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   2098篇
  免费   115篇
  国内免费   24篇
耳鼻咽喉   13篇
儿科学   173篇
妇产科学   30篇
基础医学   246篇
口腔科学   52篇
临床医学   210篇
内科学   468篇
皮肤病学   26篇
神经病学   79篇
特种医学   501篇
外科学   132篇
综合类   32篇
预防医学   73篇
眼科学   15篇
药学   80篇
中国医学   3篇
肿瘤学   104篇
  2022年   10篇
  2021年   16篇
  2020年   18篇
  2019年   17篇
  2018年   26篇
  2017年   14篇
  2016年   36篇
  2015年   36篇
  2014年   37篇
  2013年   72篇
  2012年   35篇
  2011年   50篇
  2010年   87篇
  2009年   66篇
  2008年   57篇
  2007年   43篇
  2006年   56篇
  2005年   32篇
  2004年   25篇
  2003年   27篇
  2002年   34篇
  2001年   29篇
  2000年   38篇
  1999年   36篇
  1998年   136篇
  1997年   125篇
  1996年   130篇
  1995年   95篇
  1994年   82篇
  1993年   86篇
  1992年   34篇
  1991年   29篇
  1990年   28篇
  1989年   64篇
  1988年   56篇
  1987年   61篇
  1986年   58篇
  1985年   60篇
  1984年   28篇
  1983年   35篇
  1982年   36篇
  1981年   21篇
  1980年   38篇
  1979年   18篇
  1978年   16篇
  1977年   22篇
  1976年   27篇
  1975年   26篇
  1971年   4篇
  1967年   4篇
排序方式: 共有2237条查询结果,搜索用时 15 毫秒
101.
The vasa vasorum and angioplasty   总被引:2,自引:0,他引:2  
Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances.  相似文献   
102.
Survey of reproductive health among female MR workers   总被引:5,自引:1,他引:5  
  相似文献   
103.
Migraine is a common, disabling disorder associated with considerable personal and societal burden. Current guidelines recommend triptans for the acute treatment of migraine unlikely to respond to less effective therapies. Rizatriptan is a second-generation triptan available in tablet or orally disintegrating tablet (wafer) formulations that offers several advantages over other members of its class. Rizatriptan is rapidly absorbed from the gastrointestinal tract and achieves maximum plasma concentrations more quickly than other triptans, providing rapid pain relief. Clinical trials have shown that rizatriptan is at least as effective or superior to other oral migraine-specific agents in the acute treatment of migraine, and has more consistent long-term efficacy across multiple migraine attacks. Rizatriptan has a favorable tolerability profile, and patients have reported greater satisfaction and a preference for rizatriptan over other migraine-specific agents. Improvements in quality of life reported with rizatriptan are consistent with its favorable efficacy and tolerability profiles. Notably, multi-attribute decision models that combine clinical data with patient- and physician-reported treatment preferences have identified rizatriptan as one of three triptans closest to a hypothetical “ideal”. The efficacy and tolerability of rizatriptan for the acute treatment of migraine have thus been well established.  相似文献   
104.
Allogeneic bone marrow transplantation (BMT) for advanced acute leukemia is associated with a high risk of relapse. It is postulated that interleukin-2 (IL-2) administered after BMT might induce or amplify a graft-versus-leukemia effect and thereby reduce the relapse rate. To identify an IL-2 regimen for testing this hypothesis, a phase I trial of IL-2 (Roche) was performed in children in complete remission (CR) without active graft-versus-host disease (GVHD) off immunosuppressive agents after unmodified allogeneic matched-sibling BMT for acute leukemia beyond first remission. Beginning a median of 68 days after BMT, 17 patients received escalating doses of induction IL-2 (0.9, 3.0, or 6.0 x 10(6) IU/m2/d representing levels I, II, and III) for 5 days by continuous intravenous infusion (CIV). After 6 days of rest, they received maintenance IL-2 (0.9 x 10(6) IU/m2/d) for 10 days by CIV infusion. Levels I and II were well-tolerated, but, of 6 patients at level III, 1 developed pulmonary infiltrates, 1 developed hypotension (both resolved), and 1 died of bacterial sepsis and acute respiratory distress syndrome. Grade II acute GVHD developed in 1 patient at level I and 1 at level III. The maximum tolerated dose of induction IL-2 was level II. IL-2 induced lymphocytosis, with an increase in CD56+ and CD8+ cells. Ten patients remain in CR at 5+ to 67+ months. Thus, a regimen of IL-2 has been identified that did not induce a high incidence of acute GVHD when administered to children after unmodified allogeneic BMT. Its clinical activity will be assessed in a phase II trial.  相似文献   
105.
106.
Ortega  JA; Shore  NA; Dukes  PP; Hammond  D 《Blood》1975,45(1):83-89
An in vitro marrow culture assay designed to measure erythropoietic capability was used to ascertain the presence of an inhibitor in the sera of patients with congenital hypoplastic anemia (CHA). Marrow cells from nine anemic CHA patients responded to the stimulatory effect of exogenous erythropoietin (EPO) by an increase in heme synthesis in the presence of normal serum. The effect on heme synthesis was less than that observed with normal marrow cells. CHA serum inhibited heme synthesis by both normal and CHA marrow cells. It is concluded that an in-inhibitor of erythropoiesis is present in serum from CHA patients. This inhibitor most likely blocks the EPO-sensitive stem cell receptor sites, causing decreased response to the hormone.  相似文献   
107.
A clonally distinct recurrence of Burkitt's lymphoma at 15 years   总被引:2,自引:0,他引:2  
Lister  J; Miklos  JA; Swerdlow  SH; Bahler  DW 《Blood》1996,88(4):1407-1410
A human immunodeficiency virus-negative male was successfully treated for two occurrences of Burkitt's lymphoma, 15 years apart. As consolidation of his second remission, he underwent high-dose chemotherapy with peripheral blood stem cell transplantation. In an effort to prove whether the second lymphoma was a relapse of the first or a second primary lymphoma, we obtained paraffin-embedded material from both lymphomas. DNA was extracted from this material and amplified by polymerase chain reaction (PCR) using consensus JH and VH region primers. Analysis of the PCR products, which mostly reflects VDJ joints, showed two sharp bands of different molecular size, proving the monoclonal nature of the lymphomas and suggesting that each had different Ig gene rearrangements. Sequencing of both PCR products showed a marked dissimilarity in nucleotide sequence in the clonally unique VDJ joint region, providing strong evidence for the separate cellular genesis of each lymphoma. These results suggest that late relapses of Burkitt's lymphoma should be examined for clonal distinctiveness. If the second lymphoma is distinct from the primary one, it might be treated as a primary lymphoma rather than as recurrent disease.  相似文献   
108.
Hepatic spiral CT: reduction of dose of intravenous contrast material   总被引:13,自引:0,他引:13  
  相似文献   
109.
110.
PURPOSE/METHOD: We present a case of a patient who developed recurrent epithelial herpes simplex keratitis after starting treatment with latanoprost. Her ophthalmic history was only remarkable for a past episode of herpetic keratitis 21 years previously. RESULTS/CONCLUSIONS: Episodes of herpetic keratitis were under remission only when latanoprost was discontinued. No recurrences of herpes simplex keratitis have been observed since then. Latanoprost usage might be associated with recurrent episodes of herpes simplex keratitis in patients with previous history of ocular herpes simplex virus infection.  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