全文获取类型
收费全文 | 3389篇 |
免费 | 245篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 105篇 |
妇产科学 | 76篇 |
基础医学 | 543篇 |
口腔科学 | 68篇 |
临床医学 | 353篇 |
内科学 | 697篇 |
皮肤病学 | 136篇 |
神经病学 | 425篇 |
特种医学 | 82篇 |
外科学 | 273篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 278篇 |
眼科学 | 46篇 |
药学 | 237篇 |
中国医学 | 5篇 |
肿瘤学 | 267篇 |
出版年
2024年 | 8篇 |
2023年 | 67篇 |
2022年 | 110篇 |
2021年 | 185篇 |
2020年 | 102篇 |
2019年 | 149篇 |
2018年 | 137篇 |
2017年 | 99篇 |
2016年 | 108篇 |
2015年 | 134篇 |
2014年 | 160篇 |
2013年 | 170篇 |
2012年 | 289篇 |
2011年 | 284篇 |
2010年 | 145篇 |
2009年 | 129篇 |
2008年 | 189篇 |
2007年 | 170篇 |
2006年 | 152篇 |
2005年 | 180篇 |
2004年 | 119篇 |
2003年 | 147篇 |
2002年 | 113篇 |
2001年 | 44篇 |
2000年 | 30篇 |
1999年 | 26篇 |
1998年 | 18篇 |
1997年 | 20篇 |
1996年 | 19篇 |
1995年 | 14篇 |
1994年 | 20篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1971年 | 2篇 |
1931年 | 2篇 |
1930年 | 2篇 |
1929年 | 5篇 |
1903年 | 1篇 |
排序方式: 共有3645条查询结果,搜索用时 15 毫秒
101.
Seminotti B da Rosa MS Fernandes CG Amaral AU Braga LM Leipnitz G de Souza DO Woontner M Koeller DM Goodman S Wajner M 《Molecular genetics and metabolism》2012,106(1):31-38
In the present work we evaluated a variety of indicators of oxidative stress in distinct brain regions (striatum, cerebral cortex and hippocampus), the liver, and heart of 30-day-old glutaryl-CoA dehydrogenase deficient (Gcdh(-/-)) mice. The parameters evaluated included thiobarbituric acid-reactive substances (TBA-RS), 2-7-dihydrodichlorofluorescein (DCFH) oxidation, sulfhydryl content, and reduced glutathione (GSH) concentrations. We also measured the activities of the antioxidant enzymes glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), superoxide dismutase (SOD) and glucose-6-phosphate dehydrogenase (G6PD). Under basal conditions glutaric (GA) and 3-OH-glutaric (3OHGA) acids were elevated in all tissues of the Gcdh(-/-) mice, but were essentially absent in WT animals. In contrast there were no differences between WT and Gcdh(-/-) mice in any of the indicators or oxidative stress under basal conditions. Following a single intra-peritoneal (IP) injection of lysine (Lys) there was a moderate increase of brain GA concentration in Gcdh(-/-) mice, but no change in WT. Lys injection had no effect on brain 3OHGA in either WT or Gcdh(-/-) mice. The levels of GA and 3OHGA were approximately 40% higher in striatum compared to cerebral cortex in Lys-treated mice. In the striatum, Lys administration provoked a marked increase of lipid peroxidation, DCFH oxidation, SOD and GR activities, as well as significant reductions of GSH levels and GPx activity, with no alteration of sulfhydryl content, CAT and G6PD activities. There was also evidence of increased lipid peroxidation and SOD activity in the cerebral cortex, along with a decrease of GSH levels, but to a lesser extent than in the striatum. In the hippocampus only mild increases of SOD activity and DCFH oxidation were observed. In contrast, Lys injection had no effect on any of the parameters of oxidative stress in the liver or heart of Gcdh(-/-) or WT animals. These results indicate that in Gcdh(-/-) mice cerebral tissue, particularly the striatum, is at greater risk for oxidative stress than peripheral tissues following Lys administration. 相似文献
102.
Hanifi-Moghaddam P Boers-Sijmons B Klaassens AH van Wijk FH Van Ijcken WF Van der Spek P Verheul HA Kloosterboer HJ Burger CW Blok LJ 《Human reproduction (Oxford, England)》2008,23(2):298-305
BACKGROUND: Combined hormone treatments in post-menopausal women have different clinical responses on uterus and vagina; therefore, we investigated differences in steroid signalling between various hormone therapies in these tissues. METHODS: A total of 30 post-menopausal women scheduled for hysterectomy were distributed into four subgroups: control-group (n = 9), Tibolone-group (n = 8); estradiol (E(2))-group (n = 7); E(2) + medroxyprogesterone acetate (MPA)-group (n = 6). Medication was administered orally every day for 21 days prior to removal of uterus and upper part of the vagina. Tissue RNA was isolated, and gene expression profiles were generated using GeneChip technology and analysed by cluster analysis and significance analysis of microarrays. Apoptosis and cell proliferation assays, as well as immunohistochemistry for hormone receptors were performed. RESULTS: 21-days of treatment with E(2), E(2) + MPA or tibolone imposes clear differential gene expression profiles on endometrium and myometrium. Treatment with E(2) only results in the most pronounced effect on gene expression (up to 1493 genes differentially expressed), proliferation and apoptosis. Tibolone, potentially metabolized to both estrogenic and progestagenic metabolites, shows some resemblance to E(2) signalling in the endometrium and, in contrast, shows significant resemblance to E(2) + MPA signalling in the myometrium. In the vagina the situation is entirely different; all three hormonal treatments result in regulation of a small number (4-73) of genes, in comparison to signalling in endometrium and myometrium. CONCLUSION: Endometrium and myometrium differentially respond to the hormone therapies and use completely different sets of genes to regulate similar biological processes, while in this experiment the upper part of the vagina is hardly hormone responsive. 相似文献
103.
Oral sensitization with shrimp tropomyosin induces in mice allergen-specific IgE, T cell response and systemic anaphylactic reactions 总被引:1,自引:0,他引:1
Capobianco F Butteroni C Barletta B Corinti S Afferni C Tinghino R Boirivant M Di Felice G 《International immunology》2008,20(8):1077-1086
Appropriate murine models of shrimp tropomyosin (ST) allergy would be useful in investigating the mechanisms underlying food allergy in human subjects, as well as for the pre-clinical evaluation of efficacy and safety of novel therapeutic approaches. These models should mimic immune and clinical features of human disease, including anaphylactic response. We sensitized C3H/HeJ mice by the oral route with purified ST using cholera toxin (CT) as adjuvant. ST-specific IgE, IgG1, IgG2a and IgA responses were evaluated by ELISA. Spleen cell proliferation and cytokine production by allergen-specific activation were assessed. Jejunum and colon fragments were collected to evaluate the local expression of cytokine genes by PCR. Local and systemic anaphylactic reactions induced by oral ST challenge were scored according to symptoms observed. Faecal samples were collected to assess local IgA production and histamine levels. Oral sensitization with ST plus CT induced in mice significant levels of serum IgE and IgG1 and faecal IgA. ST-specific cell proliferation and IL-4, IL-13 and IFN-gamma cytokine production were induced in the spleen. After oral challenge, 100% of mice had anaphylactic symptoms while no symptoms were observed in challenged naive mice. Faecal histamine content after ST challenge appeared significantly increased in sensitized mice when compared with that observed in pre-immune mice. Jejunum mRNA expression of T(h)2 cytokines was up-regulated by ST sensitization. These results support the importance of the oral way of sensitization and of the in-depth characterization of the anaphylactic response for the development of a suitable in vivo model of food allergy. 相似文献
104.
De Carolis E Posteraro B Florio AR Colonna B Prosseda G Bugli F Lorenzetti SR Fiscarelli E Inzitari R Iavarone F Castagnola M Fadda G Sanguinetti M 《International journal of medical microbiology : IJMM》2011,301(4):273-281
Stenotrophomonas maltophilia is a microorganism of environmental and clinical importance as well as a frequent airway colonizer of cystic fibrosis (CF) individuals. We combined 2-DE and MALDI-TOF MS to profile the protein expression in S. maltophilia K279a, a completely sequenced clinical isolate, grown at 37 °C with respect to the strain grown at 26 °C. Among the proteins up-regulated at 37 °C, we identified GroEL, a molecular chaperone that mainly assist the folding and unfolding of proteins under both normal and stress conditions. A 2.4-kb groESL mRNA was detected independently by Northern blot analyses with a groES- and a groEL-specific probe, indicating that S. maltophilia groES and groEL form an operon. Primer extension analysis of S. maltophilia groESL done in Escherichia coli showed that 2 promoters, Pσ(32) and Pσ(70), were utilized under the heat-shock and normal condition, respectively, whereas S. maltophilia groEL was shown to act as a heat-shock gene at 37 °C, 42 °C, and, to a lesser extent, at 50 °C by real-time RT-PCR analyses. Finally, immunoblot analyses revealed that S. maltophilia GroEL strongly reacted with sera from CF patients chronically infected by the microorganism, but did not with sera from CF patients with sporadic infection or uninfected. 相似文献
105.
106.
Rodrigo da Costa Carneiro Bianca Grassi de Miranda Carlos Camilo Neto Marina K. Tsukumo Cibele L.C. Fonseca João Silva de Mendonça 《The Brazilian journal of infectious diseases》2010,14(1):77-80
We present two cases of juvenile form of paracoccidioidomycosis (PCM), a systemic mycosis frequently found in rural areas, whose prognosis is poor in children and young adults. They are a 14-year-old boy and a 25-year-old woman, both residents in an urban area in São Paulo – Brazil, without any history of travelling to an endemic area. They have been admitted to the hospital due to fever, weight loss and lymphadenopathy. The diagnosis was confirmed by serologic and histopathologic study. Patients have recovered after therapy with oral itraconazole and were discharged from hospital, maintaining outpatient visits. In this article, the authors discuss the unusual presentation of PCM in an urban area. 相似文献
107.
Sandra Pereson Hans Wils Gernot Kleinberger Eileen McGowan Mado Vandewoestyne Bianca Van Broeck Geert Joris Ivy Cuijt Dieter Deforce Michael Hutton Christine Van Broeckhoven Professor Samir Kumar‐Singh 《The Journal of pathology》2009,219(2):173-181
Amyloid‐β (Aβ) plaques are pathological hallmarks of Alzheimer disease (AD). In addition, innate inflammatory responses, such as those mediated by microglia, are integral to the pathogenesis of AD. Interestingly, only dense‐core plaques and not diffuse plaques are associated with neuritic and inflammatory pathology in AD patients as well as in mouse AD models. However, the precise neuropathological changes that occur in the brain in response to amyloid deposition are largely unknown. To study the molecular mechanism(s) responsible for Aβ‐mediated neuropathology, we performed a gene expression analysis on laser‐microdissected brain tissue of Tg2576 and APPPS1 mice that are characterized by different types of amyloid plaques and genetic backgrounds. Data were validated by image and biochemical analyses on different ages of Tg2576, APPPS1, and Aβ42‐depositing BRI‐Aβ42 mice. Consistent with an important role of inflammatory responses in AD, we identified progranulin (mouse Grn; human GRN) as one of the top ten up‐regulated molecules in Tg2576 (≈8‐fold increased) and APPPS1 (≈2‐fold increased) mice compared to littermate controls, and among the eight significantly up‐regulated molecules common to both mouse models. In addition, Grn levels correlated significantly with amyloid load, especially the dense‐core plaque pathology (p < 0.001). We further showed that Grn is up‐regulated in microglia and neurons and neurites around dense‐core plaques, but not in astrocytes or oligodendrocytes, as has been shown in AD patients. Our data therefore support the ongoing use of these mouse models in drug trials, especially those with anti‐inflammatory compounds. Moreover, the correlation of Grn with increasing disease severity in AD mouse models prompts human studies exploring the viability of GRN as a disease biomarker. Because loss of GRN has recently been shown to cause frontotemporal dementia and serves as a risk factor for AD, the strong GRN reactivity around dense‐core plaques is consistent with an important role of this factor in AD pathogenesis. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
108.
Rima E. Rudd Danielle C. Blanch Victoria Gall Lori B. Chibnik Elizabeth A. Wright William Reichmann Matthew H. Liang Jeffrey N. Katz 《Patient education and counseling》2009
Objective
Test the efficacy of educational interventions to reduce literacy barriers and enhance health outcomes among patients with inflammatory arthritis.Methods
The intervention consisted of plain language information materials and/or two individualized sessions with an arthritis educator. Randomization was stratified by education level. Principal outcomes included adherence to treatments, self-efficacy, satisfaction with care, and appointment keeping. Secondary outcomes included health status and mental health. Data were collected at baseline, six, and twelve months post.Results
Of the 127 patients, half had education beyond high school and three quarters had disease duration greater than five years. There were no differences in the primary outcome measures between the groups. In mixed models controlling for baseline score and demographic factors, the intervention group showed improvement in mental health score at six and twelve months (3.0 and 3.7 points, respectively), while the control group showed diminished scores (−4.5 and −2.6 points, respectively) (p = 0.03 and 0.01).Conclusion
While the intervention appears to have had no effect on primary outcomes, further studies with continued attention to literacy are warranted. Study site and disease duration must be considered as participants in this study had higher than average health literacy and had established diagnoses for years prior to this study.Practice implications
The study offers insight into an application of many of the protocols currently recommended to ameliorate effects of limited literacy. 相似文献109.
Zohara Sternberg Kailash Chadha Alicia Lieberman Allison Drake David Hojnacki Bianca Weinstock-Guttman Frederick Munschauer 《Journal of neuroinflammation》2009,6(1):28-8
The study is aimed to determine the role of luteolin (3',4',5,7-tetrahydroxyflavone), alone and in combination with human
interferon-beta (IFN-β), in modulating the immune response(s) of peripheral blood mononuclear cells (PBMCs) isolated from
multiple sclerosis (MS) patients. PBMC proliferation in the presence or absence of these drugs was determined and the production
of pro-inflammatory cytokines (IL-1β, TNF-α), and the ratio of cell migration mediator MMP-9, and its inhibitor, TIMP-1 was
assessed in the culture supernatants. Luteolin reduced, in a dose-dependent manner, the proliferation of PBMCs, and modulated
the levels of IL-1β and TNF-α released by PBMCs in the culture supernatants. Luteolin reduced the MMP-9/TIMP-1 ratio via lowering
MMP-9 production. In the majority of cases, luteolin, when combined with IFN-β, had additive effects in modulating cell proliferation,
IL-1β, TNF-α, MMP-9 and TIMP-1. 相似文献
110.