检索结果-南通市图书馆

Nucleos(t)ide analogues causes HBV S gene mutations and carcinogenesis

Hepatobiliary & Pancreatic Diseases International 2016年第6期15卷 579-586页

作者： meng-lan Wang Hong Tang Center of Infectious Diseases West China Hospital of Sichuan University Division of Infectious Diseases State Key Laboratory of Biotherapy and Cancer CenterWest China Hospital of Sichuan Universityand Collaborative Innovation Center for Biotherapy

BACKGROUND： The long-term use of nudeos（t）ide analogues causes drug resistance and mutations in the HBV reverse tran- scriptase （RT） region of the polymerase gene. The RT region overlaps the HBV surface gene （S gene） and therefore, the mutations in the RT region simultaneously modify S gene sequence. Certain mutations in the RT region bring about truncated S proteins because the corresponding changed S gene encodes a stop codon which results in the loss of a large portion of the C-terminal hydrophobic region of HBV surface protein. The rtA181T/sW172＊, rtM204I/sW196＊ and rtV191I/sW182＊ are the most frequently reported drug-resistant mutations with C-terminal truncation, these mutations have oncogenic potential. DATA SOURCES： PubMed and Web of Science were searched using terms：＂hepatitis B virus＂, ＂HBV drug resistance mutation＂＂HBV surface protein＂＂HBV truncation＂, ＂hepatocellular carcinoma＂, ＂rtA181T/sW172＊＂, ＂rtM204I/sW196＊＂, ＂rtV191I/sW182＊＂, and relevant articles published in English in the past decades were reviewed. RESULTS： The rtA181T/sW172＊ and rtV191I/sW182＊ mutants occurred more frequently than the rtM204I/sW196＊ mutant both in chronic hepatitis B patients and the HBV-related hepatocellular carcinoma tissues. Although these mutations occur naturally, nudeos（t）ide analogues therapy is the main driving force. These mutations may exist alone or coexist with other HBV mutations. All these three mutants impair the virion secretion and result in HBV surface protein retention and serum HBV DNA level reduction. These mutations possess potential carcinogenic properties. The three mutations are resistant to more than one nucleos（t）ide analogue and therefore, it is difficult to treat the patients with the truncated ***： Nucleos（t）ide analogues induce drug resistance and HBV S gene truncated mutations. These mutations have potential carcinogenesis.

关键词： hepatitis B virus drug resistance mutation surface protein C-terminal truncation oncogenic potential hepatocellular carcinoma

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Geometrically invariant color image watermarking scheme using feature points

引用

Science in China(Series F) 2009年第9期52卷 1605-1616页

作者： WANG XiangYang meng lan YANG HongYing School of Computer and Information Technology Liaoning Normal University Dalian 116029 China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

Geometric distortion is known as one of the most difficult attacks to resist. Geometric distortion desynchronizes the location of the watermark and hence causes incorrect watermark detection. In this paper, we propose a geometrically invariant digital watermarking method for color images. In order to synchronize the location for watermark insertion and detection, we use a multi-scale Harris-Laplace detector, by which feature points of a color image can be extracted that are invariant to geometric distortions. Then, the self-adaptive local image region （LIR） detection based on the feature scale theory was considered for watermarking. At each local image region, the watermark is embedded after image normalization. By binding digital watermark with invariant image regions, resilience against geometric distortion can be readily obtained. Our method belongs to the category of blind watermarking techniques, because we do not need the original image during detection. Experimental results show that the proposed color image watermarking is not only invisible and robust against common signal processing such as sharpening, noise adding, and JPEG compression, but also robust against the geometric distortions such as rotation, translation, scaling, row or column removal, shearing, and local random bend.

关键词： image watermarking geometric distortion color image feature point image normalization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deciphering nucleic acid modifications by chemical derivatization-mass spectrometry analysis

引用

Chinese Chemical Letters 2019年第1期30卷 1-6页

作者： meng-Dan lan Bi-Feng Yuan Yu-Qi Feng Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) Department of Chemistry Wuhan University

Now increasing chemical modifications are discovered on genomic DNA and RNA. Up to date, more than150 chemical modifications are identified in nucleic acids. These chemical modifications do not change the sequence of DNA and RNA, but alter their structures and biochemical properties, and eventually control or regulate the spatial and temporal expression of genes. Elucidation of the functional roles of these modifications is vital to our understanding of living organisms. However, the modifications in DNA and RNA generally have extremely low abundance in vivo. Therefore, sensitive and specific detection methods are essential to decipher the functional roles of these modifications. Chemical derivatization in combination with mass spectrometry(MS) analysis has been proved to be a promising strategy to efficiently analyze these modifications in DNA and RNA. In the last several years, many chemical derivatization-MS-based analytical methods were established for the sensitive and effective analysis of nucleic acid modifications. In this review, we summarize the recent advances for deciphering modifications in DNA and RNA by chemical derivatization-MS analysis. We hope this review can stimulate the future studies of DNA and RNA modifications.

关键词： Mass spectrometry analysis Chemical derivatization DNA modification RNA modification

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on virtual coupling technology in rail transit train collision protection

引用

Transportation Safety and Environment 2024年第1期6卷 40-46页

作者： Gaosong Li Jinbai Zou Weijie Ma meng lan School of Railway Transportation Shanghai Institute of TechnologyShanghai 201418China Shanghai Metro First Operation Co. LtdShanghai 201418China

In the research on the new generation of intelligent rail transit system,the prevention of train collision accidents is still a *** coupling technology controls the running speed and interval distance of two or more trains cooperatively through Trainto-Train(T2T)direct communication *** aim is to form a coordinated logical system and jointly complete the train control and *** this paper,a virtual coupling train formation control method based on the model predictive control(MPC)framework is *** the establishment of the virtual coupling system,the construction of an MPC model and decoupling method,how to integrate virtual coupling technology into the rail transit train collision protection is *** safety and reliability of the system are calculated through fault tree and the method of constructing reliability *** research shows that if virtual coupling technology is used for train collision protection,the overall safety and reliability of the train control system is improved.

关键词： virtual coupling model predictive control collision protection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In-situ construction of novel sulfur-vacancy-rich Bi/Bi_(2)S_(3)/SnS_(2)Z-scheme heterostructure photocatalysts for efficient Cr(Ⅵ)reduction and nitrogen fixation

引用

Journal of Materials Science & Technology 2023年第36期167卷 237-247页

作者： meng lan Xiaoli Dong Nan Zheng Xiaoxin Zhang Yu Wang Xinxin Zhang School of Light Industry and Chemical Engineering Dalian Polytechnic UniversityDalian 116034China

Highly competent and economical photocatalysts are one of the most charming targets in environmental restoration and clean ***,a novel sulfur-vacancy-rich Bi/Bi_(2)S_(3)/SnS_(2)Z-scheme heterostruc-ture was constructed in situ and applied for the photoreduction Cr(VI)and nitrogen *** fab-ricated Bi/Bi_(2)S_(3)/SnS_(2)-2 exhibits the optimum photoreduction Cr(VI)performance with the efficiency of 94.5%within 15 min visible light *** remarkably enhanced catalytic efficiency derived from the synergistic effect of the construction of intimate contacted interface,abundant sulfur vacancy and surface plasmon resonance(SPR)effect of metal ***,the excellent photocatalytic nitrogen fix-ation property(96.4μmol g^(-1)h^(-1))was achieved by Bi/Bi_(2)S_(3)/SnS_(2)-2 under full solar illumination because sulfur vacancy could provide sufficient catalytic sites to accelerate the adsorption and nitrogen *** Z-scheme heterostructure was proposed to expound the photocatalytic *** work offers a new perspective on hierarchical heterostructure with plentiful vacancies for environmental remediation and energy development.

关键词： Sulfur-vacancy-rich Bi/Bi_(2)s_(3)/SnS_(2) Z-scheme heterostructure SPR effect Cr(VI)reduction Nitrogen fixation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Enhanced recovery after surgery strategy to shorten perioperative fasting in children undergoing non-gastrointestinal surgery:A prospective study

引用

World Journal of Clinical Cases 2022年第16期10卷 5287-5296页

作者： Yan Ying Hong-Zhen Xu meng-lan Han Department of General Surgery Children's Hospital of Zhejiang University School of MedicineHangzhou 310052Zhejiang ProvinceChina

BACKGROUND Enhanced recovery after surgery strategies are increasingly implemented to improve the management of surgical *** To evaluate the effects of new perioperative fasting protocols in children≥3 mo of age undergoing non-gastrointestinal *** This prospective pilot study included children≥3 mo of age undergoing nongastrointestinal surgery at the Children’s Hospital(Zhejiang University School of Medicine)from January 2020 to June *** children were divided into either a conventional group or an ERAS group according to whether they had been enrolled before or after the implementation of the new perioperative fasting *** children in the conventional group were fasted using conventional strategies,while those in the ERAS group were given individualized fasting protocols preoperatively(6-h fasting for infant formula/non-human milk/solids,4-h fasting for breast milk,and clear fluids allowed within 2 h of surgery)and postoperatively(food permitted from 1 h after surgery).Pre-operative and postoperative fasting times,pre-operative blood glucose,the incidence of postoperative thirst and hunger,the incidence of perioperative vomiting and aspiration,and the degree of satisfaction were *** The study included 303 patients(151 in the conventional group and 152 in the ERAS group).Compared with the conventional group,the ERAS group had a shorter pre-operative food fasting time[11.92(4.00,19.33)vs 13.00(6.00,20.28)h,P<0.001],shorter preoperative liquid fasting time[3.00(2.00,7.50)vs 12.00(3.00,20.28)h,P<0.001],higher preoperative blood glucose level[5.6(4.2,8.2)vs 5.1(4.0,7.4)mmol/L,P<0.001],lower incidence of thirst(74.5%vs 15.3%,P<0.001),shorter time to postoperative feeding[1.17(0.33,6.83)vs 6.00(5.40,9.20),P<0.001],and greater satisfaction[7(0,10)vs 8(5,10),P<0.001].No children experienced perioperative *** incidences of hunger,perioperative vomiting,and fever were not significantly different between the two groups.

关键词： Enhanced recovery after surgery Fasting Water deprivation Pre-operative period Postoperative period Intraoperative complications Postoperative complications

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Safe navigation of quadrotors with jerk limited trajectory

引用

Frontiers of Information Technology & Electronic Engineering 2019年第1期20卷 107-119页

作者： Shu-peng LAI meng-lu lan Ya-xuan LI Ben M.CHEN Department of Electrical and Computer Engineering National University of Singapore Graduate School for Integrative Science & Engineering National University of Singapore School of Control Science and Engineering Shandong University Department of Mechanical and Automation Engineering Chinese University of Hong Kong

Many aerial applications require unmanned aerial systems operate in safe zones because of the presence of obstacles or security regulations. It is a non-trivial task to generate a smooth trajectory satisfying both dynamic constraints and motion limits of the unmanned vehicles while being inside the safe zones. Then the task becomes even more challenging for real-time applications, for which computational efficiency is crucial. In this study, we present a safe flying corridor navigation method, which combines jerk limited trajectories with an efficient testing method to update the position setpoints in real time. Trajectories are generated online and incrementally with a cycle time smaller than 10 μs, which is exceptionally suitable for vehicles with limited onboard computational capability. Safe zones are represented with multiple interconnected bounding boxes which can be arbitrarily *** jerk limited trajectory generation algorithm has been extended to cover the cases with asymmetrical motion limits. The proposed method has been successfully tested and verified in flight simulations and actual experiments.

关键词： Quadrotor Unmanned aerial vehicle Motion planning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A novel loss-of-function variant in PNLDC1 inducing oligo-astheno-teratozoospermia and male infertility

引用

Asian Journal of Andrology 2023年第5期25卷 643-645页

作者： Si-Yi Zhao lan-lan meng Zhao-Li Du Yue-Qiu Tan Wen-Bin He Xiong Wang The First Clinical College of Guangzhou Medical University Guangzhou 511436China National Engineering and Research Center of Human Stem Cells and Institute of Reproductive and Stem Cell Engineering School of Basic Medical ScienceCentral South UniversityChangsha 410008China Reproductive and Genetic Hospital of CITIC-Xiangya and Clinical Research Center For Reproduction and Genetics in Hunan Province Changsha 410008China Yinfeng Gene Technology Co. Ltd.Jinan 250000China Reproductive Medicine Center Affiliated Yantai Yuhuangding Hospital of Qingdao UniversityYantai 264000China

Male infertility is a major reproductive disorder,which is clinically characterized by highly heterogeneous phenotypes of abnormal sperm count or *** date,five male patients with biallelic loss-of-function(LOF)variants of PARN-like ribonuclease domain-containing exonuclease 1(PNLDC1)have been reported to experience infertility with nonobstructive *** aim of this study was to identify the genetic cause of male infertility with oligo-astheno-teratozoospermia(OAT)in a patient from a Chinese Han ***-exome and Sanger sequencing analyses identified a homozygous LOF variant(NM_173516.2,c.l42C>T,***48Ter)in *** and eosin staining revealed that the spermatozoa of the patient with OAT had an irregular head phenotype,including microcephaly,head tapering,and ***,peanut agglutinin staining of the spermatozoa revealed a complete or partial loss of the ***,the disomy rate of chromosomes in the patient’s spermatozoa was significantly increased compared with that of a fertile control *** reported an LOF variant of the PNLDC1 gene responsible for OAT.

关键词： loss-of-function variant male infertility oligo-astheno-teratozoospermia PARN-like ribonuclease domain-containing exonuclease 1

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High value of controlled attenuation parameter predicts a poor antiviral response in patients with chronic hepatits B

引用

Hepatobiliary & Pancreatic Diseases International 2017年第4期16卷 370-374页

作者： Jing Chen meng-lan Wang Qin Long lang Bai Hong Tang Center of Infectious Diseases West China HospitalSichuan UniversityChengdu 610041China

BACKGROUND: Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing hepatic steatosis based on vibration-controlled transient elastography. The objective of this study was to investigate the effect of high value of CAP on antiviral therapy in patients with chronic hepatitis B (CHB). METHODS: Patients with CHB receiving enticavir for initial antiviral therapy were studied; they were divided into the high CAP group and normal CAP group at baseline according to the CAP values. The effect of the antiviral therapy between the two groups were compared at week 12, 24 and 48. Patients with high CAP value at baseline were divided into three subgroups, mild, moderate and severe elevation; the therapeutic response were compared among patients with normal CAP and subgroups of patients with elevated CAP. RESULTS: A total of 153 patients were enrolled. Among them, 63 were in the high CAP group and 90 in the normal CAP group. Patients with high CAP had lower rates of ALT normalization and HBV DNA clearance in response to antiviral therapy compared with those with normal CAP at week 12, 24 and 48. Further analysis showed that the rate of ALT normalization in patients with mildly and moderately elevated CAP were significant lower than those with normal CAP at week 12 and 24; while the difference was not significant between the patients with normal CAP and those with severely elevated CAP. The rate of HBV DNA clearance was significantly lower in patients with severely elevated CAP compared with those with normal CAP at week 12, 24 and 48. CONCLUSION: CHB patients with high CAP had poor response to antiviral therapy.

关键词： controlled attenuation parameter chronic hepatitis B treatment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of spudcan-footprint interaction in a single soil with nonlinear FEM

引用

Petroleum Science 2015年第1期12卷 148-156页

作者： Dong-Feng Mao Ming-Hui Zhang Yang Yu meng-lan Duan Jun Zhao College of Mechanical and Transportation Engineering China University of Petroleum

The footprints that remain on the seabed after offshore jack-up platforms completed operations and moved out provide a significant risk for any futurej ack-up installation at that site. Detrimental horizontal and/or rotational loads will be induced on the base cone of the jack-up platform leg （spudcan） in the preloading process where only vertical loads are normally expected. However, there are no specific guidelines on design of spudcan re-installation very close to or partially overlapping existing footprints. This paper presents a rational design approach for assessing spudcan-footprint interaction and the failure process of foundation in a single layer based on nonlinear finite element method. The rela- tionship between the distance between the spudcan and the footprint and the horizontal sliding force has been obtained. Comparisons of simulation and experimental results show that the model in this paper can deal well with the combined problems of sliding friction contact, fluid-solid coupling, and convergence difficulty. The analytical results may be useful to jack-up installation workovers close to existing footprints.

关键词： Jack-up Existing footprint Spudcan-footprint interaction Numerical simulation Nonlinearity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：