Is the reliability of a visual analog scale higher than an ordinal scale? An experiment with the GRBAS scale for the perceptual evaluation of dysphonia

Perceptual evaluation of 14 pathological voices was performed by 29 listeners using the GRBAS scale. To evaluate scale effects on the judgments, 2 versions of the scale were presented: the original 4-point scale and a visual analog scale. Each listener used the same voice samples for both versions of the scale with an interval of 2 weeks. Agreement was found to be higher with the original 4-point scale than with the visual analog version for all scale items G, R, B, A and S. Although a visual analog scale seems to enable a finer judgment of voice quality, this study showed that, with increased freedom of judgment, the interrater agreement decreased considerably. Therefore, we recommend the use of the original 4-point version of the GRBAS scale.     

A simple visual method for DNA detection based on the formation of gold nanoparticles

A simple visual method for DNA detection during the formation of gold nanoparticles (AuNPs) was developed based on different electrostatic properties of single strand DNA (ssDNA) and double strand DNA (dsDNA). Since the ssDNA is easy to bind to AuNPs due to its exposed bases which could prevent salt-induced aggregation of AuNPs. The dsDNA always present negative charge because its negatively charged phosphate backbone is exposed. In this case, the dsDNA could disturb the adsorption between dsDNA and AuNPs and result in non-aggregation of AuNPs. After hybridization, chloroauric acid and ascorbic acid were added to the mixture solution, and the solution changed to red immediately and turned to purple in 10 min in the present of target DNA. TEM results confirmed that the change of color stemed from aggregation of AuNPs. In order to obtain accurate results by naked eye, the DNA detection assay should be conducted under pH 7.0.     

Distinguishing and quantification of the human visual pathways using high-spatial-resolution diffusion tensor tractography

Quantification of the living human visual system using MRI methods has been challenging, but several applications demand a reliable and time-efficient data acquisition protocol. In this study, we demonstrate the utility of high-spatial-resolution diffusion tensor fiber tractography (DTT) in reconstructing and quantifying the human visual pathways. Five healthy males, age range 24–37 years, were studied after approval of the institutional review board (IRB) at The University of Texas Health Science Center at Houston. We acquired diffusion tensor imaging (DTI) data with 1-mm slice thickness on a 3.0-Tesla clinical MRI scanner and analyzed the data using DTT with the fiber assignment by continuous tractography (FACT) algorithm. By utilizing the high-spatial-resolution DTI protocol with FACT algorithm, we were able to reconstruct and quantify bilateral optic pathways including the optic chiasm, optic tract, optic radiations free of contamination from neighboring white matter tracts.     

Voice characteristics, effects of voice therapy, and long-term follow-up of contact granuloma patients

This study evaluates the laryngoscopic findings and voice characteristics of male contact granuloma patients before and after voice therapy and at a follow-up about 9 years later. Pre- and posttherapy recordings as well as follow-up recordings were made for 19 granuloma patients. Pretherapy revealed the most salient perceptual voice characteristics were low pitch, monotony, and a high degree of vocal fry and hyperfunction. Interjudge reliability for these traits was high. Immediately following therapy the healed patients (n = 10) had a decrease in hyperfunction, vocal fry, and monotony, while the unhealed patients (n = 9) had an increase in hyperfunction and vocal fry decreased only marginally. Monotony decreased significantly in this group. As regards the acoustic analyses, no significant differences were found in mean fundamental frequency (F₀) or perturbation. At the follow-up assessment 4 patients had granuloma while 15 had normal laryngeal status. Perceptually their voice characteristics resembled those pretherapy independently of the laryngeal findings. The results suggest that reduced hyperfunction and decreased vocal fry may create better circumstances for the healing process at the posterior glottis.     

基于碳量子点和罗丹明B的新型比率荧光试纸片检测水中Hg(Ⅱ)

水环境中Hg(Ⅱ)的污染对生态环境和人类健康危害极大,目前Hg(Ⅱ)的检测主要有原子光谱/质谱和电化学等方法,但存在检测仪器昂贵、操作繁琐及前处理复杂等缺点,难以在日常水环境中微量Hg(Ⅱ)现场检测的应用。因此,建立一种灵敏、准确、快捷和经济的水中Hg(Ⅱ)检测方法具有重要意义。试纸法是将普通的化学反应从玻璃仪器转移到试纸上进行的一种快速检测方法,利用试剂与目标物之间产生的化学反应,通过颜色的变化可对目标物进行定性或半定量检测,具有操作简便、快速等优点。碳量子点是一类粒径小于10 nm的碳基纳米材料,具有优异的荧光性能、较低的毒性和较高的化学稳定性。利用Hg(Ⅱ)对碳量子点的荧光具有灵敏和高效的猝灭作用,构建了一种双色比率荧光试纸片用于快速检测水中微量Hg(Ⅱ)的含量。其中,采用氮掺杂水溶性碳量子点（NCDs）作为荧光响应信号、罗丹明B（RhB）作为荧光内标信号,在单一波长（355 nm）激发下产生位于440和580 nm的双色荧光发射峰。当体系加入不同浓度Hg(Ⅱ)后,NCDs表面官能团与Hg(Ⅱ)之间的静电作用和金属配位协同作用使荧光发生猝灭,而RhB的荧光信号保持不变,利用440和580 nm双色荧光信号或其强度的比值（F₄₄₀/F₅₈₀）,可实现对微量Hg(Ⅱ)的快速检测。实验对检测条件进行了优化,结果表明在HAc-NaAc缓冲液浓度为1 mmol·L-1、pH为7的条件下,F₄₄₀/F₅₈₀值与Hg(Ⅱ)浓度（0～3 μmol·L-1）呈现良好的线性关系,线性方程为F₄₄₀/F₅₈₀=-0.785 2ｃ_Hg(Ⅱ)+3.103 8,相关系数r＞0.99,以3倍标准偏差计算的检出限为2.7 nmol·L-1(n=9)。对湖水与自来水中Hg(Ⅱ)进行加标回收实验,其加标回收率在91.9%～117.9%之间,说明该方法灵敏、准确,能用于水中Hg(Ⅱ)的检测。同时,将NCDs和RhB浸渍于尼龙片上构建了双色比率荧光检测试纸片,在紫外灯（365nm）照射下可观测到试纸发射淡蓝紫色荧光。而随着Hg(Ⅱ)浓度的增加,荧光颜色从淡蓝紫色到橙色发生变化,每次检测时间只需3分钟,裸眼可检出Hg(Ⅱ)浓度低至10 nmol·L-1,实现了对水中微量Hg(Ⅱ)的灵敏、快速检测。此外,该方法对Hg(Ⅱ)的检测表现出良好的特异性。因此,基于碳量子点和罗丹明B构建的双色比率荧光试纸片具有携带方便、操作简单,以及灵敏和快速等优点,为水中微量Hg(Ⅱ)的快速检测提供了新的方法和思路。     

光幕性能测试系统数学建模和软件设计

光幕性能测试系统主要是为研究更大规模的光幕靶和密集度靶提供必要的数据准备和理论基础的。研制出了用于探测光幕靶、密集度靶等光幕面内光能分布情况(光强度、一致性、均匀性)的测试仪器。光幕光能量数学模型的建立和光幕性能测试软件是非常重要的。为了了解其功能对光幕发光的情况,利用Visual C++6.0开发工具设计了一个光幕性能测试系统软件,实现了光能分布情况的采集和处理。文章从数学建模及软件设计两部分着重介绍了该系统的设计过程。测试结果表明,基本符合理论分析的光场能量计算公式,为光幕性能测试系统提供了可靠的数据和软件支持,提高了光幕性能测试系统的质量。     

视觉注意机制在图像增强中的应用研究

将视觉注意机制引入到直方图构造中,并在此基础上提出了一种新的基于灰度级信息量直方图的图像增强算法.该算法利用Itti视觉注意计算模型对图像的显著性进行分析,获得全局显著图;然后,将全局显著图划分为若干等大的子区域,求取各子区域的平均显著值,并做归一化处理,得到子区域的加权统计系数;再将各子区域的灰度级加权统计值相加,得到灰度级信息量直方图;最后,依据直方图均衡化的映射函数,调整灰度级的动态范围.实验结果表明,该算法明显优于经典的GHE算法和AHE算法,具有满意的视觉效果.     

《高等数学》CAI组件的研制

介绍了研制《高等数学》CAI组件的主导思想、主要内容及其特点,讨论了编程的主要技巧.     

A visual test paper for extremely strong concentrated acidity with a new synthesized isoindole reagent

A visual test paper by taking common filter paper as solid support for extremely strong concentrated acidity has been developed in this contribution with a new synthesized isoindole compound starting from p-phenylenediamine and the coupled fluorogenic reagent of o-phthaldialdehyde-β-mercaptoethanol. It was very easy for semiquantitative detection of acidity in the range of 0.2-18 M ([H⁺]) in extreme acidic solution based on the color changes of the solution or the visual test paper prepared by immerging filter paper slides into the solution of the new synthesized reagent. Quantitative detection of concentrated strong acids could be successfully constructed through the linear relationship exists between the absorbance of the chromogenic reagent at 510 nm and the acid concentrations.     

MODIS植被指数监测农业干旱的适宜性评价

MODIS传感器提供的短波红外光谱波段为农业干旱遥感监测带来了新的机遇,因为它对植被水分十分敏感。本文选择中国东北松嫩平原为研究区,旱田为农业干旱的监测目标。基于2001—2010年的8天合成MODIS产品（MOD09A1）,分别计算了四种基于可见光和近红外光谱的植被绿度指数和四种基于近红外和短波红外光谱的植被水分指数,并以多尺度标准化降水指标(SPI)为判别植被指数农业干旱敏感性的标准,利用一种气象站点与象元配对关联的方法计算了不同植被指数与多尺度SPI的皮尔逊相关系数。研究表明,在农业干旱监测敏感性方面,MODIS植被水分指数（NDII6和NDII7）明显好于植被绿度指数。其中NDII7的表现最为出色,研究证实了MODIS短波红外光谱在监测农业干旱方面的潜力,为今后相关研究提供了新的见解。