全文获取类型
收费全文 | 5316篇 |
免费 | 206篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 157篇 |
儿科学 | 75篇 |
妇产科学 | 259篇 |
基础医学 | 646篇 |
口腔科学 | 49篇 |
临床医学 | 454篇 |
内科学 | 1604篇 |
皮肤病学 | 49篇 |
神经病学 | 443篇 |
特种医学 | 92篇 |
外科学 | 628篇 |
综合类 | 33篇 |
一般理论 | 1篇 |
预防医学 | 180篇 |
眼科学 | 72篇 |
药学 | 405篇 |
中国医学 | 4篇 |
肿瘤学 | 404篇 |
出版年
2024年 | 13篇 |
2023年 | 42篇 |
2022年 | 243篇 |
2021年 | 363篇 |
2020年 | 87篇 |
2019年 | 129篇 |
2018年 | 147篇 |
2017年 | 110篇 |
2016年 | 128篇 |
2015年 | 163篇 |
2014年 | 209篇 |
2013年 | 284篇 |
2012年 | 405篇 |
2011年 | 419篇 |
2010年 | 205篇 |
2009年 | 142篇 |
2008年 | 346篇 |
2007年 | 378篇 |
2006年 | 328篇 |
2005年 | 308篇 |
2004年 | 330篇 |
2003年 | 304篇 |
2002年 | 217篇 |
2001年 | 18篇 |
2000年 | 19篇 |
1999年 | 23篇 |
1998年 | 25篇 |
1997年 | 14篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 13篇 |
1993年 | 8篇 |
1992年 | 12篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 16篇 |
1985年 | 6篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1971年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有5555条查询结果,搜索用时 15 毫秒
81.
Primary cutaneous T-cell lymphomas (CTCL) represent a heterogeneous group of neoplasms derived from skin-homing T cells. CTCL
behave similarly to indolent B-cell lymphomas. There is increasing evidence that angiogenesis may be important in lymphoproliferative
disorders. The aim of the study was to evaluate microvessel density (MVD) as a parameter of tumor angiogenesis measured by
the expression of CD34 in the skin samples in CTCL patients. Formaldehyde-fixed, paraffin-embedded skin tumor biopsy specimens
from 25 patients (16 men, 9 women) with CTCL (mycosis fungoides), and 8 skin samples from healthy volunteers were analysed.
The preparations were stained with haematoxylin and eosin, and evaluated histopathologically. Staining for endothelial cells
with monoclonal antibody against CD34 revealed a mean number of 134 dots per mm2 for CTCL and 106 dots/mm2 for controls; the difference was statistically significant (p=0.0388). Our study shows a higher number of microvessels in
primary CTCL compared with normal skin. Microvascular endothelial cells have become an important target in cancer therapy.
Increased MVD in the skin of CTCL patients indicate that angiogenesis may play a role in the growth of CTCL, and raises the
possibility of using angiogenesis inhibitors in CTCL therapy. 相似文献
82.
83.
Brudek T Christensen T Hansen HJ Bobecka J Møller-Larsen A 《AIDS research and human retroviruses》2004,20(4):415-423
Retroviruses have been suggested as possible pathogenic factors in multiple sclerosis (MS), supported by the observation that endogenous retroviruses are activated in MS patients. Different members of the herpes family of which several are neurotropic have also been suggested as factors in MS pathogenesis. Further, interactions between retroviruses and herpes viruses have been implied in the development of MS. The objective of the study was investigation of cell-mediated immune responses of MS patients to retrovirus and herpes virus antigens, particularly antigen combinations, with analyses of the influence of retrovirus antigens on cellular immunological reactivity toward other viral antigens. Cellular immunity as measured by blast transformation assays was analyzed using freshly isolated peripheral blood mononuclear cells from 47 MS patients and 36 healthy volunteers. Combinations of the endogenous retrovirus HERV-H and herpes virus antigens resulted in highly increased cellular immune responses among both the MS patients and healthy subjects. The increase was synergistic in character in most samples. Very pronounced effects were obtained using HHV-6A and HSV-1 antigens. Blast transformation assays combining antigens from two different herpes viruses or combinations of measles and herpes antigens showed no synergy. The obtained data indicate a pronounced synergistic effect on the cellular immune response when retrovirus and herpes antigens are present together. The cause of the synergy is unknown so far. The effect on the immune response may influence the disease progression. 相似文献
84.
Snopek G Bruszewska E Rywik T Sobieszczańska-Małek M 《International journal of cardiology》2004,93(2-3):309-310
We present the case of a 36-year-old female with severe heart failure which developed 20 years after irradiation due to Hodgkin's disease. 相似文献
85.
86.
Brzozowski T Konturek PC Moran AP Pajdo R Kwiecien S Konturek SJ Sliwowski Z Drozdowicz D Pawlik WW Hahn EG 《The Journal of pharmacology and experimental therapeutics》2004,310(1):116-125
Lipopolysaccharide (LPS) is one of the virulence factors in the Helicobacter pylori (Hp)-infected stomach, but it remains unknown whether single and prolonged pretreatment with Hp-LPS can affect the course of gastric damage induced by aspirin (ASA). We compared the effects of Hp-LPS with those induced by LPSs isolated from intestinal Bacteroides fragilis, Yersinia enterocolitica, and Campylobacter jejuni applied for 4 days on acute ASA-induced gastric lesions in rats. The area of ASA-induced gastric lesions, gastric blood flow (GBF), expression of mRNA and protein of leptin and plasma leptin, gastrin, interleukin-1beta, and tumor necrosis factor-alpha levels were examined. Single (once) or repeated (five times) i.p. injections of Hp-LPS (1 mg/kg) or intestinal LPSs failed to produce macroscopic gastric damage and did not affect the GBF when compared with vehicle. Hp-LPS injected repeatedly suppressed the gastric acid secretion, up-regulated leptin mRNA and protein, and increased plasma leptin and gastrin levels. Hp-LPS significantly reduced the ASA-induced gastric damage and the accompanying decline in the GBF, and these effects were significantly attenuated by capsaicin denervation and selective antagonism of cholecystokinin-B (CCK2) receptors by RPR-102681 [N-(metoxy-3 phenyl) N-(N-methyl N-phenyl-carbamylmethyl) carbamoylmethyl]-3 ureido]-3 phenyl]-2 propronique] but not by loxiglumide, an antagonist of CCK1 receptors. We conclude that 1) daily application of Hp-LPS enhances gastric mucosal resistance against ASA damage due to the increase of GBF and the expression and release of leptin and gastrin exerting trophic and gastroprotective effects, and 2) this enhanced resistance to ASA damage in Hp-LPS-adapted stomach is mediated by the sensory afferents and specific CCK2/gastrin receptors. 相似文献
87.
A prospective, multicenter, open-label assessment of atomoxetine in non-North American children and adolescents with ADHD 总被引:1,自引:0,他引:1
Buitelaar JK Danckaerts M Gillberg C Zuddas A Becker K Bouvard M Fagan J Gadoros J Harpin V Hazell P Johnson M Lerman-Sagie T Soutullo CA Wolanczyk T Zeiner P Fouche DS Krikke-Workel J Zhang S Michelson D;Stomoxetine International Study Group 《European child & adolescent psychiatry》2004,13(4):249-257
OBJECTIVE: The aim of this study was to study treatment response to atomoxetine in a large, multicenter study of non-North American patients with ADHD. METHODS: A total of 604 children and adolescents with ADHD were enrolled in a 10-week open-label trial with atomoxetine prior to randomization to a double-blind relapse prevention phase at 33 sites in the United Kingdom, continental Europe, Israel, South Africa, and Australia. All patients had ADHD symptom severity at least 1.5 standard deviations above United States age and gender norms for their diagnostic subtype as measured by the investigator-scored ADHD Rating Scale (ADHD RS). Outcomes were assessed by analysis of change in the ADHD RS; functional and psychosocial outcomes were assessed using the Child Health Questionnaire (CHQ). RESULTS: At endpoint, ADHD RS total scores decreased by an average of 56.7%, and 69% of patients were rated as having no or minimal symptoms. Significant improvement was observed in psychosocial and functional outcomes. Discontinuations attributed to adverse events were < 4%. CONCLUSION: These open-label data, gathered in an international setting, add to our knowledge of the value of atomoxetine in treating ADHD symptoms, as well as its safety and tolerability. 相似文献
88.
89.
1,25-Dihydroxyvitamin D (calcitriol), the most active metabolite of vitamin D, has significant antineoplastic activity in preclinical models. Several mechanisms of activity have been proposed. These include inhibition of proliferation associated with cell cycle arrest and, in some models, differentiation, reduction in invasiveness and angiogenesis, and induction of apoptosis. Proposed mechanisms differ between tumor models and experimental conditions, and no unifying hypothesis about the mechanism of antineoplastic activity has emerged. Synergistic and/or additive effects with cytotoxic chemotherapy, radiation, and other cancer drugs have been reported. Significantly supraphysiological concentrations of calcitriol are required for antineoplastic effects. Such concentrations are not achievable in patients when calcitriol is dosed daily due to predictable hypercalcemia and hypercalcuria; however, phase I trials have demonstrated that intermittent dosing allows substantial dose escalation and has produced potentially therapeutic peak calcitriol concentrations. Recently, a phase II study reported encouraging levels of activity for the combination of high-dose calcitriol and docetaxel administered on a weekly schedule in patients with androgen-independent prostate cancer. This regimen is now under study in a placebo-controlled randomized trial in androgen-independent prostate cancer and in phase II studies in several other tumor types. Further work is needed to elucidate the molecular mechanisms of antineoplastic activity and optimal clinical applications of calcitriol in cancer. 相似文献
90.