Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Appl Radiat Isot ; 141: 288-291, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30122471

RESUMO

Patient radiation dose and image quality are primary issues in the conduct of nuclear medicine (NM) procedures. A range of protocols are currently used in image acquisition and analysis of quality control (QC) tests, with National Electrical Manufacturers Association (NEMA) methods and protocols widely accepted in providing an accurate description, measurement and report of γ-camera performance parameters. However, no standard software is available for image analysis. Present study compares vendor QC software analysis and three types of software freely downloadable from the internet: NMQC, NM Toolkit and ImageJ-NM Toolkit software. These were used for image analysis of QC tests of γ-cameras based on NEMA protocols including non-uniformity evaluation. Ten non-uniformity QC images were obtained using a dual head γ-camera installed in Trieste General Hospital and then analyzed. Excel analysis was used as the baseline calculation for the non-uniformity test according to NEMA procedures. The results of non-uniformity analysis showed good agreement between the independent types of software and Excel calculations (the average differences were 0.3%, 2.9%, 1.3% and 1.6% for the Useful Field of View (UFOV) integral, UFOV differential, Central Field of View (CFOV) integral and CFOV differential, respectively), while significant differences were detected following analysis using the company QC software when compared with Excel analysis (the average differences were 14.6%, 20.7%, 25.7% and 31.9% for the UFOV integral, UFOV differential, CFOV integral and CFOV differential, respectively). Compared to use of Excel calculations use of NMQC software was found to be in close accord. Variation in results obtained using the three types of software and γ-camera QC software was due to the use of different pixel sizes. It is important to conduct independent analyses tests in addition to using the vendor QC software in order to determine the differences between values.


Assuntos
Câmaras gama/normas , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/normas , Câmaras gama/estatística & dados numéricos , Humanos , Controle de Qualidade , Interpretação de Imagem Radiográfica Assistida por Computador/normas , Interpretação de Imagem Radiográfica Assistida por Computador/estatística & dados numéricos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos , Software
2.
Environ Pollut ; 226: 260-267, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28381348

RESUMO

Air pollution plays a pivotal role in the deterioration of many materials used in buildings and cultural monuments causing an inestimable damage. This study aims to estimate the impacts of air pollution (SO2, HNO3, O3, PM10) and meteorological conditions (temperature, precipitation, relative humidity) on limestone, copper and bronze based on high resolution air quality data-base produced with AMS-MINNI modelling system over the Italian territory over the time period 2003-2010. A comparison between high resolution data (AMS-MINNI grid, 4 × 4 km) and low resolution data (EMEP grid, 50 × 50 km) has been performed. Our results pointed out that the corrosion levels for limestone, copper and bronze are decreased in Italy from 2003 to 2010 in relation to decrease of pollutant concentrations. However, some problem related to air pollution persists especially in Northern and Southern Italy. In particular, PM10 and HNO3 are considered the main responsible for limestone corrosion. Moreover, the high resolution data (AMS-MINNI) allowed the identification of risk areas that are not visible with the low resolution data (EMEP modelling system) in all considered years and, especially, in the limestone case. Consequently, high resolution air quality simulations are suitable to provide concrete benefits in providing information for national effective policy against corrosion risk for cultural heritage, also in the context of climate changes that are affecting strongly Mediterranean basin.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Modelos Químicos , Poluição do Ar/análise , Carbonato de Cálcio , Clima , Cobre , Corrosão , Itália , Risco , Medição de Risco , Temperatura , Fatores de Tempo
3.
Environ Pollut ; 218: 586-594, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27522406

RESUMO

The interaction of pollutants with Cultural Heritage materials leads to artworks and materials degradation and loss, causing an unpriceless damage. This works aims to estimate the impacts of air pollution and meteorological conditions on limestone, copper and bronze and represents the European risk assessment for corrosion of Cultural Heritage materials. The measures and policies for atmospheric pollution reduction have cut off the SO2 concentration and consequently its impact on materials is drastically reduced. Indeed, in 1980 the number of UNESCO sites in danger was extremely high (94% for limestone, 54% for copper and 1% for bronze) while in 2010 these sites did not exceed the tolerable value of surface recession and corrosion. However, some problem related to air pollution persists. In particular, Random Forest Analysis (RFA), highlights PM10 as the main responsible for materials corrosion, in 2010. Two scenarios in 2030 have been tested, highlighting that the corrosion levels of limestone, copper and bronze exceed the tolerable limits only in the Balkan area and Turkey. Our results show the importance in the air quality modelling as a powerful tool for the UNESCO sites conservation.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Materiais de Construção , Monitoramento Ambiental , Carbonato de Cálcio/análise , Cobre/análise , Corrosão , Europa (Continente)
4.
Lab Anim ; 49(2): 89-99, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25416607

RESUMO

Directive 2010/63/EU was adopted in September 2010 by the European Parliament and Council, and became effective in January 2013. It replaces Directive 86/609/EEC and introduces new requirements for the protection of animals used for scientific purposes. In particular, it requires that establishments that breed, supply or use laboratory animals have a designated veterinarian (DV) with expertise in laboratory animal medicine, or a suitably qualified expert where more appropriate, charged with advisory duties in relation to the well-being and treatment of the animals. This paper is a report of an ESLAV/ECLAM/LAVA/EVERI working group that provides professional guidance on the role and postgraduate training of laboratory animal veterinarians (LAVs), who may be working as DVs under Directive 2010/63/EU. It is also aimed at advising employers, regulators and other persons working under the Directive on the role of the DV. The role and responsibilities of the DV include the development, implementation and continuing review of an adequate programme for veterinary care at establishments breeding and/or using animals for scientific purposes. The programme should be tailored to the needs of the establishment and based on the Directive's requirements, other legislations, and current guidelines in laboratory animal medicine. Postgraduate laboratory animal veterinary training should include a basic task-specific training module for DVs to complement veterinary competences from graduation, and continuing professional development on the basis of a gap analysis. A tiered approach to further training in laboratory animal veterinary medicine and science offers career development pathways that are mutually beneficial to LAVs and establishments.


Assuntos
Bem-Estar do Animal/normas , Animais de Laboratório , Educação em Veterinária/normas , Médicos Veterinários/normas , Animais , União Europeia
5.
Biol Neonate ; 71(5): 337-44, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9167855

RESUMO

Although lysophospholipids are normally found in the lung and their presence is connected to the metabolic pathway of surfactant phospholipids, several studies have reported that their intratracheal instillation is able to induce severe alveolar epithelial injury. Since lysophospholipids are normally present in exogenous surfactants as a consequence of the nonenzymatic hydrolysis of parent phospholipids during their production and shelf-life, the aim of this study was to test the potential toxicity of surfactant lysophospholipids in artificially ventilated newborn rabbits in comparison with that of pure lysophosphatidylcholine (Lyso-PC) suspensions. In premature (surfactant-deficient) animals, a commercially available Curosurf batch (0.56 mg Lyso-PC/ml) improved lung-thorax compliance and reduced lactate dehydrogenase (LDH), total protein and hemoglobin contents in bronchoalveolar lavage (BAL) fluid. The same batch submitted to thermal stress in order to increase the Lyso-PC content (10.2 mg Lyso-PC/ml) failed to improve lung mechanics but did not induce any significant change in biochemical markers in BAL fluid. When suspended in saline, pure Lyso-PC had a dramatic and dose-dependent tissue-damaging effect with increased LDH, hemoglobin and protein contents in BAL and a fall in the lungthorax compliance, in both immature and mature (near-term) animals. The lack of toxicity of Lyso-PC in Curosurf might be explained by an interaction with surfactant phospholipids.


Assuntos
Animais Recém-Nascidos/fisiologia , Lisofosfatidilcolinas/toxicidade , Alvéolos Pulmonares/efeitos dos fármacos , Mecânica Respiratória/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Líquido da Lavagem Broncoalveolar/química , Células Epiteliais , Epitélio/efeitos dos fármacos , Intubação Intratraqueal , Pulmão/química , Pulmão/fisiopatologia , Lisofosfatidilcolinas/administração & dosagem , Alvéolos Pulmonares/patologia , Coelhos , Taxa de Sobrevida
6.
Biol Neonate ; 65(6): 406-15, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8043702

RESUMO

Immature newborn rabbits delivered at a gestational age of 27 days were tracheotomized and treated, via the tracheal cannula, with clinically recommended doses of natural or synthetic surfactant (Curosurf and Exosurf, respectively). Littermates received 0.1% tyloxapol, 5% Tween 20, or saline. The dose volume of Curosurf was 2.5 ml/kg, that of the other materials 5 ml/kg. Animals were kept in a multiplethysmograph system and ventilated for 30 min with a standardized sequence of insufflation pressures. End-expiratory lung gas volume was calculated at the end of the experiment from measurements of lung weight and total lung volume. Tidal volumes were significantly improved in all groups of animals receiving surfactant or detergents. However, expiratory time constant (determined from the tidal volume tracing) was significantly longer, and end-expiratory gas volume significantly larger, in animals treated with Curosurf than in those receiving Exosurf or detergents. These differences were confirmed by semiquantitative evaluation of alveolar air expansion in histological sections. In addition, airway epithelial necrosis was reduced in animals receiving Curosurf, Exosurf, or Tween 20, but not in animals treated with tyloxapol. The discrepancy between improvements in tidal volume, expiratory time constant, and end-expiratory gas volume reflects failure of lung stabilization in animals treated with Exosurf or detergents, probably due to absence of specific hydrophobic proteins in the synthetic products.


Assuntos
Animais Recém-Nascidos , Produtos Biológicos , Detergentes/administração & dosagem , Álcoois Graxos/administração & dosagem , Pulmão/fisiopatologia , Fosfolipídeos , Fosforilcolina , Polietilenoglicóis/administração & dosagem , Surfactantes Pulmonares/administração & dosagem , Animais , Combinação de Medicamentos , Maturidade dos Órgãos Fetais , Pulmão/efeitos dos fármacos , Pulmão/embriologia , Coelhos , Testes de Função Respiratória
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...