全文获取类型
收费全文 | 1399篇 |
免费 | 91篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 70篇 |
妇产科学 | 10篇 |
基础医学 | 187篇 |
口腔科学 | 21篇 |
临床医学 | 173篇 |
内科学 | 271篇 |
皮肤病学 | 52篇 |
神经病学 | 19篇 |
特种医学 | 299篇 |
外科学 | 180篇 |
综合类 | 24篇 |
预防医学 | 39篇 |
眼科学 | 5篇 |
药学 | 58篇 |
中国医学 | 2篇 |
肿瘤学 | 135篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 15篇 |
2020年 | 13篇 |
2019年 | 16篇 |
2018年 | 27篇 |
2017年 | 17篇 |
2016年 | 11篇 |
2015年 | 20篇 |
2014年 | 27篇 |
2013年 | 55篇 |
2012年 | 42篇 |
2011年 | 25篇 |
2010年 | 39篇 |
2009年 | 67篇 |
2008年 | 33篇 |
2007年 | 71篇 |
2006年 | 36篇 |
2005年 | 37篇 |
2004年 | 21篇 |
2003年 | 32篇 |
2002年 | 29篇 |
2001年 | 24篇 |
2000年 | 26篇 |
1999年 | 33篇 |
1998年 | 72篇 |
1997年 | 81篇 |
1996年 | 105篇 |
1995年 | 63篇 |
1994年 | 60篇 |
1993年 | 52篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 23篇 |
1989年 | 37篇 |
1988年 | 36篇 |
1987年 | 35篇 |
1986年 | 46篇 |
1985年 | 42篇 |
1984年 | 10篇 |
1983年 | 14篇 |
1982年 | 14篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1975年 | 14篇 |
1966年 | 4篇 |
排序方式: 共有1546条查询结果,搜索用时 0 毫秒
51.
Bot BM Eckel-Passow JE LeGrand SN Hilton T Cheville JC Igel T Parker AS 《Human pathology》2012,43(6):843-849
Despite the rising incidence of clear cell renal cell carcinoma, the molecular events that support its development and progression remain unclear. Herein, we evaluate the association of endothelin 2 expression with both clear cell renal cell carcinoma development and progression-free survival. We conducted real-time polymerase chain reaction to determine endothelin 2 expression levels on 238 patients who underwent nephrectomy for localized clear cell renal cell carcinoma, 161 of whom also had adjacent normal kidney samples available for analysis. To evaluate associations with clear cell renal cell carcinoma development, linear mixed models were used to compare differential expression between tumor and a normal kidney as well as to explore interactions with clinicopathologic features. To evaluate associations with prognosis, Cox proportional hazards models were used to assess the association of progression-free survival and endothelin 2 expression in tumor tissue. Overall, endothelin 2 expression was higher in tumor samples versus patient-matched normal kidney samples, with an average fold change of 1.99 (95% confidence interval, 1.48-2.60; P < .0001). This overexpression in tumor versus normal kidney samples was more pronounced in low- compared with high-grade tumors (interaction, P = .0002), in early- compared with late-stage tumors (interaction, P = .001), and in tumors without compared with those with necrosis (interaction, P = .001). Moreover, an increasing endothelin 2 expression in tumors was associated with a longer progression-free survival (hazard ratio, 0.89; 95% confidence interval, 0.80-0.99; P = .03); however, after controlling for known clinicopathologic factors, this association was attenuated (hazard ratio, 0.99; 95% confidence interval, 0.89-1.09; P = .7). Up-regulation of endothelin 2 is a common and early event in localized clear cell renal cell carcinoma. Higher tumor expression of endothelin 2 is associated with a longer progression-free survival but not after adjustment for well-known pathologic indices. Thus, although endothelin 2 does not appear to be an independent prognostic marker, there is evidence of a putative role in clear cell renal cell carcinoma progression. If supportive mechanistic data can be produced, endothelin 2 could represent a potential target for chemopreventive or neoadjuvant therapeutics for clear cell renal cell carcinoma. 相似文献
52.
53.
Azabdaftari G Alroy J Banner BF Ucci A Bhan I Cheville JC 《Pathology, research and practice》2008,204(10):719-723
Metanephric adenoma is a benign renal neoplasm with morphologic features similar to those of malignant renal neoplasms, such as papillary renal cell carcinoma (RCC) and Wilms' tumor. Different methods have been used to distinguish between metanephric adenoma and papillary RCC and Wilms' tumor. However, some techniques are not always available, such as certain immunohistochemical stains, cytogenetics, molecular genetics, and electron microscopy. In the current study, we compared the expression of S100 protein in 15 cases of metanephric adenoma, 10 cases of Wilms' tumor, and 13 cases of papillary RCC. Our results revealed strong expression of S100 proteins in all cases of metanephric adenoma, weak expression in two cases of Wilms' tumor, and no expression in any of the cases of papillary RCC. These findings indicate that S100 could be a useful and accessible tool for the diagnosis of metanephric adenoma. 相似文献
54.
Nynke D Scherpbier-de Haan Gerald MM Vervoort Chris van Weel Jozé CC Braspenning Jan Mulder Jack FM Wetzels Wim JC de Grauw 《The British journal of general practice》2013,63(617):e798-e806
Background
Chronic kidney disease (CKD) is highly prevalent in patients with diabetes or hypertension in primary care. A shared care model could improve quality of care in these patientsAim
To assess the effect of a shared care model in managing patients with CKD who also have diabetes or hypertension.Design and setting
A cluster randomised controlled trial in nine general practices in The Netherlands.Method
Five practices were allocated to the shared care model and four practices to usual care for 1 year. Primary outcome was the achievement of blood pressure targets (130/80 mmHg) and lowering of blood pressure in patients with diabetes mellitus or hypertension and an estimated glomerular filtration rate (eGFR)<60ml/min/1.73m2.Results
Data of 90 intervention and 74 control patients could be analysed. Blood pressure in the intervention group decreased with 8.1 (95% CI = 4.8 to 11.3)/1.1 (95% CI = −1.0 to 3.2) compared to −0.2 (95% CI = −3.8 to 3.3)/−0.5 (95% CI = −2.9 to 1.8) in the control group. Use of lipid-lowering drugs, angiotensin-system inhibitors and vitamin D was higher in the intervention group than in the control group (73% versus 51%, 81% versus 64%, and 15% versus 1%, respectively, [P = 0.004, P = 0.01, and P = 0.002]).Conclusion
A shared care model between GP, nurse practitioner and nephrologist is beneficial in reducing systolic blood pressure in patients with CKD in primary care. 相似文献55.
BO Motayo PA Akinduti FA Adeyakinu PO Okerentugba JC Nwanze CC Onoh HC Innocent-Adiele IO Okonko 《African health sciences》2013,13(4):1091-1097
Background
The increased reports of ESBL dissemination from various centres in south western, Nigeria and the recent emergence of carbapenem resistant bacteria prompted the conception of this study.Objectives
To demonstrate the relationship between high molecular weight plasmids and the expression of antibiotic multi-resistance including ESBL and carbapenemase.Methods
We investigated 97 isolates of selected organisms consisting of 67 E. coli and 30 Klebseilla spp for the presence of plasmids expressing ESBL including carbapenem-hydrolysing enzymes. Beta-lactamase was determined using acidometric method, while ESBL and carbapenemase activity was determined using the double-disk diffusion test as well as the Modified Hodge test (MHT). Plasmid profiles of ESBL and carbapenemase positive isolates were determined according to standard protocols.Results
An ESBL prevalence rate of 21.6% and carbapenem- resistance rate of 9.3% was recorded. Antibiotic susceptibility profile of ESBL isolates showed 100.0% resistance against Amoxicillin, Cotrimoxazole and Erythromycin. Moderate susceptibility was recorded against the Quinolone class of antibiotics; Meropenem remained the most active antibiotic against ESBL isolates with 62.5% against E. coli and 60% against K. pneumoniae. The plasmid profiles of our study isolates ranged from 11.8kbp to 35.5kbp.Conclusion
Due to the relationship between high molecular weight plasmids and multi-drug resistance, we hereby recommend regular molecular surveillance of this form in our study setting. 相似文献56.
Ian J Majewski Lorenza Mittempergher Nadia M Davidson Astrid Bosma Stefan M Willems Hugo M Horlings Iris de Rink Liliana Greger Gerrit KJ Hooijer Dennis Peters Petra M Nederlof Ingrid Hofland Jeroen de Jong Jelle Wesseling Roelof JC Kluin Wim Brugman Ron Kerkhoven Frank Nieboer Paul Roepman Annegien Broeks Thomas R Muley Jacek Jassem Jacek Niklinski Nico van Zandwijk Alvis Brazma Alicia Oshlack Michel van den Heuvel René Bernards 《The Journal of pathology》2013,230(3):270-276
57.
JD Roberts JC Herkert J Rutberg SM Nikkel ACP Wiesfeld D Dooijes RM Gow JP van Tintelen MH Gollob 《Clinical genetics》2013,83(5):452-456
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis. 相似文献
58.
Vignesh T. Packiam Craig V. Labbate Stephen A. Boorjian Robert Tarrell John C. Cheville Svetlana Avulova Vidit Sharma Matvey Tsivian Brittany Adamic Mohammad Mahmoud Ryan P. Werntz Norm D. Smith R. Jeffrey Karnes Matthew K. Tollefson Gary D. Steinberg Igor Frank 《Urologic oncology》2021,39(7):436.e1-436.e8
IntroductionWhile numerous current clinical trials are testing novel salvage therapies (ST) for patients with recurrent nonmuscle invasive bladder cancer (NMIBC) after bacillus Calmette-Guérin (BCG), the natural history of this disease state has been poorly defined to date. Herein, we evaluated oncologic outcomes in patients previously treated with BCG and ST who subsequently underwent radical cystectomy (RC).MethodsWe identified 378 patients with high-grade NMIBC who received at least one complete induction course of BCG (n = 378) with (n = 62) or without (n = 316) additional ST and who then underwent RC between 2000 and 2018. Oncologic outcomes were compared using the Kaplan-Meier method and Cox proportional hazards models. Sensitivity analyses were conducted stratifying by presenting tumor stage, matched 1:3 for receipt vs. no receipt of ST.ResultsPatients receiving ST were more likely to initially present with CIS (26% vs. 17%) and less likely with T1 disease (34% vs. 50%, P = 0.06) compared to patients not treated with ST. Receipt of ST was not associated with increased risk of adverse pathology (≥pT2 or pN+) at RC (31% vs. 41%, P = 0.14). Likewise, 5-year cancer-specific survival did not significantly differ between groups on univariable Kaplan-Meier analysis (73% for ST and 74% for no ST, P = 0.7). Moreover, on multivariable analysis, receipt of ST was not significantly associated the risk of death from bladder cancer (HR 1.12; 95% CI 0.60–2.09, P = 0.7). Results were unchanged on sensitivity analysis.ConclusionsThese data suggest that, in carefully selected patients, ST following BCG for high grade NMIBC does not compromise oncologic outcomes for patients who ultimately undergo RC. 相似文献
59.
Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting 总被引:2,自引:0,他引:2
Palmaz JC; Kopp DT; Hayashi H; Schatz RA; Hunter G; Tio FO; Garcia O; Alvarado R; Rees C; Thomas SC 《Radiology》1987,164(3):705-708
Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel. 相似文献
60.
Enhancement of chemotactic factor-stimulated neutrophil oxidative metabolism by leukotriene B4 总被引:4,自引:0,他引:4
Leukotriene B4 (LTB4) is a potent primary stimulator of neutrophil chemotaxis, aggregation, and degranulation and induces superoxide production at higher concentrations. In order to determine whether LTB4 modulates neutrophil responses to oxidative stimuli, human neutrophils (PMNs) were incubated with LTB4 prior to stimulation with f-Met-Leu-Phe (fMLP, 10(-7) mol/L), opsonized zymosan (OZ, 250 micrograms/mL), or phorbol myristate acetate (PMA, 32 nmol/L). Superoxide (O2-) production by stimulated PMNs was assessed by the superoxide dismutase-inhibitable reduction of cytochrome c. LTB4 alone did not stimulate O2- production in concentrations below 10(-7) mol/L and had no effect on the O2- assay. In the concentration range of 10(-12) to 10(-8) mol/L, LTB4 did not alter O2- release induced by OZ or PMA. In contrast, LTB4-treated cells demonstrated enhanced O2- production following exposure to fMLP, and in the presence of 10 nmol/LLTB4, generated 180% +/- 41% of O-2 quantities produced by control cells (n = 23). Enhancement was LTB4 dose-dependent, was maximal in the range of 1 to 10 nmol/L LTB4, was not reversed by removal of the lipid from the medium prior to fMLP stimulation, and was not dependent on the presence of Ca++ or Mg++ in the suspending medium. Chemiluminescence of fMLP-stimulated neutrophils was increased to 323% of controls in neutrophils preincubated with 10 nmol/L LTB4. Unlike augmentation of oxidative responses to fMLP seen with other degranulating stimuli, enhancement by LTB4 was not correlated with an increase in 3H-fMLP receptor binding. These results indicate that, in addition to its primary effects on neutrophil function, LTB4 modulates PMN oxidative responses to the chemotactic peptide and, thus, may amplify the release of oxygen metabolites at inflammatory foci. 相似文献