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   3923篇
  免费   182篇
  国内免费   30篇
耳鼻咽喉   9篇
儿科学   93篇
妇产科学   14篇
基础医学   440篇
口腔科学   71篇
临床医学   290篇
内科学   1196篇
皮肤病学   57篇
神经病学   185篇
特种医学   166篇
外科学   858篇
综合类   14篇
预防医学   59篇
眼科学   42篇
药学   220篇
中国医学   19篇
肿瘤学   402篇
  2023年   17篇
  2022年   50篇
  2021年   81篇
  2020年   49篇
  2019年   64篇
  2018年   93篇
  2017年   102篇
  2016年   89篇
  2015年   122篇
  2014年   134篇
  2013年   181篇
  2012年   254篇
  2011年   289篇
  2010年   157篇
  2009年   145篇
  2008年   209篇
  2007年   246篇
  2006年   243篇
  2005年   264篇
  2004年   251篇
  2003年   246篇
  2002年   207篇
  2001年   46篇
  2000年   42篇
  1999年   53篇
  1998年   38篇
  1997年   31篇
  1996年   37篇
  1995年   38篇
  1994年   23篇
  1993年   21篇
  1992年   27篇
  1991年   22篇
  1990年   29篇
  1989年   24篇
  1988年   21篇
  1987年   23篇
  1986年   18篇
  1985年   19篇
  1984年   17篇
  1983年   12篇
  1982年   9篇
  1981年   14篇
  1980年   12篇
  1979年   9篇
  1978年   12篇
  1977年   8篇
  1975年   4篇
  1974年   8篇
  1973年   5篇
排序方式: 共有4135条查询结果,搜索用时 30 毫秒
181.
AIM: To investigate the efficacy of angiotensin II receptor antagonist on hepatic stellate cells (HSCs) activation in the patients with non-alcoholic steatohepatitis (NASH). METHODS: Seven patients with NASH were prescribed losartan, a selective angiotensin II type 1 receptor antagonist (50 mg/d) for 48 wk. Liver biopsies were performed both at the entry and end of the study in all patients. Quiescent and activated HSCs were identified by double immunostaining using anti-p75 and -smooth muscle actin antibodies, and the number of each phenotype was counted. Similarly, the liver specimens obtained from the eight patients with non-alcoholic fatty liver (NAFL) were also examined as controls. RESULTS: In NASH hepatic tissues, activated HSCs were dominantly distributed as compared with those in NAFL. The 48-wk losartan treatment induced a remarkable decrease in activated HSCs and a mild increase in quiescent phenotypes. CONCLUSION: Our data suggest the crucial involvement of HSCs in anti-fibrotic effect of angiotensin II receptor antagonist on patients with NASH.  相似文献   
182.
Diffuse large B-cell lymphoma (DLBCL) comprises molecularly distinct subgroups such as activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCLs. We previously reported that CD5(+) and CD5(-)CD10(+) DLBCL constitute clinically relevant subgroups. To determine whether these 2 subgroups are related to ABC and GCB DLBCLs, we analyzed the genomic imbalance of 99 cases (36 CD5(+), 19 CD5(-)CD10(+), and 44 CD5(-)CD10(-)) using array-based comparative genomic hybridization (CGH). Forty-six of these cases (22 CD5(+), 7 CD5(-)CD10(+), and 17 CD5(-)CD10(-)) were subsequently subjected to gene-expression profiling, resulting in their division into 28 ABC (19 CD5(+) and 9 CD5(-)CD10(-)) and 18 GCB (3 CD5(+), 7 CD5(-)CD10(+), and 8 CD5(-)CD10(-)) types. A comparison of genome profiles of distinct subgroups of DLBCL demonstrated that (1) ABC DLBCL is characterized by gain of 3q, 18q, and 19q and loss of 6q and 9p21, and GCB DLBCL is characterized by gain of 1q, 2p, 7q, and 12q; (2) the genomic imbalances characteristic of the CD5(+) and CD5(-)CD10(+) groups were similar to those of the ABC and GCB types, respectively. These findings suggest that CD5(+) and CD5(-)CD10(+) subgroups are included, respectively, in the ABC and GCB types. Finally, when searching for genomic imbalances that affect patients' prognosis, we found that 9p21 loss (p16(INK4a) locus) marks the most aggressive type of DLBCL.  相似文献   
183.

Background

In severe drug eruptions, precise evaluation of disease severity at an early stage is needed to start appropriate treatment. It is not always easy to diagnose these conditions at their early stage. In addition, there are no reported prognostic biomarkers of disease severity in drug eruptions. The aim of this study was to test whether the thymus and activation-regulated chemokine (TARC) level in serum at an early stage of a drug eruption can serve as a prognostic biomarker of systemic inflammation.

Methods

Study participants included 76 patients who received a diagnosis of a drug eruption, one of the following: drug rash with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome, maculopapular exanthema, and erythema multiforme. Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) was eliminated in this study because scoring system for evaluating the severity was established. Correlation coefficients between serum TARC levels and indicators of systemic inflammation, including the neutrophil-to-lymphocyte ratio, Glasgow prognostic score, modified systemic inflammatory response syndrome (mSIRS) score, and C-reactive protein in serum were evaluated.

Results

Serum TARC levels positively correlated with the neutrophil-to-lymphocyte ratio, Glasgow prognostic score, mSIRS score, C-reactive protein, albumin, white blood cell count, body temperature, and pulse rate. TARC levels negatively correlated with systolic blood pressure. Among these parameters, the mSIRS score showed strong correlation (correlation coefficient: 0.68).

Conclusions

Serum TARC levels correlate well with indicators of systemic inflammation and of disease severity among patients with a drug eruption except SJS/TEN. Serum TARC may be a prognostic biomarker of severity of inflammation in drug eruptions.  相似文献   
184.
A small proportion of patients with rheumatoid arthritis (RA) develop idiopathic inflammatory myopathies (IIM); however, the clinical and immunological characteristics of these patients have not been elucidated. In the present study, we evaluate the frequency of autoantibodies and the accompanying clinical features in patients with IIM overlapped to RA (IIM-RA) and in patients with IIM without RA. Twelve patients with IIM-RA were selected from 142 patients with IIM who were admitted to our hospital. Clinical and laboratory data, including autoantibody test results, were collected from patient medical records. Myositis-specific antibodies (MSAs) were analyzed by immunoprecipitation. Clinically, patients with IIM-RA were more likely to be male, to have polymyositis, and to be older at the time of IIM onset than patients with IIM without RA. Patients with IIM-RA had been treated for 2–25?years prior to the onset of IIM with more than two disease-modifying antirheumatic drugs (DMARDs). Patients with IIM-RA had a high frequency (75.0%) of positivity for MSAs, including anti-Jo-1, anti-PL-7, anti-PL-12, or anti-signal recognition particle (SRP) antibodies; anti-Jo-1 antibody was detected in 4 patients (33.3%). In addition, 2 out of 12 patients with IIM-RA were concurrently positive for two different MSAs, anti-Jo-1, and anti-PL-7 antibodies. In 3 other patients with IIM-RA, anti-Jo-1 antibody, or anti-PL-7 antibody was detected in serum samples collected 6–18?months prior to development of myositis. High frequency and coexistence of MSAs were detected in patients with IIM-RA. MSAs detected in patients with RA even without symptoms of myositis may indicate possible future development of myositis.  相似文献   
185.
186.
Olfactory bulbectomy (OBX) in mice elicits impaired memory and cognitive functions. Here, we found that chronic oral administration of spiro[imidazo[1,2-a]pyridine-3,2-indan]-2(3H)-one (ZSET1446/ST101) (0.1-1 mg/kg/day), a novel cognitive enhancer, significantly improved memory deficits as assessed by Y-maze and novel object recognition tasks in OBX mice. Immunostaining of cholinergic neurons in the medial septum by using an anti-choline acetyltransferase antibody indicated that chronic ZSET1446 treatment did not rescue cholinergic neurons. However, chronic treatment significantly restored OBX-induced decreases both in calcium/calmodulin-dependent protein kinase II (CaMKII) and protein kinase C (PKC) phosphorylation without improving decreased extracellular signal-regulated kinase phosphorylation in the hippocampal CA1 region. Consistent with enhanced CaMKII and PKC phosphorylation, ZSET1446 treatment improved glutamate receptor 1 (Ser-831) phosphorylation in the hippocampal CA1 region. ZSET1446 treatment also significantly rescued impaired long-term potentiation (LTP) in the hippocampal CA1 region of OBX mice. Taken together, the cognition-enhancing effect of ZSET1446 is probably mediated in part by stimulation of CaMKII and PKC activities, which in turn rescue impaired hippocampal LTP in OBX mice.  相似文献   
187.
Rationale:Hepatitis-associated aplastic anemia (HAAA) is a rare illness that results in bone marrow failure following hepatitis development. The etiological agent remains unknown in most HAAA cases. However, clinical features of the disease and immunotherapy response indicate that immune-mediated factors play a central role in the pathogenesis of HAAA. Activation of cytotoxic T cells and increase in CD8 cells could exert cytotoxic effects on the myelopoietic cells in the bone marrow.Patient concerns:A 15-month-old boy was brought to our hospital with complaints of generalized petechiae and purpura observed a week prior to hospitalization. His liver was palpated 3 cm below the costal margin, platelet count was 0 × 104/μL, and alanine aminotransferase level was 1346 IU/L. A blood test indicated cytomegalovirus infection, and 3 bone marrow examinations revealed progressive HAAA. As the disease progressed to the 3rd, 6th, and 9th week after onset, CD4+ T cells were markedly decreased, CD8+ T cells were markedly increased, and the CD4/CD8 ratio was significantly decreased. The number of B cells and natural killer cells decreased with time, eventually reaching 0.0%.Diagnosis:HAAA.Interventions:Rabbit antithymocyte globulin and eltrombopag olamine (a thrombopoietin receptor agonist) were administered.Outcomes:The patient''s platelet count returned to normal, and bone marrow transplantation was avoided. The peripheral blood lymphocytes (PBLs) improved as the patient''s general condition recovered.Lessons:This case demonstrates that HAAA induced by cytomegalovirus infection features decreasing CD4+ and increasing CD8+ PBLs as the bone marrow hypoplasia progresses. The PBLs return to their normal levels with the recovery from the disease. Our case findings thus support the involvement of immunological abnormality in HAAA.  相似文献   
188.
Sterile chronic inflammation causes cardiometabolic disorders; however, the mechanisms are not fully understood. Previous studies have demonstrated the degradation of cells/tissues in the vasculature and metabolic organs in lifestyle-associated diseases, such as diabetes and hyperlipidemia, suggesting the release and/or accumulation of nucleic acids from damaged cells. DNA is indispensable for life; however, DNA fragments, especially those from pathogens, strongly induce inflammation by the activation of DNA sensors. Growing evidence suggests that DNA-sensing mechanisms, which are normally involved in self-defense against pathogens as the innate immune system, are associated with the progression of inflammatory diseases in response to endogenous DNA fragments. There are several types of DNA sensors in our bodies. Toll-like receptor 9 (TLR9)—one of the most studied DNA sensors—recognizes DNA fragments in endosome. In addition, stimulator of interferon genes (STING), which has recently been extensively investigated, recognizes cyclic GMP-AMP (cGAMP) generated from DNA fragments in the cytosol. Both TLR9 and STING are known to play pivotal roles in host defense as the innate immune system. However, recent studies have indicated that the activation of these DNA sensors in immune cells, such as macrophages, promotes inflammation leading to the development of vascular and metabolic diseases associated with lifestyle. In this review, we discuss recent advances in determining the roles of DNA sensors in these disease contexts. Revealing a novel mechanism of sterile chronic inflammation regulated by DNA sensors might facilitate clinical interventions for these health conditions.  相似文献   
189.
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus. It involves multiple organ systems, including the lungs. However, the significance of the lung involvement in SFTS remains unclear. In the present study, we aimed to investigate the relationship between the clinical findings and abnormalities noted in the chest computed tomography (CT) of patients with SFTS. The medical records of 22 confirmed SFTS patients hospitalized in five hospitals in Nagasaki, Japan, between April 2013 and September 2019, were reviewed retrospectively. Interstitial septal thickening and ground-glass opacity (GGO) were the most common findings in 15 (68.1%) and 12 (54.5%) patients, respectively, and lung GGOs were associated with fatalities. The SFTS patients with a GGO pattern were elderly, had a disturbance of the conscious and tachycardia, and had higher c-reactive protein levels at admission (p = 0.009, 0.006, 0.002, and 0.038, respectively). These results suggested that the GGO pattern in patients with SFTS displayed disseminated inflammation in multiple organs and that cardiac stress was linked to higher mortality. Chest CT evaluations may be useful for hospitalized patients with SFTS to predict their severity and as early triage for the need of intensive care.  相似文献   
190.
The clinical course and surgical repair of double-outlet left atrium with intact ventricular septum in a 13-year-old girl are presented. The only outlet of the right atrium was a secundum atrial septal defect, and the left atrium drained into both ventricles through two atrioventricular valves. To our knowledge, there has been only one other published report of repair of double-outlet left atrium.  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