全文获取类型
收费全文 | 1013篇 |
免费 | 48篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 1篇 |
妇产科学 | 1篇 |
基础医学 | 119篇 |
口腔科学 | 4篇 |
临床医学 | 16篇 |
内科学 | 161篇 |
皮肤病学 | 105篇 |
神经病学 | 35篇 |
特种医学 | 9篇 |
外科学 | 102篇 |
综合类 | 84篇 |
预防医学 | 172篇 |
眼科学 | 2篇 |
药学 | 113篇 |
中国医学 | 172篇 |
肿瘤学 | 25篇 |
出版年
2024年 | 1篇 |
2023年 | 26篇 |
2022年 | 28篇 |
2021年 | 70篇 |
2020年 | 51篇 |
2019年 | 80篇 |
2018年 | 48篇 |
2017年 | 51篇 |
2016年 | 30篇 |
2015年 | 38篇 |
2014年 | 69篇 |
2013年 | 84篇 |
2012年 | 61篇 |
2011年 | 69篇 |
2010年 | 48篇 |
2009年 | 53篇 |
2008年 | 38篇 |
2007年 | 38篇 |
2006年 | 36篇 |
2005年 | 38篇 |
2004年 | 20篇 |
2003年 | 24篇 |
2002年 | 17篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 2篇 |
排序方式: 共有1122条查询结果,搜索用时 31 毫秒
21.
22.
23.
J.L. Guil‐Guerrero 《Ecology of food and nutrition》2013,52(5):481-495
Analyses of the nutrients are given for the leaves of wild Plantago major L., P. lanceolata L. and P. media L., from different locations of the southeast of Spain. The proximate composition, mineral elements (Na, K, Ca, Mg, Fe, Cu, Zn, Mn and P), fatty acids, vitamins (vitamin C and carotenes), nitrate and oxalic acid were determined. The results show the low proportion of available carbohydrates, ranging from 1.99 g (P. major) to 2.81 g (P. lanceolata) (per 100 g fresh weight). Oxalic acid was found in low amounts, between 33.5 mg (P. media) and 88.2 mg (P. lanceolata) (100 g f wt). P. major had the highest amounts of vitamin C (45.1 mg/100g f. wt.) and calcium (108mg/100g f. wt.). Polyunsaturated fatty acids were high in all species, ranging from 38.97% (P. media) to 46.07% (P. lanceolata). Nutrient ratios (K/Na; Ca/P and oxalic acid/Ca) were found to be favourable in most cases. 相似文献
24.
Min Yang Anup Ramachandran Hui-Min Yan Benjamin L. Woolbright Bryan L. Copple Peter Fickert Michael Trauner Hartmut Jaeschke 《Toxicology letters》2014
Osteopontin (OPN) is a chemotactic factor which can be cleaved to the pro-inflammatory form by matrix metalloproteinases (MMPs). To test the hypothesis that OPN can modulate inflammatory liver injury during cholestasis, wild-type (WT) C57BL/6 and OPN knockout (OPN-KO) mice underwent bile duct ligation (BDL). OPN-KO mice showed significant reduction in liver injury (plasma ALT and necrosis) and neutrophil recruitment compared with WT animals at 24 h but not 72 h after BDL. In WT mice, a 4-fold increase in hepatic MMP-3 mRNA and elevated MMP activities and cleaved OPN levels were observed in bile. WT mice subjected to BDL in the presence of the MMP inhibitor BB-94 showed reduced liver injury, less neutrophil extravasation and diminished levels of cleaved OPN in bile. Thus, during obstructive cholestasis, OPN released from biliary epithelial cells could be cleaved by MMPs in bile. When the biliary system leaks, cleaved OPN enters the parenchyma and attracts neutrophils. In the absence of OPN, other chemoattractants, e.g. chemokines, mediate a delayed inflammatory response and injury. Taken together, our data suggest that OPN is the pro-inflammatory mediator that initiates the early neutrophil-mediated injury phase during obstructive cholestasis in mice. 相似文献
25.
Background
In utero exposure to arsenic is known to adversely affect reproductive outcomes. Evidence of arsenic teratogenicity varies widely and depends on individual genotypic differences in sensitivity to As. In this study, we investigated the potential interaction between 5,10-methylenetetrahydrofolate reductase (Mthfr) genotype and arsenic embryotoxicity using the Mthfr knockout mouse model.Methods
Pregnant dams were treated with sodium arsenate, and reproductive outcomes including: implantation, resorption, congenital malformation and fetal birth weight were recorded at E18.5.Results
When the dams in Mthfr+/− × Mthfr+/− matings were treated with 7.2 mg/kg As, the resorption rate increased to 43.4%, from a background frequency of 7.2%. The As treatment also induced external malformations (40.9%) and significantly lowered the average fetal birth weight among fetuses, without any obvious toxic effect on the dam. When comparing the pregnancy outcomes resulting from different mating scenarios (Mthfr+/+ × Mthfr+/−, Mthfr+/− × Mthfr+/− and Mthfr−/− × Mthfr+/−) and arsenic exposure; the resorption rate showed a linear relationship with the number of null alleles (0, 1 or 2) in the Mthfr dams. Fetuses from nullizygous dams had the highest rate of external malformations (43%) and lowest average birth weight. When comparing the outcomes of reciprocal matings (nullizygote × wild-type versus wild-type × nullizygote) after As treatment, the null dams showed significantly higher rates of resorptions and malformations, along with lower fetal birth weights.Conclusions
Maternal genotype contributes to the sensitivity of As embryotoxicity in the Mthfr mouse model. The fetal genotype, however, does not appear to affect the reproductive outcome after in utero As exposure. 相似文献26.
Sunil Veeravalli Bilal A. Omar Lyndsey Houseman Matthew Hancock Sandra G. Gonzalez Malagon Flora Scott Azara Janmohamed Ian R. Phillips Elizabeth A. Shephard 《Biochemical pharmacology》2014
Flavin-containing monooxygenases (FMOs) of mammals are thought to be involved exclusively in the metabolism of foreign chemicals. Here, we report the unexpected finding that mice lacking Fmos 1, 2 and 4 exhibit a lean phenotype and, despite similar food intake, weigh less and store less triglyceride in white adipose tissue (WAT) than wild-type mice. This is a consequence of enhanced whole-body energy expenditure, due mostly to increased resting energy expenditure (REE). This is fuelled, in part, by increased fatty acid β-oxidation in skeletal muscle, which would contribute to depletion of lipid stores in WAT. The enhanced energy expenditure is attributed, in part, to an increased capacity for exercise. There is no evidence that the enhanced REE is due to increased adaptive thermogenesis; instead, our results are consistent with the operation in WAT of a futile energy cycle. In contrast to FMO2 and FMO4, FMO1 is highly expressed in metabolic tissues, including liver, kidney, WAT and BAT. This and other evidence implicates FMO1 as underlying the phenotype. The identification of a novel, previously unsuspected, role for FMO1 as a regulator of energy homeostasis establishes, for the first time, a role for a mammalian FMO in endogenous metabolism. Thus, FMO1 can no longer be considered to function exclusively as a xenobiotic-metabolizing enzyme. Consequently, chronic administration of drugs that are substrates for FMO1 would be expected to affect energy homeostasis, via competition for endogenous substrates, and, thus, have important implications for the general health of patients and their response to drug therapy. 相似文献
27.
Yoshihiro Wakayama Satoshi Hirako Tetsuo Ogawa Takahiro Jimi Seiji Shioda 《ACTA HISTOCHEMICA ET CYTOCHEMICA》2014,47(1):27-33
Aquaporin (AQP) is suggested to be regulated by leptin through the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin pathway. AQP7 and AQP9 are membrane proteins with water and glycerol channels, the latter of which is essential for triglyceride synthesis. We conjectured that the expression of AQP7 and AQP9 would be altered in the skeletal myofibers in obese leptin deficient ob/ob mice as compared with that of wild mice. RNA and protein levels were studied in the quadriceps femoris muscles of ob/ob and wild mice. Real time quantitative RT-PCR analysis showed that mouse AQP7 mRNA levels in skeletal muscles were significantly higher in ob/ob mice than in wild mice (P<0.01), whereas mouse AQP9 mRNA level was not different between the two groups (P>0.05). Histologically the type 1 myofibers of ob/ob mice contained numerous lipid droplets in oil red O stain samples. Immunohistochemical staining of ob/ob mouse muscles revealed enhanced expression of AQP7 at myofiber surface membranes, while AQP9 expression appeared to be similar to that of wild mice. The findings suggest that the upregulated expression of AQP7 in ob/ob mouse muscles facilitates the secretion of glycerol from myocytes. 相似文献
28.
29.
30.
Saireudee Chaturantabut Arkadi Shwartz Kimberley J. Evason Andrew G. Cox Kyle Labella Arnout G. Schepers Song Yang Mariana Acuña Yariv Houvras Liliana Mancio-Silva Shannon Romano Daniel A. Gorelick David E. Cohen Leonard I. Zon Sangeeta N. Bhatia Trista E. North Wolfram Goessling 《Gastroenterology》2019,156(6):1788-1804.e13