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1.
Food Chem ; 405(Pt A): 134751, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36347205

RESUMO

A 3D Fe3O4@MWCNT-CdIIP was synthesized by the oxidizing surface of multi-walled carbon nanotubes with carboxylic acid end groups and its subsequent termination with an ion imprinted polymer. An artificial neural network manifests better predictability than the central composite design methodology for optimising the adsorption procedure. The adsorption capacity was 109 mg g-1 (2.5 times more than non-imprinted polymer) under optimized conditions (pH; 5.6, time; 15 min, concentration; 800 µg mL-1 temperature; 25 °C), which was in accord with Toth isotherm. Fractal-like pseudo-second-order kinetics was found reasonably fast, with 66 % adsorption in 5 min. Solid phase extraction coupled Flame atomic absorption spectrometry method provides selective recognition towards Cd(II), with limit of detection; 1.13 µg/L, limit of quantification; 3.21 µg/L after preconcentration (preconcentration factor; 50) and good robustness. The developed method was applied for Cd(II) determination in food (tea, coffee, bread, tobacco, radish, spinach), water and wastewater (>99 % removal as well). Cd(II) loaded IIP was further utilized to remove anionic dyes with >95 % removal.


Assuntos
Cádmio , Nanotubos de Carbono , Adsorção , Fenômenos Magnéticos , Nanotubos de Carbono/química , Polímeros/química , Extração em Fase Sólida/métodos , Análise de Alimentos
2.
Curr Opin Environ Sci Health ; : 100396, 2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36320818

RESUMO

Wastewater-Based Epidemiological Monitoring (WBEM) is an efficient surveillance tool during the COVID-19 pandemic as it meets all requirements of a complete monitoring system including early warning, tracking the current trend, prevalence of the disease, detection of genetic diversity as well asthe up-surging SARS-CoV-2 new variants with mutations from the wastewater samples. Subsequently, Clinical Diagnostic Test is widely acknowledged as the global gold standard method for disease monitoring, despite several drawbacks such as high diagnosis cost, reporting bias, and the difficulty of tracking asymptomatic patients (silent spreaders of the COVID-19 infection who manifest nosymptoms of the disease). In this current reviewand opinion-based study, we first propose a combined approach) for detecting COVID-19 infection in communities using wastewater and clinical sample testing, which may be feasible and effective as an emerging public health tool for the long-term nationwide surveillance system. The viral concentrations in wastewater samples can be used as indicatorsto monitor ongoing SARS-CoV-2 trends, predict asymptomatic carriers, and detect COVID-19 hotspot areas, while clinical sampleshelp in detecting mostlysymptomaticindividuals for isolating positive cases in communities and validate WBEM protocol for mass vaccination including booster doses for COVID-19.

3.
Vaccines (Basel) ; 10(9)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36146471

RESUMO

Q fever is caused by the bacterium Coxiella burnetii and is spread to humans from infected animals especially goats, sheep and cattle, predominantly when giving birth. There is an effective human vaccine (Q-VAX) against Q fever, and although Q fever is a worldwide problem, the vaccine is only used in Australia due to difficulties associated with its use and the risk of adverse reactions. The desire to protect humans, particularly farmers and abattoir workers, from Q fever prompted the development of a new safe and effective human vaccine without all the difficulties associated with the current vaccine. Candidate vaccines were prepared using purified O-specific polysaccharide (OSP) extracted from the lipopolysaccharide of virulent (phase 1) C. burnetii, strain Nine Mile, which was then conjugated to a tetanus toxoid (TT) carrier protein. Two vaccines were prepared using OSP from C. burnetii grown in embryonated eggs (vaccine A) and axenic media (vaccine B). Vaccines with or without alum adjuvant were used to vaccinate guinea pigs, which were later challenged by intranasal inoculation with virulent C. burnetii. Both vaccines protected guinea pigs from fever and loss of weight post challenge. Post-mortem samples of the spleen, liver and kidney of vaccinated guinea pigs contained substantially less C. burnetii DNA as measured by PCR than those of the unvaccinated control animals. This study demonstrated that a C. burnetii OSP-TT conjugate vaccine is capable of inducing protection against virulent C. burnetii in guinea pigs. Additionally, OSP derived from C. burnetii grown in axenic media compared to OSP from embryonated eggs is equivalent in terms of providing a protective immune response.

4.
Heliyon ; 8(8): e10229, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36033317

RESUMO

Newcastle disease (ND) is a real threat for commercial layer chicken farms in Bangladesh. However, only few studies have focused on exploring the epidemiology of this disease. A case-control study was conducted to identify determinants of Newcastle disease in commercial layer chicken farms in Kishoreganj and Gazipur district of Bangladesh between September 2019 and February 2020. Farms with birds diagnosed as ND positive based on clinical history, clinical signs and postmortem findings were considered as case and farms that did not have such ND positive chickens were the control for this study. Farmers of 56 case farms and 56 control farms were interviewed face to face using a structured questionnaire. The association between Farms' ND status and determinants was assessed by multivariable logistic regression with backward elimination. In the final model, six variables were found to be associated with the risk for ND outbreak: age of the farmers (Odds Ratio [OR] 0.94; 95% Confidence Interval [CI] 0.87-0.99), distance from the nearest poultry farms (OR = 3.23, 95% CI 1.27-8.39), number of houses in the farms (OR = 3.06, 95% CI 1.06-8.83), surrounding environments (OR = 5.27, 95% CI 1.96-14.20), rearing different aged bird together (OR = 4.76, 95% CI 1.25-18.19), and no isolation of sick birds (OR = 2.85, 95% CI 1.07-7.55). Alteration of these determinants should reduce the ND burden in commercial layer chicken farms.

5.
Environ Sci Pollut Res Int ; 29(45): 69068-69081, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35554830

RESUMO

A new Cd(II)-imprinting polymer was synthesised based on glycidyl methacrylate (Fe3O4@GMA@IIP) and employed to develop a dispersive magnetic solid-phase extraction method for the preconcentration prior to the determination of Cd(II) from the environmental samples. A central composite design (CCD) based on response surface methodology was used for optimization of the process variables and the material shows the promising saturation adsorption capacity of 28.21 mg g-1 under the optimum pH of 4.9 within 15.2 min at saturation concentration 914 µg mL-1. The experimental data were well described by Sips isotherm model and Brouers-Sotolongo fractal kinetic model that indicated the surface heterogeneity and involvement of both chemisorption and physisorption process. Thermodynamic results documented the endothermic and spontaneous nature of adsorption. The sorbent manifest the economic feasibility maintaining its sorption efficiency after the regeneration by 1 M HNO3 and reusability up to 6 adsorption/desorption cycles. The developed method exhibited the preconcentration factor of 30 and a high degree of tolerance for matrix ions. Limit of detection (LOD) and quantification (LOQ) were calculated as 3.054 and 10.182 µg L-1 respectively. The developed method was validated by the standard reference material and spiking addition method in real samples, and obtained results showed good agreement in accordance with spiking values. The ease of magnetic separation, high selectivity, good adsorption capacity and faster kinetics made this material a promising candidate for Cd(II) determination in various food and aqueous samples.


Assuntos
Impressão Molecular , Polímeros , Adsorção , Cádmio , Compostos de Epóxi , Íons , Metacrilatos , Espectrofotometria Atômica
6.
J Bacteriol ; 204(6): e0003222, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35604222

RESUMO

The opportunistic pathogen A. baumannii has a remarkable capacity to persist in the hospital environment and cause devastating human infections. This capacity can be attributed partly to the sensing and regulatory systems that enable this pathogen to modify its physiology based on environmental cues. One of the signals that A. baumannii senses and responds to is light through the sensing and regulatory roles of the BlsA photoreceptor protein in cells cultured at temperatures below 30°C. This report presents evidence that a light stimulon is operational at 37°C, a condition at which the BlsA production and activity are drastically impaired. Global transcriptional analysis showed that the 37°C light stimulon includes the differential expression of chromosomal genes encoding a wide range of functions that are known to be involved in the adaptation to different metabolic conditions, as well as virulence and persistence in the host and the medical environment. Unexpectedly, the 37°C light stimulon also includes the differential expression of conjugation functions encoded by pAB3 plasmid genes. Our work further demonstrates that the TetR1 and H-NS regulators encoded by this conjugative plasmid control the expression of H2O2 resistance and surface motility, respectively. Furthermore, our data showed that pAB3 has an overall negative effect on the expression of these phenotypes and plays no significant virulence role. Although the nature of the bacterial factors and the mechanisms by which the regulation is attained at 37°C remain unknown, taken together, our work expands the current knowledge about light sensing and gene regulation in A. baumannii. IMPORTANCE As a facultative pathogen, Acinetobacter baumannii persists in various environments by sensing different environmental cues, including light. This report provides evidence of light-dependent regulation at 37°C of the expression of genes coding for a wide range of functions, including those involved in the conjugation of the pAB3 plasmid. Although this plasmid affects the expression of virulence traits when tested under laboratory conditions, it does not have a significant impact when tested using ex vivo and in vivo experimental models. These findings provide a better understanding of the interplay between light regulation and plasmid persistence in the pathobiology of A. baumannii.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , Peróxido de Hidrogênio/metabolismo , Plasmídeos/genética , Temperatura , Virulência/genética
7.
Micromachines (Basel) ; 13(4)2022 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-35457820

RESUMO

The metallization of plastics is an important industrial process. Plastics are metallized for both aesthetic and functional purposes. The unceasing pursuit towards the miniaturization and reduction in the part's size challenges the already complicated process of metallization. A rigorous research study uncovering the effects of miniaturization on the quality of metallized parts is missing at the state-of-the-art level. This study focuses on the quality of the deposited metal film based on geometrical dimensions and systematically characterizes the effects of miniaturization on the metallized micro-components. The experimental results presented in this paper reveal the hidden synergy among the metallization quality, part dimension, and process conditions used both for substrate fabrication and for metallization. The paper broadens the fundamental understanding about the interactions of various design, materials, and process parameters involved in the manufacturing process chain. The results and discussions presented in this paper will be valuable sources of information to deal with the integration of micrometallic structures on polymeric substrates for high precision applications.

8.
Biomed Res Int ; 2022: 2805402, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35372570

RESUMO

Eye temperature and intraocular pressure are two measurable parameters that can be monitored as a health index with aging. Deviations from the normal range of intraocular pressure and temperature lead to the formation of many diseases. This study has been carried out to evaluate the relations between the physiological and anatomical changes of the eye with aging using mathematical modeling. 2D computer-aided design of the human eye has been developed for two major groups: 21 to 30 years and 41 to 50 years. The computer simulation has been carried out to determine the effects of physiological changes of tear evaporation, fluid dynamics, blood flow, and metabolism of eye tissues with aging. The simulation has been carried out in the standing and the supine position of a human body. The rate of temperature change is - 0.0075 K per year in the standing position and - 0.007 K per year in the supine position because of the modeled anatomical and physiological effects. All the three simulation parameters of this study, the temperature of the human eye, the intraocular pressure, and the aqueous humor flow velocity, have been compared with the recent practical and simulation-based experiments to validate our results.


Assuntos
Humor Aquoso , Hidrodinâmica , Envelhecimento , Humor Aquoso/fisiologia , Simulação por Computador , Humanos , Pressão Intraocular
9.
Nat Commun ; 13(1): 367, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35042893

RESUMO

Tomographic volumetric printing (TVP) physically reverses tomography to offer fast and auxiliary-free 3D printing. Here we show that wavelength-sensitive photoresins can be cured using visible ([Formula: see text] nm) and UV ([Formula: see text] nm) sources simultaneously in a TVP setup to generate internal mechanical property gradients with high precision. We develop solutions of mixed acrylate and epoxy monomers and utilize the orthogonal chemistry between free radical and cationic polymerization to realize fully 3D stiffness control. The radial resolution of stiffness control is 300 µm or better and an average modulus gradient of 5 MPa/µm is achieved. We further show that the reactive transport of radical inhibitors defines a workpiece's shape and limits the achievable stiffness contrast to a range from 127 MPa to 201 MPa according to standard tensile tests after post-processing. Our result presents a strategy for controlling the stiffness of material spatially in light-based volumetric additive manufacturing.

10.
J Biomed Res ; 35(6): 459-473, 2021 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34857680

RESUMO

Lassa hemorrhagic fever, caused by Lassa mammarenavirus (LASV) infection, accumulates up to 5000 deaths every year. Currently, there is no vaccine available to combat this disease. In this study, a library of 200 bioactive compounds was virtually screened to study their drug-likeness with the capacity to block the α-dystroglycan (α-DG) receptor and prevent LASV influx. Following rigorous absorption, distribution, metabolism, and excretion (ADME) and quantitative structure-activity relationship (QSAR) profiling, molecular docking was conducted with the top ligands against the α-DG receptor. The compounds chrysin, reticuline, and 3-caffeoylshikimic acid emerged as the top three ligands in terms of binding affinity. Post-docking analysis revealed that interactions with Arg76, Asn224, Ser259, and Lys302 amino acid residues of the receptor protein were important for the optimum binding affinity of ligands. Molecular dynamics simulation was performed comprehensively to study the stability of the protein-ligand complexes. In-depth assessment of root-mean-square deviation (RMSD), root mean square fluctuation (RMSF), polar surface area (PSA), B-Factor, radius of gyration (Rg), solvent accessible surface area (SASA), and molecular surface area (MolSA) values of the protein-ligand complexes affirmed that the candidates with the best binding affinity formed the most stable protein-ligand complexes. To authenticate the potentialities of the ligands as target-specific drugs, an in vivo study is underway in real time as the continuation of the research.

11.
Lupus ; 30(9): 1385-1393, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34000879

RESUMO

OBJECTIVE: Pruritus is an important symptom frequently accompanying various inflammatory skin conditions and some recent data indicated that it may be associated with autoimmune connective tissue diseases. The aim of this study was to assess the frequency and clinical presentation of itch in CLE. METHODS: A multinational, prospective, cross-sectional study was performed to assess the prevalence, intensity and clinical characteristic of pruritus in various subtypes of CLE. A total of 153 patients with active CLE lesions were included. Their age ranged between 17 and 82 years (mean 49.8 ± 15.4 years), and 115 patients (75.2%) were women. The disease activity and damage were assessed according to the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). Pruritus severity was assessed with Numeric Rating Scale (NRS) and the 12-Item Pruritus Severity Scale. Dermatology Life Quality Index and EQ-5D questionnaire were used to measure quality of life. RESULTS: Pruritus was present in 116 (76.8%) of patients of whom half had NRS scoring equal or above 4 points indicating moderate or severe pruritus. Most commonly itch was localized on the scalp, face (excluding ears and nose) and arms (40.5%, 36.2%, 31.9%, respectively). Sensations connected with pruritus were most frequently described as burning, tingling and like ants crawling feeling, but 31.9% patients described it as "pure itch". More than half of patients reported that pruritus was present every day, and it was most frequent during the evenings. The pruritus scoring and the CLASI activity score were significantly correlated (r = 0.42, p = 0.0001), while no correlation was found with the CLASI damage score (p = 0.16). Both the maximum and average itch intensity were correlated with systemic lupus erythematosus (SLE) activity measured with the Systemic Lupus Erythematosus Disease Activity Index. CONCLUSIONS: Pruritus is a common, but frequently overlooked symptom of CLE. Its intensity correlates with the activity of CLE, but not with the skin damage. In more than a half of patients it occurs on a daily basis. The correlation between the intensity of pruritus and the activity of the skin lesions and the systemic involvement indicate that pruritus could be an individual indicator of both SLE and CLE activity.


Assuntos
Lúpus Eritematoso Cutâneo , Prurido , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Lúpus Eritematoso Cutâneo/complicações , Lúpus Eritematoso Cutâneo/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Prurido/diagnóstico , Prurido/epidemiologia , Prurido/etiologia , Qualidade de Vida , Índice de Gravidade de Doença , Adulto Jovem
12.
Vet Immunol Immunopathol ; 236: 110253, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33940537

RESUMO

Coxiella burnetii causes Q fever in individuals exposed to infected ruminants. Vaccination in 3-4-month-old goats, has been reported to result in significantly greater reduction in C. burnetii shedding compared to goats vaccinated one month before breeding, the most commonly used strategy of controlling Q fever on infected intensively-managed herds. It is possible that an even greater reduction in the number of animals shedding C. burnetii could be achieved if vaccination were administered shortly after protection from colostrum antibodies wanes and animals become susceptible to infection with C. burnetii. This study aimed to evaluate the immunogenicity and safety of a formaldehyde-inactivated phase 1 C. burnetii vaccine in 8-week-old goats. Two injections, four weeks apart, elicited specific IgM and IgG responses in all vaccinated goats (n = 6), while no antibodies were detected in two control groups (n = 12). Swelling at the site of inoculation was observed in all the vaccinated and in 10/11 of the placebo-treated goats but receded after 3 weeks. Weight change and rectal temperatures were also comparable between vaccinated and control goats. The data indicated that this vaccine could be suitable for immunising 8-week-old goats, although further trials to determine level of protection against challenge are required.


Assuntos
Vacinas Bacterianas/imunologia , Formaldeído/química , Doenças das Cabras/prevenção & controle , Imunogenicidade da Vacina , Vacinação/veterinária , Fatores Etários , Animais , Antígenos de Bactérias/imunologia , Vacinas Bacterianas/administração & dosagem , Fezes/microbiologia , Feminino , Doenças das Cabras/imunologia , Doenças das Cabras/microbiologia , Cabras , Imuno-Histoquímica/métodos , Masculino , Gravidez , Distribuição Aleatória , Vacinas de Produtos Inativados/imunologia
13.
Front Plant Sci ; 12: 602052, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33833767

RESUMO

Decomposed organic materials, in combination with plant growth-promoting bacteria (PGPB), are environmentally friendly and reduce synthetic fertilizer use in rice production. A bio-organic fertilizer (BoF) was prepared using kitchen waste (79%), chita-dhan (unfilled rice grain) biochar (15%), rock phosphate (5%), and a consortium of 10 PGPB (1%) to supplement 30% nitrogen and to replace triple superphosphate (TSP) fertilizer in rice production with an improvement of soil health. PGPB were local isolates and identified using 16S ribosomal RNA partial gene sequences as Bacillus mycoides, Proteus sp., Bacillus cereus, Bacillus subtilis, Bacillus pumilus, Paenibacillus polymyxa, and Paenibacillus spp. Isolates could fix N2 by 0.7-1.4 g kg-1, solubilize 0.1-1.2 g kg-1 phosphate, and produce 0.1-40 g kg-1 indoleacetic acid. The performance of BoF was evaluated by 16 field experiments and 18 farmers' field demonstration trials during the year 2017-2020 in different parts of Bangladesh. Performances of BoF were evaluated based on control (T1), full synthetic fertilizer dose of N, P, and K (T2), BoF (2 t ha-1) + 70% N as urea + 100% K as muriate of potash (T3), 70% N as urea + 100% P as TSP + 100% K as muriate of potash (T4), and 2 t ha-1 BoF (T5) treatments. At the research station, average grain yield improved by 10-13% in T3 compared with T2 treatment. Depending on seasons, higher agronomic N use efficiency (19-30%), physiological N use efficiency (8-18%), partial factor productivity (PFP)N (114-150%), recovery efficiency (RE)N (3-31%), N harvest index (HIN) (14-24%), agronomic P use efficiency (22-25%), partial factor productivity of P (9-12%), AREP (15-23%), and HIP (3-6%) were obtained in T3 compared with T2 treatment. Research results were reflected in farmers' field, and significant (P < 0.05) higher plant height, tiller, panicle, grain yield, partial factor productivity of N and P were obtained in the same treatment. Application of BoF improved soil organic carbon by 6-13%, along with an increased number of PGPB as compared with full synthetic fertilizer dose. In conclusion, tested BoF can be considered as a green technology to reduce 30% synthetic N and 100% TSP requirements in rice production with improved soil health.

15.
Chemosphere ; 272: 129653, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33486455

RESUMO

The contamination of groundwater by arsenic (As) in Bangladesh is the biggest impairing of a population, with a large number of peoples affected. Specifically, groundwater of Gangetic Delta is alarmingly contaminated with arsenic. Similar, perilous circumstances exist in many other countries and consequently, there is a dire need to develop cost-effective decentralized filtration unit utilizing low-cost adsorbents for eliminating arsenic from water. Morphological synthesis of carbon with unique spherical, nanorod, and massive nanostructures were achieved by solvothermal method. Owing to their intrinsic adsorption properties and different nanostructures, these nanostructures were employed as adsorption of arsenic in aqueous solution, with the purpose to better understanding the morphological effect in adsorption. It clearly demonstrated that carbon with nanorods morphology exhibited an excellent adsorption activity of arsenite (about 82%) at pH 3, remarkably superior to the two with solid sphere and massive microstructures, because of its larger specific surface area, enhanced acid strength and improved adsorption capacity. Furthermore, we discovered that iron hydroxide radicals and energy-induced contact point formation in nanorods are the responsible for the high adsorption of As in aqueous solution. Thus, our work provides insides into the microstructure-dependent capability of different carbon for As adsorption applications.


Assuntos
Arsênio , Poluentes Químicos da Água , Purificação da Água , Adsorção , Arsênio/análise , Bangladesh , Carbono , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise
16.
ACS Nano ; 15(1): 1775-1784, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33448799

RESUMO

As graphene penetrates into industries, it is essential to mass produce high quality graphene sheets. New discoveries face formidable challenges in the marketplace due to the lack of proficient protocols to produce graphene on a commercial scale while maintaining its quality. Here, we present a conspicuous protocol for ultrafast exfoliation of graphite into high quality graphene on the sub-kilogram scale without the use of any intercalants, chemicals, or solvent. We show that graphite can be exfoliated using a plasma spray technique with high single-layer selectivity (∼85%) at a very high production rate (48 g/h). This is possible because of the inherent characteristics of the protocol which provides sudden thermal shock followed by two-stage shear. The exfoliated graphene shows almost no basal defect (Id/Ig: 0) and possesses high quality (C/O ratio: 21.2, sp2 %: ∼95%), an indication of negligible structural deterioration. The results were reproducible indicating the adeptness of the protocol. We provided several proofs-of-concept of plasma spray exfoliated graphene to demonstrate its utility in applications such as mechanical reinforcements; frictionless, transparent conductive coatings; and energy storage devices.

17.
Chemosphere ; 262: 127801, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32791366

RESUMO

In this study, cost-effective cellulosic biomass based activated wood charcoal was developed from Japanese Sugi tree (Cryptomeria japonica) by concentrated nitric acid modification for adsorption of Cs from contaminated water. The physicochemical properties of specimens were investigated using N2 adsorption-desorption isotherms (BET method), FESEM, FTIR, and XPS spectra analysis. The experimental results revealed that the surface area of the raw wood charcoal was significantly decreased after boiling nitric acid modification. However, several oxygen-containing acidic function groups (-COOH, -CO) were introduced on the surface. The adsorption study confirmed that the equilibrium contact time was 1 h, the optimum adsorption pH was neutral to alkaline and the suitable adsorbent dose was 1:100 (solid: liquid). The maximum Cs was removed when the concentration of Na and K were lower (5.0 mM) with Cs in solution. The Cs adsorption processes well approved by the Langmuir isotherm and pseudo-second-order kinetic models and the maximum adsorption capacity was 35.46 mgg-1. The Cs adsorption mechanism was clearly described and it was assumed that the adsorption was strongly followed by chemisorptions mechanism based on the adsorbent surface properties, kinetic model and Langmuir isotherm model. Most importantly, about 98% of volume reduction was obtained by burning (500 °C) the Cs adsorbed charcoal, which ensured safe storage and disposal of radioactive waste. Therefore, this study can offer a guideline to produce a functional adsorbent for effective Cs removal and safe radioactive waste disposal.


Assuntos
Césio/química , Poluentes Químicos da Água/química , Madeira/química , Adsorção , Biomassa , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Cinética , Ácido Nítrico , Propriedades de Superfície , Poluentes Químicos da Água/análise , Poluição da Água/análise
18.
Food Chem ; 334: 127563, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32791433

RESUMO

A new magnetic Cu(II) IIP (Fe3O4@IIP-IDC) is synthesized by polymerization of Imidazole-4,5-dicarboxylic acid functionalized Allyl chloride, and significant improvement of its performance has been compared. SPE parameters were optimized using Box-Behnken design to achieve the twin objectives of quantitative determination and removal of Cu(II). FLPSO kinetic model and BS isotherm model fits well with the capacity of 175 mg g-1. Analytical figures of merit includes a linearity range of 10-5,000 µg L-1 (R2 = 0.9986), preconcentration factor of 50 after eluting with 5 mL of 1 M HNO3, LOD of 1.03 µg L-1 and LOQ of 4.5 µg L-1. Accuracy was assessed by analysis of SRM (Standard Reference Material) and recovery experiments after spiking in food samples (Tea, coffee, chocolate, spinach, infant milk substitute) and battery wastewater. Ease of use, reusability (15 cycles), rapid adsorption and high selectivity makes it a promising candidate for efficient and selective removal and trace determination.


Assuntos
Cobre/análise , Análise de Alimentos/métodos , Impressão Molecular/métodos , Polímeros/química , Poluentes Químicos da Água/análise , Adsorção , Compostos Alílicos/química , Cobre/isolamento & purificação , Ácidos Dicarboxílicos/química , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Imidazóis/química , Limite de Detecção , Fenômenos Magnéticos , Poluentes Químicos da Água/isolamento & purificação
19.
Clin Infect Dis ; 73(9): e2560-e2568, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32761174

RESUMO

BACKGROUND: The Cholera Hospital-Based Intervention for 7 Days (CHoBI7) mobile health (mHealth) program was a cluster-randomized controlled trial of diarrhea patient households conducted in Dhaka, Bangladesh. METHODS: Patients were block-randomized to 3 arms: standard message on oral rehydration solution use; health facility delivery of CHoBI7 plus mHealth (no home visits); and health facility delivery of CHoBI7 plus 2 home visits and mHealth. The primary outcome was reported diarrhea in the past 2 weeks collected monthly for 12 months. The secondary outcomes were stunting, underweight, and wasting at a 12-month follow-up. Analysis was intention-to-treat. RESULTS: Between 4 December 2016 and 26 April 2018, 2626 participants in 769 households were randomly allocated to 3 arms: 849 participants to the standard message arm, 886 to mHealth with no home visits arm, and 891 to the mHealth with 2 home visits. Children <5 years had significantly lower 12-month diarrhea prevalence in both the mHealth with 2 home visits arm (prevalence ratio [PR]: 0.73 [95% confidence interval {CI}, .61-.87]) and the mHealth with no home visits arm (PR: 0.82 [95% CI, .69-.97]). Children <2 years were significantly less likely to be stunted in both the mHealth with 2 home visits arm (33% vs 45%; odds ratio [OR]: 0.55 [95% CI, .31-.97]) and the mHealth with no home visits arm (32% vs 45%; OR: 0.54 [95% CI, .31-.96]) compared with children in the standard message arm. CONCLUSIONS: The CHoBI7 mHealth program lowered pediatric diarrhea and stunting among diarrhea patient households. CLINICAL TRIALS REGISTRATION: NCT04008134.


Assuntos
Cólera , Telemedicina , Bangladesh/epidemiologia , Criança , Cólera/epidemiologia , Cólera/prevenção & controle , Diarreia/epidemiologia , Hospitais , Humanos , Higiene , Saneamento , Água
20.
J Environ Manage ; 300: 113782, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34560463

RESUMO

In this study, naturally abundant and inexpensive bamboo was used to make cheaper activated charcoal for efficient encapsulation of toxic copper (Cu(II)) ion from wastewater. The functionalized bamboo charcoal-Layered double hydroxides (BC-LDHs) composite bio-adsorbent was prepared using co-precipitation method. The composite bio-adsorbent was exploited to eliminate Cu(II) ion with high sensitivity and selectivity from contaminated water. The adsorption parameters including the effect of pH, contact time, adsorbent dose, and effect of initial concentration were optimized in systematic way and the adsorption kinetics and isotherms were investigated for potential use in real sample treatment. The physicochemical properties and morphological structure of the adsorbent were examined using X-ray Diffraction, Scanning Electronic Microscopy, Fourier Transform Infrared Spectroscopy and Thermogravimetric Analysis to understand the Cu(II) ion adsorption mechanism. The adsorption results revealed that the BC-LDH could remove almost 100% of Cu(II) ion from aqueous solution at pH range between 3.0 and 6.0 within 30 min. The maximum monolayer adsorption capacity was determined to be 85.47 mg/g based on the Langmuir isotherm. The adsorption equilibrium data were well-fitted by the Langmuir isotherm model (R2 = 0.998) and the experimental kinetic data were supported by the pseudo-second order model (R2 = 0.999). The BC-LDH could be reused without losing its adsorption performance in several cycles after successful regeneration with 0.10 M HCl. The Cu(II) ion removal mechanism was postulated with intercalated ion exchange, surface precipitation and interaction between BC-LDH and surface functionalities. Therefore, the highly functional BC-LDH composite could be a promising adsorbent for efficient Cu(II) ion removal from wastewater.


Assuntos
Poluentes Químicos da Água , Adsorção , Cobre , Concentração de Íons de Hidrogênio , Hidróxidos , Cinética , Poluentes Químicos da Água/análise
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