Single molecular real-time(SMRT)sequencing,also called third-generation sequencing,is a novel sequencing technique capable of generating extremely long contiguous sequence reads.While conventional short-read sequencin...Single molecular real-time(SMRT)sequencing,also called third-generation sequencing,is a novel sequencing technique capable of generating extremely long contiguous sequence reads.While conventional short-read sequencing cannot evaluate the linkage of nucleotide substitutions distant from one another,SMRT sequencing can directly demonstrate linkage of nucleotide changes over a span of more than 20 kbp,and thus can be applied to directly examine the haplotypes of viruses or bacteria whose genome structures are changing in real time.In addition,an error correction method(circular consensus sequencing)has been established and repeated sequencing of a single-molecule DNA template can result in extremely high accuracy.The advantages of long read sequencing enable accurate determination of the haplotypes of individual viral clones.SMRT sequencing has been applied in various studies of viral genomes including determination of the full-length contiguous genome sequence of hepatitis C virus(HCV),targeted deep sequencing of the HCV NS5A gene,and assessment of heterogeneity among viral populations.Recently,the emergence of multi-drug resistant HCV viruses has become a significant clinical issue and has been also demonstrated using SMRT sequencing.In this review,we introduce the novel third-generation PacBio RSII/Sequel systems,compare them with conventional next-generation sequencers,and summarize previous studies in which SMRT sequencing technology has been applied for HCV genome analysis.We also refer to another long-read sequencing platform,nanopore sequencing technology,and discuss the advantages,limitations and future perspectives in using these thirdgeneration sequencers for HCV genome analysis.展开更多
Dilated cardiomyopathy（DCM）is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM...Dilated cardiomyopathy（DCM）is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM concomitant with arrhythmias and sudden death resulting from gene mutation has been widely展开更多
In the search for a therapeutic schedule for spinal cord injury,it is necessary to understand key genes and their corresponding regulatory networks involved in the spinal cord injury process.However,ad hoc selection a...In the search for a therapeutic schedule for spinal cord injury,it is necessary to understand key genes and their corresponding regulatory networks involved in the spinal cord injury process.However,ad hoc selection and analysis of one or two genes cannot fully reveal the complex molecular biological mechanisms of spinal cord injury.The emergence of second-generation sequencing technology(RNA sequencing)has provided a better method.In this study,RNA sequencing technology was used to analyze differentially expressed genes at different time points after spinal cord injury in rat models established by contusion of the eighth thoracic segment.The numbers of genes that changed significantly were 944,1362 and 1421 at 1,4 and 7 days after spinal cord injury respectively.After gene ontology analysis and temporal expression analysis of the differentially expressed genes,C5ar1,Socs3 and CCL6 genes were then selected and identified by real-time polymerase chain reaction and western blot assay.The mRNA expression trends of C5ar1,Socs3 and CCL6 genes were consistent with the RNA sequencing results.Further verification and analysis of C5ar1 indicate that the level of protein expression of C5ar1 was consistent with its nucleic acid level after spinal cord injury.C5ar1 was mainly expressed in neurons and astrocytes.Finally,the gene Itgb2,which may be related to C5ar1,was found by Chilibot database and literature search.Immunofluorescence histochemical results showed that the expression of Itgb2 was highly consistent with that of C5ar1.Itgb2 was expressed in astrocytes.RNA sequencing technology can screen differentially expressed genes at different time points after spinal cord injury.Through analysis and verification,genes strongly associated with spinal cord injury can be screened.This can provide experimental data for further determining the molecular mechanism of spinal cord injury,and also provide possible targets for the treatment of spinal cord injury.This study was approved ethically by the Laboratory Animal Ethics Committee of Jiangsu Province,China(approval No.2018-0306-001)on March 6,2018.展开更多
Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of whic...Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of which emerge as outbreaks. In such situations, discovery of novel viruses is utmost important for deciding prevention and treatment strategies. Since last century, a number of different virus discovery methods, based on cell culture inoculation, sequence-independent PCR have been used for identification of a variety of viruses. However, the recent emergence and commercial availability of nextgeneration sequencers(NGS) has entirely changed the field of virus discovery. These massively parallel sequencing platforms can sequence a mixture of genetic materials from a very heterogeneous mix, with high sensitivity. Moreover, these platforms work in a sequenceindependent manner, making them ideal tools for virus discovery. However, for their application in clinics, sample preparation or enrichment is necessary to detect low abundance virus populations. A number of techniques have also been developed for enrichment or viral nucleic acids. In this manuscript, we review the evolution of sequencing; NGS technologies available today as well as widely used virus enrichment technologies. We also discuss the challenges associated with their applications in the clinical virus discovery.展开更多
A hepatitis C virus(HCV)cDNA fragment,534bp in length and designated asQ534,was obtained by PCR amplification with self-designed primers.Q534 was cloned in-to Hinc Ⅱ site of pUC18 and the recombinant plasmid pQ534 wa...A hepatitis C virus(HCV)cDNA fragment,534bp in length and designated asQ534,was obtained by PCR amplification with self-designed primers.Q534 was cloned in-to Hinc Ⅱ site of pUC18 and the recombinant plasmid pQ534 was then selected from thebacterial transformants.The sequence analysis indicated that Q534 was a cDNA fragmentof HCV core gene,and located in HCV genome from positions 320 to 853 incorrespondence with Chiron’s prototype sequence.The homologies between Q534 and theprototype at the levels of nucleotides and amino acids were 90.0% and 97.6%,respectively.The homologies of Q534 with Japanese HCV-J and HCV-BK strains were 96.6% and97.0% at the nucleotide level,and 98.2% and 98.8% at the amino acid level.In terms ofthe sequence,this Chinese HCV isolate should belong to HCV group Ⅱ.展开更多
DNA electrophoresis gel is an important biologically experimental technique and DNA sequencing can be defined by it. Traditionally, it is time consuming for biologists to exam the gel images by their eyes and often ha...DNA electrophoresis gel is an important biologically experimental technique and DNA sequencing can be defined by it. Traditionally, it is time consuming for biologists to exam the gel images by their eyes and often has human errors during the process. Therefore, automatic analysis of the gel image could provide more information that is usually ignored by human expert. However, basic tasks such as the identification of lanes in a gel image, easily done by human experts, emerge as problems that may be difficult to be executed automatically. In this paper, we design an automatic procedure to analyze DNA gel images using various image processing algorithms. Firstly, we employ an enhanced fuzzy c-means algorithm to extract the useful information from DNA gel images and exclude the undesired background. Then, Gaussian function is utilized to estimate the location of each lane of A, T, C, and G on the gels images automatically. Finally, the location of each band on the gel image can be detected accurately by tracing lanes, renewing lost bands, and eliminating repetitive bands.展开更多
Primers were designed according to the known sequences of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) genes of human, rat and pig. RT-PCR was then used to amplify porcine SREBP-1c gene with total RNA of s...Primers were designed according to the known sequences of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) genes of human, rat and pig. RT-PCR was then used to amplify porcine SREBP-1c gene with total RNA of spleen tissue. A 760 bp segment of cDNA was cloned and sequenced. Homogeneous comparison showed that the sequence of porcine SREBP-1c had 99.9% and 99.1% homogeneity with the two known partial mRNA sequences of porcine SREBP-1c gene. The complete cDNA was obtained mainly based on the known partial sequences, which has 3 830 bp, encoding 1 151 amino acids with a calculated molecular weight of 121 479 Da. It is the first time that we get complete encode sequence of porcine SREBP-1c gene. The complete cDNA sequence has high homogeneity with SREBP-1c gene of other species. A characteristic structure of HLH (Helix-Loop-Helix) and four transmembrane segments were found in the amino acids. The sequence had been submitted to GenBank (Accession No.NM_-214157).展开更多
The use of sequential stratigraphy concept, based on well logs, sedimentology, and biostratigraphy, has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mecha...The use of sequential stratigraphy concept, based on well logs, sedimentology, and biostratigraphy, has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mechanisms allows us to predict the hydrocarbon generation potential of source rocks. In the Ivorian offshore sedimentary basin, certain studies have contributed to understanding and characterizing the petroleum system. However, these previous works did not integrate biostratigraphic data to highlight sedimentary facies. This study, conducted on two wells in the Abidjan margin, is crucial as it helps us comprehend the geometry of fossil sediments in relation to sea level variations. It will also aid in reconstructing the basin-filling history and predicting the distribution of rocks capable of trapping oil, determining lowstand systems tracts (reservoir rocks), transgressive systems tracts, and highstand systems tracts (cap rocks). Lithological analysis revealed predominantly clayey sedimentation with sandy layers. Well log data facilitated the delineation of formation boundaries and highlighted reservoirs consisting of sands, sandstones, limestones, and occasionally intercalated shales. Integrating these analysis results with biostratigraphic interpretations based on foraminifera and palynomorphs revealed that the traversed formations were deposited in a transitional environment ranging from Coniacian to Maastrichtian ages. Applying sequential stratigraphy concept from well logging resolved dating issues encountered in microfossil-poor or microfossil-free zones. The results of the Coniacian-Maastrichtian age sequential subdivision were aligned with the chart.展开更多
Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) report...Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.展开更多
Cellular vehicle-to-everything(C-V2X) communications is regarded as a promising and feasible solution for 5G-enabled vehicular communications and networking. In this paper, we investigate the pilot design and channel ...Cellular vehicle-to-everything(C-V2X) communications is regarded as a promising and feasible solution for 5G-enabled vehicular communications and networking. In this paper, we investigate the pilot design and channel estimation problem in MIMO-OFDM-based C-V2X systems with severe co-channel interference due to spectrum reusing among different V2X communication links. By using zero-correlation zone(ZCZ) sequences, we provide an interference-free pilot design scheme and a corresponding time-domain(TD) correlation-based channel estimation(TD-CCE) method. We employ the ZCZ sequences from the same family set to be designed as the TD pilot symbols and guarantee the pilot sequeneces for neighboring V2X communication links are code-division multiplexing(CDM). The co-channel pilot interference of the deisgned pilot symbols can be effectively eliminated by exploiting the provided TD-CCE method. Simulation results indicate that the accuracy of channel estimation can be effectively improved by the proposed scheme, whose performance is close to that of the non-interference situation.展开更多
The sequences which consist of any segment of a chaos sequence are called asC-sequences. These sequences could be used as a kind of input signals to replace M-sequences in theprocess identification. This substitution ...The sequences which consist of any segment of a chaos sequence are called asC-sequences. These sequences could be used as a kind of input signals to replace M-sequences in theprocess identification. This substitution is theoretically proved to be feasible. InverseC-sequences are created in a way similar to inverse M-sequences to solve the problem thatC-sequences have non-ideal balance property, that is, the numbers of '0' and '1' are unequal.Besides its good pseudo-random property, the sequences have other advantages such as easy togenerate, varieties of the segment and adjustable cycle time.展开更多
In [3], they gave necessary and sufficient condition for T 1 C and then as applications T 1 C for weakly dependent sequences was established. In this note, based on Gozlan-L′eonard characterization for W 1 H -inequal...In [3], they gave necessary and sufficient condition for T 1 C and then as applications T 1 C for weakly dependent sequences was established. In this note, based on Gozlan-L′eonard characterization for W 1 H -inequalities, we extends this result to W 1 H inequalities.展开更多
[ Objective ] This study aimed to analyze genetic variation of ribosomal ITS region sequences in Channa argus, C moculata and C. asiatica, and to in- vestigate the phylogenetic relationship among Charma species based ...[ Objective ] This study aimed to analyze genetic variation of ribosomal ITS region sequences in Channa argus, C moculata and C. asiatica, and to in- vestigate the phylogenetic relationship among Charma species based on ITS sequences. [ Method] ITS sequences of three Channa species were amplified by PCR, cloned and assembled to obtain the full length of ITS sequences. [ Result] The full length of ITS sequences of C. argus, C. maculata and C. asiatica was 902, 927, and 902/903 bp, respectively. ITS sequences of C. argus, C. maculata and C. asiatica exhibited higher G ＋ C （72%） than A ＋ T. Interspecific nucleotide differences were significantly greater than intraspecific differences of these three Channa species. Thus, these remarkably differential ITS fragments could be used to identify C. argus, C. maculata and C. asiatica. Phylogenetic tree constructed by Neighbor-joining and Maximum Likehood methods showed that C. argus shared the lowest genetic distance with C. maculata and the highest genetic distance with C. asiatica. [ Conclusion] This study provided reference for classification, i- dentification, phylogenetic analysis and interspecific hybridization of Channa species.展开更多
Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/...Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S_1 = 42.77±0.08ppm, S_2 = 7.15±0.06 ppm, S_3 (s)= -4.08±0.02ppm, S_3 (t) =-3.09±0.20ppm,S_4 = 0.48±0.03ppm, S_5 = 0.26±0.05ppm. In o-dichloro-benzen-d_4 S_1(s)=44.79±0.61ppm, S_2=7.40±0.00ppm, S_3(s)=-4.51±0.17ppm, S_3(t)=-3.13 ±0.00 ppm, S_4 =0.63±0.04ppm, S_5=0.36±0.00ppm.Simultaneously the ^(13)CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.展开更多
For a given graph H, a graphic sequence π =(d1, d2, ···, dn) is said to be potentially H-graphic if π has a realization containing H as a subgraph. In this paper, we characterize the potentially C6+ P...For a given graph H, a graphic sequence π =(d1, d2, ···, dn) is said to be potentially H-graphic if π has a realization containing H as a subgraph. In this paper, we characterize the potentially C6+ P2-graphic sequences where C6+ P2 denotes the graph obtained from C6 by adding two adjacent edges to the three pairwise nonadjacent vertices of C6. Moreover, we use the characterization to determine the value of σ(C6+ P2, n).展开更多
文摘Single molecular real-time(SMRT)sequencing,also called third-generation sequencing,is a novel sequencing technique capable of generating extremely long contiguous sequence reads.While conventional short-read sequencing cannot evaluate the linkage of nucleotide substitutions distant from one another,SMRT sequencing can directly demonstrate linkage of nucleotide changes over a span of more than 20 kbp,and thus can be applied to directly examine the haplotypes of viruses or bacteria whose genome structures are changing in real time.In addition,an error correction method(circular consensus sequencing)has been established and repeated sequencing of a single-molecule DNA template can result in extremely high accuracy.The advantages of long read sequencing enable accurate determination of the haplotypes of individual viral clones.SMRT sequencing has been applied in various studies of viral genomes including determination of the full-length contiguous genome sequence of hepatitis C virus(HCV),targeted deep sequencing of the HCV NS5A gene,and assessment of heterogeneity among viral populations.Recently,the emergence of multi-drug resistant HCV viruses has become a significant clinical issue and has been also demonstrated using SMRT sequencing.In this review,we introduce the novel third-generation PacBio RSII/Sequel systems,compare them with conventional next-generation sequencers,and summarize previous studies in which SMRT sequencing technology has been applied for HCV genome analysis.We also refer to another long-read sequencing platform,nanopore sequencing technology,and discuss the advantages,limitations and future perspectives in using these thirdgeneration sequencers for HCV genome analysis.
基金the funds of "the Youth Fund of Nantong Health Bureau 2015",ID:WQ2015009
文摘Dilated cardiomyopathy（DCM）is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM concomitant with arrhythmias and sudden death resulting from gene mutation has been widely
基金supported by the National Natural Science Foundation of China,No.31570983(to XDW)the Priority Academic Program Development of Jiangsu Higher Education Institutes of China
文摘In the search for a therapeutic schedule for spinal cord injury,it is necessary to understand key genes and their corresponding regulatory networks involved in the spinal cord injury process.However,ad hoc selection and analysis of one or two genes cannot fully reveal the complex molecular biological mechanisms of spinal cord injury.The emergence of second-generation sequencing technology(RNA sequencing)has provided a better method.In this study,RNA sequencing technology was used to analyze differentially expressed genes at different time points after spinal cord injury in rat models established by contusion of the eighth thoracic segment.The numbers of genes that changed significantly were 944,1362 and 1421 at 1,4 and 7 days after spinal cord injury respectively.After gene ontology analysis and temporal expression analysis of the differentially expressed genes,C5ar1,Socs3 and CCL6 genes were then selected and identified by real-time polymerase chain reaction and western blot assay.The mRNA expression trends of C5ar1,Socs3 and CCL6 genes were consistent with the RNA sequencing results.Further verification and analysis of C5ar1 indicate that the level of protein expression of C5ar1 was consistent with its nucleic acid level after spinal cord injury.C5ar1 was mainly expressed in neurons and astrocytes.Finally,the gene Itgb2,which may be related to C5ar1,was found by Chilibot database and literature search.Immunofluorescence histochemical results showed that the expression of Itgb2 was highly consistent with that of C5ar1.Itgb2 was expressed in astrocytes.RNA sequencing technology can screen differentially expressed genes at different time points after spinal cord injury.Through analysis and verification,genes strongly associated with spinal cord injury can be screened.This can provide experimental data for further determining the molecular mechanism of spinal cord injury,and also provide possible targets for the treatment of spinal cord injury.This study was approved ethically by the Laboratory Animal Ethics Committee of Jiangsu Province,China(approval No.2018-0306-001)on March 6,2018.
基金Supported by The author’s laboratory is supported by the Defence Research and Development Organization(DRDO),Ministry of Defence,Government of India
文摘Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of which emerge as outbreaks. In such situations, discovery of novel viruses is utmost important for deciding prevention and treatment strategies. Since last century, a number of different virus discovery methods, based on cell culture inoculation, sequence-independent PCR have been used for identification of a variety of viruses. However, the recent emergence and commercial availability of nextgeneration sequencers(NGS) has entirely changed the field of virus discovery. These massively parallel sequencing platforms can sequence a mixture of genetic materials from a very heterogeneous mix, with high sensitivity. Moreover, these platforms work in a sequenceindependent manner, making them ideal tools for virus discovery. However, for their application in clinics, sample preparation or enrichment is necessary to detect low abundance virus populations. A number of techniques have also been developed for enrichment or viral nucleic acids. In this manuscript, we review the evolution of sequencing; NGS technologies available today as well as widely used virus enrichment technologies. We also discuss the challenges associated with their applications in the clinical virus discovery.
文摘A hepatitis C virus(HCV)cDNA fragment,534bp in length and designated asQ534,was obtained by PCR amplification with self-designed primers.Q534 was cloned in-to Hinc Ⅱ site of pUC18 and the recombinant plasmid pQ534 was then selected from thebacterial transformants.The sequence analysis indicated that Q534 was a cDNA fragmentof HCV core gene,and located in HCV genome from positions 320 to 853 incorrespondence with Chiron’s prototype sequence.The homologies between Q534 and theprototype at the levels of nucleotides and amino acids were 90.0% and 97.6%,respectively.The homologies of Q534 with Japanese HCV-J and HCV-BK strains were 96.6% and97.0% at the nucleotide level,and 98.2% and 98.8% at the amino acid level.In terms ofthe sequence,this Chinese HCV isolate should belong to HCV group Ⅱ.
文摘DNA electrophoresis gel is an important biologically experimental technique and DNA sequencing can be defined by it. Traditionally, it is time consuming for biologists to exam the gel images by their eyes and often has human errors during the process. Therefore, automatic analysis of the gel image could provide more information that is usually ignored by human expert. However, basic tasks such as the identification of lanes in a gel image, easily done by human experts, emerge as problems that may be difficult to be executed automatically. In this paper, we design an automatic procedure to analyze DNA gel images using various image processing algorithms. Firstly, we employ an enhanced fuzzy c-means algorithm to extract the useful information from DNA gel images and exclude the undesired background. Then, Gaussian function is utilized to estimate the location of each lane of A, T, C, and G on the gels images automatically. Finally, the location of each band on the gel image can be detected accurately by tracing lanes, renewing lost bands, and eliminating repetitive bands.
基金Item supported by national"973"program(No. 2004CB117500)national natural science foundation(No.30471237)
文摘Primers were designed according to the known sequences of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) genes of human, rat and pig. RT-PCR was then used to amplify porcine SREBP-1c gene with total RNA of spleen tissue. A 760 bp segment of cDNA was cloned and sequenced. Homogeneous comparison showed that the sequence of porcine SREBP-1c had 99.9% and 99.1% homogeneity with the two known partial mRNA sequences of porcine SREBP-1c gene. The complete cDNA was obtained mainly based on the known partial sequences, which has 3 830 bp, encoding 1 151 amino acids with a calculated molecular weight of 121 479 Da. It is the first time that we get complete encode sequence of porcine SREBP-1c gene. The complete cDNA sequence has high homogeneity with SREBP-1c gene of other species. A characteristic structure of HLH (Helix-Loop-Helix) and four transmembrane segments were found in the amino acids. The sequence had been submitted to GenBank (Accession No.NM_-214157).
文摘The use of sequential stratigraphy concept, based on well logs, sedimentology, and biostratigraphy, has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mechanisms allows us to predict the hydrocarbon generation potential of source rocks. In the Ivorian offshore sedimentary basin, certain studies have contributed to understanding and characterizing the petroleum system. However, these previous works did not integrate biostratigraphic data to highlight sedimentary facies. This study, conducted on two wells in the Abidjan margin, is crucial as it helps us comprehend the geometry of fossil sediments in relation to sea level variations. It will also aid in reconstructing the basin-filling history and predicting the distribution of rocks capable of trapping oil, determining lowstand systems tracts (reservoir rocks), transgressive systems tracts, and highstand systems tracts (cap rocks). Lithological analysis revealed predominantly clayey sedimentation with sandy layers. Well log data facilitated the delineation of formation boundaries and highlighted reservoirs consisting of sands, sandstones, limestones, and occasionally intercalated shales. Integrating these analysis results with biostratigraphic interpretations based on foraminifera and palynomorphs revealed that the traversed formations were deposited in a transitional environment ranging from Coniacian to Maastrichtian ages. Applying sequential stratigraphy concept from well logging resolved dating issues encountered in microfossil-poor or microfossil-free zones. The results of the Coniacian-Maastrichtian age sequential subdivision were aligned with the chart.
基金This study was supported by research grants from ICGEB Collaborative Research Program (CRP/CHN96-05) and from China Yunnan Provincial Science & Technology Commission International Collaborative Research Program (97C009).
文摘Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.
文摘Cellular vehicle-to-everything(C-V2X) communications is regarded as a promising and feasible solution for 5G-enabled vehicular communications and networking. In this paper, we investigate the pilot design and channel estimation problem in MIMO-OFDM-based C-V2X systems with severe co-channel interference due to spectrum reusing among different V2X communication links. By using zero-correlation zone(ZCZ) sequences, we provide an interference-free pilot design scheme and a corresponding time-domain(TD) correlation-based channel estimation(TD-CCE) method. We employ the ZCZ sequences from the same family set to be designed as the TD pilot symbols and guarantee the pilot sequeneces for neighboring V2X communication links are code-division multiplexing(CDM). The co-channel pilot interference of the deisgned pilot symbols can be effectively eliminated by exploiting the provided TD-CCE method. Simulation results indicate that the accuracy of channel estimation can be effectively improved by the proposed scheme, whose performance is close to that of the non-interference situation.
基金This work was financially supported by the National Natural Science Foundation of China (No.70071047, No.10247005)the Postdoctoral Science Foundation of China (No.2002032129)
文摘The sequences which consist of any segment of a chaos sequence are called asC-sequences. These sequences could be used as a kind of input signals to replace M-sequences in theprocess identification. This substitution is theoretically proved to be feasible. InverseC-sequences are created in a way similar to inverse M-sequences to solve the problem thatC-sequences have non-ideal balance property, that is, the numbers of '0' and '1' are unequal.Besides its good pseudo-random property, the sequences have other advantages such as easy togenerate, varieties of the segment and adjustable cycle time.
文摘In [3], they gave necessary and sufficient condition for T 1 C and then as applications T 1 C for weakly dependent sequences was established. In this note, based on Gozlan-L′eonard characterization for W 1 H -inequalities, we extends this result to W 1 H inequalities.
基金Supported by Shanghai University Knowledge Service Platform(ZF1206)Special Fund for Agricultural Fine Seed Project in Shandong Province‘Excellent Gene Resource Discovery and Innovative Germplasm Cultivation of Channa argus’Jinan Comprehensive Experimental Station of National Technology System for Conventional Freshwater Fish Industries(CARS-46-37)
文摘[ Objective ] This study aimed to analyze genetic variation of ribosomal ITS region sequences in Channa argus, C moculata and C. asiatica, and to in- vestigate the phylogenetic relationship among Charma species based on ITS sequences. [ Method] ITS sequences of three Channa species were amplified by PCR, cloned and assembled to obtain the full length of ITS sequences. [ Result] The full length of ITS sequences of C. argus, C. maculata and C. asiatica was 902, 927, and 902/903 bp, respectively. ITS sequences of C. argus, C. maculata and C. asiatica exhibited higher G ＋ C （72%） than A ＋ T. Interspecific nucleotide differences were significantly greater than intraspecific differences of these three Channa species. Thus, these remarkably differential ITS fragments could be used to identify C. argus, C. maculata and C. asiatica. Phylogenetic tree constructed by Neighbor-joining and Maximum Likehood methods showed that C. argus shared the lowest genetic distance with C. maculata and the highest genetic distance with C. asiatica. [ Conclusion] This study provided reference for classification, i- dentification, phylogenetic analysis and interspecific hybridization of Channa species.
文摘Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S_1 = 42.77±0.08ppm, S_2 = 7.15±0.06 ppm, S_3 (s)= -4.08±0.02ppm, S_3 (t) =-3.09±0.20ppm,S_4 = 0.48±0.03ppm, S_5 = 0.26±0.05ppm. In o-dichloro-benzen-d_4 S_1(s)=44.79±0.61ppm, S_2=7.40±0.00ppm, S_3(s)=-4.51±0.17ppm, S_3(t)=-3.13 ±0.00 ppm, S_4 =0.63±0.04ppm, S_5=0.36±0.00ppm.Simultaneously the ^(13)CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.
基金Foundation item： Supported by the National Natural Science Foundation of China（11101358） Supported by the Project of Fujian Education Department（JA11165）+1 种基金 Supported by the Project of Education Department of Fujian Province（JA12209） Supported by the Project of Zhangzhou Teacher＇s College（S11104）
文摘For a given graph H, a graphic sequence π =(d1, d2, ···, dn) is said to be potentially H-graphic if π has a realization containing H as a subgraph. In this paper, we characterize the potentially C6+ P2-graphic sequences where C6+ P2 denotes the graph obtained from C6 by adding two adjacent edges to the three pairwise nonadjacent vertices of C6. Moreover, we use the characterization to determine the value of σ(C6+ P2, n).
