全文获取类型
收费全文 | 2350篇 |
免费 | 141篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 96篇 |
妇产科学 | 38篇 |
基础医学 | 421篇 |
口腔科学 | 26篇 |
临床医学 | 296篇 |
内科学 | 458篇 |
皮肤病学 | 49篇 |
神经病学 | 231篇 |
特种医学 | 51篇 |
外科学 | 219篇 |
综合类 | 12篇 |
预防医学 | 208篇 |
眼科学 | 28篇 |
药学 | 189篇 |
中国医学 | 3篇 |
肿瘤学 | 158篇 |
出版年
2023年 | 17篇 |
2022年 | 19篇 |
2021年 | 45篇 |
2020年 | 32篇 |
2019年 | 46篇 |
2018年 | 69篇 |
2017年 | 47篇 |
2016年 | 57篇 |
2015年 | 58篇 |
2014年 | 90篇 |
2013年 | 120篇 |
2012年 | 189篇 |
2011年 | 204篇 |
2010年 | 109篇 |
2009年 | 95篇 |
2008年 | 163篇 |
2007年 | 157篇 |
2006年 | 150篇 |
2005年 | 134篇 |
2004年 | 111篇 |
2003年 | 118篇 |
2002年 | 95篇 |
2001年 | 24篇 |
2000年 | 20篇 |
1999年 | 26篇 |
1998年 | 30篇 |
1997年 | 20篇 |
1996年 | 27篇 |
1995年 | 15篇 |
1994年 | 13篇 |
1993年 | 11篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 19篇 |
1988年 | 10篇 |
1987年 | 14篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1982年 | 5篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1967年 | 5篇 |
排序方式: 共有2508条查询结果,搜索用时 15 毫秒
41.
Stacher G Lenglinger J Bergmann H Schneider C Brannath W Festa A Meghdadi S Stacher-Janotta G 《Digestive diseases and sciences》2003,48(6):1027-1034
Previous studies in diabetic patients suggested a relationship between delayed gastric emptying and increased ingesta retention in either proximal or distal stomach, but the determinants underlying these abnormalities remained obscure. We aimed at assessing the impact of cardiovascular autonomic neuropathy, blood glucose concentration, long-term glycemic control, and other factors in 34 type I and 43 type II diabetic patients (ages 21–67 and 34–81 years, respectively). Emptying was slower (P < 0.04) in type I diabetic patients than in 20 healthy control subjects (ages 23–63 years). Patients with autonomic neuropathy (N = 45) had slower gastric emptying (P < 0.02) and retained more in the distal stomach (P < 0.0001) than patients without neuropathy (N = 32). Multiple regression analyses revealed that slow emptying and increased distal retention were significantly associated with autonomic neuropathy (P < 0.043, P < 0.0002), whereas blood glucose, glycemic control, diabetes duration, age, and other factors had no discernible influence. Thus, both slow emptying and increased distal ingesta retention seem primarily referable to autonomic neuropathy. 相似文献
42.
Arnoud A. Bruins Kay R. J. Kistemaker Annemieke Boom John H. G. M. Klaessens Rudolf M. Verdaasdonk Christa Boer 《Journal of clinical monitoring and computing》2018,32(2):335-341
Due to the high rates of epidural failure (3–32%), novel techniques are required to objectively assess the successfulness of an epidural block. In this study we therefore investigated whether thermographic temperature measurements have a higher predictive value for a successful epidural block when compared to the cold sensation test as gold standard. Epidural anesthesia was induced in 61 patients undergoing elective abdominal, thoracic or orthopedic surgery. A thermographic picture was recorded at 5, 10 and 15 min following epidural anesthesia induction. After 15 min a cold sensation test was performed. Epidural anesthesia is associated with a decrease in skin temperature. Thermography predicts a successful epidural block with a sensitivity of 54% and a PPV of 92% and a specificity of 67% and a NPV of 17%. The cold sensation test shows a higher sensitivity and PPV than thermography (97 and 93%), but a lower specificity and NPV than thermography (25 and 50%). Thermographic temperature measurements can be used as an additional and objective method for the assessment of the effectiveness of an epidural block next to the cold sensation test, but have a low sensitivity and negative predictive value. The local decrease in temperature as observed in our study during epidural anesthesia is mainly attributed to a core-to-peripheral redistribution of body heat and vasodilation. 相似文献
43.
44.
What do people appreciate in physicians' communication? An international study with focus groups using videotaped medical consultations 下载免费PDF全文
Maria A. Mazzi MSc Michela Rimondini PhD Myriam Deveugele PhD Christa Zimmermann PhD Francesca Moretti PhD Liesbeth van Vliet PhD Giuseppe Deledda MSc Ian Fletcher PhD Jozien Bensing PhD 《Health expectations》2015,18(5):1215-1226
Background
The literature shows that the quality of communication is usually determined from a professional perspective. Patients or lay people are seldom involved in the development of quality indicators or communication.Objective
To give voice to the lay people perspective on what constitutes ‘good communication’ by evoking their reactions to variations in physician communication.Design
Lay people from four different countries watched the same videotaped standardized medical encounters and discussed their preferences in gender‐specific focus groups who were balanced in age groups.Setting and participants
Two hundred and fifty‐nine lay people (64 NL, 72 IT, 75 UK and 48 BE) distributed over 35 focus groups of 6–8 persons each.Main variables studied
Comments on doctors'' behaviours were classified by the GULiVer framework in terms of contents and preferences.Results
Participants prevalently discussed ‘task‐oriented expressions’ (39%: competency, self‐confident, providing solutions), ‘affective oriented/emotional expressions'' (25%: empathy, listening, reassuring) and ‘process‐oriented expressions'' (23%: flexibility, summarizing, verifying). ‘Showing an affective attitude’ was most appreciated (positive percentage within category: 93%, particularly facilitations and inviting attitude), followed by ‘providing solution’ (85%). Among disfavoured behaviour, repetitions (88%), ‘writing and reading’ (54%) and asking permission (42%) were found.Conclusions
Although an affective attitude is appreciated by nearly everybody, people may vary widely in their communication needs and preferences: what is ‘good communication’ for one person may be disliked or even a source of irritation for another. A physician should be flexible and capable of adapting the consultation to the different needs of different patients. This challenges the idea of general communication guidelines. 相似文献45.
Jazbutyte V Arias-Loza PA Hu K Widder J Govindaraj V von Poser-Klein C Bauersachs J Fritzemeier KH Hegele-Hartung C Neyses L Ertl G Pelzer T 《Cardiovascular research》2008,77(4):774-781
AIMS: The biological effects of oestrogens are mediated by two different oestrogen receptor (ER) subtypes, ERalpha and ERbeta, which might play different, redundant, or opposing roles in cardiovascular disease. Previously, we have shown that the selective ERalpha agonist 16alpha-LE2 improves vascular relaxation, attenuates cardiac hypertrophy, and increases cardiac output without lowering elevated blood pressure in spontaneously hypertensive rats (SHR). Because ERbeta-deficient mice exhibit elevated blood pressure and since the ERbeta agonist 8beta-VE2 attenuated hypertension in aldosterone-salt-treated rats, we have now tested the hypothesis that the isotype-selective ERbeta agonist 8beta-VE2 might be capable of lowering elevated blood pressure in ovariectomized SHR. METHODS AND RESULTS: Treatment of ovariectomized SHR with 8beta-VE2 for 12 weeks conferred no uterotrophic effects but lowered elevated systolic blood pressure (-38 +/- 5 mmHg, n = 31, P < 0.001 vs. placebo) as well as peripheral vascular resistance (-31.3 +/- 4.6%, P < 0.001 vs. placebo). 8beta-VE2 enhanced aortic ERbeta expression (+75.7 +/- 7.1%, P < 0.01 vs. placebo), improved NO-dependent vasorelaxation, augmented phosphorylation of the vasodilator-stimulated phosphoprotein in isolated aortic rings (P < 0.05 vs. placebo), increased cardiac output (+20.4 +/- 2.5%, P < 0.01 vs. placebo), and attenuated cardiac hypertrophy (-22.2 +/- 3.2%, p < 0.01 vs. placebo). 8beta-VE2, in contrast to oestradiol, did not enhance cardiac alpha-myosin heavy chain expression. CONCLUSION: Ligand-dependent activation of ERbeta confers blood pressure lowering effects in SHR that are superior to those of 17beta-estradiol or the ERalpha agonist 16alpha-LE2 and attenuates cardiac hypertrophy primarily by a reduction of cardiac afterload without promoting uterine growth. 相似文献
46.
Sabrina Krautbauer Kristina Eisinger Madeleine Lupke Josef Wanninger Petra Ruemmele Yvonne Hader Thomas S. Weiss Christa Buechler 《Experimental and molecular pathology》2013
Non-alcoholic fatty liver disease (NAFLD) is among the most common liver diseases. Oxidative stress is one of the pathogenic mechanisms contributing to the progression of simple fatty liver to non-alcoholic steatohepatitis (NASH). Manganese superoxide dismutase (MnSOD) is a mitochondrial antioxidative enzyme and here its expression in rodent and human NAFLD has been analyzed. MnSOD is found reduced in the liver of male mice fed a high fat diet and male ob/ob mice. Female mice fed an atherogenic diet to induce NASH have MnSOD protein levels comparable to controls. In a cohort of 30 controls, 41 patients with fatty liver and 39 NASH patients, MnSOD mRNA is significantly lower in the steatotic and NASH liver. When analyzed in both genders separately reduction of MnSOD expression is only found in males. Here, MnSOD mRNA negatively correlates with steatosis grade but not with extent of fibrosis or inflammation. MnSOD is, however, not reduced in primary human hepatocytes (PHH) treated with palmitate or oleate to increase cellular triglycerides. Lipopolysaccharide, TNF, IL-6, TGFβ and leptin which are all raised in NAFLD do not affect MnSOD in PHH. Adiponectin which attenuates oxidative stress partly by increasing MnSOD in macrophages does not induce MnSOD in PHH. In summary, current data show that hepatic MnSOD is reduced in male but not female humans and rodents with NAFLD. 相似文献
47.
Francis Dziva Heidi Hauser Thomas R. Connor Pauline M. van Diemen Graham Prescott Gemma C. Langridge Sabine Eckert Roy R. Chaudhuri Christa Ewers Melha Mellata Suman Mukhopadhyay Roy Curtiss III Gordon Dougan Lothar H. Wieler Nicholas R. Thomson Derek J. Pickard Mark P. Stevens 《Infection and immunity》2013,81(3):838-849
Avian pathogenic Escherichia coli (APEC) causes respiratory and systemic disease in poultry. Sequencing of a multilocus sequence type 95 (ST95) serogroup O1 strain previously indicated that APEC resembles E. coli causing extraintestinal human diseases. We sequenced the genomes of two strains of another dominant APEC lineage (ST23 serogroup O78 strains χ7122 and IMT2125) and compared them to each other and to the reannotated APEC O1 sequence. For comparison, we also sequenced a human enterotoxigenic E. coli (ETEC) strain of the same ST23 serogroup O78 lineage. Phylogenetic analysis indicated that the APEC O78 strains were more closely related to human ST23 ETEC than to APEC O1, indicating that separation of pathotypes on the basis of their extraintestinal or diarrheagenic nature is not supported by their phylogeny. The accessory genome of APEC ST23 strains exhibited limited conservation of APEC O1 genomic islands and a distinct repertoire of virulence-associated loci. In light of this diversity, we surveyed the phenotype of 2,185 signature-tagged transposon mutants of χ7122 following intra-air sac inoculation of turkeys. This procedure identified novel APEC ST23 genes that play strain- and tissue-specific roles during infection. For example, genes mediating group 4 capsule synthesis were required for the virulence of χ7122 and were conserved in IMT2125 but absent from APEC O1. Our data reveal the genetic diversity of E. coli strains adapted to cause the same avian disease and indicate that the core genome of the ST23 lineage serves as a chassis for the evolution of E. coli strains adapted to cause avian or human disease via acquisition of distinct virulence genes. 相似文献
48.
Cloning of the cDNA encoding the large subunit of human RNase HI, a homologue of the prokaryotic RNase HII 总被引:5,自引:0,他引:5 下载免费PDF全文
49.
50.
Sorgho H Bahgat M Poda JN Song W Kirsten C Doenhoff MJ Zongo I Ouédraogo JB Ruppel A 《Acta tropica》2005,93(2):169-180
The performance of indirect haemagglutination assays (IHA), enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescent antibody tests (IFAT) were compared with 450 sera from a Schistosoma mansoni-endemic area in Burkina Faso. All participants in this survey provided at least one sample each of stool, urine and serum. From those with an egg-negative Kato-Katz thick smear, a second stool sample was examined. IHA was based on either extracts of adult S. mansoni worms (SmIHA) or S. japonicum egg antigen (SjIHA). For ELISA, three antigen preparations were used, namely: (i) soluble S. mansoni adult worm antigens (SWAP); (ii) soluble S. mansoni egg antigens (SEA); and (iii) a cationic exchange fraction of S. mansoni eggs (CEF6). IFAT was performed with S. mansoni male worm sections. Among the egg-excretors, the sensitivity of ELISA was high and egg antigens performed slightly better (SEA, 96%; CEF6, 97%) than worm antigen (94%). Sensitivity of IHA was satisfactory with homologous (Sm, >85%), but not heterologous (Sj, 56%) parasite antigen. In IFAT, the parenchyma-associated fluorescence showed high sensitivity (95%), but gut-associated fluorescence, which is known to be a sensitive diagnostic marker for schistosome-infected European travelers, was observed only in 76% of a sub-sample of 100 of the endemic sera. Among sera from egg-negative individuals, many gave positive reactions in several or all of the tests employed. These reactions (formally "false positive") are considered to represent true infections, since chemotherapy had not yet been delivered to this population. For the purpose of further surveys in Burkina Faso or other resource-poor settings, we suggest IHA as an accurate diagnostic test and propose to further improve its performance by including egg rather than worm antigens. 相似文献