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In this research, activated carbon (AC) was synthesized from ligno-cellulosic residues of Adansonia kilima (Baobab) wood chips (AKTW) using two-step semi-carbonization and subsequent pyrolysis using microwave-induced heating (MWP) in the presence of a mild activating agent of K2CO3. The influence of process input variables of microwave power (x1), residence time (y1), and amount of K2CO3 (z1) were analysed to yield superior quality carbon having maximum removal efficiencies (R1) for lead (II) cations from waste effluents, fixed carbon percentages (R2), and carbon yield percentages (R3). Analysis of variance (ANOVA) was used to develop relevant mathematical models, with an appropriate statistical assessment of errors. Level factorial response surface methodology (RSM) relying on the Box-Behnken design (BBD) was implemented for the experimental design. The surface area and porous texture of the samples were determined using Brunauer, Emmett, and Teller (BET) adsorption/desorption curves based on the N2 isotherm. Surface morphological structure was observed using field emission scanning electron microscopic (FESEM) analysis. Thermogravimetric analysis (TGA) was carried out to observe the thermal stability of the sample. Change in the carbon content of the samples was determined using ultimate analysis. X-ray diffraction (XRD) analysis was performed to observe the crystalline and amorphous texture of the samples. The retention of a higher proportion of fixed carbon (80.01%) ensures that the synthesized adsorbent (AKTWAC) will have a greater adsorption capacity while avoiding unwanted catalytic activity for our synthesized final sample.
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This study deals with the preparation of activated carbon (CDSP) from date seed powder (DSP) by chemical activation to eliminate polyaromatic hydrocarbon-PAHs (naphthalene-C10H8) from synthetic wastewater. The chemical activation process was carried out using a weak Lewis acid of zinc acetate dihydrate salt (Zn(CH3CO2)2·2H2O). The equilibrium isotherm and kinetics analysis was carried out using DSP and CDSP samples, and their performances were compared for the removal of a volatile organic compound-naphthalene (C10H8)-from synthetic aqueous effluents or wastewater. The equilibrium isotherm data was analyzed using the linear regression model of the Langmuir, Freundlich and Temkin equations. The R2 values for the Langmuir isotherm were 0.93 and 0.99 for naphthalene (C10H8) adsorption using DSP and CDSP, respectively. CDSP showed a higher equilibrium sorption capacity (qe) of 379.64 µg/g. DSP had an equilibrium sorption capacity of 369.06 µg/g for C10H8. The rate of reaction was estimated for C10H8 adsorption using a pseudo-first order, pseudo-second order and Elovich kinetic equation. The reaction mechanism for both the sorbents (CDSP and DSP) was studied using the intraparticle diffusion model. The equilibrium data was well-fitted with the pseudo-second order kinetics model showing the chemisorption nature of the equilibrium system. CDSP showed a higher sorption performance than DSP due to its higher BET surface area and carbon content. Physiochemical characterizations of the DSP and CDSP samples were carried out using the BET surface area analysis, Fourier-scanning microscopic analysis (FSEM), energy-dispersive X-ray (EDX) analysis and Fourier-transform spectroscopic analysis (FTIR). A thermogravimetric and ultimate analysis was also carried out to determine the carbon content in both the sorbents (DSP and CDSP) here. This study confirms the potential of DSP and CDSP to remove C10H8 from lab-scale synthetic wastewater.
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Ácidos de Lewis/química , Modelos Moleculares , Naftalenos/análisis , Temperatura , Compuestos Orgánicos Volátiles/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Difusión , Cinética , Modelos Lineales , Nitrógeno/química , Espectrometría por Rayos X , Termogravimetría , Factores de TiempoRESUMEN
Introduction: This study, assess the efficacy of curcumin therapy in preventing/improving cochlear damage in Rattus norvegicus ototoxic model as evaluated with OAE examination. Materials and Methods: This study utilized 27 rats which had been injected with single dose 8mg/KgBB of cisplatin, and then divided into 3 groups. The first group was not given curcumin. The second group received curcumin at a dose of 150 mg/KgBB. The third group received curcumin at a dose of 300 mg/KgBB. Curcumin was given from the time of single dose cisplatin injection (day 0) to day 7. OAE examination was performed on the day before the single dose of cisplatin (day 0), day 3, 4 and 7 after curcumin administration. Results: There was a decline in the average value of SNR in all groups starting from high frequency. However, in the rat groups receiving curcumin there was a slow decrease in the SNR value, which also obtained statistically significant differences in the SNR values of all groups. Conclusion: Administration of certain doses of curcumin may reduce the modest and statistically insignificant decrease in mean SNR values indicating a reduction in ototoxicity from cisplatin.
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Aim To assess the cochlear damage caused by cisplatin in the rat cochlea based on decreased signal to noise ratio (SNR) values on otoacoustic emission (OAE) examination and increased expression of signal transducer and activator of transcription 1 (STAT 1) and vascular endothelial growth factor (VEGF) on immunohistochemical examination. Methods Twenty-four Rattus norvegicus were divided into 4 groups and injected with 8 mg/kgBW of cisplatin intraperitoneally except for control group. The SNR on OAE examination were checked before the treatment and on day 3, 4, and 7 after the treatment. The cochleas were stained immunohistochemically, followed by assessment of the cochlear organ of Corti damage based on STAT 1 and VEGF expression. Results A decrease in the mean of SNR value was found in accordance with the length of cisplatin exposure. The STAT 1 and VEGF expression increased with duration of cisplatin exposure. A correlation was found between SNR values, STAT 1, and also VEGF expression (p<0.05). Conclusion An increase of STAT 1 and VEGF expression influences cochlear damage due to cisplatin administration. There was a correlation between STAT 1 and VEGF expression with SNR values in the cochlear organ of Corti of Rattus norvegicus exposed to cisplatin.
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With the unique properties such as high surface area to volume ratio, stability, inertness, ease of functionalization, as well as novel optical, electrical, and magnetic behaviors, nanomaterials have a wide range of applications in various fields with the common types including nanotubes, dendrimers, quantum dots, and fullerenes. With the aim of providing useful insights to help future development of efficient and commercially viable technology for large-scale production, this review focused on the science and applications of inorganic and organic nanomaterials, emphasizing on their synthesis, processing, characterization, and applications on different fields. The applications of nanomaterials on imaging, cell and gene delivery, biosensor, cancer treatment, therapy, and others were discussed in depth. Last but not least, the future prospects and challenges in nanoscience and nanotechnology were also explored.
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Nanoestructuras/química , Nanotecnología/métodos , Técnicas Biosensibles , Nanopartículas/químicaRESUMEN
Behaviors of cationic and nonionic mixed micelles in the form of hexadecyltrimethylammonium bromide (HDABr) and hexadecyltrimethylammonium bromide-Polyethylene glycol hexadecyl ether (C16E20), in the presence of inert salts (NaBr and 3,5-dichlorosodium benzoate), by the use of reaction probe between Pp and ionized PhSH (Pp = piperidine and PhSH = phenyl salicylate), has been reported in this work. The values of RXBr (RXBr denotes ion exchange constants obtained in the presence of micelles of different structural features) or KXBr (KXBr denotes ion exchange constants obtained in the presence of micelles of the same structural features) for 3,5-Cl2C6H3CO2- were almost the same at three different [HDABr]T (0.006, 0.010 and 0.015 M). The average value of RXBr or KXBr determined, in the presence of pure HDABr micelles, using semi empirical kinetic (SEK) method appeared to be almost 2½-fold larger (RXBr or KXBr = 198) than that in the presence of mixed HDABr-C16E20 micelles (RXBr or KXBr = 78). Rheological measurements indicated the existence of wormlike/twisted micelles and vesicle at 0.015 M pure HDABr, various [3,5-Cl2C6H3CO2Na], and 25 and 35â whereas there were evidence of only spherical micelles in the presence of mixed HDABr-C16E20 ([HDABr]T = 0.015 M and [C16E20]T = 0.006 M) at both temperatures.
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Bromuros/química , Clorobenzoatos/química , Micelas , Piperidinas/química , Salicilatos/química , Compuestos de Sodio/química , Catálisis , Cetomacrogol/química , Cinética , Compuestos de Amonio Cuaternario/química , ReologíaRESUMEN
This study was conducted to improve the life-span of the biofilm produced from algae by evaluating the decomposition rate with the effect of cinnamon extraction oil (CEO). The biofilm was fabricated using the solution casting technique. The soil burying analysis demonstrated low moisture absorption of the biofilm, thus decelerating the degradation due to low swelling rate and micro-organism activity, prolonging the shelf-life of the biofilm. Hence, the addition of CEO also affects the strength properties of the biofilm. The maximum tensile strength was achieved with the addition of 5% CEO, which indicated a good intermolecular interaction between the biopolymer (algae) and cinnamon molecules. The tensile strength, which was measured at 4.80 MPa, correlated with the morphological structure. The latter was performed using SEM, where the surface showed the absence of a separating phase between the biofilm and cinnamon blend. This was evidenced by FTIR analysis, which confirmed the occurrence of no chemical reaction between the biofilm and CEO during processing. The prolongation shelf-life rate of biofilm with good tensile properties are achievable with the addition of 5% of CEO.
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The efficiency of counterion affinity towards ionic micelles is often described in terms of the degree of counterion binding (ß X ) to ionic micelles or the conventional ion-exchange constant ([Formula: see text]) or relative binding constant ([Formula: see text]) of X - and Br- counterions. This review describes the use of ionized phenyl salicylate ions, PSa-, as a new probe to determine [Formula: see text] values using a semiempirical spectrophotometric method. The value of [Formula: see text] is found to be comparable to reported values obtained using different probes by the semiempirical kinetic method as well as different physical methods. Application of semiempirical methods for calculation of [Formula: see text] or [Formula: see text] values involves an inherent assumption that these values are independent of the physicochemical characteristics of the probe molecule.
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Sondas Moleculares/química , Salicilatos/química , Cationes/química , MicelasRESUMEN
This paper discusses the unprecedented microscopic findings of micellar growth in colloidal system (CS) of catalyzed piperidinolysis of ionized phenyl salicylate (PS-). The giant vesicles (GV) was observed under the optical polarization microscope (OPM) at [NaX]=0.1M where X=3-isopropC6H4O-. The conditions were rationalized from pseudo-first-order rate constant, kobs of PS- of micellar phase at 31.1×10-3s-1 reported in previous publication. The overall diameter of GV (57.6µm) in CS (CTABr/NaX/H2O)-catalyzed piperidinolysis (where X=3-isopropC6H4O) of ionized phenyl salicylate were found as giant unilamellar vesicles (GUV) and giant multilamellar vesicles (GMV). The findings were also validated by means of rheological analysis.
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The present study is focused on the effect of the TTABr/MX/H2O-nanoparticles on the rate of piperidinolysis of ionized phenyl salicylate where TTABr represents tetradecyltrimethylammonium bromide and MX = NaCl, NaBr and CnH2n+1CO2Na with n = 4, 5, 6 and 7. Pseudo-first-order rate constant for the piperidinolysis of ionized phenyl salicylate at 35°C and constant concentration [PSa(-)]T = 0.2 mM, [Pip]T = 0.1 M, [NaOH] = 30 mM, [TTABr]T and different [MX] follow an empirical relationship which gives two empirical constant, (X)kcat and K(X/S). The value of relative counterion (X) binding constant, RX(Br) were calculated from the relationship; RX(Br) = (X)kcat/(Br)kcat. The values of RX(Br) for X = C4H9CO2(-), C5H11CO2(-), C6H13CO2(-), and C7H15CO2(-) are increasing with increase in the number of alkyl chain of counterion X.