.07 vs 0.66 ± 0.07, P 〈 0.001） and splenic artery resistance index （R/） （0.73 ± 0.06 vs 0.62 ± 0.08, P 〈 0.0005） were significantly lower. A logistic regression model confirmed spleen size （P = 0.002, AUC 0.72） and portal hypertensive index （P = 0.040, AUC 0.79） as independent predictors for the occurrence of large esophageal varices （LEV）. CONCLUSION： Our data suggest two independent situations for beginning endoscopic evaluation of compensated cirrhotic patients： Portal hypertensive index 〉 2.08 and spleen size 〉 15.05 cm. These factors may help identifying patients with a low probability of LEV who may not need upper gastrointestinal endoscopy.
文摘AIM： To determine factors predictive for esophagea varices in severe alcoholic disease （SAD）. METHODS： Abdominal ultrasonography （US） was performed on 444 patients suffering from alcoholism. Forty-four patients found to have splenomegaly and/ or withering of the right liver lobe were defined as those with SAD. SAD patients were examined by upper gastrointestinal （UGI） endoscopy for the presence of esophageal varices. The existence of esophageal varices was then related to clinical variables. RESULTS： Twenty-five patients （56.8%） had esophageal varices. A univariate analysis revealed a significant difference in age and type Ⅳ collagen levels between patients with and without esophageal varices. A logistic regression analysis identified type Ⅳ collagen as the only independent variable predictive for esophageal varices （P = 0.017）. The area under the curve （AUC） for type Ⅳ collagen as determined by the receiver operating characteristic （ROC） for predicting esophageal varices was 0.78. CONCLUSION： This study suggests that the level of type Ⅳ collagen has a high diagnostic accuracy for the detection of esophageal varices in SAD.
文摘For understanding acoustic emission （AE） activity and accumulation of micro-damage inside rock under pure tensile state, the AE signals has been monitored on the test of directly tension on two kinds of marble specimens. A tensile constitutive model was proposed with the damage factor calculated by AE energy rate. The tensile strength of marble was discrete obviously and was sensitive to the inside microdefects and grain composition. With increasing of loading, the tensile stress-strain curve obviously showed nonlinear with the tensile tangent modulus decreasing. In repeated loading cycle, the tensile elastic modulus was less than that in the previous loading cycle because of the generation of micro damage during the prior loading. It means the linear weakening occurring in the specimens. The AE activity was corresponding with occurrence of nonlinear deformation. In the initial loading stage which only elastic deformation happened on the specimens, there were few AE events occurred; while when the nonlinear deformation happened with increasing of loading, lots of AE events were generated. The quantity and energy of AE events were proportionally related to the variation of tensile tangent modulus. The Kaiser effect of AE activity could be clearly observed in tensile cycle loading. Based on the theory of damage mechanics, the damage factor was defined by AE energy rate and the tensile damage constitutive model was proposed which only needed two property constants. The theoretical stress-strain curve was well fitted with the curve plotted with tested datum and the two property constants were easily gotten by the laboratory testing.
基金Supported by the Natural Science Foundation of Shanghai, No. 034119921
文摘AIM： To study the portal hemodynamics and their relationship with the size of esophageal varices seen at endoscopy and to evaluate whether these Doppler ultrasound parameters might predict variceal bleeding in patients with liver cirrhosis and portal hypertension. METHODS： One hundred and twenty cirrhotic patients with esophageal varices but without any previous bleeding were enrolled in the prospective study. During a 2-year observation period, 52 patients who had at least one episode of acute esophageal variceal hemorrhage constituted the bleeding group, and the remaining 68 patients without any previous hemorrhage constituted the non-bleeding group. All patients underwent endoscopy before or after color Doppler-ultrasonic examination, and images were interpreted independently by two endoscopists. The control group consisted of 30 healthy subjects, matched to the patient group in age and gender. Measurements of diameter, flow direction and flow velocity in the left gastric vein （LGV） and the portal vein （PV） were done in all patients and controls using color Doppler unit. After baseline measurements, 30 min after oral administration of 75 g glucose in 225 mL, changes of the diameter, flow velocity and direction in the PV and LGV were examined in 60 patients with esophageal varices and 15 healthy controls. RESULTS： The PV and LGV were detected successfully in 115 （96%） and 105 （88%） of 120 cirrhotic patients, respectively, and in 27 （90%） and 21 （70%） of 30 healthy controls, respectively. Among the 120 cirrhotic patients, 37 had F1, 59 had F2, and 24 had F3 grade varices. Compared with the healthy controls, cirrhotic group had a significantly lower velocity in the PV, a significantly greater diameter of the PV and LGV, and a higher velocity in the LGV. In the cirrhotic group, no difference in portal flow velocity and diameter were observed between patients with or without esophageal variceal bleeding （EVB）. However, the diameter and blood flow velocity of the LGV were significantly higher for EVB （＋） group compared with EVB （-） group （P〈0.01）. Diameter of the LGV increased with enlarged size of varices. There were differences between F1 and F2, F1 and F3 varices, but no differences between F2 and F3 varices （P = 0.125）. However, variceal bleeding was more frequent in patients with a diameter of LGV 〉6 mm. The flow velocity in the LGV of healthy controls was 8.70＋1.91 cm/s （n = 21）. In patients with liver cirrhosis, it was 10.3＋2.1 cm/s （n = 12） when the flow was hepatopetal and 13.5＋2.3 cm/s （n = 87） when it was hepatofugal. As the size of varices enlarged, hepatofugal flow velocity increased （P〈0.01） and was significantly different between patients with F1 and F2 varices and between patients with F2 and F3 varices. Variceal bleeding was more frequent in patients with a hepatofugal flow velocity 〉15 cm/s （32 of 52 patients, 61.5%）. Within the bleeding group, the mean LGV blood flow velocity was 16.6＋2.62 cm/s. No correlation was observed between the portal blood flow velocity and EVB. In all healthy controls, the flow direction in the LGV was hepatopetal, toward the PV. In patients with F1 varices, flow direction was hepatopetal in 10 patients, to-and-fro state in 3 patients, and hepatofugal in the remaining 18. The flow was hepatofugal in 91% patients with F2 and all F3 varices. Changes in diameter of the PV and LGV were not significant before and after ingestion of glucose （PV： 1.41＋1.5 cm before and 1.46＋1.6 cm after; LGV： 0.57＋1.7 cm before and 0.60＋1.5 cm after）. Flow direction in the LGV was hepatopetal and to-and-fro in 16 patients and hepatofugal in 44 patients before ingestion of glucose. Flow direction changed to hepatofugal in 9 of 16 patients with hepatopetal and to-and-fro blood flow after ingestion of glucose. In 44 patients with hepatofugal blood flow in the LGV, a significant increase in hepatofugal flow velocity was observed in 38 of 44 patients （86%） with esophageal varices. There was a relationship between the percentage changes in flow velocity and the size of varices. Patients who responded excessively to food ingestion might have a high risk for bleeding. The changes of blood flow velocity in the LGV were greater than those in the PV （LGV： 28.3＋26.1%, PV： 7.2＋13.2%, P〈0.01）, whereas no significant changes in the LGV occurred before and after ingestion of glucose in the control subjects. CONCLUSION： Hemodynamics of the PV is unrelated to the degree of endoscopic abnormalities in patients with liver cirrhosis. The most important combinations are endoscopic findings followed by the LGV hemodynamics. Duplex-Doppler ultrasonography has no value in the identification of patients with cirrhosis at risk of variceal bleeding. Hemodynamics of the LGV appears to be superior to those of the PV in predicting bleeding.
