全文获取类型
收费全文 | 1777篇 |
免费 | 69篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 41篇 |
妇产科学 | 25篇 |
基础医学 | 384篇 |
口腔科学 | 25篇 |
临床医学 | 212篇 |
内科学 | 426篇 |
皮肤病学 | 42篇 |
神经病学 | 66篇 |
特种医学 | 68篇 |
外科学 | 146篇 |
综合类 | 11篇 |
预防医学 | 75篇 |
眼科学 | 18篇 |
药学 | 152篇 |
中国医学 | 6篇 |
肿瘤学 | 139篇 |
出版年
2022年 | 22篇 |
2021年 | 59篇 |
2020年 | 23篇 |
2019年 | 19篇 |
2018年 | 33篇 |
2017年 | 23篇 |
2016年 | 30篇 |
2015年 | 30篇 |
2014年 | 46篇 |
2013年 | 77篇 |
2012年 | 112篇 |
2011年 | 106篇 |
2010年 | 68篇 |
2009年 | 79篇 |
2008年 | 103篇 |
2007年 | 105篇 |
2006年 | 102篇 |
2005年 | 97篇 |
2004年 | 94篇 |
2003年 | 77篇 |
2002年 | 71篇 |
2001年 | 24篇 |
2000年 | 14篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 20篇 |
1991年 | 11篇 |
1990年 | 10篇 |
1989年 | 17篇 |
1988年 | 16篇 |
1987年 | 15篇 |
1986年 | 8篇 |
1985年 | 25篇 |
1984年 | 11篇 |
1983年 | 21篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1974年 | 10篇 |
1971年 | 8篇 |
1968年 | 9篇 |
1966年 | 8篇 |
排序方式: 共有1850条查询结果,搜索用时 0 毫秒
1.
Thomas L Eggerman Traci Heath Mondoro Jay N Lozier Jaroslav G Vostal 《Human gene therapy》2002,13(1):125-128
Adenoviruses are commonly used as vectors in human clinical gene therapy trials. High doses of intravenous adenovirus vectors have been associated with development of thrombocytopenia of undetermined origin. Viral internalization requires the presence cell surface integrins, alpha(v)beta(3) or alpha(v)beta(5), that can blind ligands with a arginine-glycine-aspartic acid (RGD) sequence. This sequence is found in the adenovirus penton base. Platelets express the alpha(v)beta(3) integrin and other integrins that bind the RGD sequence of ligands such as fibrinogen, laminin, vitronectin, and von Willebrand factor (vWF). Platelet aggregation is mediated, in part, by the binding of the RGD sequence of fibrinogen to a platelet surface integrin, glycoprotein IIb/IIIa (GP IIb/IIIa). We investigated whether adenovirus particles could interfere with or potentiate agonist-induced platelet aggregation. Incubation of platelet-rich plasma with adenovirus under stirred conditions did not promote spontaneous aggregation. The addition of physiological platelet agonists, ADP, collagen, or epinephrine, induced platelet aggregation. However, the presence of adenovirus in a wide range of concentrations did not inhibit or potentiate agonist-induced aggregation. These results suggest that the adenovirus-associated thrombocytopenia observed in vivo is independent of a direct effect of the virus on platelet aggregation. 相似文献
2.
ARH missense polymorphisms and plasma cholesterol levels. 总被引:1,自引:0,他引:1
Mutations in a putative low-density lipoprotein (LDL) receptor adaptor protein called ARH have been recently described in patients with autosomal recessive hypercholesterolemia (ARH). ARH plays a tissue-specific role in determination of LDL receptor function. In the ARH gene three mismatched polymorphisms have been detected: Pro202Ser, Pro202His and Arg238Trp. These are of putative interest in plasma cholesterol level determination. To evaluate the effect of polymorphisms on plasma cholesterol levels, all polymorphisms were analyzed by PCR and restriction enzyme analysis by MnII, HpyCH4IV and SacII in 100 Caucasian males with high (>90%, 6.29 +/- 0.89 mmol/l), and 100 males with low (<10%, 3.60 +/- 0.57 mmol/l), total plasma cholesterol levels. No significant differences were observed in frequencies of ARH genotypes or alleles between these two extreme groups. These results suggest that ARH polymorphisms are unlikely to be important genetic determinants of plasma cholesterol levels. 相似文献
3.
Peter Schnider MD Joachim Maly PhD Josef Grünberger PhD Susanne Aull MD Karl Zeiler MD Peter Wessely MD 《Headache》1995,35(5):269-272
A considerable proportion of headache patients fulfill the criteria of "drug abuse" (definition according to the International Headache Society [IHS] criteria). These patients exhibit markedly reduced vigilance and continuous performance, as shown by the results of critical flicker frequency (CFF) analysis.
The present study deals with the question whether this impairment of vigilance and continuous performance is reversible. Forty-eight headache patients with drug abuse were investigated three times by means of CFF analysis: immediately before (A), immediately after (B), and 3 weeks after having finished (C) inpatient drug withdrawal.
Immediately after withdrawal, a significant decrease of headache intensity was observed. The CFF values, however, remained unchanged at a depressed level, probably due to withdrawal medication and the initial sedative side effects of thymoleptic agents (given as prophylaxis).
Three weeks after withdrawal, however, the CFF values were significantly improved, and were now within a range not far from the normal values known from a healthy general population. Thus, even after many years of drug abuse, headache patients have a good chance to improve their vigilance and continuous performance and to reach normal or close to normal levels. 相似文献
The present study deals with the question whether this impairment of vigilance and continuous performance is reversible. Forty-eight headache patients with drug abuse were investigated three times by means of CFF analysis: immediately before (A), immediately after (B), and 3 weeks after having finished (C) inpatient drug withdrawal.
Immediately after withdrawal, a significant decrease of headache intensity was observed. The CFF values, however, remained unchanged at a depressed level, probably due to withdrawal medication and the initial sedative side effects of thymoleptic agents (given as prophylaxis).
Three weeks after withdrawal, however, the CFF values were significantly improved, and were now within a range not far from the normal values known from a healthy general population. Thus, even after many years of drug abuse, headache patients have a good chance to improve their vigilance and continuous performance and to reach normal or close to normal levels. 相似文献
4.
Iwar Klime Antonian Vraana Jaroslav Kune Elena eboUkovaA Zdena Dobe ovaa Pavel tolba Josef Zicha 《Blood pressure》1995,4(3):137-142
Hereditary hypertriglyceridemic rats (hHTg) were developed as a new genetic model for the study of relationships between blood pressure (BP) and metabolic abnormalities. This strain has been produced by selective inbreeding from Wistar rats according to the rise of plasma triglycerides induced by a high-sucrose diet. Though hHTg rats display hypertriglyceridemia, impaired glucose tolerrance, hyperinsulinemia, insulin resistance and increased BP even without nutritional stimuli, high sucrose feeding further aggravates these symptoms. High plasma triglycerides levels in hHTg rats seem to be a consequence of their hyperproduction. Impaired insulin action is responsible for the defective glucoregulation in this strain. The loss of insulin responsiveness might be due to a reduction in the number of glucose transporters. Highly significant relationships among plasma triglycerides, ouabain-resistant Na+ transport and BP were demonstrated in the hHTg rats. Segregating populations (F2 hybrids) should be used for genetic analysis of the primary role of lipid and/or ion transport abnormalities in the pathogenesis of this form of genetic hypertension. 相似文献
5.
Christian Rüegg Martin Hersberger Barbara Wusk Katharina Rentsch Gerd A Kullak-Ublick Arnold von Eckardstein Friedrich E Maly 《Clinical chemistry and laboratory medicine》2004,42(5):494-498
Crohn's disease is a complex disorder, with multiple genetic traits. A frameshift mutation (Leu1007fsinsC) and two missense mutations (Gly908Arg and Arg702Trp) in the NOD2/CARD15 gene are strongly associated with susceptibility to Crohn's disease. The presence of one of these risk alleles confers a 2- to 4-fold increase in the risk of developing Crohn's disease, and the presence of two mutant alleles increases the risk over 20-fold. To facilitate the analysis of these polymorphisms, we developed three LightCycler assays to detect the missense mutations Arg702Trp and Gly908Arg and the frameshift mutation Leu100fsinsC in the NOD2/ CARD15 gene. All three assays can be run simultaneously on one LightCycler using identical cycling parameters. Analysis of 53 DNAs from Crohn's patients helped to identify carriers at allele frequencies similar to other Caucasian populations. The sequencing of such DNAs confirmed the accuracy of the assays. In conclusion, we present three rapid and robust assays to detect the Arg702Trp, the Gly908Arg and the Leu1007fsinsC ins mutations in the NOD2/CARD15 gene [corrected] 相似文献
6.
Jaroslav Blahoš 《Wiener Medizinische Wochenschrift》2007,157(23-24):589-592
7.
Jaroslav Salamoun Jo
rg Remien 《Journal of pharmaceutical and biomedical analysis》1992,10(10-12):931-936
The inhibiting compounds were separated by micro-column liquid chromatography in the mobile phase containing the natural substrate acetylcholine. A home-made packed bed microbioreactor system containing immobilized enzyme acetylcholinesterase (ACHE) in human red blood cell membrane and choline oxidase (CHO) from alcaligenes was used for the post-column conversion of acetylcholine to hydrogen peroxide which was detected by an electrochemical detector. The inhibition effect of the solutes caused a decrease in the acetylcholinesterase activity, a decrease in the formation of hydrogen peroxide and also a decrease in the response corresponding to the concentration of the solutes. The rate of the enzyme regeneration was also recorded. The micro-system was compared with a conventional LC system comprising commercially prepared enzyme reactor. The stability of the enzymes is at least 3 weeks at ambient temperature. The limit of detection depends on biological activity of inhibition and for galanthamine was 1 pmol. 相似文献
8.
Hypertension due to chronic inhibition of NO synthase (NOS) by Nomega-nitro-L-arginine methyl ester (L-NAME) administration is characterized by both impaired NO-dependent vasodilation and enhanced sympathetic vasoconstriction. The aim of our study was to evaluate changes in the participation of major vasoactive systems in L-NAME-treated rats which were subjected to simultaneous antihypertensive (captopril) or antioxidant (N-acetylcysteine, NAC) treatment. Three-month-old Wistar males treated with L-NAME (60 mg/kg/day) for 5 weeks were compared to rats in which L-NAME treatment was combined with simultaneous chronic administration of captopril or NAC. Basal blood pressure (BP) and its acute responses to consecutive i.v. injections of captopril (10 mg/kg), pentolinium (5 mg/kg), L-NAME (30 mg/kg), tetraethylammonium (TEA, 16 mg/kg) and nitroprusside (NP, 20 microg/kg) were determined in conscious rats at the end of the study. The development of L-NAME hypertension was prevented by captopril treatment, whereas NAC treatment caused only a moderate BP reduction. Captopril treatment normalized the sympathetic BP component and significantly reduced residual BP (measured at full NP-induced vasodilation). In contrast, chronic NAC treatment did not modify the sympathetic BP component or residual BP, but significantly enhanced NO-dependent vasodilation. Neither captopril nor NAC treatment influenced the compensatory increase of TEA-sensitive vasodilation mediated by endothelium-derived hyperpolarizing factor in L-NAME-treated rats. Chronic captopril treatment prevented L-NAME hypertension by lowering of sympathetic tone, whereas chronic NAC treatment attenuated L-NAME hypertension by reduction in the vasodilator deficit due to enhanced NO-dependent vasodilation. 相似文献
9.
Sandra Lobo Jaroslav Cervenka Arnold London Mary Ella M. Pierpont 《American journal of medical genetics. Part A》1992,43(4):701-703
We report on a patient with interstitial deletion of 10q and compare her to 8 previously described patients, 2 of whom have chromosomal breakpoints similar to our patient. Minor anomalies including broad forehead, hypertelorism, strabismus, prominent philtrum, and “dysplastic” pinnae are present in our patient. Psychomotor retardation and hypotonia are universal findings in 10q interstitial deletion. Growth retardation, not present in our patient, is seen in some. These clinical findings are sufficiently distinct to suggest early chromosome studies. © 1992 Wiley-Liss, Inc. 相似文献
10.
1H and 13C NMR signals of tri(propylene glycol) and of its benzoate and phenyl urethane were assigned by means of 1D and 2D NMR methods such as super-selective long-range INEPT, H-H COSY, H-C COSY and H-H-C RCT spectra. Both 1H and 13C NMR were used as methods for the determination of primary and secondary hydroxy end-groups and of their degree of conversion. 13C NMR was found to be a reliable and universal method of end-group determination even for cases where 1H NMR fails due to the presence of water in the sample or to the nature of the reactant. The results are applied to the analysis of poly(oxypropylene)s with two or three hydroxy end-groups and their derivatives. 相似文献