70 research outputs found
Homogenous UV/Periodate Process for the Treatment of Acid Orange 10 Polluted Water
The photoactivated periodate (UV/IO4−) process is used to investigate the degradation of acid orange 10 (AO10) dye. The photodecomposition of periodate ions produces highly reactive radicals (i.e., •OH, IO3•, and IO4•) that accelerate dye degradation. Increasing the initial concentration of periodate to 3 mM enhances the dye removal rate, but over 3 mM periodate, the degradation rate slows down. On the contrary, increasing initial dye concentrations reduces the degradation performance. pH is the most critical factor in AO10 breakdown. Salts slow down the degradation of the dye. However, UV/IO4− is more efficient in distilled water than natural water. Even at low concentrations, surfactants may affect the dye’s decomposition rate. The addition of sucrose reduced the breakdown of AO10. Although tertbutanol is a very effective •OH radical scavenger, it does not affect the dye breakdown even at the highest concentrations. Accordingly, the AO10 degradation is a non-•OH pathway route. According to retrieved data, the photoactivated periodate method eliminated 56.5 and 60.5% of the initial COD after 60 and 120 min of treatment time; therefore, it can be concluded that the UV/IO4− system may treat effluents, especially those containing textile dyes
Influência da qualidade dos materiais de reprodução na reflorestação com sobreiro
O sobreiro ocupa em Portugal cerca de 721000 ha o que corresponde a 21,5 % da área fl orestal nacional e 33% da área
mundial (APCOR, 2005). A sua distribuição no território nacional traduz não só a sua adaptação a determinadas
condições edafo-climaticas, mas tem sido condicionada por várias circunstancias, como o arroteamento, o fogo, o
abuso do pastoreio, a exploração agrícola intensiva e as plantações fl orestais que contrariaram ou favoreceram a sua
existência nesses locais (Natividade, 1950). A distribuição desta espécie é particularmente signifi cativa em zonas
onde têm ocorrido acontecimentos climáticos graves e onde os níveis de desertifi cação humana são críticos.
A fi leira da cortiça salienta-se por Portugal ocupar o primeiro lugar entre os países produtores, transformadores e
exportadores de cortiça, correspondendo-lhe mais de metade da produção mundial desta matéria-prima. O nosso
País é a origem de aproximadamente 60% das transacções de cortiça a nível mundial, valor que sobe para 80%
quando nos referimos a transacções de produtos transformados. A nível nacional, o valor das exportações de cortiça
representam aproximadamente 0,7% do PIB, 2,24% das exportações e correspondem a mais de 33% do conjunto das
exportações de produtos fl orestais (APCOR, 2005). Para além da importância económica do sector corticeiro a nível
nacional, o aumento da consciência e do interesse da sociedade nas questões ambientais, faz com que o montado de
sobro seja reconhecido cada vez mais como um espaço fl orestal, de elevada biodiversidade, paisagísticamente único,
que potencia micro-economias locais baseadas numa agricultura e pastorícia extensivas, interessante para outras
actividades como o turismo rural e a caça.
O sobreiro tem sido a espécie fl orestal que mais tem benefi ciado dos meios fi nanceiros disponibilizados aos proprietários
fl orestais para a refl orestação no âmbito da aplicação das medidas de reforma da Política Agrícola Comum
da UE, na arborização das terras agrícolas. Contudo, têm-se registado com frequência elevadas taxas de insucesso
na arborização sendo a qualidade dos materiais florestais de reprodução (MFR) apontada como uma das causas.
Neste trabalho abordaremos a a qualidade dos materiais de reprodução, considerando-a do ponto de vista genético
e fisiológicoN/
Photocatalytic, sonocatalytic and sonophotocatalytic degradation of Rhodamine B using ZnO/CNTs composites photocatalysts
A series of ZnO nanoparticles decorated on multi-walled carbon nanotubes (ZnO/CNTs composites) was synthesized using a facile sol method. The intrinsic characteristics of as-prepared nanocomposites were studied using a variety of techniques including powder X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), transmission electron microscope (TEM), scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), Brunauer Emmett Teller (BET) surface area analyzer and X-ray photoelectron spectroscopy (XPS). Optical properties studied using UV–Vis diffuse reflectance spectroscopy confirmed that the absorbance of ZnO increased in the visible-light region with the incorporation of CNTs. In this study, degradation of Rhodamine B (RhB) as a dye pollutant was investigated in the presence of pristine ZnO nanoparticles and ZnO/CNTs composites using photocatalysis and sonocatalysis systems separately and simultaneously. The adsorption was found to be an essential factor in the degradation of the dye. The linear transform of the Langmuir isotherm curve was further used to determine the characteristic parameters for ZnO and ZCC-5 samples which were: maximum absorbable dye quantity and adsorption equilibrium constant. The natural sunlight and low power ultrasound were used as an irradiation source. The experimental kinetic data followed the pseudo-first order model in photocatalytic, sonocatalytic and sonophotocatalytic processes but the rate constant of sonophotocatalysis is higher than the sum of it at photocatalysis and sonocatalysis process. The sonophotocatalysis was always faster than the respective individual processes due to the more formation of reactive radicals as well as the increase of the active surface area of ZnO/CNTs photocatalyst. Chemical oxygen demand (COD)
of textile wastewater was measured at regular intervals to evaluate the mineralization of wastewater
Genetic polymorphisms of the RAS-cytokine pathway and chronic kidney disease
Chronic kidney disease (CKD) in children is irreversible. It is associated with renal failure progression and atherosclerotic cardiovascular (CV) abnormalities. Nearly 60% of children with CKD are affected since birth with congenital or inherited kidney disorders. Preliminary evidence primarily from adult CKD studies indicates common genetic risk factors for CKD and atherosclerotic CV disease. Although multiple physiologic pathways share common genes for CKD and CV disease, substantial evidence supports our attention to the renin angiotensin system (RAS) and the interlinked inflammatory cascade because they modulate the progressions of renal and CV disease. Gene polymorphisms in the RAS-cytokine pathway, through altered gene expression of inflammatory cytokines, are potential factors that modulate the rate of CKD progression and CV abnormalities in patients with CKD. For studying such hypotheses, the cooperative efforts among scientific groups and the availability of robust and affordable technologies to genotype thousands of single nucleotide polymorphisms (SNPs) across the genome make genome-wide association studies an attractive paradigm for studying polygenic diseases such as CKD. Although attractive, such studies should be interpreted carefully, with a fundamental understanding of their potential weaknesses. Nevertheless, whole-genome association studies for diabetic nephropathy and future studies pertaining to other types of CKD will offer further insight for the development of targeted interventions to treat CKD and associated atherosclerotic CV abnormalities in the pediatric CKD population
Characterization of the cork oak transcriptome dynamics during acorn development
Background: Cork oak (Quercus suber L.) has a natural distribution across western Mediterranean regions and is a keystone forest tree species in these ecosystems. The fruiting phase is especially critical for its regeneration but the molecular mechanisms underlying the biochemical and physiological changes during cork oak acorn development are poorly understood. In this study, the transcriptome of the cork oak acorn, including the seed, was characterized in five stages of development, from early development to acorn maturation, to identify the dominant processes in each stage and reveal transcripts with important functions in gene expression regulation and response to water.
Results: A total of 80,357 expressed sequence tags (ESTs) were de novo assembled from RNA-Seq libraries representative of the several acorn developmental stages. Approximately 7.6 % of the total number of transcripts present in Q. suber transcriptome was identified as acorn specific. The analysis of expression profiles during development returned 2,285 differentially expressed (DE) transcripts, which were clustered into six groups. The stage of development corresponding to the mature acorn exhibited an expression profile markedly different from other stages. Approximately 22 % of the DE transcripts putatively code for transcription factors (TF) or transcriptional regulators, and were found almost equally distributed among the several expression profile clusters, highlighting their major roles in controlling the whole developmental process. On the other hand, carbohydrate metabolism, the biological pathway most represented during acorn development, was especially prevalent in mid to late stages as evidenced by enrichment analysis. We further show that genes related to response to water, water deprivation and transport were mostly represented during the early (S2) and the last stage (S8) of acorn development, when tolerance to water desiccation is possibly critical for acorn viability.
Conclusions: To our knowledge this work represents the first report of acorn development transcriptomics in oaks. The obtained results provide novel insights into the developmental biology of cork oak acorns, highlighting transcripts putatively involved in the regulation of the gene expression program and in specific processes likely essential for adaptation. It is expected that this knowledge can be transferred to other oak species of great ecological value.Fundação para a Ciência e a Tecnologi
Nutrition in children with CRF and on dialysis
The objectives of this study are: (1) to understand the importance of nutrition in normal growth; (2) to review the methods of assessing nutritional status; (3) to review the dietary requirements of normal children throughout childhood, including protein, energy, vitamins and minerals; (4) to review recommendations for the nutritional requirements of children with chronic renal failure (CRF) and on dialysis; (5) to review reports of spontaneous nutritional intake in children with CRF and on dialysis; (6) to review the epidemiology of nutritional disturbances in renal disease, including height, weight and body composition; (7) to review the pathological mechanisms underlying poor appetite, abnormal metabolic rate and endocrine disturbances in renal disease; (8) to review the evidence for the benefit of dietetic input, dietary supplementation, nasogastric and gastrostomy feeds and intradialytic nutrition; (9) to review the effect of dialysis adequacy on nutrition; (10) to review the effect of nutrition on outcome
Prevalence of renal insufficiency in breast cancer patients and related pharmacological issues
Multi-complexity measures of heart rate variability and the effect of vasopressor titration: a prospective cohort study of patients with septic shock
A Nonlinear Elasticity Problem Governed by Lamé System
Abstract In this work we study a nonlinear problem equation governed by the system of Lamé, is similar example was the partial differential equations,which operates in relativistic quantum mechanics system.We look for the existence and uniqueness of a function u = u(x, t), x ∈ Ω , t ∈ (0, T ) solution of the problem. Notation Let Ω an open bounded domain of IR n , with regular boundary Γ.We denote by u = {u 1 , u 2 , u 3 , ...., u n } a vector and T a scalar function on Q τ = Ω×]0, τ [ where τ is a finite real number. λ, μ are the Lamé coefficients with λ ≥ 0 , μ > 0, γ > 0 is a constant. Let k > 0 be the coefficient of the termic conductivity.Our problem is to study a similar example was the partial differential equations, which operates in relativistic quantum mechanics. It means a Ω an open bounded domain of R n , with regular boundary Γ.We denot by Q the cylinder R n x × R t : Q = Ω × (0, T ), with boundary Σ. L designe Lamé system define by μΔ + (λ + μ)∇div; λ and μ are constants Lamé with λ+ μ ≥ 0. (u 0 , u 1 , f) functions, ρ > 0.We look for the existence and uniqueness of a function u = u(x, t), x ∈ Ω , t ∈ (0, T ) solution of the problem (1; 2; 3; 4)
Relationship between liquid depth and the acoustic generation of hydrogen: design aspect for large cavitational reactors with special focus on the role of the wave attenuation
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