全文获取类型
收费全文 | 10039篇 |
免费 | 943篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 166篇 |
儿科学 | 413篇 |
妇产科学 | 209篇 |
基础医学 | 1295篇 |
口腔科学 | 129篇 |
临床医学 | 1044篇 |
内科学 | 1761篇 |
皮肤病学 | 369篇 |
神经病学 | 1017篇 |
特种医学 | 493篇 |
外科学 | 1297篇 |
综合类 | 254篇 |
一般理论 | 5篇 |
预防医学 | 1249篇 |
眼科学 | 144篇 |
药学 | 701篇 |
中国医学 | 4篇 |
肿瘤学 | 509篇 |
出版年
2021年 | 105篇 |
2020年 | 68篇 |
2019年 | 112篇 |
2018年 | 132篇 |
2017年 | 128篇 |
2016年 | 98篇 |
2015年 | 125篇 |
2014年 | 197篇 |
2013年 | 305篇 |
2012年 | 332篇 |
2011年 | 366篇 |
2010年 | 232篇 |
2009年 | 232篇 |
2008年 | 400篇 |
2007年 | 528篇 |
2006年 | 431篇 |
2005年 | 379篇 |
2004年 | 375篇 |
2003年 | 363篇 |
2002年 | 358篇 |
2001年 | 349篇 |
2000年 | 412篇 |
1999年 | 328篇 |
1998年 | 207篇 |
1997年 | 159篇 |
1996年 | 173篇 |
1995年 | 162篇 |
1994年 | 137篇 |
1993年 | 140篇 |
1992年 | 278篇 |
1991年 | 232篇 |
1990年 | 266篇 |
1989年 | 244篇 |
1988年 | 228篇 |
1987年 | 225篇 |
1986年 | 186篇 |
1985年 | 225篇 |
1984年 | 143篇 |
1983年 | 112篇 |
1982年 | 117篇 |
1981年 | 86篇 |
1980年 | 89篇 |
1979年 | 115篇 |
1978年 | 105篇 |
1977年 | 86篇 |
1976年 | 93篇 |
1975年 | 85篇 |
1974年 | 93篇 |
1973年 | 93篇 |
1972年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Short-term hyperglycemia depresses immunity through nonenzymatic glycosylation of circulating immunoglobulin 总被引:7,自引:0,他引:7
Hyperglycemia accompanies a myriad of clinical conditions and causes an acceleration in the nonenzymatic glycosylation (NEG) of proteins. Since many proteins lose function when glycosylated, we assessed the effect of hyperglycemia on the function of immunoglobulin G. Twenty newborn Sprague-Dawley rats underwent splenectomy and 20, splenic mobilization alone. After 3 weeks, all animals received an intraperitoneal injection of Streptococcus pneumoniae. Twelve hours later, ten animals from each group received either control (CIG) or glycosylated (GIG) human immunoglobulin (0.3 gm/kg) intraperitoneally. Asplenic animals receiving GIG lived 28.5 hours vs. 49.6 hours for those receiving CIG (p less than 0.0001). Animals with spleens receiving GIG lived 48.2 hours vs. 51.7 hours for those receiving CIG (p = 0.03). Short-term glycosylation of immunoglobulin causes its inactivation. This may contribute to the increased risk of infection noted in hyperglycemic animals. 相似文献
12.
CT appearance of cervical lipoblastoma 总被引:1,自引:0,他引:1
W C Black J W Burke P S Feldman C M Johnson S Swanson 《Journal of computer assisted tomography》1986,10(4):696-698
We describe a case of lipoblastoma causing respiratory symptoms in an infant, where CT was useful in establishing the diagnosis and demonstrating the extent of involvement so that complete surgical resection could be planned. 相似文献
13.
A case of lymphocytic adenohypophysitis in a postpartum woman who became symptomatic during her 8th month of pregnancy is presented. The clinical presentation, endocrine findings, pathological findings, and operative management are discussed. Transient hypopituitarism is documented. Unlike most previously published cases, this woman had complete recovery of anterior pituitary function. 相似文献
14.
15.
Dorit Naot Usha Bava Brya Matthews Karen E Callon Gregory D Gamble Michael Black Sarah Song Rocco P Pitto Tim Cundy Jill Cornish Ian R Reid 《Journal of bone and mineral research》2007,22(2):298-309
Paget's disease is a focal condition of bone. To study changes in cells within pagetic lesions, we cultured osteoblasts and stromal cells from 22 patients and compared gene expression in these cells to cells from healthy bone. We identified several differentially regulated genes, and we suggest that these changes could lead to the formation of the lesions. INTRODUCTION: Paget's disease is a focal condition of bone of unknown cause. Although it is regarded as primarily an osteoclast disorder, the tight coupling of the activity of osteoclasts and osteoblasts suggests that the osteoblast could play a key role in its pathogenesis. The aim of the study was to identify possible changes in pagetic osteoblasts and stromal cells that might contribute to the development of pagetic lesions. MATERIALS AND METHODS: Candidate genes were identified based on known bone cell regulators, supplemented with microarray analysis. Gene expression was determined by real-time PCR in primary cultures of osteoblasts and bone marrow stromal cells from pagetic patients and control subjects. Concentrations of secreted proteins were determined by ELISA. RESULTS: Dickkopf1 mRNA and protein levels were increased in both pagetic osteoblast and stromal cell cultures, and interleukin (IL)-1 and IL-6 were overexpressed in pagetic osteoblasts. These changes parallel recent findings in myeloma bone disease, which shares some clinical similarities with Paget's disease. Alkaline phosphatase was overexpressed, and bone sialoprotein and osteocalcin were underexpressed in pagetic osteoblasts, consistent with their circulating levels in pagetic patients. It is hypothesized that overexpression of Dickkopf1, IL-1, and IL-6 would result in stimulation of osteoclast proliferation and inhibition of osteoblast growth, leading to the development of the characteristic lytic bone lesions. By stimulating osteoblast differentiation, Dickkopf1 and IL-6 may also promote mineralization, leading to the conversion of lytic lesions to sclerotic. CONCLUSIONS: These findings suggest that dysregulated gene expression in pagetic osteoblasts could cause the changes in bone cell number and function characteristic of Paget's disease. 相似文献
16.
N Black 《Journal of public health medicine》1992,14(4):361-366
Evaluative research and audit are distinct activities with different goals. However, they are interrelated in four ways: research provides a basis for defining good-quality care for audit purposes; audit can provide high-quality data for nonexperimental evaluative research; research into the effectiveness and cost-effectiveness of audit is needed to establish the value of different interventions; and, in common with other research areas, evaluative research needs to be audited to ensure high-quality work is performed. Recognition of the unique and interrelated roles of research and audit will be of benefit to both endeavours. 相似文献
17.
To determine if leukotrienes are important mediators of vascular permeability in brain tumors, the effect of 5-lipoxygenase inhibitors on blood-tumor barrier permeability in rats harboring HK Walker 256 brain tumors was examined using quantitative autoradiography with alpha-14C-aminoisobutyric acid. The 5-lipoxygenase enzyme converts arachidonic acid to leukotrienes. Three 5-lipoxygenase inhibitors were utilized: BW755C, nordihydroguaiaretic acid, and AA-861. All three 5-lipoxygenase inhibitors significantly decreased vascular permeability both within the tumors and in brain adjacent to tumor. This suggests that capillary permeability in and adjacent to tumors is influenced by endogenous leukotrienes and that leukotrienes play an important role in brain tumor edema. 相似文献
18.
19.
The effect of oral premedication was investigated in a double-blind, randomised trial in 85 children undergoing tonsillectomy and/or adenoidectomy. Orally administered midazolam 0.5 mg.kg−1 given 30 min pre-operatively was compared with trimeprazine 2 mg.kg−1 given 90 min pre-operatively and a placebo preparation. Compliance, sedation and ease of induction were assessed as were the duration and quality of recovery. Following premedication with midazolam none of the patients was anxious, crying or distressed on leaving the ward, compared with 2/28 in the trimeprazine group and 5/28 in the placebo group (p =0.0007). More patients were calm and quiet on arrival in the anaesthetic room following midazolam than following trimeprazine, with both premedicant agents comparing favourably with placebo. There was no significant difference between the three groups in the time to recovery or the sedation score on discharge to the ward. Midazolam is a safe and effective oral premedicant for children. 相似文献
20.
J Estrada-Aguilar H Greenberg A Walling K Schroer T Black S Morse E Hvizdala 《Cancer》1992,69(5):1137-1145
Five patients, ages 12 to 20 years, with nonresectable primary (Patients 2, 3, and 5) and metastatic (Patients 1 and 4) pelvic osteosarcomas were treated with intraarterial cisplatin and concurrent radiation therapy from 1983 to 1987. Long-term local tumor control was achieved in all five patients. Patients 1 and 3 are alive with no evidence of local recurrence or metastatic disease at 77 and 56 months of follow-up, respectively, since diagnosis of the pelvic tumor. Patients 2, 4, and 5 died of metastatic lung disease at 25, 39, and 12 months, respectively, after diagnosis of the pelvic tumor. Patient 4 had no clinical or radiologic evidence of local recurrence. Control of tumor growth in patients with pelvic osteosarcomas can be achieved with regional chemotherapy and concurrent radiation therapy. These patients also should receive adjuvant intensive systemic chemotherapy to increase the probability of eliminating potential subclinical metastatic disease. 相似文献