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   1503篇
  免费   87篇
  国内免费   113篇
儿科学   69篇
妇产科学   10篇
基础医学   151篇
口腔科学   22篇
临床医学   161篇
内科学   483篇
皮肤病学   41篇
神经病学   32篇
特种医学   363篇
外国民族医学   1篇
外科学   41篇
综合类   40篇
预防医学   54篇
眼科学   12篇
药学   77篇
中国医学   1篇
肿瘤学   145篇
  2023年   3篇
  2022年   4篇
  2021年   6篇
  2020年   5篇
  2019年   8篇
  2018年   14篇
  2016年   20篇
  2015年   20篇
  2014年   17篇
  2013年   35篇
  2012年   20篇
  2011年   38篇
  2010年   55篇
  2009年   52篇
  2008年   39篇
  2007年   85篇
  2006年   42篇
  2005年   63篇
  2004年   22篇
  2003年   30篇
  2002年   29篇
  2001年   26篇
  2000年   34篇
  1999年   45篇
  1998年   97篇
  1997年   100篇
  1996年   109篇
  1995年   65篇
  1994年   61篇
  1993年   67篇
  1992年   16篇
  1991年   33篇
  1990年   28篇
  1989年   52篇
  1988年   38篇
  1987年   53篇
  1986年   29篇
  1985年   45篇
  1984年   19篇
  1983年   17篇
  1982年   25篇
  1981年   20篇
  1980年   31篇
  1979年   11篇
  1978年   12篇
  1977年   16篇
  1976年   26篇
  1975年   15篇
  1970年   2篇
  1966年   1篇
排序方式: 共有1703条查询结果,搜索用时 0 毫秒
91.
92.
CASE REPORT: We present a case of traumatic displacement of corneal flap in the superior temporal quadrant 13 days after LASIK. The flap was repositioned after gentle irrigation of BSS, cleaned the interface and then drying the flap to verify its stability. In the next day the flap was adhered, clear cornea,smooth and visual acuity without correction was 1.00. DISCUSSION: We should try immediately to reposition the flap after traumatic displacement, as in this case.  相似文献   
93.
94.
PURPOSE/METHODS: We report a 34-year-old woman with sytemic lupus erythematosus (S.L.E.) and antiphospholipidic syndrome which presented severe ischaemic retinopathy and neovascular proliferation. RESULTS/CONCLUSIONS: We achieved no progression of the disease and stabilization of visual acuity with panphotocoagulation. We recommend periodic ophtalmologic exams because of the scarce symptomatology.  相似文献   
95.
96.
背景:在亚洲、非洲和欧洲,致病性H5N1流感病毒引起禽流感在家禽和候鸟中爆发流行,还导致了人类发病和死亡。虽然目前H5N1毒株引起人与人之间的传染不太可能,但它仍可能是未来流感大范围流行的潜在威胁因素。本试验的目的就是评价针对H5N1病毒株的裂解病毒疫苗的安全性和免疫原性。方法:对300名志愿者(年龄为18岁~40岁)进行随机、开放标签的、无对照的Ⅰ期试验。300名志愿者被分为6组:7.5mg血凝素加佐剂组(n=50)、7.5mg血凝素不加佐剂组(n=49)、15mg血凝素加佐剂组(n=50)、15mg血凝素不加佐剂组(n=50)、30mg血凝素加佐剂组(n=51)、30mg血…  相似文献   
97.
Cytarabine ocfosfate (YNK01) is a prodrug analogue of cytarabine which is resistant to systemic deamination after oral administration. Following initial studies indicating significant anti-tumour activity of YNK01 a phase II trial was initiated in order to assess the tolerability and efficacy of a combination of this agent with interferon alpha-2b (IFN-alpha2b) in recently diagnosed chronic phase CML patients (n = 98). The treatment was subdivided into cycles consisting of 4 weeks of continuous administration of IFN-alpha-2b (3 MU/m(2)/day 1st week and then 5 MU/m(2)/day) and 14 days of oral YNK01 (600 mg/day 1st cycle). At the end of each cycle the dose of YNK01 was adjusted according to the blood count observed during the previous 4 weeks. The median time from diagnosis to inclusion in the trial was 2 months (range 6 days to 7.5 months). At 12 weeks, 62 patients (63%; 95% CI, 54-73) achieved a complete hematological response. At 24 weeks, of 98 patients, two achieved a complete cytogenetic response, 14 a partial response (16% major cytogenetic response rate; 95% CI, 9-24) and 34 a minor response; 19 patients were not evaluable for cytogenetic response. During the trial, 20 patients progressed to accelerated (6) or blastic phases (14). The median time to progression was 15 months (range 2-38 months). At 3 years the overall survival was 79% (95% CI, 70-88). Although the complete hematological response rate compared favorably with the 40% response rate previously obtained with the subcutaneous formulation of Ara-c, the cytogenetic response rate was less than expected. Most of the patients experienced side-effects and all permanently stopped YNK01. Although the combination seems attractive the initial dose of 600 mg per day is probably too high and should be reconsidered in further trials.  相似文献   
98.
R115777, a nonpeptidomimetic farnesyl transferase inhibitor has recently demonstrated a significant antileukemic activity in vivo in acute myeloid leukemia. Multiple myeloma (MM) is a fatal hematological malignancy characterized by an accumulation of long-lived plasma cells within the bone marrow. In the present study, we have investigated the effect of the R115777 on growth and survival of myeloma cells. We have found that R115777 induced (1) a significant and dose-dependent growth inhibition of the three myeloma cell lines tested; and (2) a significant and time-dependent apoptosis. R115777 also induced apoptosis in the bone marrow mononuclear cell population of four MM patients, being almost restricted to the malignant plasma cells. Finally, we have investigated the effect of the R115777 in the Ras/MAPK and JAK/STAT pathways which are implicated in survival and/or proliferation in MM. The phosphorylation of both STAT3 and ERK1/2 induced by IL-6 was totally blocked at 15 microM of R115777 and partially blocked when R115777 was used at 10 and 5 microM. The induction of apoptosis by R115777 in myeloma cells and its implication in the regulation of JAK/STAT signalling suggest that R115777 might be an interesting therapeutical approach in MM.  相似文献   
99.

Background  

To reduce the risk of brain damage children with acute lymphoblastic leukaemia (ALL) are nowadays mainly treated with intrathecal chemotherapy (ITC) instead of central nervous system (CNS) radiation therapy (CRT) to prevent CNS relapse. However, chemotherapy may also lead to cognitive deficits. As growth hormone deficiency (GHD) or impaired growth hormone secretion are frequently found in ALL patients treated with cranial radiation therapy and/or chemotherapy, we hypothesized that GH therapy may reduce cognitive deficits in these patients.  相似文献   
100.
While tobacco smoke has been conclusively identified as a lung carcinogen, there is much debate over which smoke constituent(s) are primarily responsible for its carcinogenicity. Previous studies in our laboratory suggested that highly lipophilic carcinogens are slowly absorbed in the thicker epithelium of the conducting airways, potentially allowing for substantial local metabolism. The bioactivation of polycyclic aromatic hydrocarbons in airway epithelium may, hence, be important in tobacco smoke-induced carcinogenesis. In the present study, the hypothesis of slow absorption and substantial local metabolic activation of highly lipophilic carcinogen in airway epithelium was tested in dogs. A single dose of tritiated benzo[a]pyrene (BaP) dissolved in a saline/phospholipid suspension was instilled in the trachea, just anterior to the carina. At intervals of a few minutes up to 30 min over a 3-h period, blood samples were drawn from the azygous vein, which drains the area around the point of instillation, and from the systemic circulation. Tissue samples were taken at the end of the experiment. The concentration of BaP with depth into the tracheal mucosa was determined with autoradiography. BaP was slowly absorbed into the trachea with a half-time of approximately 73 min, which is consistent with diffusion-limited passage through the epithelium and lead to local doses in the tracheal epithelium that were more than a 1000-fold those of other tissues. The long retention of BaP in the epithelium provided the local metabolizing enzymes with high substrate levels over a long period, resulting in extensive metabolism. At 3 h after the exposure, 23% of the BaP-equivalent activity remained in the tracheal mucosa. Of this fraction, 13% was parent compound, 28% was organic extractable, 31% was water-soluble, and 28-7% of the instilled dose was bound to tracheal tissues. These results explain the tendency of highly lipophilic carcinogens, such as BaP, to induce tumors at the site of entry and, furthermore, indicate that the highly lipophilic components of tobacco smoke and polluted air may be the most important contributors to lung tumors of the conducting airways.   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