AIM: To study the sensitivity of gastric smooth muscle to C-type natriuretic peptide (CNP) in streptozotocin (STZ)-induced diabetic rats. METHODS: The spontaneous contraction of a gastric smooth muscle strip was recor...AIM: To study the sensitivity of gastric smooth muscle to C-type natriuretic peptide (CNP) in streptozotocin (STZ)-induced diabetic rats. METHODS: The spontaneous contraction of a gastric smooth muscle strip was recorded by using physiological methods in rats. The expressions of CNP and natriuretic peptide receptor-B (NPR-B) in gastric tissue were examined by using immunohistochemistry techniques in the diabetic rat. RESULTS: At 4 wk after injection of STZ and vehicle, the frequency of spontaneous contraction of gastric smooth muscle was significantly reduced in diabetic rats, and the frequency was decreased from 3.10 ± 0.14 cycle/min in controls to 2.23 ± 0.13 cycle/min (n = 8, P < 0.01). However, the amplitude of spontaneous contraction was not significant different from the normal rat. CNP significantly inhibited spontaneous contraction of gastric smooth muscle in normal and diabetic rats, but the inhibitory effect was significantly potentiated in the diabetic rats. The amplitudes of spontaneous contraction were suppressed by 75.15% ± 0.71% and 58.92% ± 1.32% while the frequencies were decreased by 53.33% ± 2.03% and 26.95% ± 2.82% in diabetic and normal rats, respectively (n = 8, P < 0.01). The expression of CNP in gastric tissue was not changed in diabetic rats, however the expression of NPR-B was significantly increased in diabetic rats, and the staining indexes of NPR-B were 30.67 ± 1.59 and 17.63 ± 1.49 in diabetic and normal rat, respectively (n = 8, P < 0.01).CONCLUSION: The results suggest that CNP induced an inhibitory effect on spontaneous contraction of gastric smooth muscle, potentiated in diabetic rat via up-regulation of the natriuretic peptides-NPR-B-particulate guanylyl cyclase-cyclic GMP signal pathway.展开更多
Given an m-sequence, the main factor influencing the least period of the Generalized Self-Shrinking （GSS） sequence is the selection of the linear combining vector G. Based on the calculation of the minimal polynomia...Given an m-sequence, the main factor influencing the least period of the Generalized Self-Shrinking （GSS） sequence is the selection of the linear combining vector G. Based on the calculation of the minimal polynomial ofL GSS sequences and the comparison of their degrees, an algorithm for selecting the linear combining vector G is presented, which is simple to understand, to implement and to prove. By using this method, much more than 2^L-l linear combining vectors G of the desired properties will be resulted. Thus in the practical application the linear combining vector G can be chosen with great arbitrariness. Additionally, this algorithm can be extended to any finite field easily.展开更多
Investigations on the effects of W/C ratio and silica fume on the autogenous shrinkage and internal relative humidity of high performance concrete (HPC), and analysis of the self-desiccation mechanisms of HPC showed t...Investigations on the effects of W/C ratio and silica fume on the autogenous shrinkage and internal relative humidity of high performance concrete (HPC), and analysis of the self-desiccation mechanisms of HPC showed that the autogenous shrinkage and internal relative humidity of HPC increases and decreases with the reduction of W/C respectively; and that these phenomena were amplified by the addition of silica fume. Theoretical analyses indicated that the reduction of RH in HPC was not due to shortage of water, but due to the fact that the evaporable water in HPC was not evaporated freely. The reduction of internal relative humidity or the so-called self-desiccation of HPC was chiefly caused by the increase in mole concentration of soluble ions in HPC and the reduction of pore size or the increase in the fraction of micro-pore water in the total evaporable water (Tr/Tte ratio).展开更多
It is known that the slabs on soil constitute one of the most difficult types of structures despite their apparent simplicity. The objective of this paper is to give a general survey of the design of ground supported ...It is known that the slabs on soil constitute one of the most difficult types of structures despite their apparent simplicity. The objective of this paper is to give a general survey of the design of ground supported slabs with the interposition of a suitable subbase. A solution is proposed with the following characteristics： （1） complete suppression of joints; （2） conventional reinforcement with meshes in the upper and lower fiber of the slab in order to confront and distribute cracking that is caused by hindrance of free contractions and expansions; （3） effective confrontation of problems of bulging. The proposal is in effect on one hand for industrial floorings and on the other hand for concrete pavings with large durability requirement.展开更多
By End（G） and hEnd（G） we denote the set of endomorphisms and half-strong endomorphisms of a graph G respectively. A graph G is said to be E-H-unretractive if End（G） = hEnd（G）. A general characterization of an ...By End（G） and hEnd（G） we denote the set of endomorphisms and half-strong endomorphisms of a graph G respectively. A graph G is said to be E-H-unretractive if End（G） = hEnd（G）. A general characterization of an E-H-unretractive graph seems to be difficult. In this paper, bipartite graphs with E-H-unretractivity are characterized explicitly.展开更多
基金Supported by The National Natural Science Foundation of China, No. 30760068
文摘AIM: To study the sensitivity of gastric smooth muscle to C-type natriuretic peptide (CNP) in streptozotocin (STZ)-induced diabetic rats. METHODS: The spontaneous contraction of a gastric smooth muscle strip was recorded by using physiological methods in rats. The expressions of CNP and natriuretic peptide receptor-B (NPR-B) in gastric tissue were examined by using immunohistochemistry techniques in the diabetic rat. RESULTS: At 4 wk after injection of STZ and vehicle, the frequency of spontaneous contraction of gastric smooth muscle was significantly reduced in diabetic rats, and the frequency was decreased from 3.10 ± 0.14 cycle/min in controls to 2.23 ± 0.13 cycle/min (n = 8, P < 0.01). However, the amplitude of spontaneous contraction was not significant different from the normal rat. CNP significantly inhibited spontaneous contraction of gastric smooth muscle in normal and diabetic rats, but the inhibitory effect was significantly potentiated in the diabetic rats. The amplitudes of spontaneous contraction were suppressed by 75.15% ± 0.71% and 58.92% ± 1.32% while the frequencies were decreased by 53.33% ± 2.03% and 26.95% ± 2.82% in diabetic and normal rats, respectively (n = 8, P < 0.01). The expression of CNP in gastric tissue was not changed in diabetic rats, however the expression of NPR-B was significantly increased in diabetic rats, and the staining indexes of NPR-B were 30.67 ± 1.59 and 17.63 ± 1.49 in diabetic and normal rat, respectively (n = 8, P < 0.01).CONCLUSION: The results suggest that CNP induced an inhibitory effect on spontaneous contraction of gastric smooth muscle, potentiated in diabetic rat via up-regulation of the natriuretic peptides-NPR-B-particulate guanylyl cyclase-cyclic GMP signal pathway.
基金Supported in part by the National Natural Science Foun-dation of China (No.60273084) and Doctoral Foundation (No.20020701013).
文摘Given an m-sequence, the main factor influencing the least period of the Generalized Self-Shrinking （GSS） sequence is the selection of the linear combining vector G. Based on the calculation of the minimal polynomial ofL GSS sequences and the comparison of their degrees, an algorithm for selecting the linear combining vector G is presented, which is simple to understand, to implement and to prove. By using this method, much more than 2^L-l linear combining vectors G of the desired properties will be resulted. Thus in the practical application the linear combining vector G can be chosen with great arbitrariness. Additionally, this algorithm can be extended to any finite field easily.
文摘Investigations on the effects of W/C ratio and silica fume on the autogenous shrinkage and internal relative humidity of high performance concrete (HPC), and analysis of the self-desiccation mechanisms of HPC showed that the autogenous shrinkage and internal relative humidity of HPC increases and decreases with the reduction of W/C respectively; and that these phenomena were amplified by the addition of silica fume. Theoretical analyses indicated that the reduction of RH in HPC was not due to shortage of water, but due to the fact that the evaporable water in HPC was not evaporated freely. The reduction of internal relative humidity or the so-called self-desiccation of HPC was chiefly caused by the increase in mole concentration of soluble ions in HPC and the reduction of pore size or the increase in the fraction of micro-pore water in the total evaporable water (Tr/Tte ratio).
文摘It is known that the slabs on soil constitute one of the most difficult types of structures despite their apparent simplicity. The objective of this paper is to give a general survey of the design of ground supported slabs with the interposition of a suitable subbase. A solution is proposed with the following characteristics： （1） complete suppression of joints; （2） conventional reinforcement with meshes in the upper and lower fiber of the slab in order to confront and distribute cracking that is caused by hindrance of free contractions and expansions; （3） effective confrontation of problems of bulging. The proposal is in effect on one hand for industrial floorings and on the other hand for concrete pavings with large durability requirement.
基金the National Natural Science Foundation of China （No. 10671122）.Acknowledgement The author would like to thank Professor Dr. U.Knauer for valuable advice and helpful comments on this paper.
文摘By End（G） and hEnd（G） we denote the set of endomorphisms and half-strong endomorphisms of a graph G respectively. A graph G is said to be E-H-unretractive if End（G） = hEnd（G）. A general characterization of an E-H-unretractive graph seems to be difficult. In this paper, bipartite graphs with E-H-unretractivity are characterized explicitly.
