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1.
BMC Microbiol ; 22(1): 126, 2022 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538413

RESUMO

Grapevine trunk diseases (GTDs) are a threat to grape production worldwide, with a diverse collection of fungal species implicated in disease onset. Due to the long-term and complex nature of GTDs, simultaneous detection of multiple microbial species can enhance understanding of disease development. We used DNA metabarcoding of ribosomal internal transcribed spacer 1 (ITS1) sequences, supported by specific PCR and microbial isolation, to establish the presence of trunk pathogens across 11 vineyards (11-26 years old) over three years in Marlborough, the largest wine producing region in New Zealand. Using a reference database of trunk pathogen sequences, species previously associated with GTD, such as Cadophora luteo-olivacea, Diplodia seriata, Diplodia mutila, Neofusicoccum australe, and Seimatosporium vitis, were identified as highly represented across the vineyard region. The well-known pathogens Phaeomoniella chlamydospora and Eutypa lata had especially high relative abundance across the dataset, with P. chlamydospora reads present between 22 and 84% (average 52%) across the vineyards. Screening of sequences against broader, publicly available databases revealed further fungal species within families and orders known to contain pathogens, many of which appeared to be endemic to New Zealand. The presence of several wood-rotting basidiomycetes (mostly Hymenochaetales) was detected for the first time in the Marlborough vineyard region, notably, the native Inonotus nothofagii which was present at 1-2% relative abundance in two vineyards.


Assuntos
Doenças das Plantas , Vitis , Adolescente , Adulto , Criança , Código de Barras de DNA Taxonômico , Fazendas , Humanos , Nova Zelândia , Doenças das Plantas/microbiologia , Vitis/microbiologia , Adulto Jovem
2.
BMC Pulm Med ; 19(1): 217, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31744499

RESUMO

BACKGROUND: Decades of clinical research into pulsed oxygen delivery has shown variable efficacy between users, and across a user's behaviours (sleep, rest, activity). Modern portable oxygen concentrators (POCs) have been shown as effective as other oxygen delivery devices in many circumstances. However, there are concerns that they are not effective during sleep when the breathing is shallow, and at very high respiratory rates as during physical exertion. It can be challenging to examine the determinants of POC efficacy clinically due to the heterogeneity of lung function within oxygen users, the diversity of user behaviour, and measurement issues. Representative bench testing may help identify key determinants of pulsed-oxygen device efficacy. METHODS: Three contemporary devices were bench-evaluated across three simulated breathing behaviours: activity, rest, & oronasal breathing during sleep. Emphasis was placed on breathing patterns representative of oxygen users. RESULTS: All three POCs performed well during simulated breathing during exertion and at rest. Differences in triggering ability were noted for the scenario of oronasal breathing during sleep. CONCLUSIONS: The results are supportive of contemporary POC triggering abilities. The differences shown in ultimate trigger sensitivity may have relevance to oronasal breathing during sleep or other challenging scenarios for pulsed oxygen delivery, such as dominant mouth breathing during exertion or unfavourable nasal geometry.


Assuntos
Oxigenoterapia/instrumentação , Oxigênio/administração & dosagem , Adulto , Cânula , Simulação por Computador , Humanos , Pulmão/fisiopatologia , Modelos Anatômicos , Oximetria , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/terapia , Ventilação Pulmonar , Fenômenos Fisiológicos Respiratórios , Sono
3.
Plant Dis ; 103(3): 519-525, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30632468

RESUMO

The grapevine trunk diseases Eutypa and Botryosphaeria dieback threaten the sustainability of vineyards worldwide. This study aimed to develop practical and efficient wound protection strategies, which will lead to widespread adoption of preventative control for these diseases and increased longevity of vineyards. Five fungicides (tebuconazole, carbendazim, fluazinam, mancozeb, and flusilazole) were evaluated for efficacy against Eutypa lata and Neofusicoccum luteum infection on pruning wounds of 'Sauvignon blanc' in a New Zealand vineyard. All five fungicides controlled infection by both pathogens to varying degrees, with mean percent disease control of 70 to 90% for E. lata and 33 to 93% for N. luteum. This has led to the first known registration of a fungicide, fluazinam (Gem), for simultaneous control of both Eutypa and Botryosphaeria dieback. Furthermore, application of carbendazim with tractor-driven sprayers provided similar control of E. lata and N. luteum to that when applied by hand with a paintbrush. This constitutes the first report of Botryosphaeria dieback control with fungicides applied with tractor-driven sprayers.


Assuntos
Ascomicetos , Fungicidas Industriais , Vitis , Ascomicetos/efeitos dos fármacos , Ascomicetos/fisiologia , Fungicidas Industriais/farmacologia , Nova Zelândia , Doenças das Plantas/prevenção & controle , Vitis/microbiologia
4.
BMC Pulm Med ; 17(1): 85, 2017 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-28535820

RESUMO

BACKGROUND: The lung-protective ventilation bundle has been shown to reduce mortality in adult acute respiratory distress syndrome (ARDS). This concept has expanded to other areas of acute adult ventilation and is recommended for pediatric ventilation. A component of lung-protective ventilation relies on a prediction of lean body weight from height. The predicted body weight (PBW) relationship employed in the ARDS Network trial is considered valid only for adults, with a dedicated formula required for each sex. No agreed PBW formula applies to smaller body sizes. This analysis investigated whether it might be practical to derive a unisex PBW formula spanning all body sizes, while retaining relevance to established adult protective ventilation practice. METHODS: Historic population-based growth charts were adopted as a reference for lean body weight, from pre-term infant through to adult median weight. The traditional ARDSNet PBW formulae acted as the reference for prevailing protective ventilation practice. Error limits for derived PBW models were relative to these references. RESULTS: The ARDSNet PBW formulae typically predict weights heavier than the population median, therefore no single relationship could satisfy both references. Four alternate piecewise-linear lean body-weight predictive formulae were presented for consideration, each with different balance between the objectives. CONCLUSIONS: The 'PBWuf + MBW' model is proposed as an appropriate compromise between prevailing practice and simplification, while also better representing lean adult body-weight. This model applies the ARDSNet 'female' formula to both adult sexes, while providing a tight fit to median body weight at smaller statures down to pre-term. The 'PBWmf + MBW' model retains consistency with current practice over the adult range, while adding prediction for small statures.


Assuntos
Peso Corporal , Modelos Biológicos , Respiração Artificial , Adolescente , Adulto , Estatura , Criança , Pré-Escolar , Feminino , Gráficos de Crescimento , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Conceitos Matemáticos , Valores de Referência , Adulto Jovem
5.
J Chem Phys ; 143(20): 204308, 2015 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-26627960

RESUMO

We present models for a heteronuclear diatomic molecular ion in a linear Paul trap in a rigid-rotor approximation, one purely classical and the other where the center-of-mass motion is treated classically, while rotational motion is quantized. We study the rotational dynamics and their influence on the motion of the center-of-mass, in the presence of the coupling between the permanent dipole moment of the ion and the trapping electric field. We show that the presence of the permanent dipole moment affects the trajectory of the ion and that it departs from the Mathieu equation solution found for atomic ions. For the case of quantum rotations, we also evidence the effect of the above-mentioned coupling on the rotational states of the ion.

6.
Phys Rev Lett ; 113(21): 217206, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25479521

RESUMO

We obtain a fundamental instability of the magnetization-switching fronts in superparamagnetic and ferromagnetic materials such as crystals of nanomagnets, ferromagnetic nanowires, and systems of quantum dots with large spin. We develop the instability theory for both linear and nonlinear stages. By using numerical simulations we investigate the instability properties focusing on spin avalanches in crystals of nanomagnets. The instability distorts spontaneously the fronts and leads to a complex multidimensional front dynamics. We show that the instability has a universal physical nature, with a deep relationship to a wide variety of physical systems, such as the Darrieus-Landau instability of deflagration fronts in combustion, inertial confinement fusion, and thermonuclear supernovae, and the instability of doping fronts in organic semiconductors.

7.
BMJ Mil Health ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38124226

RESUMO

INTRODUCTION: Canadian Armed Forces (CAF) members must complete an annual fitness evaluation. Members with a total hip arthroplasty (THA) may be at risk of injury during these strenuous tests. To inform CAF policy, we sought expert consensus on the safety of fitness testing for members with a THA. METHODS: We conducted a three-round Delphi study with a panel of hip arthroplasty experts to determine the safety of CAF operational fitness evaluations for members with a THA. The experts evaluated videos of the 10 individual tasks included in the evaluations. RESULTS: All individual tasks were judged to be safe by consensus. One task, which involves digging with a shovel, was considered safe provided that participants avoid deep hip flexion. The nine other tasks were judged to be safe without modifications or interventions. The experts also supported a policy recommendation that would allow members to perform military fitness evaluations if they (1) have a primary THA, (2) had no episodes of instability, (3) are at least 12 months postoperatively and (4) have been cleared by an orthopaedic surgeon and a physiatrist/physiotherapist. CONCLUSION: A panel of arthroplasty experts concluded, based on video analysis, that CAF fitness evaluations are generally safe for members with a THA.

8.
Clin Nutr ; 43(5): 1073-1078, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38579369

RESUMO

BACKGROUND & AIM: In hospitalized patients, daily protein intake remains far below WHO requirements for healthy adults (0.8 g·kg-1·d-1) as well as ESPEN guidelines for patients (1.2-1.5 g·kg-1·d-1). Providing access to a pre-sleep protein dense snack between dinner and going to bed may serve as a great opportunity to increase daily energy and protein intake in hospitalized patients. However, it remains to be assessed whether protein provision prior to sleep effectively increases protein intake, or may reduce food intake throughout the remainder of the day(s). The present study evaluated the impact of giving access to a pre-sleep snack on daily energy and protein intake in patients throughout their hospitalization. METHODS: Patients admitted to the surgical wards of the Maastricht University Medical Centre+ were randomly allocated to usual care (n = 51) or given access to a pre-sleep snack (n = 50). The pre-sleep snack consisted of 103 g cheese cubes (30 g protein) provided between 7:30 and 9:30 PM, prior to sleep. All food provided and all food consumed was weighed and recorded throughout (2-7 days) hospitalization. Daily energy and protein intake and distribution were calculated. Data were analyzed by independent T-Tests with P < 0.05 considered as statistically significant. RESULTS: Daily energy intake was higher in the pre-sleep group (1353 ± 424 kcal d-1) when compared to the usual care group (1190 ± 402 kcal·d-1; P = 0.049). Providing patients access to a pre-sleep snack resulted in a 17% (11 ± 9 g) higher daily protein intake (0.81 ± 0.29 g·kg-1·d-1) when compared to the usual care group (0.69 ± 0.28 g·kg-1·d-1; P = 0.045). Protein intake at breakfast, lunch, and dinner did not differ between the pre-sleep and usual care groups (all P > 0.05). CONCLUSION: Providing access to a pre-sleep protein snack, in the form of protein dense food items such as cheese, represents an effective dietary strategy to increase daily energy and protein intake in hospitalized patients. Patients consuming pre-sleep protein snacks do not compensate by lowering energy or protein intake throughout the remainder of the days. Pre-sleep protein dense food provision should be implemented in hospital food logistics to improve the nutritional intake of patients. TRIAL REGISTER NO: NL8507 (https://trialsearch.who.int/).


Assuntos
Proteínas Alimentares , Ingestão de Energia , Hospitalização , Sono , Lanches , Humanos , Masculino , Feminino , Proteínas Alimentares/administração & dosagem , Pessoa de Meia-Idade , Idoso , Sono/fisiologia , Adulto
9.
Rev Med Interne ; 44(11): 594-601, 2023 Nov.
Artigo em Francês | MEDLINE | ID: mdl-37438189

RESUMO

Since the discovery of DNA as the support of genetic information, the challenge for generations of life scientists was to understand the mechanisms underlying the process that translate the sequence of a gene to a phenotype. In the 1950s, the concept of epigenetics was defined by the British biologist Conrad H. Waddington as the study of "epigenesis" that governs the biological processes involved in the development of any organism. The term epigenetics, now best defined as "above the DNA sequence" reflects the gene-environment interactions by which genes determine traits. Since, its first description, studies underlying the mechanisms involved in these processes has led to an increasing understanding of the regulation all genome transactions such as transcription, replication, repair and the biological pathways coordinated by these mechanisms. We will discuss here the main principles regulating epigenetic processes, their roles in physiology, their evolution over the life time and their implications in medicine.


Assuntos
Metilação de DNA , Histonas , Humanos , Histonas/genética , Histonas/metabolismo , Epigênese Genética , Fenótipo , Interação Gene-Ambiente
10.
Front Microbiol ; 14: 1231832, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37680529

RESUMO

Grapevine trunk diseases (GTDs) are a substantial challenge to viticulture, especially with a lack of available control measures. The lack of approved fungicides necessitates the exploration of alternative controls. One promising approach is the investigation of disease escape plants, which remain healthy under high disease pressure, likely due to their microbiome function. This study explored the microbiome of grapevines with the disease escape phenotype. DNA metabarcoding of the ribosomal internal transcribed spacer 1 (ITS1) and 16S ribosomal RNA gene was applied to trunk tissues of GTD escape and adjacent diseased vines. Our findings showed that the GTD escape vines had a significantly different microbiome compared with diseased vines. The GTD escape vines consistently harbored a higher relative abundance of the bacterial taxa Pseudomonas and Hymenobacter. Among fungi, Aureobasidium and Rhodotorula were differentially associated with GTD escape vines, while the GTD pathogen, Eutypa, was associated with the diseased vines. This is the first report of the link between the GTD escape phenotype and the grapevine microbiome.

11.
Clin Nutr ; 42(8): 1436-1444, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37441814

RESUMO

BACKGROUND & AIMS: Hemodialysis removes amino acids from the circulation, thereby stimulating muscle proteolysis. Protein ingestion during hemodialysis can compensate for amino acid removal but may also increase uremic toxin production. Branched-chain ketoacid (BCKA) co-ingestion may provide an additional anabolic stimulus without adding to uremic toxin accumulation. In the present study we assessed the impact of BCKA co-ingestion with protein on forearm amino acid balance and amino acid oxidation during hemodialysis. METHODS: Nine patients (age: 73 ± 10 y) on chronic hemodialysis participated in this crossover trial. During two 4-h hemodialysis sessions, patients ingested 18 g protein with (PRO + BCKA) or without (PRO) 9 g BCKAs in a randomized order. Test beverages were labeled with L-[ring-13C6]-phenylalanine and provided throughout the last 3 h of hemodialysis as 18 equal sips consumed with 10-min intervals. Arterial and venous plasma as well as breath samples were collected frequently throughout hemodialysis. RESULTS: Arterial plasma total amino acid (TAA) concentrations during PRO and PRO + BCKA treatments were significantly lower after 1 h of hemodialysis (2.6 ± 0.3 and 2.6 ± 0.3 mmol/L, respectively) when compared to pre-hemodialysis concentrations (4.2 ± 1.0 and 4.0 ± 0.5 mmol/L, respectively; time effect: P < 0.001). Arterial plasma TAA concentrations increased throughout test beverage ingestion (time effect: P = 0.027) without differences between treatments (time∗treatment: P = 0.62). Forearm arteriovenous TAA balance during test beverage ingestion did not differ between timepoints (time effect: P = 0.31) or treatments (time∗treatment: P = 0.34). Whole-body phenylalanine oxidation was 33 ± 16% lower during PRO + BCKA when compared to PRO treatments (P < 0.001). CONCLUSIONS: BCKA co-ingestion with protein during hemodialysis does not improve forearm net protein balance but lowers amino acid oxidation.


Assuntos
Aminoácidos , Toxinas Urêmicas , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Cross-Over , Proteínas/metabolismo , Cetoácidos , Fenilalanina/metabolismo , Diálise Renal , Ingestão de Alimentos , Músculo Esquelético/metabolismo
12.
J Pharm Health Serv Res ; 13(3): 168-171, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36247367

RESUMO

Objective: One in four persons living with HIV in the USA is a woman. While the annual HIV diagnoses for 2019 decreased by approximately 9% when compared with 2015, this decrease was seen in men, while the rates remained stable for women. Pre-exposure prophylaxis (PrEP) is one major biomedical tool that could benefit women at risk of HIV. However, women only account for approximately 5% of PrEP users annually. The objective of this study is to identify and address the gender disparity in PrEP use. Methods: This study used epidemiological data from the AIDSVu database to confirm the presence of a gender disparity in PrEP use across the USA. Cross-sectional data from 2019 showed that PrEP use was significantly higher in men, which suggested the existence of a disparity. The PrEP-to-Need ratio was then used to examine the trends in PrEP use relative to the rate of HIV infections, from 2012 to 2019, and to confirm the existence of the gender disparity in PrEP use. Key findings: There is a marked gender disparity in PrEP use. This disparity is widening and therefore demands more attention to women at risk of HIV. Some recommendations for addressing the disparity include the following: raising awareness, capacity building for providers, scaling up efforts to better reach women at risk of HIV and additional research to understand the drivers of the disparity. Conclusions: Policy makers could therefore prioritize the health outcomes of women by promoting research and education aimed at extending PrEP offerings to effectively reach women.

13.
Opt Express ; 19(24): 23664-70, 2011 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-22109392

RESUMO

Natural lithography with 100-nm-diameter SiO(2) spheres followed by inductively coupled plasma etching was used to texture the surface of 4H-SiC for a wide-spectrum large-acceptance-angle anti-reflective layer. The surface showed low normal-incidence reflectance of < 5% over a wide spectrum from 250 nm to 550 nm. Photodiodes fabricated from the surface-textured SiC showed broader spectral and angular responsivity than SiC photodiodes with SiO(2) antireflective coating. The textured SiC photodiodes showed peak responsivity of 116 mA/W, large angle of acceptance angle (< 2% decrease in responsivity at 50° incident angle) and low dark current at 10V.


Assuntos
Compostos Inorgânicos de Carbono/química , Nanosferas/química , Nanotecnologia/instrumentação , Fotometria/instrumentação , Semicondutores , Compostos de Silício/química , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Fotografação/métodos , Espalhamento de Radiação
14.
J Environ Monit ; 13(1): 74-83, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20981383

RESUMO

The objective of the research work was to evaluate the efficiency of three different sampling methods (Ghost Wipe™, micro-vacuum, and ChemTest®) in the recovery of Be dust by assessing: (1) four Be compounds (beryllium acetate, beryllium chloride, beryllium oxide and beryllium aluminium), (2) three different surfaces (polystyrene, glass and aluminium) and (3) inter-operator variation. The three sampling methods were also tested on site in a laboratory of a dental school for validation purposes. The Ghost Wipe™ method showed recovery ranging from 43.3% to 85.8% for all four Be compounds and for all three quantities of Be spiked on Petri dishes, while recovery with the micro-vacuum method ranged from 0.1% to 12.4%. On polystyrene dishes with 0.4 µg Be, the recovery ranged from 48.3% to 81.7%, with an average recovery of 59.4% for Operator 1 and 68.4% for Operator 2. The ChemTest® wipe method with beryllium acetate, beryllium chloride, and AlBeMet® showed analogous results that are in line with the manufacturer's manual, but collection of beryllium oxide was negative. In the dental laboratory, Ghost Wipe™ samplings showed better recovery than the micro-vacuum method. The ratios between the recovered quantities of Be in each location where the Ghost Wipe™ was tested differed substantially, ranging from 1.45 to 64. In the dental laboratory, a faint blue color indicating the presence of Be was observed on the ChemTest® wipes used in two locations out of six. In summary, the Ghost Wipe™ method was more efficient than micro-vacuuming in collecting the Be dust from smooth, non-porous surfaces such as Petri dishes by a factor of approximately 18. The results obtained on site in a dental laboratory also showed better recovery with Ghost Wipes™. However, the ratio of Be recovered by Ghost Wipes™ versus micro-vacuuming was much lower for surfaces where a large amount of dust was present. Wet wiping is preferred over micro-vacuuming for beryllium forms, but this conclusion probably applies to the ultra-low particulate loading levels (0.4 micrograms or less) which was tested in this study.


Assuntos
Berílio/análise , Técnicas de Química Analítica/métodos , Poeira/análise , Poluentes Ambientais/análise , Manejo de Espécimes/métodos , Propriedades de Superfície , Vácuo
15.
Exp Eye Res ; 91(1): 63-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20398654

RESUMO

We demonstrate an optical instrument that can measure the axial displacement of different eye tissues, including the cornea and the fundus. The instrument is based on spectral-domain low-coherence interferometry, which extracts displacement information from sequential axial scans of the eye with 100 Hz sampling frequency and with a precision of 400 nm. Longitudinal retinal and corneal movements were successfully measured in vivo in live rats, and Fourier analysis of the signal revealed the signature of the respiratory and cardiac cycles at 1.0 and 3.5 Hz, respectively. The effective amplitudes of retinal and corneal displacements at the cardiac frequency were found to be about 1.10 and 1.37 mum, respectively. The synchrony and direction of these two movements relative to the systole and diastole were found to be nearly the same. This novel instrument can be applied to assess biomechanical properties of the eye, which could be important for early diagnosis and for understanding the pathophysiology of glaucoma and other ocular diseases.


Assuntos
Córnea/fisiologia , Técnicas de Diagnóstico Oftalmológico/instrumentação , Movimentos Oculares/fisiologia , Retina/fisiologia , Animais , Fenômenos Biomecânicos , Corioide/irrigação sanguínea , Análise de Fourier , Frequência Cardíaca/fisiologia , Interferometria/instrumentação , Luz , Oximetria , Fluxo Pulsátil , Ratos , Reprodutibilidade dos Testes
16.
J Mech Behav Biomed Mater ; 110: 103944, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32957237

RESUMO

BACKGROUND: During revision total knee arthroplasty (rTKA), proximal tibial bone loss is frequently encountered and can result in a less-stable bone-implant fixation. A 3D printed titanium revision augment that conforms to the irregular shape of the proximal tibia was recently developed. The purpose of this study was to evaluate the fixation stability of rTKA with this augment in comparison to conventional cemented rTKA. METHODS: Primary total knee arthroplasty (pTKA) surgery was performed on 11 pairs of thawed fresh-frozen cadaveric tibias (22 tibias). Fixation stability testing was conducted using a three-stage eccentric loading protocol. Bone-implant micromotion was measured using a high-resolution optical system. The pTKA were removed. Revision TKA was performed using a 3D printed titanium augment or a standard fully cemented stem. The three-stage eccentric loading protocol was repeated and micromotion was measured for the revision implants. RESULTS: After rTKA, the mean vertical micromotion was 28.1 µm ± (SD) 20.3 µm in the control group and 17.5 µm ± 18.7 µm in the experimental group. There was significantly less micromotion in the experimental group (p = 0.029). CONCLUSIONS: This study suggests that early fixation stability of revision TKA with the novel 3D printed titanium augment is better then the conventional fully cemented rTKA. The early press-fit fixation of the augment is likely sufficient for promoting bony ingrowth of the augment in vivo. Further studies are needed to investigate the long-term in-vivo fixation of the novel 3D printed augment.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Cadáver , Humanos , Impressão Tridimensional , Desenho de Prótese , Tíbia/cirurgia , Titânio
17.
Ann Occup Hyg ; 53(7): 669-75, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19605417

RESUMO

The objective of the present work was to estimate the efficiency of moistened wipes in removing beryllium with different solutions including Citranox, Alconox, NaCl 5%, Resolve, and Ledizolv on various types of surfaces such as unpainted metal, wood frames, painted metal, concrete, painted concrete, and Plexiglas from three different occupational settings. Of the three plants that were investigated, only surfaces in the aluminium smelter were decontaminated down to the clearance reference level of 0.2 microg 100 cm(-2), with all the solvents used. In the machine tooling and milling department, the clearance level of 0.2 microg 100 cm(-2) was reached after the three decontaminations, with all the solvents. In the machine plant for the military, aerospace, and telecommunications industries, the beryllium concentrations on the concrete wall, before decontamination with the high-pressure gun, were usually >3 microg 100 cm(-2), and concentrations as high as 31 microg 100 cm(-2) were measured. After the high-pressure cleanup, the beryllium concentrations were sometimes reduced by a factor of 10, but never reached the clearance level. Beryllium compounds that had adhered to most types of structures that we attempted to decontaminate were reduced to below the clearance reference value except on concrete floors. There did not seem to be any difference between the decontamination actions for all the solvents used in this study.


Assuntos
Poluentes Ocupacionais do Ar , Berílio , Descontaminação/métodos , Exposição por Inalação/prevenção & controle , Exposição Ocupacional/prevenção & controle , Solventes/química , Monitoramento Ambiental/métodos , Luvas Protetoras , Humanos , Indústrias/normas , Teste de Materiais/métodos , Permeabilidade , Medição de Risco , Solventes/análise
18.
Ann Occup Hyg ; 53(4): 353-62, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19254960

RESUMO

Exposure to beryllium compounds, both by inhalation and skin contact, may result in immune sensitization and chronic beryllium disease. The objective of the present research work was to study the feasibility of removing beryllium compounds from the surfaces of devices made of Be-Cu alloy and to estimate the frequency at which the surfaces had to be rubbed in order to evaluate the likelihood that beryllium can be removed from the surfaces by serial wipe sampling at concentrations exceeding the US Department of Energy (DOE) standard limit of 0.2 microg per 100 cm2. The standard limit was exceeded after successive cleanings of moulds and plates made of Be-Cu alloy with solvents such Citranox, an acidic solvent, Alconox, Z-99 and Fantastik, basic solvents, or more neutral solvents such as Luminox and water. Citranox was the best solvent for extracting beryllium from the tested surfaces, while Alconox seemed to be the second best one. In general, warm water, Luminox and Z-99 seemed to be less efficient for extracting Be from all equipment. The results of the present study suggest that Ghost Wipes, when passed across a surface under the firm pressure of an individual's hand, can be used to detect beryllium contamination. However, they seem to show low reliability for quantification. From a safety standpoint in occupational settings, workers should be offered skin protection and respiratory protection if they have to handle devices made of Be-Cu alloy.


Assuntos
Poluentes Ocupacionais do Ar/análise , Ligas/química , Berílio/análise , Descontaminação/métodos , Monitoramento Ambiental/métodos , Solventes/farmacologia , Cobre , Estudos de Viabilidade , Humanos , Exposição por Inalação , Saúde Ocupacional , Medição de Risco/métodos , Absorção Cutânea
19.
J Occup Environ Hyg ; 6(11): 687-97, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19757293

RESUMO

To examine the influence of the sampling method on beryllium (Be) exposure assessment, a study was conducted in foundries and smelters to contrast the performance of five different dust sampling devices. Six sampling surveys were conducted in four different settings, and both personal and fixed station samples were collected using the following sampling heads: IOM samplers (inhalable dust), 35-mm plastic cassettes (total dust), aluminum SKC cyclones (respirable dust), 8-stage Sierra cascade impactors, and 12-stage MOUDI impactors. In total, beryllium concentrations were determined for 66/68 inhalable dust samples, 62/62 total dust samples, 56/57 respirable dust samples, 54/64 8-stage Sierra samples, and 19/25 12-stage MOUDI samples. In the magnesium foundry and aluminum smelters, the concentrations obtained during specific tasks could exceed the actual permissible exposure limit of the province of Quebec (0.15 microg/m(3)) or of the ACGIH threshold limit value (TLV) (0.05 microg/m(3)). The median of median dust concentration ratios computed from the sampling heads at the fixed station decreased as follows: IOM (1.00) > Sierra (0.76) > 37-mm cassette (0.61) > MOUDI (0.48) > respirable (0.12). The same trends were observed with the ratios of the median of median Be concentrations at the fixed station but with a larger scattering within sampling heads as follows: IOM (1.00) > Sierra (0.69) > 37-mm cassette (0.64) > MOUDI (0.54) > respirable (0.19). The median of median ratios of dust (IOM (1.00) > Sierra (0.56) > 37-mm cassette (0.35) > respirable (0.06)) and Be (IOM (1.00) > Sierra (0.66) > 37-mm cassette (0.48) > respirable (0.11)) in dust were lower, and there was less scattering for the 37-mm cassette and SKC cyclone used during breathing zone sampling than for the same sampling heads at the fixed station. Inhalable aerosol measurements should remain the tool for estimating the risk of exposure to beryllium in these settings until a clear dose response is established for these sampling heads.


Assuntos
Poluentes Ocupacionais do Ar/análise , Berílio/análise , Monitoramento Ambiental/métodos , Resíduos Industriais/análise , Metalurgia , Aerossóis/análise , Alumínio , Poeira/análise , Humanos , Exposição por Inalação/análise , Magnésio , Exposição Ocupacional/análise , Quebeque
20.
Bull Environ Contam Toxicol ; 82(4): 440-3, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19183819

RESUMO

Exposure assessment was performed during the abatement of amosite containing material (ACM) and chrysotile containing material (CCM). Mean fibre concentrations (MFC) in breathing zone (BZ) were 20.6+/-7.9 f/cc and 6.3+/-2.2 f/cc during abatements of ACM and CCM, respectively. At the fixed station, MFC were 5.4+/-3.5 f/cc for ACM and 2.9 f/cc+/-1.6 for CCM. For observer's BZ, MFC were 3.1+/-1.3 f/cc (ACM) and 1.8 f/cc (CCM) during the abatement. Though elevated, area and observer-type samples clearly underestimate exposure. Exposure remained unacceptable in the worksite with the class of respiratory protection used.


Assuntos
Poluentes Ocupacionais do Ar/análise , Amianto/análise , Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental/análise , Fibras Minerais/análise , Asbestose , Materiais de Construção , Exposição Ambiental , Habitação , Humanos , Exposição por Inalação
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