直接键连原子间的NMR偶合常数的自然杂化轨道研究V.~(13)C-~(13)C和~(13)C-~(31)P核自旋偶合常数~1J_(CC)和~1J_(CP)

在前文工作的基础上，结合ＭＮＤＯ／ＥＨＭＯ分子轨道方法和自然杂化轨道方法，具体计算了ＣＣ键和ＣＰ键的核自旋偶合常数．计算结果表明，１ＪＣＣ和１ＪＣＰ主要由成键原子的轨道杂化作用和键极性这两种结构因素所决定．为从简单价键理论角度解释和计算１ＪＣＣ和１ＪＣＰ值提供了简便直观的方法．     

具有切向控制的局部四点插值曲线设计方法

Ｎｉｒａ Ｄｙｎ等提出的四点插值法是一种典型的自由曲线离散造型方法，但该方法不能控制插值点的切向。本文利用薄板样很可能 量的极小化原理给出了具有切向控制的四点分插值条件。用户可以方便地交互控制任一插值点的切向，使得四点插值法更为有效和实用。     

Simultaneous determination of cyanide and carbonyls in cyanogenic plants by gas chromatography-electron capture/photoionization detection

A new method to simultaneously detect cyanide and carbonyl compounds arising from cyanogenic glycosides in plants is described. A portable gas chromatograph.housing two detectors using a single carrier gas is employed to measure the carbonyl compounds (photoionization detector) and cyanide as its cyanogen chloride derivative (electron capture detector) from the headspace of a plant sample. This method affords in-field, rapid screening of plants to determine cyanogenicity. Good agreement was seen between this method for cyanide determination and two traditional field cyanide test kits. Detection of both the cyanide and the carbonyl compound(s) allows for confirmation of the presence of cyanogenic glycosides and eliminates the problem of false positives often seen in traditional cyanide test kits. Gas phase limits of detection for cyanide, acetone, butanone, and benzaldehyde were 69, 41, 105, and 0.39 parts per billion by volume (ppbv), respectively, allowing sensitive detection of cyanogenic glycoside breakdown products. The method's utility for screening cyanogenic plants is demonstrated, and it should be useful for screening cyanogenic foodstuffs to determine suitability for consumption.     

Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments

Background  

Dentin sialophosphoprotein (Dspp) is a multidomain, secreted protein that is critical for the formation of tooth dentin. Mutations in DSPP cause inherited dentin defects categorized as dentin dysplasia type II and dentinogenesis imperfecta type II and type III. Dentin sialoprotein (Dsp), the N-terminal domain of dentin sialophosphoprotein (Dspp), is a highly glycosylated proteoglycan, but little is known about the number, character, and attachment sites of its carbohydrate moieties.