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   3400篇
  免费   283篇
  国内免费   5篇
耳鼻咽喉   23篇
儿科学   157篇
妇产科学   70篇
基础医学   358篇
口腔科学   92篇
临床医学   425篇
内科学   716篇
皮肤病学   27篇
神经病学   220篇
特种医学   192篇
外科学   572篇
综合类   63篇
预防医学   336篇
眼科学   37篇
药学   236篇
中国医学   2篇
肿瘤学   162篇
  2021年   56篇
  2020年   27篇
  2019年   44篇
  2018年   58篇
  2017年   44篇
  2016年   27篇
  2015年   46篇
  2014年   53篇
  2013年   92篇
  2012年   132篇
  2011年   137篇
  2010年   106篇
  2009年   67篇
  2008年   164篇
  2007年   165篇
  2006年   163篇
  2005年   151篇
  2004年   173篇
  2003年   161篇
  2002年   142篇
  2001年   147篇
  2000年   136篇
  1999年   89篇
  1998年   43篇
  1997年   46篇
  1996年   42篇
  1995年   37篇
  1994年   40篇
  1993年   34篇
  1992年   74篇
  1991年   65篇
  1990年   70篇
  1989年   77篇
  1988年   64篇
  1987年   66篇
  1986年   57篇
  1985年   60篇
  1984年   47篇
  1983年   43篇
  1982年   36篇
  1981年   24篇
  1980年   20篇
  1979年   48篇
  1978年   39篇
  1977年   20篇
  1976年   22篇
  1975年   24篇
  1974年   36篇
  1973年   28篇
  1972年   20篇
排序方式: 共有3688条查询结果,搜索用时 31 毫秒
91.
92.
Neuropsychologists who have considerable experience reflecting, presenting, publishing, and advising on ethical matters are a rich resource for clinicians who have ethics questions. Consultation with such colleagues can be an important part of the ethical decision-making process. The purpose of the present article is to provide the opinions and perspectives of three neuropsychologists who, based on their experience and scholarly activities, served as panelists regarding ethical matters. Although the advice and opinions of colleagues are not a substitute for familiarity with relevant ethical requirements, guidelines, and professional literature, they offer valuable information that enhances the ethical decision-making process.  相似文献   
93.
The use of symptom validity assessment has become commonplace in clinical neuropsychological evaluations. However, clinicians often struggle with how to provide patients with feedback regarding invalid responding or effort, because of the sensitive nature of the information that must be conveyed. A conceptual framework for providing such feedback is outlined in clinical neuropsychological evaluations, and recommendations for how to handle complaints are offered. Our feedback model is not meant to apply to individuals referred by attorneys or other non-clinical third parties (e.g., independent medical examination companies).  相似文献   
94.

Background

Broad autism phenotype (BAP) is a milder expression of the social and communication impairments seen in autism spectrum disorders (ASD). While prior studies characterized the BAP in unaffected family members of probands with ASD, the relationship between parental BAP traits and proband symptomatology remains poorly understood. This study utilizes the Broad Autism Phenotype Questionnaire (BAPQ) in parents and the Social Responsiveness Scale (SRS) in children to examine this connection. We hypothesized that in families affected by ASD, elevated maternal and paternal BAPQ scores would correlate with greater autism symptomatology in diagnosed children. In an extension of prior research, we also explored this relationship in families with typically developing children (TDC).

Methods

Two hundred and forty-five children with ASD, 129 TDC and all parents were recruited as part of a larger study investigating relationships between genes, brain and behavior. The Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS) and expert clinical judgment confirmed ASD diagnoses in children. SRS was collected for all children. Parents completed a self-report BAPQ and an informant report BAPQ for their spouse; an average of self-report and informant report for each parent was used in all analyses.

Results

Mothers and fathers of children with ASD had significantly higher rates of BAP traits as compared to parents of TDC. Maternal and paternal BAPQ total scores were not correlated with child IQ in either group. In the ASD group, 10% of mothers and 21% of fathers scored above the established BAP threshold compared to 4% of TDC parents. Crude regression analyses showed that maternal and paternal BAPQ total scores accounted for significant variance in child SRS scores in both ASD (17.1%) and TDC (19.8%) families.

Conclusions

Our results suggest that broad autism symptomatology in parents is moderately associated with their child’s autism symptomatology. This result extended to TDC families, suggesting that the BAPQ and SRS capture subtle, subclinical social variation in both children and adults. These findings could help define multi-generational social impairments in future phenotypic and genetic studies.  相似文献   
95.

Background

Recreational mountain biking continues to increase in popularity and is a significant source of traumatic injury, including injuries to the hand and wrist.

Methods

A prospective survey of all hand and wrist injuries sustained while participating in recreational mountain biking presenting to the emergency department at the Municipality of Whistler and the District of Squamish was conducted over a 12-month consecutive period.

Results

An analysis of 765 unique emergency department visits with 1,079 distinct injuries was performed. Of these injuries, 511 were sustained to the upper limb. Injury to the metacarpal and metacarpal phalangeal joints was the most common hand injury (52) followed by proximal phalanx and proximal interphalangeal joint (20).

Conclusions

Mountain biking is a frequent source of a variety of upper limb trauma, and preventative efforts are necessary to minimize the burden of these injuries.  相似文献   
96.
Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some na?ve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax.  相似文献   
97.
STUDY OBJECTIVES: Determine the comorbidity of insomnia with medical problems. DESIGN: Cross-sectional and retrospective. PARTICIPANTS: Community-based population of 772 men and women, aged 20 to 98 years old. MEASUREMENTS: Self-report measures of sleep, health, depression, and anxiety. RESULTS: People with chronic insomnia reported more of the following than did people without insomnia: heart disease (21.9% vs 9.5%), high blood pressure (43.1% vs 18.7%), neurologic disease (7.3% vs 1.2%), breathing problems (24.8% vs 5.7%), urinary problems (19.7% vs 9.5%), chronic pain (50.4% vs 18.2%), and gastrointestinal problems (33.6% vs 9.2%). Conversely, people with the following medical problems reported more chronic insomnia than did those without those medical problems: heart disease (44.1% vs 22.8%), cancer (41.4% vs 24.6%), high blood pressure (44.0% vs 19.3%), neurologic disease (66.7% vs 24.3%), breathing problems (59.6% vs 21.4%), urinary problems (41.5% vs 23.3%), chronic pain (48.6% vs 17.2%), and gastrointestinal problems (55.4% vs 20.0%). When all medical problems were considered together, only patients with high blood pressure, breathing problems, urinary problems, chronic pain, and gastrointestinal problems continued to have statistically higher levels of insomnia than those without these medical disorders. CONCLUSION: This study demonstrates significant overlap between insomnia and multiple medical problems. Some research has shown it is possible to treat insomnia that is comorbid with select psychiatric (depression) and medical (eg, pain and cancer) disorders, which in turn increases the quality of life and functioning of these patients. The efficacy of treating insomnia in many of the above comorbid disorders has not been tested, indicating a need for future treatment research.  相似文献   
98.
AIMS: Establishing and maintaining human tumours in primary culture can be challenging. In this application, a short-term primary culture process is desired to ensure cells maintained in culture are representative of the in vivo tumour for the purpose of chemoresponse testing. To ensure the appropriate cells are being grown, the cultures must be evaluated for malignancy. The clinical gold standard determination of malignancy is cytological evaluation by a cytopathologist. METHODS: Fifty human tumour specimens (breast, colon, lung, ovary) were established and maintained in primary culture. Cytospins were prepared upon initiation of culture and again at completion of the culture process. Cytospins were stained (Diff-Quik, Papanicolaou) and evaluated by a cytopathologist for the percentage of malignant cells at both times. RESULTS: An increase in the percentage of malignant cells was noted in 86% (43/50) of the cultures evaluated; 8% (4/50) of the cultures maintained the same percentage of malignant cells throughout the culture period, and 6% (3/50) displayed a decrease in malignant cells. On average, the percentage of malignant cells increased by 37% and was not associated with the length of culture (range 5-28 days). CONCLUSIONS: The described primary culture process enriches for malignant cells, which is desirable for further evaluation such as chemoresponse testing.  相似文献   
99.
The objective of this study was to examine phase- and task-dependent modulation of stretch reflexes during repetitive finger movements in writer’s cramp, and compare them with normal controls from our previous study. A subject with writer’s cramp conducted two rhythmic tasks, index finger abduction (RFA) and a pen-squeezing (RPS) task akin to handwriting. Stretch reflexes were evoked by mechanical perturbations at random phases of each task. Surface electromyograms (EMG) were recorded from two hand muscles, first dorsal interosseous (FDI) and flexor digitorum superficialis (FDS). The reflex response and background EMG activity of each muscle were modulated in a phase-dependent manner in both tasks. However, they varied largely in phase during the RFA task, but in approximately inverse phase-relationship during RPS. Reflex sensitivity, as represented by the slope of the linear regression between response and background, was much lower for both muscles in the ‘writing’ task (RPS) than in the RFA task with its positively correlated responses. These phase- and task-related modulation patterns differed dramatically from those observed in our control subjects, where reflex responses were modulated largely in phase with background activity and reflex sensitivity was much higher, particularly in FDI during RFA and FDS during RPS. The altered reflex modulation patterns in writer’s cramp may reflect deficiencies of integration of proprioceptive afferent inputs and reduced inhibition at cortical and spinal levels during writing performance. Results from this case study support clinically identified task-specific feature of focal hand dystonia.  相似文献   
100.
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