Effect of aging on urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone

19-Noraldosterone, recently shown to be produced in the human adrenal gland, possesses potent mineralocorticoid and hypertensinogenic activity. A possible precursor, 18,19-dihydroxycorticosterone, has been identified in human urine, with both steroids acutely regulated by the renin-angiotensin system. The secretion of aldosterone declines with advancing age. To elucidate the effect of aging on the urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone, we measured their urinary concentrations in 51 normotensive subjects aged 20-70 years. We observed significant negative correlations between age and the urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone (r = -0.69, r = -0.65, P < 0.05, respectively). Urinary and plasma aldosterone and PRA similarly decreased with aging. These results suggest that 19-noraldosterone may be chronically regulated in part by the renin-angiotensin system.     

Differential Detection of MSK with Nonredundant Error Correction

A proposed scheme for differential detection of MSK with nonredundant error correction utilizes the output detected from the difference in phase between alternate signaling intervals, along with the output of the conventional differential detector, in accordance with the concept of a convolutional error correcting code. Theoretical analysis and experimental results show that the degradation from coherent detection is about 0.1 dB at a 10 dB signal-to-noise ratio.     

Interaction of caffeine with montmorillonite

In this study, caffeine was adsorbed onto montmorillonite and the surface of the montmorillonite was observed before and after the adsorption. Observations were performed by X-ray diffractometry (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and scanning probe microscopy (SPM). Measurement of the interlayer distance by XRD revealed that it narrowed to 1.09?nm after caffeine adsorption. Adsorption of a small amount of caffeine causes a broadening of d₀₀₁ peaks. This suggested that caffeine molecules were adsorbed into the interlayer space in part, resulting in an irregular layer stacking. The results of SPM observations of caffeine-adsorbed montmorillonite showed the existence of protrusions that are different from minerals on the surface of montmorillonite and suggested a possibility that the protrusions were caffeine molecules adsorbed onto the surface of montmorillonite. DRIFTS demonstrated that the intensity of peaks assigned to Si–OH and siloxane decreased with the increase in the amount of caffeine adsorbed. These results suggested that caffeine molecules were adsorbed both into the interlayer space and onto the surface and interacted with Si–OH and siloxane, in particular. These findings will help us to select ions to be held in the interlayer space and organic compounds to improve the amount of adsorption when montmorillonite is used in the manufacture of caffeine-free drinks and foods.     

Bandgap modifications by lattice deformations in β-FeSi2 epitaxial films

The modifications of direct transition energies by lattice deformations were investigated in β-FeSi₂ epitaxial films, polycrystal films and single crystal, systematically. The lattice deformations depending on thermal annealing temperature (T_a) were observed in β-FeSi₂ epitaxial films. In photoreflectance (PR) measurements, the direct transition energies of the epitaxial films shifted to lower energies as the T_a increased. The polycrystal films did not show the lattice deformation and the shift of direct transition energies. These results show that the direct bandgap is modified by the lattice deformation originating from the lattice mismatch at the hetero-interface of β-FeSi₂/Si.     

Characterization of terraces and steps on Cl-terminated Ge(111) surfaces after HCl treatment in N2 ambient

Germanium (Ge) is a promising substrate for semiconductor devices in the near future. However, wet-chemical preparations that enable the control of the structure of the Ge surface have not yet been developed. In this study, the surface structure of Ge(111) after HCl treatment is characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning tunneling microscopy (STM). XPS spectra revealed that purging with inert gas, such as nitrogen, is necessary to obtain a Ge surface free of oxide, probably because dissolved oxygen from air rapidly oxidizes the surface. Cl-terminated Ge surfaces are microscopically rough, but are composed of terraces and steps, as revealed by magnified STM images. Step edges run not along specific directions reflecting the crystallographic nature of the (111) surface but randomly. Many atomic-scale protrusions with the height of around 0.1 nm are dispersed on terraces. They are likely to be impurities such as carbon contaminants and water on Cl-terminated terraces attracted by Cl atoms with high electronegativity.     

A Novel Dry Process for Simultaneous Removal of SO2 and NO from Flue Gas in a Powder‐Particle Fluidized Bed

A novel sorbent, potassium carbonate impregnated on porous fine alumina, was produced, and its reactive and regenerative properties were evaluated for dry‐type simultaneous removal of SO₂ and NO from flue gas under stack temperatures, by using a powder‐particle fluidized bed (PPFB) with I.D. of 53 mm as the reactor. High removal efficiencies for SO₂ and NO were achieved simultaneously. An apparent beneficial effect of SO₂ on the enhancement of NO removal was found based on a large amount of data. The alumina carrier was successfully regenerated and used repeatedly for the production of fresh sorbent particles. With no ammonia, low temperature, high removal efficiency, and no second waste emission as main characteristics, this dry process can be a competitive technology for pollution control of flue gas from power plants in the future.     

Adsorption and co-precipitation behavior of arsenate, chromate, selenate and boric acid with synthetic allophane-like materials

Pollution caused by boric acid and toxic anions such as As(V), Cr(VI) and Se(VI) is hazardous to human health and environment. The sorption characteristics of these environmentally significant ionic species on allophane-like nanoparticles were investigated in order to determine whether allophane can reduce their mobility in the subsurface environment at circum-neutral pH condition. Solutions containing 100 or 150 mmol of AlCl₃·6H₂O were mixed to 100 mmol of Na₄SiO₄ and the pH were adjusted to 6.4 ± 0.3. The mineral suspensions were shaken for 1 h and incubated at 80 °C for 5 days. Appropriate amounts of As, B, Cr and Se solutions were added separately during and after allophane precipitation. The results showed that As(V) and boric acid can be irreversibly fixed during co-precipitation in addition to surface adsorption. However, Cr(VI) and Se(VI) retention during and after allophane precipitation is mainly controlled by surface adsorption. The structurally fixed As(V) and boric acid were more resistant to release than those bound on the surface. The sorption characteristics of oxyanions and boric acid were also influenced by the final Si/Al molar ratio of allophane in which Al-rich allophane tend to have higher uptake capacity. The overall results of this study have demonstrated the role of allophane-like nanoparticles and the effect of its Si/Al ratio on As, B, Cr and Se transport processes in the subsurface environment.