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   201015篇
  免费   2419篇
  国内免费   259篇
耳鼻咽喉   1355篇
儿科学   7124篇
妇产科学   3559篇
基础医学   19082篇
口腔科学   2183篇
临床医学   14137篇
内科学   38316篇
皮肤病学   1000篇
神经病学   18625篇
特种医学   9811篇
外科学   33569篇
综合类   2356篇
一般理论   5篇
预防医学   19056篇
眼科学   3233篇
药学   10975篇
中国医学   680篇
肿瘤学   18627篇
  2024年   32篇
  2023年   291篇
  2022年   606篇
  2021年   1028篇
  2020年   587篇
  2019年   847篇
  2018年   22714篇
  2017年   17932篇
  2016年   20186篇
  2015年   1764篇
  2014年   1969篇
  2013年   2194篇
  2012年   9087篇
  2011年   22955篇
  2010年   19916篇
  2009年   12586篇
  2008年   21162篇
  2007年   23306篇
  2006年   2147篇
  2005年   3764篇
  2004年   4870篇
  2003年   5604篇
  2002年   3627篇
  2001年   374篇
  2000年   514篇
  1999年   316篇
  1998年   397篇
  1997年   359篇
  1996年   239篇
  1995年   245篇
  1994年   215篇
  1993年   170篇
  1992年   123篇
  1991年   135篇
  1990年   181篇
  1989年   118篇
  1988年   88篇
  1987年   71篇
  1986年   63篇
  1985年   64篇
  1984年   52篇
  1983年   52篇
  1982年   72篇
  1981年   29篇
  1980年   66篇
  1974年   30篇
  1938年   62篇
  1934年   32篇
  1932年   59篇
  1930年   47篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Introduction  Creation of the bladder flap, i.e., dissecting the urinary bladder from the lower segment of the uterus is a standard part of cesarean section (CS). However, it is yet to be established whether the formation of bladder flap is advantageous. Review of literature  Pelosi and Ortega in 1994 introduced a new minimally invasive technique of CS, which included the omission of bladder dissection together with other modifications. Omission of the bladder flap provides short-term benefits such as reduction of operating time and incision-delivery interval, wound infection, reduced blood loss and analgesic requirement. In addition, it is associated with good long-term outcomes with regards to adhesion formation. Conclusion  Further large-scale controlled randomized clinical trials are needed to investigate the safety of this technique with respect to in deeply engaged head, preterm, subsequent pregnancies and trial of labor and also to determine the future role of this technique that will contribute to advancement and popularity of this technique amongst obstetricians.  相似文献   
992.
993.
994.
Purpose  Enhanced recovery programs aim to expedite gut function after elective colorectal surgery. Early oral feeding simulates gut function but is not always feasible. Gum chewing, a form of sham feed, is an alternative. We assessed current evidence for gum chewing and gut function. Study design  All randomized controlled trials (RCTs) between 1990 and 2008 comparing gum chewing with controls/placebo were analyzed irrespective of language, blinding, or publication bias. The Jadad scale was used to assess study quality. Endpoints were time to flatus/feces, postoperative complications, and hospital stay. Random and fixed models were employed to aggregate study endpoints and assess heterogeneity. Results  Six RCTs containing 256 patients were included. Significant heterogeneity was identified and random effects model was employed. Heterogeneity may be explained through variations in delivery of surgical care. Significant reductions in the time to flatus and time to feces were identified but no significant difference in hospital or in-hospital postoperative complications were found. Conclusions  Gum chewing significantly reduced time to flatus and feces; however, hospital stay and postoperative complications were not reduced. Significant study heterogeneity means that these results should be interpreted with caution. Presentation to European Society of Coloproctology Annual Scientific Meeting Malta September 2007 Presentation to West of Scotland Surgical Association Annual Scientific Meeting October 2007  相似文献   
995.
996.
We characterized 168 junctional regions of T-cell receptor delta (TCRD) rearrangements from 116 children with acute lymphoblastic leukemia (ALL) (101 with precursor B-cell ALL, 15 with T-cell ALL). Application of 101 allele-specific oligonucleotide (ASO) probes representing 85 Vdelta2Ddelta3, 10 Ddelta2Ddelta3, 3 Vdelta1Jdelta1, 1 Vdelta3Jdelta1, and 2 Ddelta2Jdelta1 junctions for the detection of minimal residual disease (MRD) revealed detection levels of 10(-4) to 10(-6) leukemia cells in the vast majority of cases (93 of 101). Of interest was that neither the N, D, P (nontemplated, diversity, palindromic) content and length of the junctional regions nor the number of nucleotides deleted from the flanking V, D, or J (variable, diversity, joining) elements correlated with the sensitivity of ASO probes. These data indicated that in ALL TCRD rearrangements can serve as suitable tools for the detection of MRD irrespective of the specific composition of the junctional region.  相似文献   
997.
The clinical application of portal vein embolization (PVE) has contributed to improving the postoperative outcome of hilar cholangiocarcinoma. The enlarged nonembolized lobe after PVE protects the patient from postoperative hepatic failure, due to the increased functional reserve, and shortens the hospital stay. Although numerous reports have shown beneficial effects of PVE on postoperative outcome after extended hepatectomy, no randomized controlled study has been performed so far. It is urgent to establish a “gold standard” of PVE, because the indications, approach to the portal vein, types of embolic materials, and methods used to evaluate the function of the future liver remnant are variable among institutions. The indications and procedures of PVE for hilar cholangiocarcinoma may be different from those for hepatocellular carcinoma or colorectal metastasis, because, in many patients with hilar cholangiocarcinoma, biliary cancer is associated with biliary obstruction and cholangitis. This review article summarizes the contribution of PVE to the outcome of postoperative management in patients with hilar cholangiocarcinoma needing extended hepatectomy. We also describe our PVE procedure, which has been established from our experience of more than 240 cases of biliary cancer. Furthermore, the drawbacks of PVE, which may reduce the pool of candidates for surgery, are also discussed.  相似文献   
998.
Chronic synovitis, unresponsive to systemic medical therapy including agents, anti-inflammatory drugs and remission-inducing agents, and intra-articular administration of corticosteroids can be treated with surgical, chemical and radiation synovectomy. We reported a case of a 23 years old male. Skin radiation necrosis (4 x 5 cm) developed after an injection of Yttrium-90 (Y-90). Full-thickness skin graft had been applied but we were not able to succeed. Skin radiation necrosis was treated with Limberg's flap. As a result we recommend flap surgery instead of skin graft in skin radiation necrosis.  相似文献   
999.
Severe constant and intermittent knee pain are associated with “unacceptable” symptoms in older adults with osteoarthritis (OA) [22]. We hypothesized that constant and intermittent pain would be independently related to physical function, with intermittent knee pain being a better predictor of future declines in physical function in early symptomatic knee OA. This study included men (n?=?189) and women (n?=?133) with radiographic, unilateral knee OA, observed using data from the Osteoarthritis Initiative (OAI). Pain types were measured using the Intermittent and Constant Osteoarthritis Pain (ICOAP) scale. Physical function was measured using the Western Ontario and McMaster Universities Arthritis Index (WOMAC-PF) and Knee Injury and Osteoarthritis Outcome Score (KOOS-FSR) and physical performance tests. High baseline intermittent (B?=?0.277; p?=?0.001) and constant (B?=?0.252; p?=?0.001) knee pain were related to poor WOMAC-PF. Increased constant (B?=?0.484; p?=?0.001) and intermittent (B?=?0.104; p?=?0.040) pain were related to 2-year decreased WOMAC-PF. High baseline intermittent knee pain predicted poor KOOS-FSR at year 2 (B?=??0.357; p?=?0.016). Increased constant pain was related to decreased chair stand test performance over 2 years in women (B?=?0.077; p?=?0.001). High baseline intermittent pain was related to poor performance on repeated chair stands (B?=?0.035; p?=?0.021), while baseline constant pain was related to poor 400-m walk performance in women (B?=?0.636; p?=?0.047). Intermittent and constant knee pain were independent factors in self-perceived physical function and were important predictors of future limitations in physical function. Identifying intermittent and constant pain in early symptomatic OA may allow patients to adopt strategies to prevent worsening pain and future declines in physical function.  相似文献   
1000.
Several classification schemes have been developed for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), with actual debate focusing on their clinical and prognostic performance. Sixty-two patients with renal biopsy-proven AAV from a single center in Mexico City diagnosed between 2004 and 2013 were analyzed and classified under clinical (granulomatosis with polyangiitis [GPA], microscopic polyangiitis [MPA], renal limited vasculitis [RLV]), serological (proteinase 3 anti-neutrophil cytoplasmic antibodies [PR3-ANCA], myeloperoxidase anti-neutrophil cytoplasmic antibodies [MPO-ANCA], ANCA negative), and histopathological (focal, crescenteric, mixed-type, sclerosing) categories. Clinical presentation parameters were compared at baseline between classification groups, and the predictive value of different classification categories for disease and renal remission, relapse, renal, and patient survival was analyzed. Serological classification predicted relapse rate (PR3-ANCA hazard ratio for relapse 2.93, 1.20–7.17, p?=?0.019). There were no differences in disease or renal remission, renal, or patient survival between clinical and serological categories. Histopathological classification predicted response to therapy, with a poorer renal remission rate for sclerosing group and those with less than 25 % normal glomeruli; in addition, it adequately delimited 24-month glomerular filtration rate (eGFR) evolution, but it did not predict renal nor patient survival. On multivariate models, renal replacement therapy (RRT) requirement (HR 8.07, CI 1.75–37.4, p?=?0.008) and proteinuria (HR 1.49, CI 1.03–2.14, p?=?0.034) at presentation predicted renal survival, while age (HR 1.10, CI 1.01–1.21, p?=?0.041) and infective events during the induction phase (HR 4.72, 1.01–22.1, p?=?0.049) negatively influenced patient survival. At present, ANCA-based serological classification may predict AAV relapses, but neither clinical nor serological categories predict renal or patient survival. Age, renal function and proteinuria at presentation, histopathology, and infectious complications constitute the main outcome predictors and should be considered for individualized management.  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