2007～2009年济南市部分市售食品中二氧化硫残留状况调查

[目的]了解济南市市售食品中二氧化硫残留状况,为制定相应的监管措施提供依据。[方法]2007年4月至2009年3月,在济南市采集市售6类食品,检测二氧化硫残留量。[结果]检测6类207份食品,168份检出二氧化硫,检出率为81.16%;超标的30份,超标率为14.49%。[结论]济南市市售食品中二氧化硫检出率与超标率均较高。     

Redox therapeutics in hepatic ischemia reperfusion injury简

Ischemia-reperfusion plays a major role in the injury experienced by the liver during transplantation. Much work has been done recently investigating the role of redox species in hepatic ischemia-reperfusion. As animal models are better characterized and developed, and more insights are gained into the pathophysiology of hepatic ischemia reperfusion injury in humans the questions into exactly how oxidants participate in this injury are becoming more refined. These questions include effects of cellular location, timing of injury, and ability of therapeutics to access this site are increasing our appreciation of the complexity of ischemia reperfusion and improving attempts to ameliorate its effects. In this review, we aim to discuss the various methods to alter redox chemistry during ischemia reperfusion injury and future prospects for preventing organ injury during hepatic ischemia reperfusion.     

亚硝酸盐暴露致雄性小鼠生殖毒性的探讨

目的 探讨亚硝酸盐暴露对雄性小鼠生殖毒性的分子机制。 方法 36只2月龄健康雄性小鼠,随机分为对照组(生理盐水）、低剂量组（60 mg/kg）和高剂量组（120 mg/kg）,每组12只进行亚硝酸盐灌胃3个月,观察小鼠的生长状况,HE染色法观察睾丸组织病理变化,免疫荧光和Western blotting方法分析检测睾丸组织细胞增殖与凋亡情况及DNA甲基化、组蛋白去乙酰化相关酶的表达情况。 结果 亚硝酸盐暴露组小鼠较对照组小鼠体重增加缓慢,睾丸指数降低（P<0.01）,形态发生病理性改变;亚硝酸盐暴露组小鼠睾丸组织细胞增殖较对照组明显减少,细胞凋亡较对照组明显增加（P<0.01）;同时DNA甲基化和组蛋白去乙酰化水平高于对照组（P<0.01）,且均具有剂量依赖性。 结论 亚硝酸盐暴露通过抑制雄性小鼠生长发育及睾丸生精细胞增殖,诱导睾丸生精细胞凋亡,造成雄性生殖毒性;DNA甲基化及组蛋白去乙酰化水平升高,提示表观遗传学可能参与了亚硝酸盐暴露对雄性生殖系统的损伤过程及调控机制。     

2012年信阳市熟肉制品中亚硝酸盐监测结果

目的 测定信阳市熟肉制品中亚硝酸盐的含量,了解亚硝酸盐的使用现状.方法 采集信阳市辖区内专营店、超市、集贸市场的熟肉制品,依据食品安全国家标准GB 5009.33-2010《食品中亚硝酸盐与硝酸盐的测定》进行检测,按照《食品添加剂使用标准》(GB 2760-2011)进行卫生学评价.结果 2012年共检测熟肉制品185份,合格144份,合格率77.84％;不同采样地点亚硝酸盐合格率差异无统计学意义(x2=0.784,P＞0.05);不同类别产品中亚硝酸盐合格率差异无统计学意义(x2 =2.764,P＞0.05).结论 信阳市熟肉制品中亚硝酸盐合格率不容乐观,相关部门应加强对亚硝酸盐使用的监管,采取有针对性的控制措施,让消费者能食用到安全卫生的食品,确保公众身体健康.     

Edible bird's nests—How do the red ones get red?

Ethnopharmacological relevance

Red edible bird's nests are regarded as of higher beneficial value for health and hence fetch a higher price than the white ones. Their red colour remains a myth.

Aim of the study

To determine if white edible bird's nests can turn red by vapours generated from sodium nitrite in acidic conditions and by vapours from ‘bird soil’.

Materials and methods

White edible bird's nests were exposed to vapours from sodium nitrite dissolved in 2% HCl or from ‘bird soil’ in hot and humid conditions.

Conclusions

Vapours from sodium nitrite dissolved in 2% HCl or from ‘bird soil’ containing guano droppings from swiftlet houses were able to turn white edible bird's nests red. The reddening agent in ‘bird soil’ was water-soluble and heat-stable. The red colour of edible bird's nests is likely caused by the environmental factors in cave interiors and swiftlet houses.     

Nitrite reduction in acidic solution at a GC/Eastman-AQ-Os(bpy)32+-PVP composite modified electrode

The negatively charged polymer polyester sulfonic acid (Eastman-AQ, abbreviated to AQ), positively charged polymer polyvinyl pyridine (PVP) and mediator Os(bpy)₃²⁺ were used to construct composite modified glassy carbon (GC) electrodes (abbreviated to GC/AQ-Os(bpy)₃²⁺-PVP). The reduction of NO₂^? in acidic solution was taken as a model reaction to explore the properties of the modified electrode. On the steady state polarization curve of NO₂^? reduction there were two well-developed waves with much enhanced plateau current densities and positively shifted half-wave potentials compared with bare GC electrodes. In 0.05 mol/l H₂SO₄ + 5 mmol/l NO₂^? the modified electrode exhibited plateau current densities of 723 and 1153 μA cm^?2 and half-wave potential shifts of 0.29 and 0.56 V for the first and second current wave, respectively, showing promising potential for nitrite detection. The catalytic activity for NO₂^? reduction did not decrease appreciably over 4 months. A number of relevant kinetic and thermodynamic parameters are estimated experimentally. NO₂^? reduction at the composite modified electrodes is suggested to follow the SR mechanism (pure kinetic conditions involving mutual compensation between a catalytic reaction and substrate diffusion in the film in addition to diffusion in the solution phase) according to the Savéant–Andrieux theory.     

Electroreduction of methyl viologen in the presence of nitrite. Its influence on enzymatic electrodes

The electroreduction of methyl viologen (MV) in the presence of nitrite was studied by cyclic voltammetry. A catalytic wave for the reduction of MV²⁺ was observed at ?0.740 V for which an EC catalytic mechanism is proposed. The rate constant for this chemical reaction under pseudo-first-order conditions, evaluated using working curves, was employed in the simulation of the voltammetric response. The second-order rate constant was also evaluated. Influences of the reaction at ?0.800 V on enzymatic electrodes employing nitrate reductase (NR) and MV⁺ as mediator were also analysed by chronoamperometry.     

高脂血症患者红细胞左旋精氨酸转运及一氧化氮变化的研究

目的:观察单纯高脂血症患者红细胞左旋精氨酸(L-Arg)转运及一氧化氮的变化。 方法:高脂血症患者12例(高脂组)和健康者12例(对照组)。两组在年龄、性别上匹配。空腹取血测定血脂水平、血浆亚硝酸盐(NO2-)含量;以3H-L-Arg测定红细胞L-Arg转运。 结果:高脂组血浆中NO2-水平为对照组的4.7倍(P<0.01),高脂组红细胞L-Arg最大转运速率(Vmax)较对照组增加33％(P<0.01),其中y+载体介导Vmax增加47％(P<0.01),而总转运、y+载体介导转运亲和力(Km)无明显变化(P>0.05);y+L载体介导转运与对照组差异无统计学意义(P>0.05)。 结论:高脂血症时红细胞L-Arg/一氧化氮系统发生异常改变。     

一起亚硝酸盐引起食物中毒事件的调查

目的调查了解2004年7月20日卫辉市某化工厂13名工人先后出现恶心、呕吐、口唇紫绀等症状的发病原因。方法通过流行病学调查结合临床表现及实验室检查进行分析。结果发病的13名工人均进食了被亚硝酸盐污染的水或食物,经及时治疗,中毒工人全部康复。中毒事件迅速控制。结论这是一起自来水被亚硝酸盐污染引起的急性食物中毒事件。应加强对生活饮用水的卫生监督与管理。     

P^H值及灭菌时间对甲硝唑降解产物的影响

本文采用比色法对甲硝唑注射液降解产物NO_2~-进行测定,找出最佳pH 及灭菌时间,以考察pH 和灭菌时间对甲硝唑降解产物的影响。结果表明,pH=5,灭菌15～30min 甲硝唑降解产物NO_2~-浓度最低。