全文获取类型
收费全文 | 3650篇 |
免费 | 278篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 272篇 |
妇产科学 | 81篇 |
基础医学 | 396篇 |
口腔科学 | 109篇 |
临床医学 | 305篇 |
内科学 | 801篇 |
皮肤病学 | 76篇 |
神经病学 | 181篇 |
特种医学 | 472篇 |
外国民族医学 | 1篇 |
外科学 | 519篇 |
综合类 | 70篇 |
预防医学 | 281篇 |
眼科学 | 33篇 |
药学 | 144篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 215篇 |
出版年
2023年 | 15篇 |
2022年 | 19篇 |
2021年 | 62篇 |
2020年 | 45篇 |
2019年 | 65篇 |
2018年 | 88篇 |
2017年 | 70篇 |
2016年 | 71篇 |
2015年 | 65篇 |
2014年 | 78篇 |
2013年 | 117篇 |
2012年 | 125篇 |
2011年 | 150篇 |
2010年 | 119篇 |
2009年 | 158篇 |
2008年 | 147篇 |
2007年 | 148篇 |
2006年 | 143篇 |
2005年 | 125篇 |
2004年 | 103篇 |
2003年 | 130篇 |
2002年 | 97篇 |
2001年 | 98篇 |
2000年 | 92篇 |
1999年 | 91篇 |
1998年 | 125篇 |
1997年 | 139篇 |
1996年 | 136篇 |
1995年 | 93篇 |
1994年 | 100篇 |
1993年 | 110篇 |
1992年 | 62篇 |
1991年 | 71篇 |
1990年 | 49篇 |
1989年 | 77篇 |
1988年 | 75篇 |
1987年 | 57篇 |
1986年 | 60篇 |
1985年 | 47篇 |
1984年 | 30篇 |
1983年 | 29篇 |
1982年 | 35篇 |
1981年 | 46篇 |
1980年 | 35篇 |
1979年 | 29篇 |
1978年 | 14篇 |
1977年 | 31篇 |
1976年 | 24篇 |
1975年 | 10篇 |
1967年 | 10篇 |
排序方式: 共有3963条查询结果,搜索用时 15 毫秒
1.
Maren T Scheuner William C Whitworth Henraya McGruder Paula W Yoon Muin J Khoury 《Genetics in medicine》2006,8(8):525-531
PURPOSE: We examined the performance of a familial risk assessment method that stratifies risk for early-onset coronary heart disease by considering the number of relatives with coronary disease, degree of relationship, lineage, and age at diagnosis. METHODS: By using data from the HealthStyles 2003 survey, we assessed the associations between familial risk and early-onset coronary heart disease, diabetes, hypercholesterolemia, hypertension, and obesity. By using area under the curve statistics, we evaluated the discriminatory ability of various risk assessment models. RESULTS: Of 4,035 respondents, 60% were female and 72% were white, with a mean age of 48.8 years. After adjustment for demographics, strong and moderate risk were significantly associated with approximately a five- and twofold risk of early-onset coronary disease, respectively. After adjustment for demographics and personal history of cardiovascular disease, strong familial risk was also significantly associated with diabetes, hypercholesterolemia, hypertension, and obesity. A risk assessment model that included familial risk, demographics, and personal history of diabetes, hypercholesterolemia, hypertension, and obesity was most optimal with an area under the curve statistic of 87.2% CONCLUSIONS: Familial risk assessment can stratify risk for early-onset coronary heart disease. Several conditions associated with increased familial risk can be prevented. These results have important implications for risk assessment and risk-reducing interventions. 相似文献
2.
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
3.
4.
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
5.
The modulation of co-stimulatory pathways represents a novel therapeutic strategy to regulate autoimmune diseases. Auto-reactive
CD4+ T cells play a critical role in initiating the immune response leading to inflammation and autoimmune diseases. Blocking
co-stimulatory signals prevents T-cell activation, thus diminishing autoimmune responses and possibly preventing the progression
of autoimmune disease. Blockade of several co-stimulatory pathways has been investigated in animal models and has led to clinical
trials testing specific blocking agents in humans. In this review we will describe the role of co-stimulatory pathways, primarily
the CD28-B7 pathway, in autoimmune diseases, and we will present in vivo and in vitro studies supporting the efficacy of co-stimulation blockade in animal models of autoimmune disease. Finally, we will discuss
the clinical therapeutic efficacy of blocking monoclonal antibodies in preventing or reducing auto-antigen driven T-cell activation
in humans with particular attention to the CD28/B7 pathway. Inhibiting co-stimulatory molecule interactions by using monoclonal
antibodies seems to be an original approach to regulate autoimmune diseases in humans. 相似文献
6.
M J Khoury W Stewart A Weinstein S Panny P Lindsay M Eisenberg 《Journal of clinical epidemiology》1988,41(1):15-20
Although most teratogens are suspected to act early in the first trimester of pregnancy, birth defects monitoring programs and etiologic studies usually use residence at birth as a proxy measure for residence in the first trimester in searching for environmental teratogens. Because of the high mobility of the U.S. population, residence misclassification can potentially alter inferences concerning environmental teratogens. To evaluate this potential bias, data from the population-based Maryland Birth Defects Reporting and Information System were analyzed. In 1984, the system ascertained 295 infants with one or more of 12 sentinel defects. Of these cases, 59 (20%) mothers reported they have changed address between the time of conception and the time of birth, and 22 have moved to a different county. The residential mobility rate varied by demographic variables and was highest among white women, in the age group 20-24 years. If residence at birth is used as a screening test for residence at conception, it can be shown that in the presence of an environmental teratogenic exposure, misclassification of exposure increases with increasing mobility rate, and population exposure frequency. Such misclassification tends to weaken associations between residence and birth defects and may lead to missing environmental teratogens. This analysis emphasizes the need to use residence information early in pregnancy rather than exclusively at birth. 相似文献
7.
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
8.
9.
10.
O M Dajani F F Haddad H A Hajj R E Sfeir G S Khoury 《European journal of vascular surgery》1988,2(5):293-296
Over a 10-year-period extending from January 1976 to September 1986, 800 peripheral vascular injuries were surgically treated at the American University of Beirut Medical Centre. Of these, 150 were operated on because of injury to the femoral vessels. Bullets were the commonest wounding agents (60% of cases). Thirty-seven patients had a femoral artery injury, 27 a femoral vein injury and 86 combined femoral artery and vein damage. Twenty-three per cent of the patients had an associated fracture of the femur. Patients with fractures had an 11% amputation rate compared with 1% for those without fractures. Our data reveals the importance of venous reconstruction in the presence of an arterial injury instead of its ligation (P less than 0.05), particularly when there is an associated fracture of the femur. Thirty-seven per cent of patients were in shock on admission (systolic BP 90 mmHg). The amputation rate in these patients was 6.8% in contrast to 1% in the haemodynamically stable group (P less than 0.05). The overall amputation rate was 3.3%. Complications occurred in 36.6% of patients and the mortality was 4.0%. 相似文献