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   1372篇
  免费   115篇
  国内免费   37篇
耳鼻咽喉   15篇
儿科学   59篇
妇产科学   23篇
基础医学   157篇
口腔科学   34篇
临床医学   158篇
内科学   281篇
皮肤病学   11篇
神经病学   42篇
特种医学   239篇
外科学   193篇
综合类   22篇
预防医学   73篇
眼科学   11篇
药学   67篇
中国医学   26篇
肿瘤学   113篇
  2020年   7篇
  2019年   19篇
  2018年   26篇
  2017年   18篇
  2015年   22篇
  2014年   29篇
  2013年   57篇
  2012年   43篇
  2011年   36篇
  2010年   51篇
  2009年   50篇
  2008年   39篇
  2007年   64篇
  2006年   38篇
  2005年   41篇
  2004年   33篇
  2003年   36篇
  2002年   25篇
  2001年   29篇
  2000年   24篇
  1999年   26篇
  1998年   55篇
  1997年   55篇
  1996年   57篇
  1995年   58篇
  1994年   48篇
  1993年   29篇
  1992年   21篇
  1991年   48篇
  1990年   22篇
  1989年   42篇
  1988年   36篇
  1987年   34篇
  1986年   35篇
  1985年   23篇
  1984年   26篇
  1983年   16篇
  1982年   15篇
  1981年   13篇
  1980年   16篇
  1979年   11篇
  1978年   17篇
  1977年   14篇
  1976年   13篇
  1975年   9篇
  1974年   8篇
  1973年   11篇
  1972年   11篇
  1971年   7篇
  1968年   7篇
排序方式: 共有1524条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
PURPOSE: To assess the response of hepatic metastases after treatment with intraarterial yttrium 90 radioembolization (ie, use of SIR-Spheres) with use of [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). MATERIALS AND METHODS: Nineteen patients with metastatic cancer to the liver from various solid tumors with progression despite polychemotherapy were included. All patients underwent baseline computed tomography, FDG PET, hepatic angiography, and intraarterial technetium 99 m macroaggregated albumin scan for assessment of lung shunting fraction. Patients were treated with 90Y resin microspheres on a lobar basis and were monitored for 3 months with use of dedicated attenuation-corrected PET. For each patient, regions of interest were drawn along the liver edge to measure total liver standard uptake value (SUV) on axial images, covering the entire liver. Visual estimates were also performed and graded as +1, 0, -1, -2, or -3 for progression, no change, and mild, moderate, and dramatic improvement by posttreatment PET. RESULTS: The median absorbed dose for the tumor was 76 Gy. There was a significant overall decrease in total liver SUV after treatment (baseline, 71,134 +/- 38,055; after SIR-Sphere treatment, 59,941 +/- 26,509; P = .028) for the entire group. Visual estimates placed 15 patients (79%) in response categories (-3 to -1) and four patients (21%) in nonresponse categories (0 to +1) for the liver. The percentage change of total liver SUV after treatment in the response group (-19%) was significantly greater and different in direction than that in the nonresponse group (+27%; P = .03). This percentage change was also correlated significantly with the respective visual estimates (r = 0.72; P < .0005) for each individual patient. Three patients had major complications related to hyperbilirubinemia (transient, n = 1; permanent, n= 2). CONCLUSIONS: The results suggest that there is significant reduction of hepatic metastatic load as evaluated objectively by PET after 90Y radioembolization for the treatment of unresectable metastatic disease to the liver. 90Y radioembolization provides encouraging results by arresting progression of metastatic cancer to the liver.  相似文献   
95.
96.
In a postmortem study of a patient with adult-onset acid maltase deficiency (AMD), morphological abnormalities were confined to skeletal muscle and consisted of a vacuolar myopathy. Acid maltase activity, however, was approximately 6% of normal in muscle, liver, and brain, and 3% of normal in heart. Kinetic characteristics, and inhibition by antibodies and Zn++, showed that the residual activity was “authentic” acid maltase. Neutral maltase activity was normal in muscle and liver, but decreased in brain (55% of normal) and heart (19% of normal). Although the relative decrease of acid maltase was similar in different tissues, absolute residual activity was lowest in skeletal muscle: this may explain the selective involvement of this tissue in late-onset AMD.  相似文献   
97.
In four-day cycling rats studied during the estrous cycle, the levels of circulating norepinephrine (NE) showed a sharp rise concomitant with the LH surge in the afternoon of proestrus. Following the peak, plasma NE fell rapidly to the minimum value by the morning of estrus. The administration of progesterone to ovariectomized estrogen-primed rats resulted in a surge in plasma NE levels 4 h after progesterone treatment. The maximal levels attained were 3-fold greater than baseline values, falling rapidly to reach basal values 8 h after the administration of progesterone. The amine levels remained unaffected 12-20 h later. The LH values attained a maximum 8 h after the injection of progesterone. In rats treated with estradiol benzoate (EB) followed by 0.1 ml of oil instead of progesterone, neither the NE nor the LH peak were observed. These findings are discussed with respect to the significance of increased amounts of plasma NE related to the LH surge.  相似文献   
98.
Laparoscopic adhesiolysis for small bowel obstruction   总被引:15,自引:0,他引:15  
BACKGROUND: Historically, laparotomy and open adhesiolysis have been the treatment for patients requiring surgery for small bowel obstruction. Laparoscopic adhesiolysis has not gained wide acceptance. The indications and outcomes of laparoscopic adhesiolysis for small bowel obstruction are not well established. The purpose of this paper is to review the literature on laparoscopic adhesiolysis for small bowel obstruction and to discuss patient selection, surgical technique, and outcomes. DATA SOURCES: Medline search from 1980 to 2002. CONCLUSIONS: Laparoscopic adhesiolysis has been shown to be safe and feasible in experienced hands. For selected patients, laparoscopic adhesiolysis offers the advantages of decreased length of stay, faster return to full activity, and decreased morbidity. Patient selection and surgical judgment appear to be the most important factors for a successful outcome.  相似文献   
99.
100.
An assay for inhibitors of LFA-1/ICAM-1 mediated cell-cell adhesion has been employed to identify new pharmacologically active compounds from marine cyanobacteria and algae. From a panel of sixty unusual marine natural products, seventeen compounds inhibited LFA-1/ICAM-1-based cell aggregation without showing significant cytotoxicity in the primary assay. Six compounds inhibited the cell-cell adhesion of HL-60 cells to CHO-ICAM-1 cells. The unusual oxylipin Cymathere aldehyde methyl ester (IC (50) 3.5 microM), cyanobacterial lipopeptides microcolins B (IC (50) 0.15 microM) and D (IC (50) 0.9 microM), bromophenol avrainvilleol (IC (50) 2.2 microM), sesquiterpene cymopol (IC (50) 2.7 microM), and cryptophyte derived compound styrylchromone hormothamnione diacetate (IC (50) 1.5 microM) significantly inhibited LFA-1/ICAM-1 mediated cell adhesion. The pharmacological activity and structure-activity relationships of selected marine algal metabolites are described. Abbreviations. LFA-1:Lymphocyte function-associated molecule-1 ICAM-1:Intercellular cell adhesion molecule-1 PMA:Phorbol 12-myristate 13-acetate HL-60:Promyelocytic human leukemia-60 CHO:Chinese hamster ovary  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