A 3D Magnetic Hyaluronic Acid Hydrogel for Magnetomechanical Neuromodulation of Primary Dorsal Root Ganglion Neurons

Neuromodulation tools are useful to decipher and modulate neural circuitries implicated in functions and diseases. Existing electrical and chemical tools cannot offer specific neural modulation while optogenetics has limitations for deep tissue interfaces, which might be overcome by miniaturized optoelectronic devices in the future. Here, a 3D magnetic hyaluronic hydrogel is described that offers noninvasive neuromodulation via magnetomechanical stimulation of primary dorsal root ganglion (DRG) neurons. The hydrogel shares similar biochemical and biophysical properties as the extracellular matrix of spinal cord, facilitating healthy growth of functional neurites and expression of excitatory and inhibitory ion channels. By testing with different neurotoxins, and micropillar substrate deflections with electrophysical recordings, it is found that acute magnetomechanical stimulation induces calcium influx in DRG neurons primarily via endogenous, mechanosensitive TRPV4 and PIEZO2 channels. Next, capitalizing on the receptor adaptation characteristic of DRG neurons, chronic magnetomechanical stimulation is performed and found that it reduces the expression of PIEZO2 channels, which can be useful for modulating pain where mechanosensitive channels are typically overexpressed. A general strategy is thus offered for neuroscientists and material scientists to fabricate 3D magnetic biomaterials tailored to different types of excitable cells for remote magnetomechanical modulation.     

A Murine Oral‐Exposure Model for Nano‐ and Micro‐Particulates: Demonstrating Human Relevance with Food‐Grade Titanium Dioxide

Human exposure to persistent, nonbiological nanoparticles and microparticles via the oral route is continuous and large scale (10¹²–10¹³ particles per day per adult in Europe). Whether this matters or not is unknown but confirmed health risks with airborne particle exposure warns against complacency. Murine models of oral exposure will help to identify risk but, to date, lack validation or relevance to humans. This work addresses that gap. It reports i) on a murine diet, modified with differing concentrations of the common dietary particle, food grade titanium dioxide (fgTiO₂), an additive of polydisperse form that contains micro‐ and nano‐particles, ii) that these diets deliver particles to basal cells of intestinal lymphoid follicles, exactly as is reported as a “normal occurrence” in humans, iii) that confocal reflectance microscopy is the method of analytical choice to determine this, and iv) that food intake, weight gain, and Peyer's patch immune cell profiles, up to 18 weeks of feeding, do not differ between fgTiO₂‐fed groups or controls. These findings afford a human‐relevant and validated oral dosing protocol for fgTiO₂ risk assessment as well as provide a generalized platform for application to oral exposure studies with nano‐ and micro‐particles.     

Hybridization of stochastic reduced basis methods with polynomial chaos expansions

We propose a hybrid formulation combining stochastic reduced basis methods with polynomial chaos expansions for solving linear random algebraic equations arising from discretization of stochastic partial differential equations. Our objective is to generalize stochastic reduced basis projection schemes to non-Gaussian uncertainty models and simplify the implementation of higher-order approximations. We employ basis vectors spanning the preconditioned stochastic Krylov subspace to represent the solution process. In the present formulation, the polynomial chaos decomposition technique is used to represent the stochastic basis vectors in terms of multidimensional Hermite polynomials. The Galerkin projection scheme is then employed to compute the undetermined coefficients in the reduced basis approximation. We present numerical studies on a linear structural problem where the Youngs modulus is represented using Gaussian as well as lognormal models to illustrate the performance of the hybrid stochastic reduced basis projection scheme. Comparison studies with the spectral stochastic finite element method suggest that the proposed hybrid formulation gives results of comparable accuracy at a lower computational cost.     

在路上：柯达DPS分析日

2009年7月20～21日，柯达在其美国的代顿工厂迎来了DPS（数字印刷解决方案）分析日。本刊专栏作者Andy和Julie亲临现场，为我们发来精彩报道，深入解读柯达的未来发展。     

The reading grade level of common measures in child and adolescent clinical psychology.

The purpose of this article is to provide easily accessible readability information for 49 parent- and 35 child- and adolescent-report measures commonly used by clinicians and researchers. There is a great deal of variability in reading ability required across measures. The majority of parent-report measures (65%) required reading ability above the 8th grade level. The average child-/adolescent-report measure required reading ability above the 6th grade level. Given the potential contribution of readability to a measure's reliability, validity, and overall utility, examining and accounting for readability should be a more common practice in test construction and administration (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving Quality of Crane-Lorry Assignments With Constraint Programming

The ability to maximize service quality while minimizing cost is very important to service-oriented businesses, such as lorry leasing. Very often, the ability to consistently offer higher quality service is the main differentiating factor between a business and its competitors. For lorry leasing businesses, service quality and cost are directly related to how resources-vehicles, cranes, and drivers-are allocated to jobs. The ability to assign the right combination of resources is crucial to daily operations. This paper presents how we modeled this assignment problem as a constraint-satisfaction problem (CSP) and implemented using constraint programming (CP) with an algorithm that we call the crane-lorry optimizing engine (CLOE). CLOE was implemented for the largest crane-lorry company in Hong Kong. Furthermore, plans are generated within seconds compared to close to an hour if done manually. All necessary constraints and criteria are considered systematically. We have experimented with many different types of search heuristics and have analyzed their effects on plan quality. We have found that by considering both the experience of the crane-lorry-driver combination and maximizing on the order assignment, we were able to generate plans that were significantly better than those produced by human planners, and within a substantially shorter time. Although the use of constraint-based assignment techniques is still limited in the vehicle leasing industry, we hope our combination of automated assignment with Internet portal technology that streamlines business-to-business, business-to-consumer, and business-to-employee communications can excite interest in this area     

以更好的仪器协调提高测试处理能力

对于所有电子元件来说,测试速度都非常重要,尤其对于低价的两端或三端器件,如二极管和晶体管测试速度更是至关重要.例如,大多数类型的二极管在最终的检测中都要测试至少三个基本直流参数:正向电压(VF)、击穿电压(VR)和漏泄电流(IR).这些测试必须要求快速精确.     

防止电池充电器控制信号丢失的看门狗电路

为手机内部电池充电一般受到专有充电算法的控制，这种算法是保存在基带控制器中的。充电器通过一个低导通电阻的P沟道MOSFET开关连接到内部电池上（图1）。基带控制器产生一个PWM信号驱动开关。为减少话机的功耗以及随之而来的散热问题，充电电源（通常是一个插入式变压器套件）有内部限流功能，其规格对应于电池的化学特性以及充电恢复需求。