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Luffasponge (fibrous network obtained from mature dried Luffa cylindrica) was activated using particulate materials to increase its adsorption capacity for fluoride ions from aqueous solution. The activation of the Luffa cylindricawith hydroxyapatite (HA) on the surface presented the best efficiency in the removal of fluoride ions. The presence of hydroxides (OH-) as active groups in the Luffa cylindricastructure are responsible for adsorption. In this work, the results of bioadsorption tests of fluoride ions with Luffa cylindrica-HA in fixed-bed columns are presented. The depth of mass transfer zone increased from 5.5 to 11.0 cm, with bed volumes of 4.32 and 8.64 cm3, respectively. The results were treated with various fixed-bed models (Thomas, Yoon-Nelson, DoseResponse and Weibull distribution). The results obtained showed that breakthrough time increases as the bed height increases. The bed capacity was 2.4 mg/g, with the bed depth, influent flow rate and influent concentration of 5.5-11.0 cm, 1 mL/min, and 5 mg/L, respectively. The breakthrough curve matched the Thomas, Yoon-Nelson, Dose-Response, and Weibull, models. The Weibull distribution model was used to predict the breakthrough curve from the experimental results. The results were well fitted to this model and the adsorption capacity was calculated. The study of the operating parameters of the column on a laboratory scale can be used to simulate the potential performance of the adsorbent and extrapolate the results to a pilot scale or larger.

In this present study, the AISI 1025 steel was pack-borided in the temperature range of 1,123–1,273 K for different treatment times ranging from 2 to 8 h. A diffusion model was suggested to estimate the boron diffusion coefficients in the Fe2B layers. As a result, the boron activation energy for the AISI 1025 steel was estimated as 174.36 kJ/mol. This value of energy was compared with the literature data. To extend the validity of the present model, other additional boriding conditions were considered. The boride layers formed on the AISI 1025 steel were characterized by the following experimental techniques: scanning electron microscopy, X-ray diffraction analysis and the Daimler–Benz Rockwell-C indentation technique. Finally, the scratch and pin-on-disc tests for wear resistance were achieved using an LG Motion Ltd and a CSM tribometer, respectively, under dry sliding conditions.

In this work, American Iron and Steel Institute (AISI) O1 steel was pack borided in the temperature range of 1123–1273K for treatment times between 2 and 8hours. A kinetic model was proposed for estimating the boron diffusion coefficients through the Fe2B layers. As a result, the boron activation energy for the AISI O1 steel was estimated as 197·2kJ mol− 1. This value of energy was compared to the literature data. In addtion, to extend the validity of the present model, two additional boriding conditions were done. The Fe2B layers grown on AISI O1 steel were characterised by use of the following experimental techniques: scanning electron microscopy, X-ray diffraction analysis and Daimler-Benz Rockwell-C indentation technique. Finally, the scratch and pin on disc tests for wear resistance were respectively performed using an LG Motion Ltd and a CSM tribometer under dry sliding conditions.

The microstructure simulation of spinodal decomposition was carried out in the isothermally-aged Cu-Ni-Fe alloys using the phase field method. The numerical simulation was based on a solution of the Cahn-Hilliard partial differential equation by the finite difference method. The calculated results were compared to those determined by atom-probe field ion microscope analyses of the solution treated and aged alloys. Both the numerically simulated and experimental results showed a good agreement for the concentration profiles and microstructure evolution in the aged Cu-Ni-Fe alloys. The aging process caused the change of initial morphology, iregular and interconected, to an equiaxial shape of the decomposed Ni-rich phase aligned in the elasticallysoftest crystallographic direction <100> of Cu-rich matrix.

Background and purpose The carotid stent placement as a therapeutic option for carotid stenosis has been increasing among years; therefore, studies are required to evaluate the security and efficacy of its materials. The purpose of this study was to evaluate the distal filter and the proximal balloon-guided catheter with flow inversion as protection devices during carotid angioplasty and stenting.Methods This is a retrospective, observational study of patients diagnosed with carotid stenosis treated with angioplasty between January 1, 2014, and June 30, 2020; we analyzed a radiology service database to compare the distal filter and the proximal balloon-guided catheter as protection devices during angioplasty.Results One hundred seventy-five angioplasties were performed, the distal filter was the most prevalent embolic protection device used (66%), patients baseline characteristics did not differ between groups with different embolic protection devices, except for history of dyslipidemia (p<0.000). As well, we did not find any significant differences between the groups in the device related complications, intervention time (p=0.140),unrelated complications (p=0.693) andfunctional independence at 90 days (p = 0.096).Conclusions In our study the proximal balloon-guided catheter and the distal filter protection device as protection devices during the carotid stenting didn't show significant differences regarding complications related to the system.

Sparfloxacin is a new oral fluoroquinolone agent with putative activity against common pediatric pathogens. Using the broth microdilution method, we evaluated sparfloxacin activity in comparison with those of other antimicrobial agents against 383 pediatric isolates derived from cultures of blood and other normally sterile body fluids. MICs were assessed in Mueller-Hinton broth, serum, and urine, as well as at inoculum sizes of 10(4) to 10(8) CFU/ml. The emergence and stability of resistance and cross-resistance of Pseudomonas aeruginosa (mucoid and nonmucoid) and Staphylococcus aureus to sparfloxacin and ciprofloxacin were evaluated. Inhibitory activity of sparfloxacin against most test organisms was within achievable serum levels. Sparfloxacin was greater than or equal to 2- to 4-fold more active than other quinolones against gram-positive pathogens and 2- to 4-fold less active than ciprofloxacin against P. aeruginosa. Sparfloxacin activity was unaffected by urine and was enhanced by two- to eightfold in human serum. Its potency was not affected by inocula of less than or equal to 10(7) CFU/ml. The frequency of development of spontaneous resistance was similar to that found for other new quinolone agents, and stable resistance emerged only in P. aeruginosa. Sparfloxacin merits additional study against invasive pediatric pathogens.

Nucleotides and calcium ions have been implicated in the regulation of biosynthesis of steroids, although the exact locus of calcium activity is not yet known. The administration of Ca to Leydig cells increases testosterone production. Steroid sulfatase activity is reported to be enhanced by adenine nucleotides. In the present study the testicular sulfatase was evaluated in subcellular fractions by conversion of sulfate to free steroids in the presence or absence of Ca2+ and Mg2+ ions. The specific activity of the enzyme, which was located predominantly in submitochondrial fraction, showed a positive correlation with calcium, increasing 1.5-fold in the presence of 2.54 mM of calcium (62 nmol/ h mg protein-1). In contrast, magnesium inhibited the enzymatic activity 1.79-fold in presence of 1.18 mM (23 nmoles/h mg protein-1). It would appear that testicular sulfatase is predominantly located in the mitochondria, which is recognized as one of the major sites of control of intracellular metabolism, and that its enzymatic activity could be modulated by calcium regulating the levels of potentially active androgens.

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Summary. Composite materials polylactic acid/Reduced graphitic oxide (PLA/RGO) were prepared using the method of mixing chloroform solution. the chemical structure of chemically modified RGO obtained after reduction GO by infrared spectroscopy (FT-IR) was studied. PLA composites with different contents of RGO (1-3 wt%) in terms of distribution and morphology were compared, using optical microscopy. RGO better dispersion in the matrix of the PLA using chloroform as a solvent and 3% by weight of RGO was obtained.