全文获取类型
收费全文 | 3788篇 |
免费 | 340篇 |
国内免费 | 325篇 |
出版年
2024年 | 4篇 |
2023年 | 44篇 |
2022年 | 110篇 |
2021年 | 200篇 |
2020年 | 131篇 |
2019年 | 165篇 |
2018年 | 155篇 |
2017年 | 123篇 |
2016年 | 184篇 |
2015年 | 224篇 |
2014年 | 248篇 |
2013年 | 280篇 |
2012年 | 319篇 |
2011年 | 289篇 |
2010年 | 185篇 |
2009年 | 165篇 |
2008年 | 205篇 |
2007年 | 154篇 |
2006年 | 167篇 |
2005年 | 145篇 |
2004年 | 136篇 |
2003年 | 107篇 |
2002年 | 115篇 |
2001年 | 97篇 |
2000年 | 85篇 |
1999年 | 79篇 |
1998年 | 46篇 |
1997年 | 44篇 |
1996年 | 38篇 |
1995年 | 34篇 |
1994年 | 28篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 23篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 10篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有4453条查询结果,搜索用时 15 毫秒
931.
Yuhua Hao Wanguo Bao Meishan Jin Yuxiang Li Feng Wang 《The Korean journal of parasitology》2016,54(3):323-327
A man with only yellowing of the skin and eye sclera was diagnosed with clonorchiasis, which rarely manifested jaundice as the initial symptom. However, because of a lack of evidence for a diagnostic gold standard, the time until definitive diagnosis was more than a week. The diagnostic process relied on inquiring about the patient’s history, including the place of residence, dietary habits, and symptoms, as well as on serological findings, an imaging examination, and pathological findings. MRCP and CT results showed mild dilatation of intrahepatic ducts and increased periductal echogenicity. The eggs were ultimately found in stool by water sedimentation method after the negative report through direct smear. DNA sequencing of PCR production of the eggs demonstrated 98-100% homology with ITS2 of Clonorchis sinensis. After anti-parasite medical treatment, the patient’s symptoms were gradually relieved. Throughout the diagnostic procedure, besides routine examinations, the sedimentation method or concentration method could be used as a sensitive way for both light and heavy C. sinensis infection in the definite diagnosis. 相似文献
932.
933.
934.
935.
Xuan Cai Lihui Zhu Xiaolian Chen Yongshuai Sheng Qi Guo Jian Bao Jianxiong Xu 《Cytotechnology》2016,68(4):713-724
We previously demonstrated that intestinal epithelial cell apoptosis in weaned piglets is much more serious than that observed in sucking piglets and is related to oxidative stress during weaning. It is difficult to study the apoptosis mechanisms only using in vivo methods because of the limit of existing research technology. An in vitro cellular system is required for piglet intestinal epithelial cell apoptosis research. In this study, a non-tumorigenic epithelial cell line, IPEC-J2 cells, was employed as a cell model. Hydrogen peroxide and xanthine/xanthine oxidase (X/XO) were both used and compared for apoptosis modeling. The concentrations of hydrogen peroxide and XO were selected and verified using cell viability analysis, the comet assay and flow cytometry. Intracellular ROS were measured using fluorescent probes. Additionally, the expression levels of the apoptosis-related genes Fas, Bcl-2, P53, Caspase 3, Caspase 8, and Caspase 9 were analyzed using quantitative RT-PCR. The results indicated the optimal modeling method is a final concentration of 0.5 mM H2O2 incubated with IPEC-J2 cells for 1 h at 37 °C in 5 % CO2 for hydrogen peroxide-induced apoptosis modeling, and a final concentration of 250 μM X/50 U/L XO incubated with IPEC-J2 cells for 6 h at 37 °C in 5 % CO2 for X/XO-induced apoptosis modeling. For the apoptotic pathway, the X/XO modeling method is more similar to 21 days weaning piglets. Therefore, we suggest that X/XO modeling with IPEC-J2 cells be used as an in vitro cell culture model for weaning piglet intestinal epithelial cell apoptosis. 相似文献
936.
Qinhong Liu Cuijie Zhang Yihui Cheng Bo Zheng Manzhu Bao Xueping Shi 《Trees - Structure and Function》2016,30(4):1033-1043
937.
Using resonance light scattering and UV/vis absorption spectroscopy to study the interaction between gliclazide and bovine serum albumin
下载免费PDF全文
![点击此处可从《Luminescence》网站下载免费的PDF全文](/ch/ext_images/free.gif)
At different temperatures (298, 310 and 318 K), the interaction between gliclazide and bovine serum albumin (BSA) was investigated using fluorescence quenching spectroscopy, resonance light scattering spectroscopy and UV/vis absorption spectroscopy. The first method studied changes in the fluorescence of BSA on addition of gliclazide, and the latter two methods studied the spectral change in gliclazide while BSA was being added. The results indicated that the quenching mechanism between BSA and gliclazide was static. The binding constant (Ka), number of binding sites (n), thermodynamic parameters, binding forces and Hill's coefficient were calculated at three temperatures. Values for the binding constant obtained using resonance light scattering and UV/vis absorption spectroscopy were much greater than those obtained from fluorescence quenching spectroscopy, indicating that methods monitoring gliclazide were more accurate and reasonable. In addition, the results suggest that other residues are involved in the reaction and the mode ‘point to surface’ existed in the interaction between BSA and gliclazide. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
938.
939.
Recent genome-wide association studies (GWAS) demonstrated that genetic variation in intron 2 of fibroblast growth factor receptor 2 (FGFR2) was a novel risk for breast cancer. We investigated whether two SNPs rs1219648 and rs2981582 in intron 2 of FGFR2 were associated with the risk of breast cancer in Chinese women. A total of 340 female breast cancer patients and 400 normal age-matched controls were recruited. Two SNPs were genotyped using matrix-assisted laser desorption/ionization mass spectrometry. The two SNPs rs1219648 and rs2981582 showed no association with the risk of breast cancer. A subgroup analysis by menopausal status demonstrated that the distribution of rs2981582 T alleles, including CT and TT genotypes, was significantly higher in premenopausal patients compared with postmenopausal patients. The TT genotype in rs2981582 was more strongly associated with ER-positive than with ER-negative tumors by ER status analysis. Analysis by haplotypes showed that no haplotypes associated with breast cancer. The results showed no association between two SNPs, rs1219648 and rs2981582 and breast cancer risk, although in a stratified analysis rs2981582 strongly associated with premenopausal and ER-positive breast cancer patients in Chinese women. 相似文献
940.