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1.
NPJ Microgravity ; 9(1): 70, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37673938

RESUMO

X-ray radioscopy enables the in-situ monitoring of metal alloy processes and then gives access to crucial information on the dynamics of the underlying phenomena. In the last decade, the utilisation of this powerful imaging technique has been adapted to microgravity platforms such as sounding rockets and parabolic flights. The combination of microgravity experimentation with X-ray radioscopy has resulted in a leap in the understanding of fundamental science and has opened new paths in the fields of materials science. The present review focuses on the short history of this research, which includes facility developments, microgravity experiments and results obtained by partners of the XRMON (In-situ X-Ray MONitoring of advanced metallurgical processes under microgravity and terrestrial conditions) research project in the framework of the MAP (Microgravity Application Promotion) programme of the European Space Agency. Three illustrative research topics that were advanced significantly through the use of X-ray radioscopy will be detailed: solidification of metal alloys, metallic foam formation and diffusion in melts.

2.
Brain Spine ; 2: 100913, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36248176

RESUMO

•All patients with a Fisher grade 2 bleed and a negative CT angiogram had catheter angiography negative for any abnormality.•Neuroradiologists identified vascular abnormalities not reported by district general hospitals.•Follow-up MRI may be a useful adjunct in subarachnoid haemorrhage.

3.
S Afr J Sports Med ; 33(1): v33i1a9433, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-36816910

RESUMO

Background: Maximal strength is a key variable within youth rugby union and is therefore of merit when testing and monitoring youth rugby athletes. Isometric mid-thigh pull peak force (IMTP PF) has been observed to be a reliable, valid, and safe means of assessing maximal strength in previously researched cohorts. Currently, there exists a distinct lack of literature with regards to the use of IMTP PF with non-elite youth athletes. Objectives: (1) Investigate the intra-day reliability of the IMTP PF with respect to the three age-grades of Irish schoolboy rugby union, (2) investigate the inter-day reliability of the IMTP PF within Irish schoolboy rugby union. Methods: The current study utilised self-selected body positions of 84 non-elite schoolboy rugby union athletes (age: 14.7 ±1.7 years; height: 170.6 ±10.3 cm; mass: 63.9 ±14.8 kg). Results: IMTP PF was observed to be a reliable measure of peak force both inter- and intra-day (Intra-day: Coefficient of Variation 3.3%; Interclass Correlation Coefficient 0.99; 95% Confidence Interval 0.99 - 1.00; Inter-day: Coefficient of Variation = 5.1%; Interclass Correlation Coefficient 0.99; 95% Confidence Interval 0.98 - 1.00). A change of 10.9 kg should be deemed worthwhile when working with Irish schoolboy rugby players. Conclusion: The IMTP PF is a safe and reliable measure of maximal strength in non-elite youth rugby athletes.

4.
J Dent Res ; 100(5): 507-514, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33345672

RESUMO

Guidance intended to reduce fluoride toothpaste ingestion in early childhood was introduced in Ireland in 2002. In 2007, water fluoride concentration was adjusted from 0.8-1.0 to 0.6-0.8 ppm. The objective of this study was to determine the difference in caries and fluorosis levels following introduction of these 2 policy measures. A before-and-after study compared caries and fluorosis in random samples of 8-y-olds in Dublin (n = 707) and Cork-Kerry (n = 1148) in 2017 with 8-y-olds in Dublin (n = 679) and Cork-Kerry (n = 565) in 2002. Dentinal caries experience (primary teeth, d3vcmft(cde)) and fluorosis (permanent teeth, Dean's index of very mild or higher) were clinically measured. Lifetime exposure to community water fluoridation (CWF) was classified as "full CWF"/"no CWF." Effect of examination year on caries prevalence and severity and fluorosis prevalence was assessed using multivariate regression adjusting for other explanatory variables. There was little change in commencement of fluoride toothpaste use at ≤24 mo following introduction of toothbrushing guidance. Among children with full CWF, there was no statistically significant difference in caries prevalence or severity between 2017 and 2002. In 2017, caries prevalence was 55% in Dublin (full CWF) and 56% in Cork-Kerry (full CWF), and mean d3vcmft(cde) among children with caries was 3.4 and 3.7, respectively. Caries severity was less in 2017 (mean 4.2) than 2002 (mean 4.9) among children with no CWF (P = 0.039). The difference in caries severity between children with full CWF and no CWF was less in 2017 than in 2002 (interaction P = 0.013), suggesting a reduced benefit for CWF in 2017. In 2017, fluorosis prevalence was 18% in Dublin (full CWF) and 12% in Cork-Kerry (full CWF). Fluorosis was predominantly "very mild" with no statistically significant difference between 2017 and 2002. CWF at 0.6 to 0.8 ppm is an effective caries-preventive measure. Results suggested low uptake of toothbrushing guidance, a reduced caries-preventive effect for CWF in primary teeth, and no reduction in fluorosis following introduction of the policy measures.


Assuntos
Cárie Dentária , Fluorose Dentária , Criança , Pré-Escolar , Cárie Dentária/epidemiologia , Cárie Dentária/prevenção & controle , Fluoretação , Fluoretos , Fluorose Dentária/epidemiologia , Fluorose Dentária/prevenção & controle , Humanos , Prevalência , Água
5.
J Phys Condens Matter ; 33(3)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33078715

RESUMO

The layered transition-metal dichalcogenide PdTe2has been discovered to possess bulk Dirac points as well as topological surface states. By measuring the magnetization (up to 7 T) and magnetic torque (up to 35 T) in single crystalline PdTe2, we observe distinct de Haas-van Alphen (dHvA) oscillations. Eight frequencies are identified withH||c, with two low frequencies (Fα= 8 T andFß= 117 T) dominating the spectrum. The effective masses obtained by fitting the Lifshitz-Kosevich (LK) equation to the data aremα*=0.059m0andmß*=0.067m0wherem0is the free electron mass. The corresponding Landau fan diagrams allow the determination of the Berry phase for these oscillations resulting in values of ∼0.67πfor the 3D α band (hole-type) (down to the 1st Landau level) and ∼0.23π-0.73πfor the 3D ß band (electron-type) (down to the 3rd Landau level). By investigating the angular dependence of the dHvA oscillations, we find that the frequencies and the corresponding Berry phase (ΦB) vary with the field direction, with a ΦB∼ 0 whenHis 10°-30° away from theabplane for both α and ß bands. The multiple band nature of PdTe2is further confirmed from Hall effect measurements.

6.
Radiography (Lond) ; 26 Suppl 2: S94-S99, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32291123

RESUMO

INTRODUCTION: With the introduction of digital radiography, the feedback between image quality and over-exposure has been partly lost which in some cases has led to a steady increase in dose. Over the years the introduction of exposure index (EI) has been used to resolve this phenomenon referred to as 'dose creep'. Even though EI is often vendor specific it is always a related of the radiation exposure to the detector. Due to the nature of this relationship EI can also be used as a patient dose indicator, however this is not widely investigated in literature. METHODS: A total of 420 dose-area-product (DAP) and EI measurements were taken whilst varying kVp, mAs and body habitus on two different anthropomorphic phantoms (pelvis and chest). Using linear regression, the correlation between EI and DAP were examined. Additionally, two separate region of interest (ROI) placements/per phantom where examined in order to research any effect on EI. RESULTS: When dividing the data into subsets, a strong correlation between EI and DAP was shown with all R-squared values > 0.987. Comparison between the ROI placements showed a significant difference between EIs for both placements. CONCLUSION: This research shows a clear relationship between EI and radiation dose which is dependent on a wide variety of factors such as ROI placement, body habitus. In addition, pathology and manufacturer specific EI's are likely to be of influence as well. IMPLICATIONS FOR PRACTICE: The combination of DAP and EI might be used as a patient dose indicator. However, the influencing factors as mentioned in the conclusion should be considered and examined before implementation.


Assuntos
Doses de Radiação , Exposição à Radiação , Intensificação de Imagem Radiográfica , Humanos , Imagens de Fantasmas , Reprodutibilidade dos Testes
12.
Food Chem Toxicol ; 115 Suppl 1: S206-S213, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29408617

RESUMO

The use of this material under current conditions is supported by existing information. The material (dihydro-ß-terpinyl acetate) was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data from the read across analog menthyl acetate (1α,2ß,5α) (CAS # 89-48-5) show that dihydro-ß- terpinyl acetate is not genotoxic nor does it have skin sensitization potential. The repeated dose, reproductive and local respiratory toxicity endpoints were completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class I material (0.03, 0.03 mg/kg/day and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoint was completed based on UV spectra. The environmental endpoints were evaluated, dihydro-ß-terpinyl acetate was found not to be PBT as per the IFRA Environmental Standards and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC) are <1.


Assuntos
Odorantes , Terpenos/toxicidade , Testes de Toxicidade/métodos , Monoterpenos Cicloexânicos , Dermatite Fototóxica , Ecotoxicologia , Humanos , Pulmão/efeitos dos fármacos , Nível de Efeito Adverso não Observado , Reprodução/efeitos dos fármacos , Medição de Risco , Segurança , Pele/efeitos dos fármacos , Teratógenos/toxicidade
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