响应面优化香草醛-冰醋酸-高氯酸法测定金花茶叶中总皂甙含量

在单因素试验的基础,采用响应面试验,优化了分光光度法测定金花茶总皂甙的显色反应条件。得到的最佳反应条件为院5%香草醛-冰醋酸溶液0.35mL,高氯酸1.0 mL,反应温度80益,反应时间25 min,测定波长540nm。在此条件下,人参皂甙Rg1在0~114.2μg范围内与吸光度呈良好的线性关系,r=0.9991。该方法的相对标准偏差为1.36%,稳定性相对标准偏差为2.08%,平均回收率为98.22%。     

分光光度法测定竹节参中齐墩果酸皂甙含量

[目的]建立测定竹节参中齐墩果酸皂甙含量的方法。[方法]采用分光光度法,以香草醛-高氯酸显色,在波长545nm处测定吸光度。[结果]齐墩果酸线形关系良好,线性范围为0.036～0.120mg/m(lr=0.9976),平均回收率为98.81%,RSD=1.32%(n=5)。[结论]所用方法结果准确,重复性好,专属性强,可用于竹节参中齐墩果酸皂甙含量的测定。     

齐墩果酸分光光度法测定大豆异黄酮粉中总皂苷含量

以大豆皂苷类似物齐墩果酸为标准品,经香草醛-高氯酸显色,应用可见分光光度法在560 nm处分别测定了20%、30%和40%大豆异黄酮粉中总皂苷的含量。测定结果表明,大豆总皂苷的对应含量分别为36.0%、26.3%、16.1%,该方法的线性范围为1～20μg.mL-1,相对标准偏差(RSD)为3.1%,平均加样回收率为101.5%,相关系数R2=0.9996。     

分光光度法测定藜麦中总皂苷的含量

[目的]建立一种测定藜麦中总皂苷的分光光度法,研究藜麦中总皂苷的含量。[方法]采用超声波提取、香草醛-高氯酸分光光度法,以藜麦皂苷A为对照品,检测波长482 nm,样品提取采用60%乙醇溶液,料液比1∶30(g∶mL),提取时间30 min,提取2次,回收乙醇后用水饱和的正丁醇萃取3次。[结果]藜麦中总皂苷浓度在0.021 12~0.063 36 mg/mL范围内具有良好的线性关系,线性方程为A=12.169C-0.071 4,相关系数0.999 9。[结论]建立了超声波提取-分光光度法测定藜麦中总皂苷含量的新方法,该方法简便、准确,可用于藜麦加工工艺的评价。     

紫外分光光度法测定大花暗罗叶和枝中总三萜的含量

采用紫外分光光度法测定了大花暗罗(Polyalthia rumphii叶和枝中总三萜的含量.以乌苏酸为对照品,以5％香草醛-冰醋酸和高氯酸系统为显色剂,在546 nm波长处测定样品的吸光度.乌苏酸对照品在0.2～1.6μg/mL范围内呈良好线性关系,回归方程为A=0.160 3C+0.031 2,R2=0.999 4.大花暗罗枝和叶中总三萜的含量分别为0.446％和0.956％.该方法操作简便、结果稳定、重复性好、易于推广.     

紫外分光光度法测定海南木莲叶·枝中总三萜酸的含量

[目的]测定海南木莲叶和枝中总三萜酸的含量。[方法]以熊果酸为对照品,以质量分数5%香草醛-冰醋酸和高氯酸系统为显色剂,采用紫外分光光度法在546nm波长处测定样品的吸光度。[结果]熊果酸对照品在0.2～1.6μg/ml时呈良好线性关系,回归方程为A=0.1548C＋0.0286,r=0.9993。海南木莲叶和枝中总三萜酸的含量分别为1.95%和0.47%。[结论]该方法操作简便,结果稳定,重复性好,易于推广。     

藜麦皂甙的测定研究

用高氯酸比色法对藜麦中皂甙的测定进行了研究,并且测定了水洗后藜麦皂甙的含量变化。结果表明,用香草醛-高氯酸比色法测定藜麦中的皂甙含量是一种方便快捷、结果稳定的方法。测定藜麦皂甙选用齐墩果酸为标准品,波长为560 nm,标准曲线方程为y=0.196 6x-0.013 7,并且R2显示在此范围内有良好的线性关系。提取样品皂甙的条件为:提取液乙醇的体积分数为70%,料液比为1∶30,提取温度为50℃。结果测定的藜麦皂甙含量为10.709 mg/g,水洗之后藜麦中皂甙含量有所减少,清洗的次数越多,藜麦中皂甙的含量越少,清洗3次后藜麦中总皂甙含量由原来的10.709 mg/g降低为6.077 mg/g,减少了43.25%。并且水洗去除藜麦种皮中的皂甙占总去除皂甙的87%。     

紫外分光光度法测定八角枫中水杨苷的含量

为建立紫外分光光度法测定八角枫中水杨苷的含量,以水为溶剂,回流提取八角枫中水杨苷,采用香草醛-高氯酸法显色,紫外分光光度法扫描,确定最大吸收波长,通过精密度试验,稳定性试验,加样回收试验建立水杨苷含量的测定方法。水杨苷的紫外扫描的结果表明:水杨苷的最大吸收波长为281nm,水杨苷标准液浓度在34.40~172.10μg·mL~(-1)时浓度与吸光度呈现良好的线性关系,线性回归方程为Y=0.0063 X-0.0107,r=0.999 3,加样回收率为100.29%。该方法操作简便、准确、快速,可用于八角枫中水杨苷的定量检测。     

测定酸枣仁提取物中酸枣仁皂苷A和B的方法

建立和优化了测定酸枣仁提取物中酸枣仁皂苷A和B的方法。在紫外分光光度法中，用香草醛－高氯酸显色，检测波长415nm；HPLC-ELSD法的检测条件为：Inertsil ODS-3C18柱，甲醇＋水（70＋30）为流动相，柱温45℃，流速为1．0mL／min，ELSD气化室温度110℃，气体流速3．0L／min。实验结果：耶LC-ELSD法检测酸枣仁皂苷A在0．0785-0．2256mg／mL范围内线性关系良好（r=0．9997），平均回收率98．28％；酸枣仁皂苷B在0．0643-0．2392mg／mL范围内线性关系良好（r=0．9995），平均回收率98．86％。紫外分光光度法检测酸枣仁皂苷A在0．0475-0．5832mg／mL范围内线形关系良好（r=0．9981）。结论：I-IPLC-ELSD法与紫外分光光度法相比更简便、快速，准确性高、重现性好，更适合用于酸枣仁提取物中酸枣仁皂苷的定量分析。     

黔产竹节参总皂苷含量测定条件的优化

为确定香草醛-硫酸-甲醇分光光度法测定黔产竹节参总皂苷含量的优化条件,利用酸性条件下,香草醛与人参皂苷生成有色化合物,进行比色测定,通过正交试验对影响比色反应的因素进行优化。结果显示:有色化合物在496nm有最大吸收,优化条件下制备的总皂苷回归方程为:A=0.0012+0.004716C,相关系数r=0.9991,线性范围为0.007～0.035mg/mL,平均加标回收率为:99.15%,RSD=0.17%(n=5)。表明:该条件下测定黔产竹节参总皂苷含量,结果准确、可靠,重复性好。     

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。     

盐胁迫对葡萄苗期多胺和激素代谢的影响

【目的】 研究盐胁迫条件下,葡萄叶片中多胺含量、多胺氧化酶、多胺合成酶活性以及激素的动态变化,研究不同盐胁迫强度对多胺类物质及激素代谢的影响。【方法】 采用盆栽基质培养模拟盐胁迫环境,设置4个NaCl处理梯度:0 (CK)、1、2和3 g/kg。多胺和激素含量的测定采用高效液相色谱法,多胺合成及分解酶活性的测定采用紫外分光光度计比色法。【结果】 盐胁迫处理后,葡萄叶片中多胺含量和脱落酸含量较对照而言显著增加,玉米素含量显著降低,随胁迫时间的延长,Put、Spm、Spd、ABA以及PAO、DAO、ADC、ODC、SAMDC活性均呈先上升后下降趋势,在10 d及10 d后达到峰值。ZT呈逐渐下降的趋势,并随胁迫强度增大而减小;进行显著性分析后,叶片中多胺含量与Put、Spm、Spd含量呈极显著正相关,DAO、ADC、ODC活性与Put含量呈显著正相关,PAO与SAMDC活性与Spm和Spd含量也呈极显著正相关。【结论】 3种多胺经酶的合成代谢后和激素共同缓解葡萄苗所遭受到的盐胁迫,期间主要发生作用的是多胺合成酶,盐胁迫下多胺与激素含量之间的变化关系也十分密切。     

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.     

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。     

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。     

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     

内脐蠕孢属、平脐蠕孢属和凸脐蠕孢属的研究

本文报道了平脐蠕孢属(Bipolaris)一个新种,一个新组合,5个新记录以及凸脐蠕孢属(Exserohilum)一个新记录。讨论了内脐蠕孢属(Drechslera)、平脐蠕孢属、凸脐蠕孢属与长蠕孢属(Helminthosporium)的关系,并就我国已报道的长蠕孢属真菌按Alcorn等~([1,3,4,5,24])人的意见,逐个进行了订正。