全文获取类型
收费全文 | 22553篇 |
免费 | 1234篇 |
国内免费 | 112篇 |
专业分类
耳鼻咽喉 | 232篇 |
儿科学 | 529篇 |
妇产科学 | 469篇 |
基础医学 | 2958篇 |
口腔科学 | 595篇 |
临床医学 | 1747篇 |
内科学 | 6051篇 |
皮肤病学 | 537篇 |
神经病学 | 2104篇 |
特种医学 | 554篇 |
外科学 | 3426篇 |
综合类 | 108篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 1562篇 |
眼科学 | 443篇 |
药学 | 1122篇 |
中国医学 | 44篇 |
肿瘤学 | 1413篇 |
出版年
2023年 | 176篇 |
2022年 | 375篇 |
2021年 | 824篇 |
2020年 | 371篇 |
2019年 | 728篇 |
2018年 | 833篇 |
2017年 | 483篇 |
2016年 | 503篇 |
2015年 | 581篇 |
2014年 | 795篇 |
2013年 | 1119篇 |
2012年 | 1792篇 |
2011年 | 1698篇 |
2010年 | 987篇 |
2009年 | 920篇 |
2008年 | 1438篇 |
2007年 | 1471篇 |
2006年 | 1413篇 |
2005年 | 1357篇 |
2004年 | 1108篇 |
2003年 | 1076篇 |
2002年 | 1015篇 |
2001年 | 168篇 |
2000年 | 129篇 |
1999年 | 192篇 |
1998年 | 166篇 |
1997年 | 169篇 |
1996年 | 140篇 |
1995年 | 132篇 |
1994年 | 122篇 |
1993年 | 100篇 |
1992年 | 103篇 |
1991年 | 114篇 |
1990年 | 74篇 |
1989年 | 68篇 |
1988年 | 65篇 |
1987年 | 75篇 |
1986年 | 75篇 |
1985年 | 77篇 |
1984年 | 73篇 |
1983年 | 46篇 |
1982年 | 50篇 |
1981年 | 60篇 |
1980年 | 44篇 |
1979年 | 64篇 |
1978年 | 52篇 |
1977年 | 41篇 |
1976年 | 45篇 |
1975年 | 35篇 |
1974年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
71.
Anthony J McGoron Michael Capille Michael F Georgiou Pablo Sanchez Juan Solano Manuel Gonzalez-Brito John W Kuluz 《BMC medical imaging》2008,8(1):4
Background
Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. 相似文献72.
Biochemical and functional alterations induced by CD23 ligation in the human promonocytic cell line U937. 下载免费PDF全文
N Paul-Eugene C Amirand F Ouaaz J P Ballini D M Mossalayi B Dugas J P Kolb 《Immunology》1993,80(3):424-430
The early events triggered in interleukin-4 (IL-4)-stimulated U937 cells by ligation of CD23/Fc epsilon RII with specific monoclonal antibodies (mAb) were analysed, as a model of the action of this molecule on the differentiation of promonocytic cells. As well as IL-4-activated human monocytes, addition of anti-CD23 mAb to IL-4-treated U937 cells triggered cAMP accumulation but did not evoke significant polyphosphoinositide hydrolysis. However, by a microspectrofluorometric technique allowing single cell analysis, anti-CD23 mAb was found to elicit calcium mobilization in these cells. In addition, the treatment induced phenotypic alterations in these cells, as evidenced by the acquisition of the monocyte marker CD14 and the increase of the alpha-chain (CD11a) and of the common beta-chain (CD18) of the leucocyte function-associated antigen 1 (LFA-1) family antigens. Although weaker than in monocytes, CD23 ligation evoked a small secretion of the pro-inflammatory mediators IL-6 and thromboxane B2. These data suggest that a significant maturation of promonocytic cells towards a more mature monocytic phenotype can be achieved through successive exposure to IL-4 and CD23 ligation. 相似文献
73.
There is some evidence that, in asthma, mast cells infiltrate the airway smooth muscle layer and, as a consequence, alter the functional and structural properties of myocytes. This inflammation so-called mast-cell myositis, probably contributes to both bronchial hyperresponsiveness and airway remodelling. Previous observations have pointed out the presence of mast cells within airway smooth muscle of atopic patients and recent data obtained in asthmatic patients demonstrate that this infiltration is more important in asthmatic patients with atopy. Although the mechanism of such a mast cell attraction remains to be fully understood, experimental data demonstrate that, upon stimulation by tryptase or cytokines, smooth muscle cells can attract mast cells through the production of TGF-beta1 or SCF. Once at the site of inflammation, activated mast cells are responsible for an important extracellular deposition of inflammatory products that may facilitate the increase in smooth muscle mass. In addition, comparison of asthmatic patients with and without atopy suggests that mast cell myositis is closely related with atopy. 相似文献
74.
Sauseng P Klimesch W Doppelmayr M Hanslmayr S Schabus M Gruber WR 《Neuroscience letters》2004,354(2):123-126
The role of coupling between prefrontal and temporo-parietal brain areas within the theta frequency range of the human electroencephalogram was explored in a working memory task. During encoding of visual information higher theta amplitudes were observed in the right compared to the left hemisphere. Retrieval of visuospatial and verbal information elicited a more bilateral activation pattern. These effects were accompanied by theta coupling between dorsolateral prefrontal and right posterior temporal electrode sites during encoding. During retrieval prefrontal and bilateral temporo-parietal brain areas were coupled. These results support the idea of working memory functions being dependent on distributed prefrontal-temporal networks. 相似文献
75.
Evaluation of the COBAS TaqMan 48 real-time PCR system for quantitation of hepatitis B virus DNA 总被引:5,自引:0,他引:5 下载免费PDF全文
The purpose of this study is to evaluate the usefulness of the new real-time PCR COBAS TaqMan 48 analyzer, comparing it to the existing COBAS AMPLICOR HBV MONITOR based on conventional PCR technology. The study used 104 samples from different patients. No differences were found in the sensitivity of the tests. There was an excellent correlation between the sample with a viral load within the dynamic range of the two tests (r = 0.938). The COBAS TaqMan test has a wider linear range, and this fact enables quantifying of the viral load without diluting the sample. 相似文献
76.
Electroconvulsive therapy (ECT) is an effective and safe treatment for depression. Anticoagulation therapy is used to reduce morbidity or mortality from stroke or recurrent pulmonary embolus in various cardiac and vascular conditions. We report in detail the successful ECT treatment of a patient suffering from major depression with psychotic features who continued warfarin (Coumadin) anticoagulant therapy. 相似文献
77.
Ocasio Manuel A. Lozano Alyssa Lee Tae Kyoung Feaster Daniel J. Carrico Adam Prado Guillermo 《Prevention science》2022,23(1):119-129
Prevention Science - Despite the availability of efficacious and effective family-based interventions, such interventions are scarce for sexual minority adolescents, particularly among... 相似文献
78.
Marlene Fabiola Escobedo-Monge María Carmen Torres-Hinojal Enrique Barrado María Antonieta Escobedo-Monge Jos Manuel Marugn-Miguelsanz 《Nutrients》2021,13(4)
Background: Zinc is an essential trace element for the normal growth and development of human beings. The main objective was to evaluate the nutritional status of zinc and its association with nutritional indicators in a series of children with chronic diseases. Methods: The prevalence of patients with dietary zinc deficiency or deficit zinc intake (<80% DRI: dietary reference intake) was analyzed through prospective 72 h dietary surveys, and serum zinc deficiency or hypozincemia (≤70 µg/dL in children under 10 years of age in both sexes and in females older than 10 years and <74 μg/dL in males older than 10 years) was measured through atomic absorption spectrophotometry. The participants were classified according to their nutritional status by body mass index (BMI). Results: Mean serum zinc level in obese (87 µg/dL), undernourished (85 µg/dL), and eutrophic children (88 µg/dL) were normal, but in the undernutrition (60% DRI) and eutrophic (67% DRI) groups the mean dietary zinc intake was low compared to that in the obesity group (81% DRI). There were different associations between nutritional parameters, dietary zinc intake, and serum zinc. All patients with hypozincemia had dietary zinc deficiency. Conclusions: In the whole series, 69% of participants showed a zinc intake lower than recommended and might be at high risk of zinc deficiency. 相似文献
79.
Brenes Monge Alexander Fernández Elorriaga María Poblano Verástegui Ofelia Valdez Santiago Rosario Martínez Nolasco Manuel A. Yáñez Álvarez Iraís Saturno Hernández Pedro J. 《Maternal and child health journal》2021,25(4):565-573
Maternal and Child Health Journal - To identify and describe the frequency and characteristics of disrespect and abuse practices towards women during facility-based delivery in four hospitals in... 相似文献
80.