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   251666篇
  免费   6946篇
  国内免费   255篇
耳鼻咽喉   2024篇
儿科学   8600篇
妇产科学   4060篇
基础医学   26889篇
口腔科学   2365篇
临床医学   20419篇
内科学   47530篇
皮肤病学   1528篇
神经病学   23843篇
特种医学   11812篇
外科学   41066篇
综合类   3183篇
一般理论   91篇
预防医学   23727篇
眼科学   4669篇
药学   14675篇
中国医学   716篇
肿瘤学   21670篇
  2023年   667篇
  2022年   1040篇
  2021年   2415篇
  2020年   1364篇
  2019年   2217篇
  2018年   24114篇
  2017年   18858篇
  2016年   21111篇
  2015年   3079篇
  2014年   3964篇
  2013年   4771篇
  2012年   13321篇
  2011年   27379篇
  2010年   22159篇
  2009年   14587篇
  2008年   24581篇
  2007年   26967篇
  2006年   5663篇
  2005年   7220篇
  2004年   7927篇
  2003年   8492篇
  2002年   6266篇
  2001年   863篇
  2000年   815篇
  1999年   728篇
  1998年   987篇
  1997年   782篇
  1996年   562篇
  1995年   522篇
  1994年   494篇
  1993年   450篇
  1992年   298篇
  1991年   291篇
  1990年   307篇
  1989年   241篇
  1988年   216篇
  1987年   178篇
  1986年   163篇
  1985年   181篇
  1984年   207篇
  1983年   177篇
  1982年   263篇
  1981年   237篇
  1980年   212篇
  1979年   104篇
  1978年   129篇
  1977年   105篇
  1976年   84篇
  1975年   66篇
  1974年   69篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Background A high Mandard score implies a non-response to chemotherapy in oesophageal adenocarcinoma. However, some patients exhibit tumour volume reduction and a nodal response despite a high score. This study examines survival and recurrence patterns in these patients.Methods Clinicopathological factors were analysed using multivariable Cox regression assessing time to death and recurrence. Computed tomography-estimated tumour volume change was examined in a subgroup of consecutive patients.Results Five hundred and fifty-five patients were included. Median survival was 55 months (Mandard 1–3) and 21 months (Mandard 4 and 5). In the Mandard 4 and 5 group (332 patients), comparison between complete nodal responders and persistent nodal disease showed improved survival (90 vs 18 months), recurrence rates (locoregional 14.75 vs 28.74%, systemic 24.59 vs 48.42%) and circumferential resection margin positivity (22.95 vs 68.11%). Complete nodal response independently predicted improved survival (hazard ratio 0.34 (0.16–0.74). Post-chemotherapy tumour volume reduction was greater in patients with a complete nodal response (−16.3 vs −7.7 cm3, p = 0.033) with no significant difference between Mandard groups.Conclusion Patients with a complete nodal response to chemotherapy have significantly improved outcomes despite a poor Mandard score. High Mandard score does not correspond with a non-response to chemotherapy in all cases and patients with nodal downstaging may still benefit from adjuvant chemotherapy.Subject terms: Oesophageal cancer, Surgical oncology  相似文献   
13.
Arthroscopic acromioclavicular joint excision is a commonly performed but technically demanding procedure. Incomplete excision can leave residual symptoms. We present a simple, reproducible technique ensuring satisfactory excision of the joint.  相似文献   
14.
Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets.  相似文献   
15.
This paper takes a somewhat slant perspective on flourishing and care in the context of suffering, death and dying, arguing that care in this context consists principally of ‘acts of work and courage that enable flourishing’. Starting with the perception that individuals, society and health care professionals have become dulled to death and the process of dying in Western advanced health systems, it suggests that for flourishing to occur, both of these aspects of life need to be faced more directly. The last days of life need to be ‘undulled’. Reflections upon the experiences of the author as carer and daughter in the face of her mother’s experience of death are used as basis for making suggestions about how care systems and professionals might better assist people in dealing with ‘the most grown up thing’ humans ever do, which is to die.  相似文献   
16.
17.
Coronavirus disease 2019 (COVID-19) has resulted in many challenges in patient care, especially among high-risk populations such as heart transplant recipients. Patients with heart transplant experience a significantly higher mortality rate with COVID-19 infection, and management is based on extrapolation from clinical trials done on nontransplant patients and from clinical experience. Here we report 4 cases of patients with heart transplant who presented with COVID-19 infection in late 2020. Patients presented with symptoms similar to those seen in the general population. All 4 patients were admitted to the hospital, and they were all treated with dexamethasone. In addition, 2 patients received remdesivir. Immunosuppressive medications were adjusted to maintain adequate levels of immunosuppression but at the same time allow for an adequate immune response against the infection. All patients were discharged alive from the hospital. We then performed a literature review on studies that included heart transplant patients who developed the infection and developed suggestions for a standardized management approach, which we share in this article.  相似文献   
18.
Background: Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease. Methods: Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function. Results: All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation. Conclusions: Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.  相似文献   
19.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
20.
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