超声波法提取黄芪多糖的工艺研究

超声波法提取黄芪多糖.单因素试验考察了提取时间、料液比、温度、pH值时黄芪多糖提取率的影响,并通过正交试验优化了提取黄芪多糖的工艺条件.结果表明,超声波法提取黄芪多糖的最佳条件为时间20 min/次,提取次数2次,料液比1:12,pH值9,温度80℃,黄芪多糖的提取率高达96.6%.该方法具有节省溶剂、省时、节能及提取率高等优点.     

白车轴草多糖提取工艺的研究

本试验采取热水浸提法提取白车轴草多糖,研究其最佳提取工艺.以白车轴草为原料,多糖提取得率为指标,分别对4个提取参数:浸提温度、料液比、浸提时间和浸提液pH值进行了单因素试验;然后对上述4个因素采用L9(34)正交试验进行优化.结果表明,白车轴草多糖提取得率随着温度的升高而提高,在100℃时达到最大;料液比、浸提时间和浸提液pH值对多糖得率的影响为单峰曲线,上述条件分别为1:15、4 h和8时多糖得率最高.pH值、料液比、温度和提取时间对白车轴草多糖得率的影响都存在极显著差异(P＜0.001),影响多糖得率的各因素主次关系为:pH值＞料液比＞温度＞提取时间,浸提液pH值对白车轴草多糖得率的影响最大.白车轴草多糖的最佳提取工艺参数为:提取时间5 h,料液比1:15,温度100℃,浸提液pH值为9.经验证试验测得,此条件下白车轴草多糖得率为2.26%.试验结果揭示,白车轴草多糖的提取得率受提取工艺(浸提温度、料液比、浸提时间和浸提液pH值)的影响显著,调整提取工艺可获得更高的多糖得率.     

白三叶叶蛋白提取及纯化工艺

以白三叶（Trifolium repens）为材料探讨了叶蛋白的提取工艺和纯化方法。对白三叶叶蛋白提取中加热时间、温度、pH值、料液比、酸的种类等单因素以及纯化试剂甲醇、乙醇、丙酮、四氯化碳、水等进行了研究。结果表明,各单因素最佳参数为加热时间9 min,温度90 ℃,pH值 4.0,料液比1∶2,沉淀的酸为硝酸。对加热时间、加热温度、pH值和料液比进行4因素3水平正交试验,发现影响叶蛋白提取因素为pH值>温度>时间>料液比,最佳提取工艺为加热时间9 min,温度80 ℃,pH值4.0,料液比1∶2。对叶蛋白纯化结果表明,纯化剂对叶蛋白纯度的影响依次为甲醇>乙醇>丙酮>四氯化碳>水,但各种纯化剂之间差异不显著（P>0.05）。     

三种药用植物多糖的提取工艺研究

为了比较不同提取方法对白芷、白及和桔梗多糖提取率的影响,试验采用热水浸提法和微波提取法提取三种植物多糖,并以多糖提取率为测量指标进行比较。结果表明:白芷水提最佳提取工艺为浸提时间2 h,料水比1∶12,浸提温度40℃;白芷微波最佳提取工艺为功率400 W,料水比1∶15,时间8 min。白及水提最佳提取工艺为浸提时间2 h,浸提温度30℃,料水比1∶40;白及微波最佳提取工艺为时间8 min,料水比1∶30,功率640 W。桔梗水提最佳工艺为浸提时间4 h,料水比1∶20,浸提温度40℃;桔梗微波提取最佳工艺为时间4 min,料水比1∶40,功率240 W。此外,微波提取法提取的多糖提取率高于热水浸提法,同时三种药用植物中微波法提取的白及多糖提取率最高,为38.67%。     

正交设计优化黄芪多糖提取工艺

[目的]优化黄芪多糖的提取工艺。[方法]以料液比、提取时间、提取次数、浸泡时间为试验因素,各因素分别设计3个水平,采用L_9（3~4）正交设计,以黄芪多糖含量为考察指标,优选黄芪多糖的水回流提取工艺。[结果]最佳提取工艺条件为：料液比1∶12,提取时间1.0 h,浸泡时间1.0 h,提取次数3次。在最佳提取工艺条件下,黄芪多糖含量占原药材的6.4%,多糖含量占粗多糖的58.23%。[结论]优化后的提取工艺操作简便、快捷,重复性、稳定性良好。     

超声波-微波联合辅助提取澳洲坚果青皮多糖工艺优化及其抗氧化活性

研究分析了澳洲坚果不同果实部位的多糖提取率。以澳洲坚果青皮为原料,采用超声波-微波联合辅助法提取多糖,运用单因素实验与正交实验考察了微波功率、提取时间、料液比、超声温度4个因素对多糖提取率的影响,研究其最优提取条件。以VC为对照,通过测定澳洲坚果青皮多糖清除1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）、羟基自由基的能力与还原力评价其抗氧化活性。结果表明：澳洲坚果不同果实部位中,青皮的多糖提取率最高。澳洲坚果青皮多糖超声波-微波联合辅助提取工艺中各因素对提取率的影响力排序为提取时间>料液比>超声温度>微波功率,且其均达到了极显著水平（P＜0.01）,最佳提取工艺条件为：提取时间90 min、超声温度65 ℃、料液比1:25（g/mL）、微波功率400 W,在此条件下提取率达到1.96%。澳洲坚果青皮多糖的抗氧化活性与质量浓度呈良好的极显著正相关（P＜0.01）,相关系数R分别为0.9707、0.9813、0.9912,具有较强的DPPH、羟基自由基清除能力和较高的还原力,其半抑制浓度（half maximal inhibitory concentration,IC50）分别为38.55、20.38、41.51 μg/mL,相同浓度下略低于VC。研究结果为澳洲坚果青皮的综合利用和青皮多糖产品的进一步开发提供一定的理论依据。     

蒲公英中黄酮的响应面法优化提取和同步荧光法检测研究

本试验应用响应面法优化超声-微波协同萃取蒲公英中黄酮的提取工艺，并建立测定黄酮含量的同步荧光法。在单因素试验结果的基础上，以提取溶剂乙醇浓度、微波功率、萃取时间和料液比为自变量，提取液的荧光强度为响应值，设计4因素3水平响应面试验，优化蒲公英中黄酮的提取工艺；单因素试验确定同步荧光法的测定条件。结果表明：1)判定系数R²=0.964 8,说明模型与实际结果拟合程度好，所得模型能解释96.48%的响应值改变，校正判定系数(R_Adj²=0.929 5)与预测判定系数(R_Pred²=0.886 0)接近。2)响应面法优化超声-微波协同萃取技术提取蒲公英中的黄酮，其最佳提取条件为乙醇浓度50%,微波功率250 W,萃取时间30 min,料液比1∶30 (g∶mL)。3)同步荧光法的最佳测定条件为波长差值(Δλ)=55 nm, Al(NO₃)₃浓度0.2%,加入pH=6的醋酸-醋酸钠缓冲液1 mL,室温条件下反应50 min。在最佳测定条件下，...     

微波辅助酸法提取菜籽粕多糖的工艺条件优化及其性质研究

试验采用微波辅助酸法提取菜籽粕多糖。在正交试验的基础上通过Box-Behnken中心组合进行三因素三水平试验,对多糖的提取工艺进行优化。结果表明:最佳提取工艺为盐酸浓度0.3 mol/L、微波功率200 W、微波时间8 min、料液比1∶26(g/mL)、微波温度63℃,在此条件下,菜籽粕多糖的提取率达3.1763%。多糖的性质研究结果表明:菜籽粕多糖有一定的清除羟自由基能力,最大清除率达85.79%;Fe3+和Co2+对多糖稳定性影响较大,在配制饲料时应避免直接接触。     

二次回归正交优化微波辅助提取杏鲍菇多糖工艺条件研究

本实验以苯酚-浓硫酸法测定多糖,采用微波辅助热水浸提杏鲍菇子实体粗多糖,在单因素实验基础上,根据Box-Behnken中心组合试验设计原理,进行四因素三水平二次回归正交试验,依据二次回归线性分析确定各工艺条件的影响因素。结果表明:杏鲍菇子实体多糖提取的最优工艺条件为:提取温度75.56℃、提取时间11.98min、料液比1:34.81、微波功率400.52W,在此最优工艺条件下杏鲍菇多糖的得率可达7.426%。     

荷花蜂花粉多糖提取条件的研究

采用温浸法,在单因素试验基础上设计4因素3水平正交试验,确定荷花蜂花粉多糖最佳提取工艺条件,采用苯酚-硫酸法检测多糖含量。结果表明:4因素对荷花蜂花粉多糖提取的影响顺序为提取次数>提取温度>料液比>提取时间;荷花蜂花粉多糖提取的最优条件为1:8的料液比,50℃水浴条件下,浸提3h。考虑到经济效益和成本因素,经两次提取后荷花蜂花粉多糖的提取率就可以达到99%,故最佳提取次数为两次。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in