全文获取类型
收费全文 | 1710篇 |
免费 | 66篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 52篇 |
妇产科学 | 38篇 |
基础医学 | 114篇 |
口腔科学 | 58篇 |
临床医学 | 386篇 |
内科学 | 517篇 |
皮肤病学 | 51篇 |
神经病学 | 45篇 |
特种医学 | 10篇 |
外科学 | 145篇 |
综合类 | 29篇 |
一般理论 | 18篇 |
预防医学 | 120篇 |
眼科学 | 19篇 |
药学 | 142篇 |
中国医学 | 3篇 |
肿瘤学 | 22篇 |
出版年
2017年 | 18篇 |
2016年 | 21篇 |
2015年 | 26篇 |
2014年 | 32篇 |
2013年 | 44篇 |
2012年 | 10篇 |
2010年 | 51篇 |
2009年 | 60篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 17篇 |
2005年 | 11篇 |
2003年 | 12篇 |
2001年 | 24篇 |
2000年 | 14篇 |
1999年 | 43篇 |
1998年 | 60篇 |
1997年 | 91篇 |
1996年 | 94篇 |
1995年 | 59篇 |
1994年 | 58篇 |
1993年 | 64篇 |
1992年 | 51篇 |
1991年 | 55篇 |
1990年 | 49篇 |
1989年 | 56篇 |
1988年 | 53篇 |
1987年 | 40篇 |
1986年 | 32篇 |
1985年 | 28篇 |
1984年 | 41篇 |
1983年 | 38篇 |
1982年 | 26篇 |
1981年 | 33篇 |
1980年 | 23篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1971年 | 20篇 |
1968年 | 11篇 |
1959年 | 19篇 |
1958年 | 30篇 |
1957年 | 26篇 |
1956年 | 38篇 |
1955年 | 30篇 |
1954年 | 26篇 |
1949年 | 10篇 |
1948年 | 12篇 |
排序方式: 共有1779条查询结果,搜索用时 9 毫秒
51.
52.
Michael L. ALOSCO Andreana BENITEZ John GUNSTAD Mary Beth SPITZNAGEL Jeanne M. MCCAFFERY John E. MCGEARY Athena POPPAS Robert H. PAUL Lawrence H. SWEET Ronald A. COHEN 《Psychogeriatrics》2013,13(1):35-40
Background: Much attention has been paid to the prevalence and predisposition of the fat mass and obesity‐associated (FTO) gene to obesity, although only a few studies have characterized the extent to which this affects cognitive function. This study examined differences between risk allele carriers (i.e. FTO‐AC/AA) and non‐carriers (i.e. FTO‐CC) on indices of attention/executive function/psychomotor speed, memory, language, and visual‐spatial ability in a sample of older patients with cardiovascular disease. Methods: We recruited 120 older adults from an outpatient cardiology clinic who underwent blood draw and completed neuropsychological testing. Participants were classified into two groups: one for those who were homozygous for the non‐risk‐conferring allele (i.e. FTO‐CC) (n= 49) and the other for those who had at least one copy of the obesity risk‐conferring A allele (i.e. FTO‐AC/AA) (n= 71). Results: Mancova analyses adjusting for age and years of education revealed the FTO‐AC/AA group performed significantly worse on indices of memory (λ= 0.94, F(2, 115) = 3.58, P= 0.03, partial η2= 0.06). Follow‐up tests revealed a significant effect for the FTO‐AC/AA group, relative to the non‐carrier group, on encoding (i.e. California Verbal Learning Test Total Learning) and California Verbal Learning Test long‐delay free recall (P < 0.05). No such differences between FTO carriers and non‐carriers emerged on tests of attention/executive function/psychomotor speed, language, or visual‐spatial ability (P > 0.05 for all). Conclusions: These findings suggest that the FTO risk allele is associated with reduced memory performance, particularly on aspects of memory encoding and delayed recall. To elucidate underlying mechanisms, these findings will need to be replicated in larger samples that utilize neuroimaging. 相似文献
53.
54.
Variation in the Amount of Hemoglobin S in a Patient with Sickle Cell Trait and Megaloblastic Anemia 总被引:4,自引:0,他引:4
A patient with sickle cell trait and nutritional megaloblastic anemia wasfound to have a much smaller proportion of hemoglobin S during the megaloblastic phase than after recovery. This observation suggests preferential synthesis of hemoglobin A by megaloblastic bone marrow in the presence of theA-S trait. Submitted on July 30, 1962 Accepted on November 9, 1962 相似文献
55.
LUKAS BUBENDORF GUIDO SAUTER HOLGER MOCH HANS-PETER SCHMID THOMAS C. GASSER PAUL JORDAN MICHAEL J. MIHATSCH 《The Journal of pathology》1996,178(4):437-441
The clinical course of prostate cancer is highly variable and cannot satisfactorily be predicted by histological criteria alone. Both tumour cell proliferation and neuroendocrine differentiation have been suggested as additional prognostic parameters, neuroendocrine differentiation being considered to enhance tumour cell proliferation. This study investigated the prognostic value of tumour cell proliferation [Ki67 labelling index (LI), MIB 1] and neuroendocrine differentiation and their relationship to each other. One hundred and thirty-seven paraffin-embedded radical prostatectomy specimens were examined. Neuroendocrine differentiation was found in 58 per cent of cases, but was not associated with pTN stage, Gleason score, Ki67 LI, or tumour progression. Ki67 LI was not significantly associated with pTN stage or with Gleason score. High grade ( P =0·0005), advanced local stage ( P =0·0004), positive lymph nodes ( P =0·02), and high Ki67 LI ( P =0·0203) were predictors of tumour progression if univariate analysis was performed, but Cox stepwise regression showed that only advanced local stage ( P =0·0025) and Ki67 LI ( P =0·0105) were independent predictors of tumour progression, the relative risk being 3·6 and 2·5, respectively. It is concluded that Ki67 is an important prognostic marker in prostate cancer with a potential for routine application. 相似文献
56.
RICHARD J. CALVERT PAUL A. S. EVANS JULIETTE A. RANDERSON ANDREW S. JACK GARETH J. MORGAN MICHAEL F. DIXON 《The Journal of pathology》1996,180(1):26-32
The significance of the demonstration of a clonal B-cell population in gastric lymphoid infiltrates was investigated by analysis of immunoglobulin heavy chain (IgH) gene rearrangements using sensitive polymerase chain reactions, employing fluorescently labelled primers to target the FR3 and FR1 regions. Tissue blocks were studied showing different histological features (high-grade lymphoma, low-grade lymphoma, and chronic gastritis) from 12 gastrectomies for primary gastric lymphoma, together with blocks showing chronic gastritis from 13 cases of gastric adenocarcinoma and biopsies from 33 patients with active Helicobacter -associated chronic gastritis. Clonal IgH gene rearrangements were detected in lymphoma samples from eight of the gastrectomies for lymphoma (67 per cent). In four of these eight specimens, clonal rearrangements were also detectable in the samples showing only chronic gastritis. Three of 28 (11 per cent) informative biopsies showing active Helicobacter -associated chronic gastritis had detectable clonal populations. Clonal rearrangements were also demonstrated in two of eight (25 per cent) informative blocks showing chronic gastritis from eight gastrectomies for adenocarcinoma. It is concluded that the detection of a clonal population in a suspicious lymphoid infiltrate does not confirm the diagnosis of lymphoma, nor does the absence of such a population imply benignity. 相似文献
57.
IAN APPLETON NICOLA J. BROWN DEAN WILLIS PAUL R. COLVILLE-NASH CHANDON ALAM JOANNE R. BROWN DEREK A. WILLOUGHBY 《The Journal of pathology》1996,180(1):90-94
Chronic granulomatous inflammation may be considered an angiogenic-dependent process. Recently it has been demonstrated that vascular endothelial growth factor (VEGF) or vascular permeability factor is essential for tumour angiogenesis. Its role in inflammation-mediated angiogenesis has yet to be determined. In this study, the murine chronic granulomatous air pouch model was used to investigate the role of VEGF in angiogenesis. Animals were treated twice weekly with 10 μ g per animal of neutralizing antibody to rh VEGF and the vascularity and granuloma dry weight were assessed after 7 days. This resulted in significant suppression of both angiogenesis and granuloma dry weight. Western blot analysis demonstrated the presence of VEGF; the levels of protein paralleled the angiogenic response. These results demonstrate for the first time that VEGF may be an important regulator of angiogenesis in inflammation. 相似文献
58.
ANNE G.M. SCHILDER JEANNETTE G. VAN MANEN GERHARD A. ZIELHUIS EEFJE H. GRIEVINK SYLVIA A.F. PETERS PAUL VAN DEN BROEK 《Clinical otolaryngology》1993,18(3):234-241
The long-term effects of early OME on language and educational attainment were studied in 47 children of 7–8 years of age who had participated in earlier pre-school study1 on otitis media with effusion (OME) and language development. At pre-school age OME was diagnosed by quarterly tympanometric screens (maximum nine) and language was assessed by a standard Reynell gtest. At school age the ears of the children were assessed by otomicroscopy, tympanometry and audiometry, and the development status by several language, reading and spelling tests. The association between early OME and language development found at pre-school age was no longer present at school age. 相似文献
59.
60.
PHILIPPE MAURY M.D. EMILIE THOMSON M.D. ANNE ROLLIN M.D. MATHIEU BERRY M.D. THOMAS COGNET M.D. ALEXANDRE DUPARC M.D. PIERRE MONDOLY M.D. MATHIEU GAUTIER M.D. OLIVIER LAIREZ M.D. SIMON MÉJEAN M.D. PIERRE MASSABUAU M.D. CHRISTELLE CARDIN M.D. STÉPHANE COMBES M.D. JEAN‐PAUL ALBENQUE M.D. NICOLAS COMBES M.D. 《Pacing and clinical electrophysiology : PACE》2015,38(5):617-624