In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by re...In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors.展开更多
Objective Neurofibromatosis typeⅠ(NF1)is an autosomal dominant disorder which is caused by loss-of-function mutations in neurofibromin 1 gene(NF1).Clinically,NF1 mainly manifests several typical features,such as mult...Objective Neurofibromatosis typeⅠ(NF1)is an autosomal dominant disorder which is caused by loss-of-function mutations in neurofibromin 1 gene(NF1).Clinically,NF1 mainly manifests several typical features,such as multiple neurofibromas and café-au-lait spots,as well as axillary freckling and Lisch nodules in iris.The aim of the current study is to identification a splicing mutation and genotype-phenotype correlation.展开更多
We report the cloning and functional characterization of human cyclin L2, a novel member of the cyclin family. Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcri...We report the cloning and functional characterization of human cyclin L2, a novel member of the cyclin family. Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcriptional regulation via phosphorylation of the C-terminal domain of RNA polymerase Ⅱ. The cyclin L2 protein contains an N-terminal "cyclin box" and C-terminal dipeptide repeats of alternating arginines and serines, a hallmark of the SR family of splicing factors. A new isoform and the mouse homologue of human cyclin L2 have also been cloned in this study. Human cyclin L2 is expressed ubiquitously in normal human tissues and tumor cells. We show here that cyclin L2 co-localizes with splicing factors SC-35 and 9G8 within nuclear speckles and that it associates with hyperphosphorylated, but not hypophosphorylated, RNA polymerase Ⅱ and CDK p110 PITSLRE kinase via its N-terminal cyclin domains. It can also associate with the SC-35 and 9G8 through its RS repeat region. Recombinant cyclin L2 protein can stimulate in vitro mRNA splicing. Overexpression of human cyclin L2 suppresses the growth of human hepatocellular carcinoma SMMC 7721 cells both in vitro and in vivo, inducing cellular apoptosis. This process involves up-regulation of p53 and Bax and decreased expression of Bcl-2. The data suggest that cyclin L2 represents a new member of the cyclin family, which might regulate the transcription and RNA processing of certain apoptosis-related factors, resulting in tumor cell growth inhibition and apoptosis.展开更多
通过重叠延伸PCR(gene splicing by overlap extension,SOE-PCR)扩增黄曲霉寡聚-1,6-葡萄糖苷酶基因和酿酒酵母α-信号肽序列,定向重组到整合型表达载体pδRCMB中,并在CICC1346中实现分泌表达;然后通过同源建模、利用分子模拟软件Discov...通过重叠延伸PCR(gene splicing by overlap extension,SOE-PCR)扩增黄曲霉寡聚-1,6-葡萄糖苷酶基因和酿酒酵母α-信号肽序列,定向重组到整合型表达载体pδRCMB中,并在CICC1346中实现分泌表达;然后通过同源建模、利用分子模拟软件Discovery Studio 4.1分析其蛋白结构,以对硝基苯-α-D-葡萄糖吡喃苷(pNPG)为底物,建立并确定酶活反应条件,并进行纯化、酶学性质分析;将密码子优化后序列在CICC1346中实现分泌表达,利用淀粉进行共发酵实验。结果显示:重组酶突变后相对野生型蛋白结构无影响。SDS-PAGE分析重组重组酶大小约为70 kDa;优化后最高酶活达到0.69 U/m L,重组酶最适pH为6.5,在pH4.5.0~7.0维持90%以上的酶活;最适温度为40℃,在30~40℃维持接近100%的酶活;受Cu^(2+)和Mn^(2+)严格抑制;寡聚-1,6-葡萄糖苷酶与α-淀粉酶及糖化酶协同利用淀粉产乙醇,提高淀粉水解效率。这是首次报道黄曲霉的寡聚-1,6-葡萄糖苷酶基因在酿酒酵母整合型分泌表达。展开更多
Aiming at the problem of tool wear and breakage, the low accuracy of machined surface duringthe milling process of automobile panel splicing dies, the cutting force modeling of micro element is carriedout. The cutting...Aiming at the problem of tool wear and breakage, the low accuracy of machined surface duringthe milling process of automobile panel splicing dies, the cutting force modeling of micro element is carriedout. The cutting chip thickness of each cutting cycle is built as a function of the cutting angle and the shearforce according to the different hardness of machining materials, and a plow force model are obtained underng angles. By introducing a single degree of freedom italic collision model, the Hopkinsontest is used to obtain the elastic deformation δ of the tool workpiece impact under different spindle speeds,sults showforce on the tool in the transition area is obtained. Combining above models together,of milling force in the transition area can be obtained. Experiment and simulation reconslstendirections is studied. Fromcythto prove the accuracy of the model. The surface quality under different feede analysis results of machined surface quality, surfacedifference between workpieces, it is concluded that better surface quality can be obtaineness and heightness and low hardness workpiece. The results provide theoretical support for the optimizationing process in the splicing die of the automobile panel highof the milling process in the splicing die of the automobile panel.展开更多
This paper presents an integrated approach towards solving the problem of "Gene Prediction".The "Gene Prediction" problem solving undergoes well defined stages starting with a DNA
近日,胃肠病学和肝脏病学领域顶级期刊Gut（影响因子16.658）在线发表了浙江大学基础医学院、中国药科大学校长来茂德教授团队的最新研究成果——SRSF6-regulated alternative splicing that promotes tumour progression offers a ther...近日,胃肠病学和肝脏病学领域顶级期刊Gut（影响因子16.658）在线发表了浙江大学基础医学院、中国药科大学校长来茂德教授团队的最新研究成果——SRSF6-regulated alternative splicing that promotes tumour progression offers a therapy target for colorectal cancer。来茂德教授和张红河副教授为共同通信作者。展开更多
文摘In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors.
文摘Objective Neurofibromatosis typeⅠ(NF1)is an autosomal dominant disorder which is caused by loss-of-function mutations in neurofibromin 1 gene(NF1).Clinically,NF1 mainly manifests several typical features,such as multiple neurofibromas and café-au-lait spots,as well as axillary freckling and Lisch nodules in iris.The aim of the current study is to identification a splicing mutation and genotype-phenotype correlation.
文摘We report the cloning and functional characterization of human cyclin L2, a novel member of the cyclin family. Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcriptional regulation via phosphorylation of the C-terminal domain of RNA polymerase Ⅱ. The cyclin L2 protein contains an N-terminal "cyclin box" and C-terminal dipeptide repeats of alternating arginines and serines, a hallmark of the SR family of splicing factors. A new isoform and the mouse homologue of human cyclin L2 have also been cloned in this study. Human cyclin L2 is expressed ubiquitously in normal human tissues and tumor cells. We show here that cyclin L2 co-localizes with splicing factors SC-35 and 9G8 within nuclear speckles and that it associates with hyperphosphorylated, but not hypophosphorylated, RNA polymerase Ⅱ and CDK p110 PITSLRE kinase via its N-terminal cyclin domains. It can also associate with the SC-35 and 9G8 through its RS repeat region. Recombinant cyclin L2 protein can stimulate in vitro mRNA splicing. Overexpression of human cyclin L2 suppresses the growth of human hepatocellular carcinoma SMMC 7721 cells both in vitro and in vivo, inducing cellular apoptosis. This process involves up-regulation of p53 and Bax and decreased expression of Bcl-2. The data suggest that cyclin L2 represents a new member of the cyclin family, which might regulate the transcription and RNA processing of certain apoptosis-related factors, resulting in tumor cell growth inhibition and apoptosis.
文摘通过重叠延伸PCR(gene splicing by overlap extension,SOE-PCR)扩增黄曲霉寡聚-1,6-葡萄糖苷酶基因和酿酒酵母α-信号肽序列,定向重组到整合型表达载体pδRCMB中,并在CICC1346中实现分泌表达;然后通过同源建模、利用分子模拟软件Discovery Studio 4.1分析其蛋白结构,以对硝基苯-α-D-葡萄糖吡喃苷(pNPG)为底物,建立并确定酶活反应条件,并进行纯化、酶学性质分析;将密码子优化后序列在CICC1346中实现分泌表达,利用淀粉进行共发酵实验。结果显示:重组酶突变后相对野生型蛋白结构无影响。SDS-PAGE分析重组重组酶大小约为70 kDa;优化后最高酶活达到0.69 U/m L,重组酶最适pH为6.5,在pH4.5.0~7.0维持90%以上的酶活;最适温度为40℃,在30~40℃维持接近100%的酶活;受Cu^(2+)和Mn^(2+)严格抑制;寡聚-1,6-葡萄糖苷酶与α-淀粉酶及糖化酶协同利用淀粉产乙醇,提高淀粉水解效率。这是首次报道黄曲霉的寡聚-1,6-葡萄糖苷酶基因在酿酒酵母整合型分泌表达。
文摘Aiming at the problem of tool wear and breakage, the low accuracy of machined surface duringthe milling process of automobile panel splicing dies, the cutting force modeling of micro element is carriedout. The cutting chip thickness of each cutting cycle is built as a function of the cutting angle and the shearforce according to the different hardness of machining materials, and a plow force model are obtained underng angles. By introducing a single degree of freedom italic collision model, the Hopkinsontest is used to obtain the elastic deformation δ of the tool workpiece impact under different spindle speeds,sults showforce on the tool in the transition area is obtained. Combining above models together,of milling force in the transition area can be obtained. Experiment and simulation reconslstendirections is studied. Fromcythto prove the accuracy of the model. The surface quality under different feede analysis results of machined surface quality, surfacedifference between workpieces, it is concluded that better surface quality can be obtaineness and heightness and low hardness workpiece. The results provide theoretical support for the optimizationing process in the splicing die of the automobile panel highof the milling process in the splicing die of the automobile panel.
文摘This paper presents an integrated approach towards solving the problem of "Gene Prediction".The "Gene Prediction" problem solving undergoes well defined stages starting with a DNA
文摘近日,胃肠病学和肝脏病学领域顶级期刊Gut（影响因子16.658）在线发表了浙江大学基础医学院、中国药科大学校长来茂德教授团队的最新研究成果——SRSF6-regulated alternative splicing that promotes tumour progression offers a therapy target for colorectal cancer。来茂德教授和张红河副教授为共同通信作者。
