Dual material gate doping-less tunnel FET with hetero gate dielectric for enhancement of analog/RF performance

In this paper, charge-plasma-based tunnel FET is proposed by employing dual material gate with hetero gate dielectric technique and it is named hetero-dielectric dual material gate doping-less TFET(HD_DMG_DLTFET). It is compared with conventional doping-less TFET(DLTFET) and dual material gate doping-less TFET(DMG_DLTFET) on the basis of analog and RF performance. The HD_DMG_DLTFET provides better ON state current(I_ON=94 μA/μm), I_ON/I_OFF(≈ 1:36×10¹³), point(≈ 3 mV/dec) and average subthreshold slope(AV-SS=40.40 mV/dec). The proposed device offers low total gate capacitance(C_gg)along with higher drive current. However, with a better transconductance(g_m) and cut-off frequency(f_T), the HD_DMG_DLTFET can be a good candidate for RF circuitry. The early voltage(V_EA) and output conductance(g_d) are also moderate for the proposed device with comparison to other devices and therefore can be a candidate for analog devices. From all these simulation results and their study, it is observed that HD_DMG_DLTFET has improved analog/RF performance compared to DLTFET and DMG_DLTFET.     

Quantification of single-cell nanoparticle concentrations and the distribution of these concentrations in cell population

Quantification of nanoparticle uptake into cells is necessary for numerous applications in cellular imaging and therapy. Herein, synchrotron X-ray fluorescence (SXRF) microscopy, a promising tool to quantify elements in plant and animal cells, was employed to quantify and characterize the distribution of titanium dioxide (TiO₂) nanosphere uptake in a population of single cells. These results were compared with average nanoparticle concentrations per cell obtained by widely used inductively coupled plasma mass spectrometry (ICP-MS). The results show that nanoparticle concentrations per cell quantified by SXRF were of one to two orders of magnitude greater compared with ICP-MS. The SXRF results also indicate a Gaussian distribution of the nanoparticle concentration per cell. The results suggest that issues relevant to the field of single-cell analysis, the limitation of methods to determine physical parameters from large population averages leading to potentially misleading information and the lack of any information about the cellular heterogeneity are equally relevant for quantification of nanoparticles in cell populations.     

Optimization of process parameters for the production of Ni-Mn-Co-Fe based NTC chip thermistors through tape casting route

Ni-Mn-Co-Fe-O based ceramic compositions were prepared and their NTC thermistor characteristics were evaluated. The tape casting slurry composition was optimized to get defect free ceramic tapes. Chip thermistors were prepared from these NTC tapes by optimizing the process parameters. The prepared chip thermistors were tested for their thermal and electrical reliability and found to have excellent reliability. Tape casting can be employed as an effective and ideal method for the mass production of Ni-Mn-Co-Fe based miniaturized NTC chip thermistors.     

Direct observation of microbial adhesion to membranes

Direct microscopic observation and an interfacial force model were used to better understand and control microbial adhesion to polymeric ultrafiltration membranes. The model was used to predict a "critical flux", below which cells deposited reversibly, and direct observation was used to visually quantify cell deposition and removal. In preliminary direct observation experiments, permeate reversal (backpulsing) was more effective than cross-flow hydrodynamics at removing deposited cells. In experiments conducted below the critical flux, no cell accumulation was observed over repeated forward-reverse filtration cycles; however, a small fraction of cells deposited irreversibly regardless of the flux, membrane, or solution chemistry. The fraction of irreversibly deposited cells was consistent with the equilibrium surface coverage attained without permeation (i.e., due to heterogeneous adsorption). Although steric forces were not invoked to establish a critical flux, when operating above the critical flux, a balance between permeation drag and steric repulsion appeared to determine the strength of adhesion of cells to membranes. Direct observation also confirmed that above the critical flux fouling occurred and pressure losses accumulated over several backpulse cycles, whereas below the critical flux there were no observable pressure losses or fouling.     

Apoptosis Signal-Regulating Kinase 1 Is Involved in Brain-Derived Neurotrophic Factor (BDNF)-Enhanced Cell Motility and Matrix Metalloproteinase 1 Expression in Human Chondrosarcoma Cells

Chondrosarcoma is the primary malignancy of bone that is characterized by a potent capacity to invade locally and cause distant metastasis, and is therefore associated with poor prognoses. Chondrosarcoma further shows a predilection for metastasis to the lungs. The brain-derived neurotrophic factor (BDNF) is a small molecule in the neurotrophin family of growth factors that is associated with the disease status and outcome of cancers. However, the effect of BDNF on cell motility in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma cell lines had significantly higher cell motility and BDNF expression compared to normal chondrocytes. We also found that BDNF increased cell motility and expression of matrix metalloproteinase-1 (MMP-1) in human chondrosarcoma cells. BDNF-mediated cell motility and MMP-1 up-regulation were attenuated by Trk inhibitor (K252a), ASK1 inhibitor (thioredoxin), JNK inhibitor (SP600125), and p38 inhibitor (SB203580). Furthermore, BDNF also promoted Sp1 activation. Our results indicate that BDNF enhances the migration and invasion activity of chondrosarcoma cells by increasing MMP-1 expression through a signal transduction pathway that involves the TrkB receptor, ASK1, JNK/p38, and Sp1. BDNF thus represents a promising new target for treating chondrosarcoma metastasis.     

The C-Terminal Region of G72 Increases d-Amino Acid Oxidase Activity

The schizophrenia-related protein G72 plays a unique role in the regulation of d-amino acid oxidase (DAO) in great apes. Several psychiatric diseases, including schizophrenia and bipolar disorder, are linked to overexpression of DAO and G72. Whether G72 plays a positive or negative regulatory role in DAO activity, however, has been controversial. Exploring the molecular basis of the relationship between G72 and DAO is thus important to understand how G72 regulates DAO activity. We performed yeast two-hybrid experiments and determined enzymatic activity to identify potential sites in G72 involved in binding DAO. Our results demonstrate that residues 123–153 and 138–153 in the long isoform of G72 bind to DAO and enhance its activity by 22% and 32%, respectively. A docking exercise indicated that these G72 peptides can interact with loops in DAO that abut the entrance of the tunnel that substrate and cofactor must traverse to reach the active site. We propose that a unique gating mechanism underlies the ability of G72 to increase the activity of DAO. Because upregulation of DAO activity decreases d-serine levels, which may lead to psychiatric abnormalities, our results suggest a molecular mechanism involving interaction between DAO and the C-terminal region of G72 that can regulate N-methyl-d-aspartate receptor-mediated neurotransmission.     

DIANA: A computer-supported heterogeneous grouping system for teachers to conduct successful small learning groups

Teachers interested in small-group learning can benefit from using psychological factors to create heterogeneous groups. In this paper we describe a computer-supported grouping system named DIANA that uses genetic algorithms to achieve fairness, equity, flexibility, and easy implementation. Grouping was performed so as to avoid the creation of exceptionally weak groups. We tested DIANA with 66 undergraduate computer science students assigned to groups of three either randomly (10 groups) or using an algorithm reflecting [Sternberg, R. J. (1994). Thinking styles: theory and assessment at the interface between intelligence and personality. In R. J. Sterberg, & P. Ruzgis (Eds.), Personality and Intelligence (pp. 169–187). New York: Cambridge University Press.] three thinking styles (12 groups). The results indicate that: (a) the algorithm-determined groups were more capable of completing whatever they were “required to do” at a statistically significant level, (b) both groups were equally capable of solving approximately 80% of what they “chose to do,” and (c) the algorithm-determined groups had smaller inter-group variation in performance. Levels of satisfaction with fellow group member attitudes, the cooperative process, and group outcomes were also higher among members of the algorithm-determined groups. Suggestions for applying computer-supported group composition systems are offered.     

Numerical prediction of ion current from a small methane jet flame

This paper compares numerical simulations with experiments to describe the underlying mechanisms responsible for the voltage-current characteristic (VCC) response of a capillary-fed methane diffusion flame in an electric field. The numerical simulations, which include both combustion and electric phenomena, show good agreement with previously published experimental results, though computed flame temperatures were higher than those experimentally measured. Sub-saturated, saturated and super-saturated ion current regions are shown in the range of applied potentials: 0-2.5 kV, 2.5-3.4 kV and over 3.4 kV, respectively. The transition between the sub-saturated and saturated region is explored by predicting an evolution of the H₃O⁺ ion profile. Furthermore, the transition between the saturated and super-saturated current region is considered by following the rate of ion production. The simulations show an enhancement of ion production at high voltages suggesting that the main factor behind the increased ion production is the entrainment of air by the ion-driven wind into the fuel jet before the reaction zone, producing a partially premixed flame. Additionally, the change in chemical reaction pathways as a result of air entrainment is discussed.