Noise exposure and hearing conservation for farmers of rural Japanese communities

Agricultural mechanization in Japan has progressed dramatically since 1955 with the introduction of tractors, harvesters, and processing machines. These technological developments have resulted in an increase in exposure to sources of noise that are not only annoying, but damaging to hearing. The present study was undertaken to determine, whether Japanese farmers are at risk for noise-induced hearing loss in comparison with office workers, and by evaluating the present conditions regarding occupational noise levels among agricultural workers.The results suggest that farmers, especially male farmers, have a high prevalence of hearing loss in the higher frequency ranges. Daily noise exposure levels in L_Aeq ranged from 81.5 to 99.1 dBA for tea harvesting and processing, and from 83.2 to 97.6 for sugar cane harvesting. Taking into account their rather long working hours and excessive noise from farm machinery, it is concluded that farmers are at risk for noise-induced hearing loss. These findings clearly indicate a strong need for implementation of hearing conservation programs among agricultural workers exposed to machinery noise.     

Chetracin A,a new epipolythiodioxopiperazine having a tetrasulfide bridge from chaetomium abuense and C. retardatum

A new epipolythiodioxopiperazine, designated chetracin A, exhibiting remarkable cytotoxicity, was isolated from Chaetomium spp. The compound was proved to have the 11α 11′α-dihydroxychaetocin nucleus by NMR and correlation reactions and found to have the tetrasulfide bridge by X-ray analysis.     

Photocurrents of solar cells sensitized by aggregate-forming polyenes: Enhancement due to suppression of singlet–triplet annihilation by lowering of dye concentration or light intensity

Titania-based Grätzel-type solar cells were fabricated by the use of polyene dyes with various transition dipole moments. In the dye having the largest transition dipole among the samples, an aggregate was readily formed through dispersive interaction, and the photocurrent was increased when the dye concentration or the light intensity was lowered. This observation was ascribed to the suppression of the singlet–triplet annihilation reaction. In the dye having the smallest transition dipole, there was no sign of aggregate formation, and the photocurrent was decreased when the dye concentration or the light intensity was lowered.     

Application of a micro multiphase laminar flow on a microchip for extraction and determination of derivatized carbamate pesticides.

Determination of carbamate pesticides such as carbaryl, carbofuran, propoxur and bendiocarb was demonstrated on a microchip with newly designed microchannels developed for efficient solvent extraction. The pesticides were hydrolyzed to corresponding naphthols, coupled with p-nitrobenzenediazonium fluoroborate reagent, and then extracted into 1-butanol as colored azo derivatives and detected with a thermal lens microscope. Optimum flow rates for the aqueous and organic phases were evaluated in the continuous-flow chemical process established in the microchip. The calibration lines showed good linearity in the range of concentrations of 0.03 - 3 ppm (10(-7) - 10(-5) M) and a mass detection limit down to a nanogram level was achieved that is at least two orders of magnitude lower than the LODs for conventional spectrophotometric methods. Azo derivatives of the pesticides were successfully separated and identified by micellar electrokinetic chromatography (MEKC) using a sample prepared on a bulk scale.     

Cycloleonurinin, a cyclic peptide from Leonuri Fructus

From Leonuri Fructus, a cyclic peptide composed of twelve amino acid residues was isolated. The sequence of the residues was established by mass spectroscopy and by the use of a protein sequencer for the partial hydrolysates obtained by alpha-chymotrypsin.     

The organic solvent effect on phosphomolybdic acid and its analytical application

The ultraviolet spectra of phosphomolybdic acid in aqueous and mixed solvent systems were studied. The spectra are profoundly affected by the addition of organic solvents such as tetrahydrofuran, ethanol and their homologues and eventually exhibit an absorption maximum at 310 run. The formation of phosphomolybdic acid was found to be quantitative even with low concentrations of molybdate ions (ca. 10(-4)M) at pH about 3. By using these facts, a simple method for direct spectrophotometric determination of phosphate ion has been developed.     

Local environment and property of water inside the hollow cylinder of a lipid nanotube

We investigated the local environment of water confined inside the hollow cylinder of lipid nanotubes (LNTs) by time-resolved fluorescent measurements and attenuated-total-reflectance infrared (ATR-IR) spectroscopy. The LNT was obtained by self-assembly of cardanyl glucosides in water at room temperature and had an open-ended cylindrical nanospace with a diameter of 10-15 nm, a length of 10-100 microm, and hydrophilic inner and outer surfaces. We introduced a fluorescent probe of 8-anilinonaphthalene-1-sulfonate into the confined water and observed an extremely slow dynamic Stokes shift with a correlation time of 1.26 ns, which was 2-3 orders of magnitude longer than that of bulk-phase water. From the peak shift of the fluorescent spectrum, the local solvent polarity (ET(30)) of the confined water was estimated as 50 kcal/mol, which is 20% lower than that in bulk water. ATR-IR measurements showed that the hydrogen-bond network of water inside the LNT was more developed than that in bulk water at room temperature, which is in contrast to the water in other self-assembled confined geometries, such as Aerosol-OT (AOT) reversed micelles.     

Spin polarization of photoelectrons from solid cesium by circularly polarized light

The spin polarization of photoelectrons excited in cesium metal by circularly polarized light is discussed using group theoretical methods. Calculations of the spin polarization have been performed for direct transitions at the-point and between, and states. The results suggest that photoelectrons excited in monocrystalline Cs could have a high degree of spin polarization which depends both on the wave vector of the electrons and on the energy of the absorbed photon. Measurement of this polarization should allow the spin-orbit splitting of different energy bands to be determined.