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   3557篇
  免费   244篇
  国内免费   14篇
耳鼻咽喉   32篇
儿科学   171篇
妇产科学   84篇
基础医学   407篇
口腔科学   137篇
临床医学   375篇
内科学   662篇
皮肤病学   186篇
神经病学   293篇
特种医学   196篇
外科学   397篇
综合类   32篇
一般理论   2篇
预防医学   292篇
眼科学   18篇
药学   343篇
中国医学   4篇
肿瘤学   184篇
  2021年   42篇
  2020年   28篇
  2019年   39篇
  2018年   66篇
  2017年   41篇
  2016年   56篇
  2015年   61篇
  2014年   78篇
  2013年   126篇
  2012年   123篇
  2011年   139篇
  2010年   98篇
  2009年   78篇
  2008年   149篇
  2007年   163篇
  2006年   157篇
  2005年   122篇
  2004年   109篇
  2003年   127篇
  2002年   120篇
  2001年   123篇
  2000年   129篇
  1999年   124篇
  1998年   49篇
  1997年   54篇
  1996年   48篇
  1995年   45篇
  1994年   43篇
  1993年   28篇
  1992年   73篇
  1991年   74篇
  1990年   84篇
  1989年   90篇
  1988年   77篇
  1987年   79篇
  1986年   70篇
  1985年   71篇
  1984年   48篇
  1983年   49篇
  1982年   29篇
  1981年   30篇
  1980年   30篇
  1979年   39篇
  1978年   32篇
  1977年   37篇
  1976年   27篇
  1975年   29篇
  1972年   34篇
  1971年   26篇
  1969年   28篇
排序方式: 共有3815条查询结果,搜索用时 15 毫秒
1.
2.
In our health jurisdiction the proportion of elderly people is more than double the national average, and there is a severe shortage of both home care services and long-term care beds. To help the many elderly housebound people without primary medical care we initiated a medical services home care program. The goals were patient identification, clinical assessment, medical and social stabilization, matching of the housebound patient with a nearby family physician willing and able to provide home care and provision of a backup service to the physician for consultation and help in arranging admission to hospital if necessary. In the program's first 2 years 105 patients were enrolled; the average age was 78.9 years. More than 50% were widowed, single, separated or divorced, over 25% lived alone, and more than 40% had no children living in the city. In almost one-third of the cases there had never been a primary care physician, and in another third the physician refused to do home visits. Before becoming housebound 15% had been seeing only specialists. Each patient had an average of 3.2 active medical problems and was functionally quite dependent. Thirty-five of the patients were surveyed after 1 year: 24 (69%) were still at home, and only 1 (3%) was in a long-term care institution; 83% were satisfied with the care provided, and 79% felt secure that their health needs were being met. One-third of the patients or their families said that it was not easy to reach the physician when necessary. We recommend that programs similar to ours be set up in health jurisdictions with a high proportion of elderly people. To recruit and retain cooperative physicians hospital geriatric services must be willing to provide educational, consultative and administrative support.  相似文献   
3.
The aim of this study in pigs was to investigate the local pharmacokinetics of fexofenadine in the intestine and liver by using the pig as a model for drug transport in the entero-hepatobiliary system. A parallel group design included seven pigs (10-12 weeks, 22.2-29.5 kg) in three groups (G1, G2, G3), and a jejunal single-pass perfusion combined with sampling from the bile duct and the portal, hepatic, and superior caval veins was performed. Fexofenadine was perfused through the jejunal segment alone (G1: 120 mg/l, total dose 24 mg) or with two different verapamil doses (G2: 175 mg/l, total dose 35 mg; and G3: 1000 mg/l, total dose 200 mg). The animals were fully anesthetized and monitored throughout the experiment. Fexofenadine had a low liver extraction (E(H); mean +/- S.E.M.), and the given doses of verapamil did not affect the E(H) (0.13 +/- 0.04, 0.16 +/- 0.03, and 0.12 +/- 0.02 for G1, G2, and G3, respectively) or biliary clearance. The E(H) for verapamil and antipyrine agreed well with human in vivo data. Verapamil did not increase the intestinal absorption of fexofenadine, even though the jejunal permeability of fexofenadine, verapamil, and antipyrine showed a tendency to increase in G2. This combined perfusion and hepatobiliary sampling method showed that verapamil did not affect the transport of fexofenadine in the intestine or liver. In this model the E(H) values for both verapamil and antipyrine were similar to the corresponding values in vivo in humans.  相似文献   
4.
5.
B Bergman 《Urology》1990,35(5):393-398
A follow-up study of 26 patients operated on for suspicion of primary aldosteronism was made. The preoperative investigative procedures, including serum potassium concentration, urinary aldosterone excretion, and plasma renin activity, could not differentiate between patients with cortical adenomas and those with cortical hyperplasia or normal glands. Preoperative roentgenologic examinations visualized only one third of the adenomas. Altogether 44 of the 52 suprarenal glands had to be explored to reveal the 21 adenomas. Patients with cortical adenoma often became normotensive, in contrast to those with cortical hyperplasia or normal adrenal glands histopathologically. The suprarenal glands were explored from behind according to Nesbit. The complications were few and minor.  相似文献   
6.
Whole-body autoradiography was used to study the tissue distribution of the plasticizer di-(2-ethylhexyl) adipate (DEHA), labelled in the acid [carbonyl-14C] or alcohol [2-ethylhexyl-1-14C]moiety, after iv or ig administration to male mice and rats and pregnant mice. With both DEHA preparations, during the first 24 hr after administration high levels of radioactivity were observed particularly in the body fat, liver and kidneys (after iv and ig administration) and in the intestinal contents (after ig administration) of both species. After administration of [carbonyl-14C]DEHA, radioactivity was also registered in the adrenal cortex, corpora lutea of the ovary, bone marrow, forestomach mucosa, salivary glands and Harder's gland in both species. [2-ethylhexyl-1-14C]DEHA derived radioactivity was found in the bronchi in male mice. Radioactivity was observed in the foetal liver, intestine and bone marrow during the first 24 hr after iv or ig administration of [carbonyl-14C]DEHA to pregnant mice. There was very little accumulation of [2-ethylhexyl-1-14C]DEHA in the mouse foetus but some was found in the urinary bladder, liver and intestinal contents as well as in the amniotic fluid. In an absorption/elimination study in rats of doses of 25 microCi/kg body weight of [14C]DEHA administered ig, dissolved in corn oil or dimethylsulphoxide, blood levels of radioactivity increased somewhat faster and were two or three times higher when DMSO was the vehicle indicating poor absorption of DEHA from the corn oil solution which more accurately reflects human contact with DEHA. Little radioactivity from [carbonyl-14C]DEHA was recovered in the bile, whereas [2-ethylhexyl-1-14C]DEHA was excreted in the bile in significant amounts particularly when DMSO was the vehicle. There was evidence of enterohepatic circulation of DEHA. Radioactivity was also excreted in the urine. As shown by autoradiograms obtained 4 days after the administration of [14C]DEHA there was no retention of DEHA and/or its metabolites in the tissues of mice.  相似文献   
7.
In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population.  相似文献   
8.
9.
The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.  相似文献   
10.
The aim of this study was to analyse the frequency and pattern of family (domestic) violence in a group of psychiatric in-patients by using the Conflict Tactics Scale. The study is based on a consecutive series of 55 married or cohabiting psychiatric in-patients treated at Huddinge Hospital, Stockholm, Sweden in 1994. The study shows that males and females use similar types of both violent and non-violent strategies when trying to solve marital conflicts. Depressed patients use both non-violent and violent methods less often than non-depressed patients, while the opposite is true for patients with a personality disorder, and for schizophrenics. Psychosocial stressors appear to be of limited importance in this context, while poor general functioning is associated with destructive ways of trying to solve conflicts between husband and wife. However, there have been no Scandinavian population-based studies to establish the frequency and type of violence used when trying to solve marital conflicts. Thus there is a need for such studies, and the present investigation supports the American experience that the Conflict Tactics Scale is a usable and easily administered instrument for population-based studies.  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