Dye Uptake Research Articles

Adsorption Behavior and Mechanism of Brilliant Green Dye onto Acid-modified Mesoporous Volcanic Pumice

Water pollution is a major problem in the environment. The important one is the dying effluent from the textile industry. Dye effluent has affected human health and aquatic life. Recently, natural adsorbents have been most commonly used for dye treatment wastewater. This study explores the adsorption mechanism of brilliant green onto HCl-modified pumice. It involves a comparative analysis of the raw and HCl-modified pumice's characterization and adsorption properties. The adsorption experiments were carried out by considering several parameters, such as pH, contact time, initial dye concentrations, and temperatures. The research indicated that the raw and acid-treated pumice possess Si-OH and Si-O-Si groups. These pumice adsorbents are classified as mesoporous, exhibiting BJH pore diameters of 3.23 nm for the raw form and 3.69 nm for the acid-modified variant. The adsorption data revealed that the uptake of brilliant green dye was maximal at a pH of 8. The equilibrium results closely matched the Langmuir isotherm model. The maximum adsorption capacities were 37.13, 40.17, and 42.73 mg g-1 for the raw pumice, and 46.72, 51.81, and 56.17 mg g-1 for the modified pumice at 20, 30, and 40 °C, respectively. Furthermore, the removal efficiency of brilliant green dye with modified pumice was 91.93%, 95.29%, and 96.27% at 20°C, 30°C, and 40°C, respectively. The pseudo-second-order model was the most suitable for elucidating the kinetic adsorption data. The thermodynamic analysis revealed that the adsorption process was endothermic, spontaneous, and physical. Dipole-dipole H-bonding interaction, Yoshida H-bonding, electrostatic interaction, n-𝝅 interaction, cation exchange, and pore filling were all engaged in its process. Consequently, the local pumice volcanic rock became a great, cheap, abundant, and environmentally friendly adsorbent for removing dyes from effluents.

Biocompatible Glycopolymer-PLA Amphiphilic Hybrid Block Copolymers with Unique Self-Assembly, Uptake, and Degradation Properties.

The self-assembly of Janus-type amphiphilic hybrid block copolymers composed of hydrophilic/hydrophobic layers has shown promise for drug encapsulation and delivery. Saccharides have previously been incorporated to improve the biocompatibility of self-assembled structures; however, glycopolymer block copolymers have been less explored, and their structure-property relationships are not well understood. In this study, novel glycopolymer-branched poly(lactic acid) (PLA) block copolymers were synthesized via thiol-ene coupling and their composition-dependent morphologies were elucidated. Stability as a function of pH, dye uptake capabilities, and cytotoxicity were evaluated. Systems with a hydrophilic weight ratio of 30% were found to produce bilayer nanoparticles, while systems with a hydrophilic weight ratio of 60% form micelles upon self-assembly in aqueous media. Regardless of composition and morphology, all systems exhibited uptake of both hydrophobic (curcumin, DL % from 4.25 to 11.55) and hydrophilic (methyl orange, DL % from 4.08 to 5.88) dye molecules with release profiles dependent on composition. Furthermore, all of the nanoparticles exhibited low cytotoxicity, confirming their potential for biomedical applications.

Ordered Mesoporous Carbon as Adsorbent for the Removal of a Triphenylmethane Dye from Its Aqueous Solutions.

A nanostructured material, ordered mesoporous carbon (OMC), was synthesised in metal- and halide-free form and its use for the sequestration of crystal violet, a hazardous triphenylmethane dye, is reported for the first time. The OMC material is characterised using scanning transmission electron microscopy with energy-dispersive spectroscopy for chemical analysis, by Fourier-transform infrared spectroscopy, and by nitrogen gas physisorption. The ideal conditions for the uptake of crystal violet dye were determined in batch experiments covering the standard parameters: pH, concentration, contact time, and adsorbent dosage. Experimental data are validated by applying Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The thermodynamic parameters, ΔH°, ΔG°, and ΔS°, are calculated and it has been found that the adsorption process is spontaneous and endothermic with increasing disorder. An in-depth analysis of the kinetics of the adsorption process, order of the reaction and corresponding values of the rate constants was performed. The adsorption of crystal violet over OMC has been found to follow pseudo-second-order kinetics through a film diffusion process at all temperatures studied. Continuous flow column operations were performed using fixed bed adsorption. Parameters including percentage saturation of the OMC bed are evaluated. The exhausted column was regenerated through a desorption process and column efficiency was determined.

Hybrid nanocellulose material as an adsorbent to remove reactive yellow 2 dye

Textile dyes are frequently disposable in aqueous effluents, making it difficult to remove them from industrial effluents before their release to natural waters. This paper deals with the fabrication of cellulose-based adsorbents by reacting nanocelulose crystalline (nanocel) with N-[3-(trimethoxysilyl)propyl]ethylenediamine (TMSPEDA), forming the hybrid (silylpropyl)ethylenediamine@nanocellulose (SPEDA@nanocel), which was employed as adsorbent for the uptake of reactive yellow 2 dye (RY-2) from aqueous effluents. Characterisation of SPEDA@nanocel was carried out using FTIR, SEM–EDS, XRD, TGA, surface area, pHpzc, and hydrophobicity/hydrophilicity ratio (HI). Also, adsorption studies were thoroughly investigated. The effect of initial pH indicated that the maximum uptake of RY-2 takes place at pH 2, which is an indication of the electrostatic mechanism. The kinetic data carried out with 250 and 500 mg L−1 RY-2 with SPEDA@nanocel followed better the nonlinear fractional-like pseudo-first-order model. The t0.5 and t0.95 for the dye uptake were about 30 and 141 min, respectively. The equilibrium data from 10 to 45 °C indicated that the Liu isotherm model was the best-fitted isothermal model. The maximum sorption capacity attained was 112.3 mg g−1 at 45 °C. The thermodynamic data have shown that the equilibrium was favorable and endothermic, and the ΔH° was compatible with an electrostatic attraction between RY-2 and SPEDA@nanocel. Experiments of desorption of loaded adsorbent showed promising results for real applications since at least 5 adsorption/desorption cycles could be employed without significant changes in the recovery and with high precision.

The role of carboxyl and cationic groups in low-level cationised cellulose fibres investigated by zeta potential and sorption studies

The anionic nature of both cellulose fibres and reactive dyes prevents substantial exhaustion of dye from the dyebath, which is at neutral pH before alkali is added to initiate dye fixation. Conventionally, salt is added to minimize the electrostatic repulsions that interfere with dye sorption, but that increases salt loads in effluents. An alternative is to affix cationic agents on the cellulose to overcome the inherent anionic charge, but that has generally been observed to result in uneven dye sorption. The focus of investigations in this work is to examine the influence of the ratio of charges on cellulose (of affixed cationic charges to inherent anionic charges) on the extents and evenness of dye sorption. The cationisation agent 3-chloro-2-hydroxypropyl-N,N,N-trimethylammonium chloride (CHPTAC) was grafted on loose viscose fibres to yield 12 to 185 mmol kg−1 cationic group content on the fibre that exhibited an inherent carboxyl group content of 68 mmol kg−1. Three different dyes (of varying molecular sizes and anionic group content) were employed for examination of sorption profiles. The results from both zeta potential measurements and dye sorption profiles showed evidence of limited dye uptake until the cationic group content in fibres exceeded that of the inherent carboxyl groups. Thereafter, an uptick in dye sorption was observed, with dye sorption levels increasing with rise in degree of cationisation. There were differences between the dyes in their degrees of sorption, which appear correlated with their molecular sizes.

Dyeing of polyacrylonitrile knitted fabric using liposomes

In this study, it was aimed to analyze the effects of liposomes on the dyeing of polyacrylonitrile fabrics. For this purpose, firstly liposome synthesis was carried out, and then liposome production was confirmed by Fourier transform infrared spectroscopy analysis. Additionally, zeta potential measurements were carried out to see whether stable structures were formed. Then, a selected basic dye was encapsulated with a liposome and the possibilities of using these capsules as alternative to retarders in the dyeing of polyacrylonitrile fabrics were examined. According to results obtained, it can be said that the 1% solution of synthesized liposomes creates a more stable suspension with a polydispersity index of 0.472 and the average particle size of 165.2 nm. On the other hand, it has been revealed that if 1% liposome is used in dyeing, a kind of retarder effect can be achieved in the dyeing of polyacrylonitrile fabrics. Moreover, it can be said that the decrease in color efficiency, that is, the loss of yield, caused by the use of liposome at the end of dyeing is lower compared to the retarder. This is also a very important issue, because a good retarder is expected to slow down the dye uptake, but not reduce the dye intake too much at the end of the dyeing. Dyeing levelness (%) was found to be 96.1, 97.4, and 97.1 for dyeings without auxiliary, with 1% cationic retarder and with 1% liposome, respectively. Beyond this, no significant difference was observed in terms of fastness of dyeing.

Investigating properties of sweet cherry (Prunus avium) flower buds that help promote freezing avoidance by supercooling.

Mechanisms involved in the supercooling of plant tissues as a means of low temperature survival are still not fully understood. We investigated properties that may promote supercooling in overwintering sweet cherry (Prunus avium) flower buds. We conducted experiments on sweet cherry flower buds using differential thermal analysis (DTA) and observed locations of ice formation in the bud structure. We also used anatomical development and water-soluble dye uptake throughout the overwintering period to identify changes that correlate with gain and loss of supercooling capacity. Our results revealed barriers to ice propagation are likely unique to each primordium, as inferred from exotherms produced from buds subjected to DTA, although multiple primordia may freeze simultaneously. Ice is accommodated between the bud scales and within the bud axis; however, full expression of supercooling was not dependent on the presence of scales. Anatomical and DTA studies revealed a correlation between vascular differentiation in primordia and loss of supercooling in the spring; these observations were at a higher temporal resolution than previously described for Prunus. Furthermore, disturbing tissues subtending the primordia interfered with typical patterns of supercooling, indicated more erratic and numerous exotherms produced during DTA. In summary, sweet cherry flower buds undergo extra-organ freezing. In winter, a barrier to ice propagation in the region directly subtending primordia protects the flower from freezing damage, but in the spring xylem differentiation in primordia provides a conduit for ice propagation that compromises supercooling.

Adsorptive removal of cationic dyes from wastewater using a novel sodium alginate-based iron oxide nanocomposite hydrogel: DFT and advanced statistical physics modelling

A novel Sodium alginate-based hydrogel reinforced with varying Fe2O3 nanoparticles loading (NCH) was synthesized to remove cationic dyes methylene blue (MB) and crystal violet (CV). The NCH, with 5 % Fe2O3 loading, demonstrated optimal removal efficiency for both dyes. Detailed spectroscopic, microscopic, and spectrometric characterization techniques verified the nanocomposite structure and dye adsorption. Batch experiments revealed that at pH: 9, with a 20 mg 100 mL−1 adsorbent dose and times of 60 min for MB and 40 min for CV, with an initial concentration of 500 mg L−1, maximum adsorption capacities were achieved. MB and CV adsorption onto NCH showed distinct mechanisms: MB via physical interaction, CV via both physical and chemical interactions, including electrostatic forces and hydrogen bonding. Despite differences, the Langmuir-Freundlich model best fit the equilibrium isotherms, suggesting monolayer adsorption dominated, even with heterogeneous surface sites on NCH. A dual-site M2 statistical physics model revealed that MB and CV adsorption occurred via a multi-molecular vertical configuration on the binding sites, with heterogeneous adsorption sites contributing to dye uptake. Density functional theory demonstrated higher adsorption affinity for MB over CV, primarily due to hydrogen bonding and electrostatic interactions. NCH exhibited 80 % dye removal efficiency after five cycles, highlighting its potential for industrial effluent treatment.

Gastric preconditioning via percutaneous angioembolization before esophagectomy in patients at high risk for esophageal leak.

Anastomotic leaks and stenoses remain critical complications in esophagectomy and are related to conduit perfusion. Surgical gastric preconditioning has been described but requires additional surgery and creates scar tissue, potentially hindering future operation. We sought to evaluate the feasibility and safety of percutaneous gastric preconditioning by angioembolization to improve perfusion of gastric conduits before esophagectomy in a high-risk patient cohort. Patients pending an esophagectomy for cancer and deemed to be high risk for anastomotic complications underwent preconditioning by image-guided angioembolization. Preconditioning was performed on an outpatient basis by means of superselective embolization of the left gastric and short gastric arteries. Intraoperative conduit perfusion evaluation with indocyanine green and postoperative surgical outcomes was reviewed. Seventeen patients underwent gastric preconditioning, with no complications observed. Thirteen of the 17 patients ultimately underwent esophagectomy; the remaining four patients were not candidates for an operation. Patients proceeded to surgery a median of 23days (interquartile range, 21-27days) after preconditioning. The intraoperative indocyanine green perfusion of all conduits was appropriate, with no tip demarcation and with a median time to dye uptake of 20s (interquartile range, 15-20s). There were no anastomotic stenoses or leaks noted within the series. Gastric conduit preconditioning by percutaneous angioembolization of the left gastric and short gastric arteries can be performed safely and without operative delay in high-risk patients. Further evaluation of preconditioning for conduit optimization is warranted to limit the critical complications of anastomotic leak and stenosis in esophagectomy.

Development of graphene oxide‐incorporated biopolymer‐carboxymethyl tamarind kernel gum‐based hydrogel as an effective adsorbent for the sequestration of dye pollutants

AbstractThe present study describes the facile synthesis of graphene oxide (GO) and GO/carboxymethyl tamarind kernel gum (CMTKG)‐based hydrogel composite. The synthesized GO/CMTKG/PAM hydrogel composite was applied as an adsorbent for the selective sequestration of toxic crystal violet (CV) and methylene blue (MB) from an aqueous medium. The impact of various controlling parameters such as contact time, pH, concentration, adsorbent dosage, and temperature was studied. The experimental data obtained from the isotherm and kinetics modeling showed a good correlation with the Langmuir isotherm and pseudo‐second‐order kinetics model, respectively. The optimized concentration of dye was 40 mg L−1 for CV and 20 mg L−1 for MB, and the adsorption capacity (qmax) was calculated to be 111 mg g−1 for CV dye and 25 mg g−1 for MB dye. The synthesized adsorbent exhibits excellent recyclability for dye uptake after six consecutive cycles. Furthermore, the simultaneous adsorption of CV and MB from the binary system was carried out to ascertain the utility of the adsorbent in a wide range of adsorption systems. The adsorbent was also found to act as a proficient adsorbent in various water samples. These results demonstrated that synthesized hydrogel can be successfully applied as an adsorbent for the sequestration of dye effluents in real‐time applications.Highlights Hydrogel composite was successfully synthesized via a free radical mechanism. It is an efficient adsorbent for removing cationic dyes from aqueous solutions. It shows selectivity towards cationic dyes and works in a binary mixture of cationic dyes. It shows good removal efficacy in different water samples, including real wastewater samples. It also shows proficient removal efficacy after six consecutive regeneration cycles.

Preparation and potential of chitosan-based/Al2O3 green hydrogel composites for the removal of methyl red dye from simulated solution.

Different dyes are discharged into water streams, causing significant pollution to the entire ecosystem. The present work deals with the removal of acid red 2 dye (methyl red-as an anionic dye) by green sorbents based on chitosan derivatization. In this regard, two classes of chitosan derivatives-a total of six-were prepared by gamma irradiation at 30kGy. The first group (group A) constitutes a crosslinked chitosan/polyacrylamide/aluminum oxide with different feed ratios, while the second group, identified as group B, is composed of crosslinked carboxymethyl chitosan/polyacrylamide/aluminum oxide with different ratios. Glycerol was added to soften the resultant hydrogels. The products were characterized by different tools, including FTIR for confirming the chemical modification, TGA for investigating their thermal properties, and XRD for verifying their crystalline structure. The morphology of the prepared derivatives was studied through SEM, while their topography before and after dye adsorption was monitored via the AFM. The removal efficiencies of the prepared sorbents were verified at different operation conditions, such as pH, temperature, adsorbent dose, initial concentration of dye solutions, and contact time. The data revealed that the optimum conditions for maximum dye uptake were as follows: pH 4, contact time 120min, 0.1-g sorbent dose, and 50-ppm dye concentration. Additionally, the prepared sorbents demonstrated potent adsorption capacity and removal efficiency. It was found that the elements of the second group displayed higher performance than their counterparts. The data showed also that the adsorption process best fits with the Freundlich model and obeyed pseudo-first-order kinetic isotherm. In addition, the synthesized composites showed observable antibacterial potency toward E. coli as a Gram-negative bacterium and S. aureus as a Gram-positive bacterium.

Stereocilia fusion pathology in the cochlear outer hair cells at the nanoscale level.

The hair bundle of cochlear hair cells comprises specialized microvilli, the stereocilia, which fulfil the role of mechanotransduction. Genetic defects and environmental noise challenge the maintenance of hair bundle structure, critically contributing to age-related hearing loss. Stereocilia fusion is a major component of the hair bundle pathology in mature hair cells, but its role in hearing loss and its molecular basis are poorly understood. Here, we utilized super-resolution expansion microscopy to examine the molecular anatomy of outer hair cell stereocilia fusion in mouse models of age-related hearing loss, heightened endoplasmic reticulum stress and prolonged noise exposure. Prominent stereocilia fusion in our model of heightened endoplasmic reticulum stress, Manf (Mesencephalic astrocyte-derived neurotrophic factor)-inactivated mice in a background with Cadherin 23missense mutation, impaired mechanotransduction and calcium balance in stereocilia. This was indicated by reduced FM1-43 dye uptake through the mechanotransduction channels, reduced neuroplastin/PMCA2 expression and increased expression of the calcium buffer oncomodulin inside stereocilia. Sparse BAIAP2L2 and myosin 7a expression was retained in the fused stereocilia but mislocalized away from their functional sites at the tips. These hair bundle abnormalities preceded cell soma degeneration, suggesting a sequela from stereociliary molecular perturbations to cell death signalling. In the age-related hearing loss and noise-exposure models, stereocilia fusion was more restricted within the bundles, yet both models exhibited oncomodulin upregulation at the fusion sites, implying perturbed calcium homeostasis. We conclude that stereocilia fusion is linked with the failure to maintain cellular proteostasis and with disturbances in stereociliary calcium balance. KEY POINTS: Stereocilia fusion is a hair cell pathology causing hearing loss. Inactivation of Manf, a component of the endoplasmic reticulum proteostasis machinery, has a cell-intrinsic mode of action in triggering outer hair cell stereocilia fusion and the death of these cells. The genetic background with Cadherin 23missense mutation contributes to the high susceptibility of outer hair cells to stereocilia fusion, evidenced in Manf-inactivated mice and in the mouse models of early-onset hearing loss and noise exposure. Endoplasmic reticulum stress feeds to outer hair cell stereocilia bundle pathology and impairs the molecular anatomy of calcium regulation. The maintenance of the outer hair cell stereocilia bundle cohesion is challenged by intrinsic and extrinsic stressors, and understanding the underlying mechanisms will probably benefit the development of interventions to promote hearing health.

Investigating the optimum conditions for azo dye (methyl orange and methyl red) decolorization from aqueous solution using oyster mushroom (Pleurotus ostreatus): a mycoremediation approach

Since conventional dye removal techniques require a substantial amount of energy and chemicals, this study evaluated the utilization of Pleurotus ostreatus, a species of fungus, in an environmentally beneficial mycoremediation approach to decolorize two azo dyes, methyl orange (MO) and methyl red (MR), in a liquid medium. Pleurotus ostreatus was utilized under standard circumstances in the solutions containing 0.05% (w/v) MO and 0.05% (w/v) MR, without undergoing any genetic modifications. By analyzing the effects of time (6, 12, and 18 days), temperature (15 °C to 40 °C), pH (4 to 7), and inoculum volume (1 to 25 mL) on the decolorization rate of P. ostreatus, the ideal environment for the decolorization of MO and MR was determined. The highest rate of decolorization was evident at 25 °C temperature, pH 7 within 18 days of incubation, P. ostreatus could decolorize 0.05 g MO up to 97% when added in 10 mL inoculum volume on the other hand 0.05 g MR up to 93% in 15 mL inoculum volume at pH 6. Furthermore, the dye uptake rate after 18 days for MO was 59.25% and MR was 53.97% which indicated that P. ostreatus had a better uptake efficiency for MO than MR. Based on its ability to decolorize both MO and MR under suitable circumstances, the study concludes that P. ostreatus offers an appreciable mycoremediation approach for removing dye pigments from industrial wastewater.

Analyzing the dyeing behaviour of easy dyeable and regular polyester by the influence of different heat-setting temperature

The heat-setting effects of easy-dyeable polyester (EDP) have been investigated by comparing it with regular polyester fabric (PES). Using XRD analysis, the crystallinity and amorphousness of the easy-dyeable polyester and regular polyester fabric were assessed after 45 s during heat-setting of EDP and PES at nominal temperatures (120, 140, 160, 180, and 200 °C). The heat-set of EDP and PES fabric were dyed separately and competitively at temperatures ranging from 100 to 130 °C using S-type (C.I. Disperse Red 167) and E-type (C.I. Disperse Red 60) dyes. The color strength (fk ) and dye uptake were found to be lower at the heat-setting temperatures of 180 °C for PES and 140 °C for EDP. To ascertain the impact of varying heat-setting temperatures on PES and EDP-dyed fabric, the dimensional stability and GSM were assessed. When the heat set temperature was raised from 140 °C, the EDP fabric showed greater dimensional stability. On the other hand, the dimensional stability of untreated PES fabric (−4.2% lengthwise) and GSM (111 g/m2) gradually stabilized when the heat-setting temperature increased. However, the color fastness rating has improved after applying the heat-setting process for PES and EDP at 180o C and 140 °C, respectively.

Revolutionizing dye removal from wastewater using low-cost natural material

The contamination of wastewater by textile dyes has emerged as a significant and pressing environmental concern that requires immediate attention and the development of inventive solutions. One highly effective technique for addressing this issue involves using adsorption processes with nanoparticles for dye removal. To address this challenge, white stone powder (WSP) and calcined white stone powder (CWSP) were prepared for their potential in adsorbing and removing dyes from wastewater. The effect of pH, dosage, contact time, initial dye concentrations, and temperature were optimized during the present study. Furthermore, the equilibrium data for the WSP was subjected to rigorous analysis using multiple isothermal models, including the Freundlich, Langmuir, Dubinin Radushkevich, Harkin Jura, and Temkin models. A comparison of calculated and experimental uptake capacities and higher values of the correlation coefficient indicated that the Freundlich model fited better than the other models. In addition to the isothermal modeling, the morphology of the adsorbent materials was examined. The dye uptake capacity (mg/g) of white stone powder was 72.24 which increased up to 92.56 after calcination. This research work highlighted the potential of the calcined WSP as a cost-effective and efficient alternative for removing dyes from wastewater, presenting a promising solution to this pressing environmental issue.

Renewing Interest in Zeolites as Adsorbents for Capture of Cationic Dyes from Aqueous and Ethanolic Solutions: A Simulation-Based Insight into the Efficiency of Dye Adsorption in View of Wastewater Treatment and Valorization of Post-Sorption Materials.

The impact of solvents on the efficiency of cationic dye adsorption from a solution onto protonated Faujasite-type zeolite (FAU-Y) was investigated in the prospect of supporting potential applications in wastewater treatment or in the preparation of building blocks for optical devices. The adsorption isotherms were experimentally determined for methylene blue (MB) and auramine O (AO) from single-component solutions in water and in ethanol. The limiting dye uptake (saturation capacity) was evaluated for each adsorption system, and it decreased in the order of MB-water > AO-water > AO-ethanol > MB-ethanol. The mutual distances and orientations of the adsorbed dye species, and their interactions with the oxygen sites of the FAU-Y framework, with the solvent molecules, and among themselves were inferred from Monte Carlo simulations and subsequently utilized to rationalize the observed differences in the saturation capacity. The dye-solvent competition and the propensity of the dyes to form compact pi-stacked dimers were shown to play an important role in establishing a non-uniform distribution of the adsorbed species throughout the porous space. The two effects appeared particularly strong in the case of the MB-water system. The necessity of including solvent effects in modeling studies is emphasized.

Purification of textile waste by extracting harmful contaminants using a bio-porous sorbent derived from Moroccan Pistacia lentiscus

The increasing problem of water contamination worldwide highlights the critical need to introduce environmentally-friendly treatment approaches. This study focuses on the use of powdered Pistacia lentiscus leaves as a highly effective adsorbent for removing crystal violet dye from textile waste. The bio-adsorbent were examined using SEM/EDX, FT-IR techniques.The process optimization showed that 98.25 % of cristal violet could be eliminated in 60 min at a pH 7.1 using 30 mg of 80 µm biosorbent. Analysis of kinetic and isothermal data for dye removal by L@PL powders revealed a better fit with the pseudo-second-order (PSO) kinetic model and the Freundlich isotherm model, respectively. The Freundlich isotherm model exhibited a strong fit, highlighting a maximum monolayer adsorption capacity of 93.03 mg g−1 at 25 °C. Thermodynamic studies revealed that dye uptake was mainly affected by physisorption and exhibited characteristics of spontaneity and endothermic behavior. Electrostatic interactions, π-π interactions and hydrogen bonds are among the mechanisms responsible for dye adsorption on biomass leaves. The use of naturals resources as bio-adsorbent, recognized for their abundance and cost-effectiveness, and environmentally friendly material for removing cationic dyes in the current study.

Exploring the Use of Natural Ingredients for the Protection of Textured Hair from Ultraviolet Radiation: An In Vitro Study

Human hair is characterized by significant diversity, which is dictated by the individual genetic makeup. It is estimated that up to 70% of the world’s population has textured hair, with a significant proportion also living in areas with high exposure to ultraviolet radiation (UVR). This highlights the unique requirements for textured hair care products that can protect hair shafts from the harmful effects of the environment whilst enhancing the natural features of the fibre. In this study, we investigated the UV-protective effects of hair conditioner formulated from active ingredients, mangiferin, ferulic acid and naringin. The analysis of UV-irradiated straight and textured hair was performed by measurements of hair thickness and darkness, the uptake of the fluorescent dye, spectral absorbance of keratin extracts, ATR-FTIR and SEM. We found that textured hair was more sensitive to UVR-induced changes than straight hair, with the primary molecular targets represented by chemical groups in keratins. Pre-treatment of the hair with conditioner had protective effects against structural damage and oxidative stress caused by UVR. These data indicate the importance of the personalized approach to hair research and the formulation of hair care products tailored to the individual demands of textured hair types.

Inhibition of astroglial hemichannels prevents synaptic transmission decline during spreading depression

BackgroundSpreading depression (SD) is an intriguing phenomenon characterized by massive slow brain depolarizations that affect neurons and glial cells. This phenomenon is repetitive and produces a metabolic overload that increases secondary damage. However, the mechanisms associated with the initiation and propagation of SD are unknown. Multiple lines of evidence indicate that persistent and uncontrolled opening of hemichannels could participate in the pathogenesis and progression of several neurological disorders including acute brain injuries. Here, we explored the contribution of astroglial hemichannels composed of connexin-43 (Cx43) or pannexin-1 (Panx1) to SD evoked by high-K+ stimulation in brain slices.ResultsFocal high-K+ stimulation rapidly evoked a wave of SD linked to increased activity of the Cx43 and Panx1 hemichannels in the brain cortex, as measured by light transmittance and dye uptake analysis, respectively. The activation of these channels occurs mainly in astrocytes but also in neurons. More importantly, the inhibition of both the Cx43 and Panx1 hemichannels completely prevented high K+-induced SD in the brain cortex. Electrophysiological recordings also revealed that Cx43 and Panx1 hemichannels critically contribute to the SD-induced decrease in synaptic transmission in the brain cortex and hippocampus.ConclusionsTargeting Cx43 and Panx1 hemichannels could serve as a new therapeutic strategy to prevent the initiation and propagation of SD in several acute brain injuries.

Organoclay-assisted disperse dyeing of polypropylene nanocomposite fabrics in supercritical carbon dioxide

Dyeing using supercritical carbon dioxide (SC-CO2) is carried out on the polypropylene (PP) nanocomposite fabrics with model disperse dye compared with their regular fabric at various dyeing temperatures and pressures. The results are compared with those obtained in aqueous dyeing method. The PP nanocompsite fabrics dyed in SC-CO2 medium exhibited higher colour strength (K/S) values compared with their PP regular fabric. The PP nanocompsite fabrics and their regular fabric dyed in SC-CO2 medium have higher K/S values than those dyed in aqueous medium. The color coordinates of all PP fabrics dyed in SC-CO2 and aqueous medium were positive with respect to a* and b* coordinates depending on the disperse red dye uptake. The PP nanocomposite fabrics dyed in SC-CO2 and aqueous medium exhibited higher antibacterial properties than their regular fabrics. All PP fabrics dyed in SC-CO2 and aqueous medium present very good washing, perspiration and light fastness.