全文获取类型
收费全文 | 50346篇 |
免费 | 2861篇 |
国内免费 | 240篇 |
专业分类
耳鼻咽喉 | 642篇 |
儿科学 | 1155篇 |
妇产科学 | 1028篇 |
基础医学 | 6606篇 |
口腔科学 | 2539篇 |
临床医学 | 3757篇 |
内科学 | 12731篇 |
皮肤病学 | 1164篇 |
神经病学 | 4066篇 |
特种医学 | 1080篇 |
外科学 | 7051篇 |
综合类 | 288篇 |
一般理论 | 11篇 |
预防医学 | 4506篇 |
眼科学 | 921篇 |
药学 | 3022篇 |
1篇 | |
中国医学 | 300篇 |
肿瘤学 | 2579篇 |
出版年
2023年 | 421篇 |
2022年 | 870篇 |
2021年 | 1974篇 |
2020年 | 1064篇 |
2019年 | 1652篇 |
2018年 | 2049篇 |
2017年 | 1263篇 |
2016年 | 1340篇 |
2015年 | 1585篇 |
2014年 | 2120篇 |
2013年 | 2605篇 |
2012年 | 4073篇 |
2011年 | 4357篇 |
2010年 | 2327篇 |
2009年 | 2024篇 |
2008年 | 3270篇 |
2007年 | 3174篇 |
2006年 | 2922篇 |
2005年 | 2743篇 |
2004年 | 2381篇 |
2003年 | 2038篇 |
2002年 | 1823篇 |
2001年 | 632篇 |
2000年 | 584篇 |
1999年 | 564篇 |
1998年 | 339篇 |
1997年 | 267篇 |
1996年 | 240篇 |
1995年 | 177篇 |
1994年 | 175篇 |
1993年 | 123篇 |
1992年 | 257篇 |
1991年 | 223篇 |
1990年 | 171篇 |
1989年 | 148篇 |
1988年 | 136篇 |
1987年 | 106篇 |
1986年 | 140篇 |
1985年 | 109篇 |
1984年 | 106篇 |
1983年 | 78篇 |
1982年 | 82篇 |
1981年 | 67篇 |
1980年 | 65篇 |
1979年 | 61篇 |
1978年 | 48篇 |
1977年 | 38篇 |
1976年 | 46篇 |
1974年 | 55篇 |
1973年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
A D Hess R J Jones L E Morris S J Noga G B Vogelsang G W Santos 《Human immunology》1992,34(3):219-224
Autologous bone marrow transplantation (BMT) is a therapeutic option for the treatment of lymphohematopoietic malignancies and solid tumors. Despite the intensive cytoreductive therapy, however, the rates of tumor recurrence after autologous BMT remain unacceptably high. Current studies suggest that the administration of cyclosporine (CsA) disrupts the reconstitution of self-tolerance following autologous BMT leading to the induction of an autoimmune graft-versus-host disease (GVHD). Studies in a rat tumor model and preliminary clinical trials suggest that this autoimmune or autologous GVHD provides a significant antitumor effect. Moreover, the antitumor effect of autologous GVHD can be enhanced by administration of gamma-interferon, which upregulates the antigen recognized by the autoreactive effector cells of autologous GVHD. These studies indicate that the induction of an autoimmune GVHD after autologous BMT may be a promising immunotherapeutic approach for treatment of certain neoplastic diseases. 相似文献
112.
Renal dysfunction after myocardial revascularization. 总被引:5,自引:0,他引:5
Pedro E Antunes David Prieto J Ferr?o de Oliveira Manuel J Antunes 《European journal of cardio-thoracic surgery》2004,25(4):597-604
OBJECTIVES: In this study, we evaluate the incidence of and analyse the pre and intraoperative risk factors for the development of postoperative renal dysfunction (PRD), and the impact of such an event on perioperative mortality and on hospital length of stay. In addition, we sought to investigate the influence of a mildly increased serum creatinine (1.3-2.0 mg/dl) on perioperative mortality and morbidity. METHODS: The study included 2445 consecutive patients who had no pre-existing renal disease (creatinine or=2.1 mg/dl with a preoperative-to-postoperative increase >or=0.9 mg/dl. Univariate and multivariate analyses were performed where appropriate. RESULTS: Global 30-day mortality was 0.7%. The incidence of PRD was 5.6% (136 patients). Mortality for patients who experienced PRD was 8.8 vs. 0.1% for patients who did not (P<0.001). PRD increased the length of hospital stay by 3.4 days (7.6 vs. 11.0 days; P<0.001), and patients who needed haemodialysis (11%) had a perioperative mortality of 33.3% and a mean hospital length of stay of 16 days. Multivariable logistic regression identified the following variables as independent predictors of PRD: age (P=0.017; odds ratio (OR) 1.3 per 10 years), angina class III/IV (P=0.003; OR 1.7); cardiopulmonary bypass time (P=0.007; OR 1.01 per minute); preoperative serum creatinine levels: group 1 (1.3-1.6 mg/dl (P<0.001; OR 5.5)) and group 2 (1.7-2.0 mg/dl (P<0.001; OR 14.2)). Finally, a mild elevation of the preoperative creatinine level (1.3-2.0 mg/dl) increased significantly the probability of perioperative mortality, low cardiac output, haemodialysis and prolonged hospital stay. CONCLUSIONS: Although the likelihood of PRD in patients without pre-existing renal dysfunction is relatively low, it dramatically increases mortality, morbidity and length of stay after CABG. Mildly elevated (>1.2 mg/dl) preoperative serum creatinine level significantly increases the perioperative mortality and morbidity. 相似文献
113.
Transcranial magnetic stimulation over dorsolateral prefrontal cortex in Parkinson's disease. 总被引:4,自引:0,他引:4
OBJECTIVE: Several studies have shown that repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) is effective in the treatment of depression in patients with Parkinson disease (PD). However, since research into the effect of this type of rTMS regime on motor function is limited, we studied the effect of rTMS over the DLPFC on the motor functions in PD patients. METHODS: Thirteen patients were randomly assigned into 2 groups, one receiving real-rTMS (90% of resting motor threshold, 10 Hz, 450 pulses-day for 10 consecutive days) over the DLPFC contralateral to the more affected side, and the other group receiving sham-rTMS. Assessment included a clinical motor evaluation using part III of the Unified Parkinson's Disease Rating Scale (UPDRS), and several motor tasks. The UPDRS was applied before and after 10 days of rTMS. Finger tapping, reach movement, grip movement and gait were measured in each session before and after the rTMS over the 10 day period. RESULTS: Statistical analysis (ANOVA for repeated measures; group *day *side *rTMS) only showed a significant effect for finger tapping, reach movement and gait for the factor day. No significant change was reported for the UPDRS in any group. CONCLUSIONS: Application of rTMS over the DLPFC as a 10 day course had no significant effect on motor functions and clinical motor status, and the improvement in performance of motor tasks can be attributed to the effects of practice. SIGNIFICANCE: rTMS over the DLPFC did not lead to any motor improvement in PD patients. 相似文献
114.
Nelson Wolosker Guilherme Yazbek José Ribas Milanez de Campos Paulo Kauffman Augusto Ishy Pedro Puech-Leão 《Clinical autonomic research》2007,17(3):172-176
Background Sympathectomy is the treatment of choice for primary hyperhidrosis. One curious occurrence that is difficult to explain from
an anatomophysiological point of view in cases of video-assisted thoracoscopic sympathectomy (VATS) for the treatment of palmar
hyperhidrosis (PH) is the observed improvement in plantar hyperhidrosis (PLH). Nevertheless, current reports on VATS rarely
describe the effect on PLH or just give superficial data. The aim of this study was to prospectively investigate, how surgery
affects PLH in patients with PH and PLH over one-year period.
Methods From May 2003 to January 2004, 70 consecutive patients with combined PH and PLH underwent VATS at the T2, T3, or T4 ganglion
level (47 women and 23 men, with mean age of 23 years).
Results Immediately after the operation, all the patients said they were free from PH episodes, except for two patients (2.8%) who
suffered from continued PH. Compensatory hyperhidrosis (CH) of various degrees was observed in 58 (90.6%) patients after one
year. Only 13 (20.3%) suffered from severe CH. There was a great initial improvement in PLH in 50% of the cases, followed
by progressive regression, such that only 23.4% still presented that improvement after one year. The number of cases without
overall improvement increased progressively (from 17.1% to 37.5%) and the numbers with slight improvement remained stable
(32.9–39.1%). Of the 24 patients with no improvement after one year, 6 patients graded plantar sweating worse.
Conclusion Patients with PH and PLH who undergo VATS to treat their PH present a good initial improvement in PLH that reduces to a lower
level of improvement after the one-year period. 相似文献
115.
Immunophenotypic, genomic and clinical characteristics of blast crisis of chronic myelogenous leukaemia 总被引:1,自引:0,他引:1
J. M. Hernández R. González-Sarmiento C. Martin M. González I. Sánchez J. Corral A. Orfao M. C. Canizo J. F. san Miguel A. López-borrasca 《British journal of haematology》1991,79(3):408-414
We have studied phenotypic and clinical features in a consecutive series of 45 patients with chronic myelogenous leukaemia (CML) in blast crisis (BC). In addition, in 22 of these patients we have analysed the genotypic characteristics including immunoglobulin, T-cell receptor (TCR) and major breakpoint cluster region (M-bcr) gene organization. The granulomonocytic and megakaryoblastic lineages are the most commonly involved in these BC of CML (33% and 33% of cases, respectively); only 18% of our cases displayed a lymphoid phenotype. Moreover, both morphological and immunophenotypic studies revealed the frequent coexistence of two or three cell populations, especially when the megakaryoblast component is involved. The lymphoid BC displayed the highest incidence of complete remissions although this was not associated with a longer survival. Only minor differences between the different myeloid subgroups were observed. Immunoglobulin heavy chain (IgH) gene rearrangement was found in five of the six lymphoid BC and in one myeloid BC. Only one case showed k light chain gene rearrangement. In all but one myeloid BC the TCR-beta gene was in germline configuration. The TCR-gamma gene was rearranged in all lymphoid and one myeloid BC, while TCR-delta gene rearrangement was detected in 67% and 16% of the lymphoid and myeloid BC, respectively. Most of the lymphoid BC (4/5) had the M-bcr breakpoint in subregion 3, while the myeloid BC had the breakpoint either in subregion 2 or 3. No differences between the different myeloid phenotypic subgroups were observed in relation to breakpoint. 相似文献
116.
117.
118.
119.
The inhibitory action of the major constituent of Sebastiania schottiana (Euphorbiaceae), 2-hydroxy-4,6-dimethoxyacetophenone (xanthoxyline) on contractions induced by agonists and electrical stimulation of smooth and cardiac muscle preparations was analysed. Xanthoxyline (30 to 300 microM) inhibited contractions of the rat uterus, guinea-pig ileum, and urinary bladder induced by several agonists in a non-competitive, non-selective, concentration-related manner, with the IC50's ranging between 47 and 190 microM. Twitches evoked by electrical-stimulation of strips of guinea-pig longitudinal ileum, urinary bladder, dog ureter, and rat left atrium were also inhibited dose-dependently by cumulative additions of xanthoxyline (IC50's between 50 and 480 microM). Xanthoxyline was found to be a potent inhibitor of spontaneous contractions of the circular smooth muscle layer of the dog ureter, yielding an IC50 of 54 microM. Repeated washing of all preparations completely reversed the inhibitory effects of xanthoxyline. Therefore, it appears that xanthoxyline induces a direct and non-selective inhibition of contractions triggered by agonists or electrical stimulation of smooth and cardiac muscle preparations. The elucidation of the mechanism(s) by which xanthoxyline induced muscle relaxation requires further investigations. 相似文献
120.