首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2744篇
  免费   137篇
  国内免费   23篇
耳鼻咽喉   30篇
儿科学   45篇
妇产科学   49篇
基础医学   354篇
口腔科学   32篇
临床医学   206篇
内科学   760篇
皮肤病学   42篇
神经病学   153篇
特种医学   102篇
外科学   397篇
综合类   16篇
一般理论   1篇
预防医学   81篇
眼科学   101篇
药学   245篇
中国医学   3篇
肿瘤学   287篇
  2024年   2篇
  2023年   29篇
  2022年   57篇
  2021年   93篇
  2020年   41篇
  2019年   70篇
  2018年   85篇
  2017年   54篇
  2016年   85篇
  2015年   86篇
  2014年   94篇
  2013年   126篇
  2012年   218篇
  2011年   206篇
  2010年   137篇
  2009年   98篇
  2008年   170篇
  2007年   202篇
  2006年   209篇
  2005年   178篇
  2004年   144篇
  2003年   161篇
  2002年   144篇
  2001年   26篇
  2000年   24篇
  1999年   24篇
  1998年   27篇
  1997年   16篇
  1996年   20篇
  1995年   9篇
  1994年   11篇
  1993年   8篇
  1992年   8篇
  1991年   13篇
  1990年   5篇
  1989年   3篇
  1988年   2篇
  1987年   4篇
  1986年   1篇
  1985年   3篇
  1984年   2篇
  1982年   1篇
  1981年   3篇
  1978年   2篇
  1974年   1篇
  1972年   1篇
  1964年   1篇
排序方式: 共有2904条查询结果,搜索用时 15 毫秒
41.
42.
43.
Cardiotoxicity is a critical complication of allogeneic hematopoietic cell transplantation (allo-HCT). In particular, management of severe cardiotoxicity occurring in the early phases of allo-HCT is challenging. We encountered a case of severe cardiotoxicity resulting from AHF six days after allo-HCT, which resisted catecholamines and diuretics. The patient was treated with anthracycline-containing regimens and underwent myeloablative conditioning, including high-dose cyclophosphamide. As invasive circulatory assisting devices were contraindicated because of his immunocompromised status and bleeding tendency, we successfully treated the patient with ivabradine-containing medications. Ivabradine may therefore be considered an alternative drug for the treatment of severe cardiotoxicity induced by cytotoxic agents.  相似文献   
44.
45.

Background

The aim of this study was to investigate the efficacy of rikkunshito (RKT), a traditional Japanese medicine, combined with proton pump inhibitor (PPI) in patients with PPI-refractory non-erosive reflux disease (NERD).

Methods

Patients with PPI-refractory NERD (n = 242) were randomly assigned to the RKT group [rabeprazole (10 mg/day) + RKT (7.5 g/t.i.d.) for 8 weeks] or the placebo group (rabeprazole + placebo). After the 4- and 8-week treatments, we assessed symptoms and quality of life (QOL) using the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG), Gastrointestinal Symptom Rating Scale (GSRS), and Short-Form Health Survey-8 (SF-8).

Results

There were no significant differences in FSSG and GSRS score improvement between these groups after the 4- and 8-week treatments. The mental component summary (MCS) scores of the SF-8 improved more in the RKT group (from 45.8 ± 8.1 to 48.5 ± 7.4) than in the placebo group (from 47.7 ± 7.1 to 48.4 ± 7.5) after the 4-week treatment (P < 0.05). The 8-week treatment with RKT was more effective for improvement of the degree of MCS score in patients with a low body mass index (<22) (P < 0.05) and significantly improved the acid-related dysmotility symptoms of FSSG in female and elderly patients (≥65 years).

Conclusion

There were no significant differences in improvement of GERD symptoms in patients with PPI-refractory NERD between these groups. However, RKT may be useful for improving mental QOL in non-obese patients and acid-related dyspeptic symptoms, especially in women and the elderly.  相似文献   
46.
Critical role of CD44 in hepatotoxin-mediated liver injury   总被引:2,自引:0,他引:2  
BACKGROUND/AIMS: Blocking of adhesion molecules is considered to be one of the therapeutic strategies inflammatory diseases, although it remains unclear whether this strategy is beneficial. METHODS: We used CD44-deficient mice to assess whether inhibition of CD44 could control liver injury caused by carbon tetrachloride (CCl(4)). RESULTS: CD44-deficient mice exhibited suppressed liver inflammation during the early phase (within 6h) after CCl(4) injection due to reduced inflammatory cell infiltration and cytokine production, but showed severe liver inflammation with increased numbers of apoptotic hepatocytes at the late phase (after 12h). The induction of hepatocyte apoptosis was triggered by reduced NF-kappaB activity, which was induced by the low inflammatory cytokine concentrations. Furthermore, macrophages contributed to the induction of hepatocyte apoptosis, since neutralization by an anti-CD11b antibody significantly protected against hepatocyte apoptosis. Finally, we found that blocking of MIP-2 and TNF-alpha reduced hepatocyte apoptosis with decreased numbers of intrahepatic leukocytes and reduced inflammatory cytokine production. CONCLUSIONS: These findings suggest that targeting of CD44 as a therapeutic approach for inflammatory liver diseases may require caution for particular immune systems in the liver.  相似文献   
47.
Palmoplantar pustulosis (PPP) is characterized by neutrophilic pustules with erythema, which are limited to the hands and feet. Although granulocyte and monocyte adsorption apheresis (GMA) has shown remarkable effects on generalized pustular psoriasis, there are few reports of PPP treated with GMA. We treated three refractory PPP patients using GMA weekly for 5 weeks. The skin eruptions were assessed by a 5‐grade score for scales, pustules, and erythema. GMA decreased the total grade from 9 to 2 in patients 1 and 2, and from 7 to 3 in patient 3. The GMA effects were estimated to be excellent in all three patients. Pustule formation and pain disappeared in all cases. The treatment effect lasted for at least 5 months after GMA. GMA was also effective for relieving the arthralgia in one patient, but it recurred at 6 weeks. Based on these findings, GMA could be an effective therapy for refractory PPP.  相似文献   
48.
49.
A 60-year-old Japanese woman was diagnosed with celiac disease (CeD) and treated with a gluten-free diet. For five years, she had a good clinical course. However, she complained of inappetence and nausea. Colonoscopy revealed ulcerative tumors in the terminal ileum. A histological examination of biopsy specimens from the ulcerative tumor showed diffuse infiltration of large atypical lymphocytes. Immunohistologically, the atypical lymphoid cells were positive for cluster of differentiation (CD)10 and CD20. Many Epstein-Barr virus-encoded small RNA (EBER)-positive atypical lymphocytes were detected by in situ hybridization. This represents the first reported case of Epstein-Barr virus-positive intestinal diffuse large B-cell lymphoma complicated with CeD.  相似文献   
50.
Mounting evidence suggests that nematode infection can protect against disorders of immune dysregulation. Administration of live parasites or their excretory/secretory (ES) products has shown therapeutic effects across a wide range of animal models for immune disorders, including asthma. Human clinical trials of live parasite ingestion for the treatment of immune disorders have produced promising results, yet concerns persist regarding the ingestion of pathogenic organisms and the immunogenicity of protein components. Despite extensive efforts to define the active components of ES products, no small molecules with immune regulatory activity have been identified from nematodes. Here we show that an evolutionarily conserved family of nematode pheromones called ascarosides strongly modulates the pulmonary immune response and reduces asthma severity in mice. Screening the inhibitory effects of ascarosides produced by animal-parasitic nematodes on the development of asthma in an ovalbumin (OVA) murine model, we found that administration of nanogram quantities of ascr#7 prevented the development of lung eosinophilia, goblet cell metaplasia, and airway hyperreactivity. Ascr#7 suppressed the production of IL-33 from lung epithelial cells and reduced the number of memory-type pathogenic Th2 cells and ILC2s in the lung, both key drivers of the pathology of asthma. Our findings suggest that the mammalian immune system recognizes ascarosides as an evolutionarily conserved molecular signature of parasitic nematodes. The identification of a nematode-produced small molecule underlying the well-documented immunomodulatory effects of ES products may enable the development of treatment strategies for allergic diseases.

Parasitic nematodes are associated with almost all groups of vertebrates, and nearly one-third of the human population is infected with these helminths (1). Their omnipresence is in part due to their ability to modulate host immune responses to prevent immune attack and expulsion (2). The elimination of nematode infections has been proposed as a possible cause of the increased incidence of autoimmune disorders and allergic diseases in developed countries (3), based on epidemiological data showing a correlation between the decline in helminth infection and the rise in allergic and autoimmune diseases, including asthma, multiple sclerosis (MS), type 1 diabetes, and inflammatory bowel diseases (IBDs) (4).The administration of live nematodes or their excretory/secretory (ES) products has shown therapeutic effects across a wide range of animal models for these immune disorders (58). The US Food and Drug Administration recently approved live helminth administration as an investigational drug for the treatment of immune disorders, and relevant human clinical trials are ongoing (9). Despite mounting evidence that helminths have significant therapeutic potential, we do not yet have a comprehensive understanding of the molecules that underlie their immunomodulatory effects; and, in particular, the possible relevance of low-molecular-weight components of ES products has remained largely unexplored.A wide range of nematodes, including many parasitic species, produce ascarosides, a family of small-molecule signals based on glycosides of the dideoxysugar ascarylose (10). Ascarosides have not yet been identified in any other animal phylum, suggesting that they may be a nematode-specific class of small molecules (SI Appendix, Fig. S1A). The first ascaroside-based signaling molecules were identified in the free-living model nematode Caenorhabditis elegans (11, 12). Ascarosides regulate almost every aspect of C. elegans life history, including diapause (dauer) induction, aging, mate finding, and aggregation (11, 12). Subsequently, ascarosides have been shown to be detected by organisms other than nematodes, such as nematophagous fungi that set traps to capture and digest nematodes (13). The perception of ascarosides is sufficient to trigger trap formation in these fungi, demonstrating their longstanding evolutionary association with nematodes. Furthermore, ascarosides produced by plant-pathogenic nematodes have been shown to trigger innate immune responses in monocot and dicot plants (14). Cumulatively, these findings suggest that ascarosides represent a nematode-specific molecular signature that is recognized and interpreted by nematode predators and hosts across multiple kingdoms.In this study, we collected ES products from the gut-resident, rodent-parasitic nematode Nippostrongylus brasiliensis. Previous studies showed that the administration of N. brasiliensis ES (NES) products fully inhibits the development of airway hyperresponsiveness (AHR) in the ovalbumin (OVA) murine model of asthma (15). Specifically, NES products substantially prevented lung eosinophilia, mucus production, and resistance to airflow. Notably, it was found that heat-treated or proteinase K–treated NES mimicked the full effect of untreated NES products in reducing lung eosinophilia and OVA-specific IgG in serum. Therefore, we hypothesized that the therapeutic effect of NES products may be due to the presence of specific small molecules that may in part be bound to secreted proteins, explaining the activity of heat- or proteinase K–treated NES. To test this hypothesis, we isolated the small molecule fraction of heat-treated NES (small molecule ES [smES]) products via filtration through a 3-kDa filter and found that smES products strongly suppresses OVA-induced allergic immune responses. Parallel chemical analyses of several other mammalian parasitic nematodes confirmed the presence of specific ascarosides in smES products of all tested species. Next, we tested synthetic samples of ascarosides and found that ascr#7, a compound produced by N. brasiliensis and other parasitic species, markedly inhibited the development of allergic airway inflammation, comparable to the full effect of smES products. Mechanistically, we found that ascr#7 administration attenuated IL-33 production from lung epithelial cells and suppressed the proliferation of memory-type IL-5–producing pathogenic T helper 2 (Th2) cells and type 2 innate lymphoid cells (ILC2s) in the lung, both key drivers for the pathology of asthma. We thus demonstrate that ascarosides have an immunomodulatory role that attenuates OVA-induced allergic inflammation in a murine model.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号