全文获取类型
收费全文 | 3551篇 |
免费 | 193篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 41篇 |
妇产科学 | 89篇 |
基础医学 | 596篇 |
口腔科学 | 122篇 |
临床医学 | 271篇 |
内科学 | 778篇 |
皮肤病学 | 49篇 |
神经病学 | 231篇 |
特种医学 | 123篇 |
外科学 | 490篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 208篇 |
眼科学 | 52篇 |
药学 | 293篇 |
中国医学 | 15篇 |
肿瘤学 | 351篇 |
出版年
2023年 | 14篇 |
2022年 | 39篇 |
2021年 | 69篇 |
2020年 | 47篇 |
2019年 | 63篇 |
2018年 | 95篇 |
2017年 | 55篇 |
2016年 | 70篇 |
2015年 | 79篇 |
2014年 | 102篇 |
2013年 | 143篇 |
2012年 | 199篇 |
2011年 | 176篇 |
2010年 | 135篇 |
2009年 | 93篇 |
2008年 | 180篇 |
2007年 | 194篇 |
2006年 | 218篇 |
2005年 | 155篇 |
2004年 | 163篇 |
2003年 | 146篇 |
2002年 | 138篇 |
2001年 | 100篇 |
2000年 | 124篇 |
1999年 | 106篇 |
1998年 | 39篇 |
1997年 | 42篇 |
1996年 | 27篇 |
1995年 | 18篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 65篇 |
1991年 | 59篇 |
1990年 | 63篇 |
1989年 | 70篇 |
1988年 | 62篇 |
1987年 | 61篇 |
1986年 | 41篇 |
1985年 | 45篇 |
1984年 | 24篇 |
1983年 | 16篇 |
1982年 | 14篇 |
1980年 | 13篇 |
1979年 | 21篇 |
1978年 | 12篇 |
1977年 | 20篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 21篇 |
1967年 | 10篇 |
排序方式: 共有3758条查询结果,搜索用时 15 毫秒
61.
P Pauletto A Angelini G Vescovo G Scannapieco C Dario G Thiene A C Pessina C Dal Palù 《International journal of cardiology》1985,8(4):361-377
Both the reproducibility of the surface measurements of aortic atherosclerosis and the agreement between gross inspective and histologic changes were evaluated. Aortas from male broad breasted white turkeys were chosen because of the high incidence of spontaneous and typical atherosclerotic lesions in this animal strain. Ten male turkeys were killed at 33 weeks of age. The aortas were removed including the iliac bifurcation and stained with Sudan III. Each aorta was processed blindly by four pathologists and a computerized planimeter to determine normal areas, sudanophilic areas and areas covered by plaques. The analysis of variance showed significant differences among the four pathologists' measurements of sudanophilic areas (P less than 0.01) and areas covered by plaques (P less than 0.001). The coefficients of variation among the four determinations made by one pathologist on the same aorta were 3.6% for total aortic area; 10.08% for sudanophilic area; 47.6% for the area covered by plaques. On each aorta histology was performed at the level where all the four pathologists recorded the same findings at inspection, namely a normal area, a sudanophilic area, and an area covered by plaques. Important discrepancies occurred between findings at inspection and those of histologic examination: the ten areas classified as "normal" by all the four pathologists at inspection were shown at histologic examination to be normal in only two cases. In one case a musculo-elastic layer and in seven cases a fibro-elastic layer were found. The ten areas classified as "sudanophilic" by all the observers showed a fibro-elastic layer in five cases, a musculo-elastic layer in two cases and normal findings in three cases. The ten areas classified as "covered by plaques" displayed a typical atherosclerotic plaque in all cases but one. In conclusion, our data indicate that the reproducibility of gross inspective methods is low. Important discrepancies exist between findings at inspection and histologic examinations. The relevance of these findings remains to be established as far as the assessment of human atherosclerosis is concerned. 相似文献
62.
Neil K. Jairath Alan Dal Pra Randy Vince Robert T. Dess William C. Jackson Jeffrey J. Tosoian Sean M. McBride Shuang G. Zhao Alejandro Berlin Brandon A. Mahal Amar U. Kishan Robert B. Den Stephen J. Freedland Simpa S. Salami Samuel D. Kaffenberger Alan Pollack Phuoc Tran Rohit Mehra Daniel E. Spratt 《European urology》2021,79(3):374-383
ContextMolecular biomarkers aim to address the established limitations of clinicopathologic factors to accurately risk stratify patients with prostate cancer (PCa). Questions remain as to whether sufficient evidence supports adoption of these biomarkers for clinical use.ObjectiveTo perform a systematic review of the available evidence supporting the clinical utility of the Decipher genomic classifier (GC).Evidence acquisitionThe review was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines by searching PubMed and conference abstracts from January 2010 to June 2020. Evidence was then graded using the criteria of Simon et al (Simon RM, Paik S, Hayes DF. Use of archived specimens in evaluation of prognostic and predictive biomarkers. J Natl Cancer Inst 2009;101:1446–52) and American Urology Association (AUA) criteria.Evidence synthesisIn total, 42 studies and 30 407 patients were included. GC performance data were available for localized, postprostatectomy, nonmetastatic castration-resistant, and metastatic hormone-sensitive PCa as part of retrospective studies (n = 12 141), prospective registries (n = 17 053), and prospective and post hoc randomized trial analyses (n = 1213). In 32 studies (n = 12 600), the GC was independently prognostic for all study endpoints (adverse pathology, biochemical failure, metastasis, and cancer-specific and overall survival) on multivariable analysis and improved the discrimination over standard of care in 24 studies (n = 8543). GC use changed the management in active surveillance (number needed to test [NNT] = 9) and postprostatectomy (NNT = 1.5–4) settings in five studies (n = 4331). Evidence strength was levels 1 and 2 by the Simon criteria for all disease states other than high-risk PCa, and grades A and B by AUA criteria depending on disease state.ConclusionsConsistent data are now present from diverse levels of evidence, which when viewed together, have demonstrated clinical utility of the GC in PCa. The utility of the GC is strongest for intermediate-risk PCa and postprostatectomy decision-making.Patient summaryIn this paper, we review the evidence of the Decipher genomic classification tool for men with prostate cancer. We found consistent evidence that the test helps identify which cancers are more or less aggressive, which in turn aids in personalized treatment decision-making. 相似文献
63.
Fausto Biancari Giovanni Mariscalco Magnus Dalén Nicla Settembre Henryk Welp Andrea Perrotti Karsten Wiebe Enrico Leo Antonio Loforte Sidney Chocron Davide Pacini Tatu Juvonen L. Mikael Broman Dario Di Perna Hakeem Yusuff Chris Harvey Nicolas Mongardon Juan P. Maureira Antonio Fiore 《Journal of cardiothoracic and vascular anesthesia》2021,35(7):1999-2006
64.
Effects of ACE inhibition in normotensive patients with chronic glomerular disease and normal renal function 总被引:1,自引:0,他引:1
V Bedogna E Valvo P Casagrande P Braggio C Fontanarosa F Dal Santo D Alberti G Maschio 《Kidney international》1990,38(1):101-107
A double-blind, placebo-controlled study was carried out to assess the effects of a three-month treatment with a new ACE inhibitor, Benazepril (BNZ), on systemic and renal hemodynamics, and urine protein excretion, in 20 patients with chronic glomerulonephritis, normal blood pressure (130/83 +/- 16/10 mm Hg), and normal renal function (creatine clearance 106 +/- 25 ml/min). Treatments with placebo or BNZ were assigned randomly. A wide range of proteinuria lowering effect was observed in overall population (from 1 to 84%, average 34%). Following the arbitrary level of a 30% reduction, two well-matched subgroups (10 patients for each one) were obtained: "good responders" (average decrease 51%), and "poor responders" (average decrease 17%). The main distinctive feature between the two groups was a higher plasma renin activity level in good than in poor responders. A positive correlation between the fall in proteinuria and blood pressure was found. Although the decrease in blood pressure seems to represent the major factor in determining the reduction in proteinuria, a multiple correlation analysis showed that the most prominent role (71%) was attributable to the combined decrease in blood pressure and filtration fraction, and then also to the efferent arteriole dilatation. Our conclusion is that ACE inhibitors are capable of also reducing proteinuria in patients with renal disease with normal blood pressure, the effect being more pronounced in those exhibiting humoral, systemic and renal hemodynamic patterns, indicating a greater activity of circulating and renal renin angiotensin system. 相似文献
65.
P Pauletto G Vescovo G Scannapieco A C Pessina C Dal Palù 《Drugs under experimental and clinical research》1990,16(3):123-128
This paper deals with some changes at the cardiac and aortic levels observed in normotensive rats and in hypertensive rats and turkeys by using two different beta-blockers, namely propranolol and oxprenolol. Chronic treatment with propranolol induced in the heart of normotensive rats a shift in the ventricular myosin pattern toward the "slow" V2 and V3 isoforms which are characterized by a reduced oxygen consumption. Oxprenolol treatment did not modify the blood pressure levels in the renal hypertensive rats nor in the spontaneously hypertensive turkeys. Nevertheless, in both experimental models a substantial modification of the media and intima, respectively, took place. In untreated hypertensive and normal rats the thickness of the aortic media was significantly higher than that of the treated ones, therefore suggesting a direct effect of oxprenolol on the smooth muscle cells of the aortic media. In the spontaneously hypertensive turkeys the atherosclerotic plaques appeared to be more frequent and thicker than those found in the oxprenolol-treated animals. These two experiments demonstrate that beta-blockers can prevent the development of hypertrophy of the media and decrease both the incidence and severity of intimal proliferations independently of blood pressure control. It therefore appears that the well-known myocardial protective effect played by beta-blockers, which mainly consists of a reduced myocardial oxygen consumption, is certainly obtained by reducing blood pressure and heart rate but also by changing the contractile protein pattern. In addition, an indirect myocardial protective effect could be exerted by beta-blockers at the vascular level by preventing medial hypertrophy and the development of atherosclerosis. 相似文献
66.
Purpose. To find out if the physical instability of a lyophilized dosage form is related to molecular mobility below the glass transition temperature. Further, to explore if the stability data generated at temperatures below the glass transition temperature can be used to predict the stability of a lyophilized solid under recommended storage conditions.
Methods. The temperature dependence of relaxation time constant, , was obtained for sucrose and trehalose formulations of the monoclonal antibody (5 mg protein/vial) from enthalpy relaxation studies using differential scanning calorimetry. The non-exponentiality parameter, , in the relaxation behavior was also obtained using dielectric relaxation spectroscopy.
Results. For both sucrose and trehalose formulations, the variation in with temperature could be fitted Vogel-Tammann-Fulcher (VTF) equation. The two formulations exhibited difference sensitivities to temperature. Sucrose formulation was more fragile and exhibited a stronger non-Arrhenius behavior compared to trehalose formulation below glass transition. Both formulations exhibited <2% aggregation at t values <10, where t is the time of storage.
Conclusions. Since the relaxation times for sucrose and trehalose formulations at 5°C are on the order of 108 and 106 hrs, it is likely that both formulations would undergo very little (<2%) aggregation in a practical time scale under refrigerated conditions. 相似文献
67.
Mast cells express a peripheral cannabinoid receptor with differential sensitivity to anandamide and palmitoylethanolamide. 总被引:21,自引:1,他引:20 下载免费PDF全文
L Facci R Dal Toso S Romanello A Buriani S D Skaper A Leon 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(8):3376-3380
Mast cells are multifunctional bone marrow-derived cells found in mucosal and connective tissues and in the nervous system, where they play important roles in tissue inflammation and in neuroimmune interactions. Very little is known about endogenous molecules and mechanisms capable of modulating mast cell activation. Palmitoylethanolamide, found in peripheral tissues, has been proposed to behave as a local autacoid capable of downregulating mast cell activation and inflammation. A cognate N-acylamide, anandamide, the ethanolamide of arachidonic acid, occurs in brain and is a candidate endogenous agonist for the central cannabinoid receptor (CB1). As a second cannabinoid receptor (CB2) has been found in peripheral tissues, the possible presence of CB2 receptors on mast cells and their interaction with N-acylamides was investigated. Here we report that mast cells express both the gene and a functional CB2 receptor protein with negative regulatory effects on mast cell activation. Although both palmitoylethanolamide and anandamide bind to the CB2 receptor, only the former downmodulates mast cell activation in vitro. Further, the functional effect of palmitoylethanolamide, as well as that of the active cannabinoids, was efficiently antagonized by anandamide. The results suggest that (i) peripheral cannabinoid CB2 receptors control, upon agonist binding, mast cell activation and therefore inflammation; (ii) palmitoylethanolamide, unlike anandamide, behaves as an endogenous agonist for the CB2 receptor on mast cells; (iii) modulatory activities on mast cells exerted by the naturally occurring molecule strengthen a proposed autacoid local inflammation antagonism (ALIA) mechanism; and (iv) palmitoylethanolamide and its derivatives may provide antiinflammatory therapeutic strategies specifically targeted to mast cells ("ALIAmides"). 相似文献
68.
Reliability of self-reported behavioural health risk factors in a South Australian telephone survey 总被引:2,自引:0,他引:2
Starr GJ Dal Grande E Taylor AW Wilson DH 《Australian and New Zealand journal of public health》1999,23(5):528-530
OBJECTIVE: To test the reliability of telephone health survey questions. METHOD: A telephone survey on mental health of South Australians in 1997 was re-administered to a random sub-sample of 102 respondents between 32 and 79 days after the original survey. RESULTS: Demographic questions (age, gender, number of adults and children in the household) showed the highest reproducibility and were almost perfect. Questions regarding health risk factors, such as smoking and drinking behaviour, showed substantial to almost perfect agreement. Co-morbidity variables were substantially reproducible where prevalence estimates were not close to zero. CONCLUSIONS: The results were comparable to findings from similar studies associated with the Behavioral Risk Factor Surveillance System (BRFSS) in the United States. The study suggests that the telephone health survey instrument used in South Australia is reliable for estimating health conditions and behaviours in the population. 相似文献
69.
Wilson DH Starr GJ Taylor AW Dal Grande E 《Australian and New Zealand journal of public health》1999,23(6):627-633
OBJECTIVE: To compare the methodologies of and health estimates derived from two telephone household survey methods. In particular, to establish if White Pages telephone listings provide a relatively unbiased sampling frame for population health surveys. METHOD: In South Australia in 1998, a health survey questionnaire was administered by telephone to two randomly selected population samples. The first method used EWP (Electronic White Pages, n = 6,012), which contains all listed residential telephone numbers as the sampling frame. The results were compared to a RDD (random digit dialling, n = 3,080) sample where all listed and unlisted telephone numbers were included in the sampling frame. Demographic variables and health estimates were compared between the surveys, and then compared to a 'gold standard' door-to-door household survey conducted concurrently. RESULTS: The response rate for EWP (83.8%) exceeded that of RDD (65.4%). More than four times as many calls were required per completed interview in RDD. Demographic profiles and health estimates were substantially similar. CONCLUSIONS: EWP requires fewer telephone calls and enables approach letters establishing the bona fides of the survey to be sent to each selected address before calling, increasing the response rate. RDD is a more inclusive sampling frame but also includes non-connected and business numbers, and offers no significant advantages in providing health estimates. IMPLICATIONS: There are substantial methodological and cost advantages in using EWP over RDD as the sampling, frame for population health surveys, without introducing significant bias into health estimates. 相似文献
70.
Dominioni L Dionigi R Jemos V Bonomi E Melzi d'Eril GV Dal Ri P 《Clinical nutrition (Edinburgh, Scotland)》1983,1(4):297-303
The serum level of six acute phase proteins (APP) has been evaluated preoperatively and for a few days in the postoperative period. Thirty patients undergoing total gastrectomy for gastric cancer have been studied in two subgroups according to their nutritional status. Those with gastric cancer had significantly higher baseline serum levels of alpha 1 acid glycoprotein (alpha1AGP) and C-reactive protein (CRP) than a control group. Malnourished patients also had reduced acute phase response for alpha1AGP and alpha 1 antitrypsin (alpha1AT) a higher increase of CRP and fibrinogen, and a lower decrease for transferrin and retinol binding protein (RBP). 相似文献