AIM:To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS:For the development of liver cirrhosis and portal hypertens...AIM:To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS:For the development of liver cirrhosis and portal hypertensive gastropathy,60 rats underwent ligation of the left adrenal vein and complete devascularization of the left renal vein,followed by phenobarbital and carbon tetrachloride(CCl4) administration.After two weeks of CCl4 administration, the rats were randomly separated into two groups.In group A,propranolol was continuously administered intragastrically throughout the study,whereas in group B normal saline(placebo)was administered instead. Hemodynamic studies and vascular morphometric analysis of gastric sections were performed after complete induction of cirrhosis. RESULTS:Vascular morphometric studies showed higher numbers of vessels in all mucosal layers in the control group.Statistical analysis revealed a significantly higher total vascular surface in the control group compared to the propranolol group,but with no statistically significant difference between the mean vascular surfaces between the groups.Our study clearly shows that the increased mucosal blood flow is manifested by a marked increase of vessel count. CONCLUSION:Early propranolol's administration in portal hypertensive cirrhotic rats seems to prevent intense gastric vascular congestion that characterizes portal hypertensive gastropathy.展开更多
To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in C...To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO_2-enriched(1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO_2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment(pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control(p H 8.3)(84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment(11.7%). Results suggest that future ocean acidification(OA) would cause detrimental effects on the early development of A. irradias.展开更多
The effects of quality and content of fly ash on the early-age cracking behavior of high-flowing concrete （HFC） were investigated. The early-age cracking behavior of the HFC was analyzed by combining the tests of ev...The effects of quality and content of fly ash on the early-age cracking behavior of high-flowing concrete （HFC） were investigated. The early-age cracking behavior of the HFC was analyzed by combining the tests of evaporation capacity and electrical resistivity of the HFC. In these tests, a modified flat-type specimen was adopted. The results show that the HFC will have a lower evaporation capacity when it is mixed with fine fly ash, while it will have a higher evaporation capacity when grade II! fly ash is used as mineral admixture. And the electrical resistivity rate of HFC reduces with the increase of the content of fly ash. A nonlinear relationship exists between the cracking time of HFC and the minimum electrical resistivity. The early-age cracking behavior of HFC with fly ash can be enhanced by appropriately increasing the fine particle content and MgO, K2O, and SO3 contents of fly ash. The optimal content of fly ash, which makes a satisfied early-age cracking behavior of HFC, is obtained. And when the content of fly ash exceeds a critical value, the early-age cracking behavior of HFC will rapidly decrease.展开更多
文摘AIM:To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS:For the development of liver cirrhosis and portal hypertensive gastropathy,60 rats underwent ligation of the left adrenal vein and complete devascularization of the left renal vein,followed by phenobarbital and carbon tetrachloride(CCl4) administration.After two weeks of CCl4 administration, the rats were randomly separated into two groups.In group A,propranolol was continuously administered intragastrically throughout the study,whereas in group B normal saline(placebo)was administered instead. Hemodynamic studies and vascular morphometric analysis of gastric sections were performed after complete induction of cirrhosis. RESULTS:Vascular morphometric studies showed higher numbers of vessels in all mucosal layers in the control group.Statistical analysis revealed a significantly higher total vascular surface in the control group compared to the propranolol group,but with no statistically significant difference between the mean vascular surfaces between the groups.Our study clearly shows that the increased mucosal blood flow is manifested by a marked increase of vessel count. CONCLUSION:Early propranolol's administration in portal hypertensive cirrhotic rats seems to prevent intense gastric vascular congestion that characterizes portal hypertensive gastropathy.
基金supported by the National Natural Science Foundation of China (31101875)the Specialized Research Fund for the Doctoral Program of Higher Education of China (20110132120027)
文摘To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO_2-enriched(1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO_2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment(pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control(p H 8.3)(84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment(11.7%). Results suggest that future ocean acidification(OA) would cause detrimental effects on the early development of A. irradias.
基金Project(50478003)supported by the National Natural Science Foundation of ChinaProject(2002F007)supported by the Natural Science Foundation of Fujian Province,China
文摘The effects of quality and content of fly ash on the early-age cracking behavior of high-flowing concrete （HFC） were investigated. The early-age cracking behavior of the HFC was analyzed by combining the tests of evaporation capacity and electrical resistivity of the HFC. In these tests, a modified flat-type specimen was adopted. The results show that the HFC will have a lower evaporation capacity when it is mixed with fine fly ash, while it will have a higher evaporation capacity when grade II! fly ash is used as mineral admixture. And the electrical resistivity rate of HFC reduces with the increase of the content of fly ash. A nonlinear relationship exists between the cracking time of HFC and the minimum electrical resistivity. The early-age cracking behavior of HFC with fly ash can be enhanced by appropriately increasing the fine particle content and MgO, K2O, and SO3 contents of fly ash. The optimal content of fly ash, which makes a satisfied early-age cracking behavior of HFC, is obtained. And when the content of fly ash exceeds a critical value, the early-age cracking behavior of HFC will rapidly decrease.
