柚皮中黄酮物质的提取工艺研究

研究了黄酮物质的最佳提取工艺以及提取过程中影响得率的因素。通过单因素和正交试验对提取工艺参数进行分析,结果显示,黄酮得率的影响因素由大到小依次为:固液比乙醇浓度提取温度提取时间,最佳工艺条件为固液比1∶20,乙醇浓度85%,提取温度75℃,提取时间3.0 h,在此条件下所得柚皮黄酮得率为0.536%。     

新会陈皮中黄酮类化合物提取工艺的研究

以水和乙醇溶液为提取介质分别提取了新会陈皮中的黄酮类化合物,通过单因素试验和正交试验验确定了提取新会陈皮黄酮类化合物的最佳工艺条件.结果表明:乙醇作为新会陈皮黄酮类化合物提取介质的提取效果明显优于纯水;采用乙醇作为提取溶剂时,影响新会陈皮中黄酮类化合物提取率的因素由大到小依次为乙醇浓度>液料比>提取时间>提取温度;最佳工艺条件为乙醇浓度80%、液料比1:45、温度70℃、提取时间3 h,最佳提取T艺的新会陈皮黄酮得率为0.80%,此外,罗岗橙皮、梅州蜜柚皮、芦柑皮采用最佳工艺提取的黄酮含量分别为0.94%、0.30%和1.19%.     

柚子皮中总黄酮的提取工艺研究

本文对柚子皮中总黄酮的最佳提取工艺以及提取过程中影响得率的因素进行了研究。根据实验结果,最佳工艺条件为固液比1∶20,温度80℃,乙醇浓度50%,提取时间2 h,实验中柚皮总黄酮得率为0.625%。     

微波法从柚皮中提取黄酮类化合物的工艺研究

应用微波法,通过单因素试验和正交试验对柚皮中黄酮类化合物提取工艺进行了研究。结果表明,用微波法从柚皮中提取黄酮的最佳工艺条件为:乙醇浓度80%、浸提时间5 m in、料液比1∶25。此时黄酮得率为0.884 mg/g。与传统水浴法的对比试验表明:微波法不仅节省时间,而且提取效率高,是一种快速、高效、节能的新型提取工艺。     

柚皮中柚皮苷的超声波辅助提取条件研究

【目的】探讨超声波辅助提取柚皮中柚皮苷的优化工艺条件。【方法】通过单因素试验考察了提取温度、提取时间、固液比、乙醇体积分数及提取功率5个因素对柚皮苷提取率的影响,并在此基础上用正交试验进行工艺参数的优化。【结果】当提取时间为1 h时,超声波辅助提取柚皮苷的较优工艺条件为:提取温度50℃,固液比1∶30,乙醇体积分数50%,提取功率25 W。【结论】在试验所得优化工艺条件下柚皮苷提取率为5.437%。     

毛竹笋总黄酮的提取工艺研究

以毛竹笋为原料,采用水提取、乙醇热回流提取和超声波提取3种提取方法,通过单因素和正交设计试验确定了毛竹笋总黄酮提取的最佳条件。结果表明,水提取工艺最佳条件为固液比1∶30(g∶mL,下同),温度60℃,提取时间1.5 h,pH9;总黄酮得率为0.706%,影响得率的因素为固液比>提取温度>提取时间>溶液pH值。乙醇热回流提取最佳条件为固液比1∶40,温度60℃,乙醇体积分数70%,提取时间2.0 h,总黄酮得率为1.063%;影响得率的因素为固液比>提取温度>提取时间>乙醇体积分数。超声波提取工艺最佳条件为提取时间30 min,固液比1∶40,乙醇体积分数70%,提取温度50℃;总黄酮得率为0.797%;影响得率的因素为固液比>提取温度>提取时间>乙醇体积分数。     

二次回归正交设计优化紫茎泽兰中黄酮的提取工艺

[目的]研究从紫茎泽兰中提取黄酮的最佳工艺条件。[方法]以黄酮的得率为目标，使用单因素试验方法考察乙醇浓度、提取温度、固液比以及提取时间对黄酮得率的影响，使用回归正交组合设计优化提取工艺。[结果]最优的黄酮工艺条件为：固液比为1：30，提取时间为2．5h，乙醇浓度为53％，提取温度为70℃。[结论]使用回归正交组合设计能合理地优化紫茎泽兰中黄酮的提取工艺，为紫茎泽兰的综合利用提供参考。     

微波法提取脐橙皮黄酮工艺研究

[目的]探讨提取条件对脐橙皮中黄酮提取率的影响,确定提取最佳工艺条件。[方法]以脐橙皮为原料,采用微波提取,通过单因素试验和L9（34）正交试验,探索微波功率、乙醇浓度、料液比、处理时间4个因素对黄酮提取的影响,确定黄酮提取最佳工艺。[结果]微波提取脐橙皮中黄酮的最佳工艺条件：处理时间为120s,料液比为1：15,乙醇浓度为60%,微波功率为180W。4因素对黄酮提取率的影响依次为料液比〉微波功率〉乙醇浓度〉提取时间,其中料液比和微波功率的影响比较大。在最佳条件下,微波提取脐橙皮黄酮的提取率为5.27%。[结论]用微波法提取脐橙皮黄酮提高了提取的速度和得率,具有不产生噪音、能耗低、效率高、不破坏有效成分等特点。     

苹果渣总黄酮提取方法的探讨

以苹果渣总黄酮得率为考察指标,对苹果渣总黄酮提取方法及其影响因素作了探讨,获得微波法和水浴法提取黄酮的最佳工艺参数,通过两者比较证明微波法提取为较理想的黄酮提取方法。苹果渣总黄酮水浴提取法的最佳提取条件为水浴温度70℃、乙醇浓度65%、提取时间2.0 h、固液比1∶25,该条件下测得总黄酮的得率为6.07%;微波法最佳提取条件为微波低火档位、乙醇浓度55%、提取时间210 s、固液比1∶25,该条件下测得总黄酮的得率为5.98%。     

正交法优化黄精地上茎叶中有效成分的提取工艺

以黄精(Polygonatum sibiricum)地上部茎叶为试材,采用单因素试验研究了料液比、提取温度、提取时间和乙醇体积分数对提取黄酮、多酚和多糖得率的影响。通过正交试验优化黄酮、多酚和多糖的提取工艺。结果表明,提取黄酮最佳条件为提取温度70℃,料液比1∶80,提取时间2.5 h,乙醇体积分数为90%,黄酮平均得率为4.01%;提取多酚最佳条件为料液比1∶40,提取温度80℃,提取时间1.0 h,乙醇体积分数为60%,多酚平均得率为0.62%;提取多糖的最佳条件为提取温度80℃,料液比1∶20,提取时间2.0 h,多糖平均得率为18.61%。验证试验表明,这3种优化工艺稳定可行。     

Web2.0,以个人为中心的互联网时代的到来

本文介绍了Web2．0的知识和背景，对Web2．0出现的基础以及典型技术和应用作了阐述，同时对其作出了前景展望。     

市级综合气象信息分析与管理系统的设计与实现

以抚顺地区3个国家基本站50余年气象资料为依托，采用Microsoft Excel工作表实现由气候和农业气候2部分构成的气象与农业综合信息处理系统的基本思路、方法、内容、用途和使用情况。为了实现气候分析及应用的科学化、客观化、系统化、规范化、程序化及连续化的业务目标，按业务流程设计与实现的，包括资料处理、气候趋势模拟、气候预测、气候鉴定、季节性信息化处理、农作物产量预报、气候生产潜力分析等一系列内容在内的系统建设。关键是解决了大量的计算问题，建立了区域性通用模式。     

Multi-variable grey model (MGM (1,n,q)) based on genetic algorithm and its application in urban water consumption

Urban water consumption has some characteristics of grey because it is influenced by economy, population, standard of living and so on. The multi-variable grey model （MGM（1,n））, as the expansion and complement of GM（1,1） model, reveals the relationship between restriction and stimulation among variables, and the genetic algorithm has the whole optimal and parallel characteristics. In this paper, the parameter q of MGM（1,n） model was optimized, and a multi-variable grey model （MGM（1 ,n,q）） was built by using the genetic algorithm. The model was validated by examining the urban water consumption from 1990 to 2003 in Dalian City. The result indicated that the multi-variable grey model （MGM（1,n,q）） based on genetic algorithm was better than MGM（1,n） model, and the MGM（1,n） model was better than MGM（1,1） model.     

Molecular detection of virulence genes in Campylobacter species isolated from livestock production systems in South Africa

Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.     

不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响

 【目的】通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异，探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量。【方法】以木薯品种南美119为材料，采用“3414”方案，在粤北翁源进行大田试验。试验共设14个处理。【结果】施肥处理的氮素主要分配到地上部，不施肥处理的氮素则主要分配到根部；不同施肥处理的磷素均主要分配到地上部；不施肥处理和不施钾处理的钾素主要分配到根部，不施氮处理的钾素在根、冠间分配较均衡。在木薯不同生长阶段，植株氮磷钾含量均呈下降趋势，但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理。处理N2P2K2的氮、磷、钾含量和积累量在各生育期均为最大，不施肥处理（N0P0K0）的氮、磷、钾含量和积累量在各生育期均为最小（P＜0.05）。产量最高的是N2P3K2处理，为22 694.06 kg·hm-2，其次是N2P2K2处理，为21 417.87 kg·hm-2。【结论】木薯产量、氮磷钾养分积累及其在根冠间的分配，对施肥水平高度敏感, 适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量，又可以提高产量。在粤北坡岗地木薯生产中，氮素最重要，在氮素得到满足的条件下，磷素较钾素更重要。在本试验条件下，氮磷钾养分最佳用量为358.80 kgN·hm-2、89.10 kg P2O5·hm-2和187.50 kg K2O·hm-2。     

红苕饲粮中添加铜和/或喹乙醇对猪生产性能及某些血液生化指标的影响

选体重约38公斤的长白(♂)×成华(♀)杂交猪20头,随机分为四组,饲予四种不同的饲粮,研究饲粮中添加铜和/或喹乙醇对猪生产性能和某些血液生化指标的影响。结果表明:基础组、加铜组、加喹乙醇组和两者同时加组全期日增重分别为674、761、796、678克,日采食量分别为2.50、2.65、2.74、2.40公斤,饲料利用率分别为3.73、3.49,3.44、3.54,添加铜和/或喹乙醇对试验第65天血清铜兰蛋白、尿素氨及屠宰率、背膘厚和眼肌面积无显著影响(p>0.05);添加铜使65天血清碱性碱酸酶活性极显著增高(p<0.01),添加喹乙醇有使之升高的趋势,两者同时添加时,碱性酸磷酶活性降低。     

Current progress on genetic interactions of rice with rice blast and sheath blight fungi

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.     

Virus Location and Lymphocyte Apoptosis in Lymph Nodes of Piglets Infected with PCV-2

The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ （PCV-2）. Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups： control group （n = 3）, piglets inoculated with PCV-2 alone （PCV-2, n = 3）, and PCV-2 inoculated and KLH immunostimulated group （PCV-2 ＋ KLH, n = 3）. Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling （TUNEL） and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 ＋ KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 ＋ KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 ＋ KLH piglets were significantly higher than those for the control group （P〈0.05 and P〈0.01）. The proliferation index （PI） was 0.17_＋0.01, 0.12_＋0.01 and 0.12_＋0.04 in the control, PCV-2, and PCV-2 ＋ KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o     

锌对镉·汞复合污染下豌豆幼苗生长的影响

以豌豆为试验材料,采用水培方法研究了锌对镉、汞复合污染下的豌豆种子萌发与生长的影响。结果显示,锌浓度≤100.0 mg/L时促进豌豆种子的萌发,锌浓度为200.0和300.0 mg/L时抑制豌豆种子的萌发。当镉、汞的浓度为3.0 mg/L时,100.0 mg/L锌的解毒效应最明显,表现为能够促进镉、汞胁迫下豌豆种子萌发和幼苗生长,降低豌豆幼苗根尖细胞畸变率,提高豌豆幼苗的叶绿素含量及过氧化物酶活性;但当锌浓度≥200.0 mg/L时,与镉、汞协同迫害豌豆幼苗的生长。     

仙人掌超氧化物歧化酶提取与纯化研究

以仙人掌为试验材料,采用硫酸铵分级沉淀法得到超氧化物歧化酶（Superoxide Dismutase,SOD）粗酶液。然后用Sephadex（葡聚糖凝胶）G-75层析柱层析对粗酶液进行进一步纯化,最后用邻苯三酚法测定酶活力,并对酶活力主要影响因素（包括pH值、温度、抑制剂）进行了研究。结果显示仙人掌SOD酶比活力为751.56U.mg-1。pH值为7.5~8.5时酶活力最大,稳定性也好。温度维持在25~30℃时酶活力最高。由于过氧化氢和氰化钾均能使仙人掌SOD的酶活力显著下降,因而可以初步判断从仙人掌中提取到的SOD是Cu.Zn-SOD。