Color Stability of Dry Earth Pigmented Maxillofacial Silicone A-2186 Subjected to Microwave Energy Exposure

PURPOSE: The purpose of this study was to measure spectrophotometrically the color stability of pigmented A-2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5-year period of microwave sterilization. Materials AND METHODS: A-2186 silicone elastomer opacified with titanium white dry earth pigment, pigmented with 5 cosmetic dry earth pigment colors [no pigment (control) group (Pc), red (Pr), yellow ochre (Py), burnt sienna (Po), and a mixture of Pr + Py + Po color group (P3)], was used in this study. Each of the 5 experimental groups consisted of 5 specimens. All specimens were placed in a 250 ml glass beaker filled with 150 ml of water (replenished for each microwave exposure). An exposure of 6 minutes was used 18 times (simulating 1.5 years of microwave sterilization with one 6 minute exposure monthly). Reflectance values were measured by spectrophotometer. Three- and two-way analyses of variance with repeated measures were performed for the color difference (DeltaE*) with the factors of group/color/months, and group/months, respectively. Means were compared by Tukey Honest Significant Difference (HSD) multiple range test calculated at the 0.05 level of significance using SPSS. RESULTS: The trained human eye can detect color changes (DeltaE*) greater than 1.0. Most DeltaE* values of the red pigment group at all intervals and the mixed pigment group at 15- and 18- month intervals increased significantly greater than 1.0 (p < 0.001) compared with the control group. Yellow and burnt sienna groups remained the most color stable over time with DeltaE* values below 0.35. CONCLUSIONS: Lack of color stability of red dry earth pigmented A-2186 silicone maxillofacial elastomers was clinically significant after 12-month exposure to microwave energy as compared with yellow, burnt sienna, and opacified A-2186 dry earth pigments.     

Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potential

BACKGROUND: The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. METHODS: An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. RESULTS: In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments M(r) L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-gamma/IL-13 ratio and IFN-gamma/IL-4 ratio of CFSE(low) CD4(+) T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. CONCLUSION: Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein.     

微波与X线联合辐射对人体血液系统的影响

本文调查了微波与X线同时接触工人49名(联合组)、单微波接触工人48名(微波组)以及两者均不接触的工人46名(对照组)。联合组和微波组工人的微波辐射剂量每日平均约300μw/cm~2,联合组工人接触的X线剂量,每年小于5rem。结果显示:联合组中性粒细胞ACP、AKP活性以及中性粒细胞核棘突出现率均较微波组和对照组明显增高(P<0.01),糖原含量则较其它两组明显下降(P<0.01)。调查表明,低强度微波与低剂量X线联合辐射比单独微波辐射对人体的潜在危害更大。因此,对雷达等发射设备周围的工作人员,除必要的微波防护外。同时需要对X线进行防护。     

Combining microwave‐enhanced deuteriation reactions with parallel synthesis procedures

The development of combined microwave‐enhanced/parallel synthesis procedures and their application to the deuteriation of organic compounds via examples of solid‐state hydrogenation is reported. Other labelling procedures, such as solution state catalytic dehalogenations, hydrogenations as well as hydrogen isotope exchange reactions also benefit from the combined technology. Copyright © 2003 John Wiley & Sons, Ltd.     

狗前列腺微波热凝术后的组织学观察

用微波(频率2450MH_2(、单板天线(含测温装置)功率50W、中央定温60℃,进行狗前列腺热凝术。术后组织学观察,变化可分为三期:①凝固坏死期(0～3天);②炎症反应期(第6～15天);③组织自身修复期(第18～24天)。膀胱尿道造影及大体标本观察,尿道前列腺部明显扩大。提示局部、深部、温控微波热凝术,能有效地破坏前列腺组织,拓宽尿道前列腺部,而毗邻组织不受损伤。     

植酸磷的测定──离子交换法

介绍用离子交换法测定植酸磷的含量。对消化终点、最适的提取时间、离子交换树脂的分离效果进行了试验。黄豆粉、窝窝头、豆腐干植酸测得值的变异系数分别为２．１６％、４．９２％、１．７８％，回收率依次为１０３．３８％、１０２．８１％、１０３．４１％。植酸标准品的植酸含量理论值为５７．６４％，本法测定值为５５．２３％，相对误差为２．１４％。本法的精密度及准确度均符合要求。     

Noninvasive method for measuring the electrical properties of deep tissues using an open-ended coaxial probe

A new noninvasive method of measuring the structure and the electrical properties of bilayered biological tissues was evaluated as a potentially useful diagnostic means for detecting changes in subcutaneous tissues. First, the input impedance of an open-ended coaxial probe radiating into a bilayered model was calculated using a full-wave method, the results showed that the evanescen higher order modes do not have a significant influence on the reflection coefficient of muscle layer surface. Then, it was clearly proven that the phase shift and the modulus of the reflection coefficient of muscle layer surface depending on the frequency are useful to estimate the thickness of fat layer and the electrical properties of muscle respectively. The experimental results showed an excellent agreement with the theoretical relationship between the phase shift and the thickness. The sensitivity of estimation of the electrical properties of muscle was shown to be not enough for differentiating between normal and diseased deep tissue because of noises from the experimental systems.     

Gastrointestinal Contributions to the Postprandial Experience

Food ingestion induces homeostatic sensations (satiety, fullness) with a hedonic dimension (satisfaction, changes in mood) that characterize the postprandial experience. Both types of sensation are secondary to intraluminal stimuli produced by the food itself, as well as to the activity of the digestive tract. Postprandial sensations also depend on the nutrient composition of the meal and on colonic fermentation of non-absorbed residues. Gastrointestinal function and the sensitivity of the digestive tract, i.e., perception of gut stimuli, are determined by inherent individual factors, e.g., sex, and can be modulated by different conditioning mechanisms. This narrative review examines the factors that determine perception of digestive stimuli and the postprandial experience.     

EFFECTS OF MICROWAVE TREATMENT ON THE LYMPHOCYTESUBSETS IN CASES OF CHRONIC LYMPHEDEMA OF EXTREMITIES

R68llm6 Objectif Pour determiner l'dtat immunitaire des sons-groups l~taires T des malades aveclwtoeddlne chronique des extremitys et l' effet du traitement per micrreondes. ANt~ ie malades avec Iy7nphedimedes extradites(n = 20 ) et ies volontaires no~ux (n = 10 ) out ate studies per FITC on PHmerque MOAbs et cytometrie dcouleur double pour erminer ies changements des Phenotype l~taires T chez ies malades avec lpephoeddnZe aunt et aprdstraitement. ~flats Le rdsultat a montrd que ie pourc…     

微波治疗耳鼻喉科疾病疗效观察

探索耳鼻喉慢性炎症的简便有效疗法。方法：对１０２例病人表麻下用微波辐射探头定量向病 变组织输入电磁波。结果：随访观察半年以上,治愈率达８８．２４％,有效率达１００％。结论：此方法操作简便,疗 效好,病人痛苦小,值得临床推广。