全文获取类型
收费全文 | 3792篇 |
免费 | 161篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 81篇 |
妇产科学 | 18篇 |
基础医学 | 431篇 |
口腔科学 | 67篇 |
临床医学 | 256篇 |
内科学 | 1174篇 |
皮肤病学 | 56篇 |
神经病学 | 201篇 |
特种医学 | 174篇 |
外科学 | 755篇 |
综合类 | 14篇 |
预防医学 | 74篇 |
眼科学 | 42篇 |
药学 | 220篇 |
中国医学 | 19篇 |
肿瘤学 | 391篇 |
出版年
2023年 | 18篇 |
2022年 | 46篇 |
2021年 | 81篇 |
2020年 | 48篇 |
2019年 | 63篇 |
2018年 | 89篇 |
2017年 | 95篇 |
2016年 | 85篇 |
2015年 | 116篇 |
2014年 | 137篇 |
2013年 | 173篇 |
2012年 | 241篇 |
2011年 | 283篇 |
2010年 | 151篇 |
2009年 | 134篇 |
2008年 | 204篇 |
2007年 | 230篇 |
2006年 | 208篇 |
2005年 | 248篇 |
2004年 | 240篇 |
2003年 | 232篇 |
2002年 | 204篇 |
2001年 | 38篇 |
2000年 | 35篇 |
1999年 | 38篇 |
1998年 | 40篇 |
1997年 | 31篇 |
1996年 | 40篇 |
1995年 | 38篇 |
1994年 | 27篇 |
1993年 | 21篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 30篇 |
1988年 | 27篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 19篇 |
1984年 | 23篇 |
1983年 | 15篇 |
1982年 | 9篇 |
1981年 | 19篇 |
1980年 | 11篇 |
1979年 | 17篇 |
1978年 | 22篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1974年 | 5篇 |
1966年 | 7篇 |
排序方式: 共有3980条查询结果,搜索用时 0 毫秒
61.
Ritsuko Nishide Michiko Ando Hidemitsu Funabashi Yoshiko Yoda Masataka Nakano Masayuki Shima 《Environmental health and preventive medicine》2015,20(2):116-122
Objectives
To investigate the association of serum lipids and high-sensitivity C-reactive protein (hs-CRP) with obesity in school children and to explore whether hs-CRP levels could be used to predict the presence or absence of obesity 12 months later.Methods
The subjects were school children (6–11 years old) in Japan. Blood sampling and physical measurements were performed in school (2001); low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, and hs-CRP levels were measured. Data from children who could be followed 12 months later were analyzed. Subjects weighing 20 % or more over his/her standard weight were regarded as obese, and the association of obesity with serum parameters was analyzed.Results
Data from 612 subjects were analyzed (follow-up rate, 75.4 %). The mean of each serum parameter was significantly higher (inverse for HDL-C; lower) in obese than that in non-obese children. Logistic regression analysis for obesity at baseline showed that the odds ratio (OR) of hs-CRP was the highest [OR, 2.15; 95 % confidence interval (CI), 1.65–2.78 for an interquartile rage (IQR) increase]; the association with triglycerides and LDL-C/HDL-C was significant. At the 12-month follow-up, the OR of high hs-CRP remained the highest of all serum parameters (2.09; 95 % CI, 1.63–2.69 for an IQR increase).Conclusions
High levels of triglycerides, LDL-C/HDL-C, and hs-CRP increased the risk of obesity in school children. Hs-CRP is considered to be a better predictor of obesity 12 months later than is LDL-C/HDL-C. 相似文献62.
Matsumoto Kazuhisa Tobiume Takeshi Matsuura Tomomi Ise Takayuki Kusunose Kenya Yamaguchi Koji Yagi Shusuke Fukuda Daijyu Wakatsuki Tetsuzo Yamada Hirotsugu Soeki Takeshi Sata Masataka 《Journal of interventional cardiac electrophysiology》2022,63(2):417-424
Journal of Interventional Cardiac Electrophysiology - Previous studies examined the right atrial (RA) input site of the antegrade fast pathway (AFp) (AFpI). However, the left atrial (LA) input to... 相似文献
63.
64.
Impaired synthesis of retinol-binding protein and transthyretin in rat liver with bile duct obstruction 总被引:1,自引:0,他引:1
Toru Imamine MD PhD Masataka Okuno MD PhD Hisataka Moriwaki MD PhD Yoshihiro Shidoji PhD Dr. Yasutoshi Muto MD PhD Mitsuru Seishima MD PhD Akio Noma MD PhD Soichi Kojima PhD 《Digestive diseases and sciences》1996,41(5):1038-1042
To gain further insight into the protein metabolism in bile duct-obstruction, we examined the synthesis of retinol-binding protein (RBP) and transthyretin (TTR) in rats with common bile duct-ligation. In these rats, liver and plasma levels of RBP and TTR decreased markedly, whereas liver retinoid contents remained unchanged. Although there appeared no decrease in the total amount of RBP or TTR mRNA expressed in the liver, the subcellular distribution of these mRNAs changed from the membrane-bound polysome fraction to the membrane-unbound polysome fraction. This abnormal distribution recovered rapidly after biliary drainage, resulting in the subsequent recovery of the plasma RBP and TTR levels. These observations suggest that cholestasis inhibits the synthesis and secretion of RBP and TTR by disrupting the binding of their mRNAs to membrane-bound polysomes. Plasma levels of RBP and TTR might be sensitive indicators of the recovery of protein synthesis after biliary drainage in patients with obstructive biliary disorders.Supported in part by Grant-in-Aids from the Ministry of Education, Science and Culture (05770350 to M.O.; 05670463 to H.M.; 07780553 to S.K.) and by a grant from the Ryoichi Naito Foundation for medical research (to S.K.). 相似文献
65.
The Role of Autoreactive T-cells in the Pathogenesis of Idiopathic Thrombocytopenic Purpura 总被引:4,自引:0,他引:4
Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease mediated by antiplatelet autoantibodies. The major target of these autoantibodies is a platelet membrane glycoprotein, GPIIb-IIIa, which is a receptor for fibrinogen and other ligands. We recently identified CD4+ T-cells autoreactive to GPIIb-IIIa in ITP patients. These T-cells are considered pathogenic because they help B-cells produce antibodies that bind to normal platelet surfaces. GPIIb-IIIa-reactive T-cells respond to chemically reduced and tryptic peptides of GPIIb-IIIa but not to native GPIIb-IIIa, indicating that the epitopes they recognize are "cryptic" determinants generated at a subthreshold level by the processing of native GPIIb-IIIa under normal circumstances. Although GPIIb-IIIa-reactive T-cells are also detected in healthy individuals, they are activated in vivo only in ITP patients. Activation of GPIIb-IIIa-specific T-cells and the subsequent production of pathogenic anti-GPIIb-IIIa antibodies can be induced by functional antigen-presenting cells in the spleen that present cryptic GPIIb-IIIa peptides to these T-cells. The pathogenic process of ITP can be explained as a continuous loop in which B-cells produce antiplatelet autoantibodies, splenic macrophages phagocytose antibody-coated platelets and present GPIIb-IIIa-derived cryptic peptides, and GPIIb-IIIa-reactive CD4+ T-cells exert their helper activity. Further studies examining the mechanisms that induce the processing and presentation of cryptic peptides derived from the platelet antigen at disease onset will clarify how the pathogenic autoantibody response in ITP is initiated. 相似文献
66.
67.
p38丝裂原活化蛋白激酶信号途径在鼠破骨细胞生成和骨吸收中的作用 总被引:1,自引:0,他引:1
目的研究p38丝裂原活化蛋白激酶(p38MAPK)信号途径在甲状旁腺素相关肽(PTHrP)诱导的破骨细胞生成和骨吸收中的作用。方法取小鼠骨髓细胞,在PTHrP(45ng/ml)的刺激下,在不同试验组中分别入0.1、1.0及10μmol/L的p38MAPK抑制剂Fr167653,继续培养6d。抗酒石酸染色,进行破骨细胞计数。在小鼠颅骨部位注射PTHrP建立骨吸收和高钙血症动物模型。每日给予p38MAPK抑制剂Fr16765330mg/kg,每日2次,X线片观察骨吸收面积,组织学检查计算单位面积内破骨细胞数目,采集血样观察全血内游离钙水平。结果PTHrP刺激下,大量破骨细胞生成(118.9±28.3)个/孔;加入0.1μmol/LFr167653可以部分抑制破骨细胞的生成(79.6±28.0)个/孔,加入10μmol/LFr167653几乎全抑制了破骨细胞生成(7.4±0.4)个/孔,每日给予Fr16765330mg/kg,每日2次,可以明显抑制骨吸收,表现为X线片上骨吸收面积减少,单位面积内破骨细胞数目减少,但是并不能有效地抑制高钙血症。结论抑制p38MAPK信号途径可以抑制破骨细胞的分化和局部骨吸收。 相似文献
68.
Tadashi Hasegawa Masataka Kikuyama Kazushi Sakurai Yasuhiro Kambayashi Masakazu Adachi Abby R. Saniabadi Hiroyuki Kuwano Minoru Nakano 《Liver international》2002,22(4):321-329
Abstract: Background/Aims: The aim of this study was to clarify the candidate cells for and the mechanism of superoxide anion (O2·?) release into the hepatic sinusoids during short‐term exposure to ethanol. Methods: The rat liver was perfused continuously with ethanol (a substrate for alcohol dehydrogenase) or tert‐buthanol (not a substrate for alcohol dehydrogenase) for 20 min at a final concentration of 40 mM. In order to detect O2·? production, MCLA (2‐methyl‐6‐[p‐methoxyphenyl]‐3,7‐dihydroimidazo[1,2‐a]pyrazin‐3‐one), a Cypridina luciferin analogue, was simultaneously infused and MCLA‐enhanced chemiluminescence was measured. The effects of gadolinium chloride (GdCL3) (a suppressor of Kupffer cells (KCs)), staurosporine (ST) (an inhibitor of serine–threonine kinases, including protein kinase C), diphenyleneiodonium chloride (DPI) (an inhibitor of NADPH oxidase), ibuprofen (IB) (an inhibitor of cyclooxygenase) and 4‐methylpyrazole (4MP) (an inhibitor of ethanol metabolism) on the ethanol‐induced chemiluminescence were also evaluated. Sites where O2·? could be released were determined by histochemical detection of nitro blue tetrazolium reduction. Results: Both ethanol and tert‐buthanol rapidly caused O2·? release. GdCL3 suppressed the ethanol‐induced O2·? release by 61%. Staurosporine and DPI, but neither IB nor 4‐MP, also significantly inhibited the ethanol‐induced O2·? release. In the histochemical examination, ethanol‐stimulated liver showed blue formazan precipitate on both sinusoidal endothelial cells (SECs) and Kupffer cells (KCs), whereas the GdCl3‐pretreated liver had the precipitate only on SECs. Conclusions: This study shows that ethanol itself stimulates both SECs and KCs to release O2·? via activation of NADPH oxidase probably involving protein kinase C (PKC). 相似文献
69.
Yamashita K Miyoshi T Arai T Endo N Itoh H Makino K Mizugishi K Uchiyama T Sasada M 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(44):16912-16917
Reactive oxygen species produced by phagocytosing neutrophils are essential for innate host defense against invading microbes. Previous observations revealed that antibody-catalyzed ozone formation by human neutrophils contributed to the killing of bacteria. In this study, we discovered that 4 amino acids themselves were able to catalyze the production of an oxidant with the chemical signature of ozone from singlet oxygen in the water-oxidation pathway, at comparable level to antibodies. The resultant oxidant with the chemical signature of ozone exhibited significant bactericidal activity in our distinct cell-free system and in human neutrophils. The results also suggest that an oxidant with the chemical signature of ozone produced by neutrophils might potentiate a host defense system, when the host is challenged by high doses of infectious agents. Our findings provide biological insights into the killing of bacteria by neutrophils. 相似文献
70.