三倍体毛白杨及杉木苯酚液化物的结构分析

为搞清酸性条件下三倍体毛白杨和杉木苯酚液化物的结构,该研究对两种木材分别进行了液化处理,并对液化物进行了傅立叶转换红外光谱（FTIR）、核磁共振光谱（1H-NMR、13C-NMR和31P-NMR）以及电子扫描电镜（SEM）的测定分析.FTIR和NMR的分析结果表明,液化后的毛白杨和杉木均发生了结构上的明显变化,出现了纤维素和木素的基本活性结构单元,表明液化处理使木材发生了降解、酚化等化学反应.SEM测定结果表明,木材液化物中含有未完全液化的微小木材组织碎片,两种木材液化物中残存的这种物质的大小存在差异.      

苹果中多酚含量测定与比较

以红富士苹果为原料,对苹果果实发育过程中总酚、绿原酸、黄烷醇、原花色素含量进行测定。结果表明,多酚物质总量在果实发育早期有一个上升过程,然后逐渐减少,后期变缓,同时果肉中绿原酸含量的比例逐渐下降;而黄烷醇和原花色素所占比例则呈上升趋势。在成熟果实的不同部位,多酚含量分布也明显不同。     

The phenol red thread tear test in large Psittaciformes

OBJECTIVE: To develop a standard method for measuring tear production in large Psittaciformes using the phenol red thread (PRT) tear test. To establish mean PRT tear test values in clinically normal pet birds and to assess the reproducibility of the test. ANIMALS: Two geographically distinct populations of healthy, large Psittaciformes (pilot study and study population). Species groups include: cockatoo (17), macaw (22), Amazon (10), African gray (1), eclectus (1) and pionus (1). PROCEDURE: The PRT was placed under the upper eyelid and both eyelids were held closed throughout the test. The PRT tear test was repeated after 2 months in the pilot study and after approximately 5 min in the study population. RESULTS: The mean PRT tear test values for the pilot study were OD=28.2 mm/15 s (+/- 6.3 mm), OS=24.1 mm/15 s (+/- 6.6 mm) and OD=25.4 mm/15 s (+/- 3.3 mm), OS=25.5 mm/15 s (+/- 5.2 mm), for the first and second visits respectively. The mean PRT tear test value for the study population was: OD=19.8 mm/15 s (+/- 4.3 mm), OS=20.1 (+/- 3.9 mm) and OD=20.0 mm/15 s (+/- 4.5 mm), OS=19.1 mm/15 s (+/- 3.3 mm), for the first and second tests respectively. There was poor repeatability between tests. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the PRT tear test is a practical method for measuring tear production in large Psittaciformes, although adaptations to the established diagnostic method are necessary to overcome some anatomical differences present in birds. Good reproducibility of the PRT tear test could not be demonstrated in a clinically normal population of birds but geographic location appears to significantly influence results.     

一种适于PCR扩增的快速提取猪基因组DNA的碱裂解法

以大白猪背最长肌、脾脏、耳组织为材料,用碱裂解法和酚-氯仿法分别提取猪基因组DNA,用紫外分光光度计、琼脂糖凝胶电泳、PCR扩增检测DNA的产量和质量,结果发现2种方法提取的DNA产量没有明显差异。通过猪MC4R、TEF-1基因特异引物进行PCR扩增均能得到目的条带。碱裂解法提取的DNA原液稀释5倍、10倍后作为模板均获得了较为稳定的扩增产物。该结果表明,简单、快速、无毒的碱裂解法适用于动物定性PCR检测时DNA的提取。     

避免疫苗中有色物质干扰的甲醛残留量测定法

建立一种能有效避免疫苗中有色物质干扰的甲醛残留量测定法。采用乙酰丙酮分光光度法,利用“本底扣除”的方式,在410nm波长处对疫苗中甲醛的残留量进行测定。结果,酚红、中性红等有色物质均不会对测定结果产生干扰;在0.002~0.2mg/ml的范围内,吸光度与浓度呈良好的线性关系(r=0.9999,n=7);在0.005mg/ml、0.05mg/ml和0.15mg/ml三种添加浓度下,该方法的平均回收率分别为108.6%、97.5%和101.3%;对24批含有有色物质的疫苗进行测定,所得结果与专属性较强的HPLC法一致。该方法专属性强、准确度好、适用范围宽,可以作为疫苗中甲醛残留量的检测方法。     

Preference of goats (Capra hircus L.) for tanniniferous browse species available in semi‐arid areas in Ethiopia

The objectives were to determine browse species preference of goats using dry matter intake (DMI) as a proxy, to compare preference when offered in combination with polyethylene glycol (PEG) and to establish relationships between browse species intake and chemical compositional data. Air‐dried leaves of Acacia etbaica, Cadaba farinosa, Capparis tomentosa, Dichrostachys cinerea, Dodonaea angustifolia, Euclea racemosa, Maerua angolensis, Maytenus senegalensis, Rhus natalensis and Senna singueana were used. Two cafeteria trials, each lasting 10 days, were conducted using four local mature male goats of 2–2.5 years receiving a daily ration of grass hay (4% of body weight) and 200 g wheat bran. In trial 1, goats were offered 25 g of each browse species for a total of 30 min with intake, time spent on consumption and the number of visits to specific browse species recorded at 10‐min intervals. In trial 2, the same procedure was followed except that 25 g of PEG 4000 was added to the daily wheat bran ration. Crude protein and neutral detergent fibre in browse species ranged from 69.0–245.5 to 159.8–560.6 g/kg dry matter (DM) respectively. Total phenols and total tannins contents ranged between 3.7–70.6 and 2.5–68.1 mg tannic acid equivalent/g DM, respectively, and condensed tannins 1.7–18.4 Abs_550 nm/g DM. Preference indicators measured in the first 10 min of browse species intake differed significantly among browse species and with PEG (p < 0.0001). Principal components explained 69.9% of the total variation in browse species DMI. Despite the high tannin levels, D. cinerea, R. natalensis and A. etbaica were the most preferred species regardless of PEG presence. Tannin levels at the observed browse species DMI did not determine preference, instead, preference appeared to be based on hemicellulose. Determining browse species preference is essential to exploit them to improve nutrient utilization and control parasites in goats.     

BS-12+CTMAB复配修饰黄棕壤对菲的吸附

为了探究两性阳离子复配修饰黄棕壤对菲的吸附效应及影响机制,基于两性修饰剂十二烷基二甲基甜菜碱(BS-12)和阳离子型表面修饰剂十六烷基三甲基溴化铵(CTMAB)复配修饰膨润土吸附苯酚的最佳修饰比例,分别以蒙脱石含量为43%和6%的2种黄棕壤制备了2个系列的BS-12+CTMAB复配修饰土样。通过批处理法研究了两性复配修饰黄棕壤对菲的吸附特征,分析了温度、pH值和离子强度对复配修饰黄棕壤吸附菲的影响,并探讨了复配修饰黄棕壤对菲的吸附机理。结果表明,随着总修饰比例的增大,2种复配修饰黄棕壤对菲的吸附能力均逐渐增强,Henry模型适合描述2种复配修饰黄棕壤对菲的吸附;2种修饰黄棕壤对菲吸附量均随温度、pH值的升高而降低,在低浓度范围内,随离子强度的增大而升高;2种复配修饰黄棕壤对菲的吸附均以分配吸附为主,总体上修饰黄棕壤对菲和苯酚的吸附具有相似的机制。土样阳离子交换量(CEC)和修饰比例是两性复配修饰黄棕壤吸附菲的决定因素。     

Comparison of organic and conventional farming for onion yield,biochemical quality,soil organic carbon,and microbial population

In an ongoing field experiment, organic and conventional farming (control) were compared for onion bulb yield, biochemical quality, soil organic carbon (SOC), and microbial activity after the sixth cropping cycle. The treatments used for organic production were farmyard manure (FYM, 20,000 kg ha^?1), poultry manure (PM, 10,000 kg ha^?1), vermicompost (VC, 10,000 kg ha^?1), neem cake (NC, 5000 kg ha^?1), and a combination of FYM (5000 kg ha^?1), PM (2500 kg ha^?1), VC (2500 kg ha^?1), and NC (1250 kg ha^?1); all treatments were compared with the control. Organic treatments produced 24.6–43.6% lower yield consistently for 6 years than the control treatment. No significant difference was observed between PM, FYM, and VC treatments for the bulb yield. Bulb analysis during the sixth year indicated that plants that received FYM, PM, or VC had higher levels of total phenol, total flavonoid, ascorbic acid, and quercetin-3-glucoside than the control plants. All the five organically treated sets had significantly higher values of SOC, microbial population, fungal-to-bacterial ratio, and dehydrogenase activity than the control and the initial values in each treated set. The results indicate that FYM, PM, or VC application enhances biochemical quality and organic farming is more sustainable than conventional farming.     

明胶酶解物捕获甲醛工艺的优化及其应用

为控制鱿鱼丝制品中的甲醛含量,以食用明胶酶解物为甲醛捕获剂,采用响应面法对捕获条件进行优化,并将明胶酶解物运用到秘鲁鱿鱼丝加工中,改良生产工艺,降低鱿鱼丝制品甲醛含量。结果表明,p H、温度、时间对明胶酶解物的甲醛捕获率均有显著影响,明胶酶解物捕获甲醛的最佳条件为:温度94.04℃,时间87.04 min,p H值8.99,明胶酶解物浓度1%,该条件下甲醛捕获率达94.12%。在鱿鱼丝加工中,蒸煮前将鱿鱼片浸泡在含1%明胶酶解物的溶液(料液比1∶3)中6 h,制得的鱿鱼丝成品甲醛含量为7.49 mg·kg~(-1),极显著低于原工艺组鱿鱼丝甲醛含量(13.21 mg·kg~(-1)),且对鱿鱼丝的口味和色泽无影响。综上,明胶酶解物具有较好的甲醛捕获能力,能抑制鱿鱼丝加工中甲醛的产生。本试验结果为生产食用安全的鱿鱼丝提供了指导。     

蝗虫取食对毛花雀稗防御酶活性的影响

防御酶是植物对昆虫危害的潜在防御机制。毛花雀稗(Paspalum dilatatum)作为一种优良牧草，了解被昆虫取食胁迫后其防御酶的变化很有必要。为此，本研究分析了蝗虫(Oxya chinensis)取食毛花雀稗0 (CK)、24、48、72和96 h后毛花雀稗总抗氧化能力(total antioxidant capacity, T-AOC)、过氧化物酶(peroxidase, POD)、过氧化氢酶(catalase, CAT)、超氧化物歧化酶(superoxide dismutase, SOD)、酪氨酸解氨酶(tyrosine ammonia-lyase, TAL)、多酚氧化酶(polyphenol oxidase, PPO)、脂氧合酶(lipoxygenase, LOX)、谷胱甘肽S-转移酶(glutathione S-transferase, GST)、苯丙氨酸解氨酶(phenylalanine ammonia-lyase, PAL)活性及植物总酚(total phenols, TP)含量的变化规律。结果表明：与不取食对照相比，蝗虫取食后毛花雀稗植株中POD、CAT、LOX、PPO、TAL、GST活性以及TP含量均在部分取食时间或所有取食时间显著升高(P < 0.05)。其中T-AOC在24 h时显著升高(P < 0.05)；TAL、PPO和GST活性均随取食时间的延长呈先升高后降低的变化趋势，分别在48、72和24 h时达到最高，是对照的3.71、2.10和21.25倍。相反，除24 h时SOD活性外，SOD、PAL活性在蝗虫取食胁迫下均显著降低(P < 0.05)。可见，POD、CAT、PPO、TAL、GST和LOX等防御酶在毛花雀稗防御害虫胁迫中发挥了非常重要的保护作用。