全文获取类型
收费全文 | 1583篇 |
免费 | 121篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 45篇 |
妇产科学 | 38篇 |
基础医学 | 295篇 |
口腔科学 | 5篇 |
临床医学 | 134篇 |
内科学 | 320篇 |
皮肤病学 | 42篇 |
神经病学 | 113篇 |
特种医学 | 44篇 |
外科学 | 221篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 126篇 |
眼科学 | 10篇 |
药学 | 119篇 |
中国医学 | 9篇 |
肿瘤学 | 120篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 16篇 |
2021年 | 38篇 |
2020年 | 16篇 |
2019年 | 41篇 |
2018年 | 40篇 |
2017年 | 30篇 |
2016年 | 37篇 |
2015年 | 34篇 |
2014年 | 53篇 |
2013年 | 72篇 |
2012年 | 119篇 |
2011年 | 148篇 |
2010年 | 82篇 |
2009年 | 64篇 |
2008年 | 105篇 |
2007年 | 108篇 |
2006年 | 112篇 |
2005年 | 98篇 |
2004年 | 107篇 |
2003年 | 85篇 |
2002年 | 84篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 20篇 |
1998年 | 19篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1971年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1714条查询结果,搜索用时 0 毫秒
31.
32.
Urinary complications and risk factors in symptomatic multiple sclerosis patients. Study of a cohort of 328 patients 下载免费PDF全文
33.
Lopman B Vennema H Kohli E Pothier P Sanchez A Negredo A Buesa J Schreier E Reacher M Brown D Gray J Iturriza M Gallimore C Bottiger B Hedlund KO Torvén M von Bonsdorff CH Maunula L Poljsak-Prijatelj M Zimsek J Reuter G Szücs G Melegh B Svennson L van Duijnhoven Y Koopmans M 《Lancet》2004,363(9410):682-688
34.
Evelyne Roux Nicole Romquin Maryvonne Laurent François Regnault 《Acta diabetologica》1977,14(5-6):185-191
Summary Among the different factors which could be responsible for the retinal vascular disturbances in diabetic retinopathy, we have
investigated platelet populations, sialic acid content of platelets and collagen-induced platelet aggregation. The following
results were obtained: a) there was no modification of platelet population distribution except for population A; b) there
was a modification of collagen-induced platelet aggregation; the lag time was increased in diabetics. 相似文献
35.
Lamoussa Paul Ouattara Souleymane Sanon Valérie Mahiou-Leddet Adama Gansané Béatrice Baghdikian Abdoulaye Traoré Issa Nébié Alfred S. Traoré Nadine Azas Evelyne Ollivier Sodiomon Bienvenu Sirima 《Parasitology research》2014,113(1):405-416
Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum drug resistance. There is an urgent need to investigate new sources of antimalarial drugs which are more effective against Plasmodium falciparum. One of the potential sources of antimalarial drugs is traditional medicinal plants. In this work, we studied the in vitro antiplasmodial activity of chloromethylenic, methanolic, and MeOH/H2O (1/1) crude extracts and decoction obtained from eight medicinal plants collected in Burkina Faso and of total alkaloids for five plants. Extracts were evaluated in vitro for efficacy against Plasmodium falciparum strain K1, which is resistant to chloroquine, pyrimethamine and proguanil using the fluorescence-based SYBR Green I assay. The antiproliferative activity on human-derived hepatoma cell line HepG2 and Chinese hamster ovary (CHO) cells was evaluated using the 3-[4,5-dimethylthyazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test in order to determine the selectivity index. Among the plant extracts tested for in vitro antiplasmodial activity, 16 were considered to be inactive (with IC50?>?10 μg/ml), six showed a moderate activity (5?<?IC50?≤?10 μg/ml), and six were found to have a good in vitro activity with IC50 value?≤?5 μg/ml. The highest antiplasmodial activity was found for extracts from: the alkaloid leaf extract and the chloromethylenic extracts of Combretum fragrans (IC50?=?3 μg/ml, IC50?=?5 μg/ml), the total alkaloids and the chloromethylenic leaf extracts of Combretum collinum (IC50?=?4 μg/ml), the MeOH/H2O leaf extract of Terminalia avicennioides (IC50?=?3.5 μg/ml), and the alkaloid leaf extract of Pavetta crassipes (IC50?=?5 μg/ml). Three other extracts showed moderate antiplasmodial activity (5?<?IC50?≤?10 μg/ml): Terminalia avicennioides and Combretum fragrans methanolic extracts and Acacia kirkii alkaloid leaf extract (IC50?=?6.5, 9 and 10 μg/ml respectively). The Terminalia avicennioides crude MeOH/H2O (80:20 v/v) extract of the leaves was submitted to a successive liquid/liquid extraction with ethylacetate and n-butanol respectively. The extracts were investigated for in vitro antiplasmodial activity and antioxidant properties using DPPH●, ABTS+ and FRAP methods. The ethylacetate extract showed the best antiplasmodial activity (7 μg/ml) and the active constituent was isolated as ellagic acid by bioguided fractionation with an IC50?=?0.2 μM on Plasmodium falciparum and SI?=?152. Besides, Terminalia avicennioides leaf extract and ellagic acid showed a good antioxidant activity. Our finding confirms the importance of investigating the antimalarial activity of plant species used in traditional medicine. Overall, two plants belonging to the Combretaceae family, Combretum fragrans and Combretum collinum appeared to be the best candidates and will be further investigated for their antiplasmodial properties, in order to isolate the molecules responsible for the antiplasmodial activity. 相似文献
36.
37.
38.
Grisafi D Tassone E Dedja A Oselladore B Masola V Guzzardo V Porzionato A Salmaso R Albertin G Artusi C Zaninotto M Onisto M Milan A Macchi V De Caro R Fassina A Bordigato MA Chiandetti L Filippone M Zaramella P 《Lung》2012,190(4):419-430
Background
Moderate normobaric hyperoxia causes alveolar and vascular lung derangement in the newborn rat. Endogenous nitric oxide (NO), which promotes lung growth, is produced from the metabolism of l-arginine to l-citrulline in endothelial cells. We investigated whether administering l-citrulline by raising the serum levels of l-arginine and enhancing NO endogenous synthesis attenuates moderate hyperoxia-induced lung injury.Methods
Newborn rats were exposed to FiO2?=?0.6 or room air for 14?days to induce lung derangement and then were administered l-citrulline or a vehicle (sham). Lung histopathology was studied with morphometric features. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected for analysis. Lung vascular endothelial growth factor (VEGF), nitric oxide synthase (eNOS), and matrix metalloproteinase 2 (MMP2) gene and protein expressions were assessed.Results
Serum l-arginine rose in the L-citr?+?hyperoxia group (p?=?0.05), as well as the Von Willebrand factor stained vessels count (p?=?0.0008). Lung VEGF immune staining, localized on endothelial cells, was weaker in the sections under hyperoxia than the l-citr?+?hyperoxia and room air groups. This pattern was comparable with the VEGF gene and protein expression profiles. Mean alveolar size increased in the untreated hyperoxia and sham-treated groups compared with the groups reared in room air or treated with l-citrulline under exposure to hyperoxia (p?=?0.0001). Lung VEGF and eNOS increased in the l-citrulline-treated rats, though this treatment did not change MMP2 gene expression but regulated the MMP2 active protein, which rose in BALF (p?=?0.003).Conclusions
We conclude that administering l-citrulline proved effective in improving alveolar and vascular growth in a model of oxygen-induced pulmonary damage, suggesting better lung growth and matrix regulation than in untreated groups. 相似文献39.
Françoise Houdayer Marcela Gargiulo Martine Frischmann Audrey Labalme Evelyne Decullier Marie-Pierre Cordier Sophie Dupuis-Girod Gaetan Lesca Marianne Till Damien Sanlaville Patrick Edery Massimiliano Rossi 《European journal of medical genetics》2013,56(11):585-590
This qualitative study aims to describe the psychological impact of the diagnosis announcement of pathogenic Copy Number Variations (pCNVs). We performed semi-structured interviews of 60 parents of 41 affected children and 5 geneticists who announced the diagnoses. The diagnosis of the best characterized microdeletion syndromes, often defined by patronymic names (e.g. Williams syndrome), is generally made on a clinical basis by geneticists and confirmed by fluorescence in situ hybridization analysis. Chromosomal microarray, on the contrary, can allow the disclosure of rare pCNVs named after cytogenetic formulas, with poorly known clinical consequences: this makes doctors feel less confident with these diagnosis announcements. The disclosure of pCNVs named after cytogenetic formulas does not facilitate the parental mental representation of the disease, leading some parents to call into question the genotype-phenotype correlation or the very notion of a diagnosis. The announcement of inherited pCNVs can increase the feeling of parental guilt; the disclosure of de novo pCNVs can induce a feeling of “breakage” in the mental representation of the parent-child vertical transmission. In conclusion, our study shows that the disclosure of pCNVs has a significant psychological impact: a multidisciplinary approach to the diagnosis announcement, including a psychological support, should be systematically warranted. 相似文献
40.