OBJECTIVE To assess middle ear aeration after total mastoid obliteration using bone pate and hydroxyapatite performed at the second stage of intact-canal-wall (ICW) tympanoplasty. STUDY DESIGN Retrospective study. SETTING Tertiary referral hospital. PATIENTS Forty-two ears with cholesteatoma underwent the obliteration. Computed tomography (CT) scan 1 week before the second-stage operation...

The present study addresses the effects of oxygen exposure on the aerobic and anaerobic respiratory activity of Desulfovibrio desulfuricans strain DvO1. This strain was isolated from the highest sulfate-reduction positive most-probable-number dilution (10(6)) of an activated sludge sample, which had been subjected to 120 h of continuous aeration. Washed cell suspensions of strain DvO1 were aera...

The ultrastructure of sectioned cells of mutant and wild type Rhodopseudomonas spheroides has been examined by electron microscopy. The characteristic vesicles associated with the presence of bacteriochlorophyll were found in wild type cells grown with low aeration. These were also found in mutant TA-R which forms bacteriochlorophyli under high aeration. None of the mutants with blocks in bacte...

The ultrastructure of sectioned cells of mutant and wild type Rhodopseudomonas spheroides has been examined by electron microscopy. The characteristic vesicles associated with the presence of bacteriochlorophyll were found in wild type cells grown with low aeration. These were also found in mutant TA-R which forms bacteriochlorophyli under high aeration. None of the mutants with blocks in bacte...

In order to unravel the effect of aerated irrigation on soil dissolved organic matter (DOM) fluorescence characteristics, and humification degree, a randomized block experiment was conducted with three factors two-level design, i.e., two rates (0.6 1.0 times crop evaporation pan coefficient, W1 W2), nitrogen application (225 300 kg hm−2, N1 N2), aeration (15% 0% in control treatment, A1 A0). Fl...

BACKGROUND Bacillus anthracis produces two catecholate siderophores, petrobactin and bacillibactin, under iron-limited conditions. Here, we investigate how variable iron and oxygen concentrations influence the biosynthetic output of both siderophores in B. anthracis. In addition, we describe the differential levels of transcription of select genes within the B. anthracis siderophore biosyntheti...

In this research, constructed wetlands were applied to remove the nitrogen of lightly polluted wastewater from a wastewater treatment plant in Tangshan. The results showed that a favorable removal effect of nitrogen could be obtained through constructed wetland. Moreover, the aeration device added to the bottom could increase the removal rates of ammonia nitrogen in lightly polluted wastewater,...

A laboratory-scale experiment presents data that reveal the temporal characteristics of solids, biochemical oxygen demand (BOD5) and volatile fatty acids (VFAs) in the aerated liquid swine manure for minimizing odor generation potential during 190-day storage. The performance of 15-day aeration of liquid manure with initial total solids (TS) content from 0.5% to 4.0% was examined at low-intensi...

This study investigated the influence of dissolved oxygen concentration and aeration time on nitrification and nitrite accumulation in an attempt to optimize the recently developed biological-partial-nitritation process for the treatment of strong nitrogen wastewaters. Investigation of dissolved oxygen concentration on ammonium and nitrite oxidation was carried out in a batch reactor. The disso...