全文获取类型
收费全文 | 4992篇 |
免费 | 257篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 228篇 |
儿科学 | 152篇 |
妇产科学 | 145篇 |
基础医学 | 661篇 |
口腔科学 | 21篇 |
临床医学 | 397篇 |
内科学 | 1370篇 |
皮肤病学 | 81篇 |
神经病学 | 398篇 |
特种医学 | 91篇 |
外科学 | 596篇 |
综合类 | 35篇 |
一般理论 | 2篇 |
预防医学 | 252篇 |
眼科学 | 123篇 |
药学 | 427篇 |
中国医学 | 2篇 |
肿瘤学 | 292篇 |
出版年
2023年 | 20篇 |
2022年 | 111篇 |
2021年 | 271篇 |
2020年 | 79篇 |
2019年 | 103篇 |
2018年 | 153篇 |
2017年 | 108篇 |
2016年 | 99篇 |
2015年 | 108篇 |
2014年 | 163篇 |
2013年 | 247篇 |
2012年 | 356篇 |
2011年 | 418篇 |
2010年 | 202篇 |
2009年 | 169篇 |
2008年 | 298篇 |
2007年 | 326篇 |
2006年 | 342篇 |
2005年 | 350篇 |
2004年 | 315篇 |
2003年 | 284篇 |
2002年 | 247篇 |
2001年 | 46篇 |
2000年 | 51篇 |
1999年 | 47篇 |
1998年 | 38篇 |
1997年 | 21篇 |
1996年 | 20篇 |
1995年 | 17篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 22篇 |
1991年 | 20篇 |
1990年 | 14篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1971年 | 6篇 |
1966年 | 5篇 |
排序方式: 共有5273条查询结果,搜索用时 31 毫秒
11.
Marek Szolkiewicz Elzbieta Sucajtys Wojciech Wolyniec Przemyslaw Rutkowski Ewa Stelmanska Justyna Korczynska Julian Swierczynski Boleslaw Rutkowski 《Journal of renal nutrition》2005,15(1):166-172
OBJECTIVE: Hyperlipidemia is a permanent finding in advanced renal failure. It is supposed to be responsible for the accelerated arteriosclerosis and cardiovascular complications observed in patients with that disease. The background is partially determined, however, our knowledge in this matter is not yet satisfactory. METHODS: This study is based on the experimental rat model of chronic renal failure (CRF). Considering white adipose tissue (WAT) lipogenesis upregulation in CRF, along with the determination of acetyl coenzyme A carboxylase (ACC) and fatty acid synthase (FAS) genes expression, we have measured WAT gene expression for sterol regulatory binding protein 1 (SREBP-1) at the level of protein mass and mRNA abundance. Furthermore, we have determined glucose uptake, glucose-to-CO 2 conversion rate, and glucose translocator (GLUT-4) gene expression in WAT. RESULTS: Upregulation of both FAS and ACC gene expression was found in WAT of CRF rats. It was accompanied by WAT SREBP-1 gene overexpression. Moreover, we have observed the increased glucose uptake, glucose to CO 2 conversion rate, and GLUT-4 gene expression in WAT of CRF rats in comparison with controls. CONCLUSION: SREBP-1 gene overexpression may contribute to enhanced lipogenesis upregulation in WAT of CRF rats. It is not excluded that the increased WAT glucose metabolism activity is also induced by this mechanism, although there is no evidence currently to that end. We hypothesize that the increased WAT lipogenesis capacity could be a part of mechanism(s) leading to CRF-induced hyperlipidemia. 相似文献
12.
13.
14.
15.
The present study investigated the specific ways by which cytotoxicity due to glutamate receptor stimulation could be attenuated by the administration of agonists and antagonists of the ionotropic and metabotropic glutamate receptors within the nucleus basalis magnocellularis (NBM) of rats as measured by cortical choline acetyltransferase activity. The results of these studies suggest that (1) the cytotoxicity of ibotenate to NBM cholinergic cells is not dependent upon stimulation of metabotropic glutamate receptors, but results from activation of
(NMDA) receptors, (2) the cytotoxicity of quisqualate to cholinergic cells within the NBM is not dependent upon stimulation of NMDA or metabotropic receptors, and (3) the cytotoxicity of NMDA was prevented by administration (i.p.) of the un-competitive NMDA antagonist memantine (30 mg/kg), resulting in plasma levels of 2.5 μg/ml, a concentration known to block efficiently NMDA receptors in vitro. Finally, performance of a food-motivated, delayed-alternation task on a T-maze was impaired by injections of NMDA into the NBM, but was prevented by co-administration of NMDA with memantine. 相似文献
16.
S Kwiatkowski E Kwiatkowska R Czajka K Ciechanowski K Kedzierska J Bober R Rzepka E Golembiewska D Chlubek 《Hypertension in pregnancy》2006,25(1):37-46
BACKGROUND: Hypertension that develops after 20 gestational weeks and is defined as pregnancy-induced hypertension (PIH). The main cause of PIH is vasoconstriction and the thickening of vascular media, which decreases vascular capacity and increases peripheral resistance. One of the theories postulated to explain this phenomenon is that a transmembrane sodium transport disorder causes an increase in intracellular sodium concentration. In the latest literature, special attention is paid to the role of the increased intracellular sodium concentration in the pathogenesis of essential hypertension (EH). One of the best documented phenotypes for EH is the increased activity of the sodium-proton exchanger (NHE). The aim of this study was to assess if increased NHE activity could be the mechanism responsible for the development of PIH. SUBJECTS AND METHODS: The study included 30 women: 10 pregnant women with PIH after gestational week 30, 10 women with physiological pregnancy after 30 gestational weeks, and 10 healthy non-pregnant women. NHE activity was determined according to Orlov's method as amiloride-sensitive H(+) efflux from acid-loaded cells. RESULTS: The NHE activity in the group of women with PIH was significantly higher than that in women with physiological pregnancy: 10.09 +/- 1.65 vs. 6.81 +/- 2.3 mmol/L RBC/h (p < 0.049) and in the group of non-pregnant women: 10.09 +/- 1.65 vs. 7.56 +/- 1.66 mmol/L RBC/h (p < 0.029). Erythrocyte NHE activity did not differ in the group of women with physiological pregnancy and in the group of non-pregnant women. CONCLUSION: These results seem to suggest that erythrocyte NHE activity is elevated in PIH pregnancies. 相似文献
17.
The aim of this study was to evaluate the influence of female sex hormones on phenazone pharmacokinetics using as an experimental model female rabbits after a bilateral ovariectomy. Eighteen female rabbits divided into two groups: control animals and experimental rabbits, that underwent ovariectomy, were used in the study. Pharmacokinetic assays were performed in all animals: prior to the study, after 1 month and after 2 months. Blood was sampled within 24 hours after intragastric administration of phenazone at a dose 50 mg/kg b.w. Two compartment open model was used for calculations. Significant increase in AUC and prolongation of phenazone halflife as well as a decrease in the total body clearance were noted. The study demonstrated the possible inhibition of the microsomal mixed-function oxidase system by oestrogens. 相似文献
18.
19.
Wojciech Krzysztof Czerwinski 《Macromolecular chemistry and physics.》1993,194(11):3015-3029
The rate of polymerization was described as a function of the monomer concentration of 36 monomer/solvent systems in terms of the reactant-solvent complex (RSC) model. One-, two-and three-parameter optimization procedures were used to fit the rate function to experimental data. Fitting increments were the complex equilibrium constant K and the relative monomer reactivity parameter r11. Irrespective of the optimization procedure, K and r11, were found to correlate with the monomer exponent n and to be K = 0 and r11, = 1 at n = 1. In these cases the RSC model reduces to the classical rate model. Despite the weak character of the monomer (radical)/solvent complexation, this interaction should not be neglected in rate modelling. The RSC model is a convenient tool to describe the chain propagation separately. 相似文献
20.
Development of a multiplex ARMS test for mutations in the HFE gene associated with hereditary haemochromatosis. 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D Baty A Terron Kwiatkowski D Mechan A Harris M J Pippard D Goudie 《Journal of clinical pathology》1998,51(1):73-74
Genetic testing for hereditary haemochromatosis is likely to be a significant workload for diagnostic laboratories. The C282Y and H63D mutations in the HFE gene associated with hereditary haemochromatosis have previously been detected using a number of methods including alterations in the restriction digest pattern of polymerase chain reaction (PCR) amplified products. An amplification refractory mutation system (ARMS) has been developed that will simultaneously detect both hereditary haemochromatosis mutations. Comparison of the results obtained from the analysis of 46 samples referred for hereditary haemochromatosis testing showed no discrepancies between ARMS and restriction enzyme digestion. Furthermore, consistent results were obtained by ARMS from both blood and buccal mouthwash samples. The ARMS test is quicker and less expensive in terms of consumables and scientist time than restriction enzyme analysis, and is therefore suited to the routine diagnostic analysis of hereditary haemochromatosis. 相似文献