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1.
Int J Biol Macromol ; 182: 1953-1965, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062162

RESUMO

A durable and reversible acid-induced discoloration azobenzene UV-curable lignin-based waterborne polyurethane polymeric dye (EDA-ULPD) is prepared from lignin, azobenzene and pentaerythritol triacrylate(PETA) by chemical modification of waterborne polyurethane. Lignin and PETA are chemically bonded to the polyurethane chain to improve thermal stability, UV resistance and color fastness, while also endow the polymeric dye with UV curing performance, which is a green and environmentally friendly fixing way. The acid-induced discoloration property of EDA-ULPD with azobenzene chromophore side chain is comparable to those of 4-ethyl-4-2,2'-dihydroxy diethylamine azobenzene (EDA). As the pH value decreases from 7 to 1, the maximum absorption peak of EDA-ULPD from 420 nm to 530 nm, and the color change from yellow to pink due to the transformation of EDA molecular structure from diazo to hydrazone. Interestingly, when EDA-ULPD is fixed to the fabric in the way of UV curing, its printed fabric exhibits the performance of high concentration acid-induced discoloration (1 mol·L-1 HCl) due to the cross-linked structure formed by EDA-ULPD. The acid-induced discoloration property of EDA-ULPD printed fabrics also presents outstanding repetitious stability. The stimulus response printed fabric with reversible high concentration acid discoloration possesses a broad application prospect in smart textiles.


Assuntos
Ácidos/química , Compostos Azo/química , Corantes/química , Lignina/química , Polímeros/química , Poliuretanos/química , Raios Ultravioleta , Água/química , Compostos Azo/síntese química , Varredura Diferencial de Calorimetria , Cor , Corantes/síntese química , Reagentes para Ligações Cruzadas/química , Peso Molecular , Polímeros/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Espectrofotometria Infravermelho , Temperatura
2.
Food Chem ; 360: 129977, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34023712

RESUMO

Organic acids, as an important component of food, have great influence on the flavor, texture, freshness of food. By lowering the pH of food to bacteriostatic acidity, organic acids are also used as additives and preservatives. Because organic acids are crucial to predict and evaluate food maturity, production and quality control, the rapid and sensitive determination methods of organic acids are necessary. This review aims to summarize and update the progress of the determination of organic acids in food samples. Pretreatment methods include simple steps (e.g., "dilute and shoot," protein precipitation, filtration, and centrifugation) and advanced microextraction methods (e.g., hollow fiber liquid phase microextraction, stir bar sorptive extraction and dispersive micro-solid phase extraction). Advances in novel materials (nanomaterial), solvents (ionic liquids and supercritical fluids) and hybrid methods are clearly displayed in detail. Continuous progress which has been made in electrochemical method, two-dimensional chromatography, high resolution mass is thoroughly illustrated.


Assuntos
Ácidos/análise , Análise de Alimentos/métodos , Ácidos/química , Ácidos/isolamento & purificação , Solventes/química
3.
Food Chem ; 359: 129935, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33934032

RESUMO

To understand the specific contributions of amorphous sugars and organic acids to the quality of food matrix, the solid model system of jujube slice skeleton (JSS) was firstly established. Effects of fructose (F), glucose (G), malic acid (M) and citric acid (C) on the glass transition temperature (Tg) and crystallization of JSS were studied. JSS-F/G/M/C blends were prepared by osmosis in the solution at a range of 0 ~ 32 g/100 g. Sugars reduced the Tg in the system, structure of JSS-G/M blends was changed from "amorphous glassy" to "amorphous rubbery" by increasing the osmotic solute concentration. Tg was decreased from 50.8 to 14.0 °C when JSS was osmosed in a 4 g/100 g fructose solution. Organic acids induced their crystallization in JSS. The crystallinity of JSS-M immersed in 32 g/100 g osmotic solution concentration was increased from 2% to 75%. Fructose presented greater influence on the adverse quality of jujube slices.


Assuntos
Ácidos/química , Compostos Orgânicos/química , Açúcares/química , Temperatura de Transição , Vitrificação , Ziziphus/química , Varredura Diferencial de Calorimetria , Cristalização , Vidro/química , Temperatura , Água/química
4.
J Food Sci ; 86(6): 2481-2490, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33948960

RESUMO

The migration study of nano-Ag migration from polylactic acid (PLA) films was studied. Samples treated by high-pressure food processing (0, 100, 200, 300, and 400 MPa pressure) were soaked in acetic acid solution and incubated at 20 °C for 90 days. At the end of storage, nano-Ag particles (AgNPs) migration from the PLA/AgNPs composite film treated under 200 MPa high pressure was the lowest. However, AgNPs migration was accelerated under 400 MPa high pressure. High-pressure processing (200 MPa) could cause denser structure and higher crystallinity degree in films than other treatments. Lower amount of AgNPs induced a decline in the intensity of specific characteristic peaks. The diffraction peak intensity of α-crystal for the film sample treated with 400 MPa was the lowest on day 60. The crystallization index of the PLA matrix changed with different high-pressure processing. The result indicated that appropriate high-pressure food processing could effectively suppress AgNPs migration from PLA-based film while contacting with acidic acid food simulant. PRACTICAL APPLICATION: The release of nanoparticles from food packaging material is a very important matter when the migration is concerned with regulatory and toxicity issues. The study described the migration kinetic of AgNPs from PLA nanocomposite film into acidic food simulant after different high-pressure food processing. The results indicated that the PLA/AgNPs nanocomposite film was safe for acidic food after high-pressure treatment.


Assuntos
Ácidos/análise , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Nanocompostos/química , Poliésteres/química , Pressão , Prata/fisiologia , Ácidos/química , Cinética , Prata/química
5.
Food Chem ; 360: 130001, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34000631

RESUMO

Food processing might induce the transformation of hidden ZEN (zein-bound ZEN) in maize. The objective of this study was to assess the effect of processing factors on free ZEN and hidden ZEN. After zein was treated under different temperature and pH, ZEN was quantified in samples before and after in vitro digestion. The ratios of hidden to total ZEN in zein are decreased from 54.25% to 40.74% after thermal treatment and from 54.25% to 0 after alkaline treatment, respectively. Conversely, acid treatment increased the ratio of hidden to total ZEN from 54.25% to 100%. Thus, it can be concluded that thermal or alkaline condition induced the conversion of hidden ZEN to free ZEN while acid condition promoted the ZEN-zein interactions to form the hidden ZEN. Overall, temperature and pH values played a vital role in the conversion of hidden ZEN during food processing.


Assuntos
Zearalenona/análise , Zeína/química , Ácidos/química , Álcalis/química , Cromatografia Líquida de Alta Pressão , Digestão , Manipulação de Alimentos , Concentração de Íons de Hidrogênio , Estabilidade Proteica , Espectrometria de Massas em Tandem , Temperatura , Zea mays/metabolismo , Zeína/metabolismo
6.
Mar Drugs ; 19(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922254

RESUMO

This paper presents a comparative study on chitosan degradation in organic acid solutions according to their different dissociation characteristics. More precisely, the aim of the study was to determine the kinetics of the degradation process depending on the different acid dissociation constants (pKa values). The scientists involved in chitosan to date have focused mainly on acetic acid solutions. Solutions of lactic, acetic, malic, and formic acids in concentrations of 3% wt. were used in this research. The progress of degradation was determined based on the intrinsic viscosity measurement, GPC/SEC chromatographic analysis, and their correlation. Changes in the viscosity parameters were performed at a temperature of 20 °C ± 1 °C and a timeframe of up to 168 h (7 days). The chemical structure and DDA of the initial chitosan were analyzed using 1H-NMR spectroscopy analysis. The results of this study can be considered of high importance for the purpose of electrospinning, production of micro- and nano-capsules for drug delivery, and other types of processing. Understanding the influence of the dissociation constant of the solvent on the kinetics of chitosan degradation will allow the selection of an appropriate medium, ensuring an effective and stable spinning process, in which the occurrence of polymer degradation is unfavorable.


Assuntos
Ácidos/química , Quitosana/química , Concentração de Íons de Hidrogênio , Cinética , Estrutura Molecular , Temperatura , Viscosidade
7.
Molecules ; 26(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33804158

RESUMO

An artificial neural network model is proposed for the surface tension of liquid organic fatty acids covering a wide temperature range. A set of 2051 data collected for 98 acids (including carboxylic, aliphatic, and polyfunctional) was considered for the training, testing, and prediction of the resulting network model. Different architectures were explored, with the final choice giving the best results, in which the input layer has the reduced temperature (temperature divided by the critical point temperature), boiling temperature, and acentric factor as an independent variable, a 41-neuron hidden layer, and an output layer consisting of one neuron. The overall absolute percentage deviation is 1.33%, and the maximum percentage deviation is 14.53%. These results constitute a major improvement over the accuracy obtained using corresponding-states correlations from the literature.


Assuntos
Ácidos/química , Compostos Orgânicos/química , Redes Neurais de Computação , Tensão Superficial , Temperatura
8.
Nat Commun ; 12(1): 2405, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33893305

RESUMO

Kidney intercalated cells are involved in acid-base homeostasis via vacuolar ATPase expression. Here we report six human intercalated cell subtypes, including hybrid principal-intercalated cells identified from single cell transcriptomics. Phagosome maturation is a biological process that increases in biological pathway analysis rank following exposure to uropathogenic Escherichia coli in two of the intercalated cell subtypes. Real time confocal microscopy visualization of murine renal tubules perfused with green fluorescent protein expressing Escherichia coli or pHrodo Green E. coli BioParticles demonstrates that intercalated cells actively phagocytose bacteria then acidify phagolysosomes. Additionally, intercalated cells have increased vacuolar ATPase expression following in vivo experimental UTI. Taken together, intercalated cells exhibit a transcriptional response conducive to the kidney's defense, engulf bacteria and acidify the internalized bacteria. Intercalated cells represent an epithelial cell with characteristics of professional phagocytes like macrophages.


Assuntos
Células Epiteliais/imunologia , Rim/imunologia , Fagócitos/imunologia , Escherichia coli Uropatogênica/imunologia , Ácidos/química , Animais , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica/métodos , Humanos , Rim/citologia , Rim/metabolismo , Túbulos Renais Coletores/citologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia Confocal , Fagócitos/citologia , Análise de Célula Única/métodos , ATPases Vacuolares Próton-Translocadoras/metabolismo
9.
Molecules ; 26(4)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671348

RESUMO

The prediction of the aqueous pKa of carbon acids by Quantitative Structure Property Relationship or cheminformatics-based methods is a rather arduous problem. Primarily, there are insufficient high-quality experimental data points measured in homogeneous conditions to allow for a good global model to be generated. In our computationally efficient pKa prediction method, we generate an atom-type feature vector, called a distance spectrum, from the assigned ionisation atom, and learn coefficients for those atom-types that show the impact each atom-type has on the pKa of the ionisable centre. In the current work, we augment our dataset with pKa values from a series of high performing local models derived from the Ab Initio Bond Lengths method (AIBL). We find that, in distilling the knowledge available from multiple models into one general model, the prediction error for an external test set is reduced compared to that using literature experimental data alone.


Assuntos
Ácidos/química , Carbono/química , Modelos Químicos , Concentração de Íons de Hidrogênio
10.
Molecules ; 26(4)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670177

RESUMO

For centuries, natural medicines have represented the only option for treating human diseases and, nowadays, plant phytochemicals are considered as promising compounds to treat or prevent chronic conditions. Among them, hop flowers (Humulus lupulus L.), typically used in brewing industries to give the typical aroma and flavor to beer, have attracted particular attention for their health promoting properties. Several in vivo/vitro studies and human interventional trials have demonstrated the beneficial effects of these molecules on weight gain, lipid metabolism, glucose homeostasis, insulin sensitivities, and inflammation by acting on different targets. All these activities suggest a possible role of bitter hop acid in preventing metabolic syndrome and its related diseases. A systematic quest on PubMed and Scopus databases was performed to identify pre-clinical and clinical studies focusing on this topic. This systematic review summarizes the results obtained by different cell lines, animal models, and human interventional trials to propose iso-α-acids as medical nutrition therapy to treat or prevent metabolic syndrome and its related disorders as diabetes, dislipidemia inflammation, etc.


Assuntos
Diabetes Mellitus/tratamento farmacológico , Humulus/química , Inflamação/tratamento farmacológico , Síndrome Metabólica/tratamento farmacológico , Ácidos/química , Ácidos/uso terapêutico , Cerveja , Flores/química , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia
11.
J Med Chem ; 64(6): 3197-3203, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33685125

RESUMO

The polar-π effect on tetrazoles, medicinal chemistry isosteres of carboxylate, is tested by a Hammett pKa (microtitration) analysis over a series of 5-(m-terphenyl-2'-yl)-1H-tetrazoles. A comparison with m-terphenyl-2'-yl-carboxylic acids supports the isostere analogy also in response to environmental changes. Computational (B97D/def2TZVPPD) extension of the series plus a scan of solvents (vacuum to water) demonstrates the trend with the dielectric constant. The effect is energetically small but may make statistically significant contributions to the tetrazole pharmacological profile.


Assuntos
Ácidos Carboxílicos/química , Compostos de Terfenil/química , Tetrazóis/química , Ácidos/química , Modelos Moleculares , Compostos de Terfenil/síntese química , Tetrazóis/síntese química , Termodinâmica
12.
Food Chem ; 355: 129472, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33780791

RESUMO

In this work, hydroxybutyl starch prepared by acid, alkali, and acid-base synergistic pretreatments from waxy corn starch exhibited great potential for preparing temperature-sensitive hydrogels. The degree of substitution, morphology, and group structure of hydroxybutyl starch were determined. The hydroxybutyl starch prepared by acid-base synergistic pretreatment had the highest degree of substitution. Relative to the native starch, the surface of hydroxybutyl starch particles was smoother and rounder. The formation, microstructure, and properties of temperature-sensitive hydrogels were also determined in this work. The results indicated that the temperature-sensitive hydrogels containing hydroxybutyl starch had irregular pore structures and higher water absorption rates. As the starch content increased, the pore size of these hydrogels increased and then decreased, the water absorption rate increased and the deswelling rate decreased. The equilibrium swelling ratio of the hydrogel prepared by hydroxybutyl starch was greater than that of native starch.


Assuntos
Hidrogéis/química , Amido/química , Ácidos/química , Adsorção , Álcalis/química , Porosidade , Temperatura , Água/química , Zea mays/metabolismo
13.
Carbohydr Polym ; 261: 117879, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766366

RESUMO

A neutral polysaccharide (HJP-1a) and three acid polysaccharides (HJP-2, HJP-3 and HJP-4) were obtained from Z. jujuba cv. Hamidazao. HJP-1a was mainly composed of arabinose and galactose in a ratio of 56.9:20.0, with an average molecular weight of 3.115 × 104 g/mol. HJP-2, HJP-3 and HJP-4 were homogeneous heteropolysaccharides mainly containing galacturonic acid, arabinose and galactose, with average molecular weights of 4.590 × 104, 6.986 × 104 and 1.951 × 105 g/mol, respectively. Structural characterization indicated that the backbone of HJP-3 appeared to be mainly composed of →4)-α-d-GalpA (1→ and →2,4)-α-l-Rhap (1→ residues with some branches consisting of →5)-α-l-Araf (1→ residues and terminals of T-α-l-Araf (1→ and T-ß-d-Galp residues. The four purified fractions displayed dose-dependent radical scavenging activity on ABTS+ radicals and reducing capacity, as well as excellent protective effect on H2O2-induced HepG2 cells and metronidazole-damaged zebrafish embryos, especially HJP-2 in vitro and HJP-1a in vivo. Therefore, the polysaccharides from Z. jujuba cv. Hamidazao could be used as a potential antioxidant in functional foods.


Assuntos
Antioxidantes , Polissacarídeos , Ziziphus/química , Ácidos/química , Ácidos/farmacologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Carboidratos da Dieta/análise , Carboidratos da Dieta/isolamento & purificação , Carboidratos da Dieta/farmacologia , Feminino , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Masculino , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Peixe-Zebra
14.
Chem Pharm Bull (Tokyo) ; 69(3): 258-264, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33642473

RESUMO

The degradation behavior of eight benzodiazepines (BZPs): alprazolam, etizolam, diazepam, triazolam, nitrazepam (NZP), flunitrazepam (FNZ), bromazepam, and lorazepam, in artificial gastric juice was monitored by a LC/photodiode array detector (PDA) to estimate their pharmacokinetics in the stomach. For drugs that were degradable, such physicochemical parameters as reaction rate constant were measured to evaluate the effect of storage conditions on drug degradability, such as whether the degradation proceeds faster by increasing storage temperature, or whether the degradation reaction is reversible by adjusting pH. As a result, it was confirmed that although the eight BZPs degraded in artificial gastric juice, most of them could be restored when pH was increased, and the restoration rates differed depending on the pH and the type of BZP. As for NZP, an Arrhenius plot was drawn to obtain the physicochemical parameters, such as activation energy and activation entropy involved in the degradation reaction, and the reaction kinetics was discussed. In addition, two substances were confirmed as the degradation products of NZP in artificial gastric juice: one was a reversible degradation product (A) (intermediate) and the other was an irreversible degradation product (B) (final degradation product). The intermediate was identified as 2-amino-N-(2-benzoyl-4-nitrophenyl)-acetamide, and the final degradation product was 2-amino-5-nitrobenzophenone. Therefore, when detecting NZP in human stomach contents, such as during judicial dissection, it would be prudent to target NZP as well as the intermediate (A) and the final degradation product (B).


Assuntos
Benzodiazepinas/química , Suco Gástrico/química , Nitrazepam/química , Ácidos/química , Benzofenonas/química , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Humanos , Hidrólise , Preparações Farmacêuticas/química , Estômago , Espectrometria de Massas em Tandem
15.
Int J Biol Macromol ; 181: 291-300, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33775760

RESUMO

The purpose of this work was to evaluate the effect of itaconation on sizing properties (such as viscosity stability, adhesion and film properties) of biological macromolecule (corn starch) for developing a new bio-based sizing agent [itaconylated starch (IS)]. Granular IS samples were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The adhesion of IS to wool fibers was investigated by a standard method (FZ/T 15001-2008). And film properties of IS samples were also studied in terms of tensile strength, breaking elongation, bending endurance and degree of crystallinity, etc. Compared with control acid-converted starch (ACS), stronger bonding forces to wool fibers for IS as well as higher breaking elongation and lower tensile strength for IS film were displayed. Increasing the degrees of substitution (DS) of IS samples from 0 to 0.052 was able to achieve gradually enhanced bonding forces, breaking elongation and bending endurance, which implied that increasing the number of itaconate substituents could play a significantly positive role in overcoming the shortcomings (insufficient adhesion and film brittleness) of starch. These experimental results denoted that the granular IS exhibited potential for the use as a new starch-based size in the sizing of wool warp yarns.


Assuntos
Amido/química , Succinatos/química , Fibra de Lã/análise , Ácidos/química , Adesividade , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/ultraestrutura , Tensão Superficial , Resistência à Tração , Viscosidade , Molhabilidade , Difração de Raios X
16.
Int J Biol Macromol ; 180: 625-632, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766589

RESUMO

The formation and structural evolution of starch nanocrystals from waxy maize starch (WMS) and waxy potato starch (WPS) by acid hydrolysis were studied. The relative crystallinity, the short-range molecular order, and the double-helix content of WMS and WPS increased significantly during the initial stage of acid hydrolysis, indicating that acid preferentially eroded the amorphous regions of starch granules. With time, there was increased destruction of lamellar structures, causing the granules to completely disintegrate to form nanocrystals. WMS and WPS displayed different hydrolysis mechanisms. WPS was more susceptible to acid hydrolysis than WMS, and WMS exhibited an endo-corrosion pattern and WPS showed an exo-corrosion pattern. WMS nanocrystals had a parallelepiped shape, and WPS nanocrystals were round. This difference in shape is likely due to the different packing configuration of double helices in native starches.


Assuntos
Nanopartículas/química , Solanum tuberosum/química , Amido/química , Ceras/química , Zea mays/química , Ácidos/química , Amilopectina/química , Amilopectina/metabolismo , Amilose/química , Amilose/metabolismo , Hidrólise , Microscopia Eletrônica de Varredura/métodos , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Espalhamento a Baixo Ângulo , Solanum tuberosum/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/metabolismo , Amido/ultraestrutura , Ceras/metabolismo , Difração de Raios X , Zea mays/metabolismo
17.
Int J Mol Sci ; 22(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557223

RESUMO

Few scientific reports have suggested the possibility of using natural phenolic acids as functional substances, such as stabilizers for polymeric materials. The replacement of commercial stabilizers in the polymer industry can be beneficial to human health and the environment. The aim of this study was to obtain biodegradable composition of polylactide (PLA) and polyhydroxyalkanoate (PHA) with natural amber (succinic) acid. The materials were subjected to controlled thermooxidation and solar aging. The research methodology included thermal analysis, examination of surface energy, mechanical properties and spectrophotometric analysis of the color change after aging. The samples of aliphatic polyesters containing from 1 to 2 parts by weight of succinic acid were characterized by increased resistance to oxidation (DSC analysis). Natural acid, preferably at a concentration of 1-1.5 parts by weight, acted as a stabilizer in the polymer compositions. On the other hand, materials that had amber acid above 2 parts by weight added were more susceptible to oxidation (DSC). They also showed the lowest aging coefficients (K). The addition of acid at 2.5-4 parts by weight caused a pro-oxidative effect and accelerated aging. By adding amber acid to PLA and PHA, it is possible to design their time in service and their overall lifetime.


Assuntos
Ácidos/química , Materiais Biocompatíveis/química , Produtos Biológicos/química , Polímeros/química , Varredura Diferencial de Calorimetria , Macrófagos/imunologia , Macrófagos/metabolismo , Oxirredução , Ácido Succínico/química , Temperatura , Termogravimetria
18.
Int J Biol Macromol ; 172: 10-18, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33388320

RESUMO

Wastewater contaminated with dyes is discharged by huge amount daily, and involved many hazardous materials. Thus, this study focused on introducing low cost, ecofriendly and available removal agent (lignin-based adsorbent). Three adsorbents, APKL-4, APKL-5 and APKL-6 were obtained using gradient acid precipitation technology and used for methylene blue (MB) removal. The samples were characterized by SEM, FT-IR and zeta potential analyzer. The results indicated that the three adsorbents exhibit significantly different adsorption behavior due to the structural differences caused by fractionation. The APKL-5 and APKL-6 have fewer hydrophilic groups in their molecules and thus have more adsorption active sites to load MB molecules. A pore structure inside of APKL-5 molecules is form in acid fractionation, which allows it to carry more MB molecules. The adsorption capacity of APKL-5 increased 3.8 times (from 345 to 1310 mg g-1) in the alkaline solution which showing excellent pH responsiveness. This paper presents a new promising approach for preparing high efficiency, low cost and eco-friendly adsorbents and builds a foundation for developing further applications of lignin-based adsorbents.


Assuntos
Ácidos/química , Fracionamento Químico/métodos , Corantes/química , Lignina/química , Adsorção , Cinética , Azul de Metileno/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
19.
Nat Commun ; 12(1): 526, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483514

RESUMO

Aciduric bacteria that can survive in extremely acidic conditions (pH < 4.0) are challenging to the current antimicrobial approaches, including antibiotics and photodynamic bacteria inactivation (PDI). Here, we communicate a photosensitizer design concept of halogenation of fluorescein for extremely acidic PDI. Upon halogenation, the well-known spirocyclization that controls the absorption of fluorescein shifts to the acidic pH range. Meanwhile, the heavy atom effect of halogens boosts the generation of singlet oxygen. Accordingly, several photosensitizers that could work at even pH < 2.0 were discovered for a broad band of aciduric bacteria families, with half maximal inhibitory concentrations (IC50) lower than 1.1 µM. Since one of the discovered photosensitizers is an FDA-approved food additive (2',4',5',7'-tetraiodofluorescein, TIF), successful bacteria growth inhibition in acidic beverages was demonstrated, with greatly extended shelf life from 2 days to ~15 days. Besides, the in vivo PDI of Candidiasis with TIF under extremely acidic condition was also demonstrated.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Fluoresceína/farmacologia , Luz , Fármacos Fotossensibilizantes/farmacologia , Ácidos/química , Animais , Bactérias/classificação , Bactérias/efeitos da radiação , Feminino , Fluoresceína/química , Halogenação , Humanos , Concentração de Íons de Hidrogênio , Camundongos Endogâmicos ICR , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Estrutura Molecular , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo
20.
Aquat Toxicol ; 231: 105736, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33422860

RESUMO

Cholinesterases are key enzymes in central and peripheral cholinergic nerve system functioning on nerve impulse transmission in animals. Though cholinesterases have been identified in most vertebrates, the knowledge about the variable numbers and multiple functions of the genes is still quite meagre in invertebrates, especially in scallops. In this study, the complete cholinesterase (ChE) family members have been systematically characterized in Yesso scallop (Patinopecten yessoensis) via whole-genome scanning through in silico analysis. Ten ChE family members in the genome of Yesso scallop (designated PyChEs) were identified and potentially acted to be the largest number of ChE in the reported species to date. Phylogenetic and protein structural analyses were performed to determine the identities and evolutionary relationships of these genes. The expression profiles of PyChEs were determined in all developmental stages, in healthy adult tissues, and in mantles under low pH stress (pH 6.5 and 7.5). Spatiotemporal expression suggested the ubiquitous functional roles of PyChEs in all stages of development, as well as general and tissue-specific functions in scallop tissues. Regulation expressions revealed diverse up- and down-regulated expression patterns at most time points, suggesting different functional specialization of gene superfamily members in response to ocean acidification (OA). Evidences in gene number, phylogenetic relationships and expression patterns of PyChEs revealed that functional innovations and differentiations after gene duplication may result in altered functional constraints among PyChEs gene clusters. Collectively, our results provide the potential clues that the selection pressures coming from the environment were the potential inducement leading to function allocation of ChE family members in scallop.


Assuntos
Ácidos/química , Colinesterases/genética , Regulação Enzimológica da Expressão Gênica , Oceanos e Mares , Pectinidae/enzimologia , Pectinidae/genética , Sequência de Aminoácidos , Animais , Colinesterases/química , Colinesterases/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Genoma , Filogenia , Domínios Proteicos
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