全文获取类型
收费全文 | 443篇 |
免费 | 9篇 |
国内免费 | 15篇 |
专业分类
儿科学 | 37篇 |
妇产科学 | 3篇 |
基础医学 | 34篇 |
口腔科学 | 6篇 |
临床医学 | 40篇 |
内科学 | 104篇 |
皮肤病学 | 4篇 |
神经病学 | 7篇 |
特种医学 | 129篇 |
外科学 | 23篇 |
综合类 | 44篇 |
预防医学 | 8篇 |
药学 | 13篇 |
肿瘤学 | 15篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 3篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 23篇 |
1997年 | 39篇 |
1996年 | 45篇 |
1995年 | 23篇 |
1994年 | 25篇 |
1993年 | 25篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 17篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 21篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1968年 | 1篇 |
排序方式: 共有467条查询结果,搜索用时 15 毫秒
1.
2.
3.
Congenital pulmonary atresia with ventricular septal defect: angiographic and surgical correlates 总被引:1,自引:0,他引:1
Of 181 patients with severe congenital pulmonary atresia and ventricular septal defect or "type IV truncus" (an obsolete term), all but 11% had true central pulmonary arteries. These arteries were demonstrable by large serial biplane angiograms using multiple selective injections into collateral vessels, frequent photographic subtraction, and occasional pulmonary vein-wedge angiograms. These techniques are extremely important for accurate diagnosis and in planning corrective or palliative surgery, which was done in 77% of patients with pulmonary arteries. 相似文献
4.
5.
6.
Fas分子与肝细胞凋亡 总被引:7,自引:4,他引:3
近年来细胞分子生物学领域中的两个重要进展,即细胞凋亡概念的提出和Fas分子的分离与鉴定对肝病的研究有重要影响,加深了人们对肝细胞损伤与死亡的认识.1993年Ogasawaraetal[1]进行的Fas单抗毒性实验证实了Fas分子系统在肝细胞凋亡或损伤... 相似文献
7.
Assessing the delivery of neutrophils to tissues in neutropenia 总被引:2,自引:2,他引:2
Studies of neutrophil kinetics in neutropenic individuals, as well as clinical observations of variability in the occurrence of infection among patients with neutropenia, have suggested that blood neutrophil counts may not uniformly reflect the effective delivery of neutrophils to extravascular tissues where the cells perform their principal host defense functions. To evaluate this possibility we developed a sensitive, reproducible method of measuring the extravascular delivery of neutrophils to a normal mucosal site of neutrophil turnover. This method is based upon the quantification of neutrophils recoverable from saline mouth wash specimens. Twenty-five mL specimens, obtained in a controlled manner from neutropenic patients and normal subjects, were centrifuged and the sediments resuspended in 1.0 mL Hank's buffer with 2 micrograms acridine orange, incubated at 37 degrees C for 15 minutes, and then examined in a hemocytometer chamber by fluorescence microscopy. Neutrophils could be clearly distinguished by their characteristic fluorescence and were counted. With this method as few as 1,500 neutrophils were detected reliably in mouth wash specimens. Mucosal neutrophil counts varied less than 10% with repeated sampling of individual subjects over 5-day periods and were consistently greater than 1.3 X 10(5)/specimen in non-neutropenic individuals. Although profound neutropenia was generally reflected by lower than normal oral mucosal neutrophil counts, these counts were significantly higher in individuals with chronic severe neutropenia (blood neutrophils less than 300/mm3) than in patients with acute neutropenia of comparable severity that had developed following chemotherapy. Also, in individuals recovering from profound neutropenia, neutrophils usually reappeared earlier in mouth wash specimens than in blood, and oral mucosal neutrophil counts attained recovery levels more rapidly than did blood counts. This phenomenon was particularly evident in an individual with cyclic neutropenia. Moreover, mucosal neutrophils could occasionally be detected in profoundly neutropenic patients when neutrophils were not present in blood samples. These findings indicate that mucosal neutrophil counts in individuals with neutropenia provide information about the delivery of neutrophils to tissues that may not be apparent from blood neutrophil counts alone. 相似文献
8.
9.
目的:观察内洋地黄素水平在老龄大鼠心肌细胞缺氧复氧损伤中的变化以及地高辛抗血清的保护作用。方法:实验于2005-04/05在皖南医学院病理生理教研室完成。取10只24月龄和10只6月龄雄性普通级SD大鼠,分别制备青年和老龄大鼠心肌细胞匀浆,老龄和成年大鼠为两大组,每组分为7小组,即每只大鼠心肌随机分到各小组中,共计14小组,每组10支试管。正常对照组:给予CO2和O2的混合气体(1∶19)通气40min;缺氧复氧组:CO2,O2,N2混合气体(5∶4∶91)通气20min后换成CO2和O2的混合气体(1∶19)通气20min;阴性对照组:同缺氧复氧组,但于再给氧前加入0.1mL的非特异性灭活兔血清;地高辛抗血清组:同缺氧复氧组,但于再给氧前加入0.1mL的非特异性地高辛抗血清(分别为1∶90000,60000,30000,10000)。观察大鼠心肌细胞钠-钾-三磷酸腺苷酶活性和线粒体内钙聚集程度,分析其剂量-效应关系。结果:①缺氧复氧时,青年组和老龄组大鼠心肌分泌内洋地黄素均显著升高,但老龄组显著低于青年组[(0.081±0.03),(0.153±0.06);(0.074±0.04),(0.125±0.05)ng/g;P<0.05]。②缺氧复氧时,老龄组与青年组心肌细胞钠-钾-三磷酸腺苷酶活性显著受抑制[(0.239±0.015),(0.778±0.050);(0.350±0.047),(0.836±0.044)μkat/g;P<0.05],老龄组与青年组相比,其抑制效应显著增强(P<0.05)。③缺氧复氧时,老龄组线粒体内钙与青年组比较明显增强[(0.082±0.011),(0.495±0.095);(0.075±0.008),(0.412±0.084)mmol/L,P<0.05]。④老龄组和青年组相比,地高辛抗血清呈剂量依赖性的恢复钠-钾-三磷酸腺苷酶活性(r=0.695,0.797,n=5,P<0.05),减轻线粒体内钙聚集(r=-0.565,-0.649,n=5,P<0.05);经直线回归分析发现,老龄鼠回归系数大于青年组(酶活性抑制K=1.50,0.94,线粒体内钙K=-7.43,-6.46)。结论:心肌细胞缺氧复氧时,老龄鼠损伤较青年大鼠更显著,其机制与老龄大鼠心肌细胞钠-钾-三磷酸腺苷酶对内洋地黄素敏感性增加有关,地高辛抗血清对老龄大鼠心肌细胞缺氧复氧保护作用更有效。 相似文献
10.
E Barrow L Robinson W Alduaij A Shenton T Clancy F Lalloo J Hill DG Evans 《Clinical genetics》2009,75(2):141-149
Lynch syndrome or hereditary non-polyposis colorectal cancer is caused by mutations of DNA mismatch repair (MMR) genes. The extracolonic tumour spectrum includes endometrial, ovarian, gastric, small bowel, pancreatic, hepatobiliary, brain, and urothelial neoplasms. Families were referred on the basis of clinical criteria. Tumour immunohistochemistry and microsatellite testing were performed. Appropriate patients underwent sequencing of relevant exons of the MMR genes. Proven and obligate mutation carriers and first-degree relatives (FDRs) with a Lynch syndrome spectrum cancer were considered mutation carriers, as were a proportion of untested, unaffected FDRs based on the proportion of unaffected relatives testing positive in each age group. Kaplan–Meier analysis of risk to 70 years was calculated. One hundred and eighty-four Lynch syndrome spectrum extracolonic cancers in 839 proven, obligate, or assumed mutation carriers were analysed. Cumulative risk for females of an extracolonic tumour is 47.4% (95% CI 43.9–50.8). The risk to males is 26.5% (95% CI 22.6–30.4). There was no reduction in gynaecological malignancies due to gynaecological screening (examination, transvaginal ultrasound scan, hysteroscopy and endometrial biopsy). Males have a higher risk of gastric cancer than females (p = 0.0003). Gastric cancer risk in those born after 1935 does not justify surveillance. These penetrance estimates have been corrected for ascertainment bias and are appropriate for those referred to a high-risk clinic. 相似文献