Characterization of Starch from Maize Endosperm Mutants

Some maize endosperm mutants have branched-chain starch components with long exterior chains which make the blue-value procedure for estimating amylose content questionable. Gel filtration was used to estimate starch composition of normal, high-amylose, waxy and other maize endosperm mutants. Loosely-branched polymers appeared responsible for the apparent amylose content. In some mutants high and intermediate loosely branched polysaccharides were found in addition to amylose. The sweet corn background of some endosperm genotypes influenced the types of polymers produced compared to the dent backgrounds used by previous researchers.     

Pathogenesis and Treatment of Myeloma-Related Bone Disease

Multiple myeloma is a hematologic malignancy of plasma cells that causes bone-destructive lesions and associated skeletal-related events (SREs). The pathogenesis of myeloma-related bone disease (MBD) is the imbalance of the bone-remodeling process, which results from osteoclast activation, osteoblast suppression, and the immunosuppressed bone marrow microenvironment. Many important signaling cascades, including the RANKL/RANK/OPG axis, Notch signaling, the Wnt/β-Catenin signaling pathways, and signaling molecules, such as DKK-1, sclerostin, osteopontin, activin A, chemokines, and interleukins are involved and play critical roles in MBD. Currently, bisphosphonate and denosumab are the gold standard for MBD prevention and treatment. As the molecular mechanisms of MBD become increasingly well understood, novel agents are being thoroughly explored in both preclinical and clinical settings. Herein, we will provide an updated overview of the pathogenesis of MBD, summarize the clinical management and guidelines, and discuss novel bone-modifying therapies for further management of MBD.     

Corrosion behavior of pure tin deposit under 55 °C/85 % RH reliability test

With recent moves to implement lead-free manufacturing in the electronics industry, more attention is being paid to the use of tin. One of greatest limitations regarding the reliability of tin is the undesirable development of tin whiskers. Many factors have been identified as being the cause of these whiskers, though tin corrosion has not. Three types of tin deposit grain structures have been developed in an effort to reduce the growth of whisker formations as type (A) with vertical and regular grain boundary; type (B) with horizontal and irregular grain boundary; and type (C) as a combination of both vertical (the top layer) and horizontal (the bottom layer) grain structures. We kept a series of samples in an oven for 1 year at 55 °C/85 % RH (relative humidity), and then used focused ion beam to examine the corrosion microstructure that occurred three types of deposit structures. We found the preferred path of corrosion to occur along the grain boundary and that tin oxide enlarges the volume of the deposit. In order to release the compressive stress that developed during corrosion, whiskers were formed as the grain structure being vertical. Corrosion developed in different locations of various deposits made of the three grain structures. We studied resulting in whisker growth, cracking and the development of internal oxide.     

Promotion of the electrocatalytic activity of a bimetallic platinum-ruthenium catalyst by repetitive redox treatments for direct methanol fuel cell

Pt-Ru/C catalyst (12 wt%) was prepared by the incipient wetness impregnation method followed by a redox heat-treatment. Transmission electron microscopy (TEM) results revealed uniformly distributed metallic crystallites of Pt-Ru alloy nanoparticles (d_PtRu = 2.1 ± 1.0 nm). The effect of redox treatments of the impregnated catalysts on methanol oxidation reaction (MOR) was examined by cyclic voltammetry (CV). The MOR activity of the PtRu/C was significantly improved after each oxidation step of the redox treatment cycles. The enhanced catalytic activity was found to be quite stable in chronoamperometry (CA) measurements. CV, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results strongly suggested that the improved catalytic activity was due to the formation of a stable c-RuO_x (x = 2-3) domain during the oxidation treatments. A bifunctional based mechanism was proposed for the MOR on the oxidized PtRu/C catalysts. Formation of Ru-OH species on the surface of c-RuO_x domains was suggested as stale sites for the oxidation of carbon monoxide adsorbed on the Pt catalytic sites.     

A history of numerical modelling of the Wairakei geothermal field

The history of computer modelling of the Wairakei geothermal field is reviewed. It covers the development of lumped-parameter models during the 1970s and then discusses the evolution and first applications of geothermal reservoir simulation techniques. The development of reservoir models of Wairakei at the University of Auckland began in the early 1980s; current models produces good matches against field data. Many future scenarios have been run using the University's models and have been presented at various regulatory hearings. The general conclusion from these scenarios is that Wairakei can continue producing electricity at the current level for at least another 50 years, and if Wairakei is shut down after 100 years of operation it will recover to its pre-exploitation state after a further 300 years.     

Using 10 Gb/s remodulation DPSK signal in self-restored colorless WDM-PON system

In this investigation, we propose and experimentally demonstrate the remodulation technique using DPSK format in both downlink and uplink traffics with high extinction ratio (ER) in colorless WDM-PON; together with a simple self-restored architecture against fiber fault. Error free operation was achieved in a 20-km-reach 10-Gb/s WDM-PON without dispersion compensation. Comparison with other wavelength remodulation schemes for WDM-PONs is also performed, showing the proposed scheme can be a potential candidate for next generation wavelength reuse WDM-PONs. In addition, the performance of self-protection has also been discussed and analyzed.     

The p38 and NFκB signaling protein activation involved in glycitein protective effects on isoproterenol-treated H9c2 cardiomyoblast cells

Heart disease (HD) is greatly associated with gender and clinical evidence shows that increased serum norepinephrine levels are found in patients with HD. This study investigates the cardio-protective effect of glycitein, a selective estrogen receptor modulator (SERM) from soy bean extract, on H9c2 cardiomyoblast cells treated with isoproterenol (ISO, a norepinephrine analog). The image data and results from western blotting showed that ISO treatment was capable of inducing cellular apoptosis, especially the mitochondrial dependent pathway. Glycitein treatment could suppress mitochondrial pro-apoptotic proteins expression including caspase-9 and caspase-3 in H9c2 treated with ISO. In contrast, several survival proteins were expressed in H9c2 cells treated with glycitein, such as phosphor (p)-Akt, p-Bad and Akt. We confirmed that the protective role of glycitein was partially mediated through the expression of p-38 and NFκB proteins by adding several pathway inhibitors.     

Spectral tomography of concrete structures based on impact echo depth spectra

This paper proposes a spectral tomography for nondestructive test of concrete structures based on the spectral data of impact echo test. Firstly, a mesh is drawn on the surface of the concrete. Then, impact echo tests are performed at the grids. The recorded signals are processed to obtain the spectra of the concrete. The spectra are further transformed into the depth spectra and assembled into 3D volume data. Finally, spectral tomography is applied to the volume data to construct the image of the concrete structure for arbitrary cross-sections. Both numerical and experimental tests are performed to verify the effectiveness and reliability of the proposed imaging method. It is seen that the spectral tomography can be used to show the internal cracks in the concrete specimens successfully.     

Effect of organoclay on the mechanical / thermal properties of microcellular injection molded polystyrene–clay nanocomposites

An organically modified montmorillonite was compounded with polystyrene (PS) in a twin-screw extruder. The organoclay polystyrene nanocomposites were then injection molded by conventional and microcellular methods. Nitrogen was used as the blowing agent. The effect of organoclay content on the mechanical and thermal properties was investigated. The results showed that when the MMT content was 1 wt.%, the nanocomposites have maximum tensile strength, wear resistance, and cell density. Moreover, the addition of organoclay increases the glass transition and decomposition temperature of the nanocomposites. The XRD results showed that the layer spacing of the nanocomposites decreases by comparison with the organoclay. TEM pictures showed that MMT is well dispersed within the PS matrix.