全文获取类型
收费全文 | 23370篇 |
免费 | 1147篇 |
国内免费 | 1148篇 |
专业分类
耳鼻咽喉 | 242篇 |
儿科学 | 710篇 |
妇产科学 | 412篇 |
基础医学 | 4226篇 |
口腔科学 | 636篇 |
临床医学 | 2292篇 |
内科学 | 4186篇 |
皮肤病学 | 391篇 |
神经病学 | 965篇 |
特种医学 | 441篇 |
外国民族医学 | 4篇 |
外科学 | 1003篇 |
综合类 | 3861篇 |
现状与发展 | 3篇 |
预防医学 | 2085篇 |
眼科学 | 317篇 |
药学 | 1971篇 |
1篇 | |
中国医学 | 497篇 |
肿瘤学 | 1422篇 |
出版年
2024年 | 25篇 |
2023年 | 208篇 |
2022年 | 445篇 |
2021年 | 628篇 |
2020年 | 504篇 |
2019年 | 510篇 |
2018年 | 487篇 |
2017年 | 496篇 |
2016年 | 506篇 |
2015年 | 493篇 |
2014年 | 1041篇 |
2013年 | 1093篇 |
2012年 | 1047篇 |
2011年 | 1322篇 |
2010年 | 1110篇 |
2009年 | 1114篇 |
2008年 | 1214篇 |
2007年 | 1405篇 |
2006年 | 1235篇 |
2005年 | 1307篇 |
2004年 | 1120篇 |
2003年 | 1080篇 |
2002年 | 951篇 |
2001年 | 839篇 |
2000年 | 806篇 |
1999年 | 790篇 |
1998年 | 723篇 |
1997年 | 578篇 |
1996年 | 487篇 |
1995年 | 525篇 |
1994年 | 446篇 |
1993年 | 302篇 |
1992年 | 230篇 |
1991年 | 150篇 |
1990年 | 91篇 |
1989年 | 50篇 |
1988年 | 34篇 |
1987年 | 21篇 |
1986年 | 15篇 |
1985年 | 46篇 |
1984年 | 36篇 |
1983年 | 30篇 |
1982年 | 31篇 |
1981年 | 26篇 |
1980年 | 23篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment. 相似文献
2.
3.
《Vaccine》2019,37(31):4382-4391
Cancer-associated fibroblasts (CAFs), major components of the tumor microenvironment (TME), promote tumor growth and metastasis and inhibit the anti-tumor immune response. We previously constructed a DNA vaccine expressing human FAPα, which is highly expressed by CAFs, to target these cells in the TME, and observed limited anti-tumor effects in the 4T1 breast cancer model. When the treatment time was delayed until tumor nodes formed, the anti-tumor effect of the vaccine completely disappeared. In this study, to improve the safety and efficacy, we constructed a new FAPα-targeted vaccine containing only the extracellular domain of human FAPα with a tissue plasminogen activator signal sequence for enhanced antigen secretion and immunogenicity. The number of CAFs was more effectively reduced by CD8+ T cells induced by the new vaccine. This resulted in decreases in CCL2 and CXCL12 expression, leading to a significant decrease in the ratio of myeloid-derived suppressor cells in the TME. Moreover, when mice were treated after the establishment of tumors, the vaccine could still delay tumor growth. To facilitate the future application of the vaccine in clinical trials, we further optimized the gene codons and reduced the homology between the vaccine and the original sequence, which may be convenient for evaluating the vaccine distribution in the human body. These results indicated that the new FAPα-targeted vaccine expressing an optimized secreted human FAPα induced enhanced anti-tumor activity by reducing the number of FAPα+ CAFs and enhancing the recruitment of effector T cells in the 4T1 tumor model mice. 相似文献
4.
《Nutrition Clinique et Métabolisme》2016,30(1):83-87
Chylous ascitis is a rare cause of ascitis. Most of the time, it results of retroperitoneal lymph node or duct dissection during abdominal or urological surgery; it is rarely due to lymphatic obstruction (neoplasia). Nutritional damage is major and severely impairs prognosis. Malnutrition is due to the necessity to avoid fatty acid in meal to reduce chylous leakage. Diagnosis is based on patient's clinical history and cytologic and biochemical ascitis analyses. Treatment combines the correction of nutritional status and therapy of the causative disease. Oral diet or enteral nutrition with low content of long chain triglyceride, thus enriched in medium chain triglyceride, is the major therapeutic option of chylous ascitis. 相似文献
5.
Although hepatitis E virus (HEV) is the primary cause of enterically transmitted acute hepatitis and jaundice in developing countries, locally acquired HEV infections are increasing in nonendemic countries. As such, HEV is emerging as an underdiagnosed cause of infection. This report describes three clinically variable cases of HEV infection with unusual clinical presentations. These cases highlight the fact that HEV should be considered in the differential diagnosis of patients with unexplained hepatitis (acute or chronic) with or without extrahepatic manifestations. HEV should also be considered in patients with persistently elevated liver enzymes who have not travelled to known HEV-endemic regions. Lack of knowledge among physicians and an absence of standardized diagnostic tests may result in increased morbidity and mortality from HEV infection. 相似文献
6.
7.
目的分析一腓骨肌萎缩症家系的临床表现及不同基因检测方法的特点。方法收集一CMT家系8名成员临床资料,并应用等位基因特异性PCR-双酶切方法及多重连接依赖的探针扩增技术(MLPA)检测PMP22基因突变情况,同时选择60名性别、年龄无明显差异的健康人做为对照组。结果该家系中患病者以行走不稳、跨阈步态,伴有弓形足为主要临床表现。该家系中5名成员经等位基因特异性PCR-双酶切及MLPA方法均检测出PMP22基因重复序列,其中出现临床症状的有4名(Ⅱ3、Ⅱ9、Ⅱ11、Ⅲ7),未出现临床症状但基因检测结果示PMP22基因重复序列的为携带者有1名(Ⅲ5),家系中余3名成员及对照组60名均未见重复序列。结论基因检测在明确CMT诊断中起重要作用,且MLPA法筛查基因时操作更简便、灵敏度更高、特异性更好。 相似文献
8.
9.
10.
目的观察Agilent 2100 Bioanalyzer 芯片分析系统(以下简称Bioanalyzer)在基因差异表达研究中的应用。方法应用限制性显示技术分别从正常和热休克处理后的酿酒酵母细胞中分离出cDNA片段,然后再用Bioanalyzer和传统的琼脂糖凝胶电泳技术对RD-PCR产物进行检测分析。结果Bioanalyzer能更快速、敏感地分离和显示差异表达的基因片段,并且通过对差异片段进行定量比较,发现了数个表达有明显差异的基因片段。结论Bioanalyzer在基因差异表达研究中具有重要的应用价值。 相似文献