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   8192篇
  免费   753篇
  国内免费   29篇
耳鼻咽喉   27篇
儿科学   345篇
妇产科学   158篇
基础医学   999篇
口腔科学   245篇
临床医学   909篇
内科学   1732篇
皮肤病学   121篇
神经病学   588篇
特种医学   663篇
外科学   756篇
综合类   132篇
一般理论   4篇
预防医学   852篇
眼科学   189篇
药学   711篇
中国医学   8篇
肿瘤学   535篇
  2022年   40篇
  2021年   129篇
  2020年   80篇
  2019年   107篇
  2018年   123篇
  2017年   85篇
  2016年   108篇
  2015年   156篇
  2014年   183篇
  2013年   283篇
  2012年   322篇
  2011年   307篇
  2010年   254篇
  2009年   205篇
  2008年   325篇
  2007年   336篇
  2006年   330篇
  2005年   341篇
  2004年   336篇
  2003年   298篇
  2002年   302篇
  2001年   277篇
  2000年   266篇
  1999年   228篇
  1998年   227篇
  1997年   203篇
  1996年   197篇
  1995年   156篇
  1994年   135篇
  1993年   144篇
  1992年   178篇
  1991年   179篇
  1990年   145篇
  1989年   187篇
  1988年   159篇
  1987年   162篇
  1986年   151篇
  1985年   150篇
  1984年   107篇
  1983年   113篇
  1982年   91篇
  1981年   73篇
  1980年   72篇
  1979年   67篇
  1978年   69篇
  1977年   47篇
  1976年   66篇
  1975年   58篇
  1974年   38篇
  1972年   37篇
排序方式: 共有8974条查询结果,搜索用时 15 毫秒
1.
2.
3.
The myopathies that can manifest themselves within the lower extremity are reported here and can serve as a guideline for clinicians in the early diagnosis of these disabling conditions. The classification of these disease entities based on signs and symptoms is significant if correlated with the age of the patient at the time of onset, the evolution and course, and the type of familial inheritance. This article can also aid the practitioner in assessing and planning the course of treatment for a particular patient.  相似文献   
4.
Bay K 8644 potentiated and augmented 5-hydroxytryptamine (5-HT)-induced contractions in the rabbit, isolated aorta preparation, as manifested in leftward shift and increase in the asymptote of 5-HT E/[A] (effect vs concentration) curves. The operational model of agonism (Black & Leff, 1983) was used to analyse this interaction and the concomitant effects of irreversible receptor alkylation by phenoxybenzamine. The competitive effects of spiperone in the presence and absence of Bay K 8644 were also examined. From these analyses it is concluded that Bay K 8644 elicits its potentiating effects by increasing the efficacy of 5-HT at the 5-HT2 receptor with no alteration in affinity. This is consistent with the known effect of Bay K 8644 of causing an increase in the functional concentration of plasmalemmal calcium channels coupled to the 5-HT2 receptors in this preparation. The positively co-operative shape of the 5-HT E/[A] curves obtained in the aorta and the quantitative nature of their potentiation by Bay K 8644 indicated that the coupling of 5-HT2 receptor occupancy to intracellular calcium concentration is linear and that the co-operativity resides in the subsequent relation between intracellular calcium and pharmacological effect. Bay K 8644 may serve as a probe for differentiating between the types of calcium channels that transduce 5-HT receptor-mediated effects in different systems. Such information would be useful in the classification of agonist interactions with 5-HT receptors.  相似文献   
5.
6.
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population.  相似文献   
7.
Abstract – This study describes the socio‐economic burden and attitudes of children and their parents following replantation of avulsed incisors. Records of 80 patients with 99 avulsion injuries treated in a teaching hospital clinic from 1988 to 1999 were reviewed. Mean age at time of injury was 10.6 years (range = 6.6–17.7 years). Complete records for a minimum of 1 year were obtained for 43 patients with 60 replanted incisors. Mean treatment procedures provided during the first year included 5.5 diagnostic periapical radiographs, 1.9 occlusal radiographs, 1.3 pulpectomies, and 2.7 pulp medicament applications. The mean estimated treatment cost and direct time (dentist) for first‐year post‐trauma management was $1465 CAD and 7.2 h, respectively. Treatment costs were significantly higher during the first year post‐trauma for patients who had their incisors extracted (P = 0.04), but there was no significant difference in direct treatment time between the two groups (P = 0.19). Twenty‐one patient–parent pairs were surveyed for a number of qualitative factors. Ninety per cent of patients and 86% of parents reported that school and work time was lost. Even after having gone through the painful experience of replantation, the demands of recall, and in some cases, extraction, the majority of patients (67%) and parents (81%) stated that they would have still made the same (replantation) decision. Patient and parent responses were not statistically different (P = 0.453). Almost half the parents stated they would be willing to pay over $2000 CAD to save an incisor. Patients rated retention of an incisor as significantly more important than infraocclusion. This is the first study to quantify the treatment burden of replantation of avulsion injuries exclusively in the pediatric population. This study describes the socio‐economic burden and responsibilities of patient/parent and dentist and their role in informed consent.  相似文献   
8.
9.
10.
L M Rainwater  D M Barrett 《Urology》1990,36(6):522-525
In the case presented, primary lymphoma of the prostate was diagnosed by ultrasonically guided transrectal biopsy. Primary lymphoma of the prostate should be included in the differential diagnosis of a hypoechoic lesion found on ultrasonic evaluation of the prostate in a young adult.  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