1,287 research outputs found
uncertainty analysis of cell counting by metabolic assays
Cell counting is a fundamental procedure in living cell culture-based experiments and protocols in which the cell number quantification is required. The number of cells is one of the parameters necessary to investigate several cell culture features requiring to be monitored as function of time, such as cell viability, proliferation, growth, fitness and metabolism. Aim of this paper is contributing to declare a comprehensive uncertainty budget for cell counting through metabolic assays according to the EURACHEM/CITAC Guide Quantifying Uncertainty in Analytical Measurement
How did italian adolescents with disability and parents deal with the covid-19 emergency?
The COVID-19 emergency has imposed distanced education and has interrupted most rehabilitation services. Adolescents with disabilities have been isolated, and the burden on their families has been exacerbated. A cross-sectional survey was administered to adolescents with disability and to parents of disabled children to describe their experience during lockdown and their concerns or expectations about rehabilitation. A sample of 53 adolescents and 239 parents completed the survey. Adolescents were ages 13\u201318 years old (45.3% female). Most parents were between 35 and 55 years old (84.9% female). While 53.6% of the parents reported no positive effects of the lockdown, 92.5% of the adolescents expressed favorable consequences. The increased time spent with family members was judged positively by 27.2% of parents and by 64.2% of adolescents. Concern for their child\u2019s disability was expressed by 47.3% of parents, while 73.6% of adolescents expressed concerns regarding the ban on meeting friends. In both groups, anxiety symptoms were correlated with the fear of contracting COVID-19 and with financial problems. Parents would have liked even more remote support from school and healthcare professionals, which was available for most participants. Thus, socioeconomic support, assistive technology and telerehabilitation strategies might help families with disabilities during a lockdown
Desempenho de habitações de interesse social frente às mudanças climáticas = Performance of social housing in relation to climate change
O objetivo deste artigo é realizar uma investigação inicial considerando impactos no desempenho termo energético em longo prazo frente à s mudanças climáticas de projetos que estão sendo desenvolvidos para o setor de habitação social no paÃs. Um projeto representativo estimado com base no levantamento de projetos nacionais foi usado como estudo de caso nas cidades de São Paulo e Salvador. A avaliação usou simulação termo energética considerando arquivos climáticos atuais e de previsão futura. Foi realizada uma caracterização de usos finais e padrão de uso de habitações de interesse social com base em pesquisas nacionais. Os resultados avaliados foram comparados usando-se indicadores de consumo de energia, emissões de carbono e conforto térmico do usuário e mostraram aumento acentuado com relação aos indicadores de resfriamento, refrigeração e desconforto por calor para os climas futuros. = This article seeks to carry out an initial investigation considering impacts on thermal and energy long-term performance of projects developed for national programs of social housing in view of climate change. A representative project estimated based on a survey of national projects was used as case study in São Paulo and Salvador. The evaluation used thermal and energy simulation considering current and future climate scenarios. It was conducted a characterization of end uses and usage pattern of social housing based on national surveys. Results were compared using as indicators, energy consumption, carbon emissions and user thermal comfort and showed an increase with respect to cooling indicators and discomfort for heat in future climates
Modelling the impacts of ammonia emissions reductions on North American air quality
A unified regional air-quality modelling system (AURAMS) was used to investigate the effects of reductions in ammonia emissions on regional air quality, with a focus on particulate-matter formation. Three simulations of one-year duration were performed for a North American domain: (1) a base-case simulation using 2002 Canadian and US national emissions inventories augmented by a more detailed Canadian emissions inventory for agricultural ammonia; (2) a 30% North-American-wide reduction in agricultural ammonia emissions; and (3) a 50% reduction in Canadian beef-cattle ammonia emissions. The simulations show that a 30% continent-wide reduction in agricultural ammonia emissions lead to reductions in median hourly PM<sub>2.5</sub> mass of <1 μg m<sup>&minus;3</sup> on an annual basis. The atmospheric response to these emission reductions displays marked seasonal variations, and on even shorter time scales, the impacts of the emissions reductions are highly episodic: 95th-percentile hourly PM<sub>2.5</sub> mass decreases can be up to a factor of six larger than the median values. <br><br> A key finding of the modelling work is the linkage between gas and aqueous chemistry and transport; reductions in ammonia emissions affect gaseous ammonia concentrations close to the emissions site, but substantial impacts on particulate matter and atmospheric deposition often occur at considerable distances downwind, with particle nitrate being the main vector of ammonia/um transport. Ammonia emissions reductions therefore have trans-boundary consequences downwind. Calculations of critical-load exceedances for sensitive ecosystems in Canada suggest that ammonia emission reductions will have a minimal impact on current ecosystem acidification within Canada, but may have a substantial impact on future ecosystem acidification. The 50% Canadian beef-cattle ammonia emissions reduction scenario was used to examine model sensitivity to uncertainties in the new Canadian agricultural ammonia emissions inventory, and the simulation results suggest that further work is needed to improve the emissions inventory for this particular sector. It should be noted that the model in its current form neglects coarse mode base cation chemistry, so the predicted effects of ammonia emissions reductions shown here should be considered upper limits
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Persistence of upper stratospheric wintertime tracer variability into the Arctic spring and summer
Using data from the Aeronomy of Ice in the Mesosphere (AIM) and Aura
satellites, we have categorized the interannual variability of winter- and
springtime upper stratospheric methane (CH4). We further show the effects
of this variability on the chemistry of the upper stratosphere throughout the
following summer. Years with strong wintertime mesospheric descent followed
by dynamically quiet springs, such as 2009, lead to the lowest summertime
CH4. Years with relatively weak wintertime descent, but strong springtime
planetary wave activity, such as 2011, have the highest summertime CH4. By
sampling the Aura Microwave Limb Sounder (MLS) according to the occultation
pattern of the AIM Solar Occultation for Ice Experiment (SOFIE), we show that
summertime upper stratospheric chlorine monoxide (ClO) almost perfectly
anticorrelates with the CH4. This is consistent with the reaction of
atomic chlorine with CH4 to form the reservoir species, hydrochloric acid
(HCl). The summertime ClO for years with strong, uninterrupted mesospheric
descent is about 50 % greater than in years with strong horizontal
transport and mixing of high CH4 air from lower latitudes. Small, but
persistent effects on ozone are also seen such that between 1 and 2 hPa, ozone
is about 4–5 % higher in summer for the years with the highest CH4
relative to the lowest. This is consistent with the role of the chlorine
catalytic cycle on ozone. These dependencies may offer a means to monitor
dynamical effects on the high-latitude upper stratosphere using summertime
ClO measurements as a proxy. Additionally, these chlorine-controlled ozone decreases,
which are seen to maximize after years with strong uninterrupted wintertime
descent, represent a new mechanism by which mesospheric descent can affect
polar ozone. Finally, given that the effects on ozone appear to persist much
of the rest of the year, the consideration of winter/spring dynamical
variability may also be relevant in studies of ozone trends
Biological and technical variables affecting immunoassay recovery of cytokines from human serum and simulated vaginal fluid: A multicenter study
The increase of proinflammatory cytokines in vaginal secretions may serve as a surrogate marker of unwanted inflammatory reaction to microbicide products topically applied for the prevention of sexually transmitted diseases, including HIV-1. Interleukin (IL)-1β and IL-6 have been proposed as indicators of inflammation and increased risk of HIV-1 transmission; however, the lack of information regarding detection platforms optimal for vaginal fluids and interlaboratory variation limit their use for microbicide evaluation and other clinical applications. This study examines fluid matrix variants relevant to vaginal sampling techniques and proposes a model for interlaboratory comparisons across current cytokine detection technologies. IL-1β and IL-6 standards were measured by 12 laboratories in four countries, using 14 immunoassays and four detection platforms based on absorbance, chemiluminescence, electrochemiluminescence, and fluorescence. International reference preparations of cytokines with defined biological activity were spiked into (1) a defined medium simulating the composition of human vaginal fluid at pH 4.5 and 7.2, (2) physiologic salt solutions (phosphate-buffered saline and saline) commonly used for vaginal lavage sampling in clinical studies of cytokines, and (3) human blood serum. Assays were assessed for reproducibility, linearity, accuracy, and significantly detectable fold difference in cytokine level. Factors with significant impact on cytokine recovery were determined by Kruskal−Wallis analysis of variance with Dunn’s multiple comparison test and multiple regression models. All assays showed acceptable intra-assay reproducibility; however, most were associated with significant interlaboratory variation. The smallest reliably detectable cytokine differences (P < 0.05) derived from pooled interlaboratory data varied from 1.5- to 26-fold depending on assay, cytokine, and matrix type. IL-6 but not IL-1β determinations were lower in both saline and phosphate-buffered saline as compared to vaginal fluid matrix, with no significant effect of pH. The (electro)chemiluminescence-based assays were most discriminative and consistently detected <2-fold differences within each matrix type. The Luminex-based assays were less discriminative with lower reproducibility between laboratories. These results suggest the need for uniform vaginal sampling techniques and a better understanding of immunoassay platform differences and cross-validation before the biological significance of cytokine variations can be validated in clinical trials. This investigation provides the first standardized analytic approach for assessing differences in mucosal cytokine levels and may improve strategies for monitoring immune responses at the vaginal mucosal interface
Preformulation and stability in biological fluids of the retrocyclin RC-101, a potential anti-HIV topical microbicide
<p>Abstract</p> <p>Background</p> <p>RC-101, a cationic peptide retrocyclin analog, has <it>in vitro </it>activity against HIV-1. Peptide drugs are commonly prone to conformational changes, oxidation and hydrolysis when exposed to excipients in a formulation or biological fluids in the body, this can affect product efficacy. We aimed to investigate RC-101 stability under several conditions including the presence of human vaginal fluids (HVF), enabling the efficient design of a safe and effective microbicide product. Stability studies (temperature, pH, and oxidation) were performed by HPLC, Circular Dichroism, and Mass Spectrometry (LC-MS/MS). Additionally, the effect of HVF on formulated RC-101 was evaluated with fluids collected from healthy volunteers, or from subjects with bacterial vaginosis (BV). RC-101 was monitored by LC-MS/MS for up to 72 h.</p> <p>Results</p> <p>RC-101 was stable at pH 3, 4, and 7, at 25 and 37°C. High concentrations of hydrogen peroxide resulted in less than 10% RC-101 reduction over 24 h. RC-101 was detected 48 h after incubation with normal HVF; however, not following incubation with HVF from BV subjects.</p> <p>Conclusions</p> <p>Our results emphasize the importance of preformulation evaluations and highlight the impact of HVF on microbicide product stability and efficacy. RC-101 was stable in normal HVF for at least 48 h, indicating that it is a promising candidate for microbicide product development. However, RC-101 stability appears compromised in individuals with BV, requiring more advanced formulation strategies for stabilization in this environment.</p
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