Naresuan University Journal
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Description and evaluation of a novel service for difficult to manage psychiatric in-patients
No full textPurpose – A new service was developed to provide transitional care between acute and secure services for people with serious mental illness who are considered “difficult to manage”. The purpose of this paper is to evaluate the work of the service by examining referrals made, strategies employed for each referral, and patient outcomes, as well as investigating issues in the service's development and implementation. Design/methodology/approach – A retrospective descriptive study by review of 38 case notes, and qualitative interviews of 47 staff within the service and those referring to the service. Findings – In the first eight months, 38 patients were referred due to violence, aggression and management problems. Most interventions provided by the service involved working with referring staff, rather than direct patient contact. Subsequently, 16 per cent required referral to higher levels of security. Interviews showed the team's aims needed to be more clearly established, but that ward staff found the service to be a useful and productive resource. Research limitations/implications – The study is descriptive and retrospective, but showed that the service provided appropriate interventions for managing patients with serious mental illness and challenging behaviour. Practical implications – A transitional service may have value in keeping patients in the least restrictive setting. Careful planning is needed in designing novel interventions, ensuring clear aims and effective management. Originality/value – The service under study was novel, and may be useful in facilitating successful transfer from, or preventing admission to, secure services
Memory formation shaped by astroglia
No full textAstrocytes, the most heterogeneous glial cells in the central nervous system, execute a multitude of homeostatic functions and contribute to memory formation. Consolidation of synaptic and systemic memory is a prolonged process and hours are required to form long-term memory. In the past, neurons or their parts have been considered to be the exclusive cellular sites of these processes, however, it has now become evident that astrocytes provide an important and essential contribution to memory formation. Astrocytes participate in the morphological remodeling associated with synaptic plasticity, an energy-demanding process that requires mobilization of glycogen, which, in the central nervous system, is almost exclusively stored in astrocytes. Synaptic remodeling also involves bidirectional astroglial-neuronal communication supported by astroglial receptors and release of gliosignaling molecules. Astroglia exhibit cytoplasmic excitability that engages second messengers, such as Ca2+, for phasic, and cAMP, for tonic signal coordination with neuronal processes. The detection of signals by astrocytes and the release of gliosignaling molecules, in particular by vesicle-based mechanisms, occurs with a significant delay after stimulation, orders of magnitude longer than that present in stimulus–secretion coupling in neurons. These particular arrangements position astrocytes as integrators ideally tuned to support time-dependent memory formation
Retrofit of heat-integrated crude oil distillation columns
No full textEngineering projects to increase the capacity of existing heat-integrated crude oil distillation columns are commonplace. Retrofit projects aim to exploit the processing capacity of existing units by changing operating parameters and/or modifying equipment. Operational modifications can be effective and usually incur little capital expenditure, but equipment changes may also be needed to achieve retrofit objectives. Existing retrofit methodologies for crude oil distillation systems mainly focus on increasing heat recovery, increasing crude oil throughput and/or increasing the yield of most valuable products by optimising column operating parameters. However, methodologies that also consider hardware modifications are lacking. The present work proposes a systematic retrofit methodology based on distillation column and heat exchanger network (HEN) simulation. Hydraulic correlations are used to consider replacing existing distillation column internals with high-capacity trays and/or structured packings. Industrially relevant case studies illustrate the benefits of the proposed methodology to analyse and assess hardware modifications for the retrofit of distillation systems when increasing capacity
Numerical Investigation of Rotation Effects on Anti-vortex Film-Cooling Holes
No full textThe anti-vortex film-cooling technique under rotating conditions is investigated using large eddy simulation (LES) due to its complex mixture between the main stream flow, film-cooling flow, and the flow through the anti-vortex holes. The film-cooling was enhanced by placing two small injection holes (anti-vortex holes) just downstream of the main cooling hole in order to modify the approaching boundary layer flow and its inter- action with the film-cooling jet. A geometry of a single row of rectangular holes inclined normally on a flat plate is used as the baseline case. The finite volume method and the unsteady SIMPLE algorithm were applied on a non-uniform staggered grid. The simulations were performed for four different values of rotation number (Ro) of 0.0, 0.03021,0.06042, and 0.12084 and a jet Reynolds number of 4,700. Three different values of velocity ratio (coolant jets / main jet velocity), namely 0.5, 1, and 1.5, were studied. One position of the anti-vortex holes is investigated with density ratio (coolant density / main stream density), namely 1.04. The present simulation is carried out using an in-house FORTRAN code. Numerical calculations of flow field and film-cooling effectiveness are validated with reported LES results. It was shown that the rotational speed is the dominant factor in deter- mining the cooling effectiveness level. The jet footprint of the anti-vortex is broader than for the single jet case and increases as Ro increases. Furthermore, it was also found that the anti-vortex technique used in this study reduces the mixing of the main stream and the coolant jets and improves the film-cooling effectiveness using the same amount of coolant fluid as was used in the case of a single jet. It was also shown that the anti-vortex holes create reverse vortices against the main vortices that are created by the main hole. These reverse vortices help to keep the coolant jet flow near the wall.<br/
Post-irradiation hardness development, chemical softening, and thermal stability of bulk-fill and conventional resin-composites
No full textObjectives To measure bottom/top hardness ratio of bulk-fill and conventional resin-composite materials, and to assess hardness changes after dry and ethanol storage. Filler content and kinetics of thermal decomposition were also tested using thermogravimetric analysis (TGA). Methods Six bulk-fill (SureFil SDR, Venus bulk fill, X-tra base, Filtek bulk fill flowable, Sonic fill, and Tetric EvoCeram bulk-fill) and eight conventional resin-composite materials (Grandioso flow, Venus Diamond flow, X-flow, Filtek Supreme Ultra Flowable, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested (n = 5). Initial and 24 h (post-cure dry storage) top and bottom microhardness values were measured. Microhardness was re-measured after the samples were stored in 75% ethanol/water solution. Thermal decomposition and filler content were assessed by TGA. Results were analysed using one-way ANOVA and paired sample t-test (α = 0.05). Results All materials showed significant increase of microhardness after 24 h of dry storage which ranged from 100.1% to 9.1%. Bottom/top microhardness ratio >0.9 was exhibited by all materials. All materials showed significant decrease of microhardness after 24 h of storage in 75% ethanol/water which ranged from 14.5% to 74.2%. The extent of post-irradiation hardness development was positively correlated to the extent of ethanol softening (R2 = 0.89, p <0.001). Initial thermal decomposition temperature assessed by TGA was variable and was correlated to ethanol softening. Conclusions Bulk-fill resin-composites exhibit comparable bottom/top hardness ratio to conventional materials at recommended manufacturer thickness. Hardness was affected to a variable extent by storage with variable inorganic filler content and initial thermal decomposition shown by TGA. Clinical significance The manufacturer recommended depth of cure of bulk-fill resin-composites can be reached based on the microhardness method. Characterization of the primary polymer network of a resin-composite material should be considered when evaluating its stability in the aqueous oral environment
Association analysis identifies new risk loci for congenital heart disease in Chinese populations.
No full textOur previous genome-wide association study (GWAS) identified two susceptibility loci for congenital heart disease (CHD) in Han Chinese. Here we identify additional loci by testing promising associations in an extended 3-stage validation consisting of 6,053 CHD cases and 7,410 controls. We find GW significant (
Prediction of implant loss and marginal bone loss by analysis of dental panoramic radiographs
No full textPurpose: One of the major factors governing implant success is the quantity and density of the host bone. The aim of this work was to determine whether mandibular bone texture features and cortical width measurements on plain radiographs could be associated with implant failure and/or marginal bone loss. Material and Methods: A statistical model was built to predict implant failure; it incorporated several radiographic features of cortical and cancellous bone texture, cortical width and patient smoking habits. Cortical width measurements and texture measurements of cortical and cancellous bone were made on the panoramic radiographs of 460 subjects. These were used to predict implant failure and marginal bone loss after 5 years. Receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC) were used to determine the diagnostic accuracy of the variables in predicting implant failure and marginal bone loss. Additionally, for 91 of 460 subjects with periapical radiographs, marginal bone levels around implants were measured over a 5 year period. Results: Of the 460 patients assessed for implant failure, 29 had failed implants (93.7% success rate). The ROC curve, built from this model had a sensitivity of 62.1% and specificity of 67.5%. The area under the curve (AUC) from the model was 0.690 (95% confidence interval [CI] 0.597 to 0.783). A model was also built to predict marginal bone loss. The ROC curve had 78.6% sensitivity and 74.6% specificity (AUC = 0.880, 95% CI = 0.810 to 0.953). Mandibular cortical width was not a significant predictor variable of either implant failure or bone loss. Conclusion: In a retrospective analysis 5 years after implant placement, features of cancellous and cortical bone of the mandible were significant in predicting implant failure and marginal bone loss in a sample of 460 patients
