全文获取类型
收费全文 | 1650篇 |
免费 | 164篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 8篇 |
妇产科学 | 9篇 |
基础医学 | 160篇 |
口腔科学 | 31篇 |
临床医学 | 65篇 |
内科学 | 217篇 |
皮肤病学 | 12篇 |
神经病学 | 175篇 |
特种医学 | 43篇 |
外科学 | 64篇 |
综合类 | 208篇 |
预防医学 | 93篇 |
眼科学 | 7篇 |
药学 | 362篇 |
中国医学 | 398篇 |
肿瘤学 | 49篇 |
出版年
2024年 | 12篇 |
2023年 | 30篇 |
2022年 | 82篇 |
2021年 | 103篇 |
2020年 | 87篇 |
2019年 | 56篇 |
2018年 | 69篇 |
2017年 | 67篇 |
2016年 | 64篇 |
2015年 | 66篇 |
2014年 | 120篇 |
2013年 | 122篇 |
2012年 | 73篇 |
2011年 | 87篇 |
2010年 | 59篇 |
2009年 | 70篇 |
2008年 | 60篇 |
2007年 | 56篇 |
2006年 | 38篇 |
2005年 | 42篇 |
2004年 | 38篇 |
2003年 | 40篇 |
2002年 | 28篇 |
2001年 | 24篇 |
2000年 | 21篇 |
1999年 | 23篇 |
1998年 | 25篇 |
1997年 | 20篇 |
1996年 | 19篇 |
1995年 | 15篇 |
1994年 | 18篇 |
1993年 | 25篇 |
1992年 | 21篇 |
1991年 | 19篇 |
1990年 | 17篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 18篇 |
1984年 | 21篇 |
1983年 | 17篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1973年 | 3篇 |
排序方式: 共有1906条查询结果,搜索用时 15 毫秒
941.
942.
目的 探讨METTL3调控SPRING1促进巨噬细胞脂质蓄积的作用及机制。 方法 100 ng/mL PMA诱导THP-1细胞贴壁后,50 μg/mL Ac-LDL孵育THP-1细胞。Western blot测定METTL3和SPRING1蛋白;qRT-PCR测定SPRING1mRNA水平;细胞内总胆固醇、胆固醇酯以及游离胆固醇变化用高效液相色谱法检测;SRAMP和RMBase网站分析SPRING1 mRNA上的m6A修饰位点情况;质膜红色荧光标记探针Dil-Ac-LDL观察巨噬细胞脂滴摄取情况。 结果 与对照组相比,Ac-LDL孵育后THP-1细胞METTL3和SPRING1蛋白表达上调,并且SPRING1 mRNA水平上调;过表达METTL3会使SPRING1蛋白表达上调,巨噬细胞对脂质摄取增加,细胞内Dil-Ac-LDL明显增多;反之,沉默METTL3表达,SPRING1蛋白表达下调;甲基化抑制剂环亮氨酸处理可部分抑制METTL3过表达对SPRING1表达的促进作用;生物信息学分析显示,SPRING1 mRNA存在m6A修饰位点。 结论 METTL3上调SPRING1表达,促进巨噬细胞脂质蓄积。 相似文献
943.
944.
YI GANG WAN~ WEI SUN~~ Department of Traditional Chinese Medicine Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing P. R. China~ Department of Cell Biology Institute of Nephrology Faculty of Medicine Niigata University Niigata - Japan~ Department of Nephrology Affiliated Hospital of Nanjing University of Traditional Chinese Medicine Nanjing P. R. China 《中华微生物学和免疫学杂志(英文版)》2005,3(3):165-173
Tripterygium wilfordii Hook.f.is a well-knownimmunosuppressive Chinese herb.The mainactivecomponents fromthis herb is a stable glycoside ,called multi-glycoside ofTripterygium wilfordiiHook.f. ( GTW) [1] , which has been widelyusedfor treatment of a variety of autoimmune dis-eases ,such as rheumatoid arthritis [2] ,glomeru-lonephritis (GN) [3] and systemic lupus erythe-matosus (SLE) [4] .GTWhas been reported to be beneficial tothe treatment of several types of nephritis .It couldeffectiv… 相似文献
945.
添加葡萄糖的脱水甘蓝在贮藏过程中葡萄糖极易从甘蓝内部迁移到表面.实验结果表明,渗糖处理时添加一定量的乳糖和高麦芽糖浆代替葡萄糖,对延长脱水甘蓝的返霜期有良好的效果,高麦芽糖浆对延长脱水甘蓝返霜的效果明显好于乳糖.实验还研究了热烫时间、贮藏环境的相对湿度对葡萄糖迁移影响的规律.热烫90s、贮藏在较低的环境湿度下均有利于延长脱水甘蓝的返霜天数. 相似文献
946.
Kenshi Matsumoto Yukio Fujiwara Ryoji Nagai Masaki Yoshida Shoichi Ueda 《International journal of urology》2008,15(2):166-170
Objectives: The present study investigated the expression of acyl-coenzyme A: cholesterol acyltransferase-1 (ACAT-1) and -2 in clear cell type renal cell carcinoma (RCC).
Methods: Clear cell type RCC and corresponding normal kidney tissue samples were obtained from 19 surgical cases (28–85 years of age). Tissue extracts were assayed for ACAT activity and protein expression by immunoblotting with anti-ACAT-1 and anti-ACAT-2 antibodies. Frozen sections were subjected to Oil red O staining for lipids, and were immunostained with ACAT-specific antibodies.
Results: Acyl-coenzyme A cholesterol acyltransferase activity was 5.7-fold higher ( P < 0.01) in clear cell carcinoma (23.52 ± 4.90 pmol/mg protein/min) than in normal kidney (4.12 ± 0.36). Consistent with this, immunoblotting and immunohistochemical staining revealed strong expression of ACAT-1 in clear cell type RCC. Densitometric analysis showed that ACAT-1 expression was 2.9-fold higher in clear cell type RCC than in normal kidney. In contrast, ACAT-2 expression was negative in clear cell type RCC and normal kidney. Oil red O staining showed massive deposits of lipid in RCC cells.
Conclusions: We identified strong expression of ACAT-1 in clear cell type RCC. Upregulation of ACAT-1 leads to high ACAT enzymatic activity, which accelerates the accumulation of cholesterol ester in clear cell type RCC. 相似文献
Methods: Clear cell type RCC and corresponding normal kidney tissue samples were obtained from 19 surgical cases (28–85 years of age). Tissue extracts were assayed for ACAT activity and protein expression by immunoblotting with anti-ACAT-1 and anti-ACAT-2 antibodies. Frozen sections were subjected to Oil red O staining for lipids, and were immunostained with ACAT-specific antibodies.
Results: Acyl-coenzyme A cholesterol acyltransferase activity was 5.7-fold higher ( P < 0.01) in clear cell carcinoma (23.52 ± 4.90 pmol/mg protein/min) than in normal kidney (4.12 ± 0.36). Consistent with this, immunoblotting and immunohistochemical staining revealed strong expression of ACAT-1 in clear cell type RCC. Densitometric analysis showed that ACAT-1 expression was 2.9-fold higher in clear cell type RCC than in normal kidney. In contrast, ACAT-2 expression was negative in clear cell type RCC and normal kidney. Oil red O staining showed massive deposits of lipid in RCC cells.
Conclusions: We identified strong expression of ACAT-1 in clear cell type RCC. Upregulation of ACAT-1 leads to high ACAT enzymatic activity, which accelerates the accumulation of cholesterol ester in clear cell type RCC. 相似文献
947.
S Bott C Tusek L V Jacobsen L Endahl E Draeger C Kapitza T Heise 《Diabetic medicine》2006,23(5):522-528
AIMS: This study investigated the pharmacodynamic and pharmacokinetic characteristics of the novel long-acting insulin analogue insulin detemir (IDet) under single-dose and steady-state conditions in comparison with those of NPH insulin at steady state. METHODS: Twenty-five subjects with Type 1 diabetes [seven females, 18 males, mean age (+/- sd) 39 +/- 12 years, body mass index 24 +/- 3 kg/m(2)] participated in three 24-h glucose clamps. IDet or NPH were given at 12-h intervals in fixed, individualized doses. The first clamp assessed the metabolic effect of NPH at steady state, the second investigated the effect of two single injections of IDet. Subjects continued IDet treatment for 7-14 days, after which the third clamp was performed to investigate IDet at steady state. RESULTS: At steady state, the metabolic effect of IDet was constant over 24 h while a clear peak in the metabolic effect [expressed as glucose infusion rates (GIR)] was observed with NPH after each injection. The fluctuation in the metabolic effect (maximum GIR divided by the average of the GIR values at the interval ends) was significantly lower in the second 12 h of the experiments with IDet under steady-state conditions compared with NPH (fluctuation(12-24 h) 1.27 +/- 0.17 vs. 1.56 +/- 0.72, P < 0.05). The overall metabolic effect of IDet at steady state was comparable with that of NPH [GIR-area under curve (AUC)(0-24 h): 5697 +/- 1861 vs. 5929 +/- 1965 mg/kg] whereas a significantly lower effect (5187 +/- 1784 mg/kg, P = 0.01 vs. steady state) was observed following the first two IDet injections. GIR values at the end of clamp day 2 (first doses) and clamp day 3 (steady state) were comparable [GIR(trough 24 h) 3.7 +/- 1.7 vs. 3.8 +/- 1.6 mg/(kg x min) NS], indicating that IDet had reached steady state after the first two injections. CONCLUSIONS: IDet administered twice daily reached steady state after the second injection and showed a constant metabolic effect over time under steady-state conditions. This should facilitate basal insulin substitution and decrease the risk of hypoglycaemia in insulin-treated subjects. 相似文献
948.
K. Freeman A. Gregory A. Turner P. Blasco P. Hogarth & S. Hayflick 《Journal of intellectual disability research : JIDR》2007,51(6):417-426
Background Pantothenate kinase‐associated neurodegeneration (PKAN), an extremely rare autosomal recessive disorder resulting in iron accumulation in the brain, has a diverse phenotypic expression. Based on limited case studies of one or two patients, intellectual impairment is considered part of PKAN. Investigations of cognitive functioning have utilized specific neuropsychological tests, without attention to general intellectual skills or adaptive behaviour. Methods Sixteen individuals with PKAN completed measures of global intellectual functioning, and participants or care providers completed measures of adaptive behaviour skills and day‐to‐day functional limitations. Clinicians provided global ratings of condition severity. Results Testing with standardized measures documented varied phenotypic expression, with general cognitive skills and adaptive behaviour ranging from high average to well below average. Age of disease onset correlated with measures of intellectual functioning, adaptive functioning and disease severity. Conclusions Findings support previously described clinical impressions of varied cognitive impairment and the association between age of onset and impairment. Further, they add important information regarding the natural history of the disease and suggest assessment strategies for use in treatment trials. 相似文献
949.
William R Mundy Theresa M Freudenrich Kevin M Crofton Michael J DeVito 《Toxicological sciences》2004,82(1):164-169
A number of recent studies have examined the neurotoxic actions of polybrominated diphenyl ethers (PBDEs) using in vitro cell culture models. However, there are few data reporting the final concentration of PBDEs in cells after in vitro exposure to these compounds. To address this issue, the present study examined the concentration-dependent and time-dependent accumulation of 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) in primary cultures of rat neocortex. Mixed cultures of neuronal and glial cells were prepared from the neocortex of newborn rats and grown for 7 days in vitro. The cells were then exposed to freshly prepared serum-free culture medium containing (14)C-PBDE-47. Radiolabel associated with the cells or remaining in the medium was determined by liquid scintillation spectrometry. Exposure to 0.01-3.0 microM PBDE-47 for 60 min resulted in a concentration-dependent accumulation in cells. At each concentration, approximately 15% of the applied PBDE-47 was associated with the cells, resulting in a 100-fold magnification of the applied concentration (e.g., a 60-min exposure to 1 microM resulted in an approximate 100 microM concentration in the cells); 55% of the PBDE remained in the medium and 30% was associated with the plastic culture dish. Exposure to 1 microM PBDE-47 resulted in a linear increase in PBDE-47 in cells with time for the first 60 min, which began to saturate at 120 min. Addition of serum proteins to the medium decreased accumulation; at 10% serum in the medium, only 3% of the applied PBDE-47 was associated with the cells and 96% remained in the media after 60 min. The total volume of exposure also influenced accumulation of PBDE-47. Doubling the volume of serum-free exposure medium (from 2 ml to 4 ml) but leaving the concentration constant (1 microM) resulted in a 1.5-fold increase in PBDE-47 concentration in the cells. These data show that a number of factors, including duration of exposure, volume of exposure, and concentration of serum proteins in the medium, can influence the accumulation of PBDE-47 in cells in vitro. For this highly lipophilic compound, use of medium concentration underestimates tissue concentration by up to two orders of magnitude. Thus, accurate information on the tissue concentration for in vitro experiments should be determined empirically. 相似文献
950.
上海市二、三级医院品牌现状分析及其影响因素 总被引:5,自引:1,他引:4
通过对上海市二、三级医院的调查,分析了上海市二、三级医院的品牌现状,并且从医院内部因素、外部因素、医院品牌历史沉积三方面对影响医院品牌的因素进行了分析总结. 相似文献