全文获取类型
收费全文 | 4690篇 |
免费 | 264篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 202篇 |
妇产科学 | 83篇 |
基础医学 | 432篇 |
口腔科学 | 84篇 |
临床医学 | 520篇 |
内科学 | 946篇 |
皮肤病学 | 59篇 |
神经病学 | 518篇 |
特种医学 | 429篇 |
外科学 | 471篇 |
综合类 | 70篇 |
一般理论 | 5篇 |
预防医学 | 297篇 |
眼科学 | 291篇 |
药学 | 316篇 |
1篇 | |
中国医学 | 3篇 |
肿瘤学 | 226篇 |
出版年
2022年 | 31篇 |
2021年 | 62篇 |
2020年 | 39篇 |
2019年 | 42篇 |
2018年 | 71篇 |
2017年 | 61篇 |
2016年 | 69篇 |
2015年 | 83篇 |
2014年 | 103篇 |
2013年 | 173篇 |
2012年 | 155篇 |
2011年 | 174篇 |
2010年 | 133篇 |
2009年 | 163篇 |
2008年 | 150篇 |
2007年 | 174篇 |
2006年 | 180篇 |
2005年 | 156篇 |
2004年 | 119篇 |
2003年 | 149篇 |
2002年 | 148篇 |
2001年 | 123篇 |
2000年 | 144篇 |
1999年 | 119篇 |
1998年 | 128篇 |
1997年 | 145篇 |
1996年 | 132篇 |
1995年 | 100篇 |
1994年 | 104篇 |
1993年 | 110篇 |
1992年 | 90篇 |
1991年 | 65篇 |
1990年 | 67篇 |
1989年 | 93篇 |
1988年 | 81篇 |
1987年 | 74篇 |
1986年 | 90篇 |
1985年 | 85篇 |
1984年 | 60篇 |
1983年 | 54篇 |
1982年 | 40篇 |
1981年 | 49篇 |
1980年 | 39篇 |
1979年 | 49篇 |
1978年 | 29篇 |
1977年 | 36篇 |
1976年 | 30篇 |
1975年 | 29篇 |
1935年 | 22篇 |
1933年 | 26篇 |
排序方式: 共有4985条查询结果,搜索用时 15 毫秒
1.
Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight. 相似文献
2.
ME BURGE AM JOSHUA CM McNEIL R HUI MJ BOYER R ABRAHAM 《Asia-Pacific Journal of Clinical Oncology》2005,1(1):47-52
Background: Pemetrexed and cisplatin have recently been shown to significantly improve survival compared with cisplatin alone. However, there are only limited data reflecting teaching hospital experience outside a clinical trial. Pemetrexed has only been available in Australia on a restricted basis since 2002. We reviewed our experience of patients treated on the Australian ‘Special Access Scheme’ at three major thoracic oncology units. Methods: Charts were reviewed for all patients enrolled on the scheme. Data was extracted on age, World Health Organization (WHO) performance status, histology, prior therapy, time from diagnosis to starting pemetrexed, chemotherapy (pemetrexed alone or with a platinum), cycle number, response rate, actuarial progression‐free and overall survival. Doses were cisplatin 75 mg/m2 or carboplatin AUC = 5 and pemetrexed 500 mg/m2 every 21 days. Results: 52 patients (32 male and 20 female) were reviewed. Median age was 58 years and 88% were WHO 0–1. Histology included 54% epithelial, 17% biphasic (epithelial and sarcomatoid) and 21% undefined. The median time from diagnosis to administration of pemetrexed was 145 days. Sixty‐five percent had minimal surgical intervention with video assisted thoracoscopy, pleurodesis and biopsy, while 19% had received prior palliative radiation. Seventy‐one percent were chemotherapy naïve, the remaining 29% having received previous platinum and/or gemcitabine regimens. Twenty‐three percent had pemetrexed alone, 35% in combination with carboplatin and 42% with cisplatin. The median number of cycles was 4 (range 1–13). The response rate was 33%. No toxicity was observed in 20% grade 3–4 toxicity in 10% (majority nausea/vomiting). The median progression‐free and overall survival times from starting pemetrexed were 184 days and 298 days, respectively. Conclusions: Pemetrexed‐based regimens are safe and effective in a community setting in malignant mesothelioma. 相似文献
3.
4.
M C Post J G L M Luermans H W M Plokker W Budts 《Catheterization and cardiovascular interventions》2007,69(1):9-14
Migraine is a common neurological disorder with a great impact on the quality of life and social activities. The patent foramen ovale (PFO) is an intra-atrial right-to-left shunt with a prevalence of 25% in the general population. An increased prevalence is found in patients with migraine, especially in migraine with aura. Percutaneous PFO closure might decrease the prevalence of migraine. However, most of these observational studies were retrospective without a randomized design and the results need to be interpreted with caution. In this review we describe the association between PFO and migraine and the different pathophysiological hypotheses, which have been proposed to explain this relationship. 相似文献
5.
A new method is presented for studying mediator release in isolated peritoneal cells of the rat. Using a superfusion technique, cells can be maintained in a continuously cleared medium. Cells were stimulated with antigen, compound 48/80 or A23187 to characterize this preparation. In addition, inhibitory effects of theophylline, isoprenaline and cromoglycate on compound 48/80-induced histamine release were studied. We conclude that superfusion is a valid alternative to study mediator release from isolated peritoneal cells. 相似文献
6.
CM Reid M. Nelson P. Beckinsale P. Ryan LMH Wing LJ Beilin MA Brown GLR Jennings CI Johnston J. Marley JJ McNeil TO Morgan J. Shaw ID Steven MJ West 《Clinical and experimental pharmacology & physiology》1997,24(5):370-373
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial. 相似文献
7.
8.
Organic nitrates are used for the treatment of angina pectoris symptoms, acute coronary syndrome and for acute and chronic heart insufficiency. In spite of the proven effectiveness of organic nitrates for acute cases, long-term therapy is limited by to the development of tolerance. Recent animal experiments, as well as clinical data, show that an endothelial dysfunction is also induced, a disquieting point, especially considering the negative prognostic impact of endothelial dysfunction. Due to these side effects, the published guidelines of the American Heart Association and the American College of Physicians do not recommend the use of long-term nitrates, such as mono- and dinitrate, for the treatment of stable angina pectoris. Rather, if good left ventricular function is present the calcium antagonist amlodipine should be used. In cases of appreciably reduced left ventricular function, there is a current discussion, based on the recently published A-HeFT study, as to whether a combination therapy with organic nitrates and the effective arteriole dilator hydralazine is beneficial for patients with severe heart insufficiency. 相似文献
9.
Lawrence T. Post 《American journal of ophthalmology》1943,26(6):629-631
10.