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蛋白质结构域划分方法及在线服务综述 预览
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作者 王燕 石强 薛志东 《广州大学学报:自然科学版》 CAS 2019年第1期20-29,共10页
蛋白质结构域是研究蛋白质结构、功能与进化的基本单位,不同的结构域可组合出更为复杂的蛋白质分子.划分蛋白质结构域后,可以从结构域的角度研究蛋白质的结构、功能与进化,降低了研究复杂度.根据已知结构的蛋白质统计,有约40%的为多结... 蛋白质结构域是研究蛋白质结构、功能与进化的基本单位,不同的结构域可组合出更为复杂的蛋白质分子.划分蛋白质结构域后,可以从结构域的角度研究蛋白质的结构、功能与进化,降低了研究复杂度.根据已知结构的蛋白质统计,有约40%的为多结构域蛋白质,其中还存在一级结构上不临近的氨基酸序列出现在同一个结构域的情况,即不连续结构域.文章给出了当前国内外有关蛋白质结构域边界预测、不连续结构域检测及结构域数据库与在线服务的研究进展,供相关研究者参考. 展开更多
关键词 蛋白质 结构域 不连续结构域 预测 在线服务
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Molecular Mechanism of the Specificity of Protein Import into Chloroplasts and Mitochondria in Plant Cells
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作者 Dong Wook Lee Sumin Lee +4 位作者 Junho Lee Seungjin Woo Md.Abdur Razzak Alessandro Vitale Inhwan Hwang 《分子植物:英文版》 SCIE CAS CSCD 2019年第7期951-966,共16页
Plants possess both types of endosymbiotic organelles, chloroplasts and mitochondria. Transit peptides and presequences function as signal sequences for specific import into chloroplasts and mitochondria, respectively... Plants possess both types of endosymbiotic organelles, chloroplasts and mitochondria. Transit peptides and presequences function as signal sequences for specific import into chloroplasts and mitochondria, respectively. However, how these highly similar signal sequences confer the protein import specificity remains elusive. Here, we show that mitochondrial- or chloroplast-specific import involves two distinct steps, specificity determination and translocation across envelopes, which are mediated by the N-terminal regions and functionally interchangeable C-terminal regions, respectively, of transit peptides and presequences. A domain harboring multiple-arginine and hydrophobic sequence motifs in the N-terminal regions of presequences was identified as the mitochondrial specificity factor. The presence of this domain and the absence of arginine residues in the N-terminal regions of otherwise common targeting signals confers specificity of protein import into mitochondria and chloroplasts, respectively. AtToc159, a chloroplast import receptor, also contributes to determining chloroplast import specificity. We propose that common ancestral sequences were functionalized into mitochondrial- and chloroplast-specific signal sequences by the presence and absence, respectively, of multiple-arginine and hydrophobic sequence motifs in the N-terminal region. 展开更多
关键词 transit peptide presequence protein IMPORT into CHLOROPLASTS and MITOCHONDRIA N-terminal SPECIFICITY DOMAIN C-TERMINAL common translocation DOMAIN IMPORT SPECIFICITY determination
Comparative analysis of C-type lectin domain proteins in the ghost moth, Thitarodes xiaojinensis (Lepidoptera: Hepialidae)
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作者 Qian Meng Ji-Hong Zhang +5 位作者 Huan Zhang Gui-Ling Zhou Ruo-Yao Ni Yan-Ni Zhao Qi-Lian Qin Zhen Zou 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第3期453-465,共13页
Insects have a large family of C-type lectins involved in cell adhesion, pathogen recognition and activation of immune responses. In this study, 32 transcripts encoding C-type lectin domain proteins (CTLDPs) were iden... Insects have a large family of C-type lectins involved in cell adhesion, pathogen recognition and activation of immune responses. In this study, 32 transcripts encoding C-type lectin domain proteins (CTLDPs) were identified from the Thitarodes xiaojinensis transcriptome. According to their domain structures, six CTLDPs with one carbohydraterecognition domain (CRD) were classified into the CTL-S subfamily. The other 23 CTLDPs with two CRDs were grouped into the immulectin (IML) subfamily. The remaining three with extra regulatory domains were sorted into the CTL-X subfamily. Phylogenetic analysis showed that CTL-S and CTL-X members from different insects could form orthologous groups. In contrast, no T. xiaojinensis IML orthologues were found in other insects. Remarkable lineage-specific expansion in this subfamily was observed reflecting that these CTLDPs, as important receptors, have evolved diversified members in response to a variety of microbes. Prediction of binding ligands revealed that T. xiaojinensis, a coldadapted species, conserved the ability of CRDs to combine with Ca^2+ to keep its receptors from freezing. Comparative analysis of induction of CTLDP genes after different immune challenges indicated that IMLs might play critical roles in immune defenses. This study examined T. xiaojinensis CTLDPs and provides a basis for further studies of their characteristics. 展开更多
关键词 binding ligand carbohydrate-recognition DOMAIN C-type LECTIN DOMAIN protein expression profiling PHYLOGENETIC feature Thitarodes xiaojinensis
A modified domain reduction method for numerical simulation of wave propagation in localized regions 预览
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作者 Luo Chao Lou Menglin +1 位作者 Gui Guoqing Wang Hao 《地震工程与工程振动:英文版》 SCIE EI CSCD 2019年第1期35-52,共18页
A modified domain reduction method(MDRM) that introduces damping terms to the original DRM is presented in this paper. To verify the proposed MDRM and compare the computational accuracy of these two methods, a numeric... A modified domain reduction method(MDRM) that introduces damping terms to the original DRM is presented in this paper. To verify the proposed MDRM and compare the computational accuracy of these two methods, a numerical test is designed. The numerical results of the MDRM and DRM are compared using an extended meshed model. The results show that the MDRM significantly improved the computational accuracy of the DRM. Then, the MDRM is compared with two existing conventional methods, namely Liao’s transmitting boundary and viscous-spring boundary with Liu’s method. The MDRM shows its great advancement in computational accuracy, stability and range of applications. This paper also discusses the influence of boundary location on computational accuracy. It can be concluded that smaller models tend to have larger errors. By introducing two dimensionless parameters, φ1 and φ2, the rational distance between the observation point and the MDRM boundary is suggested. When φ1 >2 or φ2>13, the relative PGA error can be limited to 5%. In practice, the appropriate model size can be chosen based on these two parameters to achieve desired computational accuracy. 展开更多
关键词 MODIFIED DOMAIN REDUCTION METHOD DOMAIN REDUCTION METHOD VISCOUS BOUNDARY VISCOUS spring BOUNDARY transmitting BOUNDARY wave propagation
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Biholomorphic Mappings and the Extension Operators on New Hartogs Domains
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作者 Yan Yan CUI Chao Jun WANG Hao LIU 《数学学报:英文版》 SCIE CSCD 2019年第5期671-689,共19页
In this paper, we generalize the Roper-Suffridge operator on the extended Hartogs domains. By using the geometric properties and the growth theorems of subclasses of biholomorphic mappings, we obtain the generalized o... In this paper, we generalize the Roper-Suffridge operator on the extended Hartogs domains. By using the geometric properties and the growth theorems of subclasses of biholomorphic mappings, we obtain the generalized operators preserve the properties of parabolic and spirallike mappings of type β and order ρ, SΩ*(β, A, B), almost starlike mapping of complex order λ on ΩN under different conditions, and thus we get the corresponding results on the unit ball Bn in Cn. The conclusions lead to some known results. 展开更多
关键词 Biholomorphic MAPPING Roper-Suffridge OPERATOR Hartogs DOMAIN
In situ AFM investigation of dual-mode self-assembling peptide 预览
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作者 Yue-Xian Bao Ming Yuan +4 位作者 Qiqige Du Yu-Bo Li Jing-Yu Gao Abdul Jamil Khan Feng Zhang 《核技术:英文版》 SCIE CAS CSCD 2019年第8期1-11,共11页
Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-bu... Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-building blocks, can form nanostructures with different functions,either in solutions or on interfaces. Previously, we synthesized a short peptide with the inspiration of an Alzheimer’s disease-related peptide: amyloid β peptide(A-p),namely GAV-9, which can epitaxially self-assemble into regular nanofilaments on liquid-solid interfaces, and it was found that both the hydrophobicity and charge state of the interfaces can significantly influence its assembling behavior. It was also reported that another A-β-containing dipeptide, FF,can self-assemble into nanostructures in solutions. Owing to the close relationship between these two short peptides, it is interesting to conjugate them into a de novo peptide with two separated structural domains and study its self-assembling behavior. To this end, herein we have synthesized the GAV-FF peptide with a sequence of NH2-VGGAVVAGVFF-CONH2 and verified its selfassembling property using the in situ liquid-phase atomic force microscopy. The results show that the GAV-FF peptide can self-assemble into nanofilaments both in solutions and on aqueous-solid interfaces, but with different morphologies. The FF domain accelerates the template-assisted self-assembling(TASA) process of the GAV domain, which in return enhances the solubility of FF in aqueous solutions and further participates in the fibrillization of FF. The current results could help deepen the understanding of the aggregation mechanism of diseaserelated peptides and could also shed light on the strategies to create artificial bio-functional nanostructures/patterns,which hold a significant potential for biomedical applications. 展开更多
关键词 AMYLOID PEPTIDE Nanofilament SELFASSEMBLY Structural domain Atomic force MICROSCOPY
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细胞分裂周期蛋白42结构域突变真核表达质粒的构建与鉴定 预览
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作者 李振玲 王帝 +1 位作者 宋远见 王玉兰 《解剖学杂志》 CAS 2019年第3期249-252,共4页
目的:构建细胞分裂周期蛋白(Cdc42)的结构域突变质粒,即鸟嘌呤核苷酸交换因子(GEF)结构域突变质粒。方法:根据NCBI中小鼠Cdc42全长cDNA序列找到结构域GEF,将GEF的氨基酸突变成丙氨酸,根据突变后的序列设计引物,PCR扩增得到目的片段588bp... 目的:构建细胞分裂周期蛋白(Cdc42)的结构域突变质粒,即鸟嘌呤核苷酸交换因子(GEF)结构域突变质粒。方法:根据NCBI中小鼠Cdc42全长cDNA序列找到结构域GEF,将GEF的氨基酸突变成丙氨酸,根据突变后的序列设计引物,PCR扩增得到目的片段588bp,限制性内切酶EcoRI和HindⅢ双酶切后插入到编码红色荧光蛋白(RFP)和his标签的真核表达载体PM-his-RFP中,构建PM-his-Cdc42(GEF)-RFP重组质粒,进行酶切电泳及DNA测序验证。用脂质体介导方法将重组质粒瞬时转染HT22细胞,通过荧光显微镜观察转染效率。结果:经酶切及测序结果显示突变后结构域插入的位置和序列正确,成功构建Cdc42蛋白GEF结构域突变质粒;荧光结果表明,重组质粒顺利转染HT22细胞。结论:成功构建的Cdc42结构域突变质粒为Cdc42蛋白的功能研究提供有效的操作工具。 展开更多
关键词 细胞分裂周期蛋白 鸟嘌呤核苷酸交换因子 结构域 真核表达质粒 突变
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Optimized dithering technique in frequency domain for high-quality three-dimensional depth data acquisition
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作者 蔡宁 陈浙泊 +1 位作者 曹向群 林斌 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第8期124-131,共8页
On the basis of the objective functions,dithering optimization techniques can be divided into the intensity-based optimization technique and the phase-based optimization technique.However,both types of techniques are ... On the basis of the objective functions,dithering optimization techniques can be divided into the intensity-based optimization technique and the phase-based optimization technique.However,both types of techniques are spatial-domain optimization techniques,while their measurement performances are essentially determined by the harmonic components in the frequency domain.In this paper,a novel genetic optimization technique in the frequency domain is proposed for highquality fringe generation.In addition,to handle the time-consuming difficulty of genetic algorithm(GA),we first optimize a binary patch,then join the optimal binary patches together according to periodicity and symmetry so as to generate a full-size pattern.It is verified that the proposed technique can significantly enhance the measured performance and ensure the robustness to various amounts of defocusing. 展开更多
关键词 FRINGE generation GENETIC algorithm frequency DOMAIN 3D shape measurement
Stacking transition in rhombohedral graphite
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作者 Tataiana Latychevskaia Seok-Kyun Son +8 位作者 Yaping Yang Dale Chancellor Michael Brown Servet Ozdemir Ivan Madan Gabriele Berruto Fabrizio Carbone Artem Mishchenko Kostya S. Novoselov 《物理学前沿:英文版》 SCIE CSCD 2019年第1期67-73,共7页
Few-layer graphene (FLG) has recently been intensively investigated for its variable electronic properties, which are defined by a local atomic arrangement. While the most natural arrangement of layers in FLG is ABA (... Few-layer graphene (FLG) has recently been intensively investigated for its variable electronic properties, which are defined by a local atomic arrangement. While the most natural arrangement of layers in FLG is ABA (Bernal) stacking, a metastable ABC (rhombohedral) stacking, characterized by a relatively high-energy barrier, can also occur. When both types of stacking occur in one FLG device, the arrangement results in an in-plane heterostructure with a domain wall (DW). In this paper, we present two approaches to demonstrate that the ABC stacking in FLG can be controllably and locally turned into the ABA stacking. In the first approach, we introduced Joule heating, and the transition was characterized by 2D peak Raman spectra at a submicron spatial resolution. The transition was initiated in a small region, and then the DW was controllably shifted until the entire device became ABA stacked. In the second approach, the transition was achieved by illuminating the ABC region with a train of 790-nm-wavelength laser pulses, and the transition was visualized by transmission electron microscopy in both diffraction and dark-field imaging modes. Further, using this approach, the DW was visualized at a nanoscale spatial resolution in the dark-field imaging mode. 展开更多
关键词 graphene GRAPHITE van der WAALS HETEROSTRUCTURES domain wall Raman spectroscopy transmission ELECTRON microscopy ELECTRON diffraction structural TRANSITION
Alanine-substituted mutant on Gly^373 and Asn^375 of Cry1Ai-h-loop 2 causes reduction in both toxicity and binding against Helicoverpa armigera 预览
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作者 LIU Yu-xiao ZHOU Zi-shan +2 位作者 LIANG Ge-mei SONG Fu-ping ZHANG Jie 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第5期1064-1071,共8页
Cry1Ai-h-loop 2 is a mutant of Cry1Ai constructed by exchanging loop 2 from Cry1Ah protein and shows insecticidal activity against Helicoverpa armigera. The toxicity of Cry1 Ai-h-loop 2, in contrast to the very low to... Cry1Ai-h-loop 2 is a mutant of Cry1Ai constructed by exchanging loop 2 from Cry1Ah protein and shows insecticidal activity against Helicoverpa armigera. The toxicity of Cry1 Ai-h-loop 2, in contrast to the very low toxicity of Cry1Ai, is closely associated with the eleven residues in the loop 2 region. To characterize the key sites of loop 2 in Cry1Ai-h-loop 2, alaninesubstituted mutants were generated. The toxicity of these mutants against H. armigera indicated that dual-mutant on Gly^373 and Asn^375 caused a significant decrease in toxic activity. ELISA binding and competition binding assays demonstrated that the reduction of toxicity in the mutant of interest was correlated with decreased binding affinity. 展开更多
关键词 Bacillus THURINGIENSIS Cry1Ai Domain Ⅱ-loop2 HELICOVERPA ARMIGERA BINDING AFFINITY
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Terahertz radiation of a butterfly-shaped photoconductive antenna(invited) 预览
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作者 Jitao Zhang Mingguang Tuo +3 位作者 Min Liang Wei-Ren Ng Michael EGehm Hao Xin 《红外与激光工程》 EI CSCD 北大核心 2019年第4期9-17,共9页
The terahertz(THz) far-field radiation properties of a butterfly-shaped photoconductive antenna(PCA) were experimentally studied using a home-built THz time-domain spectroscopy(THz-TDS) setup.To distinguish the contri... The terahertz(THz) far-field radiation properties of a butterfly-shaped photoconductive antenna(PCA) were experimentally studied using a home-built THz time-domain spectroscopy(THz-TDS) setup.To distinguish the contribution of in-gap photocurrent and antenna structure to far-field radiation,polarization-dependent THz field was measured and quantified as the illuminating laser beam moved along the bias field within the gap region of electrodes. The result suggests that, although the far-field THz radiation originates from the in-gap photocurrent, the antenna structure of butterfly-shaped PCA dominates the overall THz radiation. In addition, to explore the impact of photoconductive material,radiation properties of butterfly-shaped PCAs fabricated on both low-temperature-grown GaAs(LT-GaAs) and semi-insulating GaAs(Si-GaAs) were characterized and compared. Consistent with previous experiments, it is observed that while Si-GaAs-based PCA can emit higher THz field than LT-GaAs-based PCA at low laser power, it would saturate more severely as laser power increased and eventually be surpassed by LT-GaAs-based PCA. Beyond that, it is found the severe saturation effect of Si-GaAs was due to the longer carrier lifetime and higher carrier mobility, which was confirmed by the numerical simulation. 展开更多
关键词 TERAHERTZ PHOTOCONDUCTIVE ANTENNA BUTTERFLY time domain SPECTROSCOPY
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LOW MACH NUMBER LIMIT OF A COMPRESSIBLE NON-ISOTHERMAL NEMATIC LIQUID CRYSTALS MODEL 预览
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作者 樊继山 栗付才 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第2期449-460,共12页
In this paper, we study the low Mach number limit of a compressible nonisothermal model for nematic liquid crystals in a bounded domain. We establish the uniform estimates with respect to the Mach number, and thus pro... In this paper, we study the low Mach number limit of a compressible nonisothermal model for nematic liquid crystals in a bounded domain. We establish the uniform estimates with respect to the Mach number, and thus prove the convergence to the solution of the incompressible model for nematic liquid crystals. 展开更多
关键词 COMPRESSIBLE NON-ISOTHERMAL liquid CRYSTALS BOUNDED domain low MACH number LIMIT
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Solution structure of the RNA recognition domain of METTL3-METTL14 N^6-methyladenosine methyltransferase
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作者 Jinbo Huang Xu Dong +8 位作者 Zhou Gong Ling-Yun Qin Shuai Yang Yue-Ling Zhu Xiang Wang Delin Zhang Tingting Zou Ping Yin Chun Tang 《蛋白质与细胞:英文版》 SCIE CAS CSCD 2019年第4期272-284,共13页
N^6-methyladenosine(m6A),a ubiquitous RNA modification,is installed by METTL3-METTL14 complex.The structure of the heterodimeric complex between the methyltransferase domains(MTDs)of METTL3 and METTL14 has been previo... N^6-methyladenosine(m6A),a ubiquitous RNA modification,is installed by METTL3-METTL14 complex.The structure of the heterodimeric complex between the methyltransferase domains(MTDs)of METTL3 and METTL14 has been previously determined.However,the MTDs alone possess no enzymatic activity.Here we present the solution structure for the zinc finger domain(ZFD)of METTL3,the inclusion of which fulfills the methyltransferase activity of METTL3-METTL14.We show that the ZFD specifically binds to an RNA containing 5'-GGACU-3'consensus sequence,but does not to one without.The ZFD thus serves as the target recognition domain,a structural feature previously shown for DNA methyltransferases,and cooperates with the MTDs of METTL3-METTL14 for catalysis.However,the interaction between the ZFD and the specific RNA is extremely weak,with the binding affinity at several hundred micromolar under physiological conditions.The ZFD contains two CCCH-type zinc fingers connected by an anti-parallel P-sheet.Mutational analysis and NMR titrations have mapped the functional interface to a contiguous surface.As a division of labor,the RNA-binding interface comprises basic residues from zinc finger 1 and hydrophobic residues fromβ-sheet and zinc finger 2.Further we show that the linker between the ZFD and MTD of METTL3 is flexible but partially folded,which may permit the cooperation between the two domains during catalysis.Together,the structural characterization of METTL3 ZFD paves the way to elucidate the atomic details of the entire process of RNA m6A modification. 展开更多
关键词 RNA modification N^6-methyladenosine METTL3 target recognition DOMAIN zinc FINGER PARAMAGNETIC RELAXATION enhancement
Reductivity and bundle shifts 预览
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作者 XU An-jian 《高校应用数学学报:英文版(B辑)》 SCIE CSCD 2019年第1期27-32,共6页
For the Hardy space HE^2(R)over a flat unitary vector bundle E on a finitely connected domain R,let TE be the bundle shift as[3].If B is a reductive algebra containing every operator(TE)for any rational function with ... For the Hardy space HE^2(R)over a flat unitary vector bundle E on a finitely connected domain R,let TE be the bundle shift as[3].If B is a reductive algebra containing every operator(TE)for any rational function with poles outside of R,then B is self adjoint. 展开更多
关键词 reductivity BUNDLE SHIFT multiply-connected DOMAIN
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Human Cyber Physical Systems(HCPSs)in the Context of New-Generation Intelligent Manufacturing 预览
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作者 Zhou Ji Zhou Yanhong +1 位作者 Wang Baicun Zang Jiyuan 《工程(英文)》 2019年第4期624-636,共13页
An intelligent manufacturing system is a composite intelligent system comprising humans,cyber systems,and physical systems with the aim of achieving specific manufacturing goals at an optimized level.This kind of inte... An intelligent manufacturing system is a composite intelligent system comprising humans,cyber systems,and physical systems with the aim of achieving specific manufacturing goals at an optimized level.This kind of intelligent system is called a human-cyber-physical system(HCPS).In terms of technology,HCPSs can both reveal technological principles and form the technological architecture for intelligent manufacturing.It can be concluded that the essence of intelligent manufacturing is to design,construct,and apply HCPSs in various cases and at different levels.With advances in information technology,intelligent manufacturing has passed through the stages of digital manufacturing and digital-networked manufacturing,and is evolving toward new-generation intelligent manufacturing(NGIM).NGIM is characterized by the in-depth integration of new-generation artificial intelligence(AI)technology(i.e.,enabling technology)with advanced manufacturing technology(i.e.,root technology);it is the core driving force of the new industrial revolution.In this study,the evolutionary footprint of intelligent manufacturing is reviewed from the perspective of HCPSs,and the implications,characteristics,technical frame,and key technologies of HCPSs for NGIM are then discussed in depth.Finally,an outlook of the major challenges of HCPSs for NGIM is proposed. 展开更多
关键词 New-generation intelligent manufacturing Human-cyber-physical system Human-physical system Cyber-physical system Knowledge engineering Enabling technology Manufacturing domain technology New-generation artificial intelligence
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水稻三结构域多铜氧化酶基因家族生物信息学分析
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作者 王有成 谭炎宁 +4 位作者 张超 殷小林 何强 肖应辉 邓华凤 《分子植物育种》 CAS CSCD 北大核心 2019年第5期1385-1392,共8页
三结构域多铜氧化酶是生物体内非常重要的金属氧化酶,对机体生长和发育具有重要影响。为了系统地了解水稻三结构域多铜氧化酶基因家族的基本情况,本研究运用生物信息学方法对其成员进行了预测和分析;研究发现,以拟南芥三结构域多铜氧化... 三结构域多铜氧化酶是生物体内非常重要的金属氧化酶,对机体生长和发育具有重要影响。为了系统地了解水稻三结构域多铜氧化酶基因家族的基本情况,本研究运用生物信息学方法对其成员进行了预测和分析;研究发现,以拟南芥三结构域多铜氧化酶基因At5g21105为靶序列,利用BlastP为工具在水稻基因组中共搜索到38个同源基因;这些基因的蛋白产物都依次含有Cu-oxidase3、Cu-oxidase和Cu-oxidase2三种结构域,各结构域中含有铜离子结合位点,二级结构具有α-螺旋和β-转角等基本特征,特推断它们都属于三结构域多铜氧化酶家族成员;进一步地,根据同源性程度将水稻多铜氧化酶基因家族成员划分为ClassⅠ和ClassⅡ两个亚家族,其中ClassⅠ包含31个基因,ClassⅡ包含7个基因。这些研究结果为进一步研究水稻多铜氧化酶基因家族成员的功能提供了参考依据。 展开更多
关键词 水稻 多铜氧化酶 基因家族 结构域 生物信息学分析
Field-variable magnetic domain characterization of individual 10 nm Fe3O4 nanoparticles
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作者 李正华 李翔 陆伟 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期470-474,共5页
The local detection of magnetic domains of isolated 10 nm Fe3O4 magnetic nanoparticles(MNPs) has been achieved by field-variable magnetic force microscopy(MFM) with high spatial resolution.The domain configuration of ... The local detection of magnetic domains of isolated 10 nm Fe3O4 magnetic nanoparticles(MNPs) has been achieved by field-variable magnetic force microscopy(MFM) with high spatial resolution.The domain configuration of an individual MNP shows a typical dipolar response.The magnetization reversal of MNP domains is governed by a coherent rotation mechanism, which is consistent with the theoretical results given by micromagnetic calculations.Present results suggest that the field-variable MFM has great potential in providing nanoscale magnetic information on magnetic nanostructures,such as nanoparticles, nanodots, skyrmions, and vortices, with high spatial resolution.This is crucial for the development and application of magnetic nanostructures and devices. 展开更多
关键词 Fe3O4 nanoparticles MAGNETIC force MICROSCOPY MAGNETIC DOMAIN
Screening the RFX6-DNA binding domain for potential genetic variants in patients with type 2 diabetes 预览
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作者 Ismail S Mahmoud Ayat Homsi +6 位作者 Hamzeh J Al-Ameer Jihad Alzyoud Mais Darras Mohammad Al Shhab Malek Zihlif Ma’mon M Hatmal Walhan Alshaer 《世界糖尿病杂志:英文版(电子版)》 2019年第3期181-187,共7页
BACKGROUND The regulatory factor X6 (RFX6), a member of regulatory factor X family, is known to play a key role in the development and differentiation of pancreatic beta cells as well as insulin production and secreti... BACKGROUND The regulatory factor X6 (RFX6), a member of regulatory factor X family, is known to play a key role in the development and differentiation of pancreatic beta cells as well as insulin production and secretion. However, the potential role of RFX6 in type 2 diabetes (T2D) is still unclear. AIM Recent studies have indicated that RFX6 binding to DNA could be disrupted in diabetes. Therefore, in this study we investigated whether genetic mutations are present in the DNA binding domain of RFX6 gene that could abrogate its function in T2D. METHODS A cohort of T2D patients was enrolled in this study, and the gene encoding the DNA binding domain of RFX6 was amplified by polymerase chain reaction and then analysed by direct DNA sequencing. RESULTS The DNA sequence analysis revealed the absence of any exonic mutation. However, we have identified a new heterozygous single nucleotide polymorphism (IVS6+31 C>T) in the intronic region of DNA binding domain gene that is present in 9.2% and 8.5% of diabetic and control people, respectively (P = 0.97).CONCLUSION We report the absence of any significant genetic variant that could affect the function of RFX6-DNA binding domain in T2D. 展开更多
关键词 REGULATORY factor X6 GENETIC VARIANT DIABETES DNA BINDING domain
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Characteristic signal extracted from a continuous time signal on the aspect of frequency domain
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作者 杜志凡 张瑞浩 陈红 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第9期124-130,共7页
Extracting characteristic signal from a continuous signal can effectively reduce the difficulty of analyzing the running states of a single-variable nonlinear system.Whether the extracted characteristic signal can acc... Extracting characteristic signal from a continuous signal can effectively reduce the difficulty of analyzing the running states of a single-variable nonlinear system.Whether the extracted characteristic signal can accurately reflect the running states of the system is very important.In this paper, a method called automatic sampling method(ASM) for extracting characteristic signals is investigated.The complete definition is described, the effectiveness is proved theoretically, and the general formulas of the extracted characteristic signals are derived for the first time.Furthermore, typical Chua's circuit is used to accomplish a lot of experimental research on the aspect of frequency domain.The experimental results show that ASM is feasible and practical, and can automatically generate a characteristic signal with the change of the original signal. 展开更多
关键词 automatic sampling method CHARACTERISTIC SIGNAL FREQUENCY DOMAIN system STATES
Anti-inflammatory Effect of Total Saponin Fraction from Dioscorea nipponica Makino on Gouty Arthritis and Its Influence on NALP3 Inflammasome
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作者 ZHOU Qi YU Dong-hua +1 位作者 ZHANG Ning LIU Shu-min 《中国结合医学杂志:英文版》 SCIE CAS CSCD 2019年第9期663-670,共8页
Objective: To investigate the mechanism of Chinese herbal medicine Dioscorea nipponica for the treatment of monosodium urate crystals-induced gouty arthritis(GA) in rats. Methods: Sixty male Wistar rats were divided i... Objective: To investigate the mechanism of Chinese herbal medicine Dioscorea nipponica for the treatment of monosodium urate crystals-induced gouty arthritis(GA) in rats. Methods: Sixty male Wistar rats were divided into 6 groups: normal, model, indomethacin and three total saponin(900, 300 and 100 mg/kg) groups. The liver, kidney and serum levels of lysosomal enzymes, antioxidant capacities, and inflammatory factors were measured. In addition, the m RNA and protein levels of the NALP3 inflammasome components in the mononuclear cells of rats’ peripheral blood were analyzed using real-time polymerase chain reaction and Western blotting methods, respectively. Results: Total saponins groups could reduce the activities of β-galactosidase,β-N acetyl glucosamine enzyme,β-glucuronidase, acid phosphatase, and malonaldehyde as wel as the contents of TNF-α, IL-1β and IL-8(all P<0.05). They could also increase the activities of glutathione peroxidase and total superoxide dismutase(both P<0.05). Further studies showed that total saponins groups of high, middle and low doses could all increase the m RNA and protein levels of caspase-1, adapter apoptosis-associated speck-like protein containing a caspase-recruitment domain(ASC) and NALP3 in the mononuclear cells of peripheral blood(all P<0.05). Conclusion: Dioscorea nipponica may treat GA by regulating lysosomal enzymes, antioxidant capacities and the NALP3 inflammasome. 展开更多
关键词 apoptosis-associated speck-like protein containing a caspase-recruitment domain caspase-1 Chinese medicine DIOSCOREA nipponica NALP3
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