不同水解方法对藜麦皂苷抑菌活性及酪氨酸酶抑制作用的影响

本实验以藜麦麸皮为材料,通过双相酸水解法、直接酸解法、酶解法三种方法去处理藜麦麸皮,并利用正丁醇萃取获得藜麦低级性皂苷。经过最低抑菌浓度（minimum inhibitory concentration,MIC）、最低杀菌浓度（minimum bactericidal concentration,MBC）及纸片法测定抑菌活性;并用酪氨酸酶抑制实验推测其抑制黑色素作用。最后用液相色谱质谱/质谱联用法（liquid chromatography electrospray ionisation tandem mass spectrometry,LC-MS/MS）和高效液相色谱法（high performance liquid chromatography,HPLC）来对抑菌和抑制酪氨酸酶活性效果最好的化合物进行定性定量分析。结果表明：经过双相酸水解转化的化合物活性最好,对金黄色葡萄球菌和沙氏肠炎杆菌的MIC=0.60 mg/mL,MBC=1.20 mg/mL,对表皮葡萄球菌的MIC=0.30 mg/mL,MBC=1.20 mg/mL;对铜绿假单胞菌有一定的抑制作用。0.5 mg/mL的转化物对酪氨酸酶的抑制率达到68.09%。根据LC-MS/MS及HPLC可知,经正丁醇萃取的水解后的化合物为皂苷。经过两相酸解后,部分皂苷发生了水解反应,造成了化合物极性的降低。利用双相酸水解法从藜麦麸皮中萃取藜麦皂苷元提高了化合物的活性,增强了皂苷的抑菌和酪氨酸酶抑制作用,并且提取率明显高于直接酸解法和酶解法。     

汉族和藏族婴儿肠道微生物群落结构和多样性分析

为了解民族因素对婴儿的影响,对中国汉族和藏族母乳喂养的健康婴儿粪便微生物菌群进行研究。通过16S rRNA高通量测序技术,发现两组粪便微生物的组成存在差异。在门水平上,汉族婴儿的放线菌门相对丰度较高,而藏族则以厚壁菌门为主,且两组间的厚壁菌门差异显著（P＜0.05）。基于UniFrac的非加权和加权的主坐标分析表明汉族和藏族婴儿肠道微生物群结构有显著性差异。此外,偏最小二乘判别分析显示两组间微生物明显分离。研究表明,肠道微生物群可以在不同民族的婴儿之间进行区别,从而扩展人类及其共生肠道微生物群共同进化的认识。     

基于近红外光谱技术检测红曲米中的红曲色素

采用近红外光谱技术结合化学计量学方法构建红曲米中红曲橙色素、红曲红色素、红曲黄色素的预测模型。分别采用多元线性回归(SMLR)、偏最小二乘回归(PLS)、主成分回归(PCR)构建所有色素组分的数学模型,以相关系数(R)、校正均方根误差(RMSEC)、预测均方根误差(RMSEP)、预测相对分析偏差(RPD)值来评价模型的综合性能。结果显示,MSC、SNV方法能够消除红曲米粉颗粒不均对光谱的散射影响;导数处理消除了基线漂移;对于红曲橙色素、红曲黄色素、红曲红色素三种模型均具有良好的稳定性;利用三种模型对未知红曲样品预测时,预测结果具有较高的线性,预测性能较好(RPD=2.86~5.39),可用于准确定量预测。结果表明近红外光谱技术可用于红曲色素的快速无损测定,为红曲米质量的智能化控制提供了新的途径。     

氧化羊骨油脂肪酸组成及挥发性风味物质分析

采用气相色谱与气相色谱-质谱联用技术,分析氧化及未氧化羊骨油中脂肪酸组成与挥发性风味物质成分。通过"相对气味活度值(ROAV)"评价各挥发性风味物质对羊骨油总体风味的贡献,并结合聚类分析方法,确定氧化后羊骨油的关键挥发性风味物质。结果表明:羊骨油中检测出7种脂肪酸,其中包括3种饱和脂肪酸和4种不饱和脂肪酸,氧化使得羊骨油中亚油酸含量显著降低(P0.05);羊骨油中反-2-烯醛和反,反-2,4-二烯醛等醛类化合物为主要挥发性物质,氧化后羊骨油挥发性风味物质种类增加了22种,总峰面积是未氧化羊骨油风味物质总面积的4倍以上;亚油酸的氧化产物反-2-壬烯醛是羊骨油氧化后生成的最关键挥发性风味物质。总之,氧化羊骨油可以产生大量挥发性风味物质,并对脂肪香气起到强化作用。     

Exclusion of NUMB Exon12 Controls Cancer Cell Migration through Regulation of Notch1-SMAD3 Crosstalk

NUMB is an endocytic adaptor protein that contains four isoforms (p65, p66, p71 and p72) due to alternative splicing regulation. Here, we show that NUMB exon12 (E12)-skipping isoforms p65/p66 promote epithelial to mesenchymal transition (EMT) and cancer cell migration in vitro, and facilitate cancer metastasis in mice, whereas E12-included p71/p72 isoforms attenuate these effects. Mechanistically, p65/p66 isoforms significantly increase the sorting of Notch1 through early endosomes (EEs) for enhanced Notch1 activity. In contrast, p71/p72 isoforms act as negative regulators of Notch1 by ubiquitylating the Notch1 intracellular domain (N1ICD) and promoting its degradation. Moreover, we observed that the interaction between N1ICD and SMAD3 is important for their own stabilization, and for NUMB-mediated EMT response and cell migration. Either N1ICD or SMAD3 overexpression could significantly recuse the migration reduction seen in the p65/p66 knockdown, and Notch1 or SMAD3 knockdown rescued the migration advantage seen in the overexpression of p66. Taken all together, our study provides mechanistic insights into the opposite regulation of Notch1-SMAD3 crosstalk by NUMB isoforms and identifies them as critical regulators of EMT and cancer cell migration.     

Increased productivity

Higher productivity is often demanded of project managers. This paper looks at typical demands made for increasing productivity and some possible responses. Eliminating inefficiency is considered. Distinction is drawn between project-oriented approaches and those with a more wide-ranging and far-reaching effect.     

Risk assessment for listeriosis in consumers of Parma and San Daniele hams

Following the detection of Listeria monocytogenes in samples of dry cured ham imported in the USA from Italy, the Italian Ministry of Health planned a risk assessment for listeriosis in ham consumers. The risk assessment was performed according to international guidelines set by FAO and WHO. Expected incidence of illness was 4.7 × 10⁻¹⁰ cases per serving in the case of normal adult population, 6.1 × 10⁻⁷ in the case of organ transplanted patients, the most susceptible risk sub-population. Due to the low value of water activity even in the deeper parts of the ham, bacterial growth had a very slight effect on the probability of illness.     

Increasing the filtration rate of phospho-gypsum using surfactant

Phospho-gypsum is a by-product of processing phosphate rock for phosphoric acid production by acidulation with sulfuric acid. The size distribution of phosphor-gypsum is a major factor for the economics of the process as it greatly affects the filterability of the acid. Surface active agents proved to be very effective additive for growth of gypsum crystals. Two phosphate concentrates, one from Egypt (New Valley) and the other from USA (South Florida) were tested for phosphoric acid production with modification of gypsum crystals using non-ionic surfactant (CMR-100) containing a mixture of C₆–C₂₂ sorbitan esters. The studies were carried out using a semi-continuous laboratory-scale unit simulating the dihydrate process conditions.The mean diameter of the phospho-gypsum crystals increases in the presence of surfactant for both phosphate concentrates. The surfactant leads to decreasing the viscosity and modification of gypsum crystals through decreasing the fine size fractions and attainment of large and uniform crystal shape. The mean diameter of New Valley phosphor-gypsum increases from about 30.0 μm to 36.6 μm while the mean diameter of South Florida phospho-gypsum increases from about 30.3 μm to about 38.4 μm. On the other hand, the average surface area of both New Valley and South Florida phosphor-gypsum were decreased from 4461 and 8069 cm²/g without surfactant to 3284 and 3995 cm²/g with surfactant, respectively. In addition, the surfactant leads to an increase in P₂O₅ recovery of 1–2%, which consequently improves plant productivity.     

Effect of pan-frying in different culinary fats on the fatty acid profile of pork

This study was set up to determine how pan-frying either without culinary fat or with different culinary fats (polyunsaturated fatty acids (PUFA)-enriched culinary fat, olive oil and margarine) affects the fatty acid (FA) composition of pork. The meat samples (longissimus thoracis (LT)) originated from pigs fed different dietary fat sources (animal fat, soybean oil or linseed oil) and thus had different FA compositions before frying. Pan-frying resulted in considerable increases in the meat total-FA content, although this was not always significant and highly variable, despite standardisation of the frying process. The FA composition of the pan-fried meat tended to become similar to that of the culinary fat used, and the extent of changes in the content of a particular FA was relative to the FA gradient from the culinary fat to the meat. However, this was also dependent on the culinary fat used, since frying in olive oil appeared to affect the FA composition of the meat more than did frying in the other culinary fats. Differences in FA composition of meat resulting from different animal feeding treatments remained unchanged after pan-frying without fat, they became smaller after frying in margarine and PUFA-enriched culinary fat, whereas frying in olive oil largely masked the initial FA profile differences. Long chain PUFA (LCPUFA) in the meat were not significantly lost by the frying process, but their proportion was influenced by the uptake of the culinary fat.     

Dietary arsenic intakes in the United States: FDA Total Diet Study, September 1991-December 1996

The FDA has conducted the Total Dietary Study (TDS), a yearly market basket programme, since 1961. It is designed to monitor the levels of toxic chemical contaminants (pesticide residues, industrial and elemental contaminants) and essential nutrients in the US food supply. It also provides information on trends in dietary concentrations and exposures for the general population. Foods are collected from retail stores once a year from each of four geographic areas of the US and are analysed either after preparation/cooking or as ready-to-eat. The latest TDS (1991-1997) data show that arsenic (inorganic and organic, ≥ 0.03ppm) was found in 63 (24%) of the 261-264 foods/mixed dishes analysed. The highest concentration was found in seafood, followed by rice/rice cereal, mushrooms, and poultry. Based on the United States Department of Agriculture's 1987-1988 Nationwide Food Consumption Survey, the estimated daily total arsenic average intakes, in mu g/day, are: 2 for infants, 23 for toddlers, 20 for 6-year-old children, 13 for 10-yearold children, 15 for 14-16-year-old boys, 21 for 14-16-year-old girls, 57 for 25-30-year-old men, 28 for 25-30-year-old women, 47 for 40-45-year-old men, 37 for 40-45-year-old women, 92 for 60-65-year-old men, 72 for 60-65-year-old women, 69 for 70-year-old men, and 42 for 70-year-old women. Of the estimated total arsenic intakes for infants, 42% arise from seafood and 31% from rice/rice cereals. Of the estimated total arsenic intakes, seafood contributes 76-90% for children (2-10-year olds), 79-85% for 14-16-year olds, and 89-96% for adults (≥ 25-30-year olds); rice/rice cereals contributes 4-8% for children, 8% for 14-16-year olds, and 1-4% for adults (≥ 25-30-year olds).