全文获取类型
收费全文 | 7329篇 |
免费 | 413篇 |
国内免费 | 55篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 118篇 |
妇产科学 | 85篇 |
基础医学 | 1384篇 |
口腔科学 | 96篇 |
临床医学 | 643篇 |
内科学 | 1181篇 |
皮肤病学 | 164篇 |
神经病学 | 916篇 |
特种医学 | 248篇 |
外科学 | 951篇 |
综合类 | 43篇 |
一般理论 | 2篇 |
预防医学 | 360篇 |
眼科学 | 241篇 |
药学 | 665篇 |
中国医学 | 10篇 |
肿瘤学 | 647篇 |
出版年
2023年 | 24篇 |
2022年 | 58篇 |
2021年 | 100篇 |
2020年 | 51篇 |
2019年 | 88篇 |
2018年 | 84篇 |
2017年 | 62篇 |
2016年 | 90篇 |
2015年 | 133篇 |
2014年 | 158篇 |
2013年 | 273篇 |
2012年 | 390篇 |
2011年 | 428篇 |
2010年 | 277篇 |
2009年 | 259篇 |
2008年 | 457篇 |
2007年 | 532篇 |
2006年 | 495篇 |
2005年 | 570篇 |
2004年 | 480篇 |
2003年 | 528篇 |
2002年 | 486篇 |
2001年 | 90篇 |
2000年 | 69篇 |
1999年 | 98篇 |
1998年 | 137篇 |
1997年 | 95篇 |
1996年 | 86篇 |
1995年 | 68篇 |
1994年 | 65篇 |
1993年 | 76篇 |
1992年 | 40篇 |
1991年 | 67篇 |
1990年 | 41篇 |
1989年 | 47篇 |
1988年 | 33篇 |
1987年 | 28篇 |
1986年 | 33篇 |
1985年 | 25篇 |
1984年 | 31篇 |
1983年 | 29篇 |
1982年 | 35篇 |
1981年 | 37篇 |
1980年 | 31篇 |
1979年 | 22篇 |
1978年 | 23篇 |
1977年 | 35篇 |
1976年 | 25篇 |
1974年 | 33篇 |
1973年 | 24篇 |
排序方式: 共有7797条查询结果,搜索用时 0 毫秒
61.
62.
Hanno Niess Nikolaus Börner Maximilian Muenchhoff Elham Khatamzas Manfred Stangl Alex Graf Philipp Girl Enrico Georgi Dionysios Koliogiannis Gerald Denk Michael Irlbeck Jens Werner Markus Guba 《American journal of transplantation》2021,21(4):1629-1632
To date, little is known about the duration and effectiveness of immunity as well as possible adverse late effects after an infection with SARS-CoV-2. Thus it is unclear, when and if liver transplantation can be safely offered to patients who suffered from COVID-19. Here, we report on a successful liver transplantation shortly after convalescence from COVID-19 with subsequent partial seroreversion as well as recurrence and prolonged shedding of viral RNA. 相似文献
63.
Anne Marie Thow Raphael A Lencucha Kieron Rooney Stephen Colagiuri Manfred Lenzen 《Bulletin of the World Health Organization》2021,99(1):41
ObjectiveTo estimate the impact of reduced consumption of free sugars in line with World Health Organization recommendations, on sugar farmers globally.MethodsUsing multiregion input–output analysis, we estimated the proportional impact on production volumes of a 1% reduction in free sugars consumption by the public. We extracted data on sugar production from the Food and Agriculture Organization of the United Nations database for the top 15 sugar-cane- and beet-producing countries globally, and created a custom multiregion input–output database to assess the proportions of production going to human consumption, drawing on household expenditure surveys and national input–output databases (data valid for years 2000–2015). We also considered the impact on production volumes in relation to countries’ gross domestic product.FindingsA high proportion of current sugar production from these countries goes to human consumption, and would thus be impacted by reduced consumption of sugars. The largest impacts on cane sugar production, and thus on farmers, would likely occur in Brazil, China, India and Thailand and on beet production in Belarus, Germany, Russian Federation and United States of America.ConclusionA global opportunity exists for public health leadership to bring together the health, economic, environmental and agriculture sectors to collaborate and build capacity for promotion of alternative livelihoods for sugar farmers. Lessons regarding strategy and the importance of political economy factors can be learnt from tobacco control measures. Further research to quantify the impact of reductions in sugars consumption would provide useful insights for designing policies to complement and strengthen efforts to improve diets and health. 相似文献
64.
65.
Bibek Dutta Taichi Asami Tohru Imatomi Kento Igarashi Kento Nagata Tomomi Watanabe-Asaka Takako Yasuda Shoji Oda Manfred Shartl Hiroshi Mitani 《Journal of radiation research》2021,62(1):12
Transgenic expression in medaka of the Xiphophorus oncogene xmrk, under a pigment cell specific mitf promoter, induces hyperpigmentation and pigment cell tumors. In this study, we crossed the Hd-rR and HNI inbred strains because complete genome information is readily available for molecular and genetic analysis. We prepared an Hd-rR (p53+/−, p53−/−) and Hd-rR HNI hybrid (p53+/−) fish-based xmrk model system to study the progression of pigment cells from hyperpigmentation to malignant tumors on different genetic backgrounds. In all strains examined, most of the initial hyperpigmentation occurred in the posterior region. On the Hd-rR background, mitf:xmrk-induced tumorigenesis was less frequent in p53+/− fish than in p53−/− fish. The incidence of hyperpigmentation was more frequent in Hd-rR/HNI hybrids than in Hd-rR homozygotes; however, the frequency of malignant tumors was low, which suggested the presence of a tumor suppressor in HNI genetic background fish. The effects on tumorigenesis in xmrk-transgenic immature medaka of a single 1.3 Gy irradiation was assessed by quantifying tumor progression over 4 consecutive months. The results demonstrate that irradiation has a different level of suppressive effect on the frequency of hyperpigmentation in purebred Hd-rR compared with hybrids. 相似文献
66.
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
67.
Hans Schmid Manfred Kaufmann Eva-Maria Grischke Gunther Bastert 《Cancer chemotherapy and pharmacology》1990,26(Z1):S71-S73
The objective of our clinical studies was to develop an effective combination chemotherapy regimen (CHT) with acceptable side effects, consisting of the two most potent drugs used as single agents in breast cancer. We tested the combination of an anthracycline, epirubicin (A) at 70 mg/m2 i.v. on day 1 or (B) at 120 mg/m2 i.v. on day 1 with an alkylating drug ifosfamide (IFO), (C) at 2.5 g/m2 in an i.v. infusion given over 4 h on days 1–3 or (D) at 5 g/m2 in a 24-h i.v. infusion given on day 1. Courses were repeated every 4 weeks. The combinations were given as first-line therapy as follows: CHT (A, C) in six cases and CHT (B, C) in five cases of advanced breast carcinoma, and CHT (B, D) in seven patients with primary inflammatory breast cancer. Due to side effects (e.g., stomatitis, mental disturbances) and applicability, CHT regimen (B, D) was preferred. Responses (12/18) occurred 1–3 cycles earlier than those previously achieved using the conventional epirubicin/cyclophosphamide CHT. We conclude that 5 g/m2 IFO given i.v. over 24 h with uroprotection (mesna) in a two-drug regimen is an effective dose with tolerable toxicity. Alopecia was seen in all cases. However, according to our experience, myelotoxicity is the dose-limiting factor for both of these drugs.Presented at the Satellite Symposium Ifosfamide in Gynecological Tumors of the 5th European Conference on Clinical Oncology and Cancer Nursing, London, September 3–7, 1989 相似文献
68.
John Halim Günther G. Scherer Manfred Stamm 《Macromolecular chemistry and physics.》1994,195(12):3783-3788
Room temperature recast Nafion 1 General formula: films, prepared under different humidities in the curing atmosphere, were characterized by small- and wide-angle X-ray scattering (SAXS and WAXS). SAXS reveals that the humidity influences the size of the ionic clusters in these polymer films. It was found that the number and size of ionic clusters increases with increasing relative humidity. WAXS indicates the presence of locally ordered regions of the backbone polymer. These results allow a qualitative understanding of the electrochemical behaviour of Nafion recast films cured at different humidities, as described in the literature. 相似文献
69.
70.
Albert J. Augustin Manfred Spitznas Nahid Kaviani Daniel Meller Frank H. J. Koch Franz Grus Martin J. Göbbels 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1995,233(11):694-698
Purpose: To evaluate whether products of oxidative and inflammatory reactions are detectable in the tear fluid of patients suffering from dry eyes. Methods: The tear fluid of 217 patients (397 eyes) was sampled. Criteria for grouping of the patients were (1) basic secretion test (sicca l: BST = 0–5 mm, n = 78 eyes; sicca 2: BST = 6–10 mm, n = 109 eyes) and (2) subjective symptoms (normal BST, burning, foreign body sensations, tearing, dryness of the eyes: n = 78 eyes). One group of healthy patients (normal BST, n = 132 eyes) served as controls. Lipid peroxide levels and myeloperoxidase activity, as parameters for oxidative tissue damage and inflammatory activity, were determined in the tear fluid. Those patients whose consent could be obtained were subjected to the rose bengal test (sicca 1: 56 eyes; sicca 2: 97 eyes; subjective symptoms: 44 eyes; controls: 49 eyes). The correlation between BST and rose bengal test results was calculated. Results: Lipid peroxides were significantly (P < 0.05) higher in the groups sicca 1 and subjective symptoms than in healthy controls, as was the inflammatory activity in groups sicca 1, sicca 2 and subjective symptoms. Additionally, the inflammatory activity in the group sicca 1 was significantly (P < 0.05) higher than in the groups sicca 2 and subjective symptoms. No evidence of a significant correlation between BST and rose bengal test results was observed. Conclusions: Both oxidative tissue damage and polymorphonuclear leukocytes indicating an oxidative potential occur in the tear film of patients suffering from dry eyes. These reactions lead to severe damage of the involved tissue. Free radicals and inflammation may be involved in the pathogenesis or in the self-propagation of the disease. 相似文献