Stereoselective reduction of (±)-bicyclo[3.3.1]nonane-2,6-dione by microorganisms

The biotransformation of (±)-bicyclo[3.3.1]nonane-2,6-dione by Aspergillus niger and Glomerella cingulata was investigated. The diketone was reduced to the ketoalcohol 2-endo-hydroxy-bicyclo[3.3.1]nonane-6-one and the diol endo,endo-bicyclo[3.3.1]nonane-2,6-diol respectively. Endo,endo-bicyclo[3.3.1]nonane-2,6-diol and ketoalcohols produced by G. cingulata had high optical purity, on the other hand, reduction by A. niger yielded optically active (-)-(1R, 2S, 5R, 6S)-bicyclo[3.3.1]nonane-2,6-diol(99·9% e.e.). © 1998 SCI     

A design scheme of discrete robust PID control systems and its application

PID controllers have been widely used in many chemical processes. Because they have only three control parameters, we can easily understand their physical meanings. However, it is difficult to tune their parameters in the case where the control system has uncertainties, for example, modeling errors, system fluctuation, and so on. Therefore, we propose a design scheme of discrete robust PID controllers in this paper. That is, we design a PID controller in connection with the generalized minimum variance control (GMVC) scheme, and present a scheme on how to design a weighting factor included in the GMVC criterion from the viewpoint of robust stability. Furthermore, we investigate the behavior of the proposed control scheme by applying it to an air pressure control system. © 1999 Scripta Technica, Electr Eng Jpn, 128(4): 77–83, 1999     

Effects of extraction and reconstitution of ryegrass juice on fermentation,digestion and in situ degradation of pressed cake silage

Primary growth of Italian ryegrass was fractionated into green juice and pressed cake (PC). PC was ensiled either directly or after reconstitution with the juice which was spray dried and then added to water before ensiling (RPC). This process was aimed at distinguishing between chemical (removal of nutrients) and physical (mechanical disintegration) effects of fractionation. Two additional wilted silages were prepared from long cut or chopped Italian ryegrass (WL and WC, respectively). The fermentative quality, digestion and in situ degradation of dry matter for the four silages were compared. WC, RPC and PC silages indicated lactate-rich fermentation while WL silage had a comparatively low lactate content. PC silage had a lower (P<0·05) pH value with lower (P<0·05) amounts of organic acids compared with WC and RPC silage, suggesting that removal of buffering components with the juice had greater effects than shredding on fermentation of PC silage. The digestibility of protein was lower (P<0·05) in PC than WL silage but the reduction was compensated for in RPC silage. Ruminal concentrations of total volatile fatty acids were the highest (P<0·05) when goats fed WL silage while those on the other silages had similar concentrations. Ruminal pH was lower (P<0·05) in goats fed PC than WC silage and the difference was not fully reversed by reconstituting the juice to PC. Juice extraction decreased (P<0·05) the soluble fraction and the rate of disappearance of dry matter in the rumen but the potential degradability was not different among treatments. These results suggest that both chemical and physical changes due to the fractionation affect the characteristics of digestion of PC silage while the removal of nutrients has a major role in the modified silage fermentation. © 1997 SCI.     

Study of the Differences Between Two Salt Qualities on Microbiology,Lipid and Water-Extractable Components of Momoni,a Ghanaian Fermented Fish Product

Lipid oxidation and low final product quality observed during processing and storage of a Ghanaian fermented fish product were investigated with respect to the quality of salts used in the curing procedures, namely crude solar salt and refined salt. On analysis of differences in composition, refined salt had a lower moisture and microbial load than crude salt. Differences after fermentation and storage of both refined-salted and crude-salted fish were as follows: decreases in water activity of fish during processing was slower with crude salt than with refined salt; volatile basic nitrogen and total microbiological counts were higher in crude-salted fish; the polyamine of highest concentration in crude-salted samples was histamine, whilst cadaverine concentration dominated in fish fermented with refined salt. TBARS and peroxide values of the extracted total lipids increased during processing. Free fatty acid and diglyceride concentrations were higher in the crude-salted fish than in the samples with refined salt. Poly-enoic fatty acid levels were higher in the samples fermented with refined salt, whilst the levels of total cholesterol oxides were higher in the crude-salted samples.     

Properties of chelating resins prepared by addition of 1,4,8,11-tetraazacyclotetradecane-5,7-dione to epoxy groups of poly(glycidyl methacrylate)s crosslinked with oligoethylene glycol dimethacrylates

In order to improve Cu(II) adsorption ability of chelating resins based on a macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane-5,7-dione (L) bound to crosslinked copolymers, the resins were prepared by reaction of L with poly(glycidyl methacrylate)s crosslinked with ethylene glycol dimethacrylate (1G), tetraethylene glycol dimethacrylate (4G) or nonaethylene glycol dimethacrylate (9G). By systematically changing the amounts of each crosslinker (degree of crosslinking) and of isobutyl acetate (IBA) as diluent in the suspension polymerization of the monomers, precursory copolymers with various degrees of crosslinking as well as with different specific surface areas (SSAs) were prepared, and then L was introduced into them. Ligand contents, SSAs, and Cu(II) adsorption abilities of the resulting resins were evaluated, and it was clarified that resins derived from precursors (prepared by using 4G or 9G in the presence of 120–160 vol % of IBA) exhibit high capacities for Cu(II), whereas the capacities of resins crosslinked with 1G are not so high. Further detailed study on the uptake of metal ions using the resins RG4D(10)-140 and RG9D(10)-140 (derived from the precursors prepared by using 10 mol % of the respective crosslinkers 4G and 9G in the presence of 140 vol % of IBA) showed that RG9D(10)-140 is much superior to RG4D(10)-140 in the column-mode adsorption of Cu(II). These results indicate that not only the selection of the suitable crosslinker but also the use of a pertinent amount of the diluent are very important in improving the complexing abilities of the polymer-bound L. © 1996 John Wiley & Sons, Inc.     

Effects of motion image stimuli with normal and high frame rates on EEG power spectra: comparison with continuous motion image stimuli

The human electroencephalographic (EEG) power spectra when viewing visual stimuli of a real motion image and of motion images with 60 frames/s (fps) and 240 fps were investigated. The EEG spectra in response to the 240 fps motion image stimuli were more similar to those of the real motion image stimuli than those of the 60 fps stimuli. This high frame rate (240 fps) motion image is considered to have a possibility of providing perceptions of motion image quality that are close to the impression upon looking at real world scenes.     

Energy cost of pushing a wheelchair on various gradients in young men

This study investigated the effects of pushing a wheelchair on the energy cost of walking (C_w; defined as the ratio of the steady-state oxygen consumption to the walking speed) and economical speed (ES) on the level and ±5% gradients. Eight pairs were formed from twelve young men to minimize variation in body weight between pushing and assisted participants. The State Trait Anxiety Inventory (STAI) test was conducted to evaluate wheelchair occupants' anxiety before and after each trial. The C_w values were significantly higher when pushing a wheelchair on the uphill gradient at more than 45 m/min. ES was significantly lower when pushing a wheelchair on the level (−8.5%) and uphill gradient (−9.1%), but not on the downhill gradient (−0.3%). Individual ES was also estimated using the concept of “Froude number”, and “estimated” ES was significantly correlated with “measured” ES even when pushing a wheelchair on the downhill gradient. The STAI score was not significantly increased except at 105 m/min, regardless of gradient. These results indicated that the fastest walking speed without an enhancement in wheelchair occupants' anxiety corresponds to ES when pushing a wheelchair with a seated occupant on all gradients, at least in young fit men.     

Endoscopic trigonoplasty for primary vesico-ureteric reflux

OBJECTIVE: To investigate the surgical results of endoscopic trigonoplasty in patients with primary vesicoureteric reflux. PATIENTS AND METHODS: Records were reviewed for 12 patients who underwent endoscopic trigonoplasty between February 1992 and February 1994. Of the 12 patients, 11 were female; one was a child and nine had unilateral disease. From 15 renoureteric units, grade I vesico-ureteric reflux was demonstrated in five, grade II in six and grade III in four. The ureteric orifices were approximated close to the midline via the urethral route and two trocars on the abdomen achieved pneumobladder. RESULTS: The mean surgical time was 178 +/- 52 min; this lessened as the learning curve developed. Intra-operative complications in three patients were all caused by trocar placement. Eleven patients required analgesics for one post-operative day only. No post-operative dilatation of the upper urinary tract was demonstrated. Vesico-ureteric reflux was eradicated in all patients. CONCLUSIONS: Endoscopic trigonoplasty is a minimally invasive procedure with a high cure rate. By not destroying the normal vesico-ureteric junction, post-operative obstruction cannot occur. We believe that endoscopic trigonoplasty is a feasible procedure for patients with vesico-ureteric reflux.