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   378334篇
  免费   24848篇
  国内免费   2804篇
耳鼻咽喉   5187篇
儿科学   8201篇
妇产科学   10084篇
基础医学   53092篇
口腔科学   11778篇
临床医学   30091篇
内科学   78280篇
皮肤病学   8547篇
神经病学   27200篇
特种医学   13913篇
外国民族医学   82篇
外科学   60567篇
综合类   9955篇
现状与发展   1篇
一般理论   64篇
预防医学   17426篇
眼科学   9448篇
药学   30976篇
  1篇
中国医学   2193篇
肿瘤学   28900篇
  2021年   2608篇
  2019年   2720篇
  2018年   4521篇
  2017年   3432篇
  2016年   3522篇
  2015年   4020篇
  2014年   5693篇
  2013年   7371篇
  2012年   10012篇
  2011年   10195篇
  2010年   6183篇
  2009年   5836篇
  2008年   9443篇
  2007年   10270篇
  2006年   10203篇
  2005年   9260篇
  2004年   8772篇
  2003年   8511篇
  2002年   8182篇
  2001年   28270篇
  2000年   28781篇
  1999年   23663篇
  1998年   5159篇
  1997年   4248篇
  1996年   3829篇
  1995年   3479篇
  1994年   3104篇
  1993年   2843篇
  1992年   16050篇
  1991年   14809篇
  1990年   14154篇
  1989年   13958篇
  1988年   12581篇
  1987年   12061篇
  1986年   11102篇
  1985年   10322篇
  1984年   6915篇
  1983年   5599篇
  1982年   2719篇
  1979年   5480篇
  1978年   3348篇
  1977年   2971篇
  1975年   2641篇
  1974年   3065篇
  1973年   2866篇
  1972年   2828篇
  1971年   2773篇
  1970年   2510篇
  1969年   2544篇
  1968年   2252篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
172.
173.
A study of double immunofluorescence-staining of immunoglobulins and sialic acids in the glomeruli from patients with IgA nephropathy is described. Renal biopsy specimens from patients with IgA nephropathy were stained with rhodamine-labeled antihuman IgA, IgG or IgM antisera and then stained with FITC-labeled Limulus polyphemus (LPA), Tricum vulgaris (WGA) or antihuman C3 antisera. Marked positive stainings of IgA and C3 and positive binding of LPA or WGA were observed in the glomerular mesangial areas from patients with IgA nephropathy. LPA or WGA were not bound with glomerular capillary walls from patients with moderate and advanced stages of IgA nephropathy, although depositions of IgA and C3 were markedly observed in such walls. There was a significant inverse correlation between the deposition of IgA and the binding of LPA or WGA in glomerular capillary walls obtained from these patients with IgA nephropathy. The levels of proteinuria from patients with moderate and advanced stages of IgA nephropathy were significantly higher than those with minimal and slight stages of such disease. It is suggested that the decrease of sialic acids in glomerular capillary walls might be due to a deposition of IgA in some patients with IgA nephropathy. It is concluded that high levels of proteinuria might be due to the decrease of sialic acids in glomerular capillary walls from patients with moderate and advanced stages of IgA nephropathy.  相似文献   
174.
A combination of Photo Radiation Therapy (PRT) using Argon-Dye Laser with hematoporphyrin derivatives (HpD) was used experimentally on a cytogenetically highly malignant neuroblastoma xenograft, which exhibited a homogeneously staining region and caused DNA amplifications in chromosomes. The tumor tissue was treated with 500 joules/cm2 of laser. The dosage of HpD was 50 mg per kg body weight. Necrosis of over 50% of the tumor was observed in half the specimens. Swollen cytoplasmic organelles and ruptured cell and nuclear membranes were observed by electron microscopy after PRT. PRT may be used with other treatment modalities for the removal of residual and metastatic tumors.  相似文献   
175.
Carnitine status in Reye and Reye-like syndromes   总被引:4,自引:0,他引:4  
Fourteen children with the following Reye and Reye-like syndromes were studied to determine each patient's carnitine status: valproate-induced Reye-like attack, ornithine transcarbamylase deficiency, systemic carnitine deficiency, methylmalonic acidemia, and propionic acidemia. Reduced free carnitine and increased serum and urine acylcarnitine levels were found in all patients except for 2 with Reye syndrome, in whom serum creatinine levels were mildly elevated and serum free carnitine levels were not reduced. The renal free carnitine reabsorption rate was reduced in all cases. The free carnitine content of autopsied liver samples were reduced in 2 Reye syndrome patients, 2 OTC deficiency patients, and in a single systemic carnitine deficiency patient. The observed secondary free carnitine deficiency may be a factor in the pathogenesis of Reye and Reye-like syndromes.  相似文献   
176.
The influence of food and water intake on mefenamic acid (N-2,3-xylylanthranilic acid) bioavailability from commercial capsules of high bioavailability was studied in four healthy male volunteers. The drug was administered as a single oral dose of 250 mg, under fasting or nonfasting conditions, and a 4 X 4 Latin-square design was used. Eight blood samples were collected over a 24-h period following drug administration, and the drug plasma concentrations were determined by HPLC. The bioavailability of mefenamic acid from capsules was markedly influenced in the fasting subjects by the water but not by the food intake. A good correlation was found between the bioavailability and amount of water ingested with the drug in the fasting subjects. The area under the plasma concentration-time curve (AUC0-infinity) of mefenamic acid was highest when the capsule was taken with 50 mL of water or immediately after a meal. Increasing the amount of water from 50 to 500 mL in the fasting subjects caused a significant reduction in AUC0-infinity.  相似文献   
177.
178.
179.
Forty-nine cases of gastroduodenal perforation were subjected to new air insufflation test. The clinical and radiological criteria of air insufflation test were applied to every patient of this study. Forty-seven cases (95.9%) were positive to the new test whereas 2 negative cases turned out to be old sealing perforation. The new test is highly useful in preoperative detection of site of perforation in perforative peritonitis.  相似文献   
180.
In the clinical management of Graves' thyrotoxicosis, one of the most important subject is when to stop antithyroid drugs after achieving an euthyroid state. T3 suppression test and other methods have been used to forecast the outcome after drug cessation, but the results were not always satisfactory. We have attempted to predict remission of Graves' disease by single measurement of early technetium uptake without administration of triiodothyronine. Drugs were discontinued in the seventy-five patients with Graves' disease on maintenance doses of either methimazole or propylthiouracil who showed normalized uptake (4.0% or less). Of 64 patients evaluable after twelve months, 55 (86%) remained euthyroid, 8 relapsed, and 1 became hypothyroid. With its accuracy in prediction of short-term remission comparable or superior to T3 suppression test, this rapid and simple method seemed suitable for routine use in clinical practice.  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