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   24685篇
  免费   2537篇
  国内免费   27篇
耳鼻咽喉   226篇
儿科学   698篇
妇产科学   589篇
基础医学   3368篇
口腔科学   623篇
临床医学   2918篇
内科学   5116篇
皮肤病学   353篇
神经病学   2377篇
特种医学   836篇
外科学   3215篇
综合类   582篇
一般理论   15篇
预防医学   2552篇
眼科学   456篇
药学   2121篇
  1篇
中国医学   29篇
肿瘤学   1174篇
  2021年   361篇
  2019年   351篇
  2018年   412篇
  2017年   332篇
  2016年   315篇
  2015年   371篇
  2014年   519篇
  2013年   772篇
  2012年   1117篇
  2011年   1157篇
  2010年   671篇
  2009年   557篇
  2008年   1002篇
  2007年   1173篇
  2006年   1089篇
  2005年   1133篇
  2004年   1000篇
  2003年   1068篇
  2002年   954篇
  2001年   687篇
  2000年   694篇
  1999年   597篇
  1998年   288篇
  1997年   237篇
  1996年   220篇
  1995年   262篇
  1994年   239篇
  1993年   213篇
  1992年   523篇
  1991年   485篇
  1990年   468篇
  1989年   468篇
  1988年   425篇
  1987年   425篇
  1986年   372篇
  1985年   442篇
  1984年   375篇
  1983年   300篇
  1982年   289篇
  1981年   235篇
  1980年   241篇
  1979年   345篇
  1978年   296篇
  1977年   208篇
  1976年   247篇
  1975年   213篇
  1974年   272篇
  1973年   284篇
  1972年   232篇
  1971年   213篇
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
81.
82.
83.
A case of meningitis secondary to acute suppurative otitis media in a previously healthy child is reported. The only organism isolated from blood after aerobic and prolonged anaerobic culture was identified as Fusobacterium necrophorum. Complete recovery followed treatment with surgery and prolonged antibiotic therapy. The role of anaerobes in the development of meningitis, the isolation and identification of Fusobacterium necrophorum, the clinical presentations of F. necrophorum infection and the choice of antibiotics in the treatment of these infections are discussed.  相似文献   
84.
85.
The aim of this investigation was to determine whether age-related changes in the dynamics of muscle activation were, in part, responsible for longer reaction times (RT) in the elderly. A group of 12 young (mean age, 20.6 years) and 12 elderly (mean age, 64.3 years) women performed a series of ballistic forearm supination movements in response to an auditory stimulus while using a simple reaction time test. Surface electromyographic waveforms from biceps brachii (agonist) and pronator teres (antagonist) muscles were recorded, together with the angle-time curves representing the motion of the forearm, on to an IBM compatible microcomputer. The results showed that an age-related increase (P<0.05) in motor reaction time (MRT) contributed to longer RT in the elderly. In addition, the longer (P<0.05) MRTs in the elderly were associated with a significantly slower rate (P<0.05) of biceps brachii muscle activation and a significantly increased proportion (P<0.05) of the initial biceps brachii muscle burst required to initiate the movement. This data suggested that an important part of the slowing of motor behaviour, commonly observed with increasing age, may be due to either decreases in the ability of aged skeletal muscle to rapidly generate tension or to a reduction in motor drive.  相似文献   
86.
Functional use of the Nucleus 22-channel cochlear implant in the elderly   总被引:1,自引:0,他引:1  
A questionnaire was sent to 101 Nucleus 22-channel cochlear implant recipients aged 65 years and older to investigate the perceived impact of cochlear implantation on their quality of life. The questionnaire was designed to gain insight into the patient's daily use of the Nucleus implant. Sixty-seven questionnaires were returned over a 3-month period. The results of the survey showed that elderly cochlear implant patients obtained similar benefits to younger adult patients who were implanted with the same device. We believe that the results of this study will aid other centers when counseling elderly patients on the expected daily functional benefits of this device.  相似文献   
87.
Cisplatin is one of the most active single agents in the treatment of advanced cancer of the cervix. The concurrent administration of the nephroprotective agent, sodium thiosulfate, has enabled exploitation of the therapeutic potential of cisplatin. To explore the role of cisplatin dose intensity in the treatment of patients with cancer of the uterine cervix, patients with persistent/recurrent measurable disease were treated with cisplatin at 200 mg/m2 as a 2-hr infusion with sodium thiosulfate given at 3.3 g/m2 1 hr prior to cisplatin and 6.6 g/m2 during the cisplatin infusion. Treatment was repeated monthly. Due to the known cumulative toxicity of cisplatin, treatment beyond two cycles (400 mg/m2) was given only to those patients who had at least demonstrated a PR. Audiologic evaluation was done prior to each cycle of treatment. Eleven patients were entered with a median age of 43 years (range, 25-57), a median KPS of 80% (range, 60-90%), and nine epidermoid and two adenocarcinoma, and all patients had received previous pelvic irradiation. Twenty-eight cycles of treatment were given: 1, five cycles; 3, three cycles; 7, two cycles. No greater than or equal to 3+ hematologic, neurologic, or renal toxicity was demonstrated. Ototoxicity was demonstrated in the mild to moderate hearing loss range (3000-8000 Hz). The greatest threshold shift occurred after the first course of cisplatin. There were three PRs with a maximum duration of 4 months. Due to the significant toxicities encountered, the low response rate, and the limited duration of responses, this trial was closed early to accrual.  相似文献   
88.
There is evidence that cervical adenocarcinoma is increasing in incidence, particularly in young women. In order to assess the possible role of human papillomaviruses in cervical glandular oncogenesis, 16 cases of invasive adenocarcinoma and eight cases of adenocarcinoma in situ have been examined by in situ DNA hybridization using biotinylated probes to human papillomavirus types 6, 11, 16, 18, and 31, and assessed by polymerase chain reaction analysis for human papillomavirus types 11, 16, and 18 sequences. Of the invasive adenocarcinomas, four of 16 contained human papillomavirus type 16 sequences and one of 16 contained type 18 sequences as assessed by polymerase chain reaction analysis. Five of eight cases of adenocarcinoma in situ contained human papillomavirus type 16 sequences by polymerase chain reaction analysis. Only one invasive adenocarcinoma and one case of adenocarcinoma in situ showed a positive in situ hybridization signal. The low rate of carriage of the human papillomavirus sequences examined suggests that these viral types may not play a major role in cervical glandular neoplasia.  相似文献   
89.
The serum erythropoietin (EPO) concentration in patients with myelodysplasia (MDS) varies widely at similar hemoglobin concentrations, although the reasons for this variation are unclear. We have studied the pharmacokinetics of an i.v. bolus of recombinant human EPO in ten subjects with myelodysplasia. Basal serum EPO concentration varied from 210 to 5984 mU/ml. Plasma half-time clearance (t1/2) varied from 3.9 to 20.0 h. A significant positive correlation was found between t1/2 and basal EPO concentration. An increase in immature peripheral blood reticulocytes was found on days 1 and 2 after EPO treatment; this may represent either an effect on hemopoiesis or on reticulocyte release from the bone marrow.  相似文献   
90.
To gain more insight into the complex pulmonary interactions of endothelins (ET), we studied airway and vascular responses to endothelins in isolated perfused rat lungs in the presence of the novel ETB-receptor antagonist BQ788. In particular we focused on airway responses and on prostacyclin release. The effectiveness of BQ788 in our system was shown by its ability to concentration-dependently prevent vasoconstriction (IC50 0.1μM), bronchoconstriction (IC50 0.1μM) and prostacyclin production (IC50<0.1μM) induced by the ETB-receptor agonist IRL1620 (1nmol). Airway responses to ET-1: ET-1-induced bronchoconstriction was aggravated by BQ123 (1 or 8μM), while BQ788 pretreatment (1 or 8μM) showed no significant effect. Simultaneous treatment with 8μM BQ123 and BQ788 attenuated the ET-1-induced bronchoconstriction. Vascular responses to ET-1: ET-1 (1nmol)-induced vasoconstriction was potentiated by BQ788 (1 or 8μM), but attenuated by the ETA-receptor antagonist BQ123 (1μM). In the presence of BQ788 diminished amounts of the stable prostacyclin metabolite 6-keto-PGF were detected in the perfusate. Simultaneous treatment with 8μM BQ123 and BQ788 completely prevented the ET-1-induced vasoconstriction. Conclusions: Both ETA- and ETB-receptors contribute to ET-1-induced vasoconstriction and bronchoconstriction. The ET-1-induced vasoconstriction is attenuated by stimulation of ETB-receptors, a response that is partly mediated by prostacyclin. Due to the mutual interactions between ETA- and ETB-receptors, simultaneous inhibition of both receptors is required to prevent the deleterious effects of ET-1 on lung functions. Received: 17 October 1996 / Accepted: 16 May 1997  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