首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   176篇
  免费   13篇
  189篇
  2022年   12篇
  2021年   10篇
  2020年   22篇
  2019年   16篇
  2018年   15篇
  2017年   10篇
  2016年   16篇
  2015年   13篇
  2014年   7篇
  2013年   11篇
  2012年   15篇
  2011年   14篇
  2010年   4篇
  2009年   4篇
  2008年   6篇
  2007年   5篇
  2006年   2篇
  2005年   3篇
  2004年   1篇
  2001年   1篇
  2000年   1篇
  1991年   1篇
排序方式: 共有189条查询结果,搜索用时 8 毫秒
31.
32.
As the main source of lipids and proteins in honey bees, pollen is a major nutrient provider involved in development and health and has been studied for tolerance stimulation against pathogens and parasites. In the case of Varroa destructor Anderson & Trueman (Acari, Mesostigmata: Varroidae) parasitization, the lack of a complete laboratory system to rear both the bee larva and the acarian parasite limited the studies concerning larval nutrition effects on the bee tolerance and resistance against varroatosis. Due to the development of this complete rearing protocol, we managed to feed young honey bee larvae with pollen supplemented solutions and to study the effect on their later development under parasitism conditions. In our experimental conditions, pollen influences neither the deformity rate, nor the survival of bees both parasitized and unparasitized. However, pollen extract supplementation seems to significantly impact the weight of the spinning bee larvae without having an effect on the physiological weight loss during pupation, so the differences found at the larval stage remain the same as at emergence. Varroa has a deleterious effect on bee pupae and led to a steady increase of the physiological weight loss experienced during metamorphosis. Interestingly, this ponderal loss associated with Varroa parasitization seems to be reduced in the polyfloral pollen supplementation condition. Altogether, this work is to our knowledge the first to study in laboratory conditions the impact of larval nutrition on the tolerance to parasitism. A diverse pollen diet may be beneficial to the bees’ tolerance against V. destructor parasitism.  相似文献   
33.
Five percent of all epilepsy cases are attributed to traumatic brain injury (TBI), which are known as post-traumatic epilepsy (PTE). Finding preventive strategies for PTE is valuable. Remarkable feature of TBI is activation of microglia and subsequent neuroinflammation, which provokes epileptogenesis. The toll-like receptor agonists monophosphoryl lipid A (MPL) and tri-palmitoyl-S-glyceryl-cysteine (Pam3Cys) are safe, well-tolerated and effective adjuvants existing in prophylactic human vaccines. We examined the impact of early injection of MPL and Pam3Cys to rats, on the rate of kindled seizures acquisition following TBI. Rats received a single dose (1 µg/rat) of MPL or Pam3Cys through intracerebroventricular injection. 5 days later, trauma was exerted to temporo-parietal cortex of rats by controlled cortical impact device. After 24 h, traumatic rats underwent amygdala kindling. Brain level of the inflammatory cytokine tumor necrosis factor-alpha (TNF-α) was also measured in traumatic rats by immunoblotting. Compared to non-traumatic (sham-operated) rats, traumatic rats showed three times lower seizure threshold (133?±?5 µA vs. 416.3?±?16 µA, p?<?0.001); about three times less number of stimuli to become kindled (5?±?1 vs. 14?±?2, p?<?0.01); longer duration of kindled seizure parameters including entire seizure behavior, generalized seizures, and afterdischarges (p?<?0.001); and a two times increase in the TNF-α level. MPL and Pam3Cys did not change kindling rate and the seizure parameters in sham-operated rats. The MPL- and Pam3Cys-pretreated traumatic rats displayed seizure threshold, speed of kindling, and duration of kindled seizure parameters, similar to the non-traumatic rats. Pretreatment by MPL and Pam3Cys prevented the increase in TNF-α level by trauma. Given that MPL and Pam3Cys currently have clinical use as well-tolerated vaccines with reliable safety, they have the potential to be used in prevention of PTE.  相似文献   
34.
Fully matured DCs with large amount cytoplasm and copious dendritic projections were visible at the end of culturing period in the presence of MCM, TNF-α and poly (I:C), with or without FEECM. Thus, DCs generated with these maturation factors are nonadherent and have typical satellite morphology. Flow cytometric analysis using anti-CD14, -CD80, -CD86, -HLA-DR and -CD83 revealed that expression of CD14 is decreased in particular in FEECM treated DCs, on day 5 and expression of CD80, CD86 and HLA-DR was the higher when FEECM are added to maturation factor. Functionally, when DCs matured in the presence of FEECM elicited stronger MLR, reduced phagocytic activity. These results support the use of the FEECM with MCM, TNF-α and poly (I–C) as maturation factor in DC generation that could result in functionally mature monocyte-derived DCs in comparison to either alone.  相似文献   
35.
Schwann cells (SCs), the supporting cells of the peripheral nerves, are indispensable for regenerating the peripheral and central nervous system. Copious preparation of these cells in a well-defined manner is to be a privileged position. SCs cultivation is overwhelmed by contaminating fibroblasts which are often outgrowing as the predominant cell type in an in vitro culture. This study introduces a technically simple and efficient procedure for SCs isolation and enrichment based on implementing recombinant and defined supplements. Collected adult rat sciatic nerves were cultured for 10 days as in vitro predegeneration. After dissociation and plating, the medium changed to knockout serum replacement supplemented DMDM/F12 medium containing various growth factors. The whole procedure took 3 weeks and SCs purity was then evaluated through implementing specific cytoplasmic and membranous markers. The viability of enriched SCs were evaluated by MTT assay. Within 10 days, over 99 % homogenous SCs were achieved and confirmed through immunofluorescence staining and flow-cytometry for P75NTR and S100 markers, respectively. MTT data revealed that the viability and metabolic activities of purified SCs were increased in expansion medium. This study provides a technically easy and efficient method with the benefits of not utilizing bovine serum or other animal products for SCs isolation and enrichment.  相似文献   
36.
37.
International Journal of Peptide Research and Therapeutics - Recently, peptide-based materials have been applied to solving many therapeutic problems and have shown particular efficacy as cancer...  相似文献   
38.
Length–weight parameters are presented for four endemic tooth‐carps of the genus Aphanius from Iran.  相似文献   
39.
Dillapiol was isolated from the essential oil of dill as a specific inhibitor of aflatoxin G1 production. It inhibited aflatoxin G1 production by Aspergillus parasiticus with an IC50 value of 0.15 microM without inhibiting aflatoxin B1 production or fungal growth. Apiol and myristicin, congeners of dillapiol, showed similar activity with IC50 values of 0.24 and 3.5 microM, respectively.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号