AIM:To evaluate the association between p53 codon 72 polymorphism and liver cancer risk by means of meta-analysis. METHODS:Two investigators independently searched the Medline,Embase and Chinese Biomedicine databases....AIM:To evaluate the association between p53 codon 72 polymorphism and liver cancer risk by means of meta-analysis. METHODS:Two investigators independently searched the Medline,Embase and Chinese Biomedicine databases.Summary odds ratios and 95%CI for p53 codon 72 polymorphism and liver cancer were calculated in fixedeffects model(Mantel-Haenszel method)and randomeffects model(DerSimonian and Laird method)when appropriate. RESULTS:This meta-analysis included 1115 liver cancer cases and 1778 controls.The combined results based on all studies showed that there was a statistically significant link between Pro/Pro genotype and liver cancer,but not between Arg/Arg or Pro/Arg genotype and liver cancer.When stratifying for race,similar results were obtained,i.e.patients with liver cancer had a significantly higher frequency of Pro/Pro genotype than non-cancer patients among Asians.After stratifying thevarious studies by control source,gender,family history of liver cancer and chronic hepatitis virus infection,we found that(1)patients among hospital-based studies had a significantly higher frequency of Pro/Pro and a significantly lower frequency of Arg/Arg genotype than individuals without cancer;(2)female patients with liver cancer had a significantly lower frequency of Arg/Arg and a higher frequency of Pro/Arg+Pro/Pro genotypes than female individuals without cancer;(3)subgroup analyses for family history of liver cancer did not reveal any significant association between p53 codon 72 polymorphism and liver cancer development;and(4) patients with negative hepatitis virus infection had a significantly higher frequency of Pro/Pro and a significantly lower frequency of Arg/Arg genotype than individuals without cancer. CONCLUSION:This meta-analysis suggests that the p53 codon 72 polymorphism may be associated with liver cancer among Asians.展开更多
A novel subtype of influenza A virus 09H1N1 has rapidly spread across the world. Evolutionary analyses of this virus have revealed that 09H1N1 is a triple reassortant of segments from swine, avian and human influenza ...A novel subtype of influenza A virus 09H1N1 has rapidly spread across the world. Evolutionary analyses of this virus have revealed that 09H1N1 is a triple reassortant of segments from swine, avian and human influenza viruses. In this study, we investigated factors shaping the codon usage bias of 09H1N1 and carried out cluster analysis of 60 strains of influenza A virus from different subtypes based on their codon usage bias. We discovered that more preferentially used codons of 09H1N1 are A-ended or U-ended, and the intra-genomic codon usage bias of 09H1N1 is quite low. Base composition constraint, dinucleotide biases and translational selection are the main factors influencing the codon usage bias of 09H1N1. At the genome level, we find that the codon usage bias of 09H1N1 is similar to H1N1 (A/swine/Kansas/77778/2007H1N1), H9N2 from Asia, H1N2 from Asia and North America and H3N2 from North America. Our results provide insight for understanding the processes governing evolution, regulation of gene expression, and revealing the evolution of 09H1N1.展开更多
Permeability is a vital property of rock mass, which is highly affected by tectonic stress and human engineering activities. A comprehensive monitoring of pore pressure and flow rate distributions inside the rock mass...Permeability is a vital property of rock mass, which is highly affected by tectonic stress and human engineering activities. A comprehensive monitoring of pore pressure and flow rate distributions inside the rock mass is very important to elucidate the permeability evolution mechanisms, which is difficult to realize in laboratory, but easy to be achieved in numerical simulations. Therefore, the particle flow code (PFC), a discrete element method, is used to simulate permeability behaviors of rock materials in this study. Owe to the limitation of the existed solid-fluid coupling algorithm in PFC, an improved flow-coupling algorithm is presented to better reflect the preferential flow in rock fractures. The comparative analysis is conducted between original and improved algorithm when simulating rock permeability evolution during triaxial compression, showing that the improved algorithm can better describe the experimental phenomenon. Furthermore, the evolution of pore pressure and flow rate distribution during the flow process are analyzed by using the improved algorithm. It is concluded that during the steady flow process in the fractured specimen, the pore pressure and flow rate both prefer transmitting through the fractures rather than rock matrix. Based on the results, fractures are divided into the following three types: I) fractures link to both the inlet and outlet, II) fractures only link to the inlet, and III) fractures only link to the outlet. The type I fracture is always the preferential propagating path for both the pore pressure and flow rate. For type II fractures, the pore pressure increases and then becomes steady. However, the flow rate increases first and begins to decrease after the flow reaches the stop end of the fracture and finally vanishes. There is no obvious pore pressure or flow rate concentration within type III fractures.展开更多
Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in...Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3' end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.展开更多
This paper proposes Steepest Decreasing Constant Modulus Algorithm (SDCMA) detection in frequency dornain for MultiCarrier Direct Sequence-Code Division Multiple Access (MC DS-CDMA) systems. The proposed algorithm...This paper proposes Steepest Decreasing Constant Modulus Algorithm (SDCMA) detection in frequency dornain for MultiCarrier Direct Sequence-Code Division Multiple Access (MC DS-CDMA) systems. The proposed algorithm is used to equalize independent ladings of all subcarriers. At the same time we compare the SDCMA blind detection with subspace-based Minimum Mean-Squared Error (MMSE) detection. The simulation results show that the pertbrmance of SDCMA blind detection is superior to that of subspace-based MMSE detection and the complexity of the former is much lower than that of the latter.展开更多
An effective method for eddy current calculation has been developed for EAST’s new divertor by using ANSYS.A 3D model of a double null divertor for the EAST device was built to evaluate eddy currents and electromagne...An effective method for eddy current calculation has been developed for EAST’s new divertor by using ANSYS.A 3D model of a double null divertor for the EAST device was built to evaluate eddy currents and electromagnetic(EM)forces on these components.The main input to the model is the plasma current and poloidal field coil currents,which are loaded into the model using experimental data measured from the EAST discharges.These currents generate magnetic fields that match those producing an EAST discharge,and the time variation of these fields produces the eddy currents in the divertors,along with from the resulting EM forces.In addition,the first 10 time steps were discussed for the eddy current generation and changing trend.It indicates that a static analysis before a transient mode start can solve the eddy current origination in the initial time steps.With this method,the EM transient response of EAST’s new divertor can be predicted based on ANSYS simulations.Furthermore,the method is also an effective approach to estimate the EM results for the in-vessel components of a fusion reactor during a disruption.展开更多
文摘AIM:To evaluate the association between p53 codon 72 polymorphism and liver cancer risk by means of meta-analysis. METHODS:Two investigators independently searched the Medline,Embase and Chinese Biomedicine databases.Summary odds ratios and 95%CI for p53 codon 72 polymorphism and liver cancer were calculated in fixedeffects model(Mantel-Haenszel method)and randomeffects model(DerSimonian and Laird method)when appropriate. RESULTS:This meta-analysis included 1115 liver cancer cases and 1778 controls.The combined results based on all studies showed that there was a statistically significant link between Pro/Pro genotype and liver cancer,but not between Arg/Arg or Pro/Arg genotype and liver cancer.When stratifying for race,similar results were obtained,i.e.patients with liver cancer had a significantly higher frequency of Pro/Pro genotype than non-cancer patients among Asians.After stratifying thevarious studies by control source,gender,family history of liver cancer and chronic hepatitis virus infection,we found that(1)patients among hospital-based studies had a significantly higher frequency of Pro/Pro and a significantly lower frequency of Arg/Arg genotype than individuals without cancer;(2)female patients with liver cancer had a significantly lower frequency of Arg/Arg and a higher frequency of Pro/Arg+Pro/Pro genotypes than female individuals without cancer;(3)subgroup analyses for family history of liver cancer did not reveal any significant association between p53 codon 72 polymorphism and liver cancer development;and(4) patients with negative hepatitis virus infection had a significantly higher frequency of Pro/Pro and a significantly lower frequency of Arg/Arg genotype than individuals without cancer. CONCLUSION:This meta-analysis suggests that the p53 codon 72 polymorphism may be associated with liver cancer among Asians.
文摘A novel subtype of influenza A virus 09H1N1 has rapidly spread across the world. Evolutionary analyses of this virus have revealed that 09H1N1 is a triple reassortant of segments from swine, avian and human influenza viruses. In this study, we investigated factors shaping the codon usage bias of 09H1N1 and carried out cluster analysis of 60 strains of influenza A virus from different subtypes based on their codon usage bias. We discovered that more preferentially used codons of 09H1N1 are A-ended or U-ended, and the intra-genomic codon usage bias of 09H1N1 is quite low. Base composition constraint, dinucleotide biases and translational selection are the main factors influencing the codon usage bias of 09H1N1. At the genome level, we find that the codon usage bias of 09H1N1 is similar to H1N1 (A/swine/Kansas/77778/2007H1N1), H9N2 from Asia, H1N2 from Asia and North America and H3N2 from North America. Our results provide insight for understanding the processes governing evolution, regulation of gene expression, and revealing the evolution of 09H1N1.
基金Project(BK20150005) supported by the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars, China Project(2015XKZD05) supported by the Fundamental Research Funds for the Central Universities, China
文摘Permeability is a vital property of rock mass, which is highly affected by tectonic stress and human engineering activities. A comprehensive monitoring of pore pressure and flow rate distributions inside the rock mass is very important to elucidate the permeability evolution mechanisms, which is difficult to realize in laboratory, but easy to be achieved in numerical simulations. Therefore, the particle flow code (PFC), a discrete element method, is used to simulate permeability behaviors of rock materials in this study. Owe to the limitation of the existed solid-fluid coupling algorithm in PFC, an improved flow-coupling algorithm is presented to better reflect the preferential flow in rock fractures. The comparative analysis is conducted between original and improved algorithm when simulating rock permeability evolution during triaxial compression, showing that the improved algorithm can better describe the experimental phenomenon. Furthermore, the evolution of pore pressure and flow rate distribution during the flow process are analyzed by using the improved algorithm. It is concluded that during the steady flow process in the fractured specimen, the pore pressure and flow rate both prefer transmitting through the fractures rather than rock matrix. Based on the results, fractures are divided into the following three types: I) fractures link to both the inlet and outlet, II) fractures only link to the inlet, and III) fractures only link to the outlet. The type I fracture is always the preferential propagating path for both the pore pressure and flow rate. For type II fractures, the pore pressure increases and then becomes steady. However, the flow rate increases first and begins to decrease after the flow reaches the stop end of the fracture and finally vanishes. There is no obvious pore pressure or flow rate concentration within type III fractures.
基金Supported by the Natural Science Foundation of Jiangsu Province(BK2009434)the Innovation Platform for Public Health Emergency Preparedness and Response(NO.ZX201109)the Key Medical Talent Foundation of Jiangsu Province(RC2011084)
文摘Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3' end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.
基金Supported by the National Natural Science Foundation of China (No.60472104).
文摘This paper proposes Steepest Decreasing Constant Modulus Algorithm (SDCMA) detection in frequency dornain for MultiCarrier Direct Sequence-Code Division Multiple Access (MC DS-CDMA) systems. The proposed algorithm is used to equalize independent ladings of all subcarriers. At the same time we compare the SDCMA blind detection with subspace-based Minimum Mean-Squared Error (MMSE) detection. The simulation results show that the pertbrmance of SDCMA blind detection is superior to that of subspace-based MMSE detection and the complexity of the former is much lower than that of the latter.
基金supported by the National Basic Research Program of China("973"Program)(Grant No.2013GB10200)
文摘An effective method for eddy current calculation has been developed for EAST’s new divertor by using ANSYS.A 3D model of a double null divertor for the EAST device was built to evaluate eddy currents and electromagnetic(EM)forces on these components.The main input to the model is the plasma current and poloidal field coil currents,which are loaded into the model using experimental data measured from the EAST discharges.These currents generate magnetic fields that match those producing an EAST discharge,and the time variation of these fields produces the eddy currents in the divertors,along with from the resulting EM forces.In addition,the first 10 time steps were discussed for the eddy current generation and changing trend.It indicates that a static analysis before a transient mode start can solve the eddy current origination in the initial time steps.With this method,the EM transient response of EAST’s new divertor can be predicted based on ANSYS simulations.Furthermore,the method is also an effective approach to estimate the EM results for the in-vessel components of a fusion reactor during a disruption.