全文获取类型
收费全文 | 5985篇 |
免费 | 356篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 93篇 |
妇产科学 | 144篇 |
基础医学 | 1096篇 |
口腔科学 | 707篇 |
临床医学 | 368篇 |
内科学 | 1069篇 |
皮肤病学 | 132篇 |
神经病学 | 498篇 |
特种医学 | 141篇 |
外科学 | 498篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 675篇 |
眼科学 | 58篇 |
药学 | 482篇 |
中国医学 | 57篇 |
肿瘤学 | 262篇 |
出版年
2024年 | 6篇 |
2023年 | 51篇 |
2022年 | 131篇 |
2021年 | 179篇 |
2020年 | 124篇 |
2019年 | 172篇 |
2018年 | 229篇 |
2017年 | 153篇 |
2016年 | 179篇 |
2015年 | 201篇 |
2014年 | 289篇 |
2013年 | 320篇 |
2012年 | 477篇 |
2011年 | 549篇 |
2010年 | 274篇 |
2009年 | 207篇 |
2008年 | 375篇 |
2007年 | 398篇 |
2006年 | 295篇 |
2005年 | 312篇 |
2004年 | 248篇 |
2003年 | 219篇 |
2002年 | 165篇 |
2001年 | 121篇 |
2000年 | 115篇 |
1999年 | 109篇 |
1998年 | 54篇 |
1997年 | 38篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 21篇 |
1993年 | 20篇 |
1992年 | 51篇 |
1991年 | 36篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1979年 | 11篇 |
1977年 | 4篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1971年 | 6篇 |
1969年 | 5篇 |
1965年 | 5篇 |
排序方式: 共有6368条查询结果,搜索用时 29 毫秒
61.
The placenta forms a selective barrier that is able to transport nutrients that are of critical use to the fetus. Delivery of essential fatty acids to the fetus is dependent upon transplacental transport and provides the backbone for the biosynthesis of biological membranes, myelin and various signalling molecules. The primary objective of this research was to elucidate the expression patterns of genes that regulate fatty acid transport across the placenta. Several fatty acid transport regulatory genes have been identified in the rat including; cytoplasmic heart fatty acid binding protein (hFABP), plasma membrane fatty acid binding protein (FABPpm), fatty acid translocase (FAT) and fatty acid transport protein (FATP). In this study, we have elucidated temporal and spatial expression patterns for these genes in the rat placenta and in cell culture models of the rat placenta by Northern blot, RT-PCR, Western blot and/or by in situ hybridization analyses. Expression of hFABP was specific to the labyrinth zone, the main barrier and site of transplacental transport in the rat placenta. In addition, the levels of hFABP expression increased with gestational age, suggesting a growing requirement for fatty acid transport with advancing stages of pregnancy. FABPpm, FAT and FATP are expressed in both the junctional and labyrinth zones of the rat placenta. FAT was predominantly localized to the labyrinth zone by in situ hybridization analysis. The placental cell expression patterns of the genes involved in fatty acid transport were supported by our observations of HRP-1 (labyrinth zone) and Rcho-1 (junctional zone) trophoblast cell culture models. Given their cell surface location, we predict that FABPpm, FAT and FATP potentially participate in placental fatty acid uptake. The predominant expression of hFABP and FAT in the labyrinth zone of the chorioallantoic placenta implicates hFABP and FAT in the transplacental movement of fatty acids from maternal to fetal compartments. 相似文献
62.
Rennan Garcias Moreira Julia Maria SaraivaDuarte Alexandre Costa Pereira Martha SosaMacias Carlos GalavizHernandez Meddly Lesley Santolalla Wagner C. S. Magalhes Camila Zolini Thiago Peixoto Leal Zsolt Balzs Adrin Llerena Robert H. Gilman Jos Geraldo Mill Victor Borda Heinner Guio Timothy D. OConnor Eduardo TarazonaSantos Fernanda RodriguesSoares 《CTS Clinical and Translational Science》2022,15(6):1400
63.
64.
65.
66.
Dallago CM Abech DD Pereira-Lima JF Leães CG Batista RL Trarbach EB Oliveira Mda C 《Pituitary》2008,11(1):109-112
Kallmann syndrome (KS) is a developmental disease characterized by the association of isolated hypogonadotropic hypogonadism
and anosmia/hyposmia. We report an unusual presentation of two females with KS and empty sella. These females, aged at 20
and 29-year-old, presented primary amenorrhea with prepubertal estradiol and low gonadotropin levels. No other significant
clinical signs were observed. Empty sella was observed on MRI in both cases. Sequencing of FGFR1 gene, recently implicated in autosomal form of KS, was performed and one splicing mutation (IVS14 + 1G > A) was identified
in one patient. 相似文献
67.
68.
José Alexandre da Rocha Curvelo Anna Lea Silva Barreto Camila A. dos Anjos Rafaela S. Santana Ariadne Nunes Alonso Maria Teresa Vilela Romanos Kelly C. G. de Moura Paula Fernandes Carneiro Maristela Barbosa Portela Maria do Carmo F. R. Pinto Rosangela Maria de Araújo Soares 《Medicinal chemistry research》2015,24(3):1155-1161
69.
Izabela Guimar?es Barbosa Natália Pessoa Rocha Frankcinéia Assis érica Leandro Marciano Vieira Jair C Soares Moises Evandro Bauer Ant?nio Lúcio Teixeira 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2015,18(1)
Background:
This study tested the hypothesis that the low-grade inflammation presented in patients with bipolar disorder (BD) is associated with expansion of activated T cells, and this activated state may be due to a lack of peripheral regulatory cells.Methods:
Specifically, we investigated the distribution of monocytes and lymphocyte subsets, and investigated Th1/Th2/Th17 cytokines in plasma by flow cytometry. Twenty-one BD type I patients and 21 age- and sex-matched controls were recruited for this study.Results:
BD patients had increased proportions of monocytes (CD14+). Regarding lymphocyte populations, BD patients presented reduced proportions of T cells (CD3+) and cytotoxic T cells (CD3+CD8+). BD patients also exhibited a higher percentage of activated T CD4+CD25+ cells, and a lower percentage of IL-10 expressing Treg cells.Conclusions:
Our data shed some light into the underlying mechanisms involved with the chronic low-grade inflammatory profile described in BD patients. 相似文献70.
Sensory and inflammatory colonic changes induced by vincristine in distinct rat models of colitis 下载免费PDF全文
M. T. B. Silva A. A. Peixoto‐Junior L. S. Marinho N. S. Matias P. M. G. Soares A. A. Santos G. A. C. Brito F. H. Rola F. de A. A. Gondim 《Autonomic & autacoid pharmacology》2015,34(3-4):27-34
Preclinical and clinical studies show that gastrointestinal (GI) inflammation can evoke sensory changes occasionally far from the original inflammatory site. Animal models of colitis with either trinitrobenzenesulphonic acid (TNBS) or mustard oil (MO) produce distinct patterns of somatic and visceral sensory changes. We evaluated the effects of four doses of i.v. vincristine 150 μg kg?1 (total of 600 μg kg?1) treatment on the somatic (thermal nociceptive threshold) and colonic (morphological) changes induced by TNBS or MO in rats. TNBS and MO groups were further submitted to vincristine or saline pretreatments. TNBS induced somatic hypersensitivity, while MO induced somatic hyposensitivity (P < 0.05) when compared to the saline and ethanol control groups. Vincristine per se induced somatic hypersensitivity (P < 0.05). This effect was enhanced by TNBS and reversed by MO treatments. Although vincristine increased the colitis area (colonic weight length?1 ratio) and the Morris' score in TNBS‐treated rats, it did not alter the colitis area and even lowered the Morris' score in MO‐treated rats. Compared to the saline (control) group, vincristine did not alter the colonic microscopic pattern. However, such lesions scores are higher (P < 0.05) in colitis groups induced by TNBS and MO, pretreated or not with vincristine. In conclusion, the somatic changes induced by different models of experimental colitis are diverse and modulated differently by vincristine. 相似文献