全文获取类型
收费全文 | 3809篇 |
免费 | 356篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 176篇 |
妇产科学 | 101篇 |
基础医学 | 516篇 |
口腔科学 | 170篇 |
临床医学 | 396篇 |
内科学 | 708篇 |
皮肤病学 | 87篇 |
神经病学 | 238篇 |
特种医学 | 476篇 |
外科学 | 452篇 |
综合类 | 63篇 |
一般理论 | 6篇 |
预防医学 | 315篇 |
眼科学 | 54篇 |
药学 | 209篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 212篇 |
出版年
2022年 | 18篇 |
2021年 | 48篇 |
2020年 | 27篇 |
2019年 | 55篇 |
2018年 | 68篇 |
2017年 | 61篇 |
2016年 | 60篇 |
2015年 | 74篇 |
2014年 | 74篇 |
2013年 | 121篇 |
2012年 | 109篇 |
2011年 | 120篇 |
2010年 | 113篇 |
2009年 | 134篇 |
2008年 | 118篇 |
2007年 | 141篇 |
2006年 | 125篇 |
2005年 | 126篇 |
2004年 | 105篇 |
2003年 | 101篇 |
2002年 | 94篇 |
2001年 | 91篇 |
2000年 | 91篇 |
1999年 | 95篇 |
1998年 | 126篇 |
1997年 | 135篇 |
1996年 | 130篇 |
1995年 | 93篇 |
1994年 | 103篇 |
1993年 | 119篇 |
1992年 | 102篇 |
1991年 | 77篇 |
1990年 | 87篇 |
1989年 | 103篇 |
1988年 | 87篇 |
1987年 | 76篇 |
1986年 | 73篇 |
1985年 | 90篇 |
1984年 | 67篇 |
1983年 | 43篇 |
1982年 | 43篇 |
1981年 | 54篇 |
1980年 | 36篇 |
1979年 | 41篇 |
1978年 | 19篇 |
1977年 | 34篇 |
1976年 | 30篇 |
1975年 | 24篇 |
1971年 | 20篇 |
1970年 | 15篇 |
排序方式: 共有4190条查询结果,搜索用时 31 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.
5.
Neuropharmacology and Drug Interactions in Clinical Practice 总被引:2,自引:2,他引:0
Nina M. Graves 《Epilepsia》1995,36(S2):S27-S33
Summary: Absorption, distribution, and clearance are key pharmacokinetic principles. These parameters can be highly variable among patients and among compounds, and are factors that must be considered in the wide variability in response to medications. Current antiepileptic drugs (AEDs) present many challenges in their administration. However, understanding and utilizing pharmacokinetic principles can assist the clinician in the appropriate optimization of AEds. 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.
W. Demark-Wahnefried J. McClelland M. K. Campbell K. Hoben J. Lashley C. Graves B. Motsinger B. K. Rimer 《Journal of the National Medical Association》1998,90(4):197-202
African Americans are at increased risk for cancer and represent an important target population for programs such as Healthy People 2000, the Cancer Information Service (CIS), and the 5 a Day for Better Health Initiative. Yet, awareness of such programs among rural blacks is unknown. This study assessed awareness of these programs and determined related knowledge and beliefs among rural African Americans. It was undertaken as part of the baseline survey for the Black Churches United for Better Health project, a National Cancer Institute-funded initiative. A minority of respondents (n = 3737) demonstrated name recognition of Healthy People 2000 (23.4%), the CIS (42.4%), and the 5 a Day Program (40.7%). Far fewer (7.4%) were able to correctly identify the recommended daily number of servings of fruits and vegetables. Reported family history of cancer was associated with a greater tendency believe that eating more fruits and vegetables can prevent disease. These findings underscore the need for efforts to reach the rural black community with culturally sensitive and stage appropriate cancer prevention messages. Knowledge of family history of cancer may play an important role in targeting subgroups and delivering effective cancer prevention messages. 相似文献
8.
Simultaneous assay of felbamate plus carbamazepine, phenytoin, and their metabolites by liquid chromatography with mobile phase optimization 总被引:1,自引:0,他引:1
Felbamate is an investigational antiepileptic drug (AED) in clinical trials. A high-performance liquid chromatographic method for the simultaneous analysis of felbamate, phenytoin (PHT), 5-(p-hydroxyphenyl)-5-phenylhydantoin, carbamazepine (CBZ), carbamazepine-10,11-epoxide, and carbamazepine-10,11-diol in serum was developed by a mobile phase optimization technique. Capacity factors for the compounds of interest and 12 other AEDs and metabolites were determined with mixtures of methanol, acetonitrile, or tetrahydrofuran and a 0.01 M ammonium phosphate buffer, pH 6.5, on a reversed-phase C8 column. An optimized mobile phase composition was determined that could separate the compounds of interest and three internal standards in less than 15 min. Serum was extracted with CH2Cl2/ethyl acetate (2:1) after addition of three internal standards. The method was validated for within-day and between-day precision and accuracy for the six compounds. Coefficients of variation were generally less than 10% at all concentrations and less than 5% in the typical therapeutic range for each compound. The lower limit of detection was estimated at 0.2 micrograms/ml for CBZ and its metabolites and 0.5 micrograms/ml for felbamate and PHT. For felbamate, the lowest point on the standard curve was 1.88 micrograms/ml with a between-day variability of 10.3%. The assay was used to determine the serum concentrations of PHT and CBZ and its metabolites in a subject before, during, and after felbamate therapy. 相似文献
9.
10.
L Graves D J Stechschulte D C Morris B P Lukert 《Journal of bone and mineral research》1990,5(11):1113-1119
A 59-year-old male presented with systemic mastocytosis with extensive skeletal involvement resulting in vertebral compression fractures and bone pain. Histomorphometric analysis of bone revealed increased mast cells, elevated static parameters of bone resorption, and low bone formation. Serum calcium, phosphorus, and alkaline phosphatase were normal; however, serum 1,25-dihydroxyvitamin D3 and osteocalcin levels were low. Histamine levels in plasma and urine were elevated. Following therapy with ketotifen, the patient had resolution of bone pain along with decreased flushing and pruritus. Elevated plasma and urine histamine levels normalized, as did 1,25-dihydroxyvitamin D3 and osteocalcin levels. Indices of low bone formation improved on therapy. Eroded surfaces improved but remained elevated. This case is the first demonstration that bone symptoms and histomorphometric change in systemic mastocytosis are reversed with inhibition of mast cell degranulation. The role of mast cells and their products in bone metabolism is poorly understood, but the therapy of bone disease in systemic mastocytosis should include inhibition of the release of mast cell products along with the use of histamine antagonist. 相似文献