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1.
There have been periodic electronic news media reports of potential bioterrorism-related incidents involving unknown substances (often referred to as “white powder”) since the 2001 intentional dissemination of Bacillus anthracis through the U.S. Postal System. This study reviewed the number of unknown “white powder” incidents reported online by the electronic news media and compared them with unknown “white powder” incidents reported to the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Federal Bureau of Investigation (FBI) during a 2-year period from June 1, 2009 and May 31, 2011. Results identified 297 electronic news media reports, 538 CDC reports, and 384 FBI reports of unknown “white powder.” This study showed different unknown “white powder” incidents captured by each of the three sources. However, the authors could not determine the public health implications of this discordance.  相似文献   
2.
Four fluorescent fingerprint powders (RedWop?, GreenWop?, Basic Yellow?, and Yellow Powder?) were evaluated as a marker for blow fly larvae. Administration methods included ingestion (high vs. low concentration) or topical. Ingestion of high concentrations of Basic Yellow? and RedWop? caused higher larval mortality. Basic Yellow? delayed development and adult emergence while RedWop? and Yellow Powder? had a significant effect on particular stages of development, however, emergence time was not altered. Optimal administration is through ingestion at low concentration levels (<10%) or topically, with GreenWop? demonstrating minimal adverse effects. Optimum wavelength for discrimination between powders was 450 nm. This research can aid in investigative training to increase visibility of larval and pupal blow flies. It can also be used in entomological studies to differentiate between larval blow flies (or other dipteran) species or individuals to further understand complex interactions and behavior during larval development.  相似文献   
3.
利用纳米粉体显现光滑客体汗潜指纹   总被引:3,自引:0,他引:3  
纳米粉体材料色彩丰富,且对各种客体都有一定的吸附能力。这里介绍了应用吹显技术对14种纳米粉体材料在玻璃、瓷器、油漆等不同光滑客体表面遗留汗潜指纹的显现方法,实验证明显现效果较好。  相似文献   
4.
目的 制备葛根素纳米冻干粉,并对其进行质量评价。方法 通过对冻干保护剂、冻干时间、预冻温度等的单因素考察,选择葛根素纳米冻干粉的最佳制备工艺,并对冻干粉的理化性质、纳米形态和质量进行评价。结果 葛根素纳米粉体的最佳成型工艺为:以甘露醇为冻干保护剂,置-80 ℃冰箱中预冻12 h,然后在-40 ℃、5 Pa下真空冷冻干燥36 h升华水分。制备的纳米粉体具有良好的溶解性能,平均粒径为108 nm,表面电位为-24.3 mV,平均含量约为140 mg/g。结论 采用冻干技术制备葛根素纳米粉体技术可行。  相似文献   
5.
利用傅里叶红外图像系统,采用单点模式对收集到的八种品牌激光打印机墨粉色痕进行红外扫描,采集样品红外光谱,并对其中两种样品红外光谱进行二阶导数运算,得到对应的二阶导数光谱。实验表明,该方法可有效区分不同品牌激光打印机墨粉色痕,并可为其他书写材料无损检验鉴定提供借鉴。  相似文献   
6.
This study takes the first step toward in situ analysis of powder drugs which does not require any alteration of the samples. A fast, inexpensive analytical method based on reflectance near-infrared (NIR) spectrometry and multivariate calibration was applied. A diode-array fiber-optic portable spectrometer in the 900-1700 nm range was employed. Samples were laboratory-prepared ternary powders (diacetylmorphine, caffeine, and paracetamol). Partial least squares regression was applied. The choice of the standard samples for calibration and validation was performed through a D-optimal experimental design. The explained variance was higher than 90%, and the relative root mean square errors were <2%. The number of principal components (6) was very low when compared with the number of raw variables (356 absorbance values). Response plots showed slopes and intercepts were very close to optimal values. Correlation coefficients ranged between 0.909 and 0.989. The method here proposed proved to be competitive with Fourier transform NIR spectrometry.  相似文献   
7.
目的 观察加减参苓白术散治疗儿童特应性皮炎脾虚蕴湿证的临床疗效.方法 将40例特应性皮炎脾虚蕴湿证患儿随机分为治疗组和对照组,每组20例.治疗组给予加减参苓白术散及地氯雷他定糖浆口服;对照组仅口服地氯雷他定糖浆.两组均外涂玉泽皮肤屏障修护乳.采用特应性皮炎评分(scoring atopic dermartitis,SCORAD)分别于治疗前,治疗2、4周后对两组患儿的临床症状及体征进行评分,判定临床疗效,并于患儿治疗前和治疗4周后检测外周血嗜酸性粒细胞数(eosinophils,EOS).结果 治疗4周后,两组患儿SCORAD、EOS计数均显著降低(P<0.05),且治疗组SCORAD评分、EOS计数均明显低于对照组(P<0.05).治疗组临床疗效显著优于对照组(P<0.05),治疗组的复发率显著低于对照组(P<0.05).结论 加减参苓白术散治疗儿童特应性皮炎脾虚蕴湿证具有良好疗效,能够改善临床症状.  相似文献   
8.
Carbon‐based materials are often used as matrices for matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) and its imaging (MALDI‐MSI). However, researchers have refrained from using carbon‐based fingerprint powder (CFP) as a matrix due to high background and contamination. In this work, the compatibility of CFP is reevaluated with MALDI‐MSI using a high‐resolution mass spectrometer (HRMS) and compared to traditional organic matrices. Relevant fingerprint compounds were easily distinguished from carbon cluster peaks when using HRMS. For fair comparison, half of a fingerprint was dusted with CFP while the other half was dusted with traditional organic matrices. All compounds studied had comparable, or higher, signal‐to‐noise (S/N) ratios when CFP was used as the matrix. Additionally, chemical image qualities closely followed the trend of S/N ratios. CFP proved to be an effective one‐step development and matrix application technique for MALDI‐MSI of latent fingerprints, when carbon cluster peaks are well separated by a HRMS.  相似文献   
9.
Abstract: Pyrodex ® and Triple Seven ® are black powder substitutes that often find use as fillers in improvised explosive devices, such as pipe bombs. These propellants have essentially the same overall appearance and oxidizers, but different fuels. For example, Pyrodex ® contains sulfur, sodium benzoate, and dicyandiamide (DCDA), whereas Triple Seven ® lacks sulfur but also contains 3‐nitrobenzoic acid. In this method, intact particles and postblast solid residues were reacted with bis(trimethylsilyl)trifluoroacetamide + 1% trimethylchlorosilane in acetonitrile for 30 min at 60°C. The resultant trimethylsilyl derivatives of the organic fuels were then analyzed by gas chromatography–mass spectrometry. Each derivative was clearly resolved from other components, and high‐quality mass spectra were obtained. In addition, characteristic fragments resulting from loss of a methyl radical from the molecular ion (m/z 163 for sulfur, m/z 171 for DCDA, m/z 179 for benzoic acid, and m/z 224 for nitrobenzoic acid) were able to be monitored.  相似文献   
10.
Aluminum (Al) powders are commonly used in improvised explosive devices as metallic fuels, a component of explosive mixtures. These powders can be obtained readily from industrial‐scale and consumer products, and produced using unsophisticated “kitchen chemistry” techniques. This research demonstrates the potential of automated particle micromorphometry for comparisons between known source and questioned Al powders recovered from IEDs, as well as for insight into the method of Al powder manufacture. Al powder samples were obtained from legitimate manufacturers, and 56 samples were produced “in‐house” from Al‐containing spray paints and ball‐milled Al foils. Transmitted light microscope images of Al powder particles were acquired using an automated stage with automated z‐focus; 17 size and shape parameters were measured for all particles. Approximately 37,000–2,500,000 particles/sample were analyzed using an open‐source statistical package with customized code. Dimensionality reduction was required for processing the large datasets: eight of the 17 measured variables were selected based on inspection of the correlation matrix. Data from four subsamples from each of the 56 samples produced using “in‐house” methods were analyzed using ANOVA to assess the within‐ and between‐sample variation. High within‐sample variation was noted; however, ANOVA and post‐hoc Tukey's honestly significant difference (HSD) tests demonstrated that the between‐sample variation was substantially larger than the within‐sample variation. Each sample could be differentiated from all other samples in the test set. Future experiments will focus on ways to reduce the within‐sample variation, and additional statistical and microanalytical methods to classify sources and confidently constrain the method of Al powder manufacture.  相似文献   
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