全文获取类型
收费全文 | 11117篇 |
免费 | 808篇 |
国内免费 | 246篇 |
专业分类
耳鼻咽喉 | 145篇 |
儿科学 | 372篇 |
妇产科学 | 123篇 |
基础医学 | 1887篇 |
口腔科学 | 142篇 |
临床医学 | 893篇 |
内科学 | 1673篇 |
皮肤病学 | 187篇 |
神经病学 | 1054篇 |
特种医学 | 414篇 |
外科学 | 1021篇 |
综合类 | 1048篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 946篇 |
眼科学 | 99篇 |
药学 | 1333篇 |
1篇 | |
中国医学 | 342篇 |
肿瘤学 | 488篇 |
出版年
2023年 | 150篇 |
2022年 | 213篇 |
2021年 | 401篇 |
2020年 | 363篇 |
2019年 | 455篇 |
2018年 | 427篇 |
2017年 | 376篇 |
2016年 | 385篇 |
2015年 | 385篇 |
2014年 | 730篇 |
2013年 | 890篇 |
2012年 | 597篇 |
2011年 | 729篇 |
2010年 | 593篇 |
2009年 | 601篇 |
2008年 | 552篇 |
2007年 | 541篇 |
2006年 | 509篇 |
2005年 | 385篇 |
2004年 | 360篇 |
2003年 | 341篇 |
2002年 | 246篇 |
2001年 | 202篇 |
2000年 | 162篇 |
1999年 | 120篇 |
1998年 | 133篇 |
1997年 | 110篇 |
1996年 | 100篇 |
1995年 | 101篇 |
1994年 | 66篇 |
1993年 | 76篇 |
1992年 | 54篇 |
1991年 | 55篇 |
1990年 | 49篇 |
1989年 | 41篇 |
1988年 | 48篇 |
1987年 | 35篇 |
1986年 | 30篇 |
1985年 | 76篇 |
1984年 | 70篇 |
1983年 | 67篇 |
1982年 | 50篇 |
1981年 | 42篇 |
1980年 | 40篇 |
1979年 | 38篇 |
1978年 | 26篇 |
1977年 | 30篇 |
1976年 | 24篇 |
1975年 | 30篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的 观察Gi13对大鼠急性血瘀模型血液流变学的影响.方法 采用皮下注射0.1%盐酸肾上腺素复合冰水浴大鼠血瘀模型,各组大鼠用乌拉坦麻醉后腹主动脉取血,测定大鼠血液流变学各参数及血小板聚集功能等指标.结果 Gi13高、中剂量组均能显著降低急性血瘀模型大鼠低切变率(1s-1)全血黏度、中切变率(50 s-1)全血黏度、血浆纤维蛋白原浓度、红细胞压积、血沉、红细胞聚集指数、血小板聚集率等指标(P<0.05).结论 Gi13对大鼠急性血瘀模型血液流变学及血小板功能的异常变化有明显的改善作用. 相似文献
992.
993.
We investigated ADAMTS13 activity as well as the ADAMTS13 gene mutation in children with hemolytic uremic syndrome (HUS). Eighteen patients, including 6 diarrhea- negative (D-HUS) and 12 diarrhea-associated HUS (D+HUS) patients, were evaluated. The extent of von Willebrand factor (VWF) degradation was assayed by multimer analysis, and all exons of the ADAMTS13 gene were PCR-amplified using Taq DNA polymerase. The median and range for plasma activity of ADAMTS13 in 6 D-HUS and 12 D+HUS patients were 71.8% (22.8-94.1%) and 84.9% (37.9-119.9%), respectively, which were not statistically significantly different from the control group (86.4%, 34.2-112.3%) (p>0.05). Five ADAMTS13 gene mutations, including 2 novel mutations [1584+2T>A, 3941C>T (S1314L)] and 3 polymorphisms (Q448E, P475S, S903L), were found in 2 D-HUS and one D+HUS patients, which were not associated with deficiency of ADAMTS13 activity. Whether these mutations without reduced ADAMTS13 activity are innocent bystanders or predisposing factors in HUS remains unanswered. 相似文献
994.
995.
Grinde MT Moestue SA Borgan E Risa Ø Engebraaten O Gribbestad IS 《NMR in biomedicine》2011,24(10):1243-1252
Tumor cells have increased glycolytic activity, and glucose is mainly used to form lactate and alanine, even when high concentrations of oxygen are present (Warburg effect). The purpose of the present study was to investigate glucose metabolism in two xenograft models representing basal-like and luminal-like breast cancer using (13) C high-resolution-magic angle spinning (HR-MAS) MRS and gene expression analysis. Tumor tissue was collected from two groups for each model: untreated mice (n=19) and a group of mice (n=16) that received an injection of [1-(13) C]-glucose 10 or 15 min before harvesting the tissue. (13) C HR-MAS MRS was performed on the tumor samples and differences in the glucose/alanine (Glc/Ala), glucose/lactate (Glc/Lac) and alanine/lactate (Ala/Lac) ratios between the models were studied. The expression of glycolytic genes was studied using tumor tissue from the same models. In the natural abundance MR spectra, a significantly lower Glc/Ala and Glc/Lac ratio (p<0.001) was observed in the luminal-like model compared with the basal-like model. In the labeled samples, the predominant glucose metabolites were lactate and alanine. Significantly lower Glc/Ala and Glc/Lac ratios were observed in the luminal-like model (p<0.05). Most genes contributing to glycolysis were expressed at higher levels in the luminal-like model (fdr<0.001). The lower Glc/Ala and Glc/Lac ratios and higher glycolytic gene expression observed in the luminal-like model indicates that the transformation of glucose to lactate and alanine occurred faster in this model than in the basal-like model, which has a growth rate several times faster than that of the luminal-like model. The results from the present study suggest that the tumor growth rate is not necessarily a determinant of glycolytic activity. 相似文献
996.
Primary immunization of humans with smallpox vaccine (live vaccinia virus (VACV)) consistently elicits antibody responses to six VACV virion membrane proteins, including A13. However, whether anti-A13 antibody contributes to immune protection against orthopoxviruses was unknown. Here, we isolated a murine monoclonal antibody (mAb) against A13 from a mouse that had been infected with VACV. The anti-A13 mAb bound to recombinant A13 protein with an affinity of 3.4 nM and neutralized VACV mature virions. Passive immunization of mice with the anti-A13 mAb protected against intranasal VACV infection. The epitope of the anti-A13 mAb was mapped to a 10-amino acid sequence conserved in all orthopoxviruses, including viriola virus and monkeypox virus, suggesting that anti-A13 antibodies elicited by smallpox vaccine might contribute to immune protection against orthopoxviruses. In addition, our data demonstrates that anti-A13 mAbs are effective for treating orthopoxvirus infection. 相似文献
997.
998.
We used fluorescence immunohistochemistry, analysis of differential interference contrast (DIC) images and confocal laser-scanning microscopy in the transmission mode, after staining specimens with toluidine blue, to examine the localization of keratin 13 (K13) and keratin 14 (K14) in the lingual epithelium of fetal and juvenile Sprague-Dawley rats during the prenatal and postnatal morphogenesis of circumvallate papillae. No immunoreactivity specific for K13 and K14 was detected in the lingual epithelium of fetuses on day 15 after conception (E15), at which time the primitive rudiment of the circumvallate papillae was detectable by the thickening of several layers of cuboidal epithelial cells. On E17 and E19, the developing circumvallate papillae were clearly recognizable, consisting of a central papilla and the surrounding sulcus. No immunoreactivity specific for K13 and K14 was evident in the lingual epithelium around these structures at this time. K14-specific immunoreactivity was first detected in the basal layer of the epithelium of the circumvallate papillae on postnatal day 0 (P0) and K13-specific immunoreactivity was detected on P7. Morphogenesis of the circumvallate papillae progressed significantly from P0 to P14, and immunoreactivity specific for K13 and K14 was clearly recognizable after P7. The respective patterns of K13-specific and K14-specific immunoreactivity differed during the development of the circumvallate papillae: K13-specific immunoreactivity was generally evident in cells of the intermediate layer of the epithelium, while K14-specific immunoreactivity was detected in cells of the basal and suprabasal layers. The present results are discussed in the context of the previously determined localization of K13 and K14 in the dorsal epithelium of the anterior part of the rat tongue during its morphogenesis. 相似文献
999.