Improvement of anther culture methods for doubled haploid production in barley breeding

There is potential to accelerate cultivar development with a doubled haploid system for breeding line production. Anther culture methodology was evaluated for U.S.A. spring barley (Hordeum vulgare L.) breeding applications. Gelrite was found to be an acceptable replacement for ficoll in the induction medium to reduce costs while maintaining embryoid and plant production levels. Beneficial effects of 28 d cold pretreatment of donor spikes for anther culture were confirmed with Pacific Northwest USA barley genotypes. A 3 d mannitol solution pretreatment of fresh anthers was shown to be less effective for green plant production compared to 28 d cold pretreatment of donor spikes. Extended donor spike cold pretreatment from 28 to 42 d did not reduce anther culture productivity. Based on this research, anther culture techniques show promise for economical and convenient application in spring barley breeding.Abbreviations DH doubled haploid - LS Linsmaier and Skoog basal medium - BAP benzylaminopurine - GLM Generalized Linear Model - SAS Statistical Analysis System     

Electrospun Scaffold of Collagen and Polycaprolactone Containing ZnO Quantum Dots for Skin Wound Regeneration

Nanofibers(NFs)have been widely used in tissue engineering such as wound healing.In this work,the antibacterial ZnO quantum dots(ZnO QDs)have been incorporated into the biocompatible poly(ε-caprolactone)/collagen(PCL/Col)fibrous scaffolds for wound healing.The as-fabricated PCL-Col/ZnO fibrous scaffolds exhibited good swelling,antibacterial activity,and biodegradation behaviors,which were beneficial for the applications as a wound dressing.Moreover,the PCL-Col/ZnO fibrous scaffolds showed excellent cytocompatibility for promoting cell proliferation.The resultant PCL-Col/ZnO fibrous scaffolds containing vascular endothelial growth factor(VEGF)also exhibited promoted wound-healing effect through promoting expression of transforming growth factor-β(TGF-β)and the vascular factor(CD31)in tissues in the early stages of wound healing.This new electrospun fibrous scaffolds with wound-healing promotion and antibacterial property should be convenient for treating wound healing.     

基因组规模代谢网络模型构建及其应用

微生物制造产业的发展迫切需要进一步提高认识、设计和改造微生物细胞代谢的能力,以推动工业生物技术快速发展。随着微生物全基因组序列等高通量数据的不断积聚和生物信息学策略的持续涌现,使全局性、系统化地解析、设计、调控微生物生理代谢功能成为可能。而基于基因组序列注释和详细生化信息整合的基因组规模代谢网络模型(GSMM)构建为全局理解和理性调控微生物生理代谢功能提供了最佳平台。以下在详述GSMM的应用基础上,描述了如何构建一个高精确度的GSMM,并展望了未来的发展方向。     

Enhanced production of Penicillium expansum PED-03 lipase through control of culture conditions and application of the crude enzyme in kinetic resolution of racemic Allethrolone

Alkaline lipase production was performed in submerged fermentation by Penicillium expansum PED-03. It was found that the suitable carbon source and nitrogen source for lipase production were 0.5% starch and 4.0% soybean meal, respectively. The maximal lipase activity (850 U/mL) of production was achieved at initial pH 5.5-6.0, 26 degrees C, 72 h. Tween-80 was an effective enhancer for lipase production. Agitation speed of the fermentor played an important role, and the suitable agitation speed for lipase production was 500 r/min. The lipase was stable within the range of pH 7.0-10.0 and 20-40 degrees C, and the optimum conditions for the enzymatic reaction were 35 degrees C and pH 9.5. The enzymatic resolution of racemic allethrolone (4-hydroxy-3-methyl-2-(2-propenyl)-2- cyclopenten-1-one) was carried out by the lipase from P. expansum PED-03, and the conversion reached 48% with excellent enantioselectivity (E > 100), which showed a good application potential in the production of optically pure allethrolone.     

KfoE encodes a fructosyltransferase involved in capsular polysaccharide biosynthesis in Escherichia coli K4

Escherichia coli K4 synthesizes a capsular polysaccharide (CPS) consisting of a fructose-branched chondroitin (GalNAc-GlcA(fructose)n), which is a biosynthetic precursor of chondroitin sulfate. Here, the role of kfoE in the modification of the chondroitin backbone was investigated using knock-out and recombinant complementation experiments. kfoE disruption and complementation had no significant effect on cell growth. CPS production was increased by 15 % in the knock-out strain, and decreased by 21 % in the knock-out strain complemented with recombinant kfoE. CPS extracted from the knock-out strain was chondroitin, whereas CPS extracted from the complemented strain was a fructose-branched chondroitin. The results demonstrated that the kfoE gene product altered the fructose group at the C3 position of the GlcA residue during production of K4CPS.     

18S rDNA的研究进展及其在膜翅目昆虫分子系统学中的应用

本文综述了18S rDNA的研究进展,主要包括了18S rDNA的结构研究,18S rDNA的网络资源利用和18S rDNA在膜翅目昆虫中的应用。     

术中静脉不向剂量右美托咪啶对全髋置换术患者术后患者芬太尼静脉自控镇痛效果的影响

目的：观察气管内全身麻醉下行全髋置换术患者,术中静脉应用不同剂量右美托咪定对术后芬太尼静脉自控镇痛效果的影响及相关不良反应发生的情况。方法：选择择期在气管内全麻下行全髋置换术的患者60 例,ASA Ⅰ ～Ⅱ级,年龄47～78 岁,体重42～79 kg。患者随机分组法分为3 组（n=20）：C 组（盐水对照组）、D1 组（右美托咪定0.5 μg/kg 组）和D2 组（右美托咪定1 μg/kg组）,在手术结束前约1 小时按分组分别给予生理盐水和右美托咪啶,术后镇痛使用芬太尼静脉自控镇痛24 h。记录患者术后2h、2～6 h、6～12 h、12～24 h芬太尼的用量;VAS 评分法评估患者术前、术后2 h、6 h、12 h、24 h 时的疼痛程度;记录镇痛期间恶心呕吐、皮肤瘙痒及过度镇静等不良反应发生的情况。结果：术后2h 和术后2～6 h芬太尼用量D1组和D2 组较C 组减少（P＜0.05）,但D1组和D2 组之间比较无差异（P＞0.05）;而术后6～12 和12～24 h三组患者芬太尼用量无差异（P＞0.05）。术后2 h、2～6 hVAS评分D1 组和D2 组较C组减少（P＜0.05）,而D1组和D2 组之间比较无差异（P＞0.05）;术后6～12、12～24 h三组患者VAS 评分无差异（P＞0.05）。与C 组比较,D1 组和D2 组镇痛期间恶心呕吐发生率降低（P＜0.05）,余不良反应各组之间比较无差异（P＞0.05）。结论：气管内全身麻醉下行全髋置换术的患者,术中静脉应用右美托咪啶可在术后6 h内增强芬太尼镇痛的效果减少芬太尼的用量,但增大剂量效果并不增加而作用时间也不延长。