Digital radiographic imaging system with multiple-slit scanning x-ray beam: preliminary report

A digital imaging system that employs a novel scanning x-ray tube, a multiple-slit assembly (MSA), and an image intensifier (II)-TV digital system is described. Use of the MSA can increase x-ray utilization by a factor of 100 over that obtained with single-slit systems. Scatter and veiling glare can be reduced substantially by synthesizing the final image from a number of multiple-slit images, resulting in improvement in contrast sensitivity. An experimental prototype system consisted of a conventional x-ray tube and an II-TV digital system used in conjunction with mechanical scanning of the MSA. Attenuation curves measured with an aluminum stepwedge showed that scatter and veiling glare were eliminated by this approach. Reconstructed images of phantoms were superior to images obtained with conventional wide-beam exposure. Physical parameters related to design of the scanning x-ray tube and a digital system for acquiring images of the chest are discussed.     

旋光活性内酯化合物的研究:(—)MALYNGOLIDE的全合成

以己二酸为起始原料,成功地合成了有手性季碳中心的内酯化合物(—)-Mialyngolide(1),其中关键的步骤采用手性相转移催化剂进行立体选择烷基化反应,此合成路线短,总收率为10.5%。     

旋光活性内酯化合物的研究：（—）MALYNGOLIDE的全合成

以己二酸为起始原料，成功地合成了有手性季碳中心的内酯化合物（—）－Ｍｉａｌｙｎｇｏｌｉｄｅ（１），其中关键的步骤采用手性相转移催化剂进行立体选择烷基化反应，此合成路线短，总收率为１０．５％。     

豆豉多糖对实验性糖尿病小鼠血糖的活性作用

目的:观察豆豉中的多糖类成分对正常小鼠和糖尿病小鼠血糖的影响,探讨其降血糖的活性作用。方法:实验于2006-03/06在华北煤炭医学院药学系实验室完成。选用雄性小白鼠130只,分为3部分进行实验。①治疗性给予豆豉多糖:取30只小鼠制作糖尿病模型。造模成功后随机平均分为模型组、低剂量给药组和高剂量给药组,另取10只作为空白对照组。低剂量和高剂量给药组小鼠分别灌胃豆豉多糖200mg/(kg·d)和400mg/(kg·d),模型组灌胃等体积的生理盐水,空白对照组不采取任何措施。给药4d和7d后测定各组小鼠的血糖水平。②豆豉多糖对正常小鼠血糖的影响:取30只小鼠随机平均分为对照组、低剂量给药组和高剂量给药组。低剂量和高剂量给药组小鼠分别灌胃豆豉多糖200mg/(kg·d)和400mg/(kg·d),对照组灌胃等体积的生理盐水,连续7d。末次给药2h后测定各组小鼠血糖水平。③预防性给予豆豉多糖:取30只小鼠随机平均分为对照组、低剂量给药组和高剂量给药组。低剂量和高剂量给药组小鼠分别灌胃豆豉多糖200mg/(kg·d)和400mg/(kg·d),对照组灌胃等体积的生理盐水,连续4d。灌胃结束后,腹腔注射四氧嘧啶200mg/(kg·d),3d后测定各组小鼠血糖及血清超氧化物歧化酶活性。结果:实验共纳入130只小鼠全部进入结果分析。①治疗性给予豆豉多糖对糖尿病模型小鼠血糖的影响:豆豉多糖灌胃后,模型组小鼠的血糖水平明显高于空白对照组(P<0.01)。给药4d时,高剂量和低剂量给药组与模型组比较,差异有显著性意义(P<0.01,0.05)。在给药7d后,随着多糖浓度的提高,血糖下降越明显,并呈现一定剂量-效应关系。②豆豉多糖对正常小鼠血糖的影响:豆豉多糖可明显降低正常小鼠的血糖水平(P<0.01)。③预防性给予豆豉多糖对糖尿病小鼠血糖及超氧化物歧化酶活性的影响:预防性给予小鼠豆豉多糖有明显的降血糖作用(P<0.01),说明豆豉多糖对糖尿病有一定的预防作用。与对照组比较,豆豉多糖可明显增加小鼠血清超氧化物歧化酶含量,提高超氧化物歧化酶活性。结论:豆豉多糖具有一定的降血糖作用。     

Breath odor evaluation by detection of volatile sulfur compounds – correlation with organoleptic odor ratings

Background:  Detection of oral volatile sulfur compounds (VSC) by gas chromatography (GC) is a widely used method for evaluating breath odor. Air aspirated from the mouth is injected into the GC column for analysis. To eliminate discrepancies caused by variations in operator sampling or injection techniques, a new GC system designed to aspirate breath samples directly into the GC was developed.
Objective:  A clinical study was performed to compare this new automated breath-sampling GC system to organoleptic evaluation by two trained odor judges.
Methods:  A randomized, two-cell, double-blind, parallel design was used in which subjects were tested before and 3 h after using either a mouthrinse containing zinc or a matching placebo rinse. Thirteen subjects used the zinc mouthrinse, and 12 used the placebo. Subjects with a wide range of VSC levels were studied. The average organoleptic ratings for each subject at each time-point were compared with the average VSC measurements made with the GC, and Pearson product–moment correlation coefficients between the corresponding GC and organoleptic measurements were determined.
Results:  The correlation between the GC and organoleptic assessment methods were highly significant ( P  ≤ 0.001) for: total VSC, 0.65; H₂S, 0.63; CH₃SH, 0.61; and (CH₃)₂S, 0.46. The correlation between the two judges was also highly significant (0.823, P  < 0.001).
Conclusion:  These results demonstrate the utility of the automated GC method for evaluating breath odor.