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   13013篇
  免费   559篇
  国内免费   64篇
耳鼻咽喉   75篇
儿科学   237篇
妇产科学   119篇
基础医学   1693篇
口腔科学   400篇
临床医学   726篇
内科学   3138篇
皮肤病学   290篇
神经病学   1097篇
特种医学   448篇
外科学   2579篇
综合类   31篇
一般理论   1篇
预防医学   329篇
眼科学   105篇
药学   869篇
中国医学   25篇
肿瘤学   1474篇
  2023年   41篇
  2022年   85篇
  2021年   183篇
  2020年   87篇
  2019年   120篇
  2018年   179篇
  2017年   139篇
  2016年   200篇
  2015年   216篇
  2014年   270篇
  2013年   345篇
  2012年   591篇
  2011年   654篇
  2010年   368篇
  2009年   323篇
  2008年   635篇
  2007年   739篇
  2006年   725篇
  2005年   783篇
  2004年   779篇
  2003年   779篇
  2002年   704篇
  2001年   319篇
  2000年   296篇
  1999年   340篇
  1998年   211篇
  1997年   189篇
  1996年   190篇
  1995年   169篇
  1994年   182篇
  1993年   135篇
  1992年   240篇
  1991年   246篇
  1990年   204篇
  1989年   219篇
  1988年   232篇
  1987年   205篇
  1986年   157篇
  1985年   166篇
  1984年   113篇
  1983年   82篇
  1982年   64篇
  1981年   57篇
  1980年   62篇
  1979年   62篇
  1978年   57篇
  1977年   39篇
  1976年   53篇
  1975年   38篇
  1969年   38篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
Sugar and tooth decays are bound closely. The mechanisms of destruction of the tooth from the glycolyse are known. The role played by the food in the development of the caries is unique. Foods sweetened of all ways, rich in sucrose are responsible of the intervening of the carious lesions. The transformation of the fermentable sugars in lactic with the absence of hygiene and the action conjugated of the bacteria leads to tooth decays in temporary and permanent denture that evolve very quickly in the absence of treatment. Reasons for which the authors put in evidence in this survey, the influence of the food sweetened on the teeth at the children while showing the cases of caries and its complications due to the excessive consumption of fermentable hydrates of carbon.  相似文献   
3.
4.
The absence of the temporary incisors could be to a genetic illness or to some multiple premature extractions. These extractions are the aftermaths of the carious lesions or some traumatisms underwent by the temporary incisors. Beyond measure the loss of the space, the premature loss some temporary incisors very often assign the relational development of the child and disturb its psychological development and the aesthetic function. Across some cases clinics, the authors show that the replacement of the temporary incisors is the therapeutic ideal solution. Indeed, the child prosthesis, replacing the temporary absent incisors, solves the psychological, aesthetic and relational problems of the child.  相似文献   
5.
99mTc-ECD SPECT was performed in 19 patients with cerebrovascular disease, and location, extent, and severity of the lesions on 99mTc-ECD SPECT were compared with those on 123I-IMP SPECT. The initial brain uptake was 5.5 +/- 0.7% of the injected dose at 10 minutes after injection, 5.3 +/- 1.3% at 90 minutes, and clearance from the brain is slow. The distribution in the brain was changed, especially washout from the thalamus was slower than that from other regions. The count ratio of perfusion defect to normal area (D/N) on 99mTc-ECD SPECT was unchanged over the time, and had no significant differences from that on 123I-IMP SPECT. 99mTc-ECD SPECT was superior in detection of the lesion in the basal ganglia, and showed the images with superior spatial resolution due to physical characteristics of 99mTc. However, mild ischemic lesion and peri-infarct area was not clearly visualized, while 123I-IMP SPECT could demonstrate these lesions with better contrast.  相似文献   
6.
We report an 80-year-old Japanese male with four primary malignant tumors: malignant melanoma, prostatic cancer, malignant lymphoma, and renal cell carcinoma, which occurred in that respective order. The combination of malignant melanoma and malignant lymphoma is rare. The patient was treated with BCG after an operation for malignant melanoma. He was also treated with cobalt 60 irradiation after an operation for prostatic cancer. We also discuss other reports of multiple malignant tumors and suggest some possible causes of this patient's primary malignant tumors.  相似文献   
7.
The effect of electric charge on the hepatic disposition of macromolecules was studied in the rat. Charged derivatives of dextran (T-70) and bovine serum albumin (BSA), mitomycin C–dextran conjugates (MMC-D), and lactosaminated BSA (Lac-BSA) were employed as model macromolecules. After intravenous injection, cationic macromolecules were rapidly eliminated from plasma because of their extensive hepatic uptake, while anionic and neutral macromolecules were slowly eliminated. Cationic macromolecules were recovered from parenchymal and nonparenchymal hepatic cells at a cellular uptake (per unit cell number) ratio of 1.4–3.2, while that of Lac-BSA was 14. During liver perfusion using a single-pass constant infusion mode, cationic macromolecules were continuously extracted by the liver, with extraction ratios at steady-state (E ss) ranging between 0.03 and 0.54, whereas anionic and neutral macromolecules were almost completely recovered in the outflow at steady state. The E ss for cationized BSA (Cat-BSA) and cationic MMC-Dcat were concentration dependent and decreased at low temperatures and in the presence of colchicine and cytochalasin B. The possible participation of the internalization process in the uptake of cationic macromolecules by hepatocytes was suggested.  相似文献   
8.
9.
10.
A case of a branchial cyst with a high amylase activity of the cyst fluid was found in a 58-year-old female. The literature on branchial cysts with high amylase activity is reviewed. Amylase that showed high activity in the cystic fluid was revealed to be due to the salivary isoenzymes (S3 and S4) which migrated more to the anodic side on electrophoresis.  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