全文获取类型
收费全文 | 185215篇 |
免费 | 14076篇 |
国内免费 | 5190篇 |
专业分类
耳鼻咽喉 | 1385篇 |
儿科学 | 3409篇 |
妇产科学 | 1557篇 |
基础医学 | 25268篇 |
口腔科学 | 4015篇 |
临床医学 | 18520篇 |
内科学 | 22465篇 |
皮肤病学 | 1577篇 |
神经病学 | 9795篇 |
特种医学 | 10806篇 |
外国民族医学 | 33篇 |
外科学 | 15122篇 |
综合类 | 30991篇 |
现状与发展 | 12篇 |
一般理论 | 25篇 |
预防医学 | 12209篇 |
眼科学 | 4326篇 |
药学 | 18253篇 |
53篇 | |
中国医学 | 8301篇 |
肿瘤学 | 16359篇 |
出版年
2024年 | 284篇 |
2023年 | 1995篇 |
2022年 | 4283篇 |
2021年 | 6369篇 |
2020年 | 5688篇 |
2019年 | 5751篇 |
2018年 | 5782篇 |
2017年 | 5839篇 |
2016年 | 5961篇 |
2015年 | 5867篇 |
2014年 | 9788篇 |
2013年 | 10430篇 |
2012年 | 8964篇 |
2011年 | 10545篇 |
2010年 | 9217篇 |
2009年 | 9321篇 |
2008年 | 9156篇 |
2007年 | 10232篇 |
2006年 | 9317篇 |
2005年 | 9060篇 |
2004年 | 7849篇 |
2003年 | 7067篇 |
2002年 | 5440篇 |
2001年 | 5155篇 |
2000年 | 4263篇 |
1999年 | 3851篇 |
1998年 | 2809篇 |
1997年 | 2465篇 |
1996年 | 2492篇 |
1995年 | 2413篇 |
1994年 | 2148篇 |
1993年 | 1851篇 |
1992年 | 1610篇 |
1991年 | 1390篇 |
1990年 | 1150篇 |
1989年 | 1091篇 |
1988年 | 1017篇 |
1987年 | 802篇 |
1986年 | 602篇 |
1985年 | 738篇 |
1984年 | 748篇 |
1983年 | 444篇 |
1982年 | 583篇 |
1981年 | 508篇 |
1980年 | 424篇 |
1979年 | 346篇 |
1978年 | 273篇 |
1977年 | 222篇 |
1976年 | 240篇 |
1975年 | 149篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
Summary: As curriculum planners in general medicine residency training programmes we were concerned about house officers' anecdotal reports that hospital work requirements often overshadow individual learning goals. After each of five rotations, we asked residents to identify the educational 'usefulness' of certain rotation components which can be included in three categories; team members, work-related activities and educational events. Of 165 surveys distributed, 127 (77%) were returned. Data were analysed by residency year and by all years combined. The mean overall perception of learning was 3.9 out of a possible 5 points suggesting that residents do find some learning value. Results suggest that different residency years vary as to the significance of specific educational components. The importance of faculty/resident relationships to residents' perceptions of learning value was highlighted in particular. 相似文献
982.
乳腺癌患者血中角蛋白mRNA基因的表达 总被引:1,自引:0,他引:1
目的 分析乳腺癌患者外周血液中角蛋白(CK19)mRNA基因的表达。方法 取20例经病理证实的乳腺癌患者外周血,用Tirizol法提取总RNA,然后进行RT-PCR荧光定量检测,并与正常人群进行对照。结果 正常人群外周血中无CK19表达,20例乳腺癌中有6例阳性表达,总阳性率为29.65%,其中单纯癌阳性率为30.7%(4/13),浸润性导管癌阳性率为28.6%(2/7)。结论 CK19可作为检测外周血循环癌细胞的标志物。 相似文献
983.
泌尿生殖道炎的病原检查研究 总被引:1,自引:0,他引:1
目的 探讨泌尿生殖道炎多种病原学检查的意义。 方法 沙眼衣原体 (CT)抗原检查采用金标法 ,解脲支原体 (UU)和人型支原体 (MH)的检查采用培养法 ,奈瑟淋球菌 (NG)的检查采用革兰氏染色法。 结果 10 0例被检者中 ,一种病原体阳性率 35 % ,两种或两种以上病原体阳性率 2 9% ,总阳性率达 6 4 % ,一种和多种病原体阳性率之间差异无显著性 (χ2 =0 .82 7,P>0 .0 5 ) ;CT检出率为 16 % ,UU检出率为 39% ,MH检出率为 18% ,NG检出率为 30 %。 结论 泌尿生殖道炎患者解脲支原体和淋球菌的感染率较高 ,可同时由多种病原感染引起 ;对于此类患者有必要同时进行多种病原检查 相似文献
984.
应用ATL-ultramark超6型彩色多普勒超声诊断仪诊断扩张型心肌病100例,并与性别、年龄相应的正常人对比分析。结果:除扩张型心肌病各组室间隔及左室后壁舒张期厚度与相应正常对照组相比无显著性差异(P>0.05)外,其左室舒张内径及收缩内径、左房内径明显大于正常对照组(P<0.01),左室射血分数及左室内径缩短分数较正常对照组明显降低(P<0.01),并见心腔内血流速度缓慢,颜色变淡。另在77例病人中探及40例瓣膜返流。提示该诊断方法对扩张型心肌病具有直观、简便、准确、迅速的优点,为本病的诊断及鉴别诊断提供了良好的手段。 相似文献
985.
杀菌性通透性增强蛋白对失血性休克的保护作用及其机理 总被引:2,自引:0,他引:2
分别在失血和复苏开始即刻iv杀菌性/通透性增强蛋白(BPI)1.5和3.5mgkg-1,观察BPI对大鼠失血性休克转归的影响.结果显示,BPI治疗能明显改善失血性休克大鼠肝肾功能,提高休克动物存活率(BPI组81%vs休克对照组44%,P<0.05),BPI组大鼠复苏后与休克前的血浆内毒素(0.20±0.04vs0.24±0.05kUL-1)水平无明显变化,血浆肿瘤坏死因子α和白介素6水平较休克前明显升高,但均显著低于休克对照组.提示BPI对失血性休克大鼠具有一定的保护作用,其机理可能与BPI拮抗休克时内源性内毒素活性,抑制细胞因子反应有关. 相似文献
986.
Monique M. Cherrier Gary W. Small Scott Komo Asenath La Rue 《Psychiatry Research: Neuroimaging》1997,76(2-3):67-74
People undergoing medical procedures sometimes experience feelings that may influence the results. In this study, we explore the relationship between changes in mood state self-ratings and cerebral glucose metabolism during positron emission tomography (PET) in persons with age-associated memory impairment (mean age 59.4±9.8 years). Brain regions of interest involved in both mood and memory were examined. Mood ratings of increased boredom correlated significantly with mesial temporal and parietal asymmetry and decreased parietal metabolism. Mood ratings of increased fatigue correlated with basal ganglia asymmetry and the right basal ganglia and left mesial temporal metabolism. These findings suggest that subjective mood state changes during PET may influence metabolism in brain regions implicated in emotion and memory function in people with age-related memory complaints. 相似文献
987.
应用戊二醛、甲醛甲酚消毒感染根管各80例,观察其细菌学培养情况,结果表明戊二醛消毒根管后细菌培养阳性率4%,甲醛甲酚消毒根管后细菌培养阳性率为18%,说明戊二醛对感染根管的消毒作用显著优于甲醛甲酚消毒剂。 相似文献
988.
Csar O. García A. Kanbour-Shakir Hua Tang Jos F. Molina Luis R. Espinoza Azzudin E. Gharavi 《American journal of reproductive immunology (New York, N.Y. : 1989)》1997,37(1):118-124
PROBLEM: Immunization with β2-glycoprotein I (β2GPI) induces antiphospholipid antibodies (aPL) in normal mice and rabbits. Recently we reported early onset of autoimmunity in MRL/++ mice following immunization with β2GPI. There is a close association between aPL with thrombosis, recurrent fetal loss, and intrauterine growth retardation. In this study we evaluated the effect of β2GPI-induced aPL on pregnancy outcomes in an inbred strain of mice (PL/J). METHOD: Three groups of seven-week-old female PL/J mice (12 per group) were studied. Group A was immunized with β2GPI and group B with ovalbumin; group C was not immunized. After two booster injections, the mice were tested for aPL, anti-DNA by ELISA, and for ANA by indirect immunofluorescence. Platelet count and pregnancy outcomes were studied at the age of 14 weeks. RESULTS: The aPL and anti-DNA levels were higher at 12 and 14 weeks in group A; the optical densities (OD) were 1.72±0.6 and 0.699±0.25 for group A, 0.091 ±0.040 and 0.230±0.47 for group B, and 0.0435±0.003 and 0.119±0.026 for group C (comparing group A with groups B and C combined, P<0.001). ANA titers rose in groups A and B by age, but they were significantly higher at 14 weeks in group A. The mean titers were 1/286, 1/90, and 1/16 for A, B, and C, respectively (P<0.001). The platelet counts were not significantly different among the three groups. The litter size was significantly smaller in group A, as evidenced by the numbers of viable fetuses among the mice that became pregnant in each group: 0.75, 2.45, and 5.5 in groups A, B, and C, respectively. Seven pregnant mice in group A had complete resorption, seven pregnant mice in group B showed focal (partial) resorption areas, and only one mouse in group C had complete resorption of the embryos, as shown by histopathological studies, although the fecundity rate was similar in the three groups. CONCLUSION: Our data suggest a pathogenic role for β2GPI-induced aPL in the development of experimental models of APS in PL/J mice. 相似文献
989.
采用气相色谱-质谱联用方法,对白桦树皮挥发油进行了研究,共鉴定出29种化合物,主要成分为2-氧代丙酸(53.54%)。 相似文献
990.
本文比较了11例眼球异物CT与X线影像,并经手术摘出异物证实,CT眼球异物检出及定位准确性均优于X线,尤其对球壁异物的定位,而且能显示断层眼球壁轮廓,具有直观效果,CT异物影像比异物明显扩大,应警惕CT伪影可能使球壁异物定位发生误差,CT目前尚不能完全取代眼球异物常规X线检查。 相似文献