过氧化苯甲酰对面粉中强化营养素含量的影响

为了解过氧化苯甲酰对强化面粉中营养素含量的影响 ,分别对过氧化苯甲酰含量为 0、6 0、12 0、2 4 0、6 0 0、12 0 0、180 0mg kg的营养强化面粉中的营养素进行检测 ,以确定添加不同剂量的过氧化苯甲酰对强化面粉中营养素含量的影响。结果显示 ,不同剂量的过氧化苯甲酰对Fe、Zn、Ca含量基本没有影响 ,对VB1、VB2 具有相对较弱的破坏作用 ,其损失低于 30 % ;在添加了高剂量增白剂的面粉中 ,烟酸、叶酸和VA的损失率分别在 30 %、5 0 %和 80 %以上 ,但在国家规定的增白剂使用限量 (≤ 6 0mg kg)范围内 ,增白剂对强化面粉中维生素的含量基本无影响。     

儿少卫生

042 8 0 6　学龄儿童维生素A营养状况及其与铁的相关性研究 /林晓明…∥卫生研究 2 0 0 3 ,3 2 (1 ) 1 3～ 1 6为观察学龄儿童维生素A(VA)营养状况、亚临床VA缺乏患病率及VA与铁的相关性 ,对北京房山山区1 0 1 2名 7～ 1 3岁学龄儿童进行膳食调查 ,随机抽取 3 0 5名儿童 ,静脉采血于避光下分离血清 ,用高效液相色谱法检测血清VA含量 ,同时测定其血清铁蛋白 (SF)、红细胞游离原卟啉 (FEP)和血红蛋白 (Hb) ,并依现行标准将其分为正常、铁缺乏 (ID)、红细胞生成缺铁期(IDE)与缺铁性贫血 (IDA)四组 ,观察VA与铁的相关性。结果显…     

学龄儿童维生素A营养状况及其与铁的相关性研究

为观察学龄儿童维生素A(VA)营养状况、亚临床VA缺乏患病率及VA与铁的相关性 ,对北京房山山区 1 0 1 2名 7～ 1 3岁学龄儿童进行膳食调查 ,随机抽取 30 5名儿童 ,静脉采血于避光下分离血清 ,用高效液相色谱法检测血清VA含量 ,同时测定其血清铁蛋白 (SF)、红细胞游离原卟啉 (FEP)和血红蛋白 (Hb) ,并依现行标准将其分为正常、铁缺乏 (ID)、红细胞生成缺铁期 (IDE)与缺铁性贫血 (IDA)四组 ,观察VA与铁的相关性。结果显示受检儿童膳食总能量、蛋白质和铁平均每日摄入量均达到膳食营养素的推荐摄入量 (RNI)及适宜摄入量 (AI) ,但平均每日VA摄入量为 (51 3 7± 2 86 1 ) μgRE ,仅占RNI的 59 7% ;血清VA平均含量为(1 0 1± 0 2 9) μmol L ,血清VA低于 1 0 5μmol L者占受检儿童的 59 0 % ,其中 1 2 8%的儿童血清VA低于0 70 μmol L ,正常及以上者仅占 41 0 %。并观察到血清VA含量与机体铁状况有相互随对方下降而减低的趋势。结果表明 ,该地区儿童存在明显的VA缺乏 ,应加强营养教育、改善不合理的膳食结构并通过适当的VA防治予以纠正     

牛初乳脂类的分析

本工作追踪分析了上海市母牛分娩后第1、5、8天(初乳)和第45天(成熟乳)泌乳脂类的成分。结果如下:1.在泌乳第1天,总脂、脂肪酸、甘油三酯、胆固醇和脂溶性维生素——(VA、VE、VD_3)以及β-胡萝卜素的含量最高,与成熟乳的相比有非常显著差别(P<0.01);2.从泌乳的第1至第8天,长链不饱和脂肪酸含量逐日下降,而脂溶性维生素急剧减少,有时低于第45天的含量;3.除雌二醇外,初乳脂中睾丸酮、孕酮和皮质醇含量均不超过成熟乳的水平。     

VA对小鼠胚胎中Hox-3.5表达的影响

目的 观察小鼠胚胎组织中Hox-3．5 mRNA的表达及VA缺乏和补充对其表达的影响。方法 初断乳的昆明小鼠，雌鼠60只随机分为正常对照组(N)、VA缺乏组(A)、妊娠第0d丰h充VA组(B)和妊娠第7d补充VA组(C)。N组饲含VA4000 U／kg饲料，A组饲VA缺乏饲料，B、C组在交配前饲VA缺乏饲料，在交配后分别于妊娠第0d或妊娠第7d饲含10000U／kg饲料。雄鼠饲以普通饲料。在妊娠第12d。剖腹取出胎鼠，采用原位杂交方法探测小鼠胚胎Hox-3．5 mRNA的表达，同时检查孕鼠血清VA水平。结果 在正常情况下，小鼠妊娠第12d胚胎组织Hox-3．5mRNA有表达，孕鼠血清VA缺乏时，妊娠第12d胚胎组织Hox-3．5mRNA的含量明显减少；妊娠第0d补充VA，Hox-3．5mRNA的含量与N组无差异；妊娠第7d补充，Hox-3．5mRNA的含量虽比A组增加，但仍明显低于N组。结论 VA可能在转录水平调控Hox-3．5的表达．     

VA对电离辐射损伤大鼠组织VE含量的影响

目的 :观察VA、VE联合应用对大鼠在电离辐射损伤中组织VE含量的变化 ,为治疗和预防自由基损伤相关疾病和抗氧化剂合理的应用提供理论依据。方法 :SD大鼠随机分成 8组 ,分别为阴性对照组、阳性对照组、VA(10mg·kg 1)组、VE(30mg·kg 1)组、和VA、VE联合用药 4组 (VE剂量固定在 30mg·kg 1,而VA剂量分别为 2 0、10、5、2 .5mg·kg 1) ,给药 6d后 ,除阴性对照组以外 ,其余各组均用 6 0　Co(6Gy)照射 ,3d后宰杀 ,并检测血清、脑及肝组织内的VA、VE含量。结果 :动物经辐照后 ,组织VA、VE含量均明显下降 (P <0 .0 5 )。单纯补充VA组的脑、肝组织中VA含量分别为 (14 .2 1± 1.6 8)、(86 .5 7± 3.97) μg·ml 1,较阳性对照组的 (8.31± 2 .0 6 )、(18.90±9.89) μg·ml 1明显升高 (P <0 .0 5 ) ;单纯补充VE组的血清、脑、肝VE含量分别为 (16 .5 7± 1.71)、(2 8.36± 3.98)、(41.6 3± 8.7) μg·ml 1,较阳性对照组的 (3.71± 1.12 )、(10 .96± 2 .74 )、(2 7.15±3.5 ) μg·ml 1明显升高 ;给予固定的VE剂量同时变动VA的干预剂量后 ,则血清、脑、肝组织VE含量随着VA剂量的增加呈现逐渐下降趋势 ,在VA为 10或 2 0mg时组织VE含量虽略回升 ,但仍低于初始剂量 (不含VA)组〔血清VE :(14 .0 4± 4 .6 9)vs(16 .5     

中青年人体内β-胡萝卜素转化为维生素A的效率

目的在前期对部分中老年农村居民进行了β胡萝卜素(βC)转化维生素A(VA)效率评价的基础上,再对10名农村中青年志愿者βC转化效率进行研究。方法使用稳定同位素稀释法对10名38～49岁健康志愿者(男5,女5)进行βC人体代谢实验。2周适应期和56天实验期内,志愿者接受常规膳食,避免大量VA和βC摄入以及烟、酒和营养制剂。实验第1天,给受试者含6mg氘标记βC(2H8βC)玉米油胶丸,随半流质早餐(脂肪热能比25%)一起摄入。实验第4天,受试者以同样方法摄入含3mg氘标记醋酸视黄醇(2H8RAc)油剂胶丸。实验第1天和第4天摄入标记物后0、3、5、7、9、11、13h时,第2、3、5、6、7、8、9、10、14、21、28、35、42、49和56天晨空腹时,采静脉血。用高效液相色谱仪(HPLC)测定血清类胡萝卜素成分浓度,使用气相质谱仪(GCMS)测定血清中不同来源视黄醇的同位素丰度。根据VA浓度和同位素丰度,描述标记VA在体内应答的血液动力学曲线。结果10名受试者口服2H8βC和2H8RAc后,血清中2H4视黄醇和2H8视黄醇的应答反应均非常明显;52天时血清中2H4视黄醇(来自2H8βC)的曲线下面积(AUC)平均为(1289±547)nmold;52天的2H8视黄醇(来自2H8RAc)的AUC平均为(3560±1058)nmold;以摄入的2H8RAc作为VA参照,计算来自口服2H8βC的2H4视黄醇平均为(3434±1449)nmold。βC转化为VA的转化系数平均为(3.89±2.76)∶1(摩尔单位)[范围是(2.00～9.61)∶1]或者(7.30±5.18)∶1(质量单位)[范围是(3.76～18.05)∶1]。结论采用稳定同位素稀释技术,定量测定了10名中国农村中青年志愿者体内βC转化为VA的效率,按质量单位计其转化比值平均为7.30∶1。     

北京市婴幼儿血清维生素A及母乳与鲜牛乳维生素A含量的调查

测定北京城区与近郊区163例1(1/2)岁以下牛乳喂养儿血清维生素A(VA),发现城区小儿高于郊区,未添加VA 制剂小儿56.85%血清VA 含量不足(<30μg/dl),4例添加VA 制剂过多致血清VA 过高(>10μg/dl)。测定623例正常足月新生儿血清VA,83.63%低于30μg/dl,60.19%低于20μg/dl。测21例42天母乳喂养儿与母血清VA 及母乳VA 含量,母血清VA 高于小儿,母乳居中。初乳VA 浓度高于成熟乳,母乳VA 含量哺乳后高于哺乳前。鲜牛奶中VA 含量冬春季略低于夏季,皆较低。为了解决牛乳喂养儿VA 不足与少数小儿VA 过量问题,北京1987年开始制造了维生素AD 强化牛奶,初步观察预防VA 缺乏与过量皆有满意的效果。     

不同剂量维生素A强化饼干对学龄前儿童健康影响的研究

【目的】　比较三种不同剂量强化维生素A(VA)对改善学龄前儿童维生素A和铁营养状况的效果 ,探索预防VA缺乏性疾病 (VADD)的强化饼干的理想剂量。　【方法】　将 75 3名观察对象随机分为 4组 ,前两组分别给3 0 %RNI和 10 0 %RNIVA强化饼干每天一次 ,后两组分别每周给VA2万IU强化饼干一次及补充VA2 0万IU胶丸一次 ,除 3 0 %RNI组补充 9个月外 ,其余三组补充 3个月。干预前后观察血清VA、Hb、血清前白蛋白 (PA)、血清视黄醇结合蛋白 (RBP)、身高和体重的变化。　【结果】　干预前后 ,各组儿童VADD和贫血的检出率明显降低 (P <0 .0 5 ) ;补充 3月后自身对照除 3 0 %RNI组PA和Hb外 ,四组其余指标均明显升高 (P <0 .0 5 ) ;组间比较 ,2万IU组血清VA升高幅度明显大于其余组 ,3 0 %RNI组Hb、PA和身高的增加幅度明显小于其它组 (P <0 .0 5 ) ;补充 9月后 ,3 0 %RNI组Hb和PA的升高明显大于其余组 (P <0 .0 5 )。　【结论】　补充三种不同剂量VA强化饼干和 2 0万IUVA胶丸 ,均可明显改善VA和铁营养状况 ,长期补充 ,3 0 %RNI和 10 0 %RNI强化剂量可能更佳     

儿童维生素A缺乏与感染性疾病的关系

[目的]了解儿童血清维生素A缺乏(vitamin A deficiency,VAD)与感染性疾病的关系. [方法]在避光条件下采集儿童指血、分离血清,以严格的质量控制,用微量荧光法检测血清维生素A(vitamin A,VA)浓度. [结果]两周内不同地区儿童发热率、急性呼吸道感染(ARI)、腹泻,发病率随血清VA缺乏率的增加而增加;儿童平均血清VA的含量随发热率、发病率的增加而下降. [结论]我国儿童血清VA含量低、缺乏率高的儿童不论个体或群体都表现为易于发生急性感染疾病,VAD是引起儿童易于发生急性感染性疾病的重要原因之一.     

维生素A强化食用油干预对少年儿童免疫功能的改善作用

目的:观察维生素A(VA)强化食用油营养干预对少年儿童免疫功能的改善作用。方法:在四个不同地区选择VA缺乏的小学生作为研究对象,用VA含量为7500μg/kg的食用油对受试儿童进行5个月营养干预,观察血清VA水平、免疫球蛋白(IgA,IgG,IgM)和补体C3含量的变化。结果:干预组儿童的血清VA水平明显高于对照组,血清IgA和补体C3含量得到显著改善,但IgG,IgM含量与对照组未见明显差别。结论:VA强化食用油可以有效改善儿童的VA营养状况,提高其免疫功能。     

Estimation of effective day length at any light intensity using solar radiation data

The influence of day length on living creatures differs with the photosensitivity of the creature; however, the possible sunshine duration (N(0)) might be an inadequate index of the photoperiod for creatures with low light sensitivity. To address this issue, the authors tried to estimate the effective day length, i.e., the duration of the photoperiod that exceeds a certain threshold of light intensity. Continual global solar radiation observation data were gathered from the baseline surface radiation network (BSRN) of 18 sites from 2004 to 2007 and were converted to illuminance data using a luminous efficiency model. The monthly average of daily photoperiods exceeding each defined intensity (1 lx, 300 lx, … 20,000 lx) were calculated [defined as Ne(() (lux) ())]. The relationships between the monthly average of global solar radiation (Rs), N(0), and Ne(() (lux) ()) were investigated. At low light intensity (<500 lx), Ne(() (lux) ()) were almost the same as N(0). At high light intensity (>10,000 lx), Ne(() (lux) ()) and Rs showed a logarithmic relationship. Using these relationships, empirical models were derived to estimate the effective day length at different light intensities. According to the validation of the model, the effective day length for any light intensity could be estimated with an accuracy of less than 11% of the mean absolute percentage error (MAPE) in the estimation of the monthly base photoperiod. Recently, a number of studies have provided support for a link between day length and some diseases. Our results will be useful in further assessing the relationships between day length and these diseases.     

Vitamin A Fortification Quality Is High for Packaged and Branded Edible Oil but Low for Oil Sold in Unbranded,Loose Form: Findings from a Market Assessment in Bangladesh

Although mandatory fortification of oil with vitamin A is efficacious, its effectiveness can be compromised by suboptimal compliance to standards. In this study, we assessed (1) the availability of oil brands across the eight divisions of Bangladesh, (2) fortification quality (the extent to which vitamin A content is aligned with fortification standards) of oil brands and producers and (3) the market volume represented by available edible oil types. We visited different retail outlets in rural and urban market hubs to ascertain available oil brands and bulk oil types and collected samples. We used high-performance liquid chromatography to quantify average vitamin A content and compared them to the national oil fortification standards. Among the 66 packaged brands analyzed, 26 (39%) were not fortified, and 40 (61%) were fortified, with 28 (42%) fortified above the standard vitamin A minimum. Among the 41 bulk oil type composites analyzed, 24 (59%) were not fortified, and 17 (41%) were fortified, with 14 (34%) fortified below and 3 (7%) fortified above the standard minimum. Vitamin A fortification is high for packaged and branded edible oil but low for oil sold in unbranded, loose form. As bulk oil makes up a large proportion of the oil market volume, this means the majority of the oil volume available to the population is either not (25%) or fortified below the standard requirement (39%). Regulatory inspections of producers selling bulk oil should be prioritized to support and incentivize the industry to make all oil traceable and fortified to standard.     

稳定化的维生素A、B_2和C强化压缩饼干的人体效用及其贮存效果

将V_A包膜微粒,V_(B2)四丁酸酯及V_C磷酸酯镁强化到压缩并干中,通过人体试验证明它们具有普通V_AV_(B2)及V_C的生物效用。强化剂量为7500IUV_A,5.16mg V_(B2)四丁酸醋(=3mgV_(B2))及308mg V_C磷酸酯镁(=140mgV_C)。在7日试验期末,尿中V_(B2),V_C及血浆V_C强化者都显著地高于试验前及未强化者,血浆V_A水平无显著差别,由于机体肝中V_A有贮存,血浆V_A保持平稳,不受短期V_A不同摄取量的影响。 将此强化的干粮贮存于85％RH,32℃,20个月,保存率(％)分别为:包膜V_A76,V_C磷酸酯84,V_A14,V_C29;室温贮存2年,保存率(％)为:包膜V_A75—87,V_C磷酸脂96—100,V_A8,V_C25左右,V_(B2)四丁酸酯与V_(B2)基本上一致。二年贮存的并干中的V_C磷酸酯仍具有V_C的同样的生物作用。     

维生素A强化牛乳预防婴儿维生素A不足的效果观察

本文观察了出生至15个月食用维生素A强化牛乳(维生素A2000IU/L)629例,和食用普通牛乳或母乳834例小儿一年四季血清中维生素A浓度。结果表明,日食维生素A强化牛乳500ml或以上,不另加维生素A制剂,可预防维生素A不足与过量,并可治疗维生素A的缺乏。     

蓝光对大鼠焦虑、抑郁及睡眠的影响

目的 探究蓝光对SD大鼠焦虑、抑郁及睡眠的影响。方法 动物分为正常光照组、低（100 lx）、中（300 lx）和高（500 lx）剂量蓝光照射组;剥夺蓝光对照组和剥夺蓝光组6个组,低、中、高3个剂量照射组蓝光照射28 d,每天1 h,剥夺蓝光组采用去除蓝光的白光照明饲养28 d。用高架十字迷宫实验、强迫游泳实验及戊巴比妥钠睡眠实验分别观察蓝光照射及去除蓝光对大鼠焦虑、抑郁及睡眠的影响。结果 高架十字迷宫实验各项指标组间差异无显著性。蓝光照射中剂量组动物强迫游泳实验中不动时间减少（P ＜0.05）,剥夺蓝光导致不动时间延长（P ＜0.05）;中剂量组在戊巴比妥钠睡眠实验中大鼠睡眠时间延长（P ＜0.05）,剥夺蓝光对戊巴比妥钠睡眠实验结果无明显影响。结论 蓝光照射不影响大鼠的焦虑状态,300 lx蓝光照射对大鼠有抗抑郁及促进睡眠的作用,而剥夺蓝光会导致大鼠抑郁。     

Effect of heat treatment on the biological value of beta-carotene added to soybean cooking oil in rats

Vitamin A deficiency is one of the major nutritional problems in the world, most common in developing countries. Food fortification is a recognised approach to supply vitamins and minerals to needed populations. Vegetable cooking oils were previously suggested by us as a carrier for vitamin A fortification. Fortification of cooking oil with beta-carotene could also be a strategy to prevent vitamin A deficiency. The objective of this article is to start studies on the use of cooking soya oil as a vehicle for synthetic carotene, to evaluate its stability to heat treatment, and to test its bioavailability and bioconversion to vitamin A in rats. Batches of carotene-fortified soybean oil were prepared, containing 2, 4 and 8 RE/g of diet. Some of them were heated to test its stability. At 100 degrees C there was no loss of carotene, at higher temperature carotene retention was 65%. The bioavailability and bioconversion of beta-carotene added to soybean oil was measured through feeding nursing rats and their pups method. Weight gain was good and plasma vitamin A increased significantly in all groups. Liver vitamin A values of rats fed diets with fortified soybean oil heated at 100 degrees C was similar to the 4 RE non-heated fortified oil group (0.72 +/- 0.06 and 0.64 +/- 0.08 mumol/g, respectively). Heated at 170 degrees C the liver total vitamin A value was reduced (0.45 +/- 0.04 mumol/g), but kept bioavailable vitamin A equivalent to 2 RE (0.47 +/- 0.09 mumol/g). Bioconversion of beta-carotene to vitamin A was validated by the plasma and liver findings. beta-carotene added to soybean oil showed good stability to heat and its bioconversion to vitamin A was shown in rat assays. beta-carotene mixed well with edible soybean oil and the fortified cooking oil showed potential as a carrier to be used for the prevention of vitamin A deficiency.     

Gastrointestinal Vagal Afferents and Food Intake: Relevance of Circadian Rhythms

Gastrointestinal vagal afferents (VAs) play an important role in food intake regulation, providing the brain with information on the amount and nutrient composition of a meal. This is processed, eventually leading to meal termination. The response of gastric VAs, to food-related stimuli, is under circadian control and fluctuates depending on the time of day. These rhythms are highly correlated with meal size, with a nadir in VA sensitivity and increase in meal size during the dark phase and a peak in sensitivity and decrease in meal size during the light phase in mice. These rhythms are disrupted in diet-induced obesity and simulated shift work conditions and associated with disrupted food intake patterns. In diet-induced obesity the dampened responses during the light phase are not simply reversed by reverting back to a normal diet. However, time restricted feeding prevents loss of diurnal rhythms in VA signalling in high fat diet-fed mice and, therefore, provides a potential strategy to reset diurnal rhythms in VA signalling to a pre-obese phenotype. This review discusses the role of the circadian system in the regulation of gastrointestinal VA signals and the impact of factors, such as diet-induced obesity and shift work, on these rhythms.     

基于VO2薄膜相变的强光限幅机制与复合防护技术

目的：分析研究基于热致相变原理的VO2薄膜强光限幅机制及其激光防护复合技术。方法：对VO2薄膜强光限幅特性、作用机理、影响因素与相关技术进行分析,探讨强光限幅与激光防护的技术特点及其规律,建立VO2薄膜强光限幅复合防护技术模块。结果：介绍了强光限幅与激光防护的技术特征,提出以激光为代表的强光辐射光限幅复合防护技术,包括VO2薄膜的设计与制备,热致相变与光限幅性质,相变阈值和光损伤阈值,复合材料增强防护技术,强光限幅与复合防护性能测试。结论：VO2薄膜强光限幅与激光防护复合技术为强光辐射人眼及光电传感器的损伤防护和光限幅材料与光限幅器的设计制备提供了有效技术途径。     

TCDD对猕猴妊娠期及其妊娠结局的毒性影响

在雌猴妊娠第１２天采用灌胃法一次性给予ＴＣＤＤ,剂量为１．０、２．０、４．０ｕｇ／ｋｇ．ｂｗ,每个剂量组４个动物。对照组（７个动物）给予相同体积的溶媒（丙酮－色拉油）。结果发现母猴在染毒１０天后相继出现食欲下降、体重降低、脱毛、皮炎和贫血等中毒症状,染毒组１２只猴子有１０只在怀孕的第２２到３２天发生早期胚胎丢失,结果表明,低剂量ＴＣＤＤ可导致妊娠期猕猴出现中毒症状,并影响妊娠结局。