Genetic Deficiency and Pharmacological Stabilization of Mast Cells Ameliorate Pressure Overload-Induced Maladaptive Right Ventricular Remodeling in Mice

Although the response of the right ventricle (RV) to the increased afterload is an important determinant of the patient outcome, very little is known about the underlying mechanisms. Mast cells have been implicated in the pathogenesis of left ventricular maladaptive remodeling and failure. However, the role of mast cells in RV remodeling remains unexplored. We subjected mast cell-deficient WBB6F1-KitW/W-v (Kit^W/Kit^W-v) mice and their mast cell-sufficient littermate controls (MC^+/+) to pulmonary artery banding (PAB). PAB led to RV dilatation, extensive myocardial fibrosis, and RV dysfunction in MC^+/+ mice. In PAB Kit^W/Kit^W-v mice, RV remodeling was characterized by minimal RV chamber dilatation and preserved RV function. We further administered to C57Bl/6J mice either placebo or cromolyn treatment starting from day 1 or 7 days after PAB surgery to test whether mast cells stabilizing drugs can prevent or reverse maladaptive RV remodeling. Both preventive and therapeutic cromolyn applications significantly attenuated RV dilatation and improved RV function. Our study establishes a previously undescribed role of mast cells in pressure overload-induced adverse RV remodeling. Mast cells may thus represent an interesting target for the development of a new therapeutic approach directed specifically at the heart.     

Electrodeposition of polycrystalline ZnTe from simple and citrate-complexed acidic aqueous solutions

The cathodic electrodeposition of polycrystalline zinc telluride from aqueous acidic solutions of zinc sulphate and tellurite, under constant or pulsing voltage, is described. Various compositions of the bath were tested with respect to the Zn/Te precursor ratio, including addition of citrate buffer as a complexation agent. Metallic (Ni and Ti) and semiconductor (CdTe and CdSe) electrodes were used as cathode-substrates. The deposits were characterized by XRD, SEM-EDX and FTIR techniques. The formation of compact barrier layers of zinc blend, stoichiometric ZnTe or mixed (Zn,Cd)Te was attained. Pulse plating in a citrate-free bath and constant potential plating from a citrate bath were seen to have the most beneficial effect on the properties of the electrodeposits, as leading to improved microstructure of the ZnTe films, in terms of crystallinity and stoichiometry. Further, the employment of [1 1 1]-oriented CdTe or CdSe substrates featured an epitaxial growth of polycrystalline ZnTe films as well as an improved Zn/Te atomic ratio compared to the metallic substrates.     

Densification and phase transformation of Si3N4 in the presence of mechanically activated BaCO3–Al2O3–SiO2 mixture

Densification as well as the →β phase transformation of Si₃N₄ were monitored as a function of activation time of the BaCO₃–Al₂O₃–SiO₂ additive mixture. The composition of the ternary mixture corresponded to celsian (BaAl₂Si₂O₈—BAS). Previously, mechanically activated powder mixtures for various lengths of time were added to Si₃N₄ in the amount of 10–30%. Sintering was performed at 1650–1700°C in nitrogen atmosphere up to 8 h. The changes in densification degree, as well as phase composition, were followed as a function of heating time and the time of mechanical activation of the additive mixture. The results obtained showed that mechanical activation retarded densification in samples heated up to 1700°C. On the other hand, for the constant sintering time, →β transformation of Si₃N₄ was enhanced with increasing activation time, and the amount of additives.     

Imaging Fullerene C60 with Atomic Resolution Using a Scanning Tunnelling Microscope

C₆₀ was purified and imaged utilizing scanning tunnelling microscopy (STM) in a constant current mode. By fixing the Fullerenes on the substrate (“frozen state” - no movement or rotation), direct imaging of C₆₀ with atomic resolution was possible, showing one pentagon and one hexagon carbon ring of C₆₀.     

A pulse plating method for the electrosynthesis of ZnSe

Polycrystalline, thin films of ZnSe semiconductor compound were formed by cathodic electrodeposition from acidic aqueous selenite solutions of zinc sulphate, by using a potentiodynamic technique involving the application of repeated double pulses of controlled potential. Conditions for obtaining coherently uniform deposits with enhanced ZnSe to Se ratios were specified, on the basis of X-ray diffraction (XRD) and scanning electron microscopy results, by investigating the combined effect of the potential and length of each pulse as determined by duty cycle and frequency. It was shown that pulse plating process is a viable alternative to potentiostatic electrodeposition allowing improved control of the solid phase composition.     

Nanomagnetic behavior of fullerene thin films in Earth magnetic field in dark and under polarization light influences

In this paper magnetic fields intensity of C60 thin films of 60 nm and 100 nm thickness under the influence of polarization lights are presented. Two proton magnetometers were used for measurements. Significant change of magnetic field intensity in range from 2.5 nT to 12.3 nT is identified as a difference of dark and polarization lights of 60 nm and 100 nm thin films thickness, respectively. Specific power density of polarization light was 40 mW/cm2. Based on 200 measurement data average value of difference between magnetic intensity of C60 thin films, with 60 nm and 100 nm thickness, after influence of polarization light, were 3.9 nT and 9.9 nT respectively.     

RPATS – Reliable power aware time synchronization protocol

Many applications of Wireless Sensor Networks (WSNs) need the local clocks of the individual sensor nodes (SN) to be synchronized. Almost any form of sensor data fusion or coordinated actuation requires synchronized physical time for reasoning about events in the physical world. However, while the clock accuracy and precision requirements are often stricter in WSN than in traditional distributed systems, energy and channel constraints limit the resources available to meet these goals. In this paper, we present a power aware time synchronization protocol, of type sender–receiver, suitable for implementation in duty-cycled WSN. By using this proposal most of the non-deterministic time delays during packet transfer (media access, waiting packets in queues, propagation delay) as dominant ones (order of several hundred milliseconds), in respect to data processing (interrupt handling, testing status registers in program loop) as minor (up to hundred microseconds), are bypassed. In addition reliable and unreliable data transfer between SNs is considered. With aim to compensate SN’s oscillator instability, i.e. error in time synchronization, we propose duty cycle time extension. Apart from that, in order to evaluate the low-power capability of the proposed protocol we have involved quantitative performance metric called lifetime efficiency and compared it with equivalent (same) metric of the well known Reference-Broadcast Synchronization, RBS, and Timing-sync Protocol for Sensor Networks, TPSN, protocols, for different error prone environment and different period of time synchronization.     

Assessment of Essential and Toxic Mineral Elements in Bitter Gourd (Momordica Charantia) Fruit

In the United Arab Emirates (UAE), overall diabetes prevalence in adult population is around 20%. Along with, or instead of oral hypoglycemic drugs and insulin, some patients use bitter gourd (Momrodica charantia) because of its hypoglycemic properties. The aim of this study was to assess the essential (Ca, Mg, V, Cr, Mn, Co, Cu, Zn, and Mo) and toxic (As, Cd, Hg, and Pb) trace elements of bitter gourd using inductively coupled plasma-mass spectrometry (ICP-MS). Mean concentrations of each essential element were compared with literature data. Toxic As and Cd could not be detected, while Hg and Pb concentrations in our samples were much lower compared to values reported previously from contaminated areas. Results obtained in our study after ICP-MS/MW analysis, indicate that bitter gourd can be a good source of essential elements.