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   915篇
  免费   41篇
  国内免费   8篇
耳鼻咽喉   1篇
儿科学   31篇
妇产科学   17篇
基础医学   114篇
口腔科学   15篇
临床医学   61篇
内科学   249篇
皮肤病学   8篇
神经病学   68篇
特种医学   27篇
外科学   193篇
综合类   4篇
预防医学   61篇
眼科学   20篇
药学   56篇
中国医学   6篇
肿瘤学   33篇
  2024年   2篇
  2023年   15篇
  2022年   19篇
  2021年   41篇
  2020年   17篇
  2019年   37篇
  2018年   44篇
  2017年   16篇
  2016年   22篇
  2015年   26篇
  2014年   45篇
  2013年   53篇
  2012年   70篇
  2011年   60篇
  2010年   52篇
  2009年   35篇
  2008年   57篇
  2007年   37篇
  2006年   49篇
  2005年   42篇
  2004年   46篇
  2003年   47篇
  2002年   42篇
  2001年   6篇
  2000年   8篇
  1999年   6篇
  1998年   4篇
  1996年   6篇
  1995年   6篇
  1994年   2篇
  1993年   3篇
  1992年   4篇
  1991年   3篇
  1990年   5篇
  1989年   3篇
  1988年   1篇
  1987年   5篇
  1986年   4篇
  1985年   2篇
  1984年   2篇
  1982年   1篇
  1981年   4篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   4篇
  1975年   1篇
  1973年   3篇
  1971年   2篇
  1968年   1篇
排序方式: 共有964条查询结果,搜索用时 15 毫秒
71.

Aim  

The aim of this study was to analyze the epidemiological issues related to suicide in Ecuadorians.  相似文献   
72.
A case of primary intradural chordoma at thoracic level is presented. This report confirms the presence of ectopic intradural chordomas within the spinal canal. It is necessary to include these lesions in the differential diagnosis of intradural-extramedullary tumors.  相似文献   
73.
The purpose of this case report is to describe the effects of a cortisone injection and a conservative, non-operative physical therapy approach in a patient with anterior instability of the glenohumeral joint. A 73-year-old, right-handed male was referred to physical therapy following a right shoulder subluxation, resulting in pain and decreased function in the right upper extremity. A baseline examination indicating significant pain and right shoulder dysfunction resulted in an initial Western Ontario Shoulder Instability Index (WOSI) score of 1619. The patient was seen for 22 visits divided into Phase I and Phase II. Phase II began following a cortisone injection received after visit 15. Physical Therapy intervention consisted of shoulder pendulum exercises, active ROM, Maitland mobilization, strengthening of rotator cuff and thoracic musculature, electrical stimulation and cryotherapy. WOSI scores at baseline, the conclusion of Phase I and II, and one month post discharge were recorded. They were 1487 (8% improvement), 116 (93% improvement), and 83 (95% improvement), respectively. Percent improvement was calculated based on the initial WOSI score. The patient's WOSI score at discharge (end of Phase II) was similar to his self-report of improvement (95%). Results of the WOSI at the conclusion of Phase I and Phase II suggest that the anti-inflammatory and analgesic effects of a cortisone injection were critical components in the patient's recovery. These findings may indicate the appropriateness of such an injection in cases with significant pain and inflammation when a more traditional, conservative approach to anterior glenohumeral joint instability proves ineffective.  相似文献   
74.
Activated B cells reshape their primary antibody repertoire after antigen encounter by two molecular mechanisms: somatic hypermutation (SHM) and class switch recombination (CSR). SHM and CSR are initiated by activation-induced cytidine deaminase (AID) through the deamination of cytosine residues on the immunoglobulin loci, which leads to the generation of DNA mutations or double-strand break intermediates. As a bystander effect, endogenous AID levels can also promote the generation of chromosome translocations, suggesting that the fine tuning of AID expression may be critical to restrict B cell lymphomagenesis. To determine whether microRNAs (miRNAs) play a role in the regulation of AID expression, we performed a functional screening of an miRNA library and identified miRNAs that regulate CSR. One such miRNA, miR-181b, impairs CSR when expressed in activated B cells, and results in the down-regulation of AID mRNA and protein levels. We found that the AID 3' untranslated region contains multiple putative binding sequences for miR-181b and that these sequences can be directly targeted by miR-181b. Overall, our results provide evidence for a new regulatory mechanism that restricts AID activity and can therefore be relevant to prevent B cell malignant transformation.  相似文献   
75.
The humoral immune response critically relies on the secondary diversification of antibodies. This diversification takes places through somatic remodelling of the antibody genes by two molecular mechanisms, Class Switch Recombination (CSR) and Somatic Hypermutation (SHM). The enzyme Activation Induced Cytidine Deaminase (AID) initiates both SHM and CSR by deaminating cytosine residues on the DNA of immunoglobulin genes. While crucial for immunity, AID-catalysed deamination is also the triggering event for the generation of lymphomagenic chromosome translocations. To address whether restricting the levels of AID expression in vivo contributes to the regulation of its function, we analysed mice harbouring a single copy of the AID gene (AID+/−). AID+/− mice express roughly 50% of normal AID levels, and display a mild hyperplasia, reminiscent of AID deficient mice and humans. Moreover, we found that AID+/− cells have an impaired competence for CSR and SHM, which indicates that AID gene dose is limiting for its physiologic function. We next evaluated the impact of AID reduction in AID+/− mice on the generation of chromosome translocations. Our results show that the frequency of AID-promoted c-myc/IgH translocations is reduced in AID+/− mice, both in vivo and in vitro. Therefore, AID is haploinsufficient for antibody diversification and chromosome translocations. These findings suggest that limiting the physiologic levels of AID expression can be a regulatory mechanism that ensures an optimal balance between immune proficiency and genome integrity.  相似文献   
76.
77.
The frequency of Entamoeba histolytica and Entamoeba dispar infection was analyzed in a rural community in the state of Morelos, Mexico, using polymerase chain reaction (PCR). Sociodemographic variables as risk factors for the infection were assessed. Results highlighted the number of individuals with intestinal parasites (43.1%) in the community, indicating extensive fecalism. A high frequency of E. histolytica asymptomatic infection, higher than E. dispar infection (13.8% versus 9.6%), was detected by PCR. Anti-amebic antibody levels (IgG) in serum and saliva (IgA) samples were not associated with E. histolytica intestinal infection. These findings suggest a predominant distribution of E. histolytica strains of low invasive potential in this community.  相似文献   
78.

OBJECTIVE

To determine whether pharmacological treatment of depression in low-income minorities with diabetes improves A1C and quality of life (QOL).

RESEARCH DESIGN AND METHODS

This was a 6-month, randomized, double-blind, placebo-controlled trial. Patients were screened for depression using Whooley''s two-question tool at a county diabetes clinic. Depression was confirmed (or not) with the Computerized Diagnostic Interview Survey (CDIS) software program, and the severity of depression was assessed monthly by the Hamilton Depression Scale (HAM-D). Depressed subjects with A1C levels ≥8.0% were randomly assigned to receive either sertraline or placebo. Diabetes care was provided by nurses following detailed treatment algorithms who were unaware of therapy for depression.

RESULTS

A total of 150 subjects answered positively to at least one question on Whooley''s questionnaire. The positive predictive value for depression diagnosed by CDIS was 69, 67, and 84% for positive answers to question 1 only, question 2 only, or both, respectively. Of the 89 subjects who entered the study, 75 completed. An intention-to-treat analysis revealed significant differences between baseline and 6 months in HAM-D and pain scores, QOL, and A1C and systolic blood pressure levels in both groups, with no differences between groups for the first three but a significantly greater decrease with sertraline in A1C and systolic blood pressure levels. Changes in HAM-D scores and A1C levels were significantly correlated in all subjects (P = 0.45 [P < 10−6]).

CONCLUSIONS

In this low-income minority population, pharmacological treatment of depression significantly improved A1C and systolic blood pressure levels compared with placebo.The prevalence of depression among people with diabetes is more than twice that of the general population (1). Coexistence of depression in persons with diabetes is associated with worse glycemic control (2), which may be due to less adherence to self-care behaviors and medications (3). Eventually, there is increased morbidity (4) and mortality (5) and higher medical costs (6).The prevalence of untreated depression in people with diabetes is higher in minorities (1). Yet, screening for and treating depression are less common in this population (7). Very little research has been published on diabetes and depression with a focus on minority populations, who have significant disparities in outcomes (8), such as higher A1C levels (9), increased rates of complications (10), and more severe depression (8).Depression is associated with worse glycemic control (2). Some studies have evaluated whether treatment of depression will improve A1C levels (1120). However, these drug studies were open label, were of short duration, and/or were conducted in highly educated (more than high school education) Caucasian populations. Most showed that although depression was improved, A1C levels were not. We sought to determine whether use of antidepressants in a minority population with uncontrolled diabetes improved their A1C levels, quality of life (QOL), and depression compared with placebo.  相似文献   
79.
80.
PURPOSE: To report an illustrative case demonstrating the efficacy of endovascular treatment for traumatic blunt renal allograft injury. CASE REPORT: A 19-year-old man sustained an injury to his renal allograft after a traffic accident secondary to lap belt compression. Angiography revealed contrast extravasation from 2 disrupted upper pole renal artery branches, which were successfully embolized with microcoils. The creatinine level was transiently elevated to 4.1 mg/dL, but it improved to 2.9 mg/dL at discharge 13 days after admission. After 1 year, the serum creatinine level was 1.9 mg/dL. CONCLUSION: As in the native kidney, superselective embolization can also be used safely in the management of blunt injury to a renal allograft, avoiding surgery and preserving graft function.  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