首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1552篇
  免费   193篇
  国内免费   324篇
  2024年   8篇
  2023年   66篇
  2022年   85篇
  2021年   92篇
  2020年   111篇
  2019年   118篇
  2018年   86篇
  2017年   81篇
  2016年   76篇
  2015年   85篇
  2014年   111篇
  2013年   138篇
  2012年   114篇
  2011年   108篇
  2010年   61篇
  2009年   86篇
  2008年   70篇
  2007年   65篇
  2006年   83篇
  2005年   74篇
  2004年   50篇
  2003年   58篇
  2002年   43篇
  2001年   46篇
  2000年   28篇
  1999年   31篇
  1998年   18篇
  1997年   14篇
  1996年   11篇
  1995年   7篇
  1994年   7篇
  1993年   8篇
  1992年   2篇
  1991年   3篇
  1990年   5篇
  1989年   2篇
  1988年   4篇
  1987年   3篇
  1985年   3篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1979年   2篇
  1950年   1篇
排序方式: 共有2069条查询结果,搜索用时 281 毫秒
51.
针对卫生行业对高职医学生物技术专业人才需求,对接企业就业岗位群,设置微生物技术"学习领域"课程,开发设计来源于企业生产或服务实践的以工作过程为导向的"学习情境"教学单元。强化职业导向,开展理论实践一体化项目教学及云班课互动教学改革。采取多元化考核形式,以产品或项目成果为指引,给学生提供感知和体验工作过程的机会。经过多个学习情境项目教学的长期强化训练,学生积累了适应未来岗位的综合技能和素质。  相似文献   
52.
陈向东 《微生物学通报》2020,47(4):1001-1003
突如其来的新型冠状病毒肺炎疫情使得网上在线教学成为这段时间的唯一教学方式。这一方面给高校的广大师生提出了新的挑战,但同时也给近年来一直进行的高等教育开放式教育教学改革发展潮流按下了加速键。《微生物学通报》以"第十七届全国微生物学教学和科研及成果产业化研讨会"为契机邀稿组织出版的这期"高等院校教学主题刊",很好地反映了近年来在开放式教育形势下我国微生物学教学改革与人才培养的最新进展和发展态势,其中也有文章介绍了疫情期间选择和使用线上教学技术的经验。期望该主题刊的出版有助于进一步促进广大微生物学教师强化互联网意识,打造"互联网+"思维,重塑课堂教学形态,通过广大教师间的教改经验交流与合作,进一步促进我国微生物学课程建设水平与教学质量的全面提升。  相似文献   
53.
好氧反硝化生物脱氮技术的研究进展   总被引:4,自引:1,他引:3  
好氧反硝化生物脱氮技术自提出以来,凭借能实现同步硝化反硝化、节省基建投资及运行费用等诸多优点,受到国内外环境领域学者的广泛关注。本文首先总结了近年来好氧反硝化菌种的筛选分离情况,以及环境因子对好氧反硝化菌脱氮效能的影响,包括溶解氧(dissolved oxygen,DO)、碳氮比(C/N)、温度等。然后深入探讨了好氧反硝化生物脱氮技术的原理,好氧反硝化过程中的关键功能基因及酶,同时介绍了分子生物技术在好氧反硝化研究过程中的应用,以及好氧反硝化生物脱氮技术在实际应用方面的研究现状。最后,基于目前的研究瓶颈问题,对未来好氧反硝化生物脱氮技术的研究方向提出了科学展望。  相似文献   
54.
Abstract

Gastric cancer (GC) is the second leading cause of cancer-related deaths in the world. Due to the shortage of adequate symptoms in the early stages, it is diagnosed when the tumor has spread to distant organs. Early recognition of GC enhances the chance of successful treatment. Molecular mechanisms of GC are still poorly understood. LncRNAs are emerging as new players in cancer in both oncogene and tumor suppressor roles. High-throughput technologies such as RNA-Seq, have revealed thousands of lncRNAs which are dysregulated in GC. In this study, we retrieved lncRNAs obtained by High-throughput technologies from OncoLnc database. Consequently, retrieved lncRNAs were compared in literature-based databases including PubMed. As a result, two lists, including experimentally validated lncRNAs and predicted lncRNAs were provided. We found 43 predicted lncRNAs that had not been experimentally validated in GC, so far. Further Bioinformatics analyses were performed to obtain the expression profile of predicted lncRNAs in tumor and normal tissues. Also, the roles and targets of predicted lncRNAs in GC were identified by related databases. Finally, using the GEPIA database was reviewed the significant relationship of predicted lncRNAs with the survival of GC patients. By recognizing the lncRNAs involved in initiation and progression of GC, they may be considered as potential biomarkers in the GC early diagnosis or targeted treatment and lead to novel therapeutic strategies.

Communicated by Ramaswamy H. Sarma  相似文献   
55.
56.
Dissolved carbon dioxide (dCO2) is a well-known critical parameter in bioprocesses due to its significant impact on cell metabolism and on product quality attributes. Processes run at small-scale faces many challenges due to limited options for modular sensors for online monitoring and control. Traditional sensors are bulky, costly, and invasive in nature and do not fit in small-scale systems. In this study, we present the implementation of a novel, rate-based technique for real-time monitoring of dCO2 in bioprocesses. A silicone sampling probe that allows the diffusion of CO2 through its wall was inserted inside a shake flask/bioreactor and then flushed with air to remove the CO2 that had diffused into the probe from the culture broth (sensor was calibrated using air as zero-point calibration). The gas inside the probe was then allowed to recirculate through gas-impermeable tubing to a CO2 monitor. We have shown that by measuring the initial diffusion rate of CO2 into the sampling probe we were able to determine the partial pressure of the dCO2 in the culture. This technique can be readily automated, and measurements can be made in minutes. Demonstration experiments conducted with baker's yeast and Yarrowia lipolytica yeast cells in both shake flasks and mini bioreactors showed that it can monitor dCO2 in real-time. Using the proposed sensor, we successfully implemented a dCO2-based control scheme, which resulted in significant improvement in process performance.  相似文献   
57.

Background

Campylobacter jejuni is an important food-borne and zoonotic pathogen with a worldwide distribution. Humans and chickens are hosts of this pathogen. At present, there is no ideal vaccine for controlling human campylobacteriosis or the carriage of C. jejuni by chickens. Bacterial in vivo-induced antigens are useful as potential vaccine candidates and biomarkers of virulence.

Methods

In this study, we developed a novel systematic immunoproteomics approach to identify in vivo-induced antigens among the total cell proteins of C. jejuni using pre-adsorbed sera from patients infected with C. jejuni.

Results

Overall, 14 immunoreactive spots were probed on a PVDF membrane using pre-adsorbed human sera against C. jejuni. Then, we excised these protein spots from a duplicate gel and identified using MALDI–TOF MS. In total, 14 in vivo-induced antigens were identified using PMF and BLAST analysis. The identified proteins include CadF (CadF-1 and CadF-2), CheW, TufB, DnaK, MetK, LpxB, HslU, DmsA, PorA, ProS, CJBH_0976, CSU_0396 and hypothetical protein cje135_05017. Real-time RT-PCR was performed on 9 genes to compare their expression levels in vivo and in vitro. The data showed that 8 of the 9 analyzed genes were significantly upregulated in vivo relative to in vitro.

Conclusion

We successfully developed a novel immunoproteomics method for identifying in vivo-induced Campylobacter jejuni antigens by using pre-adsorbed sera from infected patients.

General significance

This new analysis method may prove to be useful for identifying in vivo-induced antigens within any host infected by bacteria and will contribute to the development of new subunit vaccines.  相似文献   
58.
Herein, we describe a case of an infertile man detected in postnatal diagnosis with FISH characterization and array-CGH used for genome-wide screening which allowed the identification of a complex rearrangement involving sex chromosomes, apparently without severe phenotypic consequences. The deletion detected in our patient has been compared with previously reported cases leading us to propose a hypothetical diagnostic algorithm that would be useful in similar clinical situations, with imperative multi disciplinary approach integrated with genetic counseling. Our patient, uniquely of reproductive age, is one of six reported cases of duplication of Xp22.3 (~ 8.4 Mb) segment and contemporary deletion of Yq (~ 42.9 Mb) with final karyotype as follows:
46,X,der(Y),t(X;Y)(Ypter → Yq11.221::Xp22.33 → Xpter).ish der(Y) (Yptel+,Ycen+,RP11-529I21+,RP11-506M9-Yqtel −,Xptel +). arrXp22.33p22.31(702–8,395,963, 8,408,289x1), Yq11.221q12 (14,569,317x1, 14,587,321–57,440,839x0)  相似文献   
59.
60.
Platinum-based anti-cancer agents have been used for many years to treat many different types of cancer. However, the efficacy of these drugs is limited by serious side effects. One of the strategies to reduce the side effects is encapsulation of the drug in a lipid formulation. Recently, we discovered a novel method for the efficient encapsulation of cisplatin in a lipid formulation. The method is unique in that it does not generate conventional liposomes but nanocapsules: small aggregates of solid cisplatin covered by a lipid bilayer. Also carboplatin, a cisplatin-derived anti-cancer drug with different chemical properties, can be efficiently encapsulated by a similar method. The encapsulation in nanocapsules dramatically improves the in vitro cytotoxicity of the platinum drugs. Our results hold the promise that the nanocapsule technology could prove successful in the efficient encapsulation of many other (platinum-based) drugs, and thereby improve their therapeutic index and profile in vivo.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号