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   6840篇
  免费   426篇
  国内免费   33篇
耳鼻咽喉   80篇
儿科学   230篇
妇产科学   97篇
基础医学   1009篇
口腔科学   322篇
临床医学   501篇
内科学   1688篇
皮肤病学   254篇
神经病学   584篇
特种医学   85篇
外科学   690篇
综合类   28篇
一般理论   2篇
预防医学   669篇
眼科学   185篇
药学   452篇
中国医学   28篇
肿瘤学   395篇
  2024年   12篇
  2023年   88篇
  2022年   172篇
  2021年   311篇
  2020年   188篇
  2019年   265篇
  2018年   262篇
  2017年   185篇
  2016年   185篇
  2015年   233篇
  2014年   299篇
  2013年   399篇
  2012年   622篇
  2011年   642篇
  2010年   304篇
  2009年   261篇
  2008年   426篇
  2007年   415篇
  2006年   385篇
  2005年   348篇
  2004年   318篇
  2003年   258篇
  2002年   237篇
  2001年   33篇
  2000年   35篇
  1999年   65篇
  1998年   34篇
  1997年   25篇
  1996年   20篇
  1995年   16篇
  1994年   15篇
  1993年   11篇
  1992年   21篇
  1991年   16篇
  1990年   16篇
  1989年   16篇
  1988年   12篇
  1987年   12篇
  1986年   10篇
  1985年   13篇
  1984年   9篇
  1983年   13篇
  1982年   6篇
  1980年   10篇
  1979年   9篇
  1977年   6篇
  1974年   6篇
  1973年   6篇
  1970年   6篇
  1969年   5篇
排序方式: 共有7299条查询结果,搜索用时 15 毫秒
101.
102.

Objective:

to validate an instrument to measure self-confidence of nursing care in urinary retention.

Methods:

methodological research study, carried out after ethical approval. A Likert-like scale of 32 items related to nursing care in urinary retention was applied to students of the graduate nursing course. For instrument validation, analysis of the sample adequacy and main components, Varimax orthogonal rotation and internal consistency analyses were developed.

Results:

in a sample of 305 students, there was high correlation of all items with the total scale and Cronbach''s alpha of 0.949. The scale items were divided into five factors with internal consistency: Factor 1 (0.890), Factor 2 (0.874), Factor 3 (0.868), Factor 4 (0.814) and Factor 5 (0.773), respectively.

Conclusion:

the scale meets the validity requirements, demonstrating potential for use in evaluation and research.  相似文献   
103.
Abstract

Purpose: A prevalence survey for active trachoma in children aged under 10 years and trichiasis in women aged 40 years and older was carried out in four districts in the Sololá region in Guatemala, which is suspected of still having a trachoma problem.

Methods: Population-based surveys were undertaken in three districts, within 15 randomly selected communities in each district. In addition, in a fourth district that borders the third district chosen, we surveyed the small northern sub-district, by randomly selecting three communities in each community, 100 children aged under 10 years were randomly selected, and all females over 40 years. Five survey teams were trained and standardized. Trachoma was graded using the World Health Organization simplified grading scheme and ocular swabs were taken in cases of clinical follicular or inflammatory trachoma. Prevalence estimates were calculated at district and sub-district level.

Results: Trachoma rates at district level varied from 0–5.1%. There were only two sub-districts where active trachoma approached 10% (Nahualá Costa, 8.1%, and Santa Catarina Costa, 7.3%). Trichiasis rates in females aged 40 years and older varied from 0–3%. Trachoma was likely a problem in the past.

Conclusions: Trachoma is disappearing in the Sololá region in Guatemala. Health leadership may consider further mapping of villages around the areas with an especially high rate of trachoma and infection, and instituting trichiasis surgery and active trachoma intervention where needed.  相似文献   
104.
105.
Metabolic Brain Disease - Schizophrenia is a debilitating mental illness. Levels of oxytocin have been proposed as a biomarker of schizophrenia; however, the observed levels of oxytocin in...  相似文献   
106.
B-chronic lymphocytic leukaemia (B-CLL) is characterized by the accumulation of long-lived CD5+ B lymphocytes. The effect of mitoxantrone, a topoisomerase II inhibitor, on B-CLL cells was studied. Treatment of B-CLL cells for 48 h with mitoxantrone (0.5 μg/ml) induced a decrease in cell viability as determined by MTT assay. The IC50 calculated for the cells of three patients was 0.7 μg/ml for two of them and 1.4 μg/ml for the third. In all three patients the maximum effect was observed with 2 μg/ml. An additive cytotoxic effect was observed when mitoxantrone (0.5 μg/ml) was combined with fludarabine (5 μg/ml). Mitoxantrone induced DNA fragmentation and the proteolytic cleavage of poly(ADP-ribose) polymerase (PARP), a marker of the activation of caspases, in all the patients studied, demonstrating that the cytotoxic effect of mitoxantrone was due to induction of apoptosis. These results suggest that mitoxantrone, and possibly other topoisomerase II inhibitors, may be used in the chemotherapy of B-CLL, and that combination of mitoxantrone with fludarabine or other drugs could improve the effectiveness of the treatment.  相似文献   
107.
Do gender differences in CD4 cell counts matter?   总被引:4,自引:0,他引:4  
OBJECTIVE: To examine the effect of gender on disease progression and whether gender differences in CD4 lymphocyte counts persisted for the entire course from HIV seroconversion until (death from) AIDS. METHODS: CD4 lymphocyte counts were modelled in 221 female and 443 male seroconverters following seroconversion, backwards from AIDS and backwards from death using regression analysis for repeated measurements. RESULTS: In the period before use of highly active antiretroviral therapy (HAART), progression to AIDS and to death were marginally slower in women than in men as assessed by proportional hazards analysis. Women seroconverted for HIV, developed AIDS and died at higher CD4 cell counts than men (women: 815, 146 and 44 x 10(6) cells/l, respectively; men: 727, 49 and 22 x 10(6) cells/l, respectively), although differences were only statistically significant at AIDS onset. Declines in CD4 lymphocyte counts were not significantly affected by gender and absolute differences between men and women were stable, with exception for the trajectory close to AIDS when the decline became steeper for men than women. CONCLUSION: These gender differences in CD4 lymphocyte counts suggest a delay of initiation of therapy in women compared with men (our model predicted that women reach the threshold of starting HAART at about 12 months later than men). If this delay unfavourably influences progression, treatment guidelines should be revised so that women can benefit equally from HAART.  相似文献   
108.
We present a 68-y-old female who had undergone aortocoronary bypass and developed Staphylococcus aureus sternal osteomyelitis. Despite prolonged therapy with different antibiotics and several local debridements and drainage, the wound remained open and suppurative. Only after sternectomy and wide excision of infected costal cartilage was the diagnosis of sternal tuberculosis made, 24 months later. This case illustrates the necessity of a high degree of suspicion to diagnose this very rare entity which coexists with more common causes of sternal osteomyelitis.  相似文献   
109.

Purpose

Chronic granulomatous disease (CGD) is an inherited disorder characterized by defects in phagocyte-derived nicotinamide adenine dinucleotide phosphate oxidase. It is typically diagnosed in childhood and leads to severe, recurrent bacterial or fungal infections. Chorioretinal lesions are the most common ocular manifestation. We sought to determine whether there are infectious agents in CGD-associated chorioretinopathy.

Methods

Medical records and ocular histopathology from CGD cases from January 1983 to January 2012 at the National Institutes of Health were retrospectively reviewed. Chorioretinal cells from normal and lesional tissues of the same eye were microdissected. Primers for Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia sp., and a panbacterial 16S ribosomal DNA were used for polymerase chain reaction.

Results

Seventeen CGD patients had ocular tissues (16 autopsied cases and 1 chorioretinal biopsy) examined. Of these 17, 8 demonstrated CGD-associated chorioretinal lesions in at least one eye on histopathology. Of these 8, 7 showed amplification of 16S ribosomal DNA within the lesion; of these 7, two also amplified S. epidermidis and one P. aeruginosa. One had no bacterial DNA amplified. Importantly, no microbial DNA was amplified from the normal, non-lesional ocular tissues of these 8 cases. Furthermore, only 1 of the 9 eyes without chorioretinopathy had amplified Burkholderia DNA, that patient had a history of Burkholderia infection.

Conclusions

We detected bacterial DNA in 7 of 8 (88 %) cases with CGD-associated chorioretinopathy and only in 1 normal ocular tissue of 17 CGD cases. Bacterial infection may play a role in the pathogenesis of CGD-associated chorioretinal lesions.  相似文献   
110.
Journal of Neurology - SPG4 is an autosomal dominant pure form of hereditary spastic paraplegia (HSP) caused by mutations in the SPAST gene. HSP is considered an upper motor neuron disorder...  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