+Gz acceleration affects the trace minerals zinc, copper, and chromium in serum and urine of humans

BACKGROUND: Research investigating the relationship between physical training and trace mineral concentrations has primarily focused on athletes. Few investigations, however, have specifically examined the alterations of trace mineral concentrations occurring in humans exposed to +Gz acceleration. Exercise alters mineral content; G-exposure is a form of exercise; therefore, G-exposure may elicit changes in mineral content. HYPOTHESIS: Exposure to +Gz acceleration may affect the concentrations of the trace minerals zinc, copper, and chromium in human serum and urine. METHODS: Blood samples were obtained from 7 men and 3 women, before and immediately after +Gz acceleration. Urine samples were obtained before, 30 min after, and 2 h after +Gz acceleration. RESULTS: The serum zinc concentration was significantly different after +Gz acceleration, decreasing from 90.6 +/- 21.0 micrograms.dl-1 to 80.8 +/- 14.4 micrograms.dl-1. The serum copper concentration was also significantly altered immediately after +Gz acceleration, decreasing from 111.7 +/- 27.5 micrograms.dl-1 to 98.5 +/- 35.2 micrograms.dl-1. The urinary zinc and copper concentrations, and the serum chromium concentration were not significantly affected by +Gz acceleration. CONCLUSIONS: The circulating levels of these minerals presumably change as they are transported to the tissues requiring greater amounts due to the increased physiological work associated with +Gz acceleration.     

Cardiac surgery using cardiopulmonary bypass in a patient with sickle-cell trait

The sickle-cell gene is most concentrated in West Central Africa, the northeast corner of Saudi Arabia and East Central India. Sickle cell trait is the heterozygous condition for Hb S gene. Thirty to fifty per cent of their hemoglobin is Hb S and the remainder is Hb A. The sickle-cell crisis is induced by hypoxia, hypercarbia, acidosis, low flow condition, and hypothermia, which leads to vasoocclusion. A 39-year-old black man from Burkina Faso located in West Africa with left ventricular rupture was admitted for operation using cardiopulmonary bypass (CPB). He had been diagnosed as sickle-cell trait. The Hb S concentration was 36.2 per cent before operation with hemoglobin electrophoresis. During CPB, the minimum blood temperature was 31 degrees C and an aortic cross-clamp was not done. Total CPB time was 1 hour 31 minutes. Use of vasodilator and hyperventilation was effective. No neurological sequelae were observed.     

Characterization of chromatic dispersion of optical filters by high-stability real-time spectral interferometry

Chromatic dispersion of optical filters is characterized by what is believed to be novel broadband spectral interferometry, which is based on dual-wavelength heterodyne measurement of spectral phase. High phase stability is achieved by differential phase detection using two lasers for wavelength-swept probe and phase-tracking reference. The technique provides self-tracking interferometry by passive stabilization of optical phase and allows real-time measurement of spectral phase and group delay with a low phase drift of less than 0.04pi. A fiber Bragg grating and a thin-film filter are characterized by this method.     

Characterization of chitosan/citrate and chitosan/acetate films and applications for wound healing

In this work, we aimed to develop a scaffold of chitosan (CS) with a porous sponge structure for an artificial skin. The scaffolds were prepared from both CS/citric and CS/acetic solutions. In addition, the cast films were also prepared from the same solutions to compare some of their properties. They were characterized using WAXD, FTIR, DSC, tensile measurements, and SEM observation. It was found that CS/acetate had low crystallinity but CS/citrate was in an amorphous state, resulting in a large ductility with rubbery softness. Despite the different morphologies of CS/citrate and CS/acetate scaffolds, both scaffolds exhibited the wound healing effect available for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Controlled self-assembly of metal-organic frameworks on metal nanoparticles for efficient synthesis of hybrid nanostructures

We report a novel approach for synthesizing inorganic nanoparticle/metal-organic frameworks (MOFs) heterostructured nanocomposites by self-assembly of MOFs on nanoparticles. This approach involves the synthesis of Au nanoparticles and preferential growth of [Cu(3)(btc)(2)](n) frameworks consisting of Cu(2+) ions and benzene-1,3,5-tricarboxylate (btc) on nanoparticles. Aggregates consisting of 11-mercaptoundecanoic acid (MUA)-stabilized Au nanoparticles linked by Cu(2+) ions were necessary for preferential self-assembly of [Cu(3)(btc)(2)](n) frameworks on the aggregates, resulting in the formation of Au nanoparticles/[Cu(3)(btc)(2)](n) nanocomposites. The present approach was confirmed to be applicable for other hybrids consisting of Au nanoparticles and tetragonal [Cu(2)(ndc)(2)(dabco)](n) frameworks.     

Analysis of exciton annihilation in high-efficiency sky-blue organic light-emitting diodes with thermally activated delayed fluorescence

We study external quantum efficiency (η_EQE) roll-off in organic light-emitting diodes (OLEDs) using thermally-activated delayed fluorescence (TADF) of 4,5-di (9H-carbazol-9-yl) phthalonitrile (2CzPN). Using 2CzPN intramolecular rate constants from optical analyses, we construct an exciton quenching model incorporating intersystem crossing and reverse intersystem crossing. The model indicates that singlet–triplet annihilation and triplet–triplet annihilation dominate η_EQE roll-off because of the relatively long 2CzPN triplet lifetime of 273 μs. This work yields a method to relax the exciton quenching process in TADF based OLEDs.     

Characterization by Stm and Electrical Conductivity of Single-Walled Carbon Nanotubes

Abstract

Single-walled carbon nanotubes (SWCNT) prepared by a DC-Arc-Discharge and purified by a hydrothermal treatment followed by several steps of procedures including heating, burning, extracting and acid-washing are investigated by a conventional STM technique morphologically and spectroscopically. The electical resistivities of compacted pellets (mats) of SWCNT are measured as a function of temperature in the range from the room-temperature to 1.5K. The behaviors seems to be essentially originated in the metallic nature of individual SWCNT.     

Lamellar eutectic growth with anisotropic interphase boundaries: Experimental study using the rotating directional solidification method

We report on an experimental study of the effects of interphase boundary anisotropy on eutectic microstructures using a new methodology called rotating directional solidification (RDS), which consists of rotating a thin sample with respect to a fixed unidirectional thermal gradient. The systems used are thin, large eutectic grains of the CBr₄–C₂Cl₆ and In–In₂Bi lamellar eutectic alloys. The shape of the observed RDS lamellar trajectories turns out to be a reproducible eutectic-grain-dependent feature, in agreement with the theoretical prediction that these trajectories are approximately homothetic to the Wulff form of the interphase boundary in the sample plane. We show that different modes of lamellar growth, ranging from quasi-isotropic to (crystallographically) locked, exist in different eutectic grains of the two alloys studied. A detailed characterisation of these modes is given, with particular attention to the as-yet poorly understood aspects of locked lamellar growth.     

Polypropylene plasticization and photodegradation with a TiO2/poly(ethylene oxide)/methyl linoleate paint photocatalyst system

The photodegradation of polypropylene (PP) film was performed by a TiO₂/polyethylene oxide (PEO)/plant oil paint photocatalyst system. The photodegradation underwent two stages of development as follows: Initially PP reacted with linoleic acid radical originated from the photoreaction of plant oil component. Second, the linoleic acid graft‐polymer was decomposed, and then PP chain scission was caused. The process was studied using methyl linoleate (ML) in detail. The melting point of the 24 h‐photodegraded PP slightly decreased, and those of the 48 h‐ and 96 h‐ones drastically did as compared with the pristine PP. The crystallinity (χ_c) decreased at the 48 h photodegradation time and drastically increased at the 96 h one. The 24 h‐photodegraded PP showed the 77% Young's modulus, 88% tensile strength, and 103% strain at break values to those of the pristine PP. The ML graft‐polymerization and decomposition brought about the PP plasticizing and chemi‐crystallization, causing the PP degradation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39909.