Pilot scale demonstration of a two-stage pretreatment and bioethanol fermentation process for cotton gin trash.

A two-stage dilute acid and steam explosion (SE) pretreatment process was developed and evaluated at pilot scale for ethanol production from cotton gin trash (CGT). Optimal conditions for CGT processing were defined as 1:6 solids to liquids ratio with 9% H2SO4 wt. on solids at 180 °C for 15 min. during stage 1 with ensuing pressed fibres successively exposed to SE at 200 °C for 5 min during stage 2. SE fibres were highly acquiescent to enzyme hydrolysis (76%) in the presence of PEG 6000, yielding 381 g glucose kg-1 fibre. Simultaneous saccharification and fermentation (SSF) trials validated the selected process option and additional fed-batch SSFs confirmed titres above the minimum 4% ww-1 benchmark for economically viable distillation. The practicality of converting CGT to ethanol was demonstrated at pilot scale with titres above 4% ww-1 and a conversion efficiency of 60% t-1 dry GCT.

Survey of dental clinic patients: smoking and preferences for cessation support.

BACKGROUND: Smoking cessation interventions delivered by dental practitioners can be as effective as those delivered by general medical practitioners. However, concern that addressing smoking may cause offence to their patients is a reason cited by dental practitioners for not regularly addressing patient smoking behaviours, despite believing they should play a role in smoking cessation. This study aimed to elicit the smoking behaviour and smoking cessation preferences of dental patients to determine if these concerns accurately reflect patient attitudes. METHODS: We surveyed 726 adult dental patients attending The University of Queensland's School of Dentistry dental clinics, Brisbane Dental Hospital and four private dental practices in South-East Queensland. RESULTS: Most (80%) current daily smokers had tried to quit smoking. Smokers and non-smokers both agreed that dentists should screen for smoking behaviour and are qualified to offer smoking cessation advice (99% and 96% respectively). Almost all participants (96%) said they would be comfortable with their dentist asking about their smoking and that if their smoking was affecting their oral health their dentist should advise them to quit. CONCLUSIONS: Patients are receptive to dental practitioners inquiring about smoking behaviour and offering advice on quitting. Smoking patients showed considerable motivation and interest in quitting smoking, particularly in the context of health problems related to smoking being identified. These results should encourage dentists to raise the issue with their patients.

Survey of Australian oral health practitioners and their smoking cessation practices.

BACKGROUND: Smoking is a significant health and economic burden in Australia. Studies of smoking cessation practices in dental settings have primarily concentrated on dentists rather than other oral health practitioner (OHP) groups (dental hygienists, dental therapists and oral health therapists). The aim of this study was to measure Australian OHPs' attitudes, behaviours, interest and barriers to delivering smoking cessation interventions. METHODS: Members of the two peak professional bodies representing Australian OHPs were invited to participate in an anonymous online questionnaire. RESULTS: There were discrepancies between practitioner attitudes and current smoking cessation practices. While the majority of practitioners (90.1%) frequently screened for smoking behaviour, fewer (51.1%) assisted patients to quit smoking. The principal form of assistance was referral to Quitline (45.7%) or to a general medical practitioner (44.4%). The most prevalent barriers identified were lack of knowledge of pharmacological treatments (45.8%) and lack of access to smoking cessation resources (44.2%). Contrary to international studies, time and financial incentive were not commonly cited barriers to delivering smoking cessation interventions. CONCLUSIONS: This survey identifies a need for continuing education in smoking cessation practice. Dissemination of policies, guidelines and resources may assist OHPs to become more engaged and confident in delivering smoking cessation interventions as part of their routine practice.

Rapid isolation and high-throughput determination of cellulase and laminarinase activity in soils.

A new method for extracting soil enzymes is described and a microplate method for assaying soil beta-1,4-glucanases (cellulases) and beta-1,3-glucanases (laminarinases). Soil samples were mechanically disrupted to produce crude enzyme extracts, and diluted preps incubated in microplates containing either carboxymethyl cellulose (CMC) to determine cellulase activity or laminarin substrate to determine laminarinase activity. The resulting glucose was measured using the fluorometric Amplex Red glucose assay. The method was reproducible, could be completed in 1 day and measured twice as much enzyme activity than the standard passive soil enzyme extraction procedure. The method described herein facilitates the development of high-throughput soil multiplex enzymatic assays from several soil samples at one time, and is well suited to the study of functional microbial ecology.

Reliability of medial temporal lobe volume measurements using reformatted 3D images.

The study assessed whether standardizing the angle of image display and controlling for head position in three planes affects the scan-rescan reliability of medial temporal lobe volume measures when very thin (1.5 mm) slices are used. Five volunteers were scanned two times on consecutive days. A three-dimensional MRI sequence acquired whole brain data in 1.4 mm thick coronal slices. The data were displayed as 1.5 mm thick images and were rated both in the originally acquired coronal plane, and after reformatting to correct for head tilt and display the brain in the coronal plane perpendicular to the long axis of the left anterior hippocampus. One rater measured five brain regions (temporal lobe, anterior and posterior hippocampus, amygdala, and temporal horn) on the left and right sides of the two non-reformatted and two reformatted scans to obtain inter-scan variance. Furthermore, most scans were remeasured, to obtain 'reread' variances. All data were log-transformed in order to produce comparable variability across brain regions of different sizes. For all the regions, except the temporal horn, the non-reformatted scans showed significantly larger scan-rescan variability than the reformatted scans. A typical standard deviation for a non-reformatted pair of scans was 0.10, corresponding to 26% error, while a typical value for a reformatted pair of scans was 0.04, corresponding to 10% error. For all the regions, the reread data (intra-rater reliability) gave similar results for both reformatted and non-reformatted images with similar standard deviations (typical value for reread standard deviation was 0.020, corresponding to 5% error). The data suggest that, even when very thin slices are acquired, volume measurement accuracy of gray matter structures in the temporal lobe is considerably improved by controlling for image orientation in three planes. For these structures, the sample size needed to detect a small (5%) within-subject volume change would be halved if reformatted images were used. Image contrast is an additional important factor since the reformatted T1 weighted images used in this study, which have suboptimal CSF/brain contrast, worsened measurement accuracy in the temporal horn.

Two-dimensional parallel array technology as a new approach to automated combinatorial solid-phase organic synthesis

An automated, 96-well parallel array synthesizer for solid-phase organic synthesis has been designed and constructed. The instrument employs a unique reagent array delivery format, in which each reagent utilized has a dedicated plumbing system. An inert atmosphere is maintained during all phases of a synthesis, and temperature can be controlled via a thermal transfer plate which holds the injection molded reaction block. The reaction plate assembly slides in the X-axis direction, while eight nozzle blocks holding the reagent lines slide in the Y-axis direction, allowing for the extremely rapid delivery of any of 64 reagents to 96 wells. In addition, there are six banks of fixed nozzle blocks, which deliver the same reagent or solvent to eight wells at once, for a total of 72 possible reagents. The instrument is controlled by software which allows the straightforward programming of the synthesis of a larger number of compounds. This is accomplished by supplying a general synthetic procedure in the form of a command file, which calls upon certain reagents to be added to specific wells via lookup in a sequence file. The bottle position, flow rate, and concentration of each reagent is stored in a separate reagent table file. To demonstrate the utility of the parallel array synthesizer, a small combinatorial library of hydroxamic acids was prepared in high throughput mode for biological screening. Approximately 1300 compounds were prepared on a 10 µmole scale (3-5 mg) in a few weeks. The resulting crude compounds were generally >80% pure, and were utilized directly for high throughput screening in antibacterial assays. Several active wells were found, and the activity was verified by solution-phase synthesis of analytically pure material, indicating that the system described herein is an efficient means for the parallel synthesis of compounds for lead discovery. Copyright 1998 John Wiley & Sons, Inc.

Indirect assessment of callus fresh weight by non-destructive methods.

The size of callus of Nicotiana plumbaginifolia was measured by determinations of fresh weight (FW), area (electronic planimeter and a point-counting method) and width (standard width and greatest width). All these methods, with the exception of the standard width measurements, were found to produce adequate substitutes for fresh weight.Particular advantages apply to the use of the point-counting method, but the relationship between callus area and point interval was found to be critically important in determining the accuracy of measurements. The use of surface dimensions rather than FW permits continuous measurement of callus size without disturbance of the callus or its environment within the containers.

A rapid method of determining growth characteristics of plant cell populations in batch suspension culture.

A non-destructive, simple and accurate method of determining the relative growth rate (RGR) of the packed cell volume (PCV) of plant suspension cells in one Erlenmeyer flask at any time during the incubation period is described. The Erlenmeyer flask was tilted and the length of the chord formed by the surface of the packed cells across the bottom of the flask was measured. The chord length and the log PCV were correlated in a calibration line. The method enables the RGR during the exponential growth phase to be calculated by multiplying the slope of the linear part of the curve of the chord length in time with the slope of the calibration line. In order to investigate other growth parameters and to analyse the accuracy of the method statistically, a four-parameter function for the chord length and a computer program were used.The RGR during the exponential growth phase of cell suspensions of Solanum tuberosum and Haplopappus gracilis appeared to be independent of the PCV of the inoculum. The method appeared to be sufficiently accurate.

Two outbreaks of Flavobacterium meningosepticum type E in a neonatal intensive care unit.

Two separate outbreaks due to Flavobacterium meningosepticum type E occurred in a neonatal intensive care unit in March-April and July 1975. The first outbreak involved all five infants in the unit. Two infants developed meningitis, one had bacteremia, and two were colonized. During the second outbreak, five of seven infants were colonized but none developed disease. The upper respiratory tract was colonized first in most instances, and the organism persisted at this site for a mean of 17.3 days. Duration of colonization was more prolonged in infants receiving antibiotics than in untreated infants. Extensive environmental surveillance failed to demonstrate a reservoir, however, F. meningosepticum was recovered from three nasoendotracheal tubes and from an aerosol tube before colonization of four infants. The organism was resistant to most antimicrobial colonization of four infants. The organism was resistant to most antimicrobial agents tested and developed resistance to others during the treatment course of one infant. Although F. meningosepticum was not recovered from cultures of transport vehicles, several other gram-negative bacteria were isolated and were also resistant to multiple antibiotics.

Anaerobic infections in children: a prospective survey.

Over an 18-month period, cultures from 95 infants and children yielded 146 anaerobic organisms in 110 clinical specimens. Bacteroides was the most frequently isolated anaerobe, followed by Propionibacterium and Clostridium species. Intra-abdominal sources, soft tissues, and blood were the three major sources (82%) of isolation of anaerobes. Whereas most patients (58%) were over 5 years of age and only 11% were newborns, anaerobic infections constituted a rather uniform proportion of all infections, regardless of sources, in all age groups. Anaerobes accounted for only 2.9% of all positive cultures encountered from the various sources. Rates of recovery of anaerobes from intra-abdominal sources were significantly the highest, and from soft-tissue infections they were significantly the lowest. The anaerobic bacteremias observed were of no clinical significance when Propionibacterium species were isolated; however, recovery of other anaerobes from the blood, and primarily Bacteroides species, was usually associated with clinical disease. Except in blood cultures, anaerobes almost invariably coexisted with facultative bacteria.