1,210 research outputs found
The importance of screening in children who snore
It is important to screen for OSAS in children who snore, as early treatment of OSAS can prevent neurocognitive, behavioural, cardiovascular and metabolic consequences. Paediatricians should always investigate sleep habits and the possible presence of snoring, respiratory efforts or pauses during routine examination of children. These instruments may be effectively used to identify patients with OSAS, and the specificity and positive predictive value may be increased by adding other screening instruments such as nocturnal pulse oximetry [10]. The sleep questionnaires are instruments that can be used to screen patient candidates for a PSG study for suspected OSAS, and to identify those with a mild form of SDB, enabling early treatment
Life cycle assessment of nanocellulose-reinforced advanced fibre composites
The research and development of nanocellulose-reinforced polymer composites have dramatically increased in the recent years due to the possibility of exploiting the high tensile stiffness and strength of nanocellulose. In the work, the environmental impacts of bacterial cellulose (BC)- and nanofibrillated cellulose (NFC)-reinforced epoxy composites were evaluated using life cycle assessment (LCA). Neat polylactide (PLA) and 30% randomly oriented glass fibre-reinforced polypropylene (GF/PP) composites were used as benchmark materials for comparison. Our cradle-to-gate LCA showed that BC- and NFC-reinforced epoxy composites have higher global warming potential (GWP) and abiotic depletion potential of fossil fuels (ADf) compared to neat PLA and GF/PP even though the specific tensile moduli of the nanocellulose-reinforced epoxy composites were higher than neat PLA and GF/PP. However, when the use phase and the end-of-life of nanocellulose-reinforced epoxy composites were considered, the “green credentials” of nanocellulose-reinforced epoxy composites were comparable to that of neat PLA and GF/PP composites. Our life cycle scenario analysis showed that the cradle-to-grave GWP and ADf of BC- and NFC-reinforced epoxy composites could be lower than neat PLA when the composites contains more than 60 vol.-% nanocellulose. Our LCA model suggests that nanocellulose-reinforced epoxy composites with high nanocellulose loading is desired to produce materials with “greener credentials” than the best performing commercially available bio-derived polymer
Superparamagnetic behaviour of antiferromagnetic DyPO4 nanoparticles
We report on the low-temperature magnetic ac-susceptibility of
antiferromagnetic DyPO4 nanoparticles with a very high surface to volume ratio.
The results are interpreted in terms of superparamagnetic relaxation of the
Neel vector arising from a relatively large number approx 0.2 Na of
uncompensated spins probably existing on the surface of the nanoparticles. The
activation energy of the relaxation process is found to be Ea / kB = (2.6+-0.1)
K within a model taking into account the magnetic interaction between
nanoparticles.Comment: 3 pages, 1 figure, Espcrc2, ICM0
Spin-enhanced magnetocaloric effect in molecular nanomagnets
An unusually large magnetocaloric effect for the temperature region below 10 K is found for the Fe-14 molecular nanomagnet. This is to large extent caused by its extremely large spin S ground state combined with an excess of entropy arising from the presence of low-lying excited S states. We also show that the highly symmetric Fe-14 cluster core, resulting in small cluster magnetic anisotropy, enables the occurrence of long-range antiferromagnetic order below T-N=1.87 K
Magnetocaloric effect in hexacyanochromate Prussian blue analogs
We report on the magnetocaloric properties of two molecule-based
hexacyanochromate Prussian blue analogs, nominally CsNi[Cr(CN)_6](H_2O) and
Cr_3[Cr(CN)_6]_2x12(H_2O). The former orders ferromagnetically below Tc=90 K,
whereas the latter is a ferrimagnet below Tc=230 K. For both, we find
significantly large magnetic entropy changes DSm associated to the magnetic
phase transitions. Notably, our studies represent the first attempt to look at
molecule-based materials in terms of the magnetocaloric effect for temperatures
well above the liquid helium range.Comment: 4 pages, 6 figure
Magnetothermal properties of molecule-based materials
We critically review recent results obtained by studying the low-temperature
specific heat of some of the most popular molecular magnets. Perspectives of
this field are discussed as well.Comment: 12 pages text + 14 pages figures, Submitted as "feature article" to
Journal of Materials Chemistr
Unexpected death of a ventilator-dependent amyotrophic lateral sclerosis patient
Background: Amyotrophic lateral sclerosis (ALS) is a fatal, progressive, neurodegenerative disease and most patients affected die of respiratory compromise and/or pneumonia within 2â3 years of diagnosis. As ALS progresses, ventilator assistance is required. In the end stages of the disease, patients suffer from respiratory failure and may become ventilator-dependent. Deaths due to malfunction of mechanical ventilators are reported but there are very few forensic autopsy records. We report the case of a 69-year-old ALS female ventilator-dependent, trachostomised patient who was found dead by her husband, with the ventilator in âstand-byâ mode. Method: A forensic autopsy was performed. Samples of internal organs were taken for histological and toxicological examination. The ventilator internal memory was also analysed and tested in order to find possible malfunction. Results: Gross examination did not reveal any sign of trauma but showed brain and lung congestion. Pulmonary histological examination revealed thickening of peribronchial interstitial space, alveolar over-distension, break of inter-alveolar walls and diffuse alveolar haemorrhages. Focal microhemorrhages were also detected in other organs. Analysis of the ventilator internal memory showed that during the night of death, there had been several voltage drops. Specific tests revealed malfunction of the internal battery which was unable to provide the necessary voltage, as a consequence the ventilator switched off, stopping ventilation. Battery malfunction reduced the volume of the ventilator alarm, which was not heard by the caregiver. Conclusion: Histological pattern, with acute pulmonary emphysema and focal polivisceral haemorrhages, is strongly suggestive of a death due to âacuteâ asphyxia. The authors also discuss the need for strict supervision and follow up of these ventilatory dependent patients and their devices. Resumo: Introdução: A Esclerose Lateral Amiotrófica (ELA) é uma doença fatal, progressiva e neurodegenerativa e a maioria dos doentes afectados morrerão de falha respiratória e/ou pneumonia 2 ou 3 anos após o diagnóstico. à medida que a ELA progride torna-se necessária a assistência ventilatória. Nos estágios finais da doença, os doentes sofrem de insuficiência respiratória e podem tornar-se dependentes do ventilador. São conhecidas mortes devido ao mau funcionamento de ventiladores mecânicos mas existem poucos registos forenses de tal situação. Relatamos o caso de uma doente de 69 anos com ELA, traqueostomizada e dependente do ventilador, que foi encontrada morta pelo seu marido com o ventilador em modo de espera («stand-by»). Método: Foi realizada uma autópsia forense. Foram recolhidas amostras dos órgãos internos para exame toxicológico e histológico. A memória interna do ventilador foi também analisada e testada de modo a descobrir uma possÃvel avaria. Resultados: O exame macroscópico não revelou qualquer sinal de trauma mas indicou congestão cerebral e pulmonar. O exame pulmonar histológico revelou o espessamento do espaço intersticial peribrônquico, sobredistensão alveolar, quebra de paredes interalveolares e hemorragias alveolares difusas. Foram detetadas micro-hemorragias focais noutros órgãos. A análise da memória interna do ventilador mostrou que, durante a noite da morte, houve diversas quedas de tensão. Testes especÃficos revelaram o mau funcionamento da bateria interna que não conseguiu fornecer a tensão necessária, consequentemente o ventilador desligou-se, parando a ventilação. O mau funcionamento da bateria reduziu o volume do alarme do ventilador, que não foi ouvido pelo prestador de cuidados. Conclusão: O padrão histológico, com enfisema pulmonar agudo e hemorragias focais poliviscerais, é fortemente indicador de morte devido a asfixia «aguda». Os autores discutem também a necessidade de uma supervisão rigorosa e seguimento destes doentes dependentes do ventilador e dos seus equipamentos. Keywords: Amyotrophic lateral sclerosis, Acute respiratory failure, Home mechanical ventilation, Palavras-chave: Esclerose lateral amiotrófica, Insuficiência respiratória aguda, Ventilação mecânica doméstic
Large adiabatic temperature and magnetic entropy changes in EuTiO3
We have investigated the magnetocaloric effect in single and polycrystalline
samples of quantum paraelectric EuTiO3 by magnetization and heat capacity
measurements. Single crystalline EuTiO3 shows antiferromagnetic ordering due to
Eu2+ magnetic moments below TN = 5.6 K. This compound shows a giant
magnetocaloric effect around its Neel temperature. The isothermal magnetic
entropy change is 49 Jkg-1K-1, the adiabatic temperature change is 21 K and the
refrigeration capacity is 500 JKg-1 for a field change of 7 T at TN. The single
crystal and polycrystalline samples show similar values of the magnetic entropy
change and adiabatic temperature changes. The large magnetocaloric effect is
due to suppression of the spin entropy associated with localized 4f moment of
Eu2+ ions. The giant magnetocaloric effect together with negligible hysteresis,
suggest that EuTiO3 could be a potential material for magnetic refrigeration
below 20 K.Comment: 12 pages, 4 figure
Simplified approach to integrate seismic retrofitting prioritization with social cost evaluation: A case study in central Italy
In the last three decades, bridge stock seismic retrofitting prioritization has become one of the cult topics for scientific discussions in the bridge management strategies. More recent methods are focusing on the evaluation of the generalized failure cost, of a specific bridge derived from direct and indirect costs induced to the users/residents of the area exposed to the seismic hazard as a consequence of bridge collapse. However, when these approaches have to be applied to large transport networks, appear still very complex and computa-tional demanding, and therefore simplified methods to evaluate the impact in terms of social cost related to the reduced efficiency of a transportation network due to potential bridge failure, are required.In this work, a simplified method for seismic retrofitting prioritization on a bridge stock is proposed, which is based on a "blended" approach considering specific fragility curves according to several bridge features and condition state, seismic inputs and generalized failure costs related to the transportation network. The effectiveness of the method has been showed on a case study of a local bridge stock placed in central Italy and the obtained results have been compared with those provided by more refined transport simulation models, on one hand, and by more traditional prioritization approaches, on the other. It is highlighted that this method can be very useful for transportation network managers with in a limited budget scenario, in case of lack of information about possible earthquake -induced impacts on a transportation network efficiency.(c) 2022 Periodical Offices of Chang'an University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
DIGITAL TECHNOLOGIES IN COMPLETE REMOVABLE DENTURE: A CASE SERIES
Aim: complete removable denture has been the last prosthetic
procedure to follow the digitization because of drawbacks into
the intraoral scans of edentulous arches; in addition, it is impossible
to record muco-compressive impressions through
IOS. So, a full digital procedure is not yet conceivable.
We considered the possibility of an “hybrid” protocol thanks to
a specific software. The hybrid protocol requires traditional
techniques for the anatomical impression followed by laboratory
scan of casts and wax.
Methods: the software consists in two synergic programs:
- Ruthinium Digital Preview allows to have a picture of the prosthetic
project and change it previously, thanks to two calibrated
photographs.
- Ruthinium Denture Guide is a 3D software that helps laboratory
work into denture production, particularly to a correct setting of
acrylic teeth. The planned dental setting is printed in a template.
Template and base plate, both 3D printed, are connected thanks
to a structure that ensures the designed occlusal scheme.
Results: the collected clinical cases did not allow a statistic
analysis about patient and clinical satisfaction through evaluation
questionnaires.
Conclusion: it looks like that patients appreciate the prosthetic
rehabilitation previsualization and in particular being actively
involved in aesthetic choices. Clinically, it appears to be a
shorter need for touch-ups at the last appointment; probably
because of the 3D tooth position planning
- …