RESUMEN
Cationic synthetic dyes are one of the hazards in aqueous solutions that can affect the health of humans and living organisms. In the current work, polyacrylamide (PAM)-g-gelatin hydrogel and modified PAM-g-gelatin hydrogel using activated carbon of Luffa cylindrica (ACL) and ACL/Mg-Fe LDH were applied to eliminate crystal violet (CV), a cationic dye, from water media. The hydrogels were synthesized using free radical polymerization approach, and the hydrogels were characterized using FTIR, XRD, TGA-DTG, BET, SEM, and EDX-Map. The surface area of ACL, ACL/Mg-Fe LDH, PAM-g-gelatin, PAM-g-gelatin/ACL, and PAM-g-gelatin/ACL/Mg-Fe LDH were 99.71, 141.99, 0.74, 1.47, and 1.65 m2/g, respectively, which shows that the presence of ACL and ACL/Mg-Fe LDH improved the area of the hydrogels. The maximum abatement of CV using PAM-g-gelatin (92.81%), PAM-g-gelatin/ACL (95.71%), and PAM-g-gelatin/ACL/Mg-Fe LDH (98.25%) was obtained at pH = 9, temperature 25 °C, 10 mg/L CV, 60 min time, and adsorber dose of 2 g/L (for PAM-g-gelatin) and 1.5 g/L (other samples). The value of thermodynamic factors confirmed that the abatement process is exothermic and spontaneous. The kinetics data followed the pseudo-second kinetic (PSO) model. The Langmuir isotherm model had a more remarkable ability to describe the equilibrium data. The maximum adsorption capacity for PAM-g-gelatin, PAM-g-gelatin/ACL, and PAM-g-gelatin/ACL/Mg-Fe LDH was determined 35.45, 39.865, and 44.952 mg/g, respectively. Generally, the studied hydrogels can eliminate dyes from wastewater and be used as effective adsorbers.
Asunto(s)
Resinas Acrílicas , Gelatina , Violeta de Genciana , Hidrogeles , Resinas Acrílicas/química , Gelatina/química , Violeta de Genciana/química , Hidrogeles/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis , Colorantes/química , AdsorciónRESUMEN
Background: Systemic sclerosis is an autoimmune disease characterised by endothelial dysfunction and fibrosis of the skin and internal organs. Cardiac involvement during systemic sclerosis can be primary or secondary to pulmonary arterial hypertension and renal pathology. Among the disorders in systemic sclerosis, prolongation of QTc time is also associated with more anti-RNA polymerase III antibodies, longer duration, and severity of disease. Methods: This case-control study was performed on 35 patients with systemic scleroderma who filled in the American Society of Rheumatism (ACR / EULAR criteria) and 35 healthy subjects prior to entering the study. Then, the QTc distance was extracted from the electrocardiogram and calculated using the formula. The measured QTc distance in the electrocardiogram, QTc> 440ms in men and QTc> 460ms in women, was defined as QTc long. The patients and the control group then underwent echocardiography, and changes in QTc interval and their relations with echocardiographic findings were evaluated. Results: The results of this study indicated a significant relationship between QTc distance in patients with scleroderma compared with healthy controls. There was also a significant relationship between QTc and Skin Score of patients. However, there was no significant correlation between QTc distance and age, duration of disease, Anti-Centromere, Anti-Scl70, and pulmonary artery pressure. Conclusion: This study concludes that patients with scleroderma are at high risk for cardiac conduction impairment. The only factor that significantly correlated with QTc was the Skin Score of the patients.
RESUMEN
A novel magnetic adsorbent based on hydrolyzed Luffa Cylindrica (HLC) was synthesized through the chemical co-precipitation technique, and its potential was evaluated in the adsorptive elimination of divalent nickel ions from water medium. Morphological assessment and properties of the adsorbent were performed using FTIR, SEM, EDX, XRD, BET, and TEM techniques. The effect of pH, temperature, time and nickel concentration on the removal efficiency was studied, and pH = 6, room temperature (25 °C), contact time of 60 min, and Ni2+ ion concentration of 10 mg.L-1 were introduced as the optimal values. At optimal conditions, the removal efficiency of Ni2+ ions using HLC and HLC/CoFe2O4 magnetic composite was calculated as 96.38 and 99.13%, respectively. The adsorption process kinetic followed a pseudo-first-order model. Langmuir isotherm was suitable for modelling the experimental data of the Ni2+ adsorption. The maximum elimination capacity of HLC and HLC/CoFe2O4 samples was calculated as 42.75 and 44.42 mg g-1, respectively. Furthermore, thermodynamic investigations proved the spontaneous and exothermic nature of the process. The adsorption efficiency was decreased with increasing the content of Ca2+ and Na + cations in aqueous media. During reusability of the synthesized adsorbents, it was found that after 8 cycles, no significant decrease has occurred in the adsorption efficiency. In addition, real wastewater treatment results proved that HLC/CoFe2O4 magnetic composite has an excellent performance in removal of heavy metals pollutant from shipbuilding effluent.
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Luffa , Nanopartículas , Contaminantes Químicos del Agua , Adsorción , Cobalto , Compuestos Férricos , Concentración de Iones de Hidrógeno , Iones , Cinética , Níquel , Termodinámica , Aguas Residuales/química , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
Natural polysaccharides are attractive materials for fabrication of eco-friendly biodsorbents for efficient water remediation. However, scarcity of adsorbents that possess features of high stability and adsorption capacity at various pH conditions, low-cost, eco-friendly, and recycleability at the same time still remains a great challenge. Herein, porous ionically crosslinked biofoams were prepared by freeze-drying of chitosan (CS)/sodium alginate (SA) complex (CSA). FTIR and XRD were used to characterize the structure of the bioadsorbents. SEM observations revealed that adsorbents have a 3D interconnected porous structure, which is a favorable morphology for dye adsorption. Accordingly, CSA and its nanocomposite containing 15â¯wt% cellulose nanofibers (CSAC15) exhibited a fast and efficient adsorption behavior with qm values of 2015 and 2297â¯mg/g for adsorption of the Eriochrome black-T (EBT) anionic dye, respectively, which are quite outstanding among the developed EBT adsorbents in the literature so far. The CSAC15 preserved its stability and high adsorption capacity at various pH solutions. The adsorption of EBT onto the bioadsorbents was well-described with the pseudo-second order kinetics and Freundlich isotherm. The proposed CSAC15 bioadsorbent featured repeated dye removal capability after five cycles of adsorption.
Asunto(s)
Alginatos/química , Compuestos Azo/aislamiento & purificación , Celulosa/química , Quitosano/química , Nanofibras/química , Adsorción , Compuestos Azo/química , Colorantes/química , Colorantes/aislamiento & purificación , Humanos , Concentración de Iones de Hidrógeno , Cinética , Microscopía Electrónica de Rastreo/métodos , Nanocompuestos/química , Porosidad , Reciclaje , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Termodinámica , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Difracción de Rayos X/métodosRESUMEN
Background/Purpose. In terms of the detection of tooth diagnosis, no intelligent detection has been done up till now. Dentists just look at images and then they can detect the diagnosis position in tooth based on their experiences. Using new technologies, scientists will implement detection and repair of tooth diagnosis intelligently. In this paper, we have introduced one intelligent method for detection using particle swarm optimization (PSO) and our mathematical formulation. This method was applied to 2D special images. Using developing of our method, we can detect tooth diagnosis for all of 2D and 3D images. Materials and Methods. In recent years, it is possible to implement intelligent processing of images by high efficiency optimization algorithms in many applications especially for detection of dental caries and restoration without human intervention. In the present work, we explain PSO algorithm with our detection formula for detection of dental caries and restoration. Also image processing helped us to implement our method. And to do so, pictures taken by digital radiography systems of tooth are used. Results and Conclusion. We implement some mathematics formula for fitness of PSO. Our results show that this method can detect dental caries and restoration in digital radiography pictures with the good convergence. In fact, the error rate of this method was 8%, so that it can be implemented for detection of dental caries and restoration. Using some parameters, it is possible that the error rate can be even reduced below 0.5%.
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INTRODUCTION: Coverage of bone grafts is very important in reconstructive surgery. In edentulous alveolar ridges this coverage is particularly important for supporting dental prostheses. Here we present the case of a patient with a large deficient maxillary anterior region that was reconstructed with a bilateral palatal submucosal periosteal connective tissue flap: a soft tissue reserve for upper jaw reconstructive surgeries. The bilateral pediculated palatal periosteal connective tissue flap was used for coverage of a large bone graft in the anterior maxillary region. CONCLUSION: Palatal submucosa can be used as a soft tissue reserve in upper jaw reconstructions.