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   24142篇
  免费   1826篇
  国内免费   76篇
耳鼻咽喉   290篇
儿科学   660篇
妇产科学   436篇
基础医学   3204篇
口腔科学   340篇
临床医学   2596篇
内科学   5275篇
皮肤病学   331篇
神经病学   2122篇
特种医学   692篇
外科学   3850篇
综合类   442篇
一般理论   25篇
预防医学   2120篇
眼科学   481篇
药学   1717篇
中国医学   39篇
肿瘤学   1424篇
  2023年   225篇
  2022年   475篇
  2021年   992篇
  2020年   506篇
  2019年   737篇
  2018年   870篇
  2017年   571篇
  2016年   647篇
  2015年   725篇
  2014年   972篇
  2013年   1263篇
  2012年   1916篇
  2011年   1936篇
  2010年   1018篇
  2009年   877篇
  2008年   1458篇
  2007年   1417篇
  2006年   1261篇
  2005年   1147篇
  2004年   1046篇
  2003年   937篇
  2002年   867篇
  2001年   302篇
  2000年   239篇
  1999年   247篇
  1998年   149篇
  1997年   149篇
  1996年   143篇
  1995年   114篇
  1994年   92篇
  1993年   93篇
  1992年   177篇
  1991年   160篇
  1990年   139篇
  1989年   130篇
  1988年   140篇
  1987年   143篇
  1986年   130篇
  1985年   123篇
  1984年   108篇
  1983年   99篇
  1982年   94篇
  1981年   107篇
  1980年   90篇
  1979年   98篇
  1978年   79篇
  1977年   59篇
  1976年   75篇
  1974年   68篇
  1972年   60篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real-time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague-Dawley rats, dumbbell-shaped explants were harvested from stainless steel femoral implants after 6-12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L-lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 microM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix.  相似文献   
2.
The authors report a case of massive Trichuris trichiura infection, resulting in severe anaemia and congestive cardiac failure in a 9-year-old Iban boy, who was resistant to the usual oral anthelmintic treatment, but promptly responded to mebendazole retention enema. This patient also had an associated Entamoeba histolytica infection.  相似文献   
3.
4.
BACKGROUND CONTEXT: Multiple lytic lesions of the spine usually represent metastatic or infectious disease processes. PURPOSE: To describe an extremely rare presentation of an uncommon disease process. STUDY DESIGN/SETTING: Case report/university hospital. METHODS: We describe the management of a patient who presented with a pathological fracture of C3 and multiple lytic lesions of the cervical spine. RESULTS: After reconstructive surgery, the final pathological diagnosis was fibrous dysplasia. CONCLUSION: Fibrous dysplasia is rarely seen in the cervical spine and may mimic other pathological processes. The surgical and medical management of spinal fibrous dysplasia is described.  相似文献   
5.
Extracellular single-unit recordings were made in somatosensory cortical barrels of fentanyl-sedated rats. Whiskers were deflected singly or in paired combinations. lontophoretically-applied (−)-baclofen disproportionately reduced weak responses, and phaclofen disproportionately increased them, resulting in more tightly focused or more broadly focused receptive fields, respectively. Both drugs had only minor effects on surround inhibition. In light of previous findings, we conclude that GABAA and GABAB mechanisms both act to enhance spatial contrast, but that the former plays a much greater role in enhancing temporal resolution.  相似文献   
6.
Objective. 1. To identify risk factors associated with psychiatric rehospitalization within six months, using global clinical assessments and demographic information and; 2. To determine if risk factors for a hospital in a rural region are similar to those reported for urban hospitals. Method. The setting was a psychiatric unit within a general hospital. All adult admissions for one year were assigned scores on the North Carolina Functional Assessment Scale (NCFAS) and the Global Assessment of Functioning (GAF) scale. Patients were interviewed six months after discharge to determine if they had been rehospitalized and to assign new NCFAS and GAF scores. Results. Significant risk of rehospitalization was predicted by: 1. NCFAS score >90; 2. history of prior hospitalization; 3. nursing home residence; 4. referral from a small community hospital and; 5. non-compliance with outpatient appointments. Conclusions. Global assessments and demographic information collected during an index admission can generate factors to identify patients at risk for rehospitalization within six months. History of prior admissions and non-compliance with outpatient treatment, reported as risk factors in urban settings, were found also to be risk factors in a rural region.He was formerly Assistant Professor, Center for Health Sciences Statistics, East Carolina University School of Medicine.  相似文献   
7.
8.
Neonatal Sucking Behaviors   总被引:3,自引:0,他引:3  
Neonatal sucking responses or behaviors have been of great interest to researchers and clinicians since the early 1800s. Since 1960, there has been a resurgence of interest in the objective study of sucking behaviors in both the psychological and medical literature. The studies have examined both nutritive and non-nutritive sucking measurements. Sucking behaviors have been studied to understand the development of the feeding mechanism as well as to track neurobehavioral development. The relationship between sucking behaviors and behavioral organization of the newborn are considered, along with a historical perspective of sucking measurements, relevant literature on nutritive sucking, physiologic correlates, differences in breast and bottle feeding patterns, non-nutritive sucking, and factors that modify sucking organization. Implications for nursing practice will be discussed.  相似文献   
9.
10.
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