The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the ene...The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the energy source α-S8 or μ-S,respectively.The results of cell growth and sulfur oxidation behavior showed that the strain grown on α-S8 entered slowly(about 1 d later) into the exponential phase,while grew faster in the exponential phase and attained higher maximal cell density and lower p H value than that on μ-S.After bio-corrosion,both of the two sulfur samples were evidently eroded and modified by A.ferrooxidans cells.After growth of A.ferrooxidans,the surface composition of amorphous μ-S became 63.1% μ-S and 36.9% α-S8,and that of orthorhombic α-S8 became 68.3% α-S8 and 31.7% μ-S,while the surface compositions of α-S8 and μ-S in sterile experiment were not changed,indicating that these two elemental sulfur species can be interconverted by A.ferrooxidans.展开更多
Deconvolution denoising in the f-x domain has some defects when facing situations like complicated geology structure, coherent noise of steep dip angles, and uneven spatial sampling. To solve these problems, a new fil...Deconvolution denoising in the f-x domain has some defects when facing situations like complicated geology structure, coherent noise of steep dip angles, and uneven spatial sampling. To solve these problems, a new filtering method is proposed, which uses the generalized S transform which has good time-frequency concentration criterion to transform seismic data from the time-space to time-frequency-space domain (t-f-x). Then in the t-f-x domain apply Empirical Mode Decomposition (EMD) on each frequency slice and clear the Intrinsic Mode Functions (IMFs) that noise dominates to suppress coherent and random noise. The model study shows that the high frequency component in the first IMF represents mainly noise, so clearing the first IMF can suppress noise. The EMD filtering method in the t-f-x domain after generalized S transform is equivalent to self-adaptive f-k filtering that depends on position, frequency, and truncation characteristics of high wave numbers. This filtering method takes local data time-frequency characteristic into consideration and is easy to perform. Compared with AR predictive filtering, the component that this method filters is highly localized and contains relatively fewer low wave numbers and the filter result does not show over-smoothing effects. Real data processing proves that the EMD filtering method in the t-f-x domain after generalized S transform can effectively suppress random and coherent noise of steep dips.展开更多
K-shell ionization for Li-like uranium ions in collisions with a N2 target was performed at the ESR storage ring. We found surprisingly that in such close encounters the 2 s electron remain almost unaffected by the co...K-shell ionization for Li-like uranium ions in collisions with a N2 target was performed at the ESR storage ring. We found surprisingly that in such close encounters the 2 s electron remain almost unaffected by the collisions. A dedicated experimental study was conducted by using Li-like uranium ions at an initial energy of 378 MeV/u in order to manifest the situation. In Fig.1 a typical spectrum is shown registered by a Ge(i)展开更多
In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t - r) dependence of solution in terms of the noncommutative parameter σ....In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t - r) dependence of solution in terms of the noncommutative parameter σ. In this setup, there Js no black hole remnant at long times.展开更多
AIM:To evaluate effects of UDP-glucuronosyltransferase1A1(UGT1A1) and thymidylate synthetase(TS) gene polymorphisms on irinotecan in metastatic colorectal cancer(mCRC).METHODS:Two irinotecan-and fluorouracil-based reg...AIM:To evaluate effects of UDP-glucuronosyltransferase1A1(UGT1A1) and thymidylate synthetase(TS) gene polymorphisms on irinotecan in metastatic colorectal cancer(mCRC).METHODS:Two irinotecan-and fluorouracil-based regimens,FOLFIRI and IFL,were selected as second-line therapy for 138 Chinese mCRC patients.Genomic DNA was extracted from peripheral blood samples before treatment.UGT1A1 and TS gene polymorphisms were determined by direct sequencing and restriction fragment length polymorphism,respectively.Gene polymorphisms of UGT1A1*28,UGT1A1*6 and promoter enhancer region of TS were analyzed.The relationship between genetic polymorphisms and clinical outcome,that is,response,toxicity and survival were assessed.Pharmacokinetic analyses were performed in a subgroup patients based on different UGT1A1 genotypes.Plasma concentration of irinotecan and its active metabolite SN-38 and inactive metabolite SN-38G were determined by high performance liquid chromatography.Differences in irinotecan and its metabolites between UGT1A1 gene variants were compared.RESULTS:One hundred and eight patients received the FOLFIRI regimen,29 the IFL regimen,and one irinotecan monotherapy.One hundred and thirty patients were eligible for toxicity and 111 for efficacy evaluation.One hundred and thirty-six patients were tested for UGT1A1*28 and *6 genotypes and 125 for promoter enhancer region of TS.Patients showed a higher frequency of wild-type UGT1A1*28(TA6/6) compared with a Caucasian population(69.9% vs 45.2%).No significant difference was found between response rates and UGT1A1 genotype,although wild-type showed lower response rates compared with other variants(17.9% vs 24.2% for UGT1A1*28,15.7% vs 26.8% for UGT1A1*6).When TS was considered,the subgroup with homozygous UGT1A1*28(TA7/7) and non-3RG genotypes showed the highest response rate(33.3%),while wild-type UGT1A1*28(TA6/6) with non-3RG only had a 13.6% response rate,but no significant difference was found.Logistic regression showed treatment duration was closely linked to clinical response.In toxicity comparison,UGT1A1*28 TA6/6 was associated with lower incidence of grade 2-4 diarrhea(27.8% vs 100%),and significantly reduced the risk of grade 4 neutropenia compared with TA7/7(7.8% vs 37.5%).Wild-type UGT1A1*6(G/G) tended to have a lower incidence of grade 3/4 diarrhea vs homozygous mutant(A/A) genotype(13.0% vs 40.0%).Taking UGT1A1 and TS genotypes together,lower incidence of grade 2-4 diarrhea was found in patients with non-3RG TS genotypes,when TA6/6 was compared with TA7/7(35.3% vs 100.0%).No significant association with time to progression(TTP) and overall survival(OS) was observed with either UGT1A1 or TS gene polymorphisms,although slightly longer TTP and OS were found with UGT1A1*28(TA6/6).Irinotecan PK was investigated in 34 patients,which showed high area under concentration curve(AUC) of irinotecan and SN-38,but low AUC ratio(SN-38G /SN-38) in those patients with UGT1A1*28 TA7/7.CONCLUSION:A distinct distribution pattern of UGT1A1 genotypes in Chinese patients might contribute to relatively low toxicity associated with irinotecan and 5-fluorouracil in mCRC patients.展开更多
AIM: To investigate the glutathione-S-transferase M1 (GSTM1) polymorphisms in three Chinese minorities, Kazakh, Uygur, and Tajik; and the pathological significance of GSTM1 polymorphisms in esophageal carcinogenesi...AIM: To investigate the glutathione-S-transferase M1 (GSTM1) polymorphisms in three Chinese minorities, Kazakh, Uygur, and Tajik; and the pathological significance of GSTM1 polymorphisms in esophageal carcinogenesis in Kazakh.METHODS: A total of 1121 blood samples (442 males and 679 females) were obtained from healthy Kazakh (654), Uygur (412) and Tajik (55). Primary esophageal squamous cell cancer (ESCC) tissues from Kazakh were obtained from 116 patients who underwent surgery. GSTM1 polymorphisms were analyzed by a combined approach of PCR and electrophoresis techniques.RESULTS: GSTM1 null genotype was found in 62.63% Uygur, 50.91% Tajik and 47.40% Kazakh. A significantly higher frequency of GSTM1 null genotype in Uygur was observed compared with Kazakh (OR: 1.859, 95% CI: 1.445 -2.391, χ^2 = 23.71, P = 0.000). In addition, GSTM1 null genotype was found in 23.53% of welldifferentiated ESCC in Kazakh, in 49.23% of poorly differentiated ESCC, with a significant difference (OR: 3.152, 95% CI: 1.403-7.080, χ^2 = 8.018, P = 0.007).CONCLUSION: There is a marked difference in the frequency of common GSTM1 null genotype between Uygur and Kazakh. GSTM1 null genotype is associated with differentiation of ESCC in Kazakh.展开更多
AIM: To investigate the colorectal cancer risk associated with polymorphic GSTM1, GSTT1 and GSTP1 and the effect of diet and smoking.METHODS: With consents, genotypes of the genes were determined using PCR methods for...AIM: To investigate the colorectal cancer risk associated with polymorphic GSTM1, GSTT1 and GSTP1 and the effect of diet and smoking.METHODS: With consents, genotypes of the genes were determined using PCR methods for 727 cases and 736sex and age-matched healthy controls recruited at a medical center in the Northern Taiwan. Nurses who were blind to the study hypothesis conducted interviews with study participants for the information of socio-demographic variables, diet and smoking.RESULTS: There was no significant association between GSTM1 genotypes and the disease. Men, not women, with GSTT1 null genotype were at significant risk of colorectal cancer, but limited to rectal tumor, and in men aged 60 years and less. The corresponding association with the GSTP1 with G allele compared to GSTP1 A/A genotype was at borderline significance. Compared to men with GSTT1 present and GSTP1 A/A combined, men with both GSTT1 null and GSTP1 with G allele genotypes were at significant risk (odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.21-3.02), also limited to the rectal tumor and younger men. The beneficial effects of vegetable/fruit intake on colorectal cancer were much higher for men with GSTT1 present (OR = 0.32, 95%CI = 0.20-0.50) or GSTP1 A/A genotypes (OR = 0.40, 95%CI = 0.25-0.64).These effects remained significant for women. But, the greatest protective effect from vegetable/fruit intake for women was observed in those with GSTT1 null or GSTP1 with G allele genotypes. In addition, non-smoking men benefitted significantly from combined effect of higher vegetable/fruit intake and GSTT1 present or GSTP1 A/A genotypes with OR = 0.17 and 0.21 respectively.CONCLUSION: This study suggests that the GSTT1 gene can modulate the colorectal cancer risk and vegetable/fruit-related colorectal cancer risk, particularly in men of no smoking history.展开更多
Bismuth selenide(Bi_(2)Se_(3))is an attractive visible-light-responsive semiconductor that can absorb a full range of visible and near-infrared light.However,its poor redox capacity and rapid carrier recombination lim...Bismuth selenide(Bi_(2)Se_(3))is an attractive visible-light-responsive semiconductor that can absorb a full range of visible and near-infrared light.However,its poor redox capacity and rapid carrier recombination limit its application in photocatalytic oxidation.In this study,we adopted Bi_(2)Se_(3)as the couple part of graphitic carbon nitride(g-C_(3)N_(4))to construct a Bi_(2)Se_(3)/g-C_(3)N_(4)composite photocatalyst.Through in situ fabrication,the self-developed Bi2O3/g-C_(3)N_(4)precursor was transformed into a Bi_(2)Se_(3)/g-C_(3)N_(4)heterojunction.The as-prepared Bi_(2)Se_(3)/g-C_(3)N_(4)composite exhibited much higher visible-light-driven photocatalytic activity than pristine Bi_(2)Se_(3)and g-C_(3)N_(4)in the removal of phenol.The enhanced photocatalytic activity was ascribed to the S-scheme configuration of Bi_(2)Se_(3)/g-C_(3)N_(4);this was confirmed by the energy-level shift,photoluminescence analysis,computational structure study,and reactive-radical testing.In the S-scheme heterojunction,photo-excited electrons in the conduction band of g-C_(3)N_(4)migrate to the valence band of Bi_(2)Se_(3)and combine with the excited holes therein.By consuming less reactive carriers,the S-scheme heterojunction can not only effectively promote charge separation,but also preserve more reactive photo-generated carriers.This property enhances the photocatalytic activity.展开更多
Based on the theory of polymorphic virtual S-box, the paper presents a symmetric key exchange protocol to solve the problem of session keys delete shared in the computational complexity temporary trading scenario. Bot...Based on the theory of polymorphic virtual S-box, the paper presents a symmetric key exchange protocol to solve the problem of session keys delete shared in the computational complexity temporary trading scenario. Both parties jointly construct a highly nonlinear SPN core algorithm. The paper the connotation of polymorphic cipher theory, making use of the method of self-compiler based expansion factor to collect random parameter sets held by each of the parties containing its own information 5-tuple private keys array Kpa[5] and Kpb[5].The more efficient polymorphism virtual S-box is constructed. The method of secret split for the public key cryptography features can be implemented by symmetry cipher system. The research results will provide a theoretical basis to solve the key exchange problems for short- term communications partner based on symmetric cryptography.展开更多
AIM: Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genes are involved in the metabolism of a wide range of carcinogens, but deletions of the genes are commonly found in the population. The present study w...AIM: Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genes are involved in the metabolism of a wide range of carcinogens, but deletions of the genes are commonly found in the population. The present study was undertaken to evaluate the association between GSTM1 and GSTT1 gene polymorphisms and hepatocellular carcinoma (HCC) risk. METHODS: The genetic polymorphisms were studied at an aflatoxin highly contaminated region in Guangxi, China. Pdymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in blood samples. The case group was composed of 181 patients of HCC identified by the pathologists and the control group was composed of 360 adults without any tumor. RESULTS: The frequencies of GSTM1 and GSTT1 null genotypes in the control were 47.8% and 42.7%, while those in the HCC group were 64.6% and 59.7%, respectively. The differences between HCC group and control group were very significant (P<0.01). GSTM1 and GSTT1 combined null genotypes in HCC group and control group were 38.2% and 18.5% respectively, and the difference was significant (P<0.05). CONCLUSION: The GSTM1 and GSTT1 null genotypes are associated with an increased risk of HCC in a special geographic environment. Combination of the two null genotypes in an individual is substantially increased twice the risk of HCC.展开更多
Objective:The aim of our study was to investigate the distribution of glutathione-S-transferase M1 (GSTM1) and T1 (GSTT1) gene polymorphism in hepatocellular carcinoma (HCC) and nasopharyngeal carcinoma (NPC) patients...Objective:The aim of our study was to investigate the distribution of glutathione-S-transferase M1 (GSTM1) and T1 (GSTT1) gene polymorphism in hepatocellular carcinoma (HCC) and nasopharyngeal carcinoma (NPC) patients in a high risk area in Guangxi Zhuang Autonomous Region,China.Methods:It was a case-control study.The genotypes of GSTM1 and GSTT1 in 181 HCC and 126 NPC patients were compared with 641 matched control.The GSTM1 and GSTT1 genotypes were detected using conventional multiplex PCR method.Results:The frequency of GSTM1 null genotype in HCC,NPC and control groups were 65.2%,61.9% and 47.6% respectively,significant difference between these two cancer groups and control was observed (P < 0.01).The frequency of GSTT1 null genotype in HCC,NPC and control groups were 57.5%,62.7% and 43.1% respectively,significant difference between these two cancer groups and control was observed (P < 0.01).Conclusion:The distributions of GSTM1 and T1 genes are polymorphic in HCC and NPC patients in a high risk area in Guangxi,individuals with GSTM1-null or GSTT1-null would have an increasing risk of developing HCC and NPC,especially when combination with virus infection (HBV or EBV) and absorbed chemical toxin (AFB1 or cigarette).展开更多
A hybrid of ensemble empirical mode decomposition and empirical mode decomposition (EEMD-EMD) is introduced to diagnose the valve-slap vibration signal,which is relative to the dominant combustion knock vibration sign...A hybrid of ensemble empirical mode decomposition and empirical mode decomposition (EEMD-EMD) is introduced to diagnose the valve-slap vibration signal,which is relative to the dominant combustion knock vibration signal given out by a diesel engine around the top dead center (TDC).The time-frequency representations of intrinsic mode functions (IMFs) decomposed by EEMD-EMD are obtained by adaptive generalized S transform (AGST).A type 493 diesel engine was used for the experiment,and the result indicates that the valve-slap of the diesel engine is serious,and the vibration frequencies are higher than the combustion knock.With EEMD-EMD-AGST approach,the valve-slap can be identified by the vibration analysis of the diesel engine.展开更多
The work was carried out to study the uptake, storage and return of S in the evergreen broad-leaved forestecosystem of Hangzhou in Zhejiang Province, China, based on the annual increments of plants and S contentsper u...The work was carried out to study the uptake, storage and return of S in the evergreen broad-leaved forestecosystem of Hangzhou in Zhejiang Province, China, based on the annual increments of plants and S contentsper unit weight plant organs as well as the measured data about the biological return and decomposition.Results showed that the vegetation layer had an annual S uptake of 55.02kg ha ̄(-1) , which accounted for 15.8% of the total S storage in the vegetation layer. The S uptake was the highest in the arbor layer but thelowest in the shrub layer. The biological return of S was 50% higher than the biological uptake, indicatingthe relatively high cycling efficiency of S. Nevertheless, S had a relatively low rate of biological release, so thatS trended to accumulate in the litter layer. S taken up by plants each year came mostly from precipitationand the reserve of soil.展开更多
基金Project(51274257)supported by the National Natural Science Foundation of ChinaProject(U1232103)supported by the Joint Funds of National Natural Science Foundation of China and Large Scientific Facility Foundation of Chinese Academy of SciencesProject(VR-12419)supported by the Beijing Synchrotron Radiation Facility Public User Program
文摘The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the energy source α-S8 or μ-S,respectively.The results of cell growth and sulfur oxidation behavior showed that the strain grown on α-S8 entered slowly(about 1 d later) into the exponential phase,while grew faster in the exponential phase and attained higher maximal cell density and lower p H value than that on μ-S.After bio-corrosion,both of the two sulfur samples were evidently eroded and modified by A.ferrooxidans cells.After growth of A.ferrooxidans,the surface composition of amorphous μ-S became 63.1% μ-S and 36.9% α-S8,and that of orthorhombic α-S8 became 68.3% α-S8 and 31.7% μ-S,while the surface compositions of α-S8 and μ-S in sterile experiment were not changed,indicating that these two elemental sulfur species can be interconverted by A.ferrooxidans.
基金sponsored by the National Natural Science Foundation of China (Grant No. 41174114)the National Natural Science Foundation of China and China Petroleum & Chemical Corporation Co-funded Project (No. 40839905)
文摘Deconvolution denoising in the f-x domain has some defects when facing situations like complicated geology structure, coherent noise of steep dip angles, and uneven spatial sampling. To solve these problems, a new filtering method is proposed, which uses the generalized S transform which has good time-frequency concentration criterion to transform seismic data from the time-space to time-frequency-space domain (t-f-x). Then in the t-f-x domain apply Empirical Mode Decomposition (EMD) on each frequency slice and clear the Intrinsic Mode Functions (IMFs) that noise dominates to suppress coherent and random noise. The model study shows that the high frequency component in the first IMF represents mainly noise, so clearing the first IMF can suppress noise. The EMD filtering method in the t-f-x domain after generalized S transform is equivalent to self-adaptive f-k filtering that depends on position, frequency, and truncation characteristics of high wave numbers. This filtering method takes local data time-frequency characteristic into consideration and is easy to perform. Compared with AR predictive filtering, the component that this method filters is highly localized and contains relatively fewer low wave numbers and the filter result does not show over-smoothing effects. Real data processing proves that the EMD filtering method in the t-f-x domain after generalized S transform can effectively suppress random and coherent noise of steep dips.
文摘K-shell ionization for Li-like uranium ions in collisions with a N2 target was performed at the ESR storage ring. We found surprisingly that in such close encounters the 2 s electron remain almost unaffected by the collisions. A dedicated experimental study was conducted by using Li-like uranium ions at an initial energy of 378 MeV/u in order to manifest the situation. In Fig.1 a typical spectrum is shown registered by a Ge(i)
文摘In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t - r) dependence of solution in terms of the noncommutative parameter σ. In this setup, there Js no black hole remnant at long times.
基金Supported by National Natural Science Foundation Project, No.30971579the Capital Medical Development Foundation, No.2007-2029
文摘AIM:To evaluate effects of UDP-glucuronosyltransferase1A1(UGT1A1) and thymidylate synthetase(TS) gene polymorphisms on irinotecan in metastatic colorectal cancer(mCRC).METHODS:Two irinotecan-and fluorouracil-based regimens,FOLFIRI and IFL,were selected as second-line therapy for 138 Chinese mCRC patients.Genomic DNA was extracted from peripheral blood samples before treatment.UGT1A1 and TS gene polymorphisms were determined by direct sequencing and restriction fragment length polymorphism,respectively.Gene polymorphisms of UGT1A1*28,UGT1A1*6 and promoter enhancer region of TS were analyzed.The relationship between genetic polymorphisms and clinical outcome,that is,response,toxicity and survival were assessed.Pharmacokinetic analyses were performed in a subgroup patients based on different UGT1A1 genotypes.Plasma concentration of irinotecan and its active metabolite SN-38 and inactive metabolite SN-38G were determined by high performance liquid chromatography.Differences in irinotecan and its metabolites between UGT1A1 gene variants were compared.RESULTS:One hundred and eight patients received the FOLFIRI regimen,29 the IFL regimen,and one irinotecan monotherapy.One hundred and thirty patients were eligible for toxicity and 111 for efficacy evaluation.One hundred and thirty-six patients were tested for UGT1A1*28 and *6 genotypes and 125 for promoter enhancer region of TS.Patients showed a higher frequency of wild-type UGT1A1*28(TA6/6) compared with a Caucasian population(69.9% vs 45.2%).No significant difference was found between response rates and UGT1A1 genotype,although wild-type showed lower response rates compared with other variants(17.9% vs 24.2% for UGT1A1*28,15.7% vs 26.8% for UGT1A1*6).When TS was considered,the subgroup with homozygous UGT1A1*28(TA7/7) and non-3RG genotypes showed the highest response rate(33.3%),while wild-type UGT1A1*28(TA6/6) with non-3RG only had a 13.6% response rate,but no significant difference was found.Logistic regression showed treatment duration was closely linked to clinical response.In toxicity comparison,UGT1A1*28 TA6/6 was associated with lower incidence of grade 2-4 diarrhea(27.8% vs 100%),and significantly reduced the risk of grade 4 neutropenia compared with TA7/7(7.8% vs 37.5%).Wild-type UGT1A1*6(G/G) tended to have a lower incidence of grade 3/4 diarrhea vs homozygous mutant(A/A) genotype(13.0% vs 40.0%).Taking UGT1A1 and TS genotypes together,lower incidence of grade 2-4 diarrhea was found in patients with non-3RG TS genotypes,when TA6/6 was compared with TA7/7(35.3% vs 100.0%).No significant association with time to progression(TTP) and overall survival(OS) was observed with either UGT1A1 or TS gene polymorphisms,although slightly longer TTP and OS were found with UGT1A1*28(TA6/6).Irinotecan PK was investigated in 34 patients,which showed high area under concentration curve(AUC) of irinotecan and SN-38,but low AUC ratio(SN-38G /SN-38) in those patients with UGT1A1*28 TA7/7.CONCLUSION:A distinct distribution pattern of UGT1A1 genotypes in Chinese patients might contribute to relatively low toxicity associated with irinotecan and 5-fluorouracil in mCRC patients.
基金Supported by a grant from the Xinjiang Science and TechnologyBureau, No. XJKJT200511113 and a grant for 100 YoungExcellent Returned Overseas Chinese Scholars Program, ChineseAcademy of Sciences
文摘AIM: To investigate the glutathione-S-transferase M1 (GSTM1) polymorphisms in three Chinese minorities, Kazakh, Uygur, and Tajik; and the pathological significance of GSTM1 polymorphisms in esophageal carcinogenesis in Kazakh.METHODS: A total of 1121 blood samples (442 males and 679 females) were obtained from healthy Kazakh (654), Uygur (412) and Tajik (55). Primary esophageal squamous cell cancer (ESCC) tissues from Kazakh were obtained from 116 patients who underwent surgery. GSTM1 polymorphisms were analyzed by a combined approach of PCR and electrophoresis techniques.RESULTS: GSTM1 null genotype was found in 62.63% Uygur, 50.91% Tajik and 47.40% Kazakh. A significantly higher frequency of GSTM1 null genotype in Uygur was observed compared with Kazakh (OR: 1.859, 95% CI: 1.445 -2.391, χ^2 = 23.71, P = 0.000). In addition, GSTM1 null genotype was found in 23.53% of welldifferentiated ESCC in Kazakh, in 49.23% of poorly differentiated ESCC, with a significant difference (OR: 3.152, 95% CI: 1.403-7.080, χ^2 = 8.018, P = 0.007).CONCLUSION: There is a marked difference in the frequency of common GSTM1 null genotype between Uygur and Kazakh. GSTM1 null genotype is associated with differentiation of ESCC in Kazakh.
基金Supported by National Science Council No. 89-2314-B-002-373,90-2320-B-002-123 and 91-2320-B-002-121National Health Research Institute No. 85-HR-516, 86-HR-516, and 87-HR-516
文摘AIM: To investigate the colorectal cancer risk associated with polymorphic GSTM1, GSTT1 and GSTP1 and the effect of diet and smoking.METHODS: With consents, genotypes of the genes were determined using PCR methods for 727 cases and 736sex and age-matched healthy controls recruited at a medical center in the Northern Taiwan. Nurses who were blind to the study hypothesis conducted interviews with study participants for the information of socio-demographic variables, diet and smoking.RESULTS: There was no significant association between GSTM1 genotypes and the disease. Men, not women, with GSTT1 null genotype were at significant risk of colorectal cancer, but limited to rectal tumor, and in men aged 60 years and less. The corresponding association with the GSTP1 with G allele compared to GSTP1 A/A genotype was at borderline significance. Compared to men with GSTT1 present and GSTP1 A/A combined, men with both GSTT1 null and GSTP1 with G allele genotypes were at significant risk (odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.21-3.02), also limited to the rectal tumor and younger men. The beneficial effects of vegetable/fruit intake on colorectal cancer were much higher for men with GSTT1 present (OR = 0.32, 95%CI = 0.20-0.50) or GSTP1 A/A genotypes (OR = 0.40, 95%CI = 0.25-0.64).These effects remained significant for women. But, the greatest protective effect from vegetable/fruit intake for women was observed in those with GSTT1 null or GSTP1 with G allele genotypes. In addition, non-smoking men benefitted significantly from combined effect of higher vegetable/fruit intake and GSTT1 present or GSTP1 A/A genotypes with OR = 0.17 and 0.21 respectively.CONCLUSION: This study suggests that the GSTT1 gene can modulate the colorectal cancer risk and vegetable/fruit-related colorectal cancer risk, particularly in men of no smoking history.
文摘Bismuth selenide(Bi_(2)Se_(3))is an attractive visible-light-responsive semiconductor that can absorb a full range of visible and near-infrared light.However,its poor redox capacity and rapid carrier recombination limit its application in photocatalytic oxidation.In this study,we adopted Bi_(2)Se_(3)as the couple part of graphitic carbon nitride(g-C_(3)N_(4))to construct a Bi_(2)Se_(3)/g-C_(3)N_(4)composite photocatalyst.Through in situ fabrication,the self-developed Bi2O3/g-C_(3)N_(4)precursor was transformed into a Bi_(2)Se_(3)/g-C_(3)N_(4)heterojunction.The as-prepared Bi_(2)Se_(3)/g-C_(3)N_(4)composite exhibited much higher visible-light-driven photocatalytic activity than pristine Bi_(2)Se_(3)and g-C_(3)N_(4)in the removal of phenol.The enhanced photocatalytic activity was ascribed to the S-scheme configuration of Bi_(2)Se_(3)/g-C_(3)N_(4);this was confirmed by the energy-level shift,photoluminescence analysis,computational structure study,and reactive-radical testing.In the S-scheme heterojunction,photo-excited electrons in the conduction band of g-C_(3)N_(4)migrate to the valence band of Bi_(2)Se_(3)and combine with the excited holes therein.By consuming less reactive carriers,the S-scheme heterojunction can not only effectively promote charge separation,but also preserve more reactive photo-generated carriers.This property enhances the photocatalytic activity.
基金the National Natural Science Foundation of China under Grant No.61272038 and No.61340059,Zhengzhou Academician Workstation Funded Projects,the Education Department of Henan Province Science and Technology Research Project,Key Project of Science and Technology Research,the Doctor Fund of Zhengzhou University of Light Industry
文摘Based on the theory of polymorphic virtual S-box, the paper presents a symmetric key exchange protocol to solve the problem of session keys delete shared in the computational complexity temporary trading scenario. Both parties jointly construct a highly nonlinear SPN core algorithm. The paper the connotation of polymorphic cipher theory, making use of the method of self-compiler based expansion factor to collect random parameter sets held by each of the parties containing its own information 5-tuple private keys array Kpa[5] and Kpb[5].The more efficient polymorphism virtual S-box is constructed. The method of secret split for the public key cryptography features can be implemented by symmetry cipher system. The research results will provide a theoretical basis to solve the key exchange problems for short- term communications partner based on symmetric cryptography.
基金Supported by The Natural Scientific Foundation of China No. 39860032by the Education Department of Guangxi Zhuang Autonomous Region No. 98-2-8
文摘AIM: Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genes are involved in the metabolism of a wide range of carcinogens, but deletions of the genes are commonly found in the population. The present study was undertaken to evaluate the association between GSTM1 and GSTT1 gene polymorphisms and hepatocellular carcinoma (HCC) risk. METHODS: The genetic polymorphisms were studied at an aflatoxin highly contaminated region in Guangxi, China. Pdymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in blood samples. The case group was composed of 181 patients of HCC identified by the pathologists and the control group was composed of 360 adults without any tumor. RESULTS: The frequencies of GSTM1 and GSTT1 null genotypes in the control were 47.8% and 42.7%, while those in the HCC group were 64.6% and 59.7%, respectively. The differences between HCC group and control group were very significant (P<0.01). GSTM1 and GSTT1 combined null genotypes in HCC group and control group were 38.2% and 18.5% respectively, and the difference was significant (P<0.05). CONCLUSION: The GSTM1 and GSTT1 null genotypes are associated with an increased risk of HCC in a special geographic environment. Combination of the two null genotypes in an individual is substantially increased twice the risk of HCC.
基金Supported by agrant from the National Natural Sciences Foundation of China (No. 39860032)
文摘Objective:The aim of our study was to investigate the distribution of glutathione-S-transferase M1 (GSTM1) and T1 (GSTT1) gene polymorphism in hepatocellular carcinoma (HCC) and nasopharyngeal carcinoma (NPC) patients in a high risk area in Guangxi Zhuang Autonomous Region,China.Methods:It was a case-control study.The genotypes of GSTM1 and GSTT1 in 181 HCC and 126 NPC patients were compared with 641 matched control.The GSTM1 and GSTT1 genotypes were detected using conventional multiplex PCR method.Results:The frequency of GSTM1 null genotype in HCC,NPC and control groups were 65.2%,61.9% and 47.6% respectively,significant difference between these two cancer groups and control was observed (P < 0.01).The frequency of GSTT1 null genotype in HCC,NPC and control groups were 57.5%,62.7% and 43.1% respectively,significant difference between these two cancer groups and control was observed (P < 0.01).Conclusion:The distributions of GSTM1 and T1 genes are polymorphic in HCC and NPC patients in a high risk area in Guangxi,individuals with GSTM1-null or GSTT1-null would have an increasing risk of developing HCC and NPC,especially when combination with virus infection (HBV or EBV) and absorbed chemical toxin (AFB1 or cigarette).
基金Supported by National Key Technology Research and Development Program of China (No.2011BAE22B05)
文摘A hybrid of ensemble empirical mode decomposition and empirical mode decomposition (EEMD-EMD) is introduced to diagnose the valve-slap vibration signal,which is relative to the dominant combustion knock vibration signal given out by a diesel engine around the top dead center (TDC).The time-frequency representations of intrinsic mode functions (IMFs) decomposed by EEMD-EMD are obtained by adaptive generalized S transform (AGST).A type 493 diesel engine was used for the experiment,and the result indicates that the valve-slap of the diesel engine is serious,and the vibration frequencies are higher than the combustion knock.With EEMD-EMD-AGST approach,the valve-slap can be identified by the vibration analysis of the diesel engine.
文摘The work was carried out to study the uptake, storage and return of S in the evergreen broad-leaved forestecosystem of Hangzhou in Zhejiang Province, China, based on the annual increments of plants and S contentsper unit weight plant organs as well as the measured data about the biological return and decomposition.Results showed that the vegetation layer had an annual S uptake of 55.02kg ha ̄(-1) , which accounted for 15.8% of the total S storage in the vegetation layer. The S uptake was the highest in the arbor layer but thelowest in the shrub layer. The biological return of S was 50% higher than the biological uptake, indicatingthe relatively high cycling efficiency of S. Nevertheless, S had a relatively low rate of biological release, so thatS trended to accumulate in the litter layer. S taken up by plants each year came mostly from precipitationand the reserve of soil.