A chlorothalonil(CTN)-degrading bacterial strain H4 was isolated in this study from a contaminated soil by continuous enrichment culture to identify its characteristics and to investigate its potential for remediation...A chlorothalonil(CTN)-degrading bacterial strain H4 was isolated in this study from a contaminated soil by continuous enrichment culture to identify its characteristics and to investigate its potential for remediation of CTN in contaminated soil. Based on the morphological, physiological and biochemical tests and 16 S r DNA sequence analysis, the strain was identified as Stenotrophomonas sp. After liquid culture for 7 d, 82.2% of CTN was removed by strain H4. The isolate could degrade CTN over a broad range of temperatures and p H values, and the optimum conditions for H4 degradation were p H 7.0 and 30℃. Reintroduction of the bacteria into artificially contaminated soil resulted in substantial removal of CTN(> 50%) after incubation for 14 d. Soil samples treated by H4 showed significant increases(P < 0.05) in soil dehydrogenase activity, soil polyphenol oxidase activity, average well-color development obtained by the Biolog Eco plate TM assay and Shannon-Weaver index, compared with the control. Strain H4 might be a promising candidate for application in the bioremediation of CTN-contaminated soils.展开更多
Gastrointestinal dysfunction in patients with cirrhosis may contribute to complications such as malnutrition and spontaneous bacterial peritonitis. To determine whether cirrhotic patients with ascites have altered int...Gastrointestinal dysfunction in patients with cirrhosis may contribute to complications such as malnutrition and spontaneous bacterial peritonitis. To determine whether cirrhotic patients with ascites have altered intestinal function, we compared intestinal permeability and absorption in patients with liver disease and normal subjects. Intestinal permeability and absorption were investigated in 66 cirrhotic patients (48 with ascites, 18 without ascites) and 74 healthy control subjects.Timed recovery of 3-O-methyl-D-glucose, D-xylose, L-rhamnose,and lactulose in urine following oral administration was measured in order to assess active and passive carrier-mediated,and nonmediated, absorptive capacity, as well as intestinal large-pore/small-pore (lactulose/rhamnose) permeability. Test sugars were measured by quantitative thin-layer chromatography and results are expressed as a percentage of test dose recovered in a 5 h urine collection. Sugar excretion ratios relating to small intestinal permeability (lactulose/rhamnose) and absorption (rhamnose/3-O-methyl-D-glucose)were calculated to avoid the effects of nonmucosal factors such as renal clearance,portal hypertension, and ascites on the recovery of sugarprobes in urine. Compared with normal subjects, the mean lactulose/rhamnose permeability ratio in cirrhotic patients with ascites was significantly higher (0.058 vs. 0.037, P< 0.001)but not in cirrhotic patients without ascites (0.041 vs. 0.037).Cirrhotic patients with ascites had significantly lower mean recoveries of 3-O-methyl-D-glucose (23.0 vs. 49.1% ; P < 0.001),D-xylose(18.8 vs. 34.5% ; P < 0.001), L-rhamnose (4.0 vs. 9.1% ; P < 0.001), and lactulose (0.202 vs. 0.337% ; P < 0.001) than normal subjects. However, the mean rhamnose/3-O-methyl-D-glucose ratio was the same in cirrhotic patients with ascites as normal subjects (0.189 vs. 0.189), indicating that the reduction in probe recovery was due to nonmucosal factors. Compared with normal subjects, cirrhotic patients with ascites have abnormal intestinal permeability,measured by urinary lactulose/rhamnose excretion, and normal small intestinal absorption,assessed by the urinary rhamnose/3-O-methyl-D-glucose ratio. Low urine recovery of sugar probes found in cirrhotic patients appears to be the result of nonintestinal factors affecting clearance rather than reduced intestinal absorption.展开更多
Objective: To determine whether Mexican American women with polycystic ovary syndrome (PCOS), a population more insulin resistant than white women with PCOS, demonstrate differences in adrenal androgen production. Des...Objective: To determine whether Mexican American women with polycystic ovary syndrome (PCOS), a population more insulin resistant than white women with PCOS, demonstrate differences in adrenal androgen production. Design: Retrospective study. Setting: University gynecology clinic and research laboratory. Patient(s): One hundred eleven white women and 50 Mexican American women with PCOS based on the 2003 Rotterdam Consensus Statement. Intervention(s): Blood sampling, oral glucose tolerance testing, and ultrasonography. Main Outcome Measure(s): Serum total T, free T, DHEAS, and calculation of multiple insulin sensitivity indices after an oral glucose challenge. Result(s): Mexican American women with PCOS were significantly more insulin resistant than their white counterparts but had lower circulating levels of DHEAS, a reliable index of adrenal androgen production. Age and body mass index (BMI) were each inversely proportional to serum DHEAS, but no association was found between circulating insulin and serum DHEAS levels. Testosterone levels were similar between groups. Conclusion(s): The lower levels of DHEAS observed in the more insulin resistant Mexican American group with PCOS (compared to a similar group of white women living in the same locale) further corroborates the extent of phenotypic variability among specific PCOS populations. Hyperinsulinemia does not appear to significantly influence circulating adrenal androgen levels in PCOS.展开更多
Several authors have considered observability problems for the heat equation and relatedpartial differential equations.A basic problem is to determine what kinds of sampling providesufficient information to uniquely d...Several authors have considered observability problems for the heat equation and relatedpartial differential equations.A basic problem is to determine what kinds of sampling providesufficient information to uniquely determine the initial heat distribntion.We address the case wherethe temperature is measured while travelling along a curve.We consider the special case where the space is a flat torus(of arbitrary dimension)and thecurve is a geodesic.It is shown that,in this case,the observed temperature is sufficient informationto uniquely determine the initial heat distribution if and only if the geodesic is dense in the torus.In the case of a torus,Fourier analysis techniques can be used to write down the solution of theheat equation.This allows us to derive an explicit representation of the observed temperature interms of the initial distribution.We use this representation and some ideas from the theory ofalmost periodic functions to show that the Fourier coefficients of the initial distribution can berecovered from the observation.展开更多
ⅠMore than fifty years ago, Henri Cartant ~j suggested that geometric function theory ofone complex variable should be extended to biholomorphic mappings of several complexvariables. In particular, he cited the speci...ⅠMore than fifty years ago, Henri Cartant ~j suggested that geometric function theory ofone complex variable should be extended to biholomorphic mappings of several complexvariables. In particular, he cited the special classes of starlike and convex mappings asappropriate topics for generalization. In noting some of the difficulties of generalization, hepointed out the Growth Theorem as one of the results that would not extend to thepolydisc (nor to the ball). Also, he observed that for normalized biholomorphic展开更多
基金Supported by the Public Service Special Project of the Environmental Protection Ministry of China(No.201109018)
文摘A chlorothalonil(CTN)-degrading bacterial strain H4 was isolated in this study from a contaminated soil by continuous enrichment culture to identify its characteristics and to investigate its potential for remediation of CTN in contaminated soil. Based on the morphological, physiological and biochemical tests and 16 S r DNA sequence analysis, the strain was identified as Stenotrophomonas sp. After liquid culture for 7 d, 82.2% of CTN was removed by strain H4. The isolate could degrade CTN over a broad range of temperatures and p H values, and the optimum conditions for H4 degradation were p H 7.0 and 30℃. Reintroduction of the bacteria into artificially contaminated soil resulted in substantial removal of CTN(> 50%) after incubation for 14 d. Soil samples treated by H4 showed significant increases(P < 0.05) in soil dehydrogenase activity, soil polyphenol oxidase activity, average well-color development obtained by the Biolog Eco plate TM assay and Shannon-Weaver index, compared with the control. Strain H4 might be a promising candidate for application in the bioremediation of CTN-contaminated soils.
文摘Gastrointestinal dysfunction in patients with cirrhosis may contribute to complications such as malnutrition and spontaneous bacterial peritonitis. To determine whether cirrhotic patients with ascites have altered intestinal function, we compared intestinal permeability and absorption in patients with liver disease and normal subjects. Intestinal permeability and absorption were investigated in 66 cirrhotic patients (48 with ascites, 18 without ascites) and 74 healthy control subjects.Timed recovery of 3-O-methyl-D-glucose, D-xylose, L-rhamnose,and lactulose in urine following oral administration was measured in order to assess active and passive carrier-mediated,and nonmediated, absorptive capacity, as well as intestinal large-pore/small-pore (lactulose/rhamnose) permeability. Test sugars were measured by quantitative thin-layer chromatography and results are expressed as a percentage of test dose recovered in a 5 h urine collection. Sugar excretion ratios relating to small intestinal permeability (lactulose/rhamnose) and absorption (rhamnose/3-O-methyl-D-glucose)were calculated to avoid the effects of nonmucosal factors such as renal clearance,portal hypertension, and ascites on the recovery of sugarprobes in urine. Compared with normal subjects, the mean lactulose/rhamnose permeability ratio in cirrhotic patients with ascites was significantly higher (0.058 vs. 0.037, P< 0.001)but not in cirrhotic patients without ascites (0.041 vs. 0.037).Cirrhotic patients with ascites had significantly lower mean recoveries of 3-O-methyl-D-glucose (23.0 vs. 49.1% ; P < 0.001),D-xylose(18.8 vs. 34.5% ; P < 0.001), L-rhamnose (4.0 vs. 9.1% ; P < 0.001), and lactulose (0.202 vs. 0.337% ; P < 0.001) than normal subjects. However, the mean rhamnose/3-O-methyl-D-glucose ratio was the same in cirrhotic patients with ascites as normal subjects (0.189 vs. 0.189), indicating that the reduction in probe recovery was due to nonmucosal factors. Compared with normal subjects, cirrhotic patients with ascites have abnormal intestinal permeability,measured by urinary lactulose/rhamnose excretion, and normal small intestinal absorption,assessed by the urinary rhamnose/3-O-methyl-D-glucose ratio. Low urine recovery of sugar probes found in cirrhotic patients appears to be the result of nonintestinal factors affecting clearance rather than reduced intestinal absorption.
文摘Objective: To determine whether Mexican American women with polycystic ovary syndrome (PCOS), a population more insulin resistant than white women with PCOS, demonstrate differences in adrenal androgen production. Design: Retrospective study. Setting: University gynecology clinic and research laboratory. Patient(s): One hundred eleven white women and 50 Mexican American women with PCOS based on the 2003 Rotterdam Consensus Statement. Intervention(s): Blood sampling, oral glucose tolerance testing, and ultrasonography. Main Outcome Measure(s): Serum total T, free T, DHEAS, and calculation of multiple insulin sensitivity indices after an oral glucose challenge. Result(s): Mexican American women with PCOS were significantly more insulin resistant than their white counterparts but had lower circulating levels of DHEAS, a reliable index of adrenal androgen production. Age and body mass index (BMI) were each inversely proportional to serum DHEAS, but no association was found between circulating insulin and serum DHEAS levels. Testosterone levels were similar between groups. Conclusion(s): The lower levels of DHEAS observed in the more insulin resistant Mexican American group with PCOS (compared to a similar group of white women living in the same locale) further corroborates the extent of phenotypic variability among specific PCOS populations. Hyperinsulinemia does not appear to significantly influence circulating adrenal androgen levels in PCOS.
文摘Several authors have considered observability problems for the heat equation and relatedpartial differential equations.A basic problem is to determine what kinds of sampling providesufficient information to uniquely determine the initial heat distribntion.We address the case wherethe temperature is measured while travelling along a curve.We consider the special case where the space is a flat torus(of arbitrary dimension)and thecurve is a geodesic.It is shown that,in this case,the observed temperature is sufficient informationto uniquely determine the initial heat distribution if and only if the geodesic is dense in the torus.In the case of a torus,Fourier analysis techniques can be used to write down the solution of theheat equation.This allows us to derive an explicit representation of the observed temperature interms of the initial distribution.We use this representation and some ideas from the theory ofalmost periodic functions to show that the Fourier coefficients of the initial distribution can berecovered from the observation.
文摘ⅠThe classical distortion theorems for families of univalent functions have been studied not later than 1907 when Kbe discovered his 'Verzerrangsatz'.
文摘ⅠMore than fifty years ago, Henri Cartant ~j suggested that geometric function theory ofone complex variable should be extended to biholomorphic mappings of several complexvariables. In particular, he cited the special classes of starlike and convex mappings asappropriate topics for generalization. In noting some of the difficulties of generalization, hepointed out the Growth Theorem as one of the results that would not extend to thepolydisc (nor to the ball). Also, he observed that for normalized biholomorphic
