Strength of synaptic transmission at neuromuscular junctions of crustaceans and insects in relation to calcium entry

Crustacean and insect neuromuscular junctions typically include numerous small synapses, each of which usually contains one or more active zones, which possess voltage-sensitive calcium channels and are specialized for release of synaptic vesicles. Strength of transmission (the number of quantal units released per synapse by a nerve impulse) varies greatly among different endings of individual neurons, and from one neuron to another. Ultrastructural features of synapses account for some of the physiological differences at endings of individual neurons. The nerve terminals that release more neurotransmitter per impulse have a higher incidence of synapses with more than one active zone, and this is correlated with more calcium build-up during stimulation. However, comparison of synaptic structure in neurons with different physiological phenotypes indicates no major differences in structure that could account for their different levels of neurotransmitter release per impulse, and release per synapse differs among neurons despite similar calcium build-up in their terminals during stimulation. The evidence indicates differences in calcium sensitivity of the release process among neurons as an aspect of physiological specialization.     

Evaluation of realtime people tracking for indoor environments using ubiquitous motion sensors and limited wireless network infrastructure

We present the development and evaluation of a realtime indoor localisation system for tracking people. Our aim was to track a person’s indoor position using dead-reckoning, while limiting position error without depending on extensive wireless network infrastructure. The Indoor People Tracker used wearable motion sensors, a floor-plan map and a limited wireless sensor network for proximity ranging. We evaluated how the position accuracy of the Indoor People Tracker was affected by floor-plan map features, wireless proximity range and motion information. The advantage of the Indoor People Tracker was found; it was able to achieve accurate position resolution with minimal error, while not depending on wireless proximity.     

Adsorption of Chrysoidine R by using fly ash in batch process

This investigation deals with effective utilization of fly ash as adsorbent for the removal of Chrysoidine R from the aqueous solution. The fly ash is a major byproduct generated in coal-based thermal power plants and has good potential for use as an adsorbent. A series of experiments were carried out in a batch adsorption technique to obtain the effect of process variables viz. contact time, pH (2, 4, 6 and 8) initial concentration of the dye (400, 600, 800 and 1000mgL(-1)), amount of the adsorbent (125, 250, 375 and 500mgL(-1)), and temperature (303, 313, 323 and 333K) on adsorption. The concentration of dye was determined by spectrophotometer. The results showed that as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly; higher adsorption percentage was observed at lower concentration of chrysoidine. The adsorption data were analyzed using Langmuir and Freundlich isotherms. The adsorption was found to obey pseudo-first order kinetics. An intra particle diffusion model was used to fit the experimental data. The thermodynamic parameters such as standard change in free energy, enthalpy and entropy of adsorption have been calculated. Adsorption of Chrysoidine R on fly ash was found to be an exothermic reaction.     

Improved gas holdup in novel bubble column

This investigation reports the experimental and theoretical results carried out to evaluate the gas holdup for air–water system in a novel hybrid rotating and reciprocating perforated plate bubble column under countercurrent condition. The response of this hybrid column is found to be similar to that of reciprocating plate column (RPC) showing mixer‐settler, transition, and emulsion regions. The effect of agitation level, superficial gas velocity, superficial liquid velocity, perforation diameter, and plate spacing on gas holdup is studied and found to be significant. The gas holdup is found to be least in the range of agitation level of 1.3–1.5 cm/s. For all the superficial gas and liquid velocities considered in this present investigation, the critical agitation level at minimum gas holdup remains nearly same. The gas holdup in this hybrid column is 1.2–1.7 times higher in mixer‐settler region and 2.1–2.7 times higher in emulsion region than that of RPC. Correlations have been developed and found to concur with the experimental values. It can be used with 95% accuracy. © 2011 Canadian Society for Chemical Engineering     

Computer‐aided design of tailor‐made ionic liquids

Ionic liquids (IL), with their negligible vapor pressure, have the potential to replace volatile organic solvents in several processes. They also exhibit other unique characteristics, such as high thermal stability, wide liquid range, and wide electrochemical window, which make them attractive for many important applications. In addition, millions of ILs can be formed through different combination of cations, anions, and other functional groups. Till now, majority of work on IL selection, for a given application, is guided by trial and error experimentation. In this article, we present a computer‐aided IL design framework, based on semiempirical structure‐property models and optimization methods, which can consider several IL candidates and design optimal structures for a given application. This powerful methodology has great potential to act as a knowledge‐based framework to aid synthetic chemists and engineers develop new ILs. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4627–4640, 2013     

Statistical analysis of effects of experimental variables on mass transfer coefficient in a novel hybrid bubble column using Box–Behnken design

Statistical analysis of effects of experimental variables on volumetric mass transfer coefficient in a novel hybrid rotating and reciprocating perforated plate bubble column is studied. The novel bubble column is designed indigenously using bevel gear arrangement. Agitation level, superficial gas velocity, superficial liquid velocity, perforation diameter and plate spacing are the experimental variables. Air–sodium sulphite solution system is used in this investigation. The Box–Behnken design in response surface methodology is employed for statistical analysis. The relationship between experimental variables and the desired response of volumetric mass transfer coefficient is established for this novel hybrid column. The linear, quadratic and interactive effects of experimental variables are found to be significant on the desired response of volumetric mass transfer coefficient. Results show that the data adequately fit into the second‐order polynomial model. An F‐test and P‐value show the significance of parameters on volumetric mass transfer coefficient. © 2012 Canadian Society for Chemical Engineering     

Paramagnetic Quantum Dots as Multimodal Probes for Potential Applications in Nervous System Imaging

An axonal tracer that can be detected by both magnetic resonance imaging (MRI) and fluorescence is of great interest for studying nerve regeneration, particularly for spinal cord injury repairs. In this study, we develop a new type of multifunctional nanoparticle that combines three different functionalities of paramagnetism, fluorescence, and axonal tracing into one nanomaterial. We demonstrate that the new synthesized quantum dot nanoparticles have good biocompatibilities and can be readily taken up by cells. In addition, the quantum dots show excellent longitudinal and transverse relaxivities (i.e. r ₁ ?=?11.22?±?0.10 mM^?1 s^?1 and r ₂ ?=?24.50?±?0.51 mM^?1 s^?1) at 1.5 T, MRI contrast properties better than those of Magnevist®, a commercially available MRI contrast agent. The UV–vis absorbance spectra of all the pQDs-BDA samples indicate that these tracers are stable at different temperatures. Taken together, this new nanomaterial demonstrates good performances for both optical and MR imaging modalities, suggesting its promising potential applications in non-invasive imaging, particularly as a novel multimodal axonal tracer for nervous system imaging.     

Internetworking framework in underwater wireless sensor network protocol to a certain connectivity using probabilistic approaches

Microsystem Technologies - Ocean acidification is one of the parameters that affect underwater wireless sensor network routing protocols. The underlying network-level metrics of sensor nodes...     

通过模型为基础的溶液选择来调控药品化合物的形貌

In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the formulation of the property constraint for crystal morphology. This involves crystallization experiments and development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming model. The design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals (precipitated from the designed solvent) is verified through crystallization experiments followed by productcharacterization via scanning electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.