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951.
视觉运动信息的感知过程,包括从局域运动检测到对模式整体运动的感知过程.我们以蝇视觉系统的图形-背景相对运动分辨的神经回路网络为基本框架,采用初级运动检测器的六角形阵列作为输入层,构造了一种感知视觉运动信息的简化脑模型,模拟了运动信息应该神经计算模型各个层次上的处理.该模型对差分行为实验结果作出了正确预测.本文并对空间生理整合的神经机制作了讨论. 相似文献
952.
本文报导金发草属Pogonatherum Beauv.中1新种,即二芒金发草P.biaristatum S.L.Chen et G.Y.Sheng及觿茅属Dimeria R.Br.中2新种,即异花觿茅D.heterantha S.L.Chen et G.Y.Sheng及广西觿茅D.guangxiensis S.L.Chen et G.Y.Sheng. 相似文献
953.
Choi NS Kim BY Lee JY Yoon KS Han KY Kim SH 《Journal of biochemistry and molecular biology》2002,35(2):236-238
Based on the zymography analysis, Bacillus sp. DJ-4 (screened from Doen-Jang, a Korean traditional fermented food) secretes seven extracellular fibrinolytic enzymes (EFEs; 68, 64, 55, 45, 33, 27, and 13 kDa) in culture broth. These seven EFEs were analyzed by newly applied SDSfibrin zymography combined with gradient polyacrylamide (SDS-FZGP). This improved gel system was used with a 5-20% acrylamide gradient in a fibrin zymogram gel for the separation of proteins with molecular masses from below 10 kDa to over 100 kDa on one gel plate. Using this system, high molecular weight bands (HMWBs) were clearly and sharply resolved. We also examined the relationship between an acrylamide concentration and the enzymatic activity of EFE using densitometric analysis. 相似文献
954.
氯氟氰菊酯与阿维菌素增效混配制剂对美洲斑潜蝇的防治效果 总被引:3,自引:0,他引:3
低毒化学杀虫剂氯氟氰菊酯与生物源农药阿维菌素混配,通过其对美洲斑潜蝇室内毒力实验,测定共毒系数CTC为161~232,处于明显增效范围内。据此确定最佳配比,配制此增效混剂2%渗透型可湿性粉剂。在北京、山东两地防治美洲斑潜蝇幼虫的田间试验表明药效优良,制剂用量50 g/667m2药后3、7、11天两地区校正防效分别为85.26%~90.76%和86.74%~94.02%,制剂用量25g/667m2两地区相应防效分别为75.28%~85.17%、79.96%~88.68%。该增效混剂防治斑潜蝇速效性和持效性皆佳,成本有所下降,使用可湿粉与乳油相比较,可减少投放入环境的化学品数量,以减少环境污染。 相似文献
955.
956.
Background
Hypoxia-inducible factor 1α (HIF-1α) is an important regulator of immune and inflammatory responses. We hypothesized that nasal allergic inflammation is attenuated by HIF-1α inhibition and strengthened by HIF-1α stabilization.Objective
To elucidate the role of HIF-1α in a murine model of allergic rhinitis (AR).Methods
Mice were pretreated with the HIF-1α inhibitor 2-methoxyestradiol (2ME2) or the HIF-1α inducer cobalt chloride (CoCl2) in an established AR murine model using ovalbumin (OVA)-sensitized BALB/c mice. HIF-1α and vascular endothelial growth factor (VEGF) expression in nasal mucosa was measured and multiple parameters of allergic responses were evaluated.Results
HIF-1α and VEGF levels were locally up-regulated in nasal mucosa during AR. Inflammatory responses to OVA challenge, including nasal symptoms, inflammatory cell infiltration, eosinophil recruitment, up-regulation of T-helper type 2 cytokines in nasal lavage fluid, and serum OVA-specific IgE levels were present in the OVA-challenged mice. 2ME2 effectively inhibited HIF-1α and VEGF expression and attenuated the inflammatory responses. Stabilization of HIF-1α by CoCl2 facilitated nasal allergic inflammation. HIF-1α protein levels in nasal airways correlated with the severity of AR in mice.Conclusions
HIF-1α is intimately involved in the pathogenesis of nasal allergies, and the inhibition of HIF-1α may be useful as a novel therapeutic approach for AR. 相似文献957.
958.
杨树根系浸提液对3种牧草种子萌发及幼苗生长的影响 总被引:4,自引:0,他引:4
采用不同浓度(3、10和30mg/mL)的南林95杨〔PopulusdeltoidsBartr.cv.Lux×P.euramericana(Dode)Guineircv.I 45/51〕和NL 80351杨(P.deltoidsBartr.cv.Lux×P.deltoidsBartr.cv.Harvard)根系浸提液,处理杨树 牧草复合经营系统中3种主要牧草种子,探讨杨树根系浸提液对牧草种子萌发及幼苗生长的影响。结果表明:南林95杨和NL 80351杨根系浸提液对3种牧草种子的萌发及幼苗的生长有一定影响。这2个无性系根系浸提液对紫花苜蓿(MedicagosativaL.)、白三叶(TrifoliumrepensL.)和杂交狼尾草(PennisetumalopecuroidesL.×P.americanumL.)的种子发芽率、幼苗高生长、根长生长及种子活力主要表现为抑制作用,在浓度较高时影响尤为明显;但2个无性系根系浸提液对白三叶的高生长(南林95杨30mg/mL除外)表现出一定的促进作用;在3mg/mL浓度时,2个无性系根系浸提液对白三叶的种子活力也有一定的促进作用。 相似文献
959.
Cloned goats (Capra hircus) from adult ear cells 总被引:11,自引:0,他引:11
The average number of available oocytes recovered per ovary collected during the breeding season in dairy goats was 5.5 (1815/330). 66.17% (1201/1815) of oocytes extruded the first polar body after maturation in vitro for 20 h. 75.44% (906/1201) of matured oocytes with membrane evagination around the MII chromosomes were enucleated. Ear skin fibroblast cells were derived from an adult female dining Grey goat (C. hircus). The cells were cryopreserved in liquid nitrogen after passage 2. Thawed cells were further cultured for 3-6 passages and were subjected to serum starvation by 0.5% FBS for 2-10 d, then used as donor cells for nuclear transfer. 98.12% (889/906) of the enucleated oocytes were reconstructed by intracytoplasmic injection of karyoplast. The reconstructed embryos were activated by 5μ mol/L ionomycin for 4.5 min and further activated by culturing with 6-dimethylaminopurine (6-DMAP) for 3 h. After 36 h of culture in mCR1aaBF, 76.69% (645/841) of the cloned embryos cleaved. There were no signifi 相似文献
960.