全文获取类型
收费全文 | 183105篇 |
免费 | 17756篇 |
国内免费 | 12579篇 |
专业分类
耳鼻咽喉 | 1909篇 |
儿科学 | 2460篇 |
妇产科学 | 1654篇 |
基础医学 | 16962篇 |
口腔科学 | 3353篇 |
临床医学 | 22443篇 |
内科学 | 22647篇 |
皮肤病学 | 2090篇 |
神经病学 | 7258篇 |
特种医学 | 6814篇 |
外国民族医学 | 78篇 |
外科学 | 18896篇 |
综合类 | 39467篇 |
现状与发展 | 50篇 |
一般理论 | 11篇 |
预防医学 | 15545篇 |
眼科学 | 4202篇 |
药学 | 19612篇 |
221篇 | |
中国医学 | 14034篇 |
肿瘤学 | 13734篇 |
出版年
2024年 | 711篇 |
2023年 | 2631篇 |
2022年 | 6751篇 |
2021年 | 8677篇 |
2020年 | 6997篇 |
2019年 | 5346篇 |
2018年 | 5748篇 |
2017年 | 5812篇 |
2016年 | 5457篇 |
2015年 | 8652篇 |
2014年 | 10489篇 |
2013年 | 10917篇 |
2012年 | 15757篇 |
2011年 | 16859篇 |
2010年 | 12683篇 |
2009年 | 10633篇 |
2008年 | 12010篇 |
2007年 | 11421篇 |
2006年 | 10800篇 |
2005年 | 9253篇 |
2004年 | 6593篇 |
2003年 | 6282篇 |
2002年 | 5225篇 |
2001年 | 3947篇 |
2000年 | 3048篇 |
1999年 | 2351篇 |
1998年 | 1371篇 |
1997年 | 1281篇 |
1996年 | 1010篇 |
1995年 | 894篇 |
1994年 | 721篇 |
1993年 | 441篇 |
1992年 | 478篇 |
1991年 | 386篇 |
1990年 | 345篇 |
1989年 | 251篇 |
1988年 | 228篇 |
1987年 | 229篇 |
1986年 | 164篇 |
1985年 | 131篇 |
1984年 | 59篇 |
1983年 | 49篇 |
1982年 | 34篇 |
1981年 | 38篇 |
1980年 | 21篇 |
1979年 | 43篇 |
1977年 | 19篇 |
1976年 | 17篇 |
1974年 | 22篇 |
1973年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
71.
目的:探讨局部应用白细胞介素-12(IL-12)对于小鼠皮下肿瘤的治疗作用.方法:小鼠右侧腹部皮下注射2x105 个Panc-02细胞建立皮下肿瘤模型.皮下肿瘤被检测24d,通过测量的皮下肿瘤的两个直径以计算出肿瘤大小(mm2).分为IL-12治疗组和对照组,每组6只小鼠.从第3~7天,IL-2治疗组,每天在肿瘤周围注射0.1 μg IL-12,对照组同时同部注射同量平衡盐水.结果:与对照组相比,IL-12治疗组从第7天开始Panc-02肿瘤的生长出现受到抑制.第10天,IL-12治疗组[(13.8±8.7) mm2]与对照组[(36.4±8.5) mm2],(P<0.05)之间的差异有统计学意义(P<0.05).第24天,两组之间的差异更加明显[(66.5±50.4) mm2 VS (264.4±46.4 )mm2, P<0.01].结论:肿瘤周围注射IL-12明显抑制Panc-02皮下肿瘤的生长,为应用于临床肿瘤治疗提供可能性. 相似文献
72.
QIN Jian LIU Hong-jian DENG Wei WU Guo-zhen CHEN Shu-qing JING Ming-hua 《中国生物医学工程学报(英文版)》2005,14(3):114-119
Based on the fuzzy characteristic of the pulse state and syndromes differentiation thinking mode of TCM, an information fusing recognition method of pulse states based on SFNN (Stochastic Fuzzy Neural Network) is presented in this paper. With the learning ability in parameters and structure, SFNN fuses the measurement information of three pulse-state sensors distributed in Cun, Guan, and Chi location of body for the pulse state recognition. The experimental results show that the percentage of correct recognition with new method is higher than that by single-data recognition one, with fewer off-line train numbers. 相似文献
73.
The disaccharide trehalose is a key element involved in anhydrobiosis (the capability of surviving almost complete dehydration) in many organisms. Its presence also confers resistance to desiccation and high osmolarity in bacterial and human cells by protecting proteins and membranes from denaturation. The present study used a novel murine dry eye model induced by controlled low-humidity air velocity to determine whether topically applied trehalose could heal ocular surface epithelial disorders caused by ocular surface desiccation. In addition, the efficacy of 87.6 mM trehalose eyedrops was compared with that of 20% serum, the efficacy of which has been well documented. Mice ocular surface epithelial disorders were induced by exposure of murine eyes to continuous controlled low-humidity air velocity in an intelligently controlled environmental system (ICES) for 21 days, which accelerated the tear evaporation. The mice were then randomized into three groups: the control group received PBS (0.01M) treatment; a second group received 87.6 mM trehalose eyedrops treatment; and the third group received mice serum eyedrops treatment. Each treatment was administered as a 10 μl dose every 6 h for 14 days. The resultant changes in corneal barrier function and histopathologic examination of cornea and conjunctiva were analyzed and the level of apoptosis on the ocular surface was assessed using active caspase-3. After 14 days of treatment, the corneal fluorescein staining area, the ruffling and desquamating cells on the apical corneal epithelium, as well as the apoptotic cells on ocular surface epithelium had significantly reduced in eyes treated with trehalose compared with those treated with serum and PBS. In contrast, after 14 days of treatment, improvements in the thickness of the corneal epithelium, the squamous metaplasia in conjunctival epithelium and the number of goblet cells of the conjunctiva were less marked in eyes treated with trehalose compared with serum. These results demonstrated that trehalose could improve the appearance of ocular surface epithelial disorders due to desiccation through suppression of apoptosis. Trehalose produces some of the same responses as serum upon topical application and can maintain corneal health. 相似文献
74.
白藜芦醇抑制胶质瘤细胞生长与诱导细胞凋亡实验研究 总被引:6,自引:3,他引:3
目的探讨白藜芦醇(Res)对脑胶质瘤细胞(C6细胞株)和正常成纤维细胞(3T3细胞株)体外增殖的影响,进而观察Res诱导C6和3T3细胞系的凋亡作用.方法用不同浓度的Res处理C6和3T3细胞,以四甲基偶氮唑蓝(MTT)比色法检测Res对C6和3T3细胞的增殖作用,通过HE染色、扫描电子显微镜(SEM)、原位末端标记法(TUNEL)和流式细胞仪Annexin Ⅴ荧光染色,观察细胞的形态学结构改变,并定量检测细胞凋亡.结果 Res抑制了C6细胞的生长与增殖( P < 0.01 ),呈浓度依赖性反应;Res能明显诱导C6细胞凋亡,经210 μmol/L、120 μmol/L Res处理24 h后及对照组的C6细胞,其凋亡率分别为29.7%、14.6%及2.1%;相应的3T3细胞凋亡率分别为4.3%、3.5%、2.6%. 结论 Res能通过诱导C6细胞凋亡而抑制其生长与增殖,但对3T3细胞无此作用.本研究为临床应用Res治疗脑胶质细胞瘤提供了实验依据. 相似文献
75.
76.
本文将对呼吸机以下两种常见故障进行简要分析:①呼吸机在抢救病人过程中出现自动切断电源②呼吸机气道口湿度报警。 相似文献
77.
Elizabeth R Seaquist Wei Chen Luke E Benedict Kamil Ugurbil Jae-Hwan Kwag Xiao-Hong Zhu Charles A Nelson 《Journal of cerebral blood flow and metabolism》2007,27(1):154-160
Functional magnetic resonance imaging (fMRI) based on blood oxygen level-dependent (BOLD) contrast has become an invaluable tool in the assessment of in vivo neuronal activation. Quantification of the BOLD response is determined by the hemodynamic and metabolic changes that occur in response to brain stimulation. However, these changes may vary by changes in insulin, a hormone known to be vasoactive in some tissues. To determine if insulin has an effect on fMRI, we measured the BOLD response to a visual stimulus in five normal volunteers in which insulin was first suppressed and then brought to a high physiological concentration. In addition, we also examined the effect of insulin on activation of the visual cortex as measured by the visual-evoked potential (VEP). We found that the BOLD response measured in the presence of insulin (serum insulin=236+/-29 pmol/L) was significantly lower (P<0.001) than that measured in its absence (serum insulin=8+/-2 pmol/L). Insulin was without effect on P100 amplitude or latency acquired in the presence or absence of insulin in 28 subjects using the same stimulus as that used for the fMRI experiments. Our observations suggest that insulin may have effects on cerebral blood flow and/or metabolism that affect the BOLD signal that are independent of its effects on neuronal activation identified by event related potentials (ERP). These findings highlight the complexity that must be considered when interpreting differences in fMRI responses between groups of subjects that differ in insulin concentration and/or insulin sensitivity. 相似文献
78.
目的 评价1.5T和3.0T两种不同的磁场强度对膝关节影像质量的影响.方法 采用同一厂家、同一系列、不同磁场强度的两种成像设备,对16位健康自愿者在1.5T和3.0T两种不同的磁场强度下,分别进行膝关节成像,序列使用相同的参数,不校正磁场强度的变化对TR的影响.分别测量半月板、肌肉、脂肪和骨骼的信噪比、对比噪声比和相对对比度,进行定量分析.结果 3.0T条件下膝关节图像的信噪比和对比噪声比明显优于1.5T,差异有统计学意义;3.0T条件下膝关节图像的相对对比度与1.5T比较,没有明显的统计学差异.结论 膝关节图像的信噪比和对比噪声比均随着场强的增加而提高,膝关节图像的相对对比度随场强的变化并不敏感. 相似文献
79.
80.
颞颌关节继发性滑膜炎的临床诊断 总被引:5,自引:0,他引:5
颞颌关节滑膜炎分为原发性和继发性两种,颞颌关节紊乱综合症的滑膜炎为继发性滑膜炎。本文通过对106例颞颌关节紊乱综合症患者的临床检查、关节许氏位以及关节上腔造影的X线检查,同时对42例进行了关节内窥镜检查,在此基础上探讨了继发性滑膜炎的临床诊断标准.作者认为急性滑膜炎主要是以关节疼痛和滑膜血管的改变为主,慢性滑膜炎的临床症状与滑膜组织改变以及关节骨组织的改变均有关系。 相似文献