全文获取类型
收费全文 | 4232篇 |
免费 | 361篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 197篇 |
妇产科学 | 113篇 |
基础医学 | 480篇 |
口腔科学 | 220篇 |
临床医学 | 483篇 |
内科学 | 905篇 |
皮肤病学 | 54篇 |
神经病学 | 243篇 |
特种医学 | 422篇 |
外科学 | 460篇 |
综合类 | 50篇 |
一般理论 | 3篇 |
预防医学 | 363篇 |
眼科学 | 67篇 |
药学 | 303篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 238篇 |
出版年
2021年 | 46篇 |
2020年 | 39篇 |
2019年 | 45篇 |
2018年 | 63篇 |
2017年 | 60篇 |
2016年 | 66篇 |
2015年 | 85篇 |
2014年 | 93篇 |
2013年 | 140篇 |
2012年 | 122篇 |
2011年 | 136篇 |
2010年 | 109篇 |
2009年 | 165篇 |
2008年 | 153篇 |
2007年 | 154篇 |
2006年 | 157篇 |
2005年 | 136篇 |
2004年 | 130篇 |
2003年 | 140篇 |
2002年 | 120篇 |
2001年 | 105篇 |
2000年 | 114篇 |
1999年 | 94篇 |
1998年 | 139篇 |
1997年 | 145篇 |
1996年 | 142篇 |
1995年 | 95篇 |
1994年 | 101篇 |
1993年 | 128篇 |
1992年 | 91篇 |
1991年 | 93篇 |
1990年 | 90篇 |
1989年 | 104篇 |
1988年 | 117篇 |
1987年 | 90篇 |
1986年 | 92篇 |
1985年 | 95篇 |
1984年 | 60篇 |
1983年 | 40篇 |
1982年 | 43篇 |
1981年 | 58篇 |
1980年 | 36篇 |
1979年 | 46篇 |
1978年 | 35篇 |
1977年 | 39篇 |
1976年 | 41篇 |
1975年 | 27篇 |
1974年 | 18篇 |
1973年 | 20篇 |
1970年 | 20篇 |
排序方式: 共有4620条查询结果,搜索用时 31 毫秒
1.
2.
3.
K U Chu S Higashide B M Evers S Rajaraman J Ishizuka C M Townsend Jr J C Thompson 《Annals of surgery》1994,220(4):570-577
OBJECTIVE: The authors determined whether bombesin could improve survival from methotrexate (MTX)-induced enterocolitis. SUMMARY BACKGROUND DATA: Bombesin prevents gut mucosal atrophy, which is produced by feeding rats an elemental diet. Administration of MTX produces a lethal enterocolitis in rats fed an elemental diet. METHODS: On treatment day 0, 60 rats were divided randomly into three groups and fed an elemental diet (Vivonex TEN, Sandoz, Minneapolis, MN) as the only source of nutrition. Groups were subdivided further to receive either saline or bombesin (10 micrograms/kg, subcutaneously, three times a day) beginning either on day 0 or day 14. Methotrexate (20 mg/kg, intraperitoneally) was given to all rats 14 days after the start of an elemental diet. RESULTS: Bombesin prevented the mucosal atrophy in the ileum produced by the elemental diet and significantly decreased mortality in rats given MTX (whether given as a pretreatment or at the time of MTX administration). CONCLUSION: Bombesin significantly improved survival in a lethal model of MTX-induced enterocolitis, possibly by maintaining gut mucosal structure. Administration of bombesin to patients receiving chemotherapy may be clinically useful in preventing the severe enterocolitis induced by various chemotherapeutic agents. 相似文献
4.
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
5.
6.
J W Rose H Lorberboum-Galski D Fitzgerald R McCarron K E Hill J J Townsend I Pastan 《Journal of neuroimmunology》1991,32(3):209-217
IL2-PE40 is a chimeric protein composed of human interleukin-2 (IL2) genetically fused to a modified form of Pseudomonas exotoxin lacking the cell recognition domain. IL2-PE40 is cytotoxic for IL2 receptor-bearing lymphocytes in culture and can inhibit activation of T cells in vivo. IL2-PE40 can significantly diminish antigen-stimulated proliferation of lymphocytes sensitized to myelin basic protein. Intraperitoneal administration of IL2-PE40 not only markedly inhibits the clinical manifestations of adoptively transferred relapsing experimental allergic encephalomyelitis but also dramatically reduces both inflammation and demyelination characteristic of the disease. 相似文献
7.
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
8.
By convention, establishing a physiologic role for a gut peptide requires demonstration of biologic activity that can be reproduced by exogenous administration of the peptide in amounts that yield plasma concentrations that are not higher than those found after a meal. We have tested the hypothesis that the combined action of two inhibitory peptides may lower the effective doses of each. We further hypothesize that combined peptide responses may be responsible for the action of peptide hormones that have been difficult to demonstrate as physiologically relevant mediators, when examined as independently acting substances. In conscious dogs prepared with chronic pancreatic cannulas, stimulated pancreatic exocrine secretions were depressed in a dose-related manner by intravenous infusions of calcitonin (CT) and calcitonin gene-related peptide (CGRP). Doses of 2.0 nmol/kg/hr of both CT and CGRP yielded maximal inhibition of stimulated secretions of both bicarbonate (greater than 85% inhibition) and protein (greater than 55% inhibition). The lowest effective dose for either CT or CGRP, given alone, was 0.75 nmol/kg/hr, but when infused simultaneously, each at the subthreshold dose of 0.50 nmol/kg/hr, significant inhibition of protein and bicarbonate secretion was achieved. Combined infusions of the submaximal dose of 0.75 nmol/kg/hr resulted in an enhanced inhibitory response. To prove that this effect is not simply combined activation of a common receptor, we tested peptide YY (0.1 to 0.5 nmol/kg/hr) combined with CGRP and obtained similar results. Because a meal simultaneously releases a large number of active peptides, we speculate that such potentiated responses do occur physiologically. Cooperative interaction with other agents may be the primary mode of action for certain gut peptides. 相似文献
9.
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
10.