全文获取类型
收费全文 | 9869篇 |
免费 | 441篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 184篇 |
妇产科学 | 332篇 |
基础医学 | 1573篇 |
口腔科学 | 208篇 |
临床医学 | 744篇 |
内科学 | 2063篇 |
皮肤病学 | 186篇 |
神经病学 | 1077篇 |
特种医学 | 492篇 |
外国民族医学 | 1篇 |
外科学 | 1239篇 |
综合类 | 52篇 |
一般理论 | 1篇 |
预防医学 | 649篇 |
眼科学 | 140篇 |
药学 | 837篇 |
中国医学 | 23篇 |
肿瘤学 | 462篇 |
出版年
2021年 | 124篇 |
2020年 | 72篇 |
2019年 | 112篇 |
2018年 | 127篇 |
2017年 | 113篇 |
2016年 | 139篇 |
2015年 | 180篇 |
2014年 | 240篇 |
2013年 | 299篇 |
2012年 | 452篇 |
2011年 | 449篇 |
2010年 | 291篇 |
2009年 | 290篇 |
2008年 | 443篇 |
2007年 | 482篇 |
2006年 | 446篇 |
2005年 | 504篇 |
2004年 | 491篇 |
2003年 | 481篇 |
2002年 | 488篇 |
2001年 | 258篇 |
2000年 | 280篇 |
1999年 | 265篇 |
1998年 | 125篇 |
1997年 | 88篇 |
1996年 | 69篇 |
1995年 | 91篇 |
1994年 | 86篇 |
1993年 | 76篇 |
1992年 | 118篇 |
1991年 | 103篇 |
1990年 | 116篇 |
1989年 | 140篇 |
1988年 | 136篇 |
1987年 | 116篇 |
1986年 | 120篇 |
1985年 | 124篇 |
1984年 | 89篇 |
1983年 | 86篇 |
1981年 | 75篇 |
1980年 | 70篇 |
1979年 | 97篇 |
1978年 | 76篇 |
1977年 | 80篇 |
1975年 | 81篇 |
1973年 | 83篇 |
1972年 | 67篇 |
1971年 | 85篇 |
1970年 | 68篇 |
1969年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 906 毫秒
121.
Nikol S Maier A Krausz E Höfling B Huehns TY 《BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy》1998,9(5):375-388
No systemic pharmacological treatment has been convincingly shown to reduce the incidence of restenosis after angioplasty in patients. The lack of success of many pharmaceutical agents in reducing restenosis rates post-angioplasty and following stent implantation, as documented in dozens of clinical trials, has encouraged the development of new biotechnological approaches to the treatment of restenosis. Gene therapy and other agents, including antibodies, fusion toxins and ribozymes, have the potential to prevent some of the sequelae after arterial injury, particularly cell proliferation. Mechanical methods of preventing restenosis, for example sophisticated local drug delivery strategies and biodegradable stents using new materials, in combination with novel therapeutic agents or radiation, may also be of use. 相似文献
122.
Gary T. Shearman Rüdiger Schulz Peter W. Schiller Albert Herz 《Psychopharmacology》1985,85(4):440-443
Rats were trained in a two-lever food-reinforced procedure to discriminate between the effects of saline and the opioid kappa receptor agonist ethylketocyclazocine. After acquisition of this discrimination, generalization tests with opioid peptides such as -endorphin, -neoendorphin, dynorphin A and some dynorphin-derived peptides were conducted. The rats dose-dependently generalized the effects of intracerebroventricularly injected ethylketocyclazocine but not -endorphin, -neoendorphin, dynorphin A1–8, dynorphin A1–13, D-Cys2-L-Cys5-dynorphin A1–13 or dynorphin A.
D-Cys2-L-Cys5-dynorphin A1–13, in contrast to dynorphin A itself, dose-dependently caused analgesia and catatonia that was reversible with naloxone. Studies into the receptor preference of this derivative, using the technique of selective tolerance, revealed that this dynorphin derivative is almost devoid of kappa-receptor activity. 相似文献
123.
Summary The longitudinal muscle-myenteric plexus preparation of the guinea-pig ileum has been employed for the study of the effect of pertussis toxin (IAP) on opioid dependence. Guinea-pigs were treated with IAP (120 g/kg, i.p.) either prior to chronic administration of an opioid or after opioid dependence had been established. The isolated preparations were tested in vitro for dependence; that is, the naloxone-precipitated withdrawal contracture. Naloxone almost failed to evoke a sign of dependence in preparations treated with IAP prior to chronic exposure to an opioid. In contrast, IAP failed to affect the withdrawal contracture when applied to an animal after dependence has been established. It is concluded that theN
i-unit, the substrate for IAP, plays a critical function in the development of dependence. The continuous activation of the opioid receptor associated with the development of dependence may induce changes inN
i which in turn prevent the interaction of IAP with its substrate. 相似文献
124.
Piotr Schulz Szymon Hryhorowicz Anna Maria Rychter Agnieszka Zawada Ryszard Somski Agnieszka Dobrowolska Iwona Krela-Ka
mierczak 《Nutrients》2021,13(2)
The endocannabinoid system (ECS) is an endogenous signaling system formed by specific receptors (cannabinoid type 1 and type 2 (CB1 and CB2)), their endogenous ligands (endocannabinoids), and enzymes involved in their synthesis and degradation. The ECS, centrally and peripherally, is involved in various physiological processes, including regulation of energy balance, promotion of metabolic process, food intake, weight gain, promotion of fat accumulation in adipocytes, and regulation of body homeostasis; thus, its overactivity may be related to obesity. In this review, we try to explain the role of the ECS and the impact of genetic factors on endocannabinoid system modulation in the pathogenesis of obesity, which is a global and civilizational problem affecting the entire world population regardless of age. We also emphasize that the search for potential new targets for health assessment, treatment, and the development of possible therapies in obesity is of great importance. 相似文献
125.
Felix Reichert Maike Schulz Elke Mertens Raskit Lachmann Anton Aebischer 《Emerging infectious diseases》2021,27(6):1693
To validate anecdotal evidence on scabies infestations, we analyzed inpatient and outpatient claims data in Germany. Scabies diagnoses increased 9-fold and treatment failure 4-fold during 2009–2018, driven mainly by persons 15–24 years of age. Prevention and control in young adults appear key because of these persons’ high mobility and social connectivity. 相似文献
126.
We present a heterogeneous non-competitive immunological detection assay for peptide and protein antigens from crude extracts of biological sources. This time-resolved fluoroimmunoassay (TR-FIA) has been designed in a solid-phase mode using 96-well microtiter plates. Using the rare-earth metal europium as a fluorescent marker, a highly sensitive, selective and efficient procedure was developed. This technique prevents from interferences of intrinsic protein fluorescence which is highly important for antigen measurement in complex matrices. The TR-FIA has been applied for the detection of circulating forms of the potential anti-tumor agent endostatin, a C-terminal fragment of collagen XVIII, and its close homolog collagen XV (restin) from hemofiltrate. Endostatin was detected with a limit of detection of 3 ng (150 fmol/well) and a broad dynamic range from 10-1000 ng/well. 相似文献
127.
128.
Ilkka Pörsti Markus Hecker Eberhard Bassenge Rudi Busses 《Naunyn-Schmiedeberg's archives of pharmacology》1993,348(6):650-658
Summary We studied the functional role of angiotensin II (AII) receptor subtypes and vasodilatory endothelial autacoid release in response to AII in isolated perfused rabbit hearts. AII infusion induced biphasic changes in coronary perfusion pressure (CPP): an initial increase was followed by a decrease until a plateau was reached. At higher concentrations of AII (10 nmol/l) this plateau phase was lower than the initial CPP level. AII infusion elicited inverse changes in peak left ventricular pressure (LVP): coronary constriction was associated with a transient decline, and during the plateau phase LVP was clearly increased. AII also moderately augmented prostacyclin (PGI2) release from the coronary vascular bed. The AII-induced changes in CPP, LVP, and PGI2 release were effectively inhibited by the AT1 receptor subtype antagonist ICI D8731 (30 nmol/l), but not by the AT2 receptor antagonist CGP 42112 (30 nmol/l). The adenosine A1 receptor antagonist 8-phenyltheophylline (0.1 mol/l) attenuated the decline in CPP following the constriction phase without affecting the changes in LVP during AII infusion. The cyclooxygenase inhibitor diclofenac (1 mmol/l) had no effect on the AII-induced changes in CPP, whereas the nitric oxide-synthase inhibitor NG-nitro-L-arginine (30 mol/l) markedly potentiated the vasoconstriction but was without effect on the plateau phase of the response. In contrast to AII, the thromboxane analogue U46619 elicited sustained increases in CPP which were associated with slight decreases in LVP.In conclusion, AII induced a biphasic pressor response in the rabbit coronary vascular bed consisting of a transient vasoconstriction followed by a dilatation especially at higher concentrations of AII, an effect which was independent of the endothelial autacoids nitric oxide and PGI2. The AII-induced dilatation probably reflected rapid desensitization of the coronary arterial smooth muscle to the constrictor effect, and the concomitant accumulation of vasodilatory metabolites such as adenosine, generated during the positive inotropic action of AII. All the effects of AII in the rabbit heart appeared to be mediated via the AT, receptor subtype localized on coronary endothelial and smooth muscle cells, as well as on cardiomyocytes.On leave from the Department of Biomedical Sciences, University of Tampere, P.O. Box 607, FIN-33101 Tampere, FinlandCorrespondence to: I. Pörsti 相似文献
129.
Eberhard Schlicker Walter Schunack Manfred Göthert 《Naunyn-Schmiedeberg's archives of pharmacology》1990,342(5):497-501
Summary Discs of pig retina were preincubated with 3H-noradrenaline, 3H-dopamine or 3H-serotonin and then superfused. Electrical field stimulation increased the outflow of tritium from discs preincubated with 3H-noradrenaline or 3H-dopamine, but no from discs preincubated with 3H-serotonin. The tritium content at the end of superfusion was similar in discs preincubated with 3H-noradrenaline or 3H-dopamine but about tenfold lower in discs preincubated with 3H-serotonin. The tritium content in discs preincubated with 3H-noradrenaline was markedly reduced when desipramine was present during preincubation but was not affected by selective inhibitors of dopamine and serotonin uptake. The tritium content in discs preincubated with 3Hdopamine and 3H-serotonin, in contrast, was reduced or tended to be reduced by a selective dopamine and serotonin uptake inhibitor, respectively.The electrically evoked overflow of tritium from discs preincubated with 3H-noradrenaline was abolished by tetrodotoxin or omission of Ca2+. In discs superfused with desipramine, the electrically evoked overflow was enhanced by phentolamine but not affected by histamine. When both desipramine and phentolamine were present in the superfusion medium, histamine inhibited the evoked overflow (pIC15 6.85). This effect was mimicked by the histamine H3 receptor agonist R-(–)--methylhistamine as well as by its S-(+)-enantiomer (pIC15 7.85 and 5.30, respectively) but not by the H1 receptor agonist 2-(2-thiazolyl)ethylamine and the H2 receptor agonist dimaprit (each 10 mol/l). The inhibitory effect of histamine was abolished by the H3 receptor antagonist thioperamide 0.32 mol/l and attenuated by impromidine 3.2 mol/l but not affected by the H1 receptor antagonist dimetindene 3.2 mol/l and the H2 receptor antagonist ranitidine 10 mol/l.The results suggest that, in the pig retina, noradrenaline is taken up into, and released from, noradrenergic neurones (most likely vascular postganglionic sympathetic nerve fibres, less probably tissue-specific noradrenergic neurones of the retina) and that noradrenaline release is subject to modulation via H3 receptors and probably also a-adrenoceptors.Send offprint requests to E. Schlicker at the above address 相似文献
130.
Schulz R Girard C Harrison S 《The International journal of health planning and management》1990,5(2):135-146
Performance priorities for high quality care, multiprofessional team care and deinstitutionalization of patients among mental health services in England and West Germany were found to be significantly influenced by management practices fostering goal congruence, peer review and staff participation in decision making. 相似文献