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   3640篇
  免费   192篇
  国内免费   85篇
耳鼻咽喉   40篇
儿科学   150篇
妇产科学   51篇
基础医学   448篇
口腔科学   45篇
临床医学   239篇
内科学   566篇
皮肤病学   83篇
神经病学   238篇
特种医学   175篇
外科学   453篇
综合类   164篇
预防医学   193篇
眼科学   143篇
药学   498篇
中国医学   44篇
肿瘤学   387篇
  2023年   21篇
  2022年   29篇
  2021年   94篇
  2020年   52篇
  2019年   66篇
  2018年   95篇
  2017年   63篇
  2016年   97篇
  2015年   84篇
  2014年   98篇
  2013年   153篇
  2012年   238篇
  2011年   237篇
  2010年   163篇
  2009年   141篇
  2008年   184篇
  2007年   220篇
  2006年   178篇
  2005年   163篇
  2004年   150篇
  2003年   120篇
  2002年   93篇
  2001年   61篇
  2000年   81篇
  1999年   62篇
  1998年   55篇
  1997年   43篇
  1996年   50篇
  1995年   40篇
  1994年   31篇
  1993年   38篇
  1992年   49篇
  1991年   47篇
  1990年   34篇
  1989年   68篇
  1988年   48篇
  1987年   49篇
  1986年   41篇
  1985年   46篇
  1984年   31篇
  1983年   34篇
  1982年   23篇
  1981年   26篇
  1979年   35篇
  1978年   18篇
  1977年   15篇
  1976年   19篇
  1975年   14篇
  1973年   15篇
  1972年   14篇
排序方式: 共有3917条查询结果,搜索用时 203 毫秒
1.
2.
Kim  SH; Chang  KH; Song  IC; Han  MH; Kim  HC; Kang  HS; Han  MC 《Radiology》1997,204(1):239
  相似文献   
3.
The abdominal compartment syndrome is a life threatening condition resulting from pathologic elevation of the intraabdominal pressure. Prompt diagnosis is required to avoid significant sequelae. Diagnosis of this syndrome is based on clinical findings and intra abdominal pressure monitoring. Treatment consists of decompressive laparotomy, which corrects the pathology. Various surgical techniques are described to manage the open abdomen. Despite considerable attention accorded to this disorder, it is still associated with high morbidity and mortality. This review article deals with the identification of risk factors, pathophysiology, diagnostic criteria and treatment of critically ill patients with the abdominal compartment syndrome.  相似文献   
4.
5.
Carcinoma gallbladder is the commonest malignancy in the Northern part of India. The heavy metals are known carcinogens while trace metals have protective effect. Aim The aim of the study is to estimate the heavy and trace metal (Lead, Zinc, Copper, Cadmium, Chromium, Manganese and Selenium) concentration in serum, bile, tissue and gallstone in patients with gallbladder diseases. Method This is a pilot study conducted in 45 cases (Group – I: 15 cases of carcinoma gallbladder, Group II: 15 patients of cholecystitis with cholelithiasis and Group – III: 15 patients of healthy control), to detect the relationship between the heavy and trace metal concentration and gall bladder carcinoma. Analysis of metal was done using Perkins‐Elmer model 2380 atomic absorption spectrophotometer. Results The serum concentration of copper and nickel was significantly high in carcinoma gallbladder patients as compared to patients with cholecystitis while zinc and selenium is low in carcinoma gallbladder patients. Bile concentration of zinc, selenium and manganese was significantly low in carcinoma gallbladder patients (p < 0.05) as compared to patients of cholelithiasis while cadmium and nickel was high. Tissue concentration of manganese was significantly low in carcinoma gallbladder patients as compared to patients of cholelithiasis while chromium was high. Gallstone concentration of copper, manganese and lead was significantly low in carcinoma gallbladder patients as compared to patients of cholelithiasis. Conclusion The heavy metals are in higher concentration in carcinoma gallbladder while trace metals are in lower concentration indicating possible role of heavy metal in gallbladder carcinogenesis.  相似文献   
6.
7.
Growing rats were exposed to 5 mg/L Pb,ad libitum in drinking water, and administered low or high doses of Mn and Cd intraperitoneal (i.p.) for 30 days. Some groups of animals were also administered combinations of Pb + Mn and Pb + Cd in an identical manner. Analysis of Pb, Mn, and Cd in tissue samples showed the expected dose-dependent accumulation when the metal was administered singly. However, combined treatment produced different types of metal shift in different tissues. Enhanced accumulation of all three metals in the brain, Mn in liver, Pb in kidney and Cd in testis and kidney after combined exposure may make target organs vulnerable to the toxic effects of metals, even when encountered at low concentrations. Further, the decreased levels of blood Pb after combined treatment with Cd or Mn suggests that the significance of blood Pb level as a diagnostic aid for Pb toxicity in coexposed conditions may not be of much value. Changes in the metallic distribution within the tissues after coexposure may be the result of a competition between the administered metals for common binding sites.  相似文献   
8.
A sublethal concentration of technical grade endosulfan (END) inhibited 35 to 55% of the activities of cytoplasmic malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH), and lactate dehydrogenase (LDH) in the liver and the skeletal muscle of a freshwater catfish, Clarias batrachus, after 7 days of exposure. The activity remained in the inhibited state up to 28 days. The withdrawal of END from the medium after 1 week of exposure gradually restored the activities to control levels within 21 days in the skeletal muscle and 28 days in the liver. The administration of actinomycin D or cycloheximide between the 14th and the 21st day of the withdrawal of END almost completely inhibited the withdrawal-dependent recovery in the activities of all the three enzymes. This indicates de novo synthesis of the enzymes during the recovery period. A conjoint treatment of END and triiodothyronine (T3) raised the activities of cMDH, mMDH, and LDH in the liver and the skeletal muscle up to the control levels. This shows that the inhibitory effect of END may be relieved in presence of T3. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed few changes in the pattern of cytoplasmic proteins of the liver and the skeletal muscle in response to exposure to END.  相似文献   
9.
10.
Asymptomatic infection with Loa loa, an eye worm, is reported in a 32-year old Zambian woman. The patient revealed up to 28% eosinophilia but microfileraemia was not noticed. One gravid female parasite 56 X 0.56 mm, extracted from lower lid of left eye of the patient, is described. Treatment with diethylcarbamazine (DEC) extended over three weeks was successful against another parasite in tissues.  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