诃子及其炮制品对CCl4诱导小鼠肝损伤的保护作用

将120只小鼠随机分为空白组、四氯化碳(CCl_4)组、联苯双酯(DDB)组及低、中、高3个剂量(1.0、2.0、4.0 g/kg)的原药诃子、白狼毒制诃子和茜草制诃子组,共12个组,每组10只。给药7 d后,腹腔注射10 m L/kgCCl_4油溶液,建立小鼠肝损伤模型,检测各组血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活力,肝脏超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH–Px)活力,观察肝脏组织学结构变化。研究结果显示,诃子不同炮制品可减少CCl_4所引起的小鼠肝损伤,显著降低血清ALT、AST活力,提高肝脏SOD、GSH–Px活力,并对肝细胞有一定保护作用;药效表现由强到弱依次为茜草制诃子、白狼毒制诃子、生药诃子,且高剂量的效果优于低剂量。以茜草制诃子高剂量组4.0 g/kg效果最为理想,其作用机制可能与抗氧化性有关。     

3,3-二甲基-2-(1,2,4-三唑-1-基)甲基-1-氨基-2-丁醇的合成

用３,３－二甲基－１－（１,２,４－三唑－１－基）－２－丁酮为原料,经４步反应,合成了未见文献报道的化合物３,３－二甲基－２－（１,２,４－三唑－１－基）甲基－１－氨基－２－丁醇,其结构经ＩＲ,１ＨＮＭＲ及元素分析予以确证。     

Effects of four feeding stimulants in high plant‐based diets on feed intake,growth performance,serum biochemical parameters,digestive enzyme activities and appetite‐related genes expression of juvenile GIFT tilapia (Oreochromis sp.)

The present research evaluated the effects of four feeding stimulants on feed intake (FI), growth performance, body composition, serum biochemical parameters, digestive enzyme activities and appetite‐related gene expression for juvenile GIFT tilapia. Five experimental high plant‐based diets (with 0, 0.4 g kg^?1 dimethyl‐β‐propiothetin (DMPT), 0.6 g kg^?1 dimethylthetin (DMT), 1.8 g kg^?1 tryptophan (Trp) and 6 g kg^?1 betaine (Bet), respectively supplemented) were fed to juvenile GIFT tilapia (Oreochromis sp.) (3.34 ± 0.01 g) for 8 weeks. The results showed that FI was significantly increased by Trp and DMT. The highest specific growth rate (SGR) and protein efficiency ratio (PER) was observed for fish fed Bet diet, followed by DMT. Serum triglyceride was significantly increased by DMPT. Fish fed Bet diet showed significantly higher intestinal protease, liver protease and intestinal amylase activities. The neuropeptide Y (NPY) mRNA expression in brain was significantly improved by Trp, and ghrelin mRNA expression in stomach was significantly increased by DMT. It is concluded that supplementation of Trp or DMT could act as an effective feeding stimulants (FS) in high plant‐based diets for juvenile GIFT tilapia, which might be associated with the relatively higher orexigenic (NPY or ghrelin) genes expression, and supplementation of Bet could improve SGR, PER and reduce feed conversion ratio (FCR) of juvenile GIFT tilapia.     

Fatty acid and wax biosynthesis in susceptible and triallate-resistant Avena fatua L.

The recent characterization of triallate-resistant lines of wild oat (Avena fatua L.) deficient in triallate sulfoxidation provides an experimental system to investigate and differentiate the effects of triallate and triallate sulfoxide on wax and lipid biosynthesis. Greenhouse applications of triallate dramatically reduced epicuticular wax deposition in susceptible (S) but not resistant (R) wild oats. Triallate treatment had no effect on in-vivo concentrations of C₁₂ to C₂₆ fatty acids and fatty alcohols in R plants, while elongated fatty acid fractions (C>18) were significantly reduced in S plants. In contrast, treatment with triallate sulfoxide reduced in-vivo concentrations of elongated fatty acids equally in R and S, supporting the hypothesis that triallate sulfoxide is more inhibitory than triallate towards fatty acid elongases. Although de-novo synthesis of short-chain fatty acids was not affected by triallate or triallate sulfoxide in R or S plants, synthesis of elongated fatty acid fractions was dramatically reduced in S plants by triallate. Fatty acid biosynthesis in R and S plants was equally sensitive to triallate sulfoxide. The results support the idea that in-vivo triallate sulfoxidation is necessary for herbicidal activity, and confirm that reduced rates of triallate sulfoxidation confer resistance in R wild oats. © 1997 SCI.     

阿维菌素复方缓释制剂在绵羊寄生虫病防治中的应用

选择伊维菌素-丙硫咪唑复方片剂、伊维菌素-丙硫咪唑亚砜注射液和阿维菌素-丙硫咪唑亚砜复方长效油胶,对新疆阿克苏一群未进行驱虫和药浴的当年生羔羊进行试验。结果表明,复方片剂、伊维菌素-丙硫咪唑亚砜注射剂和阿维菌素-丙硫咪唑亚砜长效油胶在用药以后7 d就可以100%地杀灭发病绵羊的多种体内外寄生虫,第25天绵羊痒螨病的临床症状均已缓解或消除,并开始生长新毛。用药后40 d复方片剂组就出现了再感染现象,而阿维菌素-丙硫咪唑亚砜长效油胶组,维持100 d左右才出现肠道线虫感染,感染率为80%,但感染强度只是复方片剂组的10%,对绵羊疥癣可基本控制。     

稀释气体对二甲醚着火延迟特性的影响

在上止点压力1.5 MPa,上止点温度670~795 K,当量比为1的实验条件下,利用快速压缩机(RCM)研究了N_2、N_2/Ar(50%/50%)和Ar/CO_2(61.2%/38.8%)稀释气体对二甲醚(DME)着火延迟期的影响。利用CHMKINPRO软件在较大温度范围内进行了模拟研究。结果表明:不同稀释气体组分对二甲醚混合气体第一阶段着火延迟期影响很小,但对总着火延迟期具有较大的影响,尤其在负温度系数(NTC)区间的起点温度附近。与N_2相比,N_2/Ar(50%/50%)使得实验中总着火延迟期缩短30%。稀释气体的化学效应对第一阶段着火延迟期和总着火延迟期的影响均很小。在低温区间和NTC区间,稀释气体的热效应起主导作用,而当上止点温度超过NTC区间时,CO_2的化学效应影响增强且超过热效应而起到主导作用。随稀释率增加,DME混合气体第一阶段着火延迟期略有延长,而总着火延迟期出现明显延长,且总着火延迟期的NTC现象变得更加明显。     

基于感官组学分析玉米香型南川大茶树工夫红茶特征香气

南川茶是重庆市南川区特有的古茶树资源,具有较高的开发利用价值。采用顶空固相微萃取结合气相色谱-质谱联用技术（HS-SPME-GC/MS）、气相色谱-嗅闻分析技术（GC-O）以及通过计算香气活度值（OAV）与香气特征影响值（ACI）,对南川大茶树鲜叶制成的玉米香型工夫红茶香气特征进行分析。结果表明,玉米香型工夫红茶中OAV>1的挥发性化合物有22种,其中二甲基硫的OAV最高（1 187.32）,其ACI达51.56%,远高于其他化合物。GC-O嗅闻到26种活性香气化合物,其中二甲基硫的嗅闻强度较高（4.75）,并呈现出玉米香属性。香气重组与删除试验进一步验证了二甲基硫对于玉米香型工夫红茶的重要性。本研究明确了玉米香型南川大茶树工夫红茶的特征香气成分,为南川大茶树工夫红茶品质的定向调控提供一定理论依据。     

龙竹半纤维素的提取分离及结构表征

龙竹竹粉经脱蜡及脱淀粉后,再经亚氯酸钠脱木素制得综纤维素,进一步用二甲亚砜(DMSO)以及KOH溶液提取,经乙醇沉淀后制得半纤维素H1和H2,得率分别为18.7%和39.8%。对半纤维素组分H1和H2进行糖分析、红外光谱以及核磁共振分析。结果表明,龙竹半纤维素为乙酰化的L-阿拉伯糖基-4-O-甲基葡萄糖醛酸木聚糖,其中阿拉伯糖连接在木聚糖主链的C-3位,4-O-甲基葡萄糖醛酸连接在木聚糖主链的C-2位,而乙酰基连接在木聚糖主链的C-2位或C-3位。