Single crystal field-effect transistors based on an organic selenium-containing semiconductor

We report on the fabrication and characterization of single crystal field-effect transistors (FETs) based on diphenylbenzo diselenophene (DPh-BDSe). These organic field-effect transistors (OFETs) function as p-channel accumulation-mode devices. At room temperature, for the best devices, the threshold voltage is less than -7V and charge carrier mobility is nearly gate bias independent, ranging from 1cm2/Vs to 1.5 cm2/Vs depending on the source-drain bias. Mobility is increased slightly by cooling below room temperature and decreases below 280 K

Fluid Devices by the Use of Electrohydrodynamic Effects of Water

When the high DC electric fields are applied to distilled water through needle electrodes, the jet flow with velocities up to 0.3 ms-1 is generated in bulk from the negative to positive electrodes. The flow direction and velocity can be modified by the design of electrodes and their arrangements. By controlling the flow patterns, new types of inkjet devices and liquid motor are developed. In inkjet devices, a set of electrodes consisting of short tube and needle is vertically placed in plastic tube and the distilled water so filled in the reservoir that the electrodes are completely immersed. The application of high voltages causes the vertical flow to produce a water column with free surface. The motor consists of vane wheel, cup, two sets of electrodes, and working fluid. For aqueous solutions of ethanol and glycerin, the angular velocity of motor is measured as a function of viscosity and conductivity. The high performance of motor is achieved by the solutions with viscosity of 0.85 ~ 1.7 m Pa·s and conductivity of 20 ~ 30 Sm-1. The EHD water jets have great potential in application to new fluid devices

Influence of synaptic depression on memory storage capacity

Synaptic efficacy between neurons is known to change within a short time scale dynamically. Neurophysiological experiments show that high-frequency presynaptic inputs decrease synaptic efficacy between neurons. This phenomenon is called synaptic depression, a short term synaptic plasticity. Many researchers have investigated how the synaptic depression affects the memory storage capacity. However, the noise has not been taken into consideration in their analysis. By introducing "temperature", which controls the level of the noise, into an update rule of neurons, we investigate the effects of synaptic depression on the memory storage capacity in the presence of the noise. We analytically compute the storage capacity by using a statistical mechanics technique called Self Consistent Signal to Noise Analysis (SCSNA). We find that the synaptic depression decreases the storage capacity in the case of finite temperature in contrast to the case of the low temperature limit, where the storage capacity does not change

Computational modelling of meiotic entry and commitment

In response to developmental and environmental conditions, cells exit the mitotic cell cycle and enter the meiosis program to generate haploid gametes from diploid germ cells. Once cells decide to enter the meiosis program they become irreversibly committed to the completion of meiosis irrespective of the presence of cue signals. How meiotic entry and commitment occur due to the dynamics of the regulatory network is not well understood. Therefore, we constructed a mathematical model of the regulatory network that controls the transition from mitosis to meiosis in Schizosaccharomyces pombe. Upon nitrogen starvation, yeast cells exit mitosis and undergo conjugation and meiotic entry. The model includes the regulation of Mei2, an RNA binding protein required for conjugation and meiotic entry, by multiple feedback loops involving Pat1, a kinase that keeps cells in mitosis, and Ste11, a transcription activator required for the sexual differentiation. The model accounts for various experimental observations and demonstrates that the activation of Mei2 is bistable, which ensures the irreversible commitment to meiosis. Further, we show by integrating the meiosis-specific regulation with a cell cycle model, the dynamics of cell cycle exit, G1 arrest and entry into meiosis under nitrogen starvation. © 2017 The Author(s)

Mass spectrometry imaging identifies palmitoylcarnitine as an immunological mediator during Salmonella Typhimurium infection

Salmonella Typhimurium causes a self-limiting gastroenteritis that may lead to systemic disease. Bacteria invade the small intestine, crossing the intestinal epithelium from where they are transported to the mesenteric lymph nodes (MLNs) within migrating immune cells. MLNs are an important site at which the innate and adaptive immune responses converge but their architecture and function is severely disrupted during S. Typhimurium infection. To further understand host-pathogen interactions at this site, we used mass spectrometry imaging (MSI) to analyse MLN tissue from a murine model of S. Typhimurium infection. A molecule, identified as palmitoylcarnitine (PalC), was of particular interest due to its high abundance at loci of S. Typhimurium infection and MLN disruption. High levels of PalC localised to sites within the MLNs where B and T cells were absent and where the perimeter of CD169+ sub capsular sinus macrophages was disrupted. MLN cells cultured ex vivo and treated with PalC had reduced CD4+CD25+ T cells and an increased number of B220+CD19+ B cells. The reduction in CD4+CD25+ T cells was likely due to apoptosis driven by increased caspase-3/7 activity. These data indicate that PalC significantly alters the host response in the MLNs, acting as a decisive factor in infection outcome

Improvement in current efficiency of electroplated Fe-Ni films prepared in citric-acid-based baths

Fe-Ni films were electroplated in a citric-acid-based plating bath, focusing on the current efficiency of the plating process. We prepared the plating baths with various citric acid contents, and evaluated the magnetic properties of the films and the current efficiency. The film with Fe content of approximately 22 at.?% was obtained by adjusting the iron sulfate content in the plating bath, and we found that the Fe-Ni films with low coercivity (<30?A/m) could be obtained in the baths with various citric acid contents. For the current efficiency, we found that the baths with low citric acid content are effective to obtain high efficiency. The bath with the citric acid content of 10?g/l showed high current efficiency (85%), and the high efficiency enables us to increase the plating rate. The maximum plating rate was 186?μm/h, and we obtained 1.3 times higher rate compared to that for our previous study. Therefore, we concluded that the bath with low citric acid content is a suitable plating bath to obtain thick Fe-Ni films in a short time