Five years operating experience of large scale distillation test plant made of carbon steel

The distillation test plant operated since April 14, 1972 during 94.2% of the work day has the capacity to treat 1,000 cu. meter/day of sea water, to produce 850t of fresh water of excellent quality, leaving 150t of concentrated brine containing 20% solid matter. Raw sea water was pretreated to prevent scale formation and corrosion of materials in distillation. Patents have been granted in Japan, USA, United Kingdom, West Germany, France, Italy, etc. (1).This method enables use of a base metal such as common steel for construction with the following advantages:Capital investment is cheaper.No galvanic corrosion arises.Mechanical structure is rigid.Contamination of poisonous heavy metals is avoidable.Upper limit of temperature is higher.Amount of raw sea water is smaller.Amount of exhaust brine is smaller.     

Determination of the coefficient of friction in forging of porous metals from ring compression

An analysis of ring compression of porous metals was made on the basis of the plasticity theory for porous metals previously proposed by the authors. The change in geometry of rings with various porosities was obtained for various coefficients of friction. Experiments on ring compression were carried out using sintered copper powder metals. The coefficient of friction was determined for various lubricants and a proper lubricant for forging of porous metals was found.     

Influence of Si/Al ratio on the activity and durability of Pd-ZSM-5 catalysts for nitrogen oxide reduction by methane

The selective reduction of NO by methane on Pd-ZSM-5 catalysts with different Si/Al and Pd loadings was examined in the presence and absence of water vapor. At low Si/Al, NO reduction activity was high and stable, while at higher Si/Al, activity was lower and deactivation was significant. The deactivated samples showed PdO bands in the Raman spectra, which indicated that dispersed Pd cations play a key role in NO reduction. The influence of Si/Al on the stability of dispersed Pd cations suggested the importance of Al site pairs for the stable dispersion of Pd cations.     

4-Hydroxyderricin from Angelica keiskei roots induces caspase-dependent apoptotic cell death in HL60 human leukemia cells

The ethyl acetate (EtOAc)-soluble fraction of a methanol extract of Angelica keiskei roots exhibited cytotoxic activity against 4 human tumor cell lines, HL60 (leukemia), CRL1579 (melanoma), A549 (lung), and AZ521 (stomach). Nine chalcones (1-9), 5 coumarins (10-14), and 4 flavanones (15-18), isolated from the EtOAc-soluble fraction, were examined for their cytotoxic activities in the 4 human tumor cell lines. Among the compounds tested, 4-hydroxyderricin (2), a major chalcone constituent, exhibited potent cytotoxic activities in all 4 tumor cell lines with IC(50) values of 5.5 μM (HL60), 4.8 μM (CRL1579), 10.2 μM (A549), and 4.2 μM (AZ521). 4-Hydroxyderricin induced early apoptosis in HL60 cells, observed as membrane phospholipid exposure in flow cytometry. Western blot analysis showed that 4-hydroxyderricin markedly reduced the levels of procaspases-3, -8, and -9, while increasing the levels of cleaved caspases-3, -8, and -9. In addition, 4-hydroxyderricin exhibited potent inhibitory activity on human DNA topoisomerase (Topo) II (IC(50) 21.9 μM). These results suggested that 4-hydroxyderricin induces apoptotic cell death in HL60 via both the death receptor-mediated pathway and the mitochondrial pathway by, at least in part, Topo II inhibition. 4-Hydroxyderricin may therefore hold promise as an effective antitumor agent.     

Ultrastructural and histochemical evaluation of appositional mineralization of circumpulpal dentin at the crown- and root-analog portions of rat incisors

Mineralization of circumpulpal dentin has been interpreted in such a way that predentin matrix is abruptly converted to almost fully mineralized dentin at the mineralization front. A group of investigators pointed out the existence of intermediary layer along the mineralization front of rat incisor dentin and claimed that dentin mineralization is a rather transient process. Owing to a paucity of information, however, the entity of transient mineralization of dentin has remained elusive. Here we confirmed the existence of a lightly mineralized layer (LL) along the mineralization front of rat incisor dentin, recognizable by both light and electron microscopy, in routinely processed specimens. LL less than 3?μm thick was shown to be located along the mineralization front of crown-analog dentin and tapered out toward the root analog of the incisor. Electron microscopy revealed that mineral deposition first occurred in the non-collagenous matrix of LL and that mineralization of collagen fibers took place sometime later at the conventional mineralization front. Microscopic appearance of the mineral phase of LL varied considerably depending on the histological processing of ultrathin sections, thus explaining the inconsistent interpretation of dentin mineralization in previous studies. These data suggest that mineralization of circumpulpal dentin in rat incisors proceeds in a stepwise or a transient manner, initiated by crystal deposition in the non-collagenous matrix followed by massive mineral deposition in collagen fibers at the mineralization front. The thickness of LL where only the non-collagenous matrix is mineralized may vary in relation to differences in the local non-collagenous matrix and also the rate of collagen mineralization in the respective portions of circumpulpal dentin.     

Hydrogen sensing properties of protective-layer-coated single-walled carbon nanotubes with palladium nanoparticle decoration

Protective-layer-coated single-walled carbon nanotubes (SWNTs) with palladium nanoparticle decoration (Pd-SiO(2)-SWNTs) were fabricated and their sensing properties for hydrogen (H(2)) were investigated. SWNTs were coated with a 3-4?nm thick SiO(2) layer by pulsed laser deposition and subsequently decorated with Pd nanoparticles by electron beam evaporation. Even though the SWNTs were completely surrounded by a protective layer, Pd-SiO(2)-SWNTs responded to H(2) down to a concentration of 1 part per million. Compared with the Pd nanoparticle-decorated SWNTs without a protective layer (Pd-SWNTs), Pd-SiO(2)-SWNTs exhibited highly stable sensor responses with variations of less than 20%; Pd-SWNTs showed a variation of 80%. The density of the Pd-SWNTs significantly decreased after the sensing test, while that of the Pd-SiO(2)-SWNTs with the netlike structure remained unchanged. The hydrogen sensing mechanism of the Pd-SiO(2)-SWNTs was attributed to the chemical gating effect on the SWNTs due to dipole layer formation by hydrogen atoms trapped at the Pd-SiO(2) interface. Moreover, the relationship between H(2) concentration and sensor response can be described by the Langmuir isotherm for dissociative adsorption.     

A quantification and confirmation method of patulin in apple juice by GC/MS

A sensitive and selective method for quantification and confirmation of patulin in apple juice by GC/MS was developed. By this method, patulin was precisely determined and confirmed down to the level of 1 and 5 microg/kg in samples, respectively. Patulin was extracted with ethyl acetate from a sample and then hexane was added to the concentrated extract solution. Significant amounts of insoluble impurities were filtered off, followed by further clean-up by solid-phase extraction with combined silica gel and Florisil cartridges. The filtration step in a low-polarity condition was very effective to remove the impurities in the sample extract solution. The eluate from the cartridges was evaporated to dryness under reduced pressure and patulin was determined and confirmed by GC/MS after derivatization with 2.5% N,O-bis(trimethylsilyl)trifluoroacetamide ethyl acetate solution. Patulin was determined in the selected ion monitoring mode (m/z 226) and confirmed in the SCAN mode (m/z 40-340). The recovery from apple juice spiked with 10-500 microg/kg ranged from 93.4 to 100%. The limits of detection and quantification were 0.1 (S/N = 3) and 1 microg/kg (S/N = 30) of patulin in samples, respectively. Levels down to 5 microg/kg of patulin in sample were readily confirmed.     

Polymerase chain reaction assay for detection of sheep and goat meats

Polymerase Chain Reaction (PCR) was applied to a qualitative differentiation between sheep, goat and bovine meats. Oligonucleotide primers were designed for the amplification of sheep satellite I DNA sequence. The PCR amplified 374 bp fragments from sheep and goat DNA, but no fragment from bovine, water buffalo, sika deer, pig, horse, rabbit and chicken DNA. Sheep DNA (10 pg) was detected by 4% agarose gel electrophoresis following PCR amplification. Althoug cooking of the sample meats reduced the PCR products, sheep DNA was detected in the meat heated at 120°C. In order to differentiate between sheep and goat meats, nucleotide sequences of the PCR products were determined directly by cycle sequencing. The sequence of PCR products showed 92% of homology between sheep and goat. They were differentiated by ApaI digestion of the PCR products because sheep had one ApaI site and goat had no site in the PCR products.     

Size effect on systemic and mucosal immune responses induced by oral administration of biodegradable microspheres

Induction of systemic and mucosal immune responses following oral administration of biodegradable poly(D,L-lactic acid) (PDLLA) microspheres containing a model antigen, ovalbunin (OVA) was studied using microspheres with different average diameters of 0.6, 1.0, 4.0, 7.0, 11.0, 15.0, 21.0, and 26.0 microns. They were prepared from double emulsion with the solvent evaporation method, followed by size fractionation on counterflow elutriation. OVA was released from the microspheres in vitro over 80 days, irrespective of their size. Production of the serum anti-OVA IgG antibody and secretory OVA-specific IgA antibody in the mice gut was assessed following the oral administration of PDLLA microspheres containing OVA. Microspheres with a diameter of 4.0 microns enhanced the serum antibody in contrast with that of free OVA, but were not effective in inducing the gut secretion of IgA antibody. On the other hand, OVA-containing microspheres with a diameter of 7.0 microns enhanced IgA secretion to a significant extent compared with free OVA, whereas those with 26.0 microns in diameter were ineffective. Body distribution study revealed that the amount of microspheres taken up into Peyer's patches (PP) increased with the increasing size up to 11.0 microns, thereafter decreased, and finally became zero when their diameters were 21.0 microns or larger. The microspheres taken up into PP were translocated to the spleen, but no microspheres were noticed in the spleen when the size was larger than 5 microns. After being taken up inot PP, microspheres < 5 microns in diameter seemed to be transported to the spleen, a systemic lymphoid tissue, where the released antigen stimulated a serum antibody response, but larger microspheres probably remained at PP without being translocated to the spleen over the course of their antigen release, leading to induction of IgA secretion. It was concluded that the body distribution pattern of microspheres following the PP uptake was a key factor to regulate the induction of systemic and mucosal immune responses.