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   25469篇
  免费   1333篇
  国内免费   117篇
耳鼻咽喉   131篇
儿科学   430篇
妇产科学   317篇
基础医学   3392篇
口腔科学   739篇
临床医学   1702篇
内科学   5921篇
皮肤病学   479篇
神经病学   2477篇
特种医学   1138篇
外科学   4415篇
综合类   99篇
现状与发展   1篇
预防医学   828篇
眼科学   607篇
药学   1972篇
中国医学   62篇
肿瘤学   2209篇
  2023年   114篇
  2022年   182篇
  2021年   535篇
  2020年   257篇
  2019年   379篇
  2018年   504篇
  2017年   397篇
  2016年   465篇
  2015年   474篇
  2014年   626篇
  2013年   794篇
  2012年   1268篇
  2011年   1459篇
  2010年   770篇
  2009年   638篇
  2008年   1177篇
  2007年   1345篇
  2006年   1352篇
  2005年   1315篇
  2004年   1250篇
  2003年   1198篇
  2002年   1195篇
  2001年   810篇
  2000年   822篇
  1999年   772篇
  1998年   303篇
  1997年   243篇
  1996年   217篇
  1995年   177篇
  1994年   163篇
  1993年   172篇
  1992年   546篇
  1991年   491篇
  1990年   458篇
  1989年   446篇
  1988年   433篇
  1987年   372篇
  1986年   364篇
  1985年   368篇
  1984年   212篇
  1983年   170篇
  1982年   99篇
  1981年   91篇
  1980年   88篇
  1979年   172篇
  1978年   128篇
  1977年   96篇
  1974年   129篇
  1973年   115篇
  1969年   102篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
With the purpose of obtaining more potent and selective gastric prokinetic than metoclopramide (1), a new series of N-[(2-morpholinyl)alkyl]benzamides (17-52) were synthesized and their gastric prokinetic activity was evaluated by determining effects on the gastric emptying of phenol red semisolid meal and of resin pellets solid meal in rats and mice. The morpholinyl moiety was newly designed after consideration of the side-chain structure of cisapride (2) and produced the desired activity when coupled with the 4-amino-5-chloro-2-methoxybenzoyl group of both metoclopramide and cisapride. Modification of the substituents of the benzoyl group markedly influenced the activity. In particular, 4-amino-N-[(4-benzyl-2-morpholinyl)methyl]-5-chloro-2-methoxybenzamide (17) and the 4-(dimethylamino) and 2-ethoxy analogues (25 and 29) of 17 showed potent and selective gastric prokinetic activity along with a weak dopamine D2 receptor antagonistic activity.  相似文献   
32.
A retrospective study compared the course of alcohol withdrawal, including delirium tremens, in women and men hospitalized in the Nowowiejski Hospital in Warsaw from 1973 to 1987. Medical records pertaining to 1179 patients were analyzed; 13.8% of these patients were women and 86.2% were men. The study showed that women began intensive alcohol drinking later than men ( p < 0.0001), but the period between the onset of alcohol abuse and the first occurrence of alcohol withdrawal was shorter in women than in men ( p < 0.0001). In the period of heavy drinking before hospitalization, women consumed significantly less alcohol then men ( p < 0.0001); moreover, women drank nonbeverage alcohol less frequently than men ( p < 0.05). Women were hospitalized substantially longer than men ( p < 0.0001), whereas the duration of alcohol withdrawal symptoms at the time of hospitalization was comparable in both groups. Withdrawal seizures were significantly more frequent among men than among women ( p < 0.001). Significant differences in the patients'somatic conditions were not noted between the groups, with the exception of anemia and decreased potassium concentration, which were more frequently observed in women (both p < 0.0001), and of increased concentration of ALT and hypoproteinemia, which were more frequent in men (respectively, p < 0.05 and p < 0.01). Co-existing personality disorders, depressive disorders, and anxiety disorders—as well as abuse of benzodiazepines and barbiturates—were more frequently observed in women ( p < 0.0001). The period between the first hospitalization due to alcohol withdrawal and the time of death was significantly shorter in men than in women ( p < 0.05). The results point to differences in the conditions and the course of alcohol dependence and alcohol withdrawal between women and men.  相似文献   
33.
We report a case of anuria in a premature neonate secondary to bilateral ureteropelvic junction obstructions related to Candida bezoars. Percutaneous decompression and drainage of both kidneys contributed significantly to the successful management of renal candidiasis in this patient. A review of the literature is presented.  相似文献   
34.
The divalent cation zinc has been reported to possess several physiological properties such as blocking apoptotic cell death through an inhibitory effect on Ca2+-Mg2+ endonuclease activity, or modulating the neurotoxicity via glutamate receptor subtypes. In the present study, we investigated the effect of peripherally injected zinc on delayed neuronal death seen in the hippocampus after transient global ischemia, in order to elucidate a possible beneficial role on zinc in ischemic neuronal cell death. Forty-five adult Mongolian gerbils of both sexes underwent transient bilateral clipping of the common carotid arteries for 3 min. In the pretreated animals, ZnCl2 (20 mg/kg) was injected subcutaneously once, 1 h before ischemia (superacute group; n=6) or twice at 24 and 48 h before ischemia (subacute group; n=14). Histological survey was carried out 3 days later by in situ DNA fragmentation method and 4 days later by hematoxylin-eosin staining by semiquantatively counting dead neurons in the CA1 sector. Subacute zinc pre-administration significantly reduced the nuclear damage and subsequent neuronal death; however, superacutely pre-administered zinc did not protect hippocampal neurons against ischemia but it did not aggravate the effect of ischemia, either. The present study suggested that transfer of exogenous zinc into the intracellular space is required for neuroprotection, presumably via the anti-endonuclease activity.  相似文献   
35.
36.
We encountered a rare case of hypersensitivity pneumonitis associated with bilateral hilar lymphadenopathy (BHL). The patient was a 53-year-old male, who developed dry cough and shortness of breath when using a humidifier since 1982. He was admitted to our hospital for further evaluation in 1987. Chest X-ray films showed BHL and ground glass appearance in the bilateral lung fields. Pulmonary function test indicated disturbance of diffusing capacity. Transbronchial lung biopsy revealed interstitial pneumonitis, and lymph node biopsy by mediastinoscopy showed lymphoid sinus histiocytosis without noncaseating granuloma. Provocation test using the humidifier was positive, and the diagnosis of humidifier lung with BHL was made.  相似文献   
37.
We have treated advanced transitional-cell carcinoma of the urothelial tract with methotrexate, vinblastine, Adriamycin, and cisplatin (M-VAC) chemotherapy since July of 1985. We analyzed the effect of that chemotherapy in 26 patients with advanced urothelial cancer who were treated in our hospital and followed up. They were divided into two groups. Group 1 consisted of 15 patients with distant metastases. In all, 11 of them received M-VAC as adjuvant chemotherapy for metastatic lesions after surgical removal of the primary lesion, and the remaining 4 patients were not operable since they had very advanced-stage tumors; they received only M-VAC chemotherapy. Group 2 contained 11 patients who received M-VAC neo-adjuvant chemotherapy. In group 1, the overall response rate was 57.1% and the mean duration of response was 12.6 months. In the 11 patients who had received M-VAC as adjuvant therapy after surgical removal of the primary tumor, the mean duration of response was 14.1 months. After M-VAC chemotherapy, six patients underwent surgical resection of metastatic lesions and restaging was done pathologically in these cases. The clinical response coincided with the pathological response in all six cases. In group 2,5 of 11 patients experienced histological downstaging of the resected bladder. M-VAC chemotherapy combined with surgical resection of residual tumors has proved to be an effective option against advanced urothelial cancer.Presented at the 4th International Conference on Treatment of Urinary Tract Tumors with Adriamycin/Farmorubicin, 16–17 November 1990, Osaka, Japan  相似文献   
38.
K Matsumoto 《Arerugī》1992,41(12):1679-1686
To evaluate the clinical features of respiratory syncytial virus (RSV) infection and relation with bronchial asthma, 233 infants hospitalized for lower respiratory tract infection during winters from 1988 to 1990 were enrolled in this study. RSV antigen was detected from half of them by immunofluorescent antibody test. Children with RSV infection showed the characteristic findings as follows; wheeze (71.6%), elevated serum 2-5 AS activity, a marker for viral infection, low level of acute phase reactants. Patients whose family members with major allergy experienced more frequent episodes of wheeze. Since the initial RSV infection could cause wheeze among infants from atopic families and recurrent wheezy infants could be recognized as in the pre-stage of infantile asthma, we should follow these infants with RSV infection closely.  相似文献   
39.
40.
Transrectal ultrasonotomography is useful in following patients with benign prostatic hypertrophy, because prostatic shape and weight are precisely assumed. We studied the effect of chlormadinone acetate (CMA) on benign prostatic hypertrophy. CMA (50 mg/day) was administered to 30 patients with benign prostatic hypertrophy. Weight reduction over 10% of the gland was noticed in 24 cases (80%). Mictional conditions were improved in 70% subjectively and in 71.4% objectively. However, the number of nocturia decreased in only 18.9%. Reduction rate of the weight was unrelated with the weight of prostate before administration of CMA. Duration of administration of CMA and the reduction rate were estimated. There was no definite difference in reduction rate for the first 15 months, but there was a slightly high reduction rate after administration of CMA for more than 24 months. In 3 cases, the shape and weight of prostate were studied after discontinuation of CMA. The size of prostate showed a tendency to increase gradually.  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