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   1525篇
  免费   110篇
  国内免费   3篇
耳鼻咽喉   31篇
儿科学   32篇
妇产科学   32篇
基础医学   321篇
口腔科学   74篇
临床医学   113篇
内科学   327篇
皮肤病学   37篇
神经病学   164篇
特种医学   24篇
外科学   101篇
综合类   4篇
一般理论   1篇
预防医学   150篇
眼科学   14篇
药学   108篇
中国医学   16篇
肿瘤学   89篇
  2024年   2篇
  2023年   10篇
  2022年   26篇
  2021年   38篇
  2020年   23篇
  2019年   42篇
  2018年   45篇
  2017年   22篇
  2016年   36篇
  2015年   41篇
  2014年   50篇
  2013年   73篇
  2012年   92篇
  2011年   148篇
  2010年   73篇
  2009年   59篇
  2008年   96篇
  2007年   132篇
  2006年   113篇
  2005年   92篇
  2004年   105篇
  2003年   104篇
  2002年   87篇
  2001年   13篇
  2000年   3篇
  1999年   6篇
  1998年   19篇
  1997年   17篇
  1996年   10篇
  1995年   8篇
  1994年   4篇
  1993年   3篇
  1992年   3篇
  1991年   8篇
  1990年   4篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1985年   1篇
  1983年   2篇
  1982年   5篇
  1981年   1篇
  1980年   4篇
  1978年   3篇
  1977年   2篇
  1976年   1篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1969年   2篇
排序方式: 共有1638条查询结果,搜索用时 15 毫秒
121.
Proper solid waste disposal is important to avoid human and environmental contamination. The NBR 10,004 Waste Classification lists several polycyclic aromatic hydrocarbons (PAHs) and indicates that the presence of at least one PAH in a waste sample is enough to classify it as hazardous. The aim of this study was a preliminary evaluation of PAHs in solid waste samples from selected industries to obtain a preliminary overview of their potential for contamination in case of improper disposal. One or more PAHs listed in NBR 10,004 (benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, indene[1,2,3-c,d]pyrene, chrysene, or fluoranthene) were found in all samples, thus leading to their classification as hazardous waste. Our results showed that toxicologically relevant PAHs were found in all the samples, indicating that their final disposal must be performed in appropriate areas in order to minimize human health risks and environmental contamination from waste disposal areas.  相似文献   
122.
This study aims at reporting an experience of offering a course in the master program of the Universidad Nacional de Rosário. The purpose is to offer elements for a reflection on a conception of long-distance education, as an adequate and efficient modality of education, aiming at enabling a teaching with quality to a determined clientele. The course was developed in three moments: video-conference, long-distance didactic activities and a seminar. The tutoring was shared by establishing the challenge of having a dialogic relation with the students. Authors believe that long-distance education is an adequate pedagogical tool to qualify nurses who have no access to traditional graduate studies. Therefore it enables the qualification of a greater number of nurses, geographically dispersed, who are unable to scape from the routine of their personal and professional lives. Facing the need to form the country's nursing workers and qualify nurses to act as teachers, long-distance learning is an effective and possible pedagogical strategy.  相似文献   
123.
Bonilha L  Kobayashi E  Cendes F  Li LM 《Neuroreport》2003,14(10):1291-1295
We assessed the effect of the method of analysis and the MRI slice thickness on entorhinal cortex volumetry. A T1 gradient echo 3D volumetric acquisition was reformatted into different slice thickness and analyzed by edge-tracing. We performed two different forms of analysis of images with 3 mm slice thickness: edge-tracing and pixel by pixel. There was difference among the volumes obtained from different slice thickness (p < 0.001), and also difference between the two different methods of analysis (p < 0.05). The use of thick slices is time saving, but volumes are linearly increased; different methods of segmentation also yields different values.The form of volumetric analysis of the entorhinal cortex should be evaluated in advance to prevent false estimates in longitudinal studies.  相似文献   
124.
The authors studied the time-dependent association between human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) among women enrolled in a cohort study in Brazil (1993-2002), using repeated Papanicolaou cytologic examination and HPV testing by polymerase chain reaction. Through simulation with conceivable alternative cohort designs, they investigated different regression modeling approaches using time-varying covariates, time-varying hazard ratio functions, and repeated events to assess the effect of delay in lesion detection. Associations between HPV and early SIL were of high magnitude. The age-adjusted hazard ratios for the association between HPV at enrollment and low-grade SIL decreased gradually with time until 72 months for both oncogenic types of HPV (hazard ratio = 3.96, 95% confidence interval (CI): 2.5, 6.4) and nononcogenic types (hazard ratio = 2.37, 95% CI: 1.3, 4.3). The hazard ratio for incident high-grade SIL remained constant, ranging from 7.15 (95% CI: 2.0, 25.1) at 12 months to 6.26 (95% CI: 2.7, 14.5) at 72 months for oncogenic types of HPV. With oncogenic HPV as the time-dependent predictor variable, the hazard ratios for incident SIL and high-grade SIL events were 14.2 (95% CI: 8.7, 23.1) and 32.7 (95% CI: 8.4, 127.3), respectively. Investigators may underestimate the prognostic value of HPV detection using designs that rely on HPV ascertainment at a single time point. The waning in hazard ratios should be considered in the implementation of HPV testing-based screening programs.  相似文献   
125.
126.
This paper discusses the legal implications of setting up two new biobanks in Belgium. The first is hospital-based and will archive tissue from patients with haematologic cancer, whereas the second is linked to a general practice based morbidity registry and will involve storage of blood samples. To date, Belgium has no specific legislation that regulates storage of human tissue and related databases. Several issues concerning the protection of individuals with regard to the processing of personal medical data are discussed from the existing privacy legislation. We will address the principle of consent (broad versus specific) and the type of data recorded (anonymous, encoded and identifiable) for both biobanks.  相似文献   
127.
Two different ligands, tritiated oxytocin and a newly synthesized and monoiodinated oxytocin antagonist, were used to reveal sites which bind oxytocin in the brainstem and upper spinal cord of 12 human subjects. Tissue sections were incubated with either ligand at a concentration close to their respective dissociation constants determined in human uterus and rat brain. Specificity of binding was assessed in presence of unlabelled oxytocin in excess. Comparable results were obtained using tritiated or iodinated ligand. Labelling was most intense in the substantia nigra pars compacta, the substantiae gelatinosae of the caudal spinal trigeminal nucleus and of the dorsal horn of the upper spinal cord, as well as in the medio-dorsal region of the nucleus of the solitary tract. Binding was also detected in the rest of the nucleus of the solitary tract and in other areas, including the oral and interpolar parts of the spinal trigeminal nucleus, the hypoglossal nucleus and the area postrema. Presence of oxytocin binding sites in regions concerned with sensory, autonomic and motor processing suggests that oxytocin could act as a neurotransmitter of neuromodulator in the human central nervous system.  相似文献   
128.
129.
This article reviews the history of sign language (SL) and the rationale for its use in children with profound auditory agnosia due to Landau-Kleffner syndrome (LKS), illustrated by studies of children and adults followed for many years and rare cases from the literature. The reasons that SL was successful and brought some children out of isolation while it could not be implemented in others are discussed. The nowadays earlier recognition and treatment of LKS and better awareness of the crucial need to maintain communication have certainly improved the outcome of affected children. Alternatives to oral language, even for less severe cases, are increasingly accepted. SL can be learned at different ages with a clear benefit, but the ambivalence of the patients and their families with the world and culture of the deaf may sometimes explain its refusal or limited acceptance. There are no data to support the fear that SL learning may delay or prevent oral language recovery in children with LKS. On the contrary, SL may even facilitate this recovery by stimulating functionally connected core language networks and by helping speech therapy and auditory training.  相似文献   
130.

Aims

To assess the effects of a Pilates exercise program compared to conventional pelvic floor muscle training (PFMT) protocol on pelvic floor muscle strength (PFMS) in patients with post‐prostatectomy urinary incontinence.

Methods

Patients were randomized into three treatment groups (G1: Pilates, G2: electrical stimulation combined with PFMT, and G3: control group). Duration of therapy was 10 weeks. Baseline assessment included the 24 h pad‐test and the ICI‐Q questionnaire. PFMS was measured using a manometric perineometry device at baseline and 4 months after radical prostatectomy (RP). The level of significance was P < 0.05.

Results

One hundred twenty three patients were randomized and 104 patients completed the study protocol (G1: n = 34; G2: n = 35; G3: n = 35). Post‐treatment assessment showed statistically significant improvements in maximum strength in G2, increased endurance in G1 and G2, and increment of muscle power in all three groups (P < 0.05). However, there were no significant differences in the mean changes of maximum strength, endurance, and muscle power between groups after treatment (P > 0.05). G1 and G2 achieved a higher number of fully continent patients than G3 (P < 0.05). At the end of treatment, 59% of patients in G1, 54% in G2, and 26% in G3 were continent (no pads/day).

Conclusions

Improvements in PFMS parameters were distinct among active treatment groups versus controls, but did not predict recovery of urinary continence at final assessment. The Pilates method promoted similar outcomes in the proportion of fully continent patients when compared to conventional PFMT 4 months after RP.  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