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   39016篇
  免费   2582篇
  国内免费   97篇
耳鼻咽喉   448篇
儿科学   1435篇
妇产科学   945篇
基础医学   4737篇
口腔科学   462篇
临床医学   6449篇
内科学   6695篇
皮肤病学   402篇
神经病学   3727篇
特种医学   798篇
外国民族医学   1篇
外科学   3589篇
综合类   364篇
一般理论   49篇
预防医学   5818篇
眼科学   403篇
药学   2369篇
中国医学   44篇
肿瘤学   2960篇
  2023年   293篇
  2022年   380篇
  2021年   848篇
  2020年   603篇
  2019年   941篇
  2018年   1094篇
  2017年   812篇
  2016年   853篇
  2015年   945篇
  2014年   1328篇
  2013年   2095篇
  2012年   3038篇
  2011年   3219篇
  2010年   1713篇
  2009年   1551篇
  2008年   2791篇
  2007年   2798篇
  2006年   2736篇
  2005年   2690篇
  2004年   2477篇
  2003年   2200篇
  2002年   2109篇
  2001年   239篇
  2000年   200篇
  1999年   267篇
  1998年   434篇
  1997年   338篇
  1996年   260篇
  1995年   209篇
  1994年   216篇
  1993年   210篇
  1992年   128篇
  1991年   116篇
  1990年   93篇
  1989年   99篇
  1988年   90篇
  1987年   80篇
  1986年   85篇
  1985年   84篇
  1984年   99篇
  1983年   76篇
  1982年   90篇
  1981年   99篇
  1980年   70篇
  1979年   42篇
  1978年   31篇
  1977年   38篇
  1929年   30篇
  1928年   28篇
  1924年   26篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
141.
The use of deep brain stimulation (DBS) to treat movement disorders such as Parkinson's disease, essential tremor, and dystonia is increasing. Although some published literature describes the methods for DBS programming, the time and nursing requirements to run a DBS surgical program have not been examined previously. For this study, we prospectively recorded the time required for both assessments and programming of the DBS from the preoperative period to 1 year after surgery in a variety of patients. Results showed that the mean total time spent programming the stimulator and assessing these patients ranged from 18.0-36.2 hours per patient. It took twice as long to program the stimulator in patients with Parkinson's disease as it did in patients with essential tremor or dystonia. When setting up a program for movement disorders surgery, nursing time spent on patient assessment and programming should be considered in the workload.  相似文献   
142.
BACKGROUND: The life expectancy of individuals with CF has increased to 33 years. Thus, issues such as quality of life and psychological well-being, previously thought to be of lesser importance than physical well-being, are now recognised as significant factors. This study examined the interrelationships between quality of life, family functioning, individual psychopathology and optimism of adolescents with CF. METHODS: Adolescents attending the CF clinic completed a number of questionnaires. Quality of Life was measured using the Cystic Fibrosis Questionnaire, family functioning by the Family Environment Scale (3rd edition), general psychopathology with the Symptom Checklist-90-Revised and optimism for the future by the Hunter Opinions and Personal Expectations Scale. Disease severity was assessed using the Shwachman score and spirometry at the time of questionnaire completion. RESULTS: The level of psychopathology (12.5% of those 13 years and over) in the group was lower than that reported for young people in Australia (15-20%). The results indicated that young people with a delayed diagnosis and those who are alienated from their families may be in need of additional psychosocial support. The group was hopeful and positive about their future and these attributes were independent of clinical measures of disease severity. In general, these young people scored relatively highly on the quality of life scale. For example the mean standardised score for physical functioning was 70 points, for respiratory symptoms was 63 points and for emotional state was 78 points. Increased levels of psychopathology and lack of hope for the future were however associated with lower ratings on a number of quality of life measures. Family cohesiveness, expressiveness and organization were associated with better psychological functioning in the young people. CONCLUSIONS: Adolescents with CF appear to be a psychologically well functioning and well-adjusted group. These findings support the importance of a more sophisticated model of well-being for adolescents with CF, which explores the young person's views on their quality of life and wider support frameworks rather than relying solely on measures of physical health to gauge well-being.  相似文献   
143.
144.
The abuse of older people is a significant problem, with estimates intimating that there may be over 340,000 cases per year in the United Kingdom. Despite improvements in screening and assessment to identify and treat those who are abused or at risk of abuse, the healthcare community remains preoccupied with prevalence rather than prevention. In light of the paucity of health-related research evidence to support the effectiveness of preventative measures, the application of crime prevention theory and knowledge is appropriate. Routine activity theory and situational crime prevention literature acknowledges the vulnerability of older people to abuse and the potential of any person employed as a carer to be an abuser. Preventative measures are focused on techniques that make abuse more difficult and more risky for the perpetrator and, therefore, less 'rewarding'. The regulation of healthcare support workers and increased workplace surveillance are examples of the 25 techniques of situational prevention that could be applied in a healthcare setting.  相似文献   
145.
OBJECTIVE: To characterize dementia-induced changes in visual art production. BACKGROUND: Although case studies show altered visual artistic production in some patients with neurodegenerative disease, no case-controlled studies have quantified this phenomenon across groups of patients. METHOD: Forty-nine subjects [18 Alzheimer disease, 9 frontotemporal dementia (FTD), 9 semantic dementia (SD), 15 healthy older controls (NC)] underwent formal neuropsychologic testing of visuospatial, perceptual, and creative functioning, and produced 4 drawings. Subjective elements of drawings were rated by an expert panel that was blind to diagnosis. RESULTS: Despite equal performance on standard visuospatial tests, dementia groups produced distinct patterns of artistic features that were significantly different from NCs. FTDs used more disordered composition and less active mark-making (P<0.05). Both FTDs and SDs drawings were rated as more bizarre and demonstrated more facial distortion than NCs (P<0.05). Also, SDs drastically failed a standardized test of divergent creativity. Alzheimer disease artwork was more similar to controls than to FTDs or SDs, but showed a more muted color palette (P<0.05) and trends toward including fewer details, less ordered compositions, and occasional facial distortion. CONCLUSIONS: These group differences in artistic style likely resulted from disease-specific focal neurodegeneration, and elucidate the contributions of particular brain regions to the production of visual art.  相似文献   
146.
A 45-year-old woman with history of iritis, uveitis, and sarcoidosis of the skin presented with a subacute cervical myelopathy. Magnetic resonance imaging (MRI) ;howed patchy, multifocal, gadoliniumenhancing intramedullary lesions of the spinal cord, and extramedullary lesions of the basal cisterns and fourth ventricle. Symptoms and MRI abnormalities were improved within 1 month of corticosteroid therapy.  相似文献   
147.
The receptor mGluR5 is a metabotropic glutamate receptor with messenger RNA abundantly present throughout cortex, hippocampus, and caudate/putamen that is also coupled to phosphatidyl inositide hydrolysis and calcium mobilization. In this study, the distribution of mGluR5 was examined in rat brain by immunocytochemistry. The antibody utilized is highly specific and does not cross react with the most closely related other metabotropic glutamate receptor, as determined by Western blot analysis of nonneuronal cells transfected with metabotropic receptor coding sequences. The receptor mGluR5 is widely expressed with the highest density in olfactory bulb, caudate/putamen, lateral septum, cortex, and hippocampus, as confirmed with both immunocytochemistry and Western blot analysis. Electron microscopic studies in hippocampus and cortex indicate that the labeling is mostly on membranes of dendritic spines and shafts. Light and electron microscopic evidence indicates that some mGluR5 immunoreactivity is located in presynaptic axon terminals, suggesting that mGluR5 may function as a presynaptic receptor.  相似文献   
148.
Red-cell adenosine deaminase (ADA) activity in children with Diamond-Blackfan anaemia is significantly increased (1.91 +/- 0.90 U/g Hb) compared to that seen in transient erythroblastopenia of childhood (0.80 +/- 0.16 U/g Hb) or normal individuals (0.61 +/- 0.13 U/g). These data thus further support that measurement of this purine metabolic enzyme is useful in diagnosing the cause of pure RBC aplasia in children. Of interest, however, elevated RBC-ADA activity also is seen in some children with acute leukaemia and other haematologic disorders. In children with acute lymphoblastic leukaemia (ALL), the increase in RBC-ADA activity is proportional to the degree of anaemia. However, the elevated RBC-ADA activity in this leukaemic population is not related to the fetal haemoglobin concentration. These data suggest increased RBC-ADA activity may be a non-specific manifestation of abnormal erythroid stem cell function, an alteration distinct from that seen with reactivation of fetal erythropoiesis. However, since almost all patients with Diamond-Blackfan anaemia manifest elevated RBC-ADA activity, this chemical alteration yet may reflect the specific erythroid differentiation lesion in this disorder.  相似文献   
149.
150.
The range of musculoskeletal disorders encountered in primary care settings is broad, extending from simple injuries to complex chronic diseases. Assessment, management, referral, and pharmacologic intervention for many of these conditions may fall to certified nurse-midwives who increasingly are assuming primary care responsibilities.  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