全文获取类型
收费全文 | 183篇 |
免费 | 11篇 |
国内免费 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 5篇 |
2015年 | 16篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 6篇 |
2010年 | 9篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 9篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1971年 | 1篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1954年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有195条查询结果,搜索用时 15 毫秒
51.
Cell transplantation is a promising new modality in treating damaged myocardium after myocardial infarction and in preventing postmyocardial infarction LV remodelling. Two strategies are plausible: the first uses adult tissue stem cells to replace the scar tissues and amend the lost myocardium, whilst the second strategy uses embryonic stem cells in an attempt to regenerate myocardium and/or blood vessels. 相似文献
52.
B220+ double-negative T cells suppress polyclonal T cell activation by a Fas-independent mechanism that involves inhibition of IL-2 production 总被引:4,自引:0,他引:4
Hamad AR Mohamood AS Trujillo CJ Huang CT Yuan E Schneck JP 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(5):2421-2426
Fas-mediated apoptosis is a key mechanism for elimination of autoreactive T cells, yet loss of function mutations in the Fas signaling pathway does not result in overt T cell-mediated autoimmunity. Furthermore, mice and humans with homozygous Fas(lpr) or Fas ligand(gld) mutations develop significant numbers of B220+ CD4- CD8- double-negative (DN) alphabeta T cells (hereafter referred to as B220+ DN T cells) of poorly understood function. In this study, we show that B220+ DN T cells, whether generated in vitro or isolated from mutant mice, can suppress the ability of activated T cells to proliferate or produce IL-2, IL-10, and IFN-gamma. B220+ DN T cells that were isolated from either lpr or gld mice were able to suppress proliferation of autologous and syngeneic CD4 T cells, showing that suppression is Fas independent. Furthermore, restoration of Fas/Fas ligand interaction did not enhance suppression. The mechanism of suppression involves inhibition of IL-2 production and its high affinity IL-2R alpha-chain (CD25). Suppression also requires cell/cell contact and TCR activation of B220+ DN T cells, but not soluble cytokines. These findings suggest that B220+ DN T cells may be involved in controlling autoreactive T cells in the absence of Fas-mediated peripheral tolerance. 相似文献
53.
Reda F. M. Elshaarawy Hamad H. Abdel Gawad Hassan M. A. Hassan Reda M. Abd Alaal Eman M. Hassan Rana O. Yahya Lamia A. Ismail 《化学与生物多样性》2023,20(4):e202300152
A new chelating task-specific ionic liquid (TSIL), lutidinium-based salicylaldoxime ( LSOH ), and its square pyramidal vanadyl(II) complex (VO(LSO)2) have been successfully synthesized and structurally characterized using elemental (CHN), spectral, and thermal analyses. The catalytic activity of the lutidinium-salicylaldoxime complex (VO(LSO)2) in the alkene epoxidation reactions was studied under various reaction conditions, such as solvent effect, alkene/oxidant molar ratio, pH, reaction temperature, reaction time, and the catalyst dose. The results demonstrated that the CHCl3 solvent, 1 : 3 of the cyclohexene/H2O2 ratio, pH 8, temperature of 340 K, and catalyst dose of 0.012 mmol are assigned as the optimum conditions for achieving maximum catalytic activity for VO(LSO)2. Moreover, the VO(LSO)2 complex has the potential for application in the effective and selective epoxidation of alkenes. Notably, under optimal VO(LSO)2 conditions, cyclic alkenes convert more efficiently to their corresponding epoxides than linear alkenes. 相似文献
54.
55.
56.
57.
The present study is concerned with the selection of economically available agricultural starchy substrate for the production of alpha amylase by Bacillus licheniformis. Different agricultural starchy substrates such as soluble starch, hordium, pearl millet, rice, corn, gram and wheat starch were tested for the production of alpha amylase by parental and its mutant derivatives. The production of alpha amylase was 10-folds better by the mutant strain B. licheniformis GCUCM-30 than the parental strain when pearl millet starch at 1.5% level and nutrient broth concentrations at the level of 0.25% was supplemented to the fermentation medium. 相似文献
58.
59.
Reducing the immediate availability of red blood cells in cardiac surgery,a single-centre experience
M. C. Haanschoten A. H. M. van Straten F. Verstappen D. van de Kerkhof A. A. J. van Zundert M. A. Soliman Hamad 《Netherlands heart journal》2015,23(1):28-32
Background
In our institution, we have redefined our criteria for direct availability of red blood cell (RBC) units in the operation room. In this study, we sought to evaluate the safety of applying this new logistical policy of blood transfusion in the first preliminary group of patients.Methods
In March 2010, we started a new policy concerning the elective availability of RBC units in the operation room. This policy was called: No Elective Red Cells (NERC) program. The program was applied for patients undergoing primary isolated coronary artery bypass grafting (CABG) or single valve surgery. No elective RBC units were preoperatively ordered for these patients. In case of urgent need, blood was delivered to the operating room within 20 min. The present study includes the first 500 patients who were managed according to this policy. Logistic regression analyses were performed to investigate the impact of biomedical variables on fulfilling this NERC program.Results
The majority of patients (n = 409, 81 %) did not receive any RBCs during the hospital stay. In patients who did receive RBCs (n = 91, 19 %), 11 patients (2.2 %) received RBCs after 24 h postoperatively. Female gender, left ventricular ejection fraction (LVEF) and EuroSCORE were significant predictors for the need of blood transfusion (OR = 3.12; 2.79; 1.17 respectively).Conclusion
In a selected group of patients, it is safe to perform cardiac surgery without the immediate availability of RBCs in the operating room. Transfusion was avoided in 81 % of these patients. Female gender, LVEF and EuroSCORE were associated with blood transfusion. 相似文献60.
M. Zandipour M. Khodarahmi E. Majidi SH. Ebrahim-nejad 《Archives Of Phytopathology And Plant Protection》2013,46(12):1459-1465
In order to investigate heritability and gene action for yellow rust resistance in wheat, a resistance yellow rust cultivar Aflak was crossed to susceptible cultivar Avocet‘s’. Parents, F1, F2 and F3 generations were cultured according to randomised complete block design with two replications in the research station of Gharakhil, Iran. Parents and other generations were inoculated with 70E0A+ race. Traits including severity and infection type were recorded and then coefficient of infection was calculated. For this trait, generations mean and variance analysis were performed and results showed that there were significant differences among generations for coefficient of infection. Results showed that in addition to additive and dominance effects, at least one kind of epistasis interaction (additive × additive) control this trait. Although additive and dominance effects control this trait, but with attention to generations variance analysis, the results showed that additive variance had important role to control this trait. 相似文献