Colorimetric Detection of Hg2+ Based on the Growth of Aptamer‐Coated AuNPs: The Effect of Prolonging Aptamer Strands

Herein, a versatile and sensitive colorimetric sensor for Hg²⁺ based on aptamer–target specific binding and target‐mediated growth of AuNPs is reported. The 15 T bases are first designed to detect Hg²⁺ through T–Hg²⁺–T coordination. Aptamer–target binding results in the desorption of the aptamer from AuNP surface, the remaining aptamers adsorbed on AuNP surface trigger the growth of AuNPs with morphologically varied nanostructures, and then different colored solutions are formed. On this occasion, the limit of detection (LOD) of 9.6 × 10^?9m is obtained. The other two aptamer strands (25‐ and 59‐mer) are designed by increasing A bases on either side and both sides of 15 T, respectively. The interaction of the binding domain and Hg²⁺ makes desorption of 15 T from AuNP surface, whereas excess bases not committed to the binding domain still adsorbed on AuNP surface. These excess bases control the growth of AuNPs, and enhance the sensitivity. The LODs are 4.05 and 3 × 10^?9m for 25‐ and 59‐mer aptamers, respectively. In addition, the 59‐mer aptamer system is applied to identify Hg²⁺ in real river samples, the LOD of 6.2 × 10^?9m is obtained.     

Tensile strength,peel load,and static puncture resistance of laminated composites reinforced with nonwoven fabric

Nonwoven fabrics were used as reinforcement to laminated composites to improve the mechanical properties and damage behaviors. The needle-punched Kevlar/LMPET nonwoven interlayer and two TPU covers were combined via thermal bonding to form the laminated composites. Tensile strength, peel load, and static puncture resistance of the laminated composites were evaluated in terms of needle punching rate and depth of the nonwoven interlayer. Results showed that tensile strength and static puncture resistance depended on the needle punching depth, primarily on the tangled fiber points. The peel load was dependent on the needle punching rate, especially on the resulting melted LMPET fibers. The laminated composites exhibited desirable tensile properties, peel load, and static puncture resistance.     

Pharmacokinetic properties and bioequivalence of orally inhaled salbutamol in healthy Chinese volunteers

Context: Salbutamol is a short-acting β₂-adrenergic receptor agonist that has been used for many years for relief of bronchospasm. However, studies on the pharmacokinetic profile of orally inhaled salbutamol doses used in clinical practice have not yet been reported in Chinese subjects.

Objective: The aim of this study was to compare the pharmacokinetics and evaluate the bioequivalence of two orally inhaled salbutamol formulations.

Materials and methods: A single-dose randomized fasting two-period, two-treatment and two-sequence crossover open-label bioequivalence study was conducted in 24 healthy Chinese adult male volunteers, with a 1-week washout period between treatments. Plasma concentrations of salbutamol were determined using liquid chromatography coupled to tandem mass spectrometry. Pharmacokinetic parameters, including AUC_0–0.33?h, AUC_0–24?h and C_max were calculated and the 90% confidence intervals of the ratio (test/reference) pharmacokinetic parameters were obtained by analysis of variance on logarithmically transformed data.

Results: The mean (SD) pharmacokinetic parameters of the reference drug were AUC_0–0.33?h, 227.2 (89.9) pg·h/ml; AUC_0–24?h, 2551.9 (1008.0) pg·h/ml; C_max, 801.3 (307.3) pg/ml and t_1/2, 5.14(1.36) h. Those of the test drug were AUC_0–0.33?h, 244.0 (104.4) pg·h/ml; AUC_0–24?h, 2664.4 (1081.8) pg·h/ml; C_max, 873.7 (374.4) pg/ml, t_1/2, 5.29 (1.23) h. The median value for T_max was 0.25?h for both formulations. The 90% confidence intervals for the AUC_0–0.33?h, AUC_0–24?h and C_max were in the range of 0.892–1.208, 0.876–1.195 and 0.911–1.203, respectively.

Conclusion: This single-dose study found that the test and reference products met the regulatory criteria for bioequivalence of China in healthy Chinese volunteers.     

Locality sensitive hashing with bit selection

Applied Intelligence - Locality sensitive hashing (LSH), one of the most popular hashing techniques, has attracted considerable attention for nearest neighbor search in the field of image...     

Distributed consensus estimation for diffusion systems with missing measurements over sensor networks

In this paper, the problem of distributed consensus estimation with randomly missing measurements is investigated for a diffusion system over the sensor network. A random variable, the probability of which is known a priori, is used to model the randomly missing phenomena for each sensor. The aim of the addressed estimation problem is to design distributed consensus estimators depending on the neighbouring information such that, for all random measurement missing, the estimation error systems are guaranteed to be globally asymptotically stable in the mean square. By using Lyapunov functional method and the stochastic analysis approach, the sufficient conditions are derived for the convergence of the estimation error systems. Finally, a numerical example is given to demonstrate the effectiveness of the proposed distributed consensus estimator design scheme.     

融合局部思想和协作表达的鲁棒分类

目的 协作表达分类算法在人脸识别实验上表现出较好的性能,但其未考虑样本的局部特性,且算法只能处理测试样本中的噪声,未能有效处理训练样本集中的噪声.针对这两个问题,提出融合局部思想和协作表达的鲁棒分类算法.方法 一方面,在训练集上,通过奇异值分解SVD得到其有效表达,丢弃一些噪声;另一方面,算法考虑数据的局部相似性,以保持测试样本与其相邻训练样本之间的相似性.结果 本文算法能得到一个闭式(closed-form),可避免稀疏表示分类算法中由于迭代引起的高时间复杂度问题,在ORL、扩展YALEB和PIE人脸库上的识别率分别可达91.4%,93.8%和93.2%,与同类算法相比识别率有较大幅度地提高;实验结果验证了算法所得到的系数具有较高的判别能力.结论 算法将训练样本进行奇异值分解得到“干净”的训练样本,能在一定程度上消除噪声的影响,且在协作表达的基础上,考虑测试样本和与之相邻的训练样本的局部相似性,相比原始的协作表达分类算法有更好的稳定性和鲁棒性.     

弹丸任意角度入射弹着点声学检测模型

声学靶被广泛应用于弹着点自动检测系统中,常规声学立靶测量系统要求弹丸垂直靶面入射,否则弹着点测量精度较低.基于声学定位技术,分析弹丸沿任意角度入射过程,根据弹着点和传感器阵列之间的几何关系,利用传感器阵列接收激波的时间差,建立一种针对弹丸任意角度入射的弹着点检测数学模型.应用上述数学模型对立体七点布阵的传感器阵列进行仿真研究,仿真结果表明立体阵列模型在整个靶平面的弹着点误差均值为0.8821 cm,标准差为0.6104 cm.实弹射击实验表明基于七点立体阵列的弹丸任意角度入射弹着点声学检测模型具有较高的精度.