An optimal algorithm for the retrieval of chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary was established with the optical parameters derived from the in-situ data obtained ...An optimal algorithm for the retrieval of chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary was established with the optical parameters derived from the in-situ data obtained in Jan. 2003 in the same area. And then, the chlorophyll, suspended sediments and gelbstoff of the SeaWiFS pixels on Jan. 29, 2003 corresponding to the in-situ sites of Jan. 25 and 26, 2003 were synchronously retrieved, with average relative errors of 14.9%, 12.1% and 13.6% for chlorophyll, suspended sediments and gelbstoff, respectively. The research results indicated that the optimal retrieval algorithm established here was relatively fit for the retrieval of the chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary, and had quite good retrieval accuracy.展开更多
Aim and methods The study of three-dimensional quantitative structure-activity relationship （3D-QSAR） of DDPH and its derivatives has been performed using Apex-3D programme. Results The result indicates that substit...Aim and methods The study of three-dimensional quantitative structure-activity relationship （3D-QSAR） of DDPH and its derivatives has been performed using Apex-3D programme. Results The result indicates that substituents of para- and ortho-positions in phenyl ring of aryloxyalkylamine greatly influence the bioactivity. Conclusion The biophore model and 3D-QSAR equation help us not only further understand receptor-ligand interactions, but also design new compounds with better bioactivity.展开更多
Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru...Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru/C and a base,which afforded high yields of phenolic monomers from the lignin component and a solid carbohydrate pulp,is reported.The introduction of Cs_(2)CO_(3) led to the generation of C2 side‐chained phenols through the cleavage of C_(β)–O and C_(β)–C_(γ) bonds inβ–O–4 units in addition to C3 side‐chained phenols;the relationship between C2 and C3 was dependent on the base dosage.The reaction conditions,including base species,temperature,time,and H_(2) pressure,were optimized in terms of phenolic product distribution,delignification degree,and carbohydrate retention.The carbohydrate pulps generated from reductive catalytic fractionation in the presence of Cs_(2)CO_(3) were more amenable to enzymatic hydrolysis,indicating that this treatment of biomass constituted the fractionation of biomass components together with the breakdown of biomass recalcitrance.展开更多
lntracellular redox homeostasis plays a critical role in determining tumor cells＇ sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 （TRX1）, a key component of redox regulation, i...lntracellular redox homeostasis plays a critical role in determining tumor cells＇ sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 （TRX1）, a key component of redox regulation, in arsenic trioxide （AS2O3）-induced apoptosis. Over-expression of wild-type TRX1 in HepG2 cells led to the inhibition of As2O3-induced cytochrome c （cyto c） release, caspase activation and apoptosis, and down-regulation of TRX1 expression by RNAi sensitized HepG2 cells to As2O3-induced apoptosis. Interestingly, mutation of the active site of TRX1 from Cys^32/35 to Ser^32/35 converted this molecule from an apoptotic protector to an apoptotic promoter. In an effort to understand the mechanisms of this conversion, we used isolated mitochondria from mouse liver and found that recombinant wild-type TRX1 could protect mitochondria from the apoptotic changes. In contrast, the mutant form of TRX1 alone elicited mitochondria-related apoptotic changes, including the mitochondrial permeability transition pore （mPTP） opening, loss of mitochondrial membrane potential, and cyto c release from mitochondria. These apoptotic effects were inhibited by cyclosporine A （CsA）, indicating that mutant TRX1 targeted to mPTP. Alteration of TRX1 from its reduced form to oxidized form in vivo by 2,4-dinitrochlorobenzene （DNCB）, a specific inhibitor ofTRX reductase, also sensitized HepG2 cells to As203-induced apoptosis. These data suggest that TRX1 plays a central role in regulating apoptosis by blocking cyto c release, and inactivation of TRX1 by either mutation or oxidization of the active site cysteines may sensitize tumor cells to As2O3-induced apoptosis.展开更多
AIM： To investigate the risk factors for gallstone disease in the general population of Chengdu, China. METHODS： This study was conducted at the West China Hospital. Subjects who received a physical examination at t...AIM： To investigate the risk factors for gallstone disease in the general population of Chengdu, China. METHODS： This study was conducted at the West China Hospital. Subjects who received a physical examination at this hospital between January and December 2007 were included. Body mass index, blood pressure, fasting plasma glucose, serum lipid and lipoproteins concentrations were analyzed. Gallstone disease was diagnosed by ultrasound or on the basis of a history of cholecystectomy because of gallstone disease. Unconditional logistic regression analysis was used to investigate the risk factors for gallstone disease, and the Chi-square test was used to analyze differences in the incidence of metabolic disorders between subjects with and without gallstone disease. RESULTS： A total of 3573 people were included, 10.7% （384/3573） of whom had gallstone diseases. Multiple logistic regression analysis indicated that the incidence of gallstone disease in subjects aged 40-64 or ≥65 years was significantly different from that in those aged 18-39 years （P 〈 0.05）; the incidence was higher in women than in men （P 〈 0.05）. In men,a high level of fasting plasma glucose was obvious in gallstone disease （P 〈 0.05）, and in women, hypertriglyceridemia or obesity were significant in gallstone disease （P 〈 0.05）. CONCLUSION： We assume that age and sex are profoundly associated with the incidence of gallstone disease; the metabolic risk factors for gallstone disease were different between men and women.展开更多
A dual wavelength differential first derivative spectrophotometric method has been developed to standardize the concentration of a saturated aqueous solution of carbon monoxide (CO) as the standard and to identify and...A dual wavelength differential first derivative spectrophotometric method has been developed to standardize the concentration of a saturated aqueous solution of carbon monoxide (CO) as the standard and to identify and to determine CO formed during the microsomal metabolism of xenobiotics in vitro. The method can significantly eliminate the background interference in the assay media and increase the quantitative accuracy and the sensitivity. There is a good linear relationship between CO concentration in the range of 2～10 μmol·L 1 CO and the distance D between the first derivative peak at 415 nm amd valley at 426 nm with r=0.9999(n=5),the regression equation being C (mmol·L 1 )=17.6D 0.4, the detection limit lower than 0.1 μmol·L 1 CO. The average recoveries of CO from the assay system and the sample were 102.1%, RSD=2.9% (n=7) and 79.7%, RSD=6.8% (n=12),respectively. The RSD of within day was 4.4%(n=18),and the RSD of day to day was 6.1%(n=16). By this method, four trihaloanilines and one trihalobenzene were tested, the results showed that only 2,4,5 trifluoroaniline could be converted to CO by the incubation with rat hepatic microsomes, NADPH and oxygen, the ability of phenobarbital or dexamethasone to induce rat hepatic microsomes to catalyze CO formation was 3 or 8 times higher than that of the control.展开更多
In the present article, we report the screening-dependent study of the superconducting state parameters （SSPs）, viz. electron-phonon coupling strength A, Coulomb pseudopotential μ^＊, transition temperature TC, iso...In the present article, we report the screening-dependent study of the superconducting state parameters （SSPs）, viz. electron-phonon coupling strength A, Coulomb pseudopotential μ^＊, transition temperature TC, isotope effect exponent a, and effective interaction strength No V of 3d-band transition metals binary alloys superconductors have been made extensively in the present work using a model potential formalism and employing the pseudo-alloy-atom （PAA） model for the first time. Five local field correction functions proposed by Hartree （H）, Taylor （T）, Ichimaru-Utsumi （IU）, Farid et al. （F） and Sarkar et al. （S） are used in the present investigation to study the screening influence on the aforesaid properties. The present results of the SSPs obtained from H-screening are found in qualitative agreement with the available experimental data wherever exist.展开更多
Properties of the triaxial superdeformed （TSD） bands of odd-A Lu isotopes are investigated systematically within the supersymmetry scheme including many-body interactions and a perturbation possessing the S0（5） （...Properties of the triaxial superdeformed （TSD） bands of odd-A Lu isotopes are investigated systematically within the supersymmetry scheme including many-body interactions and a perturbation possessing the S0（5） （or SU（5）） symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia and the spin of the TSD bands in odd-A Lu isotopes are obtained. The calculation shows that the competition between the pairing and anti-pairing effects exists in these TSD bands. Meanwhile, the SU（3） symmetry in TSD bands are broken more seriously than in superdeformed （SD） bands.展开更多
Through a sampling analysis of trace elements and REE in the section of Middle Permian Zhesi Formation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are characterized by L...Through a sampling analysis of trace elements and REE in the section of Middle Permian Zhesi Formation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are characterized by LREE-enrichment. By analysis of the discriminant index of the sedimentary environment,the tectonic setting of Zhesi Formation is determined to be a continental island arc environment. Meanwhile,according to the sedimentary structure and lithology combination,Zhesi Formation is divided into the neritic-bathyal retention-reduction environment as well as the delta front and prodelta sedimentary systems.展开更多
A novel algorithm to voxelize 3D mesh models with gray levels is presented in this paper.The key innovation of our method is to decide the gray level of a voxel according to the total area of all surfaces contained by...A novel algorithm to voxelize 3D mesh models with gray levels is presented in this paper.The key innovation of our method is to decide the gray level of a voxel according to the total area of all surfaces contained by it.During the preprocessing stage,a set of voxels in the extended bounding box of each triangle is established.Then we travel each triangle and compute the areas between it and its set of voxels one by one.Finally,each voxel is arranged a discrete gray level from 0 to 255.Experiments show that our algorithm gets a comparatively perfect result compared with the prevenient ones and approaches the original models in a more accurate way.展开更多
文摘An optimal algorithm for the retrieval of chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary was established with the optical parameters derived from the in-situ data obtained in Jan. 2003 in the same area. And then, the chlorophyll, suspended sediments and gelbstoff of the SeaWiFS pixels on Jan. 29, 2003 corresponding to the in-situ sites of Jan. 25 and 26, 2003 were synchronously retrieved, with average relative errors of 14.9%, 12.1% and 13.6% for chlorophyll, suspended sediments and gelbstoff, respectively. The research results indicated that the optimal retrieval algorithm established here was relatively fit for the retrieval of the chlorophyll, suspended sediments and gelbstoff of case Ⅱ waters in the Pearl River estuary, and had quite good retrieval accuracy.
文摘Aim and methods The study of three-dimensional quantitative structure-activity relationship （3D-QSAR） of DDPH and its derivatives has been performed using Apex-3D programme. Results The result indicates that substituents of para- and ortho-positions in phenyl ring of aryloxyalkylamine greatly influence the bioactivity. Conclusion The biophore model and 3D-QSAR equation help us not only further understand receptor-ligand interactions, but also design new compounds with better bioactivity.
文摘Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru/C and a base,which afforded high yields of phenolic monomers from the lignin component and a solid carbohydrate pulp,is reported.The introduction of Cs_(2)CO_(3) led to the generation of C2 side‐chained phenols through the cleavage of C_(β)–O and C_(β)–C_(γ) bonds inβ–O–4 units in addition to C3 side‐chained phenols;the relationship between C2 and C3 was dependent on the base dosage.The reaction conditions,including base species,temperature,time,and H_(2) pressure,were optimized in terms of phenolic product distribution,delignification degree,and carbohydrate retention.The carbohydrate pulps generated from reductive catalytic fractionation in the presence of Cs_(2)CO_(3) were more amenable to enzymatic hydrolysis,indicating that this treatment of biomass constituted the fractionation of biomass components together with the breakdown of biomass recalcitrance.
文摘lntracellular redox homeostasis plays a critical role in determining tumor cells＇ sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 （TRX1）, a key component of redox regulation, in arsenic trioxide （AS2O3）-induced apoptosis. Over-expression of wild-type TRX1 in HepG2 cells led to the inhibition of As2O3-induced cytochrome c （cyto c） release, caspase activation and apoptosis, and down-regulation of TRX1 expression by RNAi sensitized HepG2 cells to As2O3-induced apoptosis. Interestingly, mutation of the active site of TRX1 from Cys^32/35 to Ser^32/35 converted this molecule from an apoptotic protector to an apoptotic promoter. In an effort to understand the mechanisms of this conversion, we used isolated mitochondria from mouse liver and found that recombinant wild-type TRX1 could protect mitochondria from the apoptotic changes. In contrast, the mutant form of TRX1 alone elicited mitochondria-related apoptotic changes, including the mitochondrial permeability transition pore （mPTP） opening, loss of mitochondrial membrane potential, and cyto c release from mitochondria. These apoptotic effects were inhibited by cyclosporine A （CsA）, indicating that mutant TRX1 targeted to mPTP. Alteration of TRX1 from its reduced form to oxidized form in vivo by 2,4-dinitrochlorobenzene （DNCB）, a specific inhibitor ofTRX reductase, also sensitized HepG2 cells to As203-induced apoptosis. These data suggest that TRX1 plays a central role in regulating apoptosis by blocking cyto c release, and inactivation of TRX1 by either mutation or oxidization of the active site cysteines may sensitize tumor cells to As2O3-induced apoptosis.
基金The National Natural Science Foundation of China,No.30571640the National Basic Research Program of China,No.2006CB504302 and No.2007CB512902
文摘AIM： To investigate the risk factors for gallstone disease in the general population of Chengdu, China. METHODS： This study was conducted at the West China Hospital. Subjects who received a physical examination at this hospital between January and December 2007 were included. Body mass index, blood pressure, fasting plasma glucose, serum lipid and lipoproteins concentrations were analyzed. Gallstone disease was diagnosed by ultrasound or on the basis of a history of cholecystectomy because of gallstone disease. Unconditional logistic regression analysis was used to investigate the risk factors for gallstone disease, and the Chi-square test was used to analyze differences in the incidence of metabolic disorders between subjects with and without gallstone disease. RESULTS： A total of 3573 people were included, 10.7% （384/3573） of whom had gallstone diseases. Multiple logistic regression analysis indicated that the incidence of gallstone disease in subjects aged 40-64 or ≥65 years was significantly different from that in those aged 18-39 years （P 〈 0.05）; the incidence was higher in women than in men （P 〈 0.05）. In men,a high level of fasting plasma glucose was obvious in gallstone disease （P 〈 0.05）, and in women, hypertriglyceridemia or obesity were significant in gallstone disease （P 〈 0.05）. CONCLUSION： We assume that age and sex are profoundly associated with the incidence of gallstone disease; the metabolic risk factors for gallstone disease were different between men and women.
文摘A dual wavelength differential first derivative spectrophotometric method has been developed to standardize the concentration of a saturated aqueous solution of carbon monoxide (CO) as the standard and to identify and to determine CO formed during the microsomal metabolism of xenobiotics in vitro. The method can significantly eliminate the background interference in the assay media and increase the quantitative accuracy and the sensitivity. There is a good linear relationship between CO concentration in the range of 2～10 μmol·L 1 CO and the distance D between the first derivative peak at 415 nm amd valley at 426 nm with r=0.9999(n=5),the regression equation being C (mmol·L 1 )=17.6D 0.4, the detection limit lower than 0.1 μmol·L 1 CO. The average recoveries of CO from the assay system and the sample were 102.1%, RSD=2.9% (n=7) and 79.7%, RSD=6.8% (n=12),respectively. The RSD of within day was 4.4%(n=18),and the RSD of day to day was 6.1%(n=16). By this method, four trihaloanilines and one trihalobenzene were tested, the results showed that only 2,4,5 trifluoroaniline could be converted to CO by the incubation with rat hepatic microsomes, NADPH and oxygen, the ability of phenobarbital or dexamethasone to induce rat hepatic microsomes to catalyze CO formation was 3 or 8 times higher than that of the control.
文摘In the present article, we report the screening-dependent study of the superconducting state parameters （SSPs）, viz. electron-phonon coupling strength A, Coulomb pseudopotential μ^＊, transition temperature TC, isotope effect exponent a, and effective interaction strength No V of 3d-band transition metals binary alloys superconductors have been made extensively in the present work using a model potential formalism and employing the pseudo-alloy-atom （PAA） model for the first time. Five local field correction functions proposed by Hartree （H）, Taylor （T）, Ichimaru-Utsumi （IU）, Farid et al. （F） and Sarkar et al. （S） are used in the present investigation to study the screening influence on the aforesaid properties. The present results of the SSPs obtained from H-screening are found in qualitative agreement with the available experimental data wherever exist.
基金Supported by the National Natural Science Foundation of China under Grant No.10475026the Natural Science Foundation of Zhejiang Province under Grant No.KY607518
文摘Properties of the triaxial superdeformed （TSD） bands of odd-A Lu isotopes are investigated systematically within the supersymmetry scheme including many-body interactions and a perturbation possessing the S0（5） （or SU（5）） symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia and the spin of the TSD bands in odd-A Lu isotopes are obtained. The calculation shows that the competition between the pairing and anti-pairing effects exists in these TSD bands. Meanwhile, the SU（3） symmetry in TSD bands are broken more seriously than in superdeformed （SD） bands.
文摘Through a sampling analysis of trace elements and REE in the section of Middle Permian Zhesi Formation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are characterized by LREE-enrichment. By analysis of the discriminant index of the sedimentary environment,the tectonic setting of Zhesi Formation is determined to be a continental island arc environment. Meanwhile,according to the sedimentary structure and lithology combination,Zhesi Formation is divided into the neritic-bathyal retention-reduction environment as well as the delta front and prodelta sedimentary systems.
基金the National Natural Science Foundation of China (60903111)
文摘A novel algorithm to voxelize 3D mesh models with gray levels is presented in this paper.The key innovation of our method is to decide the gray level of a voxel according to the total area of all surfaces contained by it.During the preprocessing stage,a set of voxels in the extended bounding box of each triangle is established.Then we travel each triangle and compute the areas between it and its set of voxels one by one.Finally,each voxel is arranged a discrete gray level from 0 to 255.Experiments show that our algorithm gets a comparatively perfect result compared with the prevenient ones and approaches the original models in a more accurate way.
