全文获取类型
收费全文 | 1210篇 |
免费 | 133篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 28篇 |
妇产科学 | 16篇 |
基础医学 | 182篇 |
口腔科学 | 9篇 |
临床医学 | 137篇 |
内科学 | 220篇 |
皮肤病学 | 18篇 |
神经病学 | 130篇 |
特种医学 | 73篇 |
外科学 | 74篇 |
综合类 | 7篇 |
一般理论 | 4篇 |
预防医学 | 202篇 |
眼科学 | 42篇 |
药学 | 137篇 |
肿瘤学 | 55篇 |
出版年
2024年 | 3篇 |
2023年 | 26篇 |
2022年 | 28篇 |
2021年 | 51篇 |
2020年 | 31篇 |
2019年 | 61篇 |
2018年 | 63篇 |
2017年 | 32篇 |
2016年 | 40篇 |
2015年 | 39篇 |
2014年 | 42篇 |
2013年 | 68篇 |
2012年 | 110篇 |
2011年 | 88篇 |
2010年 | 48篇 |
2009年 | 43篇 |
2008年 | 55篇 |
2007年 | 81篇 |
2006年 | 76篇 |
2005年 | 58篇 |
2004年 | 54篇 |
2003年 | 29篇 |
2002年 | 32篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 11篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1985年 | 7篇 |
1982年 | 3篇 |
1977年 | 3篇 |
1975年 | 5篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1966年 | 4篇 |
1963年 | 5篇 |
1938年 | 2篇 |
排序方式: 共有1343条查询结果,搜索用时 15 毫秒
1.
Feasibility and Diagnostic Potential of Pulmonary Transit Time Measurement by Contrast Echocardiography: A Pilot Study
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
2.
3.
4.
5.
Kirsty E Amos Shahram Anari Charlotte A Buswell Emma J McNeill Athanasia Printza Stephen J Ray Isam Rustom 《Annals of general psychiatry》2006,5(1):1-5
Background
The aim of the current study is to investigate the relationship between physical anhedonia and psychopathological parameters, pharmacological parameters or motor side-effects in a sample of inpatients with schizophrenia in an acute episode of their illness. 相似文献6.
Paula Jablonski Kirsty Baxter Brian O. Howden Anita C. Thomas Vernon C. Marshall Alicia Stein-Oakley Napier M. Thomson 《ANZ journal of surgery》1995,65(2):114-119
A reproducible animal model is essential for the study of the pathogenesis of chronic rejection. This study investigates: (i) the optimal pre-transplant blood transfusion conditions to induce tolerance in a strongly rejecting rat kidney allograft model (Dark Agouti to Albino-Surgery) and avoiding post-transplant immunosuppression; (ii) the functional and histological changes that occur in long-term surviving kidneys and their similarity to chronic rejection; and (iii) the maintenance of tolerance. Prolonged survival occurred after administration of at least two donor blood transfusions with concomitant cyclosporin A (5 mg/kg per day). The time-span between transfusions appeared to be critical: 4 days was more effective than 2 or 7 days. Ineffective treatment led to death within the first 2 weeks post-transplant with histological evidence of acute graft rejection. Seventy-five per cent of long-term survivors experienced impaired renal function in the first week which improved spontaneously and remained stable in 93% of the surviving animals after 100 days and in 668 after 200 days. The morphology of long-term allografts was extremely variable from minor to extensive tubular atrophy, interstitial fibrosis, glomerular hypertrophy, focal and segmental glomerulosclerosis and vascular changes. Glomerular hypertrophy occurred in uninephrectomized controls and probably denoted a response to uninephrectomy. Glomerulosclerosis increased with time and was absent in controls. Although chronic damage was evident, the rats remained tolerant to fresh donor skin. Replacement of the original kidney allograft with a fresh donor kidney resulted in 70% survival. These second grafts showed less severe renal dysfunction and morphological damage than the original allografts in the long-term follow up. 相似文献
7.
Corrigan C Mallett K Ying S Roberts D Parikh A Scadding G Lee T 《The Journal of allergy and clinical immunology》2005,115(2):316-322
BACKGROUND: Cysteinyl leukotrienes play a disease-regulating role in rhinosinusitis and asthma, particularly aspirin-sensitive disease. They act through 2 G-protein coupled receptors termed cysteinyl leukotriene type 1 receptor (cysLT 1 ) and cysteinyl leukotriene type 2 receptor (cysLT 2 ). We previously compared expression of cysLT 1 on mucosal leukocytes in patients with aspirin-sensitive and aspirin-tolerant rhinosinusitis. OBJECTIVE: To compare expression of cysLT 1 and cysLT 2 on leukocytes, mucus glands, and epithelium in 32 patients with chronic polypoid rhinosinusitis (21 aspirin-sensitive, 11 aspirin-tolerant) and 9 normal controls. METHODS: Total numbers of CD45 + leukocytes, percentages of these cells expressing cysLT 1 or cysLT 2 , and percentages of the total epithelial and glandular areas expressing cysLT 1 or cysLT 2 were measured in sections of nasal biopsies by using immunohistochemistry and image analysis. RESULTS: The percentages of mucosal CD45 + leukocytes expressing cysLT 1 were significantly ( P < .0001) elevated in the aspirin-sensitive but not the aspirin-tolerant patients compared with the controls. In contrast, the percentages of leukocytes expressing cysLT 2 did not differ significantly in the 3 groups. On epithelial and glandular cells, expression of cysLT 2 significantly exceeded that of cysLT 1 in both the patients with rhinosinusitis and the controls ( P < or = .004), although there was no significant difference in the expression of either receptor in the patients with rhinosinusitis (aspirin-sensitive or aspirin-tolerant) and the controls. CONCLUSION: Although cysLT 1 expression predominates on inflammatory leukocytes in patients with aspirin-sensitive rhinosinusitis, the effects of cysteinyl leukotrienes on glands and epithelium may be mediated predominantly through cysLT 2. This has potentially important therapeutic implications. 相似文献
8.
Utility of a multiplex PCR assay for detecting herpesvirus DNA in clinical samples 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Druce J Catton M Chibo D Minerds K Tyssen D Kostecki R Maskill B Leong-Shaw W Gerrard M Birch C 《Journal of clinical microbiology》2002,40(5):1728-1732
A multiplex PCR was designed to amplify herpes simplex virus types 1 and 2, cytomegalovirus, and varicella-zoster virus DNA present in a diverse range of clinical material. The susceptibility of these viruses to in vivo inhibition by at least one antiviral drug was an important consideration in their inclusion in the multiplex detection system. An aliquot of equine herpesvirus was introduced into each specimen prior to extraction and served as an indicator of potential inhibitors of the PCR and a detector of suboptimal PCR conditions. Compared to virus isolation and immunofluorescence-based antigen detection, the multiplex assay yielded higher detection rates for all viruses represented in the assay. The turnaround time for performance of the assay was markedly reduced compared to those for the other techniques used to identify these viruses. More than 21,000 tests have been performed using the assay. Overall, the multiplex PCR enabled the detection of substantially increased numbers of herpesviruses, in some cases in specimens or anatomical sites where previously they were rarely if ever identified using traditional detection methods. 相似文献
9.
Characterization of clinical isolates of Klebsiella pneumoniae from 19 laboratories using the National Committee for Clinical Laboratory Standards extended-spectrum beta-lactamase detection methods 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Steward CD Rasheed JK Hubert SK Biddle JW Raney PM Anderson GJ Williams PP Brittain KL Oliver A McGowan JE Tenover FC 《Journal of clinical microbiology》2001,39(8):2864-2872
Extended-spectrum beta-lactamases (ESBLs) are enzymes found in gram-negative bacilli that mediate resistance to extended-spectrum cephalosporins and aztreonam. In 1999, the National Committee for Clinical Laboratory Standards (NCCLS) published methods for screening and confirming the presence of ESBLs in Klebsiella pneumoniae, Klebsiella oxytoca, and Escherichia coli. To evaluate the confirmation protocol, we tested 139 isolates of K. pneumoniae that were sent to Project ICARE (Intensive Care Antimicrobial Resistance Epidemiology) from 19 hospitals in 11 U.S. states. Each isolate met the NCCLS screening criteria for potential ESBL producers (ceftazidime [CAZ] or cefotaxime [CTX] MICs were > or =2 microg/ml for all isolates). Initially, 117 (84%) isolates demonstrated a clavulanic acid (CA) effect by disk diffusion (i.e., an increase in CAZ or CTX zone diameters of > or =5 mm in the presence of CA), and 114 (82%) demonstrated a CA effect by broth microdilution (reduction of CAZ or CTX MICs by > or =3 dilutions). For five isolates, a CA effect could not be determined initially by broth microdilution because of off-scale CAZ results. However, a CA effect was observed in two of these isolates by testing cefepime and cefepime plus CA. The cefoxitin MICs for 23 isolates that failed to show a CA effect by broth microdilution were > or =32 microg/ml, suggesting either the presence of an AmpC-type beta-lactamase or porin changes that could mask a CA effect. By isoelectric focusing (IEF), 7 of the 23 isolates contained a beta-lactamase with a pI of > or =8.3 suggestive of an AmpC-type beta-lactamase; 6 of the 7 isolates were shown by PCR to contain both ampC-type and bla(OXA) genes. The IEF profiles of the remaining 16 isolates showed a variety of beta-lactamase bands, all of which had pIs of < or =7.5. All 16 isolates were negative by PCR with multiple primer sets for ampC-type, bla(OXA), and bla(CTX-M) genes. In summary, 83.5% of the K. pneumoniae isolates that were identified initially as presumptive ESBL producers were positive for a CA effect, while 5.0% contained beta-lactamases that likely masked the CA effect. The remaining 11.5% of the isolates studied contained beta-lactamases that did not demonstrate a CA effect. An algorithm based on phenotypic analyses is suggested for evaluation of such isolates. 相似文献
10.
Elliott KJ Cable NT Reilly T Sefton V Kingsland C Diver M 《Experimental physiology》2005,90(2):215-223
The purpose of this study was to investigate the effects of supra-physiological changes in ovarian hormone levels on maximum force production in two conditions, one physiological (pregnancy) and one pseudo-physiological (in vitro fertilization (IVF) treatment). Forty IVF patients were tested at four distinct stages of treatment and 35 women were tested during each trimester of pregnancy and following parturition. Maximum voluntary isometric force per unit cross-sectional area of the first dorsal interosseus muscle was measured. Plasma concentrations of total and bioavailable oestradiol and testosterone were measured, in addition to the total concentrations of progesterone and human chorionic gonadotropin. Despite significant changes in the concentrations of total progesterone, 17beta-oestradiol, bioavailable oestradiol and testosterone between phases, strength did not change significantly throughout IVF treatment (1.30+/-0.29, 1.16+/-0.38, 1.20+/-0.29 and 1.26+/-0.34 N mm-2, respectively, in the 4 phases of IVF treatment). Force production was significantly higher during the second trimester of pregnancy than following childbirth (1.33+/-0.20 N mm-2 at week 12 of pregnancy, 1.51+/-0.42 N mm-2 at week 20, 1.15+/-0.26 N mm-2 at week 36 and 0.94+/-0.31 N mm-2 at week 6 postnatal) but was not significantly correlated with any of the hormones measured. These data suggest that extreme changes in the concentrations of reproductive hormones do not affect the maximum force-generating capacity of young women. 相似文献