全文获取类型
收费全文 | 6211篇 |
免费 | 405篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 135篇 |
妇产科学 | 127篇 |
基础医学 | 841篇 |
口腔科学 | 174篇 |
临床医学 | 565篇 |
内科学 | 1282篇 |
皮肤病学 | 69篇 |
神经病学 | 583篇 |
特种医学 | 364篇 |
外科学 | 729篇 |
综合类 | 13篇 |
一般理论 | 7篇 |
预防医学 | 584篇 |
眼科学 | 21篇 |
药学 | 562篇 |
中国医学 | 10篇 |
肿瘤学 | 539篇 |
出版年
2023年 | 27篇 |
2022年 | 31篇 |
2021年 | 94篇 |
2020年 | 67篇 |
2019年 | 107篇 |
2018年 | 114篇 |
2017年 | 103篇 |
2016年 | 106篇 |
2015年 | 122篇 |
2014年 | 212篇 |
2013年 | 280篇 |
2012年 | 470篇 |
2011年 | 511篇 |
2010年 | 287篇 |
2009年 | 262篇 |
2008年 | 446篇 |
2007年 | 514篇 |
2006年 | 429篇 |
2005年 | 432篇 |
2004年 | 370篇 |
2003年 | 352篇 |
2002年 | 319篇 |
2001年 | 104篇 |
2000年 | 69篇 |
1999年 | 86篇 |
1998年 | 85篇 |
1997年 | 71篇 |
1996年 | 64篇 |
1995年 | 57篇 |
1994年 | 48篇 |
1993年 | 64篇 |
1992年 | 39篇 |
1991年 | 36篇 |
1990年 | 39篇 |
1989年 | 31篇 |
1988年 | 22篇 |
1987年 | 15篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1974年 | 4篇 |
1972年 | 7篇 |
1970年 | 6篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有6634条查询结果,搜索用时 15 毫秒
11.
12.
13.
Plaque composition and its relationship with acknowledged shear stress patterns in coronary arteries. 总被引:2,自引:0,他引:2
14.
Lei Ding Christopher Wilke Bobby Xu Xiaoliang Xu Wim van Drongelen Michael Kohrman Bin He 《Journal of clinical neurophysiology》2007,24(2):130-136
SUMMARY: It is desirable to estimate epileptogenic zones with both location and extent information from noninvasive EEG. In the present study, the authors use a subspace source localization method (FINE), combined with a local thresholding technique, to achieve such tasks. The performance of this method was evaluated in interictal spikes from three pediatric patients with medically intractable partial epilepsy. The thresholded subspace correlation, which is obtained from FINE scanning, is a favorable marker, which implies the extents of current sources associated with epileptic activities. The findings were validated by comparing the results with invasive electrocorticographic (ECoG) recordings of interictal spike activity. The surgical resections in these three patients correlated well with the epileptogenic zones identified from both EEG sources and ECoG potential distributions. The value of the proposed noninvasive technique for estimating epileptiform activity was supported by satisfactory surgery outcomes. 相似文献
15.
Selma C. Tromp Geert Jan Tangelder Dick W. Slaaf Robert S. Reneman S. van Velzen Wim Engels E. van Breda M. G. A. oude Egbrink 《Pflügers Archiv : European journal of physiology》1998,436(2):255-261
The objective of the present study was to determine the role of mast cells and histamine in leukocyte-endothelium interactions
in mesenteric venules of four rat strains: Brown Norway, Lewis, Sprague-Dawley and Wistar. Intravital microscopy showed that
the mast cell stabilizer cromoglycate (5 mg/kg i.v. just before exteriorization of the mesentery) did not affect the baseline
level and velocity of leukocyte rolling in any of the four strains. This finding is in agreement with the observation that
cromoglycate pretreatment only slightly influenced mast cell degranulation in all strains except the Brown Norway. After mast
cell stabilization, only in Sprague-Dawley did topical administration of histamine (10–4 M) result in a significant increase in the level of leukocyte rolling and a decrease in the rolling velocity compared with
the time control. Histamine induced leukocyte adhesion only in the Brown Norway strain. In conclusion, the hypothesis presented
in other studies, that degranulation of mast cells, and more specifically the release of histamine, is of major importance
for the induction of leukocyte-endothelium interactions in rat mesenteric venules is not generally applicable; the present
study shows a clear strain dependency.
Received: 18 July 1997 / Received after revision: 17 November 1997 / Accepted: 13 March 1998 相似文献
16.
17.
Jan Paul Ouwens Wim van der Bij Thomas W van der Mark Albert Geertsma Do A Piers Wim J de Boer Gerard H Ko?ter 《The Journal of heart and lung transplantation》2004,23(1):115-121
BACKGROUND: A decrease in forced expiratory volume in 1 second (FEV(1)) as a diagnostic criterion for bronchiolitis obliterans syndrome (BOS) after single lung transplantation may be influenced significantly by the presence of the native lung. To quantify and to discriminate between the relative contribution of graft and native lung to the FEV(1), we retrospectively investigated the diagnostic value of combined FEV(1) measurements and ventilation scintigraphy in pulmonary dysfunction after single lung transplantation in 11 recipients with pulmonary vascular disease, 3 with obstructive lung disease, and 3 with restrictive lung disease. METHODS: We assessed function of the native lung and the graft, and subsequently calculated an adjusted grading of BOS by correcting routine FEV(1) measurements using linear interpolation of bi-annual lung ventilation scans. RESULTS: The contribution of the native lung to the total FEV(1) was slight (median, 9%) in recipients with obstructive disease compared with recipients with vascular (38%) or restrictive lung diseases (27%). Adjusted BOS grading was not useful in patients with obstructive disease. In the other patient groups, the onset of adjusted BOS Grade 1 and standard BOS Grade 1 was at a median of 220 days (range, 127-1146 days) and 836 days (184-3065 days), respectively. CONCLUSION: Ventilation scintigraphy is a useful adjunct in the (early) diagnosis of BOS in recipients of single lung transplants who have vascular and restrictive lung diseases. 相似文献
18.
Marco Treskes Ulbe Holwerda Leo G. J. Nijtmans Herbert M. Pinedo Wim J. F. van der Vijgh 《Cancer chemotherapy and pharmacology》1992,29(6):467-470
Summary The reversibility of cisplatin-protein interactions by the modulating agent WR2721, its active thiol-metabolite WR1065, and the symmetrical disulfide WR33278 was studied using the model compounds (Pt(diethylenetriammine) monofunctionally bound to the sulfur in glutathione (Pt(dien)SG) and Pt(diethylenetriammine) monofunctionally bound to the sulfur in S-methylglutathione (Pt(dien)SMeG). Both model compounds could be quantified by high-performance liquid chromatography (HPLC) with UV detection. The Pt-cysteine-like bond in Pt(dien)SG could not be reversed by any of the WR compounds or by the strong nucleophiles thiosulfate (TS) and diethyldithiocarbamate (DDTC). However, the Ptmethionine-like bond in Pt(dien)SMeG could be reversed by WR1065, although the reversal was slow (k2=0.142m
–1 s–1) as compared with that obtained using the modulating agents TS (k2=10.1m
–1 s–1) and DDTC (k2=3.66m
–1 s–1). WR2721 was hardly able to reverse the Pt-S bond in Pt(dien)SMeG (k2=0.00529m
–1 s–1), and WR33278 showed no capacity to do so. The activity ofcis-diamminedichloroplatinum(II) (CDDP)-inactivated fumarase was not appreciably restored by any of the WR compounds (16%, 7.7%, and 0 for 20mm WR1065, WR2721, and WR33278, respectively) in contrast to the strong nucleophile DDTC (61% for 2mm DDTC). These in vitro studies provide information at the molecular level that may explain why WR2721, in contrast to DDTC, does not provide protection against cisplatin-induced nephrotoxicity when it is given after platinum-containing chemotherapy. The results support the present clinical use of WR2721 prior to the administration of platinum compounds.This study was financially supported by the Netherlands Cancer Fund (grant IKA 87-12) and by US Bioscience 相似文献
19.
Efficacy and safety of xaliproden in amyotrophic lateral sclerosis: results of two phase III trials.
Vincent Meininger Gilbert Bensimon Walter R Bradley Benjamin Brooks Patrice Douillet Andrew A Eisen Lucette Lacomblez P Nigel Leigh Wim Robberecht 《Amyotrophic lateral sclerosis and other motor neuron disorders》2004,5(2):107-117
Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive and fatal motor neuron disease. We carried out two randomized, double-blind, placebo-controlled, multi-centre, multi-national studies with xaliproden (a drug with neurotrophic effect) to assess drug efficacy and safety at two doses. Patients with clinically probable or definite ALS of more than 6 months and less than 5 years duration were randomly assigned to placebo, 1 mg or 2 mg xaliproden orally once daily as monotherapy in Study 1 (n=867); or to the same regimen with addition of riluzole 50 mg bid background therapy in Study 2 (n=1210 patients). The two primary endpoints were defined as: 1. Time to death, tracheostomy, or permanent assisted ventilation (DTP), and 2. Time to vital capacity (VC)<50% or DTP before (log-rank test) and after adjustment using a Cox proportional hazard model for prespecified prognostic factors. Secondary endpoints were rates of change of various functional measures. In Study 1, primary outcome measures did not reach statistical significance. For the 2 mg group, for time to VC<50% analysis (without DTP) a significant 30% RRR was obtained (95% confidence interval [CI]: 8.46, P=0.009). In Study 2, no significant results were obtained. However, there was a trend in favour of add-on 1 mg dose xaliproden vs. placebo (RRR 15% [-6.31, ns] for time to VC<50%; RRR 12% [CI: -6.27, ns] for time to VC<50% or DTP). Adjusted RR ratios were consistently more favourable for the xaliproden groups. Tolerability was good, and dose-dependent side effects were largely associated with the serotonergic properties of xaliproden. An effect of xaliproden on functional parameters, especially VC, was noted. Although this effect did not reach statistical significance, xaliproden had a small effect on clinically noteworthy aspects of disease progression in ALS. 相似文献
20.
Determination of the growth fraction in monoclonal gammopathy with the monoclonal antibody Ki-67 总被引:3,自引:0,他引:3
Henk M. Lokhorst Saskia E. Boom Wim Terpstra Paul Roholl Johannes Gerdes Bert J. E. G. Bast 《British journal of haematology》1988,69(4):477-481
The monoclonal antibody Ki-67 reacts with a nuclear antigen that is present only in proliferating cells. The proportion of Ki-67 positive cells may therefore serve as a reliable measurement for the growth fraction in normal and neoplasmic cell populations. We have tested the significance of the MoAb Ki-67 in the classification of monoclonal gammopathy and compared the results with the plasma cell labelling index. In benign monoclonal gammopathy the percentage of Ki-67 positive plasma cells (median 1.6%) was significantly lower than in untreated multiple myeloma (median 9.6). Among the patients with more than 10% Ki-67 positive plasma cells there were some very short survivors. The largest growth fractions (median 41.8%) were found in patients with relapsing multiple myeloma indicating here a different growth pattern more resembling the high-grade lymphomas. A linear correlation between the proportion of Ki-67 positive plasma cells and the labelling index was not found. Determination of the plasma cell growth fraction with the monoclonal antibody Ki-67 in monoclonal gammopathy may help to discriminate benign monoclonal gammopathy from multiple myeloma and will probably identify a subgroup of multiple myeloma patients with a poor prognosis, including those with relapsing multiple myeloma. 相似文献