A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was to determine how well a ...prototypical volume CT (VCT) scanner with a flat-panel detector system defines fine structures in temporal bone.
Four partially manipulated temporal-bone specimens were imaged by use of a prototypical cone-beam VCT scanner with a flat-panel detector system at an isometric resolution of 150 microm at the isocenter. These specimens were also depicted by state-of-the-art multisection CT (MSCT). Forty-two structures imaged by both scanners were qualitatively assessed and rated, and scores assigned to VCT findings were compared with those of MSCT.
Qualitative assessment of anatomic structures, lesions, cochlear implants, and middle-ear hearing aids indicated that image quality was significantly better with VCT (P < .001). Structures near the spatial-resolution limit of MSCT (e.g., bony covering of the tympanic segment of the facial canal, the incudo-stapedial joint, the proximal vestibular aqueduct, the interscalar septum, and the modiolus) had higher contrast and less partial-volume effect with VCT.
The flat-panel prototype provides better definition of fine osseous structures of temporal bone than that of currently available MSCT scanners. This study provides impetus for further research in increasing spatial resolution beyond that offered by the current state-of-the-art scanners.
The application of the high rate ADUF (anaerobic digestion-ultrafiltration) process to brewery effluent was investigated over 80 d. A stable feed of 15 kg COD per m3.d was attained at hydraulic ...residence times of 0.5-0.8 d, yielding COD removals of 96-99 per cent. Urea was needed to compensate for nutrient deficiency. Sludge dormant for 2 months was reactivated swiftly, reaching a loading rate of 8 kg COD per m3.d within 7 d of restarting. UF flux was affected by biomass suspended solids, metabolic conditions in the digester, and linear flow velocities across the membrane. Fluxes rose with linear velocity and fell when biomass values exceeded 20 g per litre or digester disruption. Values of 10-18 litres per m2.h were maintained without chemical cleaning. Permeate quality was high with COD of 75 mg per litre being achieved.
ADUFR (anaerobic digestion ultrafiltration) is a membrane-assisted process for positive separation of biomass from the treated effluent. Pilot and full-scale ADUFR studies were carried out on a ...maize-processing effluent (15 kgCOD/m3) at the Meyerton mill of Messrs. African Products, South Africa. The results after 15 months of full-scale operation have illustrated the merits of the process for the production of a colloid-free effluent at a mean COD removal efficiency of 97%. The permeate flux varied in the range 37 to 8 l.m−2.h−1 at 35°C, inlet pressure of 450 kPa, linear tube velocity of 1.6 m/s and digester suspended solids concentration of 21 kg/m3. Periodic chemical cleaning of the unsupported tubular polyethersulphone membranes with EDTA was only commenced after 13 months operation. A mean plant space load rate of 3 kgCOD.m−3.d−1 guaranteed reliability to withstand high COD shock loadings due to variations in the feed load. Bio-membrane separation technology of this nature holds important economic advantages for the treatment of a wide spectrum of organic industrial effluents.
The chaperonin family of proteins, which includes GroEL protein of E. coli, yeast heat shock protein (hsp-60) and the ribulose-1-5-bisphosphate carboxylase (Rubis Co.) subunit binding protein of ...plant chloroplasts, shows strong sequence homology to the Chinese hamster ovary (CHO) mitochondrial P1 protein. We have identified a 60 kDa protein from bovine kidney which by N-terminal sequencing gives the amino acid sequence AKDVKFGADARALLMLQGVDLLADA. Bovine whole kidney membranes were delipidated, solubilized with octyl glucoside and fractionated over an affinity column using the amiloride analog 5-N pyrazine amiloride as the ligand. After extensive washing with 200 mM NaCl, the column was eluted with pH 4.0 buffer. Analysis of column fractions on a 7.5% polyacrylamide gel revealed 3-4 bands with a predominant band at 60,000 Da. Amino acid analysis after transfer to immobilon membranes demonstrated sequence identity to the human HSP (60), extending 24 amino acids from the N-terminus, but lacking the leader sequence. These data indicate that a processed form of a protein related to the human HSP (60) chaperonin is associated with a membrane fraction in the mammalian kidney, and that the processed form of the protein binds strongly to an amiloride affinity support.
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