有关糖类的文献

建立假设检验：一、通过文献的研究类型建立假设该文献是以原发性肝癌患者为研究对象的现场研究。因现场研究混杂因素不易控制，应辅以动物实验的实验研究。建立假设：由该文献可了解到通过现场研究发现糖尿病与原发性肝癌危险因素，从而假定通过动物实验也可得到相同结论。标题：糖尿病大鼠诱发肝癌的实验研究立项依据：有研究资料表明，在胆红素脑病时，胆红素可导致神经细胞凋亡。为此，我们提出胆红素诱导肝细胞凋亡的假设。目前，未见胆红素诱导肝细胞凋亡的报道。研究背景：在重症肝炎时期，当血清胆红素含量升高时，血清丙氨酸转氨酶活性不仅不升高，反而会逐渐下降，此即“胆酶分离”现象。二、通过文献的设计类型建立假设本文献为完全随机设计，完全随机设计的研究资料表明糖尿病可能是原发性肝癌的危险因素。至今未见同源配伍设计的临床观察报道糖尿病是原发性肝癌的危险因素。为此我们建立糖尿病与肝癌的发生有密切关系假设。 每年随诊100例糖尿病患者—————————>观察肝癌发生情况 观察10年，每年1次三、通过实验三要素建立假设（处理因素，实验对象，实验效应）本文以高血压作为处理因素，得出糖尿病可能是原发性肝癌的危险因素。经查阅文献未见有高血压与原发性肝癌发生的报道。为此，我们建立高血压与原发性肝癌发生有关的假设。进行高血压与原发性肝癌的研究。高血压患者50人 每年随访 ————>原发性肝癌发病情况正常人群50人

Sugar is an informal term for a class of edible crystalline substances, mainly sucrose, lactose, and fructose[1] characterized by a sweet In food, sugar almost exclusively refers to sucrose, which primarily comes from sugar cane and sugar Other sugars are used in industrial food preparation, but are usually known by more specific names—glucose, fructose or fruit sugar, high fructose corn syrup, Excessive consumption of sucrose has been associated with increased incidences of type 2 diabetes, obesity and tooth [2]Sugar consumption varies from country to country; Brazil has the highest per capita production and India the highest per-country [3]Contents [hide]1 History 2 Terminology 1 Popular 2 Culinary/nutritional 3 Baking weight/mass volume relationship 4 Purity standards 3 Chemistry 1 Natural polymers of sugars 4 Etymology 5 See also 6 Notes 7 References 8 External links History This section requires Sugar was not plentiful or cheap in early times—honey was more often used for More recently it is manufactured in very large quantities in many countries, largely from sugar cane and sugar TerminologyPopularThe term sugar usually refers to sucrose, which is also called "table sugar" or "" Sucrose is a white crystalline Sucrose is the most popular of the various sugars for flavoring, as well as properties (such as mouthfeel, preservation, and texture) of beverages and Manufacturing and preparing food may involve other sugars, such as fructose, generally obtained from corn (maize) or from Culinary/nutritionalIn culinary terms, the foodstuff known as "sugar" delivers a primary taste sensation of Apart from the many forms of sugar and of sugar-containing foodstuffs, alternative non-sugar-based sweeteners exist, and these particularly attract interest from people who have problems with their blood sugar level (such as diabetics) and people who wish to limit their calorie-intake while still enjoying sweet Both natural and synthetic substitutes exist with no significant carbohydrate (and thus low-calorie) content: for instance stevia (an herb), and saccharin (produced from naturally occurring but not necessarily naturally edible substances by inducing appropriate chemical reactions)The World Health Organisation and the Food and Agriculture Organization of the United Nations expert report (WHO Technical Report Series 916 Diet, Nutrition and the Prevention of Chronic Diseases)[citation needed] defines free sugars as all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and fruit This includes all the sugars referred to The term distinguishes these forms from all other culinary sugars added in their natural form with no refining at Baking weight/mass volume relationshipDifferent culinary sugars have different densities due to differences in particle size and inclusion of The Domino Sugar Company has established the following volume to weight conversions:Brown sugar 1 cup = 48 teaspoons ~ 195 g = 88 oz Granular sugar 1 cup = 48 teaspoons ~ 200 g = 06 oz Powdered sugar 1 cup = 48 teaspoons ~ 120 g = 23 oz Bulk Density[4]Dextrose Sugar 62 g/ml Granulated Sugar 70 g/ml Powdered Sugar 56 g/ml Beet Sugar 80 g/ml Purity standardsThe International Commission for Uniform Methods of Sugar Analysis sets standards for the measurement of the purity of refined sugar, known as ICUMSA numbers; lower numbers indicate a higher level of purity in the refined [5]ChemistryMain article: Carbohydrate Magnified crystals of refined sugar Grainier, raw Scientifically, sugar loosely refers to monosaccharide or Monosaccharides are also called "simple sugars," the most important being Almost all sugars have the formula CnH2nOn (n is between 3 and 7) Glucose has the molecular formula C6 H12O The names of typical sugars end with "-ose," as in "glucose", "dextrose", "" Sometimes such words may also refer to any types of carbohydrates soluble in The acyclic mono- and disaccharides contain either aldehyde groups or ketone These carbon-oxygen double bonds (C=O) are the reactive All saccharides with more than one ring in their structure result from two or more monosaccharides joined by glycosidic bonds with the resultant loss of a molecule of water (H2O) per Monosaccharides in a closed-chain form can form glycosidic bonds with other monosaccharides, creating disaccharides (such as sucrose) and polysaccharides (such as starch) Enzymes must hydrolyse or otherwise break these glycosidic bonds before such compounds become After digestion and the principal monosaccharides present in the blood and internal tissues include glucose, fructose, and Many pentoses and hexoses can form ring In these closed-chain forms, the aldehyde or ketone group remains unfree, so many of the reactions typical of these groups cannot Glucose in solution exists mostly in the ring form at equilibrium, with less than 1% of the molecules in the open-chain Natural polymers of sugarsBiopolymers of sugars are common in Through photosynthesis plants produce glucose, which has the formula C6H12O6, and convert it for storage as an energy reserve in the form of other carbohydrates such as starch, or (as in cane and beet) as sucrose (table sugar) Sucrose has the chemical formula C12H22O Starch, consisting of a two different polymers of glucose, is a readily degradable chemical energy stored by cells, convert to other types of Cellulose is a polymer of glucose used by plants as structural DNA and RNA are built up of the sugars ribose and Sucrose: a disaccharide of glucose (left) and fructose (right), important molecules in the The sugar in DNA, deoxyribose has the formula C5H10Oant feeding on sugar crystalsEtymologyThe etymology reflects the spread of the The English word "sugar" originates from the Arabic word سكر sukkar,[6] itself derived from Sanskrit शर्करा S[7] It came to English by way of French, Spanish and/or Italian, which derived their word for sugar from the Arabic and Persian شکر shakar (whence the Portuguese word açúcar, the Spanish word azúcar, the Italian word zucchero, the Old French word zuchre and the contemporary French word sucre) (Compare the OED) The Greek word for "sugar", Ζάχαρη zahari, means "pebble" Note that the English word jaggery (meaning "coarse brown Indian sugar") has similar ultimate etymological origins (presumably in Sanskrit)See also