检索结果-南通市图书馆

A new era for paclitaxel biosynthesis is coming

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2024年第3期17卷 370-371页

作者： Xiaonan Liu Xiaoxi zhu jian Cheng Huifeng jiang Key Laboratory of Engineering Biology for Low-carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Center of Technology Innovation for Synthetic Biology Tianjin 300308China

Paclitaxel(Taxol)stands out as a tetracyclic diterpenoid natural product derived from the endangered plant *** as a pivotal broad-spectrum anticancer drug,it has garnered widespread attention due to its low yield,intricate structure,unique anticancer mechanism,and remarkable efficacy(Tong et al.,2021).Although chemists achieved the total synthesis of paclitaxel 30 years ago,after decades of research,the natural biosynthetic pathway for its production remains an enigma(Ajikumar et al.,2010;Malci et al.,2023).A recent breakthrough,published in Molecular Plant by Alisdair ***'s team,unveils a minimal gene set of 18 genes required for paclitaxel biosynthesis(Zhang et al.,2023),representing a significant mark toward unraveling the entire biosynthetic pathway and enhancing paclitaxel production efficiency.

关键词： breakthrough representing synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

用于机器人视觉的大景深便携式三维扫描系统

光电工程 2006年第10期33卷 72-78页

作者：陈力汤青李剑峰朱建华四川大学物理科学与技术学院

针对机器人视觉对便携式三维扫描系统的大景深要求,利用Scheimpflug条件对CCD平面进行偏转,成功地将扫描系统的景深从30mm提高到了100mm以上;并根据CCD偏转后的摄像机模型,在理论上完整地推导了便携式集成三维扫描系统的物像关系方程。... 详细信息

针对机器人视觉对便携式三维扫描系统的大景深要求,利用Scheimpflug条件对CCD平面进行偏转,成功地将扫描系统的景深从30mm提高到了100mm以上;并根据CCD偏转后的摄像机模型,在理论上完整地推导了便携式集成三维扫描系统的物像关系方程。针对景深扩大后带来的测量精度降低的问题,提出了一种对系统全景深范围进行分段校准的新方法,提高了测量精度与系统分辨率。三维重建时,根据被扫描物体所对应的图像点在像平面上的不同位置分别调用不同的标定参数将二维图像坐标转变为物体的空间坐标,测量精度可以达到0.06mm。

关键词：三维扫描系统机器视觉三维重建三维检测

MPTA型原油脱金属剂对20^#碳钢腐蚀性影响的研究

在线全文

学校读者我要写书评

暂无评论

腐蚀科学与防护技术 2008年第3期20卷 209-212页

作者：高辉朱建华中国石油大学化工学院北京102249

采用静态密闭浸泡实验法,借鉴炼厂原油预处理过程中"一脱三注"的经验,从注水、注碱及注缓蚀剂三方面研究降低MPTA型脱金属剂溶液对常用20#碳钢的腐蚀可能性.结果表明,目前三种方法均不能有效地控制MPTA型脱金属剂溶液对20#碳钢的腐蚀,... 详细信息

采用静态密闭浸泡实验法,借鉴炼厂原油预处理过程中"一脱三注"的经验,从注水、注碱及注缓蚀剂三方面研究降低MPTA型脱金属剂溶液对常用20#碳钢的腐蚀可能性.结果表明,目前三种方法均不能有效地控制MPTA型脱金属剂溶液对20#碳钢的腐蚀,其中注碱和注缓蚀剂不当甚至会加剧对20#碳钢的腐蚀.研究认为,可能是由于MPTA型脱金属剂复杂的物性及对碳钢的腐蚀机理所致.

关键词：原油脱金属剂腐蚀 20^#碳钢缓蚀剂

The RNA-binding domain of DCL3 is required for long-distance RNAi signaling

在线全文

学校读者我要写书评

暂无评论

aBIOTECH 2024年第1期5卷 17-28页

作者： Jie Li Bo-Sen Zhang hua-Wei Wu Cheng-Lan Liu Hui-Shan Guo jian-hua Zhao State Key Laboratory of Plant Genomics Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Biotic Interactions University of the Chinese Academy of SciencesBeijing 100049China Qilu Zhongke Academy of Modern Microbiology Technology Jinan 250022China

Small RNA(sRNA)-mediated RNA silencing(also known as RNA interference,or RNAi)is a conserved mechanism in eukaryotes that includes RNA degradation,DNA methylation,heterochromatin formation and protein translation *** plants,sRNAs can move either cell-to-cell or systemically,thereby acting as mobile silencing signals to trigger noncell autonomous ***,whether and what proteins are also involved in noncell autonomous silencing have not been *** this study,we utilized a previously reported inducible RNAi plant,PDSi,which can induce systemic silencing of the endogenous PDS gene,and we demonstrated that DCL3 is involved in systemic PDS silencing through its RNA binding *** confirmed that the C-terminus of DCL3,including the predicted RNA-binding domain,is capable of binding short *** affecting RNA binding,but not processing activity,reduced systemic PDS silencing,indicating that DCL3 binding to RNAs is required for the induction of systemic *** mosaic virus infection assays showed that the RNA-binding activity of DCL3 is required for antiviral RNAi in systemically noninoculated *** findings demonstrate that DCL3 acts as a signaling agent involved in noncell autonomous silencing and an antiviral effect in addition to its previously known function in the generation of 24-nucleotide sRNAs.

关键词： RNAi signaling DCL3 RBD RNAs Cucumber mosaic virus

Evolution of MnO–SiO2–Al_(2)O_(3)–MgO inclusions during heat treatment at 1100℃

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第5期31卷 1221-1231页

作者： Xu-bo Lei jian-li Li Qiang Zeng Hang-yu zhu Yue Yu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina

To investigate the evolutionary behavior of the MnO–SiO_(2)–Al_(2)O_(3)–MgO inclusions during heat treatment,water quenched samples were isothermally held at 1100°C for 120 min in Ar and air atmosphere,and the obtaining samples were analyzed by X-ray diffraction,scanning electron microscopy and energy dispersive *** showed that 3MnO·Al_(2)O_(3)·3SiO_(2)and MnO·SiO_(2)were detected in the 5 wt.%MgO system after isothermal holding in Ar atmosphere,while MgO·Al_(2)O_(3),MnO·SiO_(2)and Mn7O8·SiO4 were detected in air *** evolutionary behavior of the 10,15 and 20 wt.%MgO systems after isothermal holding in different atmosphere were *** affected the solid phase transformation of the low MgO content *** calculation results of FactSage 8.1 showed that MgO·Al_(2)O_(3)was formed in the 5 wt.%MgO system with air *** solid phase transformation was accompanied by grain coarsening during the isothermal holding *** differences in the solid phase transformation in different atmosphere of the 5 wt.%MgO system indicated that it was a gas-phase transport grain coarsening *** enrichment of Al element in the liquid phase region at the grain edges,the homogeneous distribution of Mg element and the disappearance of the liquid phase within the crystal revealed that other MgO content systems were liquid–solid transport grain coarsening mechanism.

关键词： Evolution Glassy phase Inclusion Heat treatment MgO·Al_(2)O_(3)

Danhongqing formula alleviates cholestatic liver fibrosis by downregulating long non-coding RNA H19 derived from cholangiocytes and inhibiting hepatic stellate cell activation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第2期22卷 188-198页

作者： Meng Li Yang Zhou Hui zhu Lie-ming Xu jian Ping Institute of Liver Diseases Shuguang HospitalShanghai University of Traditional Chinese MedicineShanghai 201203China Preventive Treatment Center Yueyang Hospital of Integrated Traditional Chinese and Western MedicineShanghai University of Traditional Chinese MedicineShanghai 200437 China Department of Gastroenterology Suzhou Traditional Chinese Medicine HospitalSuzhou 215000Jiangsu ProvinceChina Shanghai Key Laboratory of Traditional Chinese Medicine Shanghai 201203China Key Laboratory of Liver and Kidney Diseases(Ministry of Education) Shanghai 201203China

Objective:This study explores the mechanism of action of Danhongqing formula(DHQ),a compoundbased Chinese medicine formula,in the treatment of cholestatic liver ***:In vivo experiments were conducted using 8-week-old multidrug resistance protein 2 knockout(Mdr2-/-)mice as an animal model of cholestatic liver *** was administered orally for 8 weeks,and its impact on cholestatic liver fibrosis was evaluated by assessing liver function,liver histopathology,and the expression of liver fibrosis-related ***-time polymerase chain reaction,Western blot,immunohistochemistry and other methods were used to observe the effects of DHQ on long non-coding RNA H19(H19)and signal transducer and activator of transcription 3(STAT3)phosphorylation in the liver tissue of Mdr2-/-*** addition,cholangiocytes and hepatic stellate cells(HSCs)were cultured in vitro to measure the effects of bile acids on cholangiocyte injury and H19 *** overexpressing H19 were constructed,and a conditioned medium containing H19 was collected to measure its effects on STAT3 protein expression and cell *** intervention effect of DHQ on these processes was also *** overexpressing H19 were constructed to measure the impact of H19 on cell activation and assess the intervention effect of ***:DHQ alleviated liver injury,ductular reaction,and fibrosis in Mdr2-/-mice,and inhibited H19expression,STAT3 expression and STAT3 *** formula also reduced hydrophobic bile acid-induced cholangiocyte injury and the upregulation of H19,inhibited the activation of HSCs induced by cholangiocyte-derived conditioned medium,and decreased the expression of activation markers in *** overexpression of H19 in a human HSC line confirmed that H19 promoted STAT3 phosphorylation and HSC activation,and DHQ was able to successfully inhibit these ***:DHQ effectively alleviated spontaneous cholestatic liver fibrosis in Md

关键词： Liver cirrhosis biliary Long non-coding RNA H19 Danhongqing formula Cholangiocyte Hepatic stellate cells STAT3 transcription factor

5-溴水杨醛缩乙醇胺Schiff碱Cu(Ⅱ)配合物的合成和晶体结构

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2006年第1期22卷 115-118页

作者：梁芳珍马建平朱建华山东师范大学化学化工与材料科学学院济南250014

The title complex Cu(L)2 [HL=N-(5-bromosalicylidene)-2-aminoethanol] was synthesized by the reaction of Cu(CH3COO)2·H2O with N-(5-bromosalicylidene)-2-aminoethanol in the ethanol. It was characterized by ele- mental analysis, IR and X-ray single crystal diffraction analysis. The crystal of the title complex [Cu(C9H9BrNO2)2] belongs tomonoclinic, space group P21/ n with a=1.319 1(5)nm, b=0.444 58(16)nm, c=1.656 7(6)nm, β=91.226(5)°, V=0.97146(6) nm3, Z=2, Dc=1.879 Mg·m-3, μ=5.264 mm-1, F(000)=542, and final R1=0.0456, wR2=0.0970. The complex comprises a four-coordinated copper! center, with an N2O2 planar coordination environment. The molecules are connected by hydrogen bonds to form two-dimensional layered structure. CCDC: 274180.

关键词： 5-溴水杨醛缩乙醇胺铜(Ⅱ)配合物晶体结构合成

在线全文

学校读者我要写书评

暂无评论

一种抗阻断攻击的多方密钥协商协议

电子学报 2008年第7期36卷 1368-1372页

作者：郑明辉崔国华祝建华华中科技大学计算机科学与技术学院

一个非认证的多方密钥协商协议不能对通信参与方和消息进行认证,它必须依赖认证的网络信道或其他的认证方法.分析了Horng在认证广播信道下提出的高效多方密钥协商协议,指出它不能抵抗内部恶意参与方发起的密钥协商阻断攻击,该攻击导致... 详细信息

一个非认证的多方密钥协商协议不能对通信参与方和消息进行认证,它必须依赖认证的网络信道或其他的认证方法.分析了Horng在认证广播信道下提出的高效多方密钥协商协议,指出它不能抵抗内部恶意参与方发起的密钥协商阻断攻击,该攻击导致通信的其他诚实参与方不能正确计算出相同的共享密钥.提出了一种安全的多方密钥协商协议,在Horng协议中加入了消息正确性的认证方法,能够检测出组内恶意参与方,并在随机预言模型下证明了提出的协议能够抵抗密钥协商阻断攻击.

关键词：密钥协商离散对数问题阻断攻击随机预言模型

Successful splenic artery embolization in a patient with Behçet’s syndrome-associated splenic rupture:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第4期16卷 1184-1188页

作者： Guang-Zhao zhu Dong-hua Ji Department of Interventional Therapy The First Affiliated Hospital of Dalian Medical UniversityDalian 116011Liaoning ProvinceChina

BACKGROUND Splenic rupture associated with Behçet’s syndrome(BS)is extremely rare,and there is no consensus on its *** this case report,a patient with BSassociated splenic rupture was successfully treated with splenic artery embolization(SAE)and had a good prognosis after the *** SUMMARY The patient was admitted for pain in the left upper abdominal *** was diagnosed with splenic *** oral and genital aphthous ulcers were observed,and acne scars were found on his *** had a 2-year history of BS diagnosis,with symptoms of oral and genital *** that time,he was treated with oral corticosteroids for 1 month,but the symptoms did not *** underwent SAE to treat the *** the first day after SAE,the patient reported a complete resolution of abdominal pain and was discharged 5 d *** months after the intervention,a computed tomography examination showed that the splenic hematoma had formed a stable cystic effusion,suggesting a good *** SAE might be a good choice for BS-associated splenic rupture based on good surgical practice and material selection.

关键词： Splenic artery embolization Behçet’s syndrome Splenic rupture Case report