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   3366篇
  免费   185篇
  国内免费   30篇
耳鼻咽喉   103篇
儿科学   135篇
妇产科学   166篇
基础医学   213篇
口腔科学   136篇
临床医学   275篇
内科学   742篇
皮肤病学   117篇
神经病学   193篇
特种医学   118篇
外科学   816篇
综合类   46篇
预防医学   120篇
眼科学   129篇
药学   140篇
中国医学   7篇
肿瘤学   125篇
  2024年   2篇
  2023年   20篇
  2022年   28篇
  2021年   62篇
  2020年   47篇
  2019年   72篇
  2018年   92篇
  2017年   64篇
  2016年   134篇
  2015年   116篇
  2014年   150篇
  2013年   179篇
  2012年   252篇
  2011年   231篇
  2010年   136篇
  2009年   169篇
  2008年   321篇
  2007年   322篇
  2006年   266篇
  2005年   272篇
  2004年   204篇
  2003年   156篇
  2002年   102篇
  2001年   47篇
  2000年   43篇
  1999年   24篇
  1998年   5篇
  1997年   8篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1992年   4篇
  1991年   7篇
  1990年   8篇
  1989年   6篇
  1988年   7篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1979年   3篇
  1978年   2篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有3581条查询结果,搜索用时 279 毫秒
1.
2.
This review discusses the interplay between multimorbidity (i.e. co‐occurrence of more than one chronic health condition in an individual) and functional impairment (i.e. limitations in mobility, strength or cognition that may eventually hamper a person's ability to perform everyday tasks). On the one hand, diseases belonging to common patterns of multimorbidity may interact, curtailing compensatory mechanisms and resulting in physical and cognitive decline. On the other hand, physical and cognitive impairment impact the severity and burden of multimorbidity, contributing to the establishment of a vicious circle. The circle may be further exacerbated by people's reduced ability to cope with treatment and care burden and physicians’ fragmented view of health problems, which cause suboptimal use of health services and reduced quality of life and survival. Thus, the synergistic effects of medical diagnoses and functional status in adults, particularly older adults, emerge as central to assessing their health and care needs. Furthermore, common pathways seem to underlie multimorbidity, functional impairment and their interplay. For example, older age, obesity, involuntary weight loss and sedentarism can accelerate damage accumulation in organs and physiological systems by fostering inflammatory status. Inappropriate use or overuse of specific medications and drug–drug and drug–disease interactions also contribute to the bidirectional association between multimorbidity and functional impairment. Additionally, psychosocial factors such as low socioeconomic status and the direct or indirect effects of negative life events, weak social networks and an external locus of control may underlie the complex interactions between multimorbidity, functional decline and negative outcomes. Identifying modifiable risk factors and pathways common to multimorbidity and functional impairment could aid in the design of interventions to delay, prevent or alleviate age‐related health deterioration; this review provides an overview of knowledge gaps and future directions.  相似文献   
3.
This study aimed to determine the effect of acute brucellosis on the auditory system. Forty-two patients with acute brucellosis were evaluated clinically, and with serological and audiological tests, before and after treatment. Hearing threshold averages were calculated at 11 different frequencies (250-8000 Hz) of the auditory airway, and statistical analysis was performed. The average hearing thresholds were > 20 dB, with standard audiometry at 6000-8000 Hz, and < 20 dB at all other frequencies. After treatment, the average auditory threshold decreased to < 20 dB at 6000-8000 Hz (p < 0.0001). Pure-tone hearing thresholds were improved at all frequencies after treatment, with statistically significant differences at all frequencies except 12,000, 14,000 and 16 000 Hz (p < 0.05). There was no permanent hearing loss caused by acute brucellosis, and hearing thresholds were restored after treatment. It was concluded that acute brucellosis affects the auditory system, especially at high frequencies, and that patients with all forms of brucellosis should be evaluated for hearing loss.  相似文献   
4.
It is well known that there might be an epidemiological association between Helicobacter pylori infection and extraintestinal diseases. This study aimed at determining H. pylori infection in epileptic patients. Forty-seven cryptogenic epileptic patients (Group 1) and 35 healthy people (Group 2) participated in this study. Presence of H. pylori infection was examined by H. pylori stool antigen (HpSA), H. pylori IgG, and IgM. HpSA was detected in 21 participants (44.6%) in Group 1 and in 3 participants (8.5%) in Group 2. H. pylori IgM was positive in 27 participants (57.4%) in Group 1 and in 8 participants (22.8%) in Group 2. H. pylori IgG was positive in 37 participants (78.7%) in Group 1 and in 13 participants (38%) in Group 2. The difference of rates of HpSA, H. pylori IgM and IgG in Groups 1 and 2 were found statistically significant (chi2=4.18, p=0.04; chi2=9.18, p=0.0017; chi2=14.58, p<0.001, respectively). We also compared presence of H. pylori infection between the epileptic patients with poor and good prognosis; HpSA positivity was detected in 15 (62.5%) of 24 and 6 (26%) of 23, respectively, and the differences were statistically significant (chi2=6.30, p=0.012). H. pylori IgM positivity was detected in 16 (66%) of 24 patients with poor prognosis and 11 (47.8%) of 23 patients with good prognosis (p>0.05). H. pylori IgG positivity was detected in 18 (75%) of 24 patients with poor prognosis and 19 (82.6%) of 23 patients with good prognosis. The differences of H. pylori IgM and IgG positivity rates in epileptic patients with poor and good prognosis were not found statistically significant (p>0.05). These results suggest a probable association between the acute H. pylori infection and epilepsy, especially with poor prognosis.  相似文献   
5.
Bone scintigraphy of the hands and wrists represents an important adjunct imaging technique that complements plain film radiographic examination in the evaluation of chronic wrist pain. In this study, the effectiveness of bone scintigraphy was investigated in the evaluation of chronic wrist pain in the patients without the history of trauma and any radiological and rheumatological abnormalities. Seventy-one patients with normal conventional radiographs and unexplained wrist pain were evaluated prospectively between 1998 and 2003 in our hand surgery clinic. There was no trauma history and no specific physical examination findings in the patients. The bone scintigraphy was done in all patients. Fifty-two of the all patients had normal scintigram. Seventeen of the remaining 19 patients showed increased activity over triquetrum (5 cases), lunatum (4 cases), trapezium (4 cases), hamatum (2 cases) and psiforme (2 cases). As the additional radiological investigations like MRI and CT revealed no bony abnormalities, the results of bone scintigraphy were evaluated as chronic ligamentous injuries. Two patients had diffuse increased uptake compatible with synovitis. The evaluation of bone scintigraphy correlated with clinical findings is effective to choose the most efficient treatment method in chronic wrist pain.  相似文献   
6.
CONTEXT: Increasing evidences from experimental and human studies suggest that the activity of the growth hormone (GH/insulin-like growth factor-I) axis may contribute to the age-related cognitive decline and poor cognition in late life. OBJECTIVE: The aim of the present study was to evaluate the relationship of total serum free IGF-I and its binding protein-3 with cognitive performance in older persons aged 80 years or older. DESIGN: Data are from baseline evaluation of the ilSIRENTE study (n=353). Cognitive performance was evaluated using five items enclosed in the Minimum Data Set for Home Care assessment form: short-term memory, procedural memory, cognitive skills in daily decision making, verbal expression, comprehension. Free insulin-like growth factor-I (free IGF-I) and IGF-binding protein-3 (IGFBP-3) in blood were measured. Analysis of covariance (ANCOVA) was used to examine the relationship between cognitive impairment and the serum free IGF-I and IGFBP-3 concentrations, after adjustment for potential confounding variables. RESULTS: After adjustment for potential confounders, which included age, gender, education, cerebrovascular disease, ischemic heart disease, congestive heart failure, hypertension, diabetes, depression, Parkinson diseases, thyroid diseases, smoking status, alcohol abuse, body mass index, and number of medications, individuals with verbal expression problems (n=20) and individuals with comprehension problems (n=24) had a significantly lower serum levels of readily dissociable IGF-I than participants without cognitive impairments. The serum IGFBP-3 presented the same behavior of free IGF-I. CONCLUSION: The present study suggests that among old-old subjects living in the community lower levels of total serum free IGF-I and IGFBP-3 are associated with impairment of cognitive performance. This finding suggests that the GH/IGF-I axis may play an important role in the age-related decline of cognitive performance.  相似文献   
7.
We describe a case of neonatal osteofibrous dysplasia that was diagnosed 3 days after birth. Osteofibrous dysplasia is a fibro-osseous lesion rarely seen in long bones. It is also known as congenital osteitis fibrosa or ossifying fibroma of bones. Although it occurs in children under 10 years of age, it is extremely rare in newborn babies. It must be differentiated from adamantinoma due to their radiological appearance, predilection for tibia and fibula, clinical picture, and certain histological similarities.  相似文献   
8.
Epidermal growth factor receptor plays an important role in the pathogenesis of many malignancies. Various growth factors, including epidermal growth factor receptor, have been shown to influence pituitary tumor growth and differentiation. To analyze the role of epidermal growth factor receptor in pituitary tumor development, we examined normal pituitaries (n=8), pituitary adenomas (n=158), and pituitary carcinomas (n=7) for expression of epidermal growth factor receptor protein and messenger RNA using tissue microarrays and RT-PCR. We also examined (a) the expression of phospho-epidermal growth factor receptor, the activated form of epidermal growth factor receptor, in pituitary tumors and normal pituitaries by immunohistochemistry and (b) the effects on epidermal growth factor receptor expression of treating pituitary cells (HP75 cell line) with epidermal growth factor. Epidermal growth factor receptor and the phosphorylated variant expression were present in normal pituitary cells. Epidermal growth factor receptor messenger RNA was also detected in normal pituitaries, pituitary adenomas, and carcinomas by in situ hybridization and RT-PCR. Most pituitary adenomas showed expression of epidermal growth factor receptor and the phosphorylated variant. Nonfunctional adenomas showed higher levels of expression of epidermal growth factor receptor (76 vs 34%) and of phospho-epidermal growth factor receptor (26 vs 8%) as compared to functional adenomas. Five of seven pituitary carcinomas showed strong expression of both epidermal growth factor receptor and phospho-epidermal growth factor receptor. When a human pituitary cell line (HP75) was cultured in the presence of epidermal growth factor receptor, there was an increase in the levels of both epidermal growth factor receptor and phospho-epidermal growth factor receptor after 5 h of treatment, thus confirming that epidermal growth factor receptor signaling was active in pituitary tumors. These results indicate that activated epidermal growth factor receptor is expressed in pituitary adenomas and carcinomas. Higher levels in pituitary carcinomas suggest a role in pituitary tumor progression.  相似文献   
9.
Purpose: To evaluate the relationship between glaucoma and Helicobacter pylori (H. pylori) infection. Participants: 137 patients with primary open angle glaucoma (POAG), 85 control subjects and 250 patients with gastric symptoms participated Methods: The presence of H. pylori infection in glaucoma patients, and glaucoma incidence in H. pylori infected patients  相似文献   
10.
Functional decline in frail community-dwelling stroke patients   总被引:1,自引:0,他引:1  
Patients who suffer a stroke event are at high risk of functional decline after the post-acute rehabilitation period. The aim of the present study was the evaluation of factors associated with functional decline in a large sample of older patients with stroke living in the community. The study population consisted of all patients admitted to home care programs after a post-acute rehabilitation program--with at least 1 year of follow-up--in twenty-two Italian Home Health Agencies from 2000 to 2002 (n=1338). For the present study we selected 355 (26%) patients with diagnosis of stroke. After 1 year of in-home care program, 149 out of 355 stroke survivors (42%) had presented a worsening in the activities of daily living (ADL) scale score. In the final adjusted model, patients with cognitive impairment (OR 2.59, 95% CI, 1.45-4.64), pressure ulcer (OR 2.74, 95% CI, 1.45-5.18), urinary incontinence (OR 1.64, 95% CI, 1.01-3.29), or hearing impairment (OR 1.83, 95% CI, 1.02-3.29) were more likely to significantly decline in physical functioning after a period of 1 year in-home care program. Our study documents that functional decline of stroke patients was largely dependent on specific subjects' clinical characteristics. Three of four concomitant disabling conditions associated in our sample with functional decline--pressure ulcer, urinary incontinence, hearing--can be prevented and eventually treated or modified. Appropriate post-acute rehabilitation programs and adequate home care interventions focused on the prevention and treatment of these conditions might be correlated to better outcomes in older post-stroke patients.  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