全文获取类型
收费全文 | 812篇 |
免费 | 76篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 3篇 |
妇产科学 | 3篇 |
基础医学 | 97篇 |
口腔科学 | 1篇 |
临床医学 | 84篇 |
内科学 | 126篇 |
皮肤病学 | 4篇 |
神经病学 | 19篇 |
特种医学 | 36篇 |
外科学 | 96篇 |
综合类 | 139篇 |
现状与发展 | 1篇 |
预防医学 | 59篇 |
眼科学 | 9篇 |
药学 | 87篇 |
2篇 | |
中国医学 | 63篇 |
肿瘤学 | 76篇 |
出版年
2024年 | 7篇 |
2023年 | 15篇 |
2022年 | 49篇 |
2021年 | 49篇 |
2020年 | 50篇 |
2019年 | 30篇 |
2018年 | 26篇 |
2017年 | 21篇 |
2016年 | 24篇 |
2015年 | 37篇 |
2014年 | 51篇 |
2013年 | 34篇 |
2012年 | 56篇 |
2011年 | 48篇 |
2010年 | 47篇 |
2009年 | 34篇 |
2008年 | 40篇 |
2007年 | 46篇 |
2006年 | 41篇 |
2005年 | 33篇 |
2004年 | 20篇 |
2003年 | 14篇 |
2002年 | 27篇 |
2001年 | 18篇 |
2000年 | 19篇 |
1999年 | 25篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 14篇 |
1995年 | 11篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有922条查询结果,搜索用时 0 毫秒
71.
Cheng M Fei B Zheng X Chen Y Sun R Wei H Tian Z 《International immunopharmacology》2012,13(1):109-113
A specific and accurate bioassay for determining the biological activity of human interleukin-12 (hIL-12), an important typical Th1 cytokine in both innate and adaptive immunity, is extensively required for biomedical and clinical study. In this paper, we used a new established NK cell line NKG cells as the responder to hIL-12 stimulation by detecting their IFN-γ production. It was found that NKG cells produced high level of IFN-γ when simulated by hIL-12, and the dose-response curve became the best Sigmoid curve (R(2)=0.9977, p<0.0001) when stimulated for 24h. The intra-assay CVs (<10%) and inter-assay CVs (<5%) demonstrated that the bioassay was precise and reproducible. Furthermore, no obvious cross-effects of other cytokines such as IL-2 and IL-18 was observed on the bioassay. Addition of the neutralizing anti-hIL-12 antibody to the bioassay significantly inhibited the IFN-γ production in a dose dependent manner, indicating that the bioactivity was actually mediated by hIL-12. The bioassay by using NKG cells was also suitable for determining the biological activity of recombinant hIL-12 in the form of purified product or culture supernatant by CHO-hIL-12 cell line. In conclusion, a reliable hIL-12 bioassay for determining its biological activity was established by using NKG cells as a responder and measuring their production of IFN-γ. 相似文献
72.
目的观察电针百会、大椎对血管性痴呆模型大鼠认知功能的影响,探讨其作用机制。方法将30只雄性SD大鼠按随机数字表法分为假手术组、模型组和电针组,每组10只。模型组和电针组大鼠采用双侧颈总动脉结扎的方法制备血管性痴呆大鼠模型。造模2周后,电针组电针百会、大椎,连续干预4周。分别于干预前和干预完成后,采用新物体识别行为学测试检测1、24 h新物体偏爱系数;氢质子磁共振波谱(1H-MRS)扫描海马区N-乙酰天冬氨酸(N-acetylaspartate,NAA)/肌酸(creatine,Cr)、胆碱(choline-containing compounds,Cho)/Cr神经代谢物水平;采用PCR法检测caspase-3、Bax mRNA表达,免疫组化检测突触素(synaptophysin,SYN)表达。结果与模型组比较,电针组1 h[(69.85±11.26)%比(50.26±8.85)%]、24 h[(60.85±11.86)%比(43.26±10.25)%]新物体偏爱系数均升高(P<0.01),海马区NAA/Cr[(1.344±0.149)比(0.892±0.178)]水平升高(P<0.01)、Cho/Cr[(0.661±0.142)比(0.902±0.178)]水平降低(P<0.01),海马区caspase-3 mRNA[(1.342±0.041)比(2.437±0.089)]、Bax mRNA[(2.135±0.083)比(4.358±0.137)]水平降低(P<0.01),SYN[(0.577±0.035)比(0.315±0.025)]表达增加(P<0.01)。结论电针百会、大椎可有效改善血管性痴呆模型大鼠的认知功能障碍,可能与改善海马区神经代谢物NAA、Cho含量、抑制神经元凋亡及改善神经元突触功能有关。 相似文献
73.
不同栽植密度和施肥量下党参生物量变化动态及其效应研究 总被引:2,自引:0,他引:2
通过栽植密度和施肥量二因素四水平三重复随机区组试验结果:对茎叶生物量积累最具优势的组合为密度105万株/hm2和施肥量240 kg/hm2,增量为652 mg/d;对单根生物量积累最优组合为密度60万株/hm2和施肥量240 kg/hm2,单根重达14.88 g.本试验结果可为党参种植及田间管理提供参考. 相似文献
74.
广东省涉外乡镇企业职业性噪声危害情况调查分析 总被引:1,自引:0,他引:1
目的 了解广东省涉外乡镇企业职业性噪声危害情况,为防治措施提供科学依据。方法 对1992 ~1996 年进行的《广东省涉外乡镇企业职业危害状况调查》的噪声危害情况资料进行研究分析。结果 在广东省涉外乡镇企业中,接触噪声的工人占接触职业有害因素工人的32-06 % ,噪声作业点超标率为31-32 % ,接触噪声工人的高频损伤和语音损伤总检出率为8-92 % ;在没有得到有效的防护措施的保护情况下,超时间暴露在严重超标的噪声环境,是造成噪声对工人身体危害的主要原因。结论 噪声是广东省涉外乡镇企业主要的职业危害因素之一。禁止落后生产设备的使用,加强“三同时”管理和个人防护措施的落实,提高工人自我保护意识,避免超时工作,是预防涉外乡镇企业职业性噪声危害的主要措施。 相似文献
75.
Yuanqing Zhang Xiang Xiao Xianchang Li Haiming Wei 《Journal of gastroenterology and hepatology》2009,24(8):1457-1462
Background and Aims: Liver injury induced by Concanavalin A (Con A) is often used as a model to study the pathophysiology of immune mediated liver injury. Rapamycin (Rapa) is an effective immunosuppressant widely used for preventing immune activation and transplant rejection. However, the effect of Rapa on liver injury caused by Con A has not been carefully examined. In the present study, we examined the effect of Rapa on liver injury caused by Con A.
Methods: Mice received intraperitoneal Rapa injection before Con A intravenous administration. The liver injury was examined by measuring serum transaminase and pathology, and the level of cytokines was detected by enzyme linked immunosorbent assay (ELISA).
Results: In the present study, we examined the effect of Rapa on liver injury after Con A injection in mice. We found that the treatment of mice with Rapa protected the liver from Con A-induced injury. Pretreatment with Rapa dramatically ameliorated Con A-induced mortality. This protection was associated with reduced transaminase levels in the blood and further confirmed by liver histology. ELISA showed that Rapa suppressed pro-inflammatory cytokines IFN-γ and TNF-α production as compared with the untreated controls. Furthermore, intrahepatic lymphocyte proliferation was significantly inhibited.
Conclusion: These findings suggested that Rapa has the therapeutic potential for treatment of immune-mediated liver injury in the clinic. 相似文献
Methods: Mice received intraperitoneal Rapa injection before Con A intravenous administration. The liver injury was examined by measuring serum transaminase and pathology, and the level of cytokines was detected by enzyme linked immunosorbent assay (ELISA).
Results: In the present study, we examined the effect of Rapa on liver injury after Con A injection in mice. We found that the treatment of mice with Rapa protected the liver from Con A-induced injury. Pretreatment with Rapa dramatically ameliorated Con A-induced mortality. This protection was associated with reduced transaminase levels in the blood and further confirmed by liver histology. ELISA showed that Rapa suppressed pro-inflammatory cytokines IFN-γ and TNF-α production as compared with the untreated controls. Furthermore, intrahepatic lymphocyte proliferation was significantly inhibited.
Conclusion: These findings suggested that Rapa has the therapeutic potential for treatment of immune-mediated liver injury in the clinic. 相似文献
76.
Xiaoxia Yang Jianchao Bian Xin Wang Haiming Wang Yongping Liu Shuzhen Wang Zhichun Mu Xinluan Li 《中国神经再生研究》2008,3(9):985-990
BACKGROUND: Zinc (Zn) has been shown to greatly influence brain development. Zn supplements may reduce injury to cell membranes of the thyroid gland due to iodine deficiency. OBJECTIVE: To establish an iodine deficiency rat model using low-iodine food, which was supplemented with compound Zn and Zn gluconate, to observe the effects of Zn on brain development, as well as pituitary gland and thyroid gland function in iodine-deficient rats. DESIGN, TIME AND SETTING: Randomized grouping study of neural development was performed in the central laboratory of Shandong Institute for Prevention and Treatment of Endemic Disease from 1998 to 1999. MATERIALS: A total of 270 Wistar, female rats, one month after weaning, were used in this study, including 150 pregnant and 120 neonatal rats. Rats were randomly divided into six groups: normal control, model, iodine, compound Zn, iodine and compound Zn, and zinc gluconate. Each group contained 25 pregnant rats and 20 neonatal rats. METHODS: The pregnant rats and 20 neonatal rats, and well as the normal group, were fed standard chow and allowed free access to tap water (containing 5 u g/L iodine and 1 mg/L Zn). The remaining five groups were fed low-iodine chow. However, the model group received distilled water, the iodine group received potassium-iodide distilled water (containing 300 u g/L iodine), the compound Zn group received distilled water and intragastrically administrated 10 mL/kg compound Zn solution, once per day, the iodine and compound Zn group received distilled water with 300 u g/L iodine and intragastrically administrated 10 mL/kg compound Zn solution, once per day. All treatments lasted 90 days. MAIN OUTCOME MEASURES: All pregnant rats were sacrificed on the day 21 of pregnancy. Body mass number and rate of fetal absorption, as well as fetal death and malformation, were determined. Thyroid and pituitary gland weights were measured, as well as serum levels of thyroid hormone, gonadotropin, and sex hormones. In the experimental study of ne 相似文献
77.
检测端粒酶活性的PCR—ELISA方法的建立 总被引:3,自引:0,他引:3
建立一种更为敏感,特异的端粒酶检测方法。方法将分子生物学和免疫学方法有机地结合起来,建立PCR-ELISA方法并检测多种肿瘤细胞株和部分组织中端粒酶活性。结论PCR-ELISA方法检测端粒酶活性是一种简便,快速,无放射性污染的方法,适用于肿瘤早期诊断和普查。 相似文献
78.
StudyonEffectofAstragalusonLeftVentricularCollagenRemodelingafterMyocardialInfarctioninRats 下载免费PDF全文
Objective: To study the effect of Astragalus (As) on left ventricular collagen remodeling after myocardial infarction in rats.Methods: Myocardial collagen (MC) and ratio of myocardial collagen type I and M in rat models of myocardial infarction treated with
Astragalus injection were determined and compared with those in sham operated rats and in captopril(CAP) treated rats.Results: MC and ratio of MC I /IE of non-in-farcted region in the myocardial infarction rats was higher than that in the sham group.
Both AS and CAP could restrain the ascending trend of these parameters.Conclusion: Astragalus is effective in lowering the elevation of MC after infarction and changing the MC I /H ratio, therefore, is beneficial
to improve the systolic and diastolic function of left ventricle after acute myocardial infarction. 相似文献
79.
80.
超敏C-反应蛋白与血管内皮功能不全 总被引:1,自引:1,他引:1
目的:探讨超敏C-反应蛋白(high-sensitivity C-reactive protein,hsCRP)与血管内皮功能不全的关系。方法:随机选取复旦大学附属金山医院心血管内科住院病人69例,行hsCRP检测,浓度≥3mg/L为hsCRP升高组;浓度<3mg/L为 hsCRP正常组。同时用高分辨率彩色多普勒超声测定每个病例血流介导的肱动脉扩张(flow mediated dilation,FMD),肱动脉内径变化率被用来评估血管内皮功能。结果:比较hsCRP升高组与正常组FMD变化率,结果显示hsCRP升高组 FMD变化率(1.4±1.3)低于正常组(4.0±3.9),具有显著差异(P<0.05)。结论:炎症与血管内皮功能不全相关。 相似文献