MiSeq测序研究散装酱卤鸭肉贮藏期间微生物群落多样

为研究散装酱卤鸭肉贮藏过程中微生物变化规律,揭示其腐败本质,以期为确定其特定腐败菌（Specific Spoilage Organisms,SSO）提供依据,本文采用MiSeq测序分析其在4 ℃和25 ℃贮藏过程中微生物群落多样性。结果表明,样品在4 ℃和25 ℃贮藏过程中细菌和真菌物种多样性在总体上均呈现下降趋势。样品贮藏初期优势细菌是Weissella sp.、Staphylococcus sp.、和未分类的肠杆菌科,优势真菌是Debaryomyces sp. IZ_1257和Lodderomyces elongisporus。4 ℃贮藏中后期,肺炎嗜冷杆菌（Psychrobacter pulmonis）和Staphylococcus sp.为主要优势细菌;而25 ℃贮藏中后期的优势细菌则为Weissella sp.、Staphylococcus sp.、溶酪大球菌（Macrococcus caseolyticus）和未分类的肠杆菌科。4 ℃、25 ℃贮藏中后期样品中最主要优势真菌均为Debaryomyces sp. IZ_1257。相比较于传统方法,MiSeq测序提供的微生物多样信息更接近于样品微生态,更能够全面解析各环境样品微生物多样性。     

双歧杆菌活菌颗粒制剂对小鼠肠道菌群的调节作用

双歧杆菌是得到广泛公认的益生菌。它除了能合成多种维生素外,还能在人体肠道内形成一个生物学屏障,有效地抑制、阻止致病菌和条件致病菌在肠道中入侵和定植,从而调整与改善人体肠道中的微生态环境,达到调理肠胃,增强免疫功能,抑制肿瘤和延缓衰老的效果。由于益生菌的特殊生理作用,使国内外医学界纷纷尝试应用益生菌制作保健品。目前,国内对双歧杆菌的基础性研究和活菌制剂的开发都十分活跃,其生物制剂已应用于临床治疗。含双歧杆菌活菌的保健品也深受群众的喜爱。本文观察了保健食品“某双歧杆菌活菌颗粒剂”对小鼠胃肠道菌的调节作用,报告…     

豌豆超微粉碎膳食纤维对糖尿病小鼠肠道菌群及其代谢产物的影响

目的：研究豌豆超微粉碎膳食纤维（ultrafine ground pea dietary fiber,UGPDF）对糖尿病小鼠肠道菌群及其代谢产物的影响,从而揭示其降血糖的作用机制。方法：通过腹腔注射链脲佐菌素建立糖尿病小鼠模型,用二甲双胍和高剂量（0.9 g/（mL·d））、低剂量（0.45 g/（mL·d））UGPDF分别灌胃干预4 周,测定小鼠血糖浓度、观察肝脏细胞形态变化,Western blot检测小鼠肝脏中磷脂酰肌醇-3-激酶（phosphatidylinositol-3-kinase,PI3K）/蛋白激酶B（protein kinase B,AKT）/类胰岛素生长因子（insulin-like growth factors,IGF）蛋白表达水平,高通量测序分析各组小鼠粪便中的肠道菌群组成。结果：UGPDF能够调节糖尿病小鼠的肠道菌群丰度及多样性,高剂量UGPDF组操作分类单元（operational taxonomic units,OTU）数达300±36,其Shannon、Simpson指数与糖尿病小鼠存在显著差异（P＜0.05）。在肠道菌群组成中,与模型组相比,UGPDF干预后,Lactobacillus、Lachnospiraceae有益菌相对丰度显著上升（P＜0.05）,Helicobacter、Klebsiella、Clostridium致病菌相对丰度显著下降（P＜0.05）。从代谢产物来看,与模型组相比,经过UGPDF干预后,小鼠粪便内的6 种短链脂肪酸含量总体显著升高（P＜0.05）,其中以高剂量组效果最为显著,乙酸、丙酸、丁酸含量分别提高了63.7%、75.9%和96.0%,且接近正常对照组。同时,肝脏组织切片及Western blot检测结果表明UGPDF可调节糖尿病小鼠肝脏PI3K/AKT/IGF信号通路,修复肝细胞损伤,提高胰岛素敏感性。本实验可为豌豆膳食纤维的高值化利用拓宽思路,并补充完善其降血糖理论。     

热收缩机的热动态平衡及合理化设计

针对现有热收缩炉存在的能耗高、态平衡速度慢的缺点，对系统进行了全面的合理化改造，特别是对热循环风和温控点的优化设计改造过程充分体现机电一体化思路对整个进程的影响。     

Cytoprotective effects of anthocyanins and other phenolic fractions of Boysenberry and blackcurrant on dopamine and amyloid β‐induced oxidative stress in transfected COS‐7 cells

There is growing interest both from consumers and researchers in the role that berries play in human health. In the experiments reported here, we assessed the ability of anthocyanins and phenolic fractions of Boysenberry and blackcurrant to ameliorate the deleterious effect of the amyloid β_25–35 (100 µmol L^?1, 24 h) and dopamine (1 mmol L^?1, 4 h) on calcium buffering (recovery) of M1 muscarinic receptor‐transfected COS‐7 cells. Cell viability was also studied. Our results demonstrate that extracts of Boysenberry and blackcurrant showed significant protective effect and restored the calcium buffering ability of cells that had been subjected to oxidative stress induced by dopamine and the amyloid β_25–35. Blackcurrant polyphenolics showed slightly higher protective effect against dopamine, whereas Boysenberry polyphenolics had a higher effect against the amyloid β_25–35. In viability studies, all extracts showed significant protective effects against dopamine and amyloid β_25–35‐induced cytotoxicity. Our results provide further evidence for the protective effects of berries against the neurotoxic effect of dopamine and amyloid β_25–35 in brain cells. Copyright © 2007 Society of Chemical Industry     

Effect of usage Urtica dioica L. on microbiological properties of sucuk, a Turkish dry-fermented sausage

The effect of dried-ground Urtica dioica L. on microbiological characteristics of Turkish dry-fermented sausage (sucuk) were investigated. Dried-ground Urtica dioica L. was added to sucuk batters by the rate of 0%, 1%, 3% and 5%, and microbiological analysis were made on the 0, 3, 7, 10 and 14 days of ripening period.

According to the results, both the level of Urtica dioica L. and ripening time had a significant effects on the total aerobic mesophylic bacteria, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae counts (p<0.01). It was determined that the interactions ripening time × the levels of Urtica dioica L. had a significant effects on the counts of total aerobic mesophylic bacteria, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae (p<0.01). Enterobacteriaceae count were also found to be under the detectable level (<100 cfu/g) in sucuks (in day 14 of ripening) containing 3% and 5% Urtica dioica L.     

霉变粉皮的微生物区系分析及防霉措施

从霉变粉皮的微生物区系分析阐述了防霉措施，抑制芽孢杆菌的最经济方法是控制粉皮的含水量，其次是添加防腐剂。     

Seat-belt legislation and risk homeostasis: Further analysis of the British data

It has been suggested that seat-belt legislation may result in drivers' feeling overprotected and their consequent riskier driving may lead to more injuries to other road users (the risk homeostasis or compensation theory). We have examined data in Britain before and after legislation made seat-belt use compulsory for front-seat occupants of specified vehicles. The relative numbers of injuries to cyclists and pedestrians in collisions with vehicles requiring and not requiring seat-belt use were compared, using a loglinear analysis taking into account possible confounding variables. It was not possible directly to incorporate vehicle distance travelled for the two categories of vehicle. However, a simple adjustment for differential vehicle use accounted for most of an apparent effect. The revised odds ratio (for mandated seat-belt use vehicles versus nonmandated, post- versus prelegislation) was 1.04 for cyclists and 1.06 for pedestrians, showing minimal, if any, evidence for the theory.     

Microscopic images of intraspheroidal pH by 1H magnetic resonance chemical shift imaging of pH sensitive indicators

Objective We investigate microscopic pH heterogeneity within tumor spheroids using a novel ¹H NMR methodology that provides high resolution measurements of intraspheroidal pH. Material and Methods: High resolution microscopic images of intraspheroidal pH were obtained by ¹H NMR using chemical shift selective excitation of the H2 resonance of imidazole added to the incubation medium. Imidazole accumulated in the intraspheroidal space in a pH dependent manner. Maps of intraspheroidal pH could be obtained by transforming pixel by pixel (32 × 32$) the regional variation of imidazole H2 intensity into a relative pH scale. Results: Our analysis revealed drastic intraspheroidal pH alterations depending on the size of the spheroid, ca. 0.6 pH units more acidic in the necrotic core than in the periphery, for spheroids of 600 μm diameter. The presence of concentric regions having similar intraspheroidal pH was consistently observed. The thickness of these regions decreased from pH 7.2 to pH 6.8 and increased below the latter pH value. Conclusion: Our observations are compatible with the general model of spheroid growth where the more external layers of cells are in active growth and depict more alkaline pH values while the inner layers remain quiescent or evolve to a necrotic core, depicting more acidic pH values.