饮食与癌症

“祸从口出,病从口入”,饮食不当是致癌的一大原因。是否有饮食预防癌症的办法呢?目前尚不敢肯定,但至少注意饮食可以减少患癌的机会。 1 饮食预防癌症的措施: 1.1 少吃或不吃熏制食品。因为此类食物含有亚硝酸盐(一类致癌物质)。     

饮食与癌症

在各类癌症患者中约有50％的妇女和30％的男人都与所处的环境因素有关,而在这些因素中主要的是食物。近来,值得关注的因素还在增加,各种不同的食品添加剂可能与某些癌症发生率的上升有关,通常使用的食品添加剂如糖精、红色染料2号和亚硝酸盐都是包括在内的致癌因素。此外,被污染的食物也有增加,如被农药残留物或工     

饮食与癌症

<正> 在各类癌症患者中约有50％的妇女和30％的男人都与所处的环境因素有关,而在这些因素中主要的是食物。近来,值得关注的因素还在增加,各种不同的食品添加剂可能与某些癌症发生率的上升有关,通常使用的食品添加剂如糖精、红色染料2号和亚硝酸盐都是包括在内的致癌因素。此外,被污染的食物也有增加,如被农药残留物或工      

癌症与饮食

据统计全世界每年患癌症的达500万人,有200万人因癌症死亡.癌症如此严重地威胁人类的健康,促使医学家对癌症的病因进行深入探索.“病从口入”本来是人们对许多传染病、特别是消化道传染病致病原因的精辟总结.但近年来医学界逐步发现癌症与饮食也有密切关系,因此“病从口入”也和癌症连系起来.     

饮食与癌症发病率

在正常情况下,人体内不会出现高半胱氨酸含量升高的情况,因为人体内不间断的反应可以把高半胱氨酸转化为另一种叫做蛋氨酸的物质,而该物质可以使基因中的DNA保持为正常的形态。 合理健康的膳食可以为人体提供维持这些反应正常所需要的若干物质。叶酸盐是一种B族维生素,它可以与高半胱氨酸结合生成蛋氨酸。体内叶酸盐的不足会降低这种反应并减少蛋氨酸的含量。这不利于DNA的生成和修补,而助长了非正常细胞的生成,进而发展成癌变。 即便是在对其它抗癌类营养物的摄取进行调节后,若干大型的研究已经显示,饮食中摄入高叶酸盐与低叶酸盐者相比较,前者患大肠腺瘤(即良性肿瘤)的危险性比后者低30～40％。研究提示,饮食中摄入叶酸盐较低者患乳腺癌、子宫癌、肺癌和食道癌的危险性也较高。     

营养与癌症

尽管现在还不清楚引起人类癌症的全部原因,但是多数科学家认为,人类癌症主要是由环境因素引起的,而在诸多的环境因素中膳食与营养占有重要的地位。大量的营养调查及研究表明,膳食不当也就是营养因素的摄入不当,可导致肿瘤的发生,而合理的膳食能降低肿瘤的发生率。一、热量流行病学调查表明,总热量的摄取与某些肿瘤的发病率呈正相关,尤其是热量来自脂肪和动物蛋白的比例增高时,肿瘤的发生率增高。每日总热量摄取从２７００千卡增加到３９００千卡时,结肠癌和直肠癌的死亡率上升２倍多。高热量饮食地区,女性乳腺癌发病率是低热量饮…     

营养失调与癌症

白质过多如果说人们对脂肪总是戒心大于放心的话，那么对蛋白质可称得上“一百个放心”了，因为人们从报刊上读到的都是为其评功摆好的文字，以及体内缺乏后的不良后果等。殊不知蛋白质也非完美无缺而“多多益善”，如果长时间过量摄人，同样是健康的破坏因素，甚至使你不知不觉患上癌症。这一点，美国癌症研究机构在20多年前就以老鼠为对象做过实验，他们分别喂以8％、22％、30％的酪蛋白饲料（此前均喂给具有强烈致癌性的曲霉素诱发癌症），结果蛋白质最低组的老鼠肝癌发病率为零，而最高组SO％的老鼠患了癌症。前不久，美国研究人员又以…     

果胶酶活力测定中酶活力与稀释倍数的研究

研究了果胶酶活力测定中酶活力与稀释倍数关系，确定了在用PEG／（NH4）2SO4双水相系统进行果胶酶提取分离过程中酶活力测定的最佳稀释倍数，为进一步研究建立了理论依据。     

THE RELATIONSHIP BETWEEN THE ATP CONTENT OF BARLEY AND VIABILITY

ATP, measured using a bioluminescence technique, is higher in viable barley than in dead grain. This is observed for both Spring and Winter varieties. More ATP is extracted from corns whose moisture content is increased, though increasing the moisture content of dead grain has no effect on the levels of ATP extracted. The ATP measurement method, as it stands however, is insufficiently discriminatory for the absolute selection of barleys at intake.     

酚类物质结构与其杀菌活性的关系

提出了分子中“局部偶极矩”的概念，并在ＤＰＳ／８计算机上用ＳＣＦ－ＣＮＤＯ／２法进行了局部偶极矩的计算，结果发现，酚类化合物的杀菌活性和该分子苯环上的局部偶极矩大小有关；所计算的近２０个分子，其局部偶极矩与酚系数皆呈单调关系     

非离子表面活性剂复配与浊点的关系

研究了不同非离子表面活性剂混合后对浊点的影响。结果表明：不同结构的非离子表面活性剂对浊点影响不尽相同。只有同系非离子表面活性剂混合后的浊点介于各单体之间并接近加合计算值,且混合溶液越接近理想表面活性剂溶液,与加合计算值越接近。烷基多苷（ＡＰＧ）对浊点基本无影响;多元醇型表面活性剂Ｔｗｅｅｎ－８０与Ｔｗｅｅｎ－６０使浊点略上升;Ｓｐａｎ－８０与单硬脂酸甘油酯使浊点略有下降;烷基醇酰胺６５０１使浊点上     

THE RELATIONSHIP BETWEEN HAZE AND THE SIZE OF PARTICLES IN BEER

Haze measurements have been obtained for suspensions of polystyrenelatex particles of known diameter using two light scattering instruments which measure at angles of 90° and 13° respectively. The results agree well with the theory of light scattering and demonstrate the significant effects of particle size and angle of detection upon the instrumental values for haze. This information has been used to correlate the particle size distributions of a number of beers, as measured by Coulter Counter, with the corresponding, measured haze values.     

RELATIONSHIP BETWEEN THE TEXTURE AND PECTIN CONSTITUENTS OF JAPANESE PEAR

The relationship between texture and pectin constituents and some related compounds of the Japanese pear (Pyrus serotina Render var. culta 'Housui') during fruit enlargement and ripening was studied. The modulus of elasticity, deformation ratio, and relaxation value from the flat plate compression test, and all the properties from the puncture test were affected by the pectin constituents, alcohol insoluble solids, and soluble solids. The hardness and deformation of the fruit obtained from the plate compression test might depend on the combination of the alcohol insoluble solids in fresh weight and weight of the fruit. The oxalate soluble pectin both in alcohol insoluble solids and in fresh weight affected the fruit texture more than the water soluble pectin. The solubitization of nonsoluble pectin to water soluble pectin appeared to influence the textural properties more than that of the nonsoluble pectin to oxalate soluble pectin. The puncture test was superior in analyzing the textural properties of the Japanese pear fruits with regard to changes in the pectin constituents.     

利用离子交换及微胶囊技术生产要素膳

以猪血浆蛋白为原料,经酸水解、离子交换树脂分离、纯化,制得含有18种氨基酸的混合物.将大豆油脂采用微胶囊包埋技术处理,制得粉末化微胶囊大豆油脂,将氨基酸混合物、粉末大豆油脂、碳水化合物、维生素及矿物质进行复配制得高脂肪要素膳.     

RELATIONSHIP BETWEEN FUSARIUM INFESTATION OF BARLEY AND THE GUSHING POTENTIAL OF MALT

Fifty barley samples, displaying a range of 0 to 100% kernels infested with Fusarium, were collected in North Dakota, South Dakota, and Minnesota during the harvest of 1994. Samples were micromalted, and the levels of the fungal metabolites, deoxynivalenol and ergosterol, were determined. Fusarium infestation and the levels of fungal metabolites were evaluated as predictors of gushing in laboratory trials. Malt samples which were infested with Fusarium or contaminated with the fungal metabolites exhibited a propensity to gush. However, only the levels of deoxynivalenol and ergosterol were found to be strongly correlated with the actual amount of gushing observed. This suggests that their production may parallel that of the component which actual causes gushing, and that screening barley and malt for these metabolites, may offer a means of reducing gushing problems in the brewery. Determination of deoxynivalenol is rapid, when it is present, and necessary because of food safety and malt quality concerns.     

RELATIONSHIP BETWEEN LEVELS OF GIBBERELLIC ACID AND THE PRODUCTION AND ACTION OF CARBOHYDRASES OF BARLEY

Different hydrolytic enzymes require different levels of gibberellic acid to induce their maximal production and release into the endosperm of barley. Barley-endo-β-glucanase requires a higher level of gibberellic acid to induce maximal production than does α-amylase. Although gibberellic acid also increases the level of barley endo-β-1,3 glucanase, this enzyme, unlike the barley-endo-β-glucanase, develops to significant levels when gibberellic acid is absent. In gibberellic acid-treated aleurone layers β-glucanases degrade the cell wall mainly to glucose. Xylose and cellobiose appear when the aleurone wall has undergone extensive enzymic hydrolysis. Laminaribiose and arabinose are found whether or not gibberellic acid is present in the medium. In addition to the degradation of the endosperm cell walls, β-glucanases may also play an important role in the release of enzymes from the aleurone into the endosperm during malting.     

麦芽糖产率与淀粉液化程度关系的研究

研究了麦芽糖的理论与淀粉液化程度的关系,当应用麦芽糖 生成酶可水解麦芽三糖时,麦 芽糖的产率为［０ ．９７７５ － ９ Ｄ Ｅ／（２０ － ２ Ｄ Ｅ）］ ×１００ ％ ;当所用麦芽糖 生 成 酶 不 能 水 解 麦 芽 三 糖 时, 麦 芽 糖 的 产 率 为［０ ．９３２５ － ２７／（２０ － ２ Ｄ Ｅ）］ ×１００ ％ 。理论关系式 与实验结果良好。