RESUMO
As part of an ongoing study of the structure and properties of mixtures of ionic liquids in which one component has a hydrocarbon chain and the other a semiperfluorocarbon chain, we now report a study of the mixtures [C8MIM]1-x[C10MIM-F17]x[Tf2N], [C10MIM]1-x[C8MIM-F13]x[Tf2N] and [C10MIM]1-x[C10MIM-F17]x[Tf2N], where [C8MIM][Tf2N] is 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide, [C10MIM][Tf2N] is 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C8MIM-F13][Tf2N] is 1-(1H,1H,2H,2H-perfluorooctyl)-3-methylimidizolium bis(trifluoromethylsulfonyl)imide and [C10MIM-F17][Tf2N] is 1-(1H,1H,2H,2H-perfluorodecyl)-3-methylimidizolium bis(trifluoromethylsulfonyl)imide. The mixtures were investigated using small-angle X-ray (SAXS) and neutron (SANS) scattering complemented by molecular dynamics simulations (with viscosity and surface tension measurements also possible for the mixtures [C10MIM]1-x[C8MIM-F13]x[Tf2N]). Unlike previous studies of [C8MIM]1-x[C8MIM-F13]x[Tf2N], where no strong evidence of alkyl/fluoroalkyl chain segregation or triphilic behaviour was seen (Elstone et al., J. Phys. Chem. B, 2023, 127, 7394-7407), these new mixtures show the formation of small aggregates of varying sizes of each component, even though all were co-miscible across the full range of compositions. Thus, while a clear polar non-polar peak (PNPP) was observed at large or small values of x, at intermediate compositions the small-angle neutron scattering at low q was dominated by scattering from these small aggregates, while at other compositions, there was little or no evidence of the PNPP. The origins of this behaviour are discussed in terms of inter-chain interactions.
RESUMO
Introduction: Rituximab (RTX) has been reported as an effective treatment alternative in primary forms of minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) associated with steroid dependence and frequent relapses. However, the optimal RTX regimen and the outcomes of further doses of RTX remain unclear. This study aimed to evaluate the use of induction and maintenance RTX therapy for adults with primary podocytopathies. Methods: We performed a retrospective case series on adult patients with steroid-dependent podocytopathies who received an induction RTX therapy. Maintenance therapy was performed at physician's discretion. Remission and relapse rates, concomitant corticosteroids and immunosuppressants use, B-cell depletion and adverse events were analyzed. Results: Fourteen patients (mean age at start of RTX 29.1 ± 21.9 years) with MCD (n = 7) or FSGS (n = 7) were treated with 2 doses of 1,000 mg 2 weeks apart (n = 13) or four doses of 375 mg/m2 (n = 1) of RTX. At last follow-up (mean 47.3 ± 101.7 months), 10 patients were in complete remission and two remained in partial remission. A reduction in the number of relapses, number of patients under corticosteroids and immunosuppressants, and dose of prednisolone was observed when compared to baseline (14 [100%] vs. 5 [35.7%]; 8/14 [57.1%] vs. 4/12 [33.3%]; 13/14 [92.9%] vs. 7/12 [58.3%]; 20 mg/day vs. 5.25 mg/day, respectively). Maintenance RTX therapy was used in 6 patients, with sustained complete remission. Infusion reactions were observed in 4 patients (one required treatment withdrawal). Conclusions: Our findings support the use of RTX for a steroid-free remission in podocytopathies and suggest that maintenance RTX is well-tolerated and associated with prolonged remission. Further studies are needed to confirm its efficacy and safety and establish the optimal induction and maintenance RTX regimen in steroid-dependent podocytopathies.
Rituximab (RTX) seems to be an effective treatment alternative in primary forms of MCD and FSGS, particularly in cases of steroid dependence and frequent relapses. Our findings support the use of RTX for a steroid-free remission in podocytopathies and suggest that maintenance RTX is well-tolerated and associated with prolonged remission. Further studies are needed to confirm its efficacy and safety and establish the optimal induction and maintenance RTX regimen in steroid-dependent podocytopathies.
RESUMO
This study introduces an innovative approach to the layered model, emphasizing the physical-chemical characterization of miscible liquid systems through ultrasonic techniques, with a specific focus on the water-ethanol system used in pharmaceutical formulations. Traditional characterization methods, while effective, face challenges due to the complex nature of solutions, such as the need for large pressure variations and strict temperature control. The proposed approach integrates partial molar volumes and partial propagation velocity functions into the layered model, enabling a nuanced understanding of miscibility and interactions. Ultrasonic techniques are used to calculate the isentropic compressibility coefficient for each component of the mixture as well as the total value using an additive mixing rule. Unlike conventional methods, this technique uses tabulated and experimental data to estimate the propagation velocity in the mixture, leading to a more precise computation of the isentropic compressibility coefficient. The results indicate a significant improvement in predicting the behavior of the water-ethanol system compared to the classical layered model. The methodology demonstrates the potential to provide new physicochemical insights that can be applied to other miscible systems beyond water-ethanol. This research has implications for improving the efficiency and accuracy of liquid medication formulations in the pharmaceutical industry.
RESUMO
Septins are cytoskeletal proteins and their interaction with membranes is crucial for their role in various cellular processes. Septins have polybasic regions (PB1 and PB2) which are important for lipid interaction. Earlier, we and others have highlighted the role of the septin C-terminal domain (CTD) to membrane interaction. However, detailed information on residues/group of residues important for such feature is lacking. In this study, we investigate the lipid-binding profile of Schistosoma mansoni Septin10 (SmSEPT10) using PIP strip and Langmuir monolayer adsorption assays. Our findings highlight the CTD as the primary domain responsible for lipid interaction in SmSEPT10, showing binding to phosphatidylinositol phosphates. SmSEPT10 CTD contains a conserved polybasic region (PB3) present in both animals and fungi septins, and a Lys (K367) within its putative amphipathic helix (AH) that we demonstrate as important for lipid binding. PB3 deletion or mutation of this Lys (K367A) strongly impairs lipid interaction. Remarkably, we observe that the AH within a construct lacking the final 43 amino acid residues is insufficient for lipid binding. Furthermore, we investigate the homocomplex formed by SmSEPT10 CTD in solution by cross-linking experiments, CD spectroscopy, SEC-MALS and SEC-SAXS. Taken together, our studies define the lipid-binding region in SmSEPT10 and offer insights into the molecular basis of septin-membrane binding. This information is particularly relevant for less-studied non-human septins, such as SmSEPT10.
RESUMO
This article assesses the environmental impacts of aquatic biota cultivation, focusing on shrimp farming in Brazil's Northeast, as this practice has proven to be one of the main sources of economic growth in the region. For this purpose, sediment samples were collected from areas impacted and not directly impacted by shrimp farming, and concentrations of key geochemical parameters such as salinity, various elements (K, P, Cu, Mn, Pb, Zn, Al, Ca, Fe, Mg, and Na), and natural radionuclides (K-40, Ra-226 and Ra-228) were compared using statistical tools. Element concentrations were determined using ICP-OES, and naturally occurring radionuclide concentrations were obtained through gamma spectrometry. Statistical tests, such as ANOVA and/or Mann-Whitney, cluster analysis, and principal component analysis, were applied to the results. Additionally, the ERICA Tool software was employed to estimate deleterious effects on both human and non-human biota. Descriptive statistics reveal variability in sediment parameters around shrimp farming. ANOVA and Mann-Whitney tests compare concentrations of shrimp farm sediment and not directly impacted sediment, showing non-significant differences for most elements. pH and salinity, crucial for shrimp health, exhibit higher values in shrimp farm sediment. Alkali and alkaline earth metals, including K and Na, show no significant differences. Factor and cluster analyses suggest that certain elements, mainly radionuclides, are influenced by sediment variability. Hazard indices for naturally occurring radionuclides indicate negligible risk to both human and non-human biota, reinforcing the absence of adverse effects from shrimp farming activities. This study provides a comprehensive analysis of the environmental impacts of shrimp farming, emphasizing the importance of monitoring geochemical parameters for coastal environmental management.
Assuntos
Aquicultura , Sedimentos Geológicos , Sedimentos Geológicos/química , Sedimentos Geológicos/análise , Animais , Brasil , Metais/análise , Poluentes Químicos da Água/análise , Radioisótopos/análise , Salinidade , Monitoramento Ambiental/métodos , Penaeidae/química , Concentração de Íons de HidrogênioRESUMO
Sepsis-associated kidney injury is common in critically ill patients and significantly increases morbidity and mortality rates. Several complex pathophysiological factors contribute to its presentation and perpetuation, including macrocirculatory and microcirculatory changes, mitochondrial dysfunction, and metabolic reprogramming. Recovery from acute kidney injury (AKI) relies on the evolution towards adaptive mechanisms such as endothelial repair and tubular cell regeneration, while maladaptive repair increases the risk of progression to chronic kidney disease. Fundamental management strategies include early sepsis recognition and prompt treatment, through the administration of adequate antimicrobial agents, fluid resuscitation, and vasoactive agents as needed. In septic patients, organ-specific support is often required, particularly renal replacement therapy (RRT) in the setting of severe AKI, although ongoing debates persist regarding the ideal timing of initiation and dosing of RRT. A comprehensive approach integrating early recognition, targeted interventions, and close monitoring is essential to mitigate the burden of SA-AKI and improve patient outcomes in critical care settings.
Assuntos
Injúria Renal Aguda , Sepse , Humanos , Injúria Renal Aguda/terapia , Injúria Renal Aguda/etiologia , Sepse/complicações , Sepse/terapia , Terapia de Substituição Renal/métodos , Estado TerminalRESUMO
Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape, and morphology offer a sustainable solution to the water pollution problem by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigated the influence of pore and particle sizes of photocatalytic MICROSCAFS® on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica-titania microspheres with a controlled size and interconnected macroporosity, synthesized by an adapted sol-gel method that involves a polymerization-induced phase separation process. Photocatalytic experiments were performed both in batch and flow reactors, with this latter one targeting a proof of concept for continuous transformation processes and real-life conditions. Photocatalytic degradation of 87% in 2 h (batch) was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® performance. A scavenger study was performed, enabling an in-depth mechanistic understanding. Finally, the transformation products resulting from the MO photocatalytic degradation were elucidated by high-resolution mass spectrometry experiments and subjected to an in silico toxicity assessment.
Assuntos
Compostos Azo , Luz Solar , Titânio , Poluentes Químicos da Água , Purificação da Água , Catálise , Purificação da Água/métodos , Titânio/química , Poluentes Químicos da Água/química , Porosidade , Compostos Azo/química , Microesferas , Dióxido de Silício/química , Fotólise , Cinética , Processos FotoquímicosRESUMO
Palm seedlings are visually selected from mature fruits in a slow process that leads to nonuniform germination and high embryo mortality. In this study, we determined the levels of monosaccharides, their crystallinity, and their role in the formation of Euterpe edulis endosperm during seed maturation. Seeds harvested from 108 to 262 days after anthesis (DAA) were analyzed morphologically, physiologically, and chemically to measure soluble and insoluble lignins, ashes, structural carbohydrates, degree of crystallinity, and endo-ß-mannanase. The seeds achieved maximum germination and vigor at 164 DAA. During the early stages, only compounds with a low structural order were formed. The contents of soluble and insoluble lignins, ashes, glucans, and galactans decreased during maturation. Those of mannans, the main structural carbohydrate in the endosperm, increased along with the degree of crystallinity, as suggested by a mannan-I-type X-ray diffraction pattern. Similarly, endo-ß-mannanase activity peaked at 262 DAA. The superior physiological outcome of seeds and seedlings at 164 DAA implies a 98-day shorter harvesting time. The state of mannans during seed maturation could be used as a marker to improve seedling production by E. edulis.
Assuntos
Arecaceae , Germinação , Mananas , Sementes , Sementes/crescimento & desenvolvimento , Sementes/química , Mananas/química , Arecaceae/química , Arecaceae/crescimento & desenvolvimento , Árvores , Lignina/química , Lignina/metabolismo , Endosperma/química , Endosperma/metabolismo , Plântula/crescimento & desenvolvimentoRESUMO
A characteristic feature of ionic liquids is their nanosegregation, resulting in the formation of polar and nonpolar domains. The influence of increasing the alkyl side chain on the morphology of ionic liquids has been the subject of many studies. Typically, the polar network (charged part of the cation and anion) constitutes a continuous subphase that partially breaks to allow the formation of a nonpolar domain with the increase of the alkyl chain. As the nonpolar network expands, the number of tails per aggregate increases until the ionic liquid percolates. In this work, we demonstrate how the complementary software packages TRAVIS and AGGREGATES can be employed in conjunction to gain insights into the size and morphology of the [CnC1Im]Cl family, with n ∈ {2, 4, 6, 8, 10, 12}. The combination of the two approaches rounds off the picture of the intricate arrangement and structural features of the alkyl chains.
RESUMO
INTRODUÇÃO: As doenças cardiovasculares (DCVs) são as principais responsáveis pelas mortes no mundo desde o último século, sendo o infarto agudo do miocárdio (IAM) a causa isolada de maior dsetaque, muitas vezes em virtude da dificuldade diagnóstica. A incorporação de novas tecnologias com uso de Inteligência Artificial (AI) surge como potencial aliada neste cenário. OBJETIVO: O objetivo do presente estudo foi desenvolver um modelo de Redes Neurais Artificiais (RNAs) com a utilização de imagens de eletrocardiogramas (ECGs) e a extração dos sinais com alta sensibilidade e especificidade em relação aos laudos médicos para a identificação de casos de IAM com elevação do segmento ST (IAMCST). MÉTODOS: O modelo foi treinado com dados de 3.768 exames de janeiro a dezembro de 2022, totalizando 17.567 derivações. Do total, 820 eram exames com IAMCST e 2.948 sem IAMCST. Foram separados 90% dos dados para treino e 10% para teste. A arquitetura da rede utilizada foi baseada na ResNet de uma dimensão com uma camada de convolução inicial, quatro blocos de camadas residuais e um bloco de camada densa para classificação binária. O sinal foi filtrado, padronizado com mediana igual a 0 e desvio padrão igual a 1 e utilizado padding para padronização de tamanho dentre todas as derivações. Como forma de aumentação de dados, com objetivo de fornecer a rede mais dados para aprender sobre IAMCST, foi realizado um filtro SavGol nos sinais, o que fez com que se obtivesse o dobro de sinais originais das imagens, para entrada no modelo neural. Ainda que a IA tenha sido treinada com as derivações, a acurácia foi mensurada por exame. Resultados: O modelo obteve, ao final, uma sensibilidade de 97%, especificidade de 69% e área sob a curva ROC de 92% para a predição de IAMCST por exame. Tal resultado foi um ganho para o uso das redes neurais, visto que a tecnologia anteriormente utilizada, apenas com a extração das métricas das ondas, apresentou acurácia inferior. CONCLUSÃO: Concluímos que os modelos de RNA, que extraem sinais das imagens e os transformam em predições para auxílio na tomada de decisão de médicos, podem ser incluídos no arsenal de métodos preditivos para triagem de IAMCST, com elevada sensibilidade.
Assuntos
Redes Neurais de Computação , DiagnósticoRESUMO
In this initial study, the impact of thermosonication as an alternative to the traditional fusion in Brazilian cheese spread (Requeijão Cremoso) manufacture was investigated. The effect of ultrasound (US) power was evaluated considering various aspects such as gross composition, microstructure, texture, rheology, color, fatty acid composition, and volatile compounds. A 13 mm US probe operating at 20 kHz was used. The experiment involved different US power levels (200, 400, and 600 W) at 85 °C for 1 min, and results were compared to the conventional process in the same conditions (85 °C for 1 min, control treatment). The texture became softer as ultrasound power increased from 200 to 600 W, which was attributed to structural changes within the protein and lipid matrix. The color of the cheese spread also underwent noticeable changes for all US treatments, and treatment at 600 W resulted in increased lightness but reduced color intensity. Moreover, the fatty acid composition of the cheese spread showed variations with different US power, with samples treated at 600 W showing lower concentrations of saturated and unsaturated fatty acids, as well as lower atherogenicity and thrombogenicity indexes, indicating a potentially healthier product. Volatile compounds were also influenced by US, with less compounds being identified at higher powers, especially at 600 W. This could indicate possible degradation, which should be evaluated in further studies regarding US treatment effects on consumer perception. Hence, this initial work demonstrated that thermosonication might be interesting in the manufacture of Brazilian cheese spread, since it can be used to manipulate the texture, color and aroma of the product in order to improve its quality parameters.
Assuntos
Queijo , Queijo/análise , Sonicação/métodos , Brasil , Manipulação de Alimentos/métodos , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análise , Ácidos Graxos/química , Cor , TemperaturaRESUMO
In Santa Quitéria City, part of the population uses surface water for potation. These waters do not undergo any treatment before consumption. As the region has a deposit of uranium, assessing water quality becomes important. In the present study, the uranium activity concentration (AC) in becquerels per liter was determined in water samples from six points. Univariate statistics showed differences between the soluble and the particulate fraction (soluble AC > particulate AC). The particulate fraction showed no variation in AC among the six points. On the other hand, the soluble fraction and the total fraction presented different ACs between them. The multivariate statistics allowed to separate the soluble from the particulate fraction of the points. The same tools applied to the total fraction made it possible to differentiate the sampling points, grouping them ((#1, #2); (#3, #4), and (#5, #6)). The maximum mean value of AC found was 0.177 BqâL-1, corresponding to 25% of the chemical toxicity limit (0.72 BqâL-1). The maximum mean dose rate, 2.25 µSvâyear-1, is lower than the considered negligible dose rate (> 10 µSvâyear-1). The excess lifetime cancer risk was 10-6, two orders of magnitude smaller than the threshold considered for taking action. The assessment parameters used in this work indicate that the risk due to the uranium intake by the local population is negligible.
Assuntos
Urânio , Urânio/análise , Brasil , Poluentes Radioativos da Água/análise , Humanos , Monitoramento de RadiaçãoRESUMO
OBJECTIVE: To evaluate the effects of Lower Extremity - Constraint Induced Movement Therapy on gait function and balance in chronic hemiparetic patients. METHODS: Randomized, controlled, single-blinded study. We recruited chronic post stroke patients and allocated them to Lower Extremity - Constraint Induced Movement Tharapy (LE-CIMT) or Control Group. The LE-CIMT group received this protocol 2.5 hour/day for 15 followed days, including: 1) intensive supervised training, 2) use of shaping as a strategy for motor training, and 3) application of a transfer package. The control group received conventional physiotherapy for 2.5 hours/day for 15 followed days. Outcomes were assessed at baseline, after the interventions, and after 6 months, through 6-minute walk test and Mini-Balance Evaluation Systems Test; 10-meter walk test, Timed Up and Go, 3-D gait analysis, and Lower Extremity - Motor Activity Log. RESULTS: LE-CIMT was superior on the Assistance and confidence subscale of Lower Extremity - Motor Activity Log, Mini-BESTest and 6-minute walk test. The effect size for all outcomes was small when comparing both groups. LE-CIMT showed clinically significant differences in daily activities, balance, and gait capacity, with no clinically significant difference for spatiotemporal parameters. CONCLUSION: The LE-CIMT protocol had positive outcomes on balance, performance, and confidence perception.
Assuntos
Extremidade Inferior , Equilíbrio Postural , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Reabilitação do Acidente Vascular Cerebral/métodos , Equilíbrio Postural/fisiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Idoso , Método Simples-Cego , Extremidade Inferior/fisiopatologia , Resultado do Tratamento , Marcha/fisiologia , Terapia por Exercício/métodos , Recuperação de Função Fisiológica/fisiologia , Transtornos Neurológicos da Marcha/reabilitação , Transtornos Neurológicos da Marcha/etiologia , Transtornos Neurológicos da Marcha/fisiopatologia , Adulto , Doença CrônicaRESUMO
Progesterone-related diabetes mellitus (PRDM) in dogs is known for its particular potential for diabetes remission. This narrative review aims to provide relevant detailed information on (1) the canine estrus cycle and its impact on canine diabetes mellitus (CDM) etiology and management, (2) the role of pyometra as a further cause of insulin resistance, and (3) useful individual therapeutic and preventive strategies. PRDM is recognized due to diestrus, exogenous progestogen exposure, pregnancy, and P4-production ovarian dysfunction. Pyometra represents additional inflammatory and septic negative influence on insulin sensitivity, and its diagnosis associated with CDM is therapeutically challenging. The estrus cycle's hormone fluctuations seem to modulate peripheric insulin sensibility by influencing insulin receptor (IR) affinity and its binding capacity, as well as modulating tyrosine kinase activity. Pyometra was shown to negatively influence IR compensatory mechanisms to insulin resistance causing glucose intolerance. Spaying and pregnancy termination may cause diabetes remission in PRDM cases in a median time of 10 days (1-51). Pharmacological annulment of progesterone effects may benefit patients unable to undergo surgery; however, remission chances are virtually null. The ALIVE (Agreeing Language in Veterinary Endocrinology) project proposed new criteria for CDM diagnoses and subclinical diabetes recognition. These new concepts may increase the frequency of a PRDM diagnosis and, even more, its relevance. Spaying represents a preventive measure against pyometra and PRDM that should be individually assessed in light of its recognized benefits and harms.
RESUMO
The unique physicochemical properties of ionic liquids (ILs) attracted interest in their application as lubricants of micro/nano-electromechanical systems. This work evaluates the feasibility of using the protic ionic liquids [4-picH][HSO4], [4-picH][CH3SO3], [MIMH][HSO4], and [MIMH][CH3SO3] and the aprotic ILs [C6mim][HSO4] and [C6mim][CH3SO3] as additives to model lubricant poly(ethylene glycol) (PEG200) to lubricate silicon surfaces. Additives based on the cation [4-picH]+ exhibited the best tribological performance, with the optimal value for 2% [4-picH][HSO4] in PEG200 (w/w). Molecular dynamics (MD) simulations of the first stages of adsorption of the ILs at the glass surface were performed to portray the molecular behavior of the ILs added to PEG200 and their interaction with the silica substrate. For the pure ILs at the solid substrates, the MD results indicated that weak specific interactions of the cation with the glass interface are lost to accommodate the larger anion in the first contact layer. For the PEG200 + 2% [4-picH][HSO4] system, the formation of a more compact protective film adsorbed at the glass surface is revealed by a larger trans population of the dihedral angle -O(R)-C-C-O(R)- in PEG200, in comparison to the same distribution for the pure model lubricant. Our findings suggest that the enhanced lubrication performance of PEG200 with [4-picH][HSO4] arises from synergistic interactions between the protic IL and PEG200 at the adsorbed layer.
RESUMO
The Golgi Reassembly and Stacking Proteins (GRASPs) are engaged in various functions within the cell, both in unconventional secretion mechanisms and structuring and organizing the Golgi apparatus. Understanding their specific role in each situation still requires more structural and functional data at the molecular level. GRASP55 is one of the GRASP members in mammals, anchored to the membrane via the myristoylation of a Gly residue at its N-terminus. Therefore, co-translational modifications, such as myristoylation, are fundamental when considering a strategy to obtain detailed information on the interactions between GRASP55 and membranes. Despite its functional relevance, the N-terminal myristoylation has been underappreciated in the studies reported to date, compromising the previously proposed models for GRASP-membrane interactions. Here, we investigated the synergy between the presence of the membrane and the formation of oligomeric structures of myristoylated GRASP55, using a series of biophysical techniques to perform the structural characterization of the lipidated GRASP55 and its interaction with biological lipid model membranes. Our data fulfill an unexplored gap: the adequate evaluation of the presence of lipidations and lipid membranes on the structure-function dyad of GRASPs.Communicated by Ramaswamy H. Sarma.
RESUMO
Uranium mining can cause environmental impacts on non-human biota around mine sites. Because of this, the reduction in non-human biota exposure becomes an important issue. Environmental radioprotection results from the evolution of human radioprotection; it is based on dose rate to non-human biota and uses, as a biological target, and has harmful effects on populations. In the present study, a flooded impoundment created following dam construction in a uranium mine plant undergoing decommissioning was investigated. Internal dose rates due to activity concentration of natural uranium (Unat) and 232Th in omnivorous, phytophagous, and carnivorous fish species were estimated. Radionuclide activity concentrations were obtained by spectrophotometry with arsenazo III in the visible range. The dose rate contribution of 232Th was lower than that of Unat. There were no differences between the internal dose rates to studied fish species due to 232Th, but there were differences for Unat. A dose rate of 2.30·10-2 µGyâd-1 was found due to the two studied radionuclides. Although this value falls below the benchmark for harmful effects, it is important to acknowledge that the assessment did not account for other critical radionuclides from uranium mining, which also contribute to the internal dose. Moreover, the study did not assess external doses. As a result, the possibility cannot be excluded that dose rates at the study area overcome the established benchmarks for harmful effects.
Assuntos
Monitoramento de Radiação , Urânio , Poluentes Radioativos da Água , Animais , Tório/análise , Urânio/análise , Brasil , Radioisótopos , Poluentes Radioativos da Água/análiseRESUMO
OBJECTIVE: To evaluate the temporal trend of bronchopulmonary dysplasia (BPD) in preterm infants who survived to at least 36 weeks' post-menstrual age (PMA) and BPD or death at 36 weeks' PMA, and to analyse variables associated with both outcomes. DESIGN: Retrospective cohort with data retrieved from an ongoing national registry. SETTING: 19 Brazilian university public hospitals. PATIENTS: Infants born between 2010 and 2019 with 23-31 weeks and birth weight 400-1499 g. MAIN OUTCOME MEASURES: Temporal trend was evaluated by Prais-Winsten model and variables associated with BPD in survivors or BPD or death were analysed by logistic regression. RESULTS: Of the 11 128 included infants, BPD in survivors occurred in 22%, being constant over time (annual per cent change (APC): -0.80%; 95% CI: -2.59%; 1.03%) and BPD or death in 45%, decreasing over time (APC: -1.05%; 95% CI: -1.67%; -0.43%). Being male, small for gestational age, presenting with respiratory distress syndrome, air leaks, needing longer duration of mechanical ventilation, presenting with treated patent ductus arteriosus and late-onset sepsis were associated with an increase in the chance of BPD. For the outcome BPD or death, maternal bleeding, multiple gestation, 5-minute Apgar <7, late-onset sepsis, necrotising enterocolitis and intraventricular haemorrhage were added to the variables reported above as increasing the chance of the outcome. CONCLUSION: The frequency of BPD in survivors was constant and BPD or death decreased by 1.05% at each study year. These results show some improvement in perinatal care in Brazilian units which resulted in a reduction of BPD or death, but further improvements are still needed to reduce BPD in survivors.
RESUMO
In an effort to develop efficient vaccine formulations, the use of ordered mesoporous silica (SBA-15) as an antigen carrier has been investigated. SBA-15 has required properties such as high surface area and pore volume, including narrow pore size distribution to protect antigens inside its matrix. This study aimed to examine the impact of solvent removal methods, specifically freeze-drying and evaporation on the intrinsic properties of an immunogenic complex. The immunogenic complexes, synthesized and incorporated with BSA, were characterized by various physicochemical techniques. Small Angle X-ray Scattering measurements revealed the characteristic reflections associated to pure SBA-15, indicating the preservation of the silica mesostructured following BSA incorporation and the formation of BSA aggregates within the macropore region. Nitrogen Adsorption Isotherm measurements demonstrated a decrease in surface area and pore volume for all samples, indicating that the BSA was incorporated into the SBA-15 matrix. Fluorescence spectroscopy evidenced that the tryptophan residues in BSA inside SBA-15 or in solution displayed similar spectra, showing the preservation of the aromatic residues' environment. The Circular Dichroism spectra of BSA in both conditions suggest the preservation of its native secondary structure after the encapsulation process. The immunogenic analysis with the detection of anti-BSA IgG did not give any significant difference between the non-dried, freeze-dried or evaporated groups. However, all groups containing BSA and SBA-15 showed results almost three times higher than the groups with pure BSA (control group). These facts indicate that none of the BSA incorporation methods interfered with the immunogenicity of the complex. In particular, the freeze-dried process is regularly used in the pharmaceutical industry, therefore its adequacy to produce immunogenic complexes was proved Furthermore, the results showed that SBA-15 increased the immunogenic activity of BSA.