289 research outputs found
Productivity Enhancement in Directed Energy Deposition: The Oscillating Scanning Strategy Approach
Directed Energy Deposition (DED) is an additive manufacturing process that enables the production of large metal components by melting the feedstock material while being deposited. An improvement of the production speed of this process would further increase its applicability in many industrial fields. The DED building rate is strictly related to the building parameters adopted, in particular to the laser spot diameter, which also affects the build accuracy and the surface quality of the components. The possibility of using a variable laser spot would result in a significant increase in the production rate in bulky zones, while also providing a good surface quality where needed. In the present work, an oscillating scanning strategy was used to create a large apparent laser spot (+ 170% of the nominal value) to produce 316L stainless steel samples via DED. The optimisation of the DED parameters with the oscillating strategy was performed using the single scan tracks (SSTs) approach. The morphologies of the SSTs obtained with different process parameters were assessed and the geometrical features related to the melt pools were analysed in order to select the most suitable X and Z displacements for the production of the cubic samples. The analyses of the cubes revealed that, if the correct overlap among nearby scans is selected, it is possible to obtain dense samples with all the oscillating diameters tested. Finally, comparing the building rate and powder efficiency values confirmed that this method can accelerate the building process and improve its overall performance
Effectiveness of an innovative sensory approach to improve childrenâs nutritional choices
A case-control study was conducted to investigate the effectiveness of the EdueatÂź Method, through experiential workshops focused on the use of all 5 senses. In two different primary schools in the same city, questionnaires were administered in two months with a follow-up one year later. Participants: 119 children (age 8.2â9.0) chosen randomly; control group 66 (55.5%). Seven lessons of 2 h each were held in the schools by experts of the EdueatÂź method and seven extra lessons by the teachers. The main outcome measures were the childrenâs changes in their approach and attitude towards their eating habits. The answers were grouped with factor analysis and summarized through scores. Repeated-measures analysis of variance was conducted in order to identify the relationships between scores and treatment over time. At the end of treatment, the intervention group showed a significant appreciation towards healthy foods (+4.15 vs. â0.05, p = 0.02) and a greater capacity in identifying foods which are very good for the health (+15.6 vs. +14.4, p = 0.02). In conclusion, the EdueatÂź method was found to be particularly promising in transmitting knowledge of those foods which are healthy. Greater involvement of teachers and parents is crucial
The effect of monovalent (Na+, K+) and divalent (Ca2+, Mg2+) cations on rapeseed oleosome (oil body) extraction and stability at pH 7
Oleosomes are storage vehicles of TAGs in plant seeds. They are protected with a phospholipid-protein monolayer and extracted with alkaline aqueous media; however, pH adjustment intensifies the extraction process. Therefore the aim of this work was to investigate the extraction mechanism of rapeseed oleosomes at pH 7 and at the presence of monovalent and divalent cations (Na+, K+, Mg2+, and Ca+2). The oleosome yield at pH 9.5 was 64 wt%, while the yield at pH 7 with H2O was just 43 wt%. The presence of cations at pH 7, significantly enhanced the yield, with K+ giving the highest yield (64 wt%). The cations affected the oleosome interface and their interactions. The presence of monovalent cations resulted in aggregation and minor coalescence, while divalent cations resulted in extensive coalescence. These results help to understand the interactions of oleosomes in their native matrix and design simple extraction processes at neutral conditions
Economic impact of remote monitoring on ordinary follow-up of implantable cardioverter defibrillators as compared with conventional in-hospital visits: a single-center prospective and randomized study
Few data are available on actual follow-up
costs of remote monitoring (RM) of implantable defibrillators
(ICD). Our study aimed at assessing current direct costs
of 1-year ICD follow-up based on RM compared with
conventional quarterly in-hospital follow-ups.
Methods and results Patients (N=233) with indications for
ICD were consecutively recruited and randomized at implant
to be followed up for 1 year with standard quarterly inhospital
visits or by RM with one in-hospital visit at 12
months, unless additional in-hospital visits were required
due to specific patient conditions or RM alarms. Costs were
calculated distinguishing between provider and patient
costs, excluding RM device and service cost. The frequency
of scheduled in-hospital visits was lower in the RM group
than in the control arm. Follow-up required 47 min per
patient/year in the RM arm versus 86 min in the control
arm (p=0.03) for involved physicians, generating cost estimates
for the provider of USD 45 and USD 83 per patient/-
year, respectively. Costs for nurses were comparable.
Overall, the costs associated with RM and standard
follow-up were USD 103±27 and 154±21 per patient/year,
respectively (p=0.01). RM was cost-saving for the patients:
USD 97±121 per patient/year in the RM group versus 287±
160 per patient/year (p=0.0001).
Conclusion The time spent by the hospital staff was significantly
reduced in the RM group. If the costs for the device
and service are not charged to patients or the provider,
patients could save about USD 190 per patient/year while
the hospital could save USD 51 per patient/year
Virtual reality for the assessment of everyday cognitive functions in older adults: an evaluation of the virtual reality action test and two interaction devices in a 91-year-old woman
Performance-based functional tests for the evaluation of daily living activities demonstrate strong psychometric properties and solve many of the limitations associated with self- and informant-report questionnaires. Virtual reality (VR) technology, which has gained interest as an effective medium for administering interventions in the context of healthcare, has the potential to minimize the time-demands associated with the administration and scoring of performance-based assessments. To date, efforts to develop VR systems for assessment of everyday function in older adults generally have relied on non-immersive systems. The aim of the present study was to evaluate the feasibility of an immersive VR environment for the assessment of everyday function in older adults. We present a detailed case report of an elderly woman who performed an everyday activity in an immersive VR context (Virtual Reality Action Test) with two different types of interaction devices (controller vs. sensor). VR performance was compared to performance of the same task with real objects outside of the VR system (Real Action Test). Comparisons were made on several dimensions, including (1) quality of task performance (e.g., order of task steps, errors, use and speed of hand movements); (2) subjective impression (e.g., attitudes), and (3) physiological markers of stress. Subjective impressions of performance with the different controllers also were compared for presence, cybersickness, and usability. Results showed that the participant was capable of using controllers and sensors to manipulate objects in a purposeful and goal-directed manner in the immersive VR paradigm. She performed the everyday task similarly across all conditions. She reported no cybersickness and even indicated that interactions in the VR environment were pleasant and relaxing. Thus, immersive VR is a feasible approach for function assessment even with older adults who might have very limited computer experience, no prior VR exposure, average educational experiences, and mild cognitive difficulties. Because of inherent limitations of single case reports (e.g., unknown generalizability, potential practice effects, etc.), group studies are needed to establish the full psychometric properties of the Virtual Reality Action Test
Histone Acetylation Defects in Brain Precursor Cells: A Potential Pathogenic Mechanism Causing Proliferation and Differentiation Dysfunctions in Mitochondrial Aspartate-Glutamate Carrier Isoform 1 Deficiency
Mitochondrial aspartate-glutamate carrier isoform 1 (AGC1) deficiency is an ultra-rare genetic disease characterized by global hypomyelination and brain atrophy, caused by mutations in the SLC25A12 gene leading to a reduction in AGC1 activity. In both neuronal precursor cells and oligodendrocytes precursor cells (NPCs and OPCs), the AGC1 determines reduced proliferation with an accelerated differentiation of OPCs, both associated with gene expression dysregulation. Epigenetic regulation of gene expression through histone acetylation plays a crucial role in the proliferation/differentiation of both NPCs and OPCs and is modulated by mitochondrial metabolism. In AGC1 deficiency models, both OPCs and NPCs show an altered expression of transcription factors involved in the proliferation/differentiation of brain precursor cells (BPCs) as well as a reduction in histone acetylation with a parallel alteration in the expression and activity of histone acetyltransferases (HATs) and histone deacetylases (HDACs). In this study, histone acetylation dysfunctions have been dissected in in vitro models of AGC1 deficiency OPCs (Oli-Neu cells) and NPCs (neurospheres), in physiological conditions and following pharmacological treatments. The inhibition of HATs by curcumin arrests the proliferation of OPCs leading to their differentiation, while the inhibition of HDACs by suberanilohydroxamic acid (SAHA) has only a limited effect on proliferation, but it significantly stimulates the differentiation of OPCs. In NPCs, both treatments determine an alteration in the commitment toward glial cells. These data contribute to clarifying the molecular and epigenetic mechanisms regulating the proliferation/differentiation of OPCs and NPCs. This will help to identify potential targets for new therapeutic approaches that are able to increase the OPCs pool and to sustain their differentiation toward oligodendrocytes and to myelination/remyelination processes in AGC1 deficiency, as well as in other white matter neuropathologies
Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence
Background
The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo.
Findings
In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%).
Conclusions
This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms
Soil and water bioengineering: practice and research needs for reconciling natural hazard control and ecological restoration
Soil and water bioengineering is a technology that encourages scientists and practitioners to combine their knowledge and skills in the management of ecosystems with a common goal to maximize benefits to both man and the natural environment. It involves techniques that use plants as living building materials, for: (i) natural hazard control (e.g., soil erosion, torrential floods and landslides) and (ii) ecological restoration or nature-based re-introduction of species on degraded lands, river embankments, and disturbed environments. For a bioengineering project to be successful, engineers are required to highlight all the potential benefits and ecosystem services by documenting the technical, ecological, economic and social values. The novel approaches used by bioengineers raise questions for researchers and necessitate innovation from practitioners to design bioengineering concepts and techniques. Our objective in this paper, therefore, is to highlight the practice and research needs in soil and water bioengineering for reconciling natural hazard control and ecological restoration. Firstly, we review the definition and development of bioengineering technology, while stressing issues concerning the design, implementation, and monitoring of bioengineering actions. Secondly, we highlight the need to reconcile natural hazard control and ecological restoration by posing novel practice and research questions
- âŠ