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Concept: Dye


Beta-arrestins regulate G protein-coupled receptor signaling as competitive inhibitors and protein adaptors. Low molecular weight biased ligands that bind receptors and discriminate between the G protein dependent arm and beta-arrestin, clathrin-associated arm of receptor signaling are considered therapeutically valuable as a result of this distinctive pharmacological behavior. Other than receptor agonists, compounds that activate beta-arrestins are not available. We show that within minutes of exposure to the cationic triphenylmethane dyes malachite green and brilliant green, tissue culture cells recruit beta-arrestins to clathrin scaffolds in a receptor-activation independent manner. In the presence of these compounds G protein signaling is inhibited, ERK and GSK3β signaling are preserved, and the recruitment of the beta2-adaptin, AP2 adaptor complex to clathrin as well as transferrin internalization are reduced. Moreover, malachite green binds beta-arrestin2-GFP coated immunotrap beads relative to GFP only coated beads. Triphenylmethane dyes are FDA approved for topical use on newborns as components of triple-dye preparations, and are not approved but used effectively as aqueous antibiotics in fish husbandry. As possible carcinogens their chronic ingestion in food preparations, particularly through farmed fish, is discouraged in the US and Europe. Our results indicate triphenylmethane dyes as a result of novel pharmacology may have additional roles as beta-arrestin/clathrin pathway signaling modulators in both pharmacology research and clinical therapy.

Concepts: Pharmacology, Signal transduction, Cell membrane, Receptor antagonist, Membrane biology, Dye, G protein, Triarylmethane dyes


MoS(2) nanosheet-coated TiO(2) nanobelt heterostructures-referred to as TiO(2) @MoS(2) -with a 3D hierarchical configuration are prepared via a hydrothermal reaction. The TiO(2) nanobelts used as a synthetic template inhibit the growth of MoS(2) crystals along the c-axis, resulting in a few-layer MoS(2) nanosheet coating on the TiO(2) nanobelts. The as-prepared TiO(2) @MoS(2) heterostructure shows a high photocatalytic hydrogen production even without the Pt co-catalyst. Importantly, the TiO(2) @MoS(2) heterostructure with 50 wt% of MoS(2) exhibits the highest hydrogen production rate of 1.6 mmol h(-1) g(-1) . Moreover, such a heterostructure possesses a strong adsorption ability towards organic dyes and shows high performance in photocatalytic degradation of the dye molecules.

Concepts: Chemical reaction, Hydrogen, Catalysis, Atom, Chemical bond, Dye, Heterojunction, Hydrogen production


A biosorbent was developed by simple dried Agaricus bisporus (SDAB) and effectively used for the biosorption of cationic dyes, Crystal Violet and Brilliant Green.

Concepts: Dye, Dyes, Pigment, Mushroom, Triarylmethane dyes, Agaricus bisporus, Phthalocyanine


Purified laccase from Trametes polyzona WR710-1 was used as biocatalyst for bisphenol A biodegradation and decolorization of synthetic dyes. Degradation of bisphenol A by laccase with or without redox mediator, 1-hydroxybenzotriazole (HBT) was studied. The quantitative analysis by HPLC showed that bisphenol A rapidly oxidized by laccase with HBT. Bisphenol A was completely removed within 3 h and 4-isopropenylphenol was found as the oxidative degradation product from bisphenol A when identified by GC-MS. All synthetic dyes used in this experiment, Bromophenol Blue, Remazol Brilliant Blue R, Methyl Orange, Relative Black 5, Congo Red, and Acridine Orange were decolorized by Trametes laccase and the percentage of decolorization increased when 2 mM HBT was added in the reaction mixture. This is the first report showing that laccase from T. polyzona is an affective enzyme having high potential for environmental detoxification, bisphenol A degradation and synthetic dye decolorization.

Concepts: Enzyme, Redox, Nicotinamide adenine dinucleotide, Dye, Triarylmethane dyes, Azo dyes, Acridine, Phthalocyanine


Reactive black B (RBB) is a group of azo dyes that are widely used in the textile industry. In this study, a new microbial strain was isolated from azo dye contaminated river sediment which is capable of degrading RBB. The strain was identified as Bacillus cereus strain HJ-1 by 16S rRNA gene sequences analysis. The optimal conditions for RBB decolorization by B. cereus strain HJ-1 are: 25°C, pH 8, 1 CMC of triton X-100, 0.15gL(-1) of added yeast extract, 0.125gL(-1) of added glucose and static culture. Then the toxicity of RBB on the green algae Chlorella vulgaris was determined. The results showed that the median effective concentration (EC(50)) of RBB for C. vulgaris is 48mgL(-1) and toxicity will really decrease after decolorization. In the end, B. cereus strain HJ-1 was amended into the origin river sediment and analyzed the whole microbial community structure of river sediment samples by PCR-DGGE technique. The result showed that B. cereus strain HJ-1 could survive in the river sediment after 12d of incubation. Based on this work, we hope that these findings could provide some useful information for applying the decolorization of RBB in our environment.

Concepts: Microbiology, Ribosomal RNA, 16S ribosomal RNA, Dye, Azo compound, Pigments, Azo dyes, Chlorella


Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA) in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v), respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL(50) equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes.

Concepts: Serum albumin, Dye, Bovine serum albumin, Azo compound, Pigments, Azo dyes


Adsorption of seven different organic dyes from aqueous solutions onto magnetite nanoparticles loaded tea waste (MNLTW) was studied. MNLTW was prepared via a simple method and was fully characterized. The properties of this magnetic adsorbent were characterized by scanning electron microscopy and X-ray diffraction. Adsorption characteristics of the MNLTW adsorbent was examined using Janus green, methylene blue, thionine, crystal violet, Congo red, neutral red and reactive blue 19 as adsorbates. Dyes adsorption process was thoroughly studied from both kinetic and equilibrium points of view for all adsorbents. The experimental isotherm data were analyzed using Langmuir, Freundlich, Sips, Redlich-Peterson, Brouers-Sotolongo and Temkin isotherms. The results from Langmuir isotherm indicated that the capacity of MNLTW for the adsorption of cationic dyes was higher than that for anionic dyes. The adsorption kinetics was tested for the pseudo-first order and pseudo-second order kinetic models at different experimental conditions.

Concepts: Electron, Electron microscope, Chemistry, Adsorption, Dye, Scanning electron microscope, Freundlich equation, Kinetics


In this study, a waste biomass of Punica granatum L. (P. granatum L.) peels was firstly characterized by means of Brunauer-Emmett-Teller (BET) surface area, elemental analysis, FT-IR, thermogravimetric (TG) analysis and zeta potential measurement techniques. FT-IR results indicated that the mechanism involved in the biosorption of lead(II) ions and AB40 onto biosorbent was mainly attributed to lead(II) ions and dye binding of amino, carboxylic, hydroxyl and carbonyl groups. The biosorption abilities of P. granatum L. peels for lead(II) ions and Acid Blue 40 (AB40) were then investigated. Biosorption equilibrium and kinetic data fit well by the Langmuir isotherm and the pseudo-second-order kinetic models, respectively. The maximum biosorption capacities were 193.9 mg g(-1) for lead(II) ions and 138.1 mg g(-1) for AB40. Biosorption processes were spontaneous and endothermic in nature according to the thermodynamic results and the equilibrium was attained within 50 min. The validity of used kinetic models in this study can be quantitatively checked by using a normalized standard deviation Δq(%). Finally, the biosorption procedure was adopted to treat the real and simulated wastewaters including several metal salts and dyes. The wastewater applications have shown that the biosorbent indicated a reasonable biosorption capability to remove lead(II) ions (98.07%) and AB40 (94.76%) from industrial wastewaters.

Concepts: Acid, Ammonia, Temperature, Thermodynamics, Standard deviation, Dye, Standard score, Pomegranate


A minimally destructive technique for the determination of dyes in finished fibers provides an important tool for crime scene and other forensic investigations. The analytical power and the minimal sample consumption of time-of-flight-secondary ion mass spectrometric (TOF-SIMS) analysis provides the ability to obtain definitive molecular and elemental information relevant to fiber identification, including identification of dyes, from a very small volume of sample. For both fiber surface analysis and, with the aid of cryomicrotomy, fiber cross-section analysis, TOF-SIMS was used to identify various dyes in finished textile fibers. The analysis of C.I. Acid Blue 25 in nylon is presented as a representative example. The molecular ion of C.I. Acid Blue 25 with lower than 3% on weight-of-fiber (owf) dye loading cannot be identified on dyed nylon surfaces by TOF-SIMS using a Bi(3)(+) primary ion beam. Sputtering with C(60)(+) provided the ability to remove surface contamination as well as at least partially remove Bi-induced damage, resulting in a greatly improved signal-to-noise ratio for the Acid Blue 25 molecular ion. The use of C(60)(+) for damage removal in a cyclic manner along with Bi for data acquisition provided the ability to unambiguously identify Acid Blue 25 via its molecular ion at a concentration of 0.1% owf from both fiber surfaces and cross sections.

Concepts: Mass spectrometry, Molecule, Chemistry, Ion, Nylon, Fiber, Dye, Secondary ion mass spectrometry


Application of pigments in textile coloring has many advantages such as less water and energy consumption, less effluent load and higher efficiency, so the pigments are perfect alternatives to dyes for eco-friendly coloring. In this work, a stable anionic nanoscale pigment suspension was prepared using a polymeric dispersant to color the cationised cotton with the exhaust method. Meanwhile, ultrasound was carried out during the adsorption to evaluate the ultrasonic influences on the uptake of pigment, adsorption efficiency and final product quality. The uptake of pigment is found to be higher with ultrasonic method than that with conventional technique because of the good dispersing capacity of ultrasound to pigment particles. Besides, it is found that nanoscale pigment has higher adsorption rate when using ultrasonic method because the ultrasound promotes the diffusion of pigment through the fiber-liquid boundary layer. Lastly, the color difference (ΔE) reveals the nanoscale pigment can be deposited on cotton surface more uniformly under ultrasonic condition, improving the product quality obviously.

Concepts: Purple, Dye, Pigment, Pigments, Textile, Hue, Form of the Good, Biological pigment