全文获取类型
收费全文 | 2609篇 |
免费 | 152篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 133篇 |
妇产科学 | 24篇 |
基础医学 | 309篇 |
口腔科学 | 8篇 |
临床医学 | 194篇 |
内科学 | 784篇 |
皮肤病学 | 15篇 |
神经病学 | 217篇 |
特种医学 | 41篇 |
外国民族医学 | 2篇 |
外科学 | 428篇 |
综合类 | 3篇 |
预防医学 | 108篇 |
眼科学 | 196篇 |
药学 | 169篇 |
中国医学 | 1篇 |
肿瘤学 | 121篇 |
出版年
2022年 | 20篇 |
2021年 | 44篇 |
2020年 | 23篇 |
2019年 | 44篇 |
2018年 | 65篇 |
2017年 | 38篇 |
2016年 | 28篇 |
2015年 | 25篇 |
2014年 | 51篇 |
2013年 | 93篇 |
2012年 | 113篇 |
2011年 | 118篇 |
2010年 | 74篇 |
2009年 | 67篇 |
2008年 | 112篇 |
2007年 | 156篇 |
2006年 | 150篇 |
2005年 | 135篇 |
2004年 | 109篇 |
2003年 | 101篇 |
2002年 | 117篇 |
2001年 | 95篇 |
2000年 | 114篇 |
1999年 | 91篇 |
1998年 | 30篇 |
1997年 | 17篇 |
1996年 | 23篇 |
1995年 | 15篇 |
1994年 | 14篇 |
1992年 | 59篇 |
1991年 | 42篇 |
1990年 | 51篇 |
1989年 | 55篇 |
1988年 | 29篇 |
1987年 | 49篇 |
1986年 | 46篇 |
1985年 | 35篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1979年 | 18篇 |
1975年 | 21篇 |
1974年 | 21篇 |
1973年 | 12篇 |
1972年 | 15篇 |
1971年 | 13篇 |
1970年 | 21篇 |
1969年 | 16篇 |
1967年 | 16篇 |
1966年 | 18篇 |
1965年 | 21篇 |
排序方式: 共有2779条查询结果,搜索用时 15 毫秒
81.
Rewritable digital data storage in live cells via engineered control of recombination directionality
Bonnet J Subsoontorn P Endy D 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(23):8884-8889
The use of synthetic biological systems in research, healthcare, and manufacturing often requires autonomous history-dependent behavior and therefore some form of engineered biological memory. For example, the study or reprogramming of aging, cancer, or development would benefit from genetically encoded counters capable of recording up to several hundred cell division or differentiation events. Although genetic material itself provides a natural data storage medium, tools that allow researchers to reliably and reversibly write information to DNA in vivo are lacking. Here, we demonstrate a rewriteable recombinase addressable data (RAD) module that reliably stores digital information within a chromosome. RAD modules use serine integrase and excisionase functions adapted from bacteriophage to invert and restore specific DNA sequences. Our core RAD memory element is capable of passive information storage in the absence of heterologous gene expression for over 100 cell divisions and can be switched repeatedly without performance degradation, as is required to support combinatorial data storage. We also demonstrate how programmed stochasticity in RAD system performance arising from bidirectional recombination can be achieved and tuned by varying the synthesis and degradation rates of recombinase proteins. The serine recombinase functions used here do not require cell-specific cofactors and should be useful in extending computing and control methods to the study and engineering of many biological systems. 相似文献
82.
83.
Oliv Eidam Chiara Romagnoli Guillaume Dalmasso Sarah Barelier Emilia Caselli Richard Bonnet Brian K. Shoichet Fabio Prati 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(43):17448-17453
Fragment-based design was used to guide derivatization of a lead series of β-lactamase inhibitors that had heretofore resisted optimization for in vivo activity. X-ray structures of fragments overlaid with the lead suggested new, unanticipated functionality and points of attachment. Synthesis of three derivatives improved affinity over 20-fold and improved efficacy in cell culture. Crystal structures were consistent with the fragment-based design, enabling further optimization to a Ki of 50 pM, a 500-fold improvement that required the synthesis of only six derivatives. One of these, compound 5, was tested in mice. Whereas cefotaxime alone failed to cure mice infected with β-lactamase-expressing Escherichia coli, 65% were cleared of infection when treated with a cefotaxime:5 combination. Fragment complexes offer a path around design hurdles, even for advanced molecules; the series described here may provide leads to overcome β-lactamase-based resistance, a key clinical challenge. 相似文献
84.
85.
Terrier B Krastinova E Marie I Launay D Lacraz A Belenotti P de Saint-Martin L Quemeneur T Huart A Bonnet F Le Guenno G Kahn JE Hinschberger O Rullier P Diot E Lazaro E Bridoux F Zénone T Carrat F Hermine O Léger JM Mariette X Senet P Plaisier E Cacoub P 《Blood》2012,119(25):5996-6004
Data on the clinical spectrum and therapeutic management of noninfectious mixed cryoglobulinemia vasculitis (CryoVas) in the era of hepatitis C virus screening are lacking. We analyzed data from 242 patients with noninfectious mixed CryoVas included in the French multicenter CryoVas survey. Baseline manifestations were purpura (75%), peripheral neuropathy (52%), arthralgia or arthritis (44%), glomerulonephritis (35%), cutaneous ulcers (16%), and cutaneous necrosis (14%). A connective tissue disease was diagnosed in 30% and B-cell non-Hodgkin lymphoma in 22%, whereas the CryoVas was considered to be essential in 48%. With the use of Cox-marginal structural models, rituximab plus corticosteroids showed the greater therapeutic efficacy compared with corticosteroids alone and alkylating agents plus corticosteroids to achieve complete clinical, renal, and immunologic responses and a prednisone dosage < 10 mg/d at 6 months. However, this regimen was also associated with severe infections, particularly when high doses of corticosteroids were used, whereas death rates did not differ between the therapeutic regimens. The role of each of these strategies remains to be defined in well-designed randomized controlled trials. 相似文献
86.
87.
88.
89.
M. Geneviève F. Bonnet C. Michaux C.-E. Geffroy M.-A. Vandenhende C. Combe P. Morlat 《La Revue de médecine interne / fondée ... par la Société nationale francaise de médecine interne》2012
We report a 24-year-old woman who presented with a nephrotic syndrome as the revealing manifestation of systemic lupus erythematosus (SLE) and an associated hypogammaglobulinemia related to a common variable immunodeficiency (CVID). Outcome of SLE was favourable with intravenous immunoglobulin treatment solely. Relationships between SLE and CVID are discussed. 相似文献
90.
J.-P. Avaro N. Biance P.-H. Savoie T. Peycru P.-M. Bonnet P. Balandraud 《Acta chirurgica Belgica》2013,113(6):744-746
The authors report an isolated common femoral artery injury caused by blunt trauma with dissection and secondary ischaemia.A 21-year-old man was admitted to hospital after being stabbed during acute alcoholic intoxication. He presented with a stab wound on the left leg and blunt trauma in the right groin. The surgical exploration of the left-sided wound did not disclose any vascular injury. After a 12-hour period of observation, the patient was discharged. Six hours later, he came back with severe ischaemia on the right leg caused by a femoral artery dissection. The patient underwent surgical revascularization, and fully recovered.Isolated artery blunt trauma is a rare event. In this observation, the absence of early symptoms resulted in delayed diagnosis. 相似文献