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1.
J Vis Exp ; (167)2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33586706

RESUMO

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pre-treatment on lignocellulosic biomass before using it as source of mechanical reinforcement in fully bio-based fiberboards was developed. Various lignocellulosic crop by-products have already been successfully pre-treated through this process, e.g., cereal straws (especially rice), coriander straw, shives from oleaginous flax straw, and bark of both amaranth and sunflower stems. The extrusion process results in a marked increase in the average fiber aspect ratio, leading to improved mechanical properties of fiberboards. The twin-screw extruder can also be fitted with a filtration module at the end of the barrel. The continuous extraction of various chemicals (e.g., free sugars, hemicelluloses, volatiles from essential oil fractions, etc.) from the lignocellulosic substrate, and the fiber refining can, therefore, be performed simultaneously. The extruder can also be used for its mixing ability: a natural binder (e.g., Organosolv lignins, protein-based oilcakes, starch, etc.) can be added to the refined fibers at the end of the screw profile. The obtained premix is ready to be molded through hot pressing, with the natural binder contributing to fiberboard cohesion. Such a combined process in a single extruder pass improves the production time, production cost, and may lead to reduction in plant production size. Because all the operations are performed in a single step, fiber morphology is better preserved, thanks to a reduced residence time of the material inside the extruder, resulting in enhanced material performances. Such one-step extrusion operation may be at the origin of a valuable industrial process intensification. Compared to commercial wood-based materials, these fully bio-based fiberboards do not emit any formaldehyde, and they could find various applications, e.g., intermediate containers, furniture, domestic flooring, shelving, general construction, etc.


Assuntos
Biotecnologia/instrumentação , Biotecnologia/métodos , Lignina/química , Absorção Fisico-Química , Biomassa , Dessecação , Temperatura Alta , Água/química , Madeira/química
2.
J Pharmacol Exp Ther ; 376(3): 358-373, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33468641

RESUMO

Blebbistatin, para-nitroblebbistatin (NBleb), and para-aminoblebbistatin (AmBleb) are highly useful tool compounds as they selectively inhibit the ATPase activity of myosin-2 family proteins. Despite the medical importance of the myosin-2 family as drug targets, chemical optimization has not yet provided a promising lead for drug development because previous structure-activity-relationship studies were limited to a single myosin-2 isoform. Here we evaluated the potential of blebbistatin scaffold for drug development and found that D-ring substitutions can fine-tune isoform specificity, absorption-distribution-metabolism-excretion, and toxicological properties. We defined the inhibitory properties of NBleb and AmBleb on seven different myosin-2 isoforms, which revealed an unexpected potential for isoform specific inhibition. We also found that NBleb metabolizes six times slower than blebbistatin and AmBleb in rats, whereas AmBleb metabolizes two times slower than blebbistatin and NBleb in human, and that AmBleb accumulates in muscle tissues. Moreover, mutagenicity was also greatly reduced in case of AmBleb. These results demonstrate that small substitutions have beneficial functional and pharmacological consequences, which highlight the potential of the blebbistatin scaffold for drug development targeting myosin-2 family proteins and delineate a route for defining the chemical properties of further derivatives to be developed. SIGNIFICANCE STATEMENT: Small substitutions on the blebbistatin scaffold have beneficial functional and pharmacological consequences, highlighting their potential in drug development targeting myosin-2 family proteins.


Assuntos
Absorção Fisico-Química , Descoberta de Drogas , Compostos Heterocíclicos de 4 ou mais Anéis/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Miosinas/antagonistas & inibidores , Animais , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/toxicidade , Humanos , Simulação de Dinâmica Molecular , Miosinas/química , Conformação Proteica , Ratos , Distribuição Tecidual
3.
Methods Mol Biol ; 2237: 129-139, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33237414

RESUMO

Membrane arrays are a unique array platform option for the detection of multiple analytes or materials simultaneously. Their naturally absorptive properties and near universal use in various laboratory methods make it an excellent source with which to probe multiple factors simultaneously. Any liquid sample type can be probed, from bacterial strains, tissue lysates, secreted proteins, to DNA aptamers. Below, we will describe some considerations in how to print a membrane array and then a specific usage of the membrane arrays as it relates to a sandwich-based antibody array technique for simultaneously detection of secreted proteins in a liquid sample.


Assuntos
Immunoblotting/métodos , Membranas Artificiais , Análise Serial de Proteínas/métodos , Absorção Fisico-Química , Colódio/química , Polivinil/química
4.
Carbohydr Polym ; 253: 117197, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278971

RESUMO

Phomopsis liquidambari is a classical endophytic fungus with great application potential in ecology and agriculture; however, studies on its exopolysaccharides are lacking. Here, we aimed to evaluate the structure and bioactivity of PLN-1, an exopolysaccharide derived from the P. liquidambari NJUSTb1 strain. The structure was elucidated by chromatography/spectral methods and hydrolyzation. Immunomodulation, moisture absorption, and retention properties were investigated after sulfation and carboxymethylation modification. Results showed that PLN-1 contained a linear repeating unit of →[4)-α-d-Glcp-(1→6)-α-d-Glcp-(1→4)-α-d-Glcp-(1→4)-α-d-Glcp-(1→]n, with a molecular weight of 343 kDa. The degrees of substitution of sulfated polysaccharide (S-PLN-1) and carboxymethylated polysaccharide (C-PLN-1) were 1.228 and 0.903, respectively. S-PLN-1 showed stronger moisture absorption and retention properties than PLN (crude EPS), C-PLN1, and PLN-1. Furthermore, PLN, S-PLN-1, and C-PLN-1 stimulated the proliferation of RAW 264.7 cells with no cytotoxicity. The elucidation of PLN-1 in this study paves the way for future applications.


Assuntos
Polissacarídeos Fúngicos/química , Polissacarídeos Fúngicos/farmacologia , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , /química , Absorção Fisico-Química , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Polissacarídeos Fúngicos/isolamento & purificação , Galactose , Glucose , Fatores Imunológicos/isolamento & purificação , Macrófagos/imunologia , Manose , Camundongos , Peso Molecular , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos
5.
Carbohydr Polym ; 253: 117247, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33279002

RESUMO

In this work, we present a novel ex situ modification of bacterial cellulose (BC) polymer, that significantly improves its ability to absorb water after drying. The method involves a single inexpensive and easy-to-perform process of BC crosslinking, using citric acid along with catalysts, such as disodium phosphate, sodium bicarbonate, ammonium bicarbonate or their mixtures. In particular, the mixture of disodium phosphate and sodium bicarbonate was the most promising, yielding significantly greater water capacity (over 5 times higher as compared to the unmodified BC) and slower water release (over 6 times as compared to the unmodified BC). Further, our optimized crosslinked BC had over 1.5x higher water capacity than modern commercial dressings dedicated to highly exuding wounds, while exhibiting no cytotoxic effects against fibroblast cell line L929 in vitro. Therefore, our novel BC biomaterial may find application in super-absorbent dressings, designed for chronic wounds with imbalanced moisture level.


Assuntos
Absorção Fisico-Química , Bandagens , Materiais Biocompatíveis/química , Celulose/química , Reagentes para Ligações Cruzadas/química , Gluconacetobacter xylinus/metabolismo , Polissacarídeos Bacterianos/química , Cicatrização , Animais , Materiais Biocompatíveis/farmacologia , Catálise , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Celulose/farmacologia , Ácido Cítrico/química , Reagentes para Ligações Cruzadas/farmacologia , Fibroblastos/efeitos dos fármacos , Camundongos , Fosfatos/química , Polissacarídeos Bacterianos/farmacologia , Bicarbonato de Sódio/química , Água/química
6.
Carbohydr Polym ; 254: 117324, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357885

RESUMO

Pectin is natural biopolymer derived from various plant sources and its activity is driven by functional groups. Affinity of pectin and chemical interactions of the active sites to chemicals in media determines fate of adjuvant molecules. Pectin is appropriate co-polymer in modulation of drawbacks of other biopolymers such as low glass transition temperature, low water solubility, and susceptibility to human digestive tract. However, functionality of pectin is improved by its optimized complexation with other chemicals especially in food packaging and tissue engineering. In the last decade, several technical and health-related functions of pectin have been studied through which some products designed and marketed progressively. Pectin-based formulations were commercialized in food, medicine, and radioprotection sectors. It is also advised for alleviation of constipation symptoms. Cost-effectiveness of this multifunctional biopolymer compared to the others that are currently used, has introduced it as a potential alternative for the next years.


Assuntos
Constipação Intestinal/tratamento farmacológico , Composição de Medicamentos/métodos , Embalagem de Alimentos/métodos , Gastroenteropatias/tratamento farmacológico , Pectinas/uso terapêutico , Protetores contra Radiação/uso terapêutico , Engenharia Tecidual/métodos , Absorção Fisico-Química , Digestão/efeitos dos fármacos , Humanos , Metais Pesados/química , Pectinas/química , Protetores contra Radiação/química , Solubilidade , Temperatura de Transição
7.
Carbohydr Polym ; 254: 117404, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357892

RESUMO

Solar-driven water steam generation is a promising strategy for seawater desalination and wastewater purification. However, oil contaminants commonly exist in real water resources, which drives us to design and fabricate photothermal materials with high efficient water steam generation and outstanding anti-oil-fouling ability. Herein, we developed a metal-phenolic network-coated cellulose foam (Fe3+/TA@CF), which exhibits not only superb hydrophilicity and underwater lipophobicity, but also achieves high water evaporation rate of ∼1.3 kg m-2 h-1 even in oil-polluted seawater under one sun illumination. In addition, Fe3+/TA@CF is demonstrated to be both anti-oil-fouling and anti-salt-fouling, which benefits to long-term evaporation in practical utilizations. Metal ions and oil contaminants in the condensed water vapor are almost eliminated after purification. We believe that this low-cost, biodegradable Fe3+/TA@CF paves a way for rationally designing and fabricating high-performance evaporator for oil contaminated water purification.


Assuntos
Celulose/química , Ferro/química , Água do Mar/química , Energia Solar , Luz Solar , Taninos/química , Purificação da Água/métodos , Água/química , Absorção Fisico-Química , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Íons/química , Óleos/química , Vapor , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/economia
8.
Food Chem ; 345: 128832, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33338837

RESUMO

In present study, total oil (TO), surface oil (SO), structural oil (STO), penetrated surface oil (PSO), and oil distribution during frying were analyzed. Results showed STO (53.10-75.89%) fraction made up the largest part of TO followed by PSO (36.26-58.28%) and SO (2.59-3.50%), and the proportion of STO in TO decreased with the increasing frying time, while PSO elevated, indicating the higher frying temperature facilitated the formation of less and smaller pore in samples, and thus led to the less oil content. Therefore, effect of pore on oil absorption was further investigated. Results showed there was no significant difference in oil content of samples with initial pore diameter of 0-0.2 mm. While, TO (mainly STO) increased with the increasing initial pore diameter of 0.3-1.2 mm. The bigger initial pore diameter induced bigger pore volume and porosity. Taken together, this study provided new ideas to clarify oil absorption based on pore profiles.


Assuntos
Absorção Fisico-Química , Culinária/métodos , Temperatura Alta , Óleos/química , Solanum tuberosum/química , Propriedades de Superfície
9.
Ecotoxicol Environ Saf ; 209: 111803, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33360216

RESUMO

The development of efficient and sustainable sorbents for emergent oil cleanup has attracted tremendous attention. In this study, the feasibility of enzymatic grafting of octadecylamine (ODA) on corn stalk pith (CSP) by laccase-TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) treatment for enhanced oil-water separation was investigated. The dynamic contact angle tests suggest that the modified CSP (LCSP) had higher hydrophobicity (WCA, 157.2˚) and lipophilicity (OCA, 0˚) than the CSP did. In addition, the introduction of ODA onto the surface of modified CSP was verified by a variety of characterization techniques including SEM, FT-IR, and XPS. Compared with the control, laccase-TEMPO treatment of CSP coupled with octadecylamine grafting greatly improved the oil sorption capacity from 13.24 g/g to 44.25 g/g, while substantially reduced the water sorption capacity from 15.52 g/g to 2.76 g/g. LCSP has fast kinetic (sorption equilibrium reached before 60 min) and high fits to the pseudo-second-order kinetic model. The results obtained in this study reveal the feasibility of using Laccase-TEMPO treatment to graft the ODA onto the surface of CSP, thereby enhancing the rate and capacity of oil separation from oily water. The method and sorbent developed in this study hold promise for green, simple and cost-effective oil cleanup during oil spillage emergency events.


Assuntos
Poluição por Petróleo , Poluentes Químicos da Água/química , Absorção Fisico-Química , Aminas , Interações Hidrofóbicas e Hidrofílicas , Cinética , Lacase , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Poluentes Químicos da Água/análise
10.
Food Chem ; 335: 127629, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32736156

RESUMO

Folate deficiencies are prevalent in countries with insufficient food diversity. Rice fortification is seen as a viable way to improve the daily intake of folates. This work reports an efficient process of rice fortification involving ultrasonic treatment and absorption of the folic acid fortificant. Increased porosity due to sonication allowed the efficient absorption of folic acid into the brown rice kernel up to 5.195 × 104 µg/100 g, a 1,982-fold increase from its inherent content. The absorbed folic acid in brown rice has 93.53% retention after washing and cooking. Fortification of ultrasound-treated milled rice with folic acid was also efficient affording 6.559 × 104 µg/100 g, a 4,054-fold increase from its basal content. The effect of fortification caused a decrease in the thermal and pasting temperatures. The fortification also caused yellow coloration, decrease in hardness, and increase in the adhesiveness of the rice. The resulting fortified brown rice showed improved textural properties favorable for consumers.


Assuntos
Absorção Fisico-Química , Ácido Fólico/química , Alimentos Fortificados/análise , Oryza/química , Ondas Ultrassônicas , Adesividade , Cor , Dureza
11.
PLoS One ; 15(9): e0239493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956424

RESUMO

Deep eutectic solvents (DESs) have received significant attention as potential extracting agents in recent years due to their favorable characteristics including low cost, easy preparation and environmentally safe starting materials. Experimentally screening for highly efficient DESs meeting various requirements for natural gas sweetening remains a challenging task. Thus, an extensive database of estimated Henry's law constants (Hi) and solubilities (xi) of CO2 in 170 different DESs at 25°C has been constructed using the COSMO-RS method to select potential DESs. Based on the COSMO-RS study, three DESs, namely tetrabutylammonium bromide (TBAB)+polyethylene glycol (PEG-8) (on a molar basis 1:4), TBAB+octanoic acid (OCT) (1:4), and methyltriphenylphosphonium bromide (MTPB)+PEG-8 (1:10), were chosen for further experimentation up to 2 bar at 25°C using a vapor-liquid equilibria (VLE) apparatus. Reliable thermophysical properties were determined experimentally, and a detailed equilibrium-based model was developed for one of the glycol-based DESs (i.e., TBAB+PEG-8 (1:4)). This information is an essential prerequisite for carrying out process simulations of natural gas sweetening plants using ASPEN PLUS. The simulation results for the proposed DES were compared to those of monoethylene glycol (MEG). Here, we find that the aqueous TBAB+PEG-8 (1:4) solvent shows ~60% lower total energy consumption and higher CO2 removal when compared to those using the MEG solvent.


Assuntos
Gás Natural/análise , Indústria de Petróleo e Gás/métodos , Polietilenoglicóis/química , Solventes/química , Absorção Fisico-Química , Brometos , Caprilatos , Dióxido de Carbono/análise , Colina , Simulação por Computador , Poluição Ambiental/prevenção & controle , Desenho de Equipamento , Ligação de Hidrogênio , Modelos Químicos , Estrutura Molecular , Indústria de Petróleo e Gás/economia , Indústria de Petróleo e Gás/instrumentação , Oniocompostos , Compostos de Amônio Quaternário , Sais , Temperatura , Termodinâmica , Temperatura de Transição , Compostos de Tritil
12.
Int J Nanomedicine ; 15: 6503-6518, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922013

RESUMO

Objective: A non-lipolysis nanoemulsion (NNE) was designed to reduce the first-pass metabolism of raloxifene (RAL) by intestinal UDP-glucuronosyltransferases (UGTs) for increasing the oral absorption of RAL, coupled with in vitro and in vivo studies. Methods: In vitro stability of NNE was evaluated by lipolysis and the UGT metabolism system. The oral bioavailability of NNE was studied in rats and pigs. Finally, the absorption mechanisms of NNE were investigated by in situ single-pass intestinal perfusion (SPIP) in rats, Madin-Darby canine kidney (MDCK) cells model, and lymphatic blocking model. Results: The pre-NNE consisted of isopropyl palmitate, linoleic acid, Cremophor RH40, and ethanol in a weight ratio of 3.33:1.67:3:2. Compared to lipolysis nanoemulsion of RAL (RAL-LNE), the RAL-NNE was more stable in in vitro gastrointestinal buffers, lipolysis, and UGT metabolism system (p < 0.05). The oral bioavailability was significantly improved by the NNE (203.30%) and the LNE (205.89%) relative to the suspension group in rats. However, 541.28% relative bioavailability was achieved in pigs after oral NNE intake compared to the suspension and had two-fold greater bioavailability than the LNE (p < 0.05). The RAL-NNE was mainly absorbed in the jejunum and had high permeability at the intestine of rats. The results of both SPIP and MDCK cell models demonstrated that the RAL-NNE was absorbed via endocytosis mediated by caveolin and clathrin. The other absorption route, the lymphatic transport (cycloheximide as blocking agent), was significantly improved by the NNE compared with the LNE (p < 0.05). Conclusion: A NNE was successfully developed to reduce the first-pass metabolism of RAL in the intestine and enhance its lymphatic transport, thereby improving the oral bioavailability. Altogether, NNE is a promising carrier for the oral delivery of drugs with significant first-pass metabolism.


Assuntos
Absorção Fisico-Química , Emulsões/química , Lipólise , Nanopartículas/química , Cloridrato de Raloxifeno/metabolismo , Administração Oral , Animais , Disponibilidade Biológica , Transporte Biológico , Sobrevivência Celular , Cães , Emulsões/administração & dosagem , Feminino , Intestinos/fisiologia , Linfa/metabolismo , Células Madin Darby de Rim Canino , Masculino , Polietilenoglicóis , Ratos Sprague-Dawley , Tensoativos/química , Suínos
13.
Chemosphere ; 259: 127487, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32650165

RESUMO

Polycyclic Aromatic Hydrocarbons (PAHs) have elicited increasing concern due to their ubiquitous occurrence in coastal marine environments and resultant toxicity in organisms. Due to their lipophilic nature, PAHs tend to accumulate in phytoplankton cells and thus subsequently transfer to other compartments of the marine ecosystem. The intrinsic fluorescence properties of PAHs in the ultraviolet (UV)/blue spectral range have recently been exploited to investigate their uptake modes, localization, and aggregation in various biological tissues. Here, we quantitatively evaluate the sorption of two model PAHs (phenanthrene and pyrene) in three marine phytoplankton species (Chaetoceros tenuissimus, Thalassiosira sp. and Proteomonas sp.) using a combined approach of UV excitation flow cytometry and fluorescence microscopy. Over a 48-h exposure to a gradient of PAHs, Thalassiosira sp. showed the highest proportion of PAH-sorbed cells (29% and 97% of total abundance for phenanthrene and pyrene, respectively), which may be attributed to its relatively high total lipid content (33.87 percent dry weight). Moreover, cell-specific pulse amplitude modulation (PAM) microscope fluorometry revealed that PAH sorption significantly reduced the photosynthetic quantum efficiency (Fv/Fm) of individual phytoplankton cells. We describe a rapid and precise hybrid method for the detection of sorption of PAHs on phytoplankton cells. Our results emphasize the ecologically relevant sub-lethal effects of PAHs in phytoplankton at the cellular level, even at concentrations where no growth inhibition was apparent. This work is the first study to address the cell-specific impacts of fluorescent toxicants in a more relevant toxicant-sorbed subpopulation; these cell-specific impacts have to date been unidentified in traditional population-based phytoplankton toxicity assays.


Assuntos
Fitoplâncton/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Análise de Célula Única/métodos , Absorção Fisico-Química , Ecossistema , Citometria de Fluxo/métodos , Microscopia de Fluorescência/métodos , Fenantrenos/química , Fenantrenos/farmacocinética , Fitoplâncton/citologia , Fitoplâncton/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Pirenos/química , Pirenos/farmacocinética , Raios Ultravioleta
14.
Chemosphere ; 257: 127235, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32505955

RESUMO

Effluent organic matter (EfOM) from municipal wastewater treatment plants (WWTPs) has received increasing attention due to its impacts on natural and engineered aquatic systems. A comprehensive understanding of molecular compositions of EfOM is crucial for controlling its negative effects and effective removal of it. Fourier transform-ion cyclotron resonance mass spectrometry (FTICR MS) is a powerful method to characterize molecular compositions of EfOM. However, application of this powerful technique is very depending on the sample preparation procedures (i.e. solid phase extraction, SPE) for enrichment and desalting. In this study, a systematic comparison of the difference in molecular compositions of the EfOM extracted using eighteen different SPE sorbents (Envicarb, PPL, ENV, HLB, C18, C18OH, C8, PH, CH, WAX, WCX, MAX, MCX, CBA, C2, CN-E, NH2, and SI) was investigated. Molecular characterization using FTICR MS showed that non-polar sorbents (Envicarb, PPL, ENV, HLB, C18, C18OH) and mixed mode sorbents (WAX, WCX, MAX, MCX) prefer to extract more aromatic and unsaturated molecules, while strongly-polar (SI), mid-polar (CBA, NH2), and weakly non-polar (C2, CN-E) sorbents prefer to extract more aliphatic components. In addition, it is found that combining extracts of CBA, ENV, and EnviCarb sorbents might be a practical way to provide a comprehensive information of molecular composition of EfOM. The results reported in this study provide valuable information on molecular compositions of EfOM and the selectivity of EfOM by different SPE sorbents.


Assuntos
Absorção Fisico-Química , Águas Residuárias/química , Espectrometria de Massas/métodos , Extração em Fase Sólida/métodos , Eliminação de Resíduos Líquidos
15.
Soft Matter ; 16(21): 5044-5053, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32452496

RESUMO

Conventional approaches to mitigate fouling of membrane surfaces impart hydrophilicity to the membrane surface, which increases the water of hydration and fluidity near the surface. By contrast, we demonstrate here that tuning the membrane surface energy close to that of the dispersive component of water surface tension (21.8 mN m-1) can also improve the antifouling properties of the membrane. Specifically, ultrafiltration (UF) membranes were first modified using polydopamine (PDA) followed by grafting of amine-terminated polysiloxane (PSi-NH2). For example, with 2 g L-1 PSi-NH2 coating solution, the obtained coating layer contains 53% by mass fraction PSi-NH2 and exhibits a total surface energy of 21 mN m-1, decreasing the adsorption of bovine serum albumin by 44% compared to the unmodified membrane. When challenged with 1 g L-1 sodium alginate in a constant-flux crossflow system, the PSi-NH2-grafted membrane exhibits a 70% lower fouling rate than the pristine membrane at a water flux of 110 L (m2 h)-1 and good stability when cleaned with NaOH solutions.


Assuntos
Incrustação Biológica/prevenção & controle , Membranas Artificiais , Siloxanas/química , Absorção Fisico-Química , Alginatos/química , Indóis/química , Polímeros/química , Soroalbumina Bovina/química , Ultrafiltração/métodos , Purificação da Água/métodos
16.
ACS Nano ; 14(5): 6339-6347, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32329337

RESUMO

The emergence of a pandemic affecting the respiratory system can result in a significant demand for face masks. This includes the use of cloth masks by large sections of the public, as can be seen during the current global spread of COVID-19. However, there is limited knowledge available on the performance of various commonly available fabrics used in cloth masks. Importantly, there is a need to evaluate filtration efficiencies as a function of aerosol particulate sizes in the 10 nm to 10 µm range, which is particularly relevant for respiratory virus transmission. We have carried out these studies for several common fabrics including cotton, silk, chiffon, flannel, various synthetics, and their combinations. Although the filtration efficiencies for various fabrics when a single layer was used ranged from 5 to 80% and 5 to 95% for particle sizes of <300 nm and >300 nm, respectively, the efficiencies improved when multiple layers were used and when using a specific combination of different fabrics. Filtration efficiencies of the hybrids (such as cotton-silk, cotton-chiffon, cotton-flannel) was >80% (for particles <300 nm) and >90% (for particles >300 nm). We speculate that the enhanced performance of the hybrids is likely due to the combined effect of mechanical and electrostatic-based filtration. Cotton, the most widely used material for cloth masks performs better at higher weave densities (i.e., thread count) and can make a significant difference in filtration efficiencies. Our studies also imply that gaps (as caused by an improper fit of the mask) can result in over a 60% decrease in the filtration efficiency, implying the need for future cloth mask design studies to take into account issues of "fit" and leakage, while allowing the exhaled air to vent efficiently. Overall, we find that combinations of various commonly available fabrics used in cloth masks can potentially provide significant protection against the transmission of aerosol particles.


Assuntos
Aerossóis/química , Filtração/normas , Máscaras/normas , Dispositivos de Proteção Respiratória/normas , Têxteis/normas , Absorção Fisico-Química , Eletricidade Estática , Têxteis/classificação
17.
J Chromatogr A ; 1622: 461120, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32345440

RESUMO

The characterisation of the energetic properties of liquid crystals, i.e., esters with elongated molecules has been performed. The changes of the free energies of adsorption and absorption (dissolutions), ΔG, for liquid crystals have been estimated, based on the retention times of the centre of gravity of the elution peaks determined for the substances with defined physicochemical properties. The temperature-dependent van der Waals component of the free energy, [Formula: see text] , for a crystalline form of liquid crystal has been estimated by employing the Dorris-Gray approach. These approaches have been widened to mesophases, namely, the absorption(dissolution) of n-alkanes in the smectic B and nematic phases.


Assuntos
Benzoatos/química , Absorção Fisico-Química , Adsorção , Alcanos/química , Cromatografia Gasosa , Entropia , Temperatura
18.
Farm. hosp ; 44(1): 16-19, ene.-feb. 2020. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-187487

RESUMO

Objetivo: La administración intrapleural de fibrinolíticos y dornasa alfa ha demostrado en estudios aleatorizados ser capaz de disminuir la necesidad de desbridamiento quirúrgico del empiema y los días de estancia media hospitalaria. Sin embargo, su aplicación en práctica clínica es limitada, probablemente debido a la falta de protocolos que simplifiquen su administración. El presente estudio tiene como objetivo analizar la estabilidad fisicoquímica de la administración simultánea de uroquinasa y dornasa alfa para el posterior desarrollo de un protocolo de uso en práctica clínica. Método: Ensayo de estabilidad in vitro de uroquinasa, dornasa alfa y la mezcla de ambos. Se evaluó su estabilidad como (i) ausencia de partículas, (ii) variación de color y (iii) cambios de pH a tiempos 0,30 minutos, 1, 2 y 4 horas a 37°C. Cada muestra se preparó y analizó por triplicado. Resultados: Las soluciones individuales de uroquinasa y dornasa alfa mostraron cambios ligeros del pH, sin cambios en su color ni presencia de partículas en suspensión. La mezcla de uroquinasa y dornasa alfa no fue estable transcurridas 2 horas, mostrando turbidez por la floculación y separación de fases con formación de precipitado a las 4 horas. Se desarrolló un protocolo de uso clínico basado en la administración secuencial de uroquinasa y dornasa alfa, ya que no fue posible garantizar la estabilidad fisicoquímica de la administración simultánea de ambos fármacos. Conclusiones: Los datos de estabilidad fisicoquímica no permiten asegurar la administración simultánea de ambos fármacos de manera segura y eficaz, por lo que se propone un protocolo de administración secuencial


Objective: Intrapleural administration of fibrinolytics and dornase alfa has been shown in randomized studies to be able to reduce both the need for surgical debridement of empyema and the average hospital stay. However, its application in clinical practice is limited, probably due to the lack of protocols that simplify its administration. The present study aims to analyze the physicochemical stability of the simultaneous urokinase and dornase alfa administration for the subsequent development of a clinical practice use protocol. Method: In vitro stability test of urokinase, dornase alfa and a combination of both. Its stability was evaluated as (i) absence of particles, (ii) color variation and (iii) pH changes at times 0,30 minutes, 1,2 and 4 hours at 37°C. Each sample was prepared and analyzed in triplicate. Results: Individual solutions of urokinase and dornase alfa showed slight changes in pH, finding no changes in either color or presence of suspended particles. The urokinase and dornase alfa combination was not stable after 2 hours, when turbidity emerged due to flocculation and phase separation. After 4 hours, precipitate formation was found. A protocol for clinical use was developed based on urokinase and dornase alfa sequential administration, since it was not possible to guarantee the physicochemical stability of the simultaneous administration of both drugs. Conclusions: The physicochemical stability data obtained does not allow to ensure a simultaneous administration of both drugs in a safe and effective way, thus a sequential administration protocol is proposed


Assuntos
Técnicas In Vitro , Fibrinolíticos/administração & dosagem , Empiema/tratamento farmacológico , Absorção Fisico-Química , Desoxirribonuclease I/efeitos dos fármacos , Desoxirribonucleases/análise , Derrame Pleural/tratamento farmacológico , Empiema/diagnóstico por imagem
19.
Chemosphere ; 246: 125785, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927374

RESUMO

We have developed a facile one pot process to synthesize an ultra-light functionalized spongy graphene (FSG). This is the first approach to use carbon based flame retardant spongy material as an electrode to build completely flame retardant supercapacitor (FRS) also as an oil/organic solvent absorber. The fully FRS concept has created by the compilation of as-prepared FSG with flame retardant separator and electrolyte. As-prepared FSG contained high amount of phosphorus and nitrogen functional groups, which makes it potent flame retardant electrochemical material, to use it as an efficient FR electrode. Flame test of FSG revealed that it doesn't catch fire for ∼1500 s. Also, FSG was able to sustain flame retardancy at a temperature as high as 1500 °C for continuous exposure of ∼300 s. FSG used as an electrode for symmetric capacitor possessing maximum specific capacitance of 494.3 F g-1 at a current density 1 A g-1. Corresponding high energy density and power density values are 55.6 Wh kg-1 and 1799 W kg-1. It shows cycling stability of 86.1% after 5000 cycles at current density of 10 A g-1. The electrochemical property of FSG was also confirmed using three electrode system. Flame retardant FSG material was also used for the absorption and recovery of oil and organic solvents. FSG has high oil and organic solvent sorption capacity in the range of 40-70 g/g, also can be reused for minimum 10 cycles. Such approach has great significance for multifunctional graphene based nanocomposites will open the new window for large-scale applications.


Assuntos
Eletrodos , Retardadores de Chama/análise , Modelos Químicos , Absorção Fisico-Química , Carbono/química , Grafite/química , Nanocompostos/química , Nitrogênio , Solventes
20.
Int J Biol Macromol ; 147: 187-193, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31917218

RESUMO

In this study, acrylic acid (AA) and cellulose nanofibers (CNFs) were used as main materials to synthesize an acrylic-nanocellulose hybrid hydrogel nanocomposite in the presence of urea. The interpenetrating polymer networks were obtained by radical polymerization in different urea: AA ratios (0:10, 1:10, 3:10, 5:10, 10:10). Fourier transform infrared spectroscopy (FTIR) combined with X-ray diffraction (XRD) and elemental analysis techniques confirmed the chemical interaction of urea in the network structure. Free absorption and water absorption under load (AUL) of the synthesized hydrogels varying in urea: acrylic acid weight ratios were measured in distilled water and saline (0.9 wt%) solution for hybrid (5 wt% CNFs) and pure polyacrylic acid (0 wt% CNFs) hydrogels. It was found that incorporation of urea and CNFs in the hybrid structure generating compact hydrogel networks with high crosslink density leading to lower absorption with and without pressure, whereas incorporation of urea in the structure resulted in a more extended network with higher absorption capacity (about 3×) than hybrid structure.


Assuntos
Acrilatos/química , Celulose/química , Nanogéis/química , Ureia/química , Absorção Fisico-Química , Resinas Acrílicas , Nanofibras/química , Nanofibras/ultraestrutura , Nanogéis/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Difração de Raios X
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