Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 13.995
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Water Sci Technol ; 89(9): 2512-2522, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38747964

RESUMO

This manuscript presents a novel approach for developing an environmentally friendly and effective oil-water separation membrane. Achieving a superhydrophobic (SH) coating on textile fabric (TF) involved a two-step process. Initially, the surface roughness was enhanced by applying bio-zinc oxide (ZnO) nanoparticles obtained from Thymbra spicata L. Subsequently, the roughened surface was modified with stearic acid, a material known for its low surface energy. The bio-ZnO nanoparticles exhibit a circular morphology with an average size of 21 nm. The coating demonstrated remarkable mechanical stability, maintaining SH properties even after an abrasion length of 300 mm. Chemical stability studies revealed that the prepared membrane retained SH properties within a pH range of 5-11, which ensures robust performance. Absorption capacity measurements showcased different capacities for n-hexane (Hex), corn oil (C.O), and silicone oil (S.O), with consistent performance over 10 absorption-desorption cycles. High oil-water separation efficiencies were achieved for hexane, C.O, and S.O, emphasizing the coating's versatility. Flux rate measurements demonstrated that oil passed through the membrane efficiently, with the highest flux observed for Hex. The prepared SH membrane has superior mechanical and chemical stability and high separation efficiencies, which positions it as a promising candidate for diverse industrial applications.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Óxido de Zinco , Óxido de Zinco/química , Água/química , Óleos/química
2.
Molecules ; 29(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38731414

RESUMO

Consumers are concerned about employing green processing technologies and natural ingredients in different manufacturing sectors to achieve a "clean label" standard for products and minimize the hazardous impact of chemical ingredients on human health and the environment. In this study, we investigated the effects of gelatinized starch dispersions (GSDs) prepared from six plant sources (indica and japonica rice, wheat, corn, potatoes, and sweet potatoes) on the formulation and stability of oil-in-water (O/W) emulsions. The effect of gelatinization temperature and time conditions of 85-90 °C for 20 min on the interfacial tension of the two phases was observed. Emulsification was performed using a primary homogenization condition of 10,000 rpm for 5 min, followed by high-pressure homogenization at 100 MPa for five cycles. The effects of higher oil weight fractions (15-25% w/w) and storage stability at different temperatures for four weeks were also evaluated. The interfacial tension of all starch GSDs with soybean oil decreased compared with the interfacial tension between soybean oil and water as a control. The largest interfacial tension reduction was observed for the GSD from indica rice. Microstructural analysis indicated that the GSDs stabilized the O/W emulsion by coating oil droplets. Emulsions formulated using a GSD from indica rice were stable during four weeks of storage with a volume mean diameter (d4,3) of ~1 µm, minimal viscosity change, and a negative ζ-potential.


Assuntos
Emulsões , Óleo de Soja , Amido , Água , Emulsões/química , Amido/química , Água/química , Óleo de Soja/química , Oryza/química , Gelatina/química , Temperatura , Tensão Superficial , Tamanho da Partícula
3.
Molecules ; 29(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38731476

RESUMO

Although the wide variety of bioactivities of curcumin has been reported by researchers, the clinical application of curcumin is still limited due to its poor aqueous solubility. In view of this, a series of dimethylaminomethyl-substituted curcumin derivatives were designed and synthesized (compounds 1-15). Acetate of these derivatives were prepared (compounds 1a-15a). The Mannich reaction and aldol condensation reaction are the main reactions involved in this study. Compounds 6, 10, 12, 3a, 5a, 6a, 7a, 8a, 10a, 11a, 12a, 13a, 14a, and 15a exhibited better in vitro anti-inflammatory activity compared to curcumin in the RAW264.7 cell line. Compounds 5, 1a, 5a, 8a, and 12a exhibited better in vitro antioxidant activity compared to curcumin in the PC 12 cell line. Compounds 11, 13, 5a, 7a, and 13a exhibited better in vitro radiation protection compared to curcumin in the PC 12 cell line. The aqueous solubilities of all the curcumin derivative acetates were greatly improved compared to curcumin.


Assuntos
Anti-Inflamatórios , Antioxidantes , Curcumina , Protetores contra Radiação , Solubilidade , Curcumina/farmacologia , Curcumina/química , Curcumina/síntese química , Curcumina/análogos & derivados , Animais , Camundongos , Antioxidantes/farmacologia , Antioxidantes/química , Antioxidantes/síntese química , Células RAW 264.7 , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/síntese química , Protetores contra Radiação/farmacologia , Protetores contra Radiação/síntese química , Protetores contra Radiação/química , Desenho de Fármacos , Relação Estrutura-Atividade , Estrutura Molecular , Células PC12 , Ratos , Água/química
4.
Food Res Int ; 186: 114374, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729731

RESUMO

As a crucial component of the fungal cell membranes, ergosterol has been demonstrated to possess surface activity attributed to its hydrophobic region and polar group. However, further investigation is required to explore its emulsification behavior upon migration to the oil-water interface. Therefore, this study was conducted to analyze the interface properties of ergosterol as a stabilizer for water in oil (W/O) emulsion. Moreover, the emulsion prepared under the optimal conditions was utilized to load the water-soluble bioactive substance with the chlorogenic acid as the model molecules. Our results showed that the contact angle of ergosterol was 117.017°, and its dynamic interfacial tension was obviously lower than that of a pure water-oil system. When the ratio of water to oil was 4: 6, and the content of ergosterol was 3.5 % (ergosterol/oil phase, w/w), the W/O emulsion had smaller particle size (438 nm), higher apparent viscosity, and better stability. Meanwhile, the stability of loaded chlorogenic acid was improved under unfavorable conditions (pH 1.2, 90 °C, ultraviolet irradiation, and oxidation), which were 73.87 %, 59.53 %, 62.53 %, and 69.73 %, respectively. Additionally, the bioaccessibility of chlorogenic acid (38.75 %) and ergosterol (33.69 %), and the scavenging rates of the emulsion on DPPH radicals (81.00 %) and hydroxyl radicals (82.30 %) were also enhanced. Therefore, a novel W/O Pickering emulsion was prepared in this work using ergosterol as an emulsifier solely, which has great potential for application in oil-based food and nutraceutical formulations.


Assuntos
Ácido Clorogênico , Emulsificantes , Emulsões , Ergosterol , Tamanho da Partícula , Água , Ergosterol/química , Emulsões/química , Emulsificantes/química , Água/química , Ácido Clorogênico/química , Viscosidade , Antioxidantes/química , Óleos/química , Concentração de Íons de Hidrogênio
5.
Food Res Int ; 187: 114452, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38763687

RESUMO

The antioxidant activity of the natural phenolic extracts is limited in particular food systems due to the existence of phenolic compounds in glycoside form. Acid hydrolysis post-treatment could be a tool to convert the glycosidic polyphenols in the extracts to aglycones. Therefore, this research investigated the effects of an acid hydrolysis post-treatment on the composition and antioxidant activity of parsley extracts obtained by an ultrasound-assisted extraction method to delay lipid oxidation in a real food system (i.e., soybean oil-in-water emulsion). Acid hydrolysis conditions were varied to maximize total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. When extracts were exposed to 0.6 M HCl for 2 h at 80 ℃, TPC was 716.92 ± 24.43 µmol gallic acid equivalent (GAE)/L, and DPPH radical scavenging activity was 66.89 ± 1.63 %. Not only did acid hydrolysis increase the concentrations of individual polyphenols, but it also resulted in the release of new phenolics such as myricetin and gallic acid. The extract's metal chelating and ferric-reducing activity increased significantly after acid hydrolysis. In soybean oil-in-water emulsion containing a TPC of 400 µmol GAE/L, the acid-hydrolyzed extract had an 11-day lag phase for headspace hexanal compared to the 6-day lag phase of unhydrolyzed extract. The findings indicated that the conversion of glycosidic polyphenols to aglycones in phenolic extracts can help extend the shelf-life of emulsion-based foods.


Assuntos
Antioxidantes , Emulsões , Petroselinum , Fenóis , Extratos Vegetais , Folhas de Planta , Óleo de Soja , Emulsões/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Óleo de Soja/química , Fenóis/química , Hidrólise , Antioxidantes/farmacologia , Antioxidantes/química , Petroselinum/química , Folhas de Planta/química , Oxirredução , Água/química , Peroxidação de Lipídeos/efeitos dos fármacos , Compostos de Bifenilo/química , Picratos/química , Polifenóis/química , Polifenóis/farmacologia
6.
J Am Chem Soc ; 146(20): 14213-14224, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38739765

RESUMO

The formation of an amide bond is an essential step in the synthesis of materials and drugs, and in the assembly of amino acids to form peptides. The mechanism of this reaction has been studied extensively, in particular to understand how it can be catalyzed, but a representation capable of explaining all the experimental data is still lacking. Numerical simulation should provide the necessary molecular description, but the solvent involvement poses a number of challenges. Here, we combine the efficiency and accuracy of neural network potential-based reactive molecular dynamics with the extensive and unbiased exploration of reaction pathways provided by transition path sampling. Using microsecond-scale simulations at the density functional theory level, we show that this method reveals the presence of two competing distinct mechanisms for peptide bond formation between alanine esters in aqueous solution. We describe how both reaction pathways, via a general base catalysis mechanism and via direct cleavage of the tetrahedral intermediate respectively, change with pH. This result contrasts with the conventional mechanism involving a single pathway in which only the barrier heights are affected by pH. We show that this new proposal involving two competing mechanisms is consistent with the experimental data, and we discuss the implications for peptide bond formation under prebiotic conditions and in the ribosome. Our work shows that integrating deep potential molecular dynamics with path sampling provides a powerful approach for exploring complex chemical mechanisms.


Assuntos
Simulação de Dinâmica Molecular , Peptídeos , Água , Água/química , Peptídeos/química , Teoria da Densidade Funcional , Concentração de Íons de Hidrogênio , Alanina/química , Amidas/química
7.
Sci Rep ; 14(1): 11047, 2024 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744989

RESUMO

Callicarpa kwangtungensis Chun (CK) is a common remedy exhibits anti-inflammatory properties and has been used in Chinese herbal formulations, such as KangGongYan tablets. It is the main component of KangGongYan tablets, which has been used to treat chronic cervicitis caused by damp heat, red and white bands, cervical erosion, and bleeding. However, the anti-inflammatory effects of CK water extract remains unknown. This study assessed the anti-inflammatory effects of CK in vivo and in vitro, characterized its main components in the serum of rats and verified the anti-inflammatory effects of serum containing CK. Nitric oxide (NO), tumour necrosis factor α (TNF-α) and interleukin-6 (IL-6) release by RAW264.7 cells was examined by ELISA and Griess reagents. Inflammation-related protein expression in LPS-stimulated RAW264.7 cells was measured by western blotting. Furthermore, rat model of foot swelling induced by λ-carrageenan and a collagen-induced arthritis (CIA) rat model were used to explore the anti-inflammatory effects of CK. The components of CK were characterized by LC-MS, and the effects of CK-containing serum on proinflammatory factors levels and the expression of inflammation-related proteins were examined by ELISA, Griess reagents and Western blotting. CK suppressed IL-6, TNF-α, and NO production, and iNOS protein expression in LPS-stimulated RAW264.7 cells. Mechanistic studies showed that CK inhibited the phosphorylation of ERK, P38 and JNK in the MAPK signaling pathway, promoted the expression of IκBα in the NF-κB signaling pathway, and subsequently inhibited the expression of iNOS, thereby exerting anti-inflammatory effects. Moreover, CK reduced the swelling rates with λ-carrageenan induced foot swelling, and reduced the arthritis score and incidence in the collagen-induced arthritis (CIA) rat model. A total of 68 compounds in CK water extract and 31 components in rat serum after intragastric administration of CK were characterized. Serum pharmacological analysis showed that CK-containing serum suppressed iNOS protein expression and NO, TNF-α, and IL-6 release. CK may be an anti-inflammatory agent with therapeutic potential for acute and chronic inflammatory diseases, especially inflammatory diseases associated with MAPK activation.


Assuntos
Anti-Inflamatórios , Artrite Experimental , Óxido Nítrico , Extratos Vegetais , Animais , Camundongos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Ratos , Células RAW 264.7 , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Óxido Nítrico/metabolismo , Artrite Experimental/tratamento farmacológico , Água/química , Carragenina , Modelos Animais de Doenças , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/sangue , Masculino , Interleucina-6/metabolismo , Interleucina-6/sangue , Edema/tratamento farmacológico , Inflamação/tratamento farmacológico
8.
Chemosphere ; 358: 142198, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38697566

RESUMO

In the electrical industry, there are many hazardous gases that pollute the environment and even jeopardize human health, so timely detection and effective control of these hazardous gases is of great significance. In this work, the gas-sensitive properties of Pd-modified g-C3N4 interface for each hazardous gas molecule were investigated from a microscopic viewpoint, taking the hazardous gases (CO, NOx) that may be generated in the power industry as the detection target. Then, the performance of Pd-modifiedg-C3N4 was evaluated for practical applications as a gas sensor material. Novelly, an unconventional means was designed to briefly predict the effect of humidity on the adsorption properties of this sensor material. The final results found that Pd-modified g-C3N4 is most suitable as a potential gas-sensitizing material for NO2 gas sensors, followed by CO. Interestingly, Pd-modified g-C3N4 is less suitable as a potential gas-sensitizing material for NO gas sensors, but has the potential to be used as a NO cleaner (adsorbent). Unconventional simulation explorations of humidity effects show that in practical applications Pd-modified g-C3N4 remains a promising material for gas sensing in specific humidity environments. This work reveals the origin of the excellent properties of Pd-modified g-C3N4 as a gas sensor material and provides new ideas for the detection and treatment of these three hazardous gases.


Assuntos
Poluentes Atmosféricos , Paládio , Poluentes Atmosféricos/análise , Paládio/química , Adsorção , Água/química , Monitoramento Ambiental/métodos , Gases/análise , Umidade , Monóxido de Carbono/análise , Nitrilas/química , Nitrilas/análise
9.
Nat Commun ; 15(1): 4160, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755128

RESUMO

The regeneration of critical-size bone defects, especially those with irregular shapes, remains a clinical challenge. Various biomaterials have been developed to enhance bone regeneration, but the limitations on the shape-adaptive capacity, the complexity of clinical operation, and the unsatisfied osteogenic bioactivity have greatly restricted their clinical application. In this work, we construct a mechanically robust, tailorable and water-responsive shape-memory silk fibroin/magnesium (SF/MgO) composite scaffold, which is able to quickly match irregular defects by simple trimming, thus leading to good interface integration. We demonstrate that the SF/MgO scaffold exhibits excellent mechanical stability and structure retention during the degradative process with the potential for supporting ability in defective areas. This scaffold further promotes the proliferation, adhesion and migration of osteoblasts and the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. With suitable MgO content, the scaffold exhibits good histocompatibility, low foreign-body reactions (FBRs), significant ectopic mineralisation and angiogenesis. Skull defect experiments on male rats demonstrate that the cell-free SF/MgO scaffold markedly enhances bone regeneration of cranial defects. Taken together, the mechanically robust, personalised and bioactive scaffold with water-responsive shape-memory may be a promising biomaterial for clinical-size and irregular bone defect regeneration.


Assuntos
Materiais Biocompatíveis , Regeneração Óssea , Fibroínas , Magnésio , Células-Tronco Mesenquimais , Osteogênese , Alicerces Teciduais , Fibroínas/química , Fibroínas/farmacologia , Regeneração Óssea/efeitos dos fármacos , Animais , Alicerces Teciduais/química , Masculino , Osteogênese/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Ratos , Magnésio/química , Magnésio/farmacologia , Materiais Biocompatíveis/química , Osteoblastos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Ratos Sprague-Dawley , Água/química , Proliferação de Células/efeitos dos fármacos , Engenharia Tecidual/métodos , Crânio/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Bombyx
10.
An Acad Bras Cienc ; 96(2): e20220448, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38775552

RESUMO

The present study investigated mushroom by-products as a substitute for emulsifiers in the microencapsulation of apricot kernel oil. Mushroom by-product emulsions were more viscous and had higher centrifugal (85.88±1.19 %) and kinetic (90.52±0.98 %) stability than control emulsions (Tween 20 was used as emulsifier). Additionally, spray-drying mushroom by-product emulsions yielded a high product yield (62.56±1.11 %). Furthermore, the oxidative stability of powder products containing mushroom by-products was observed to be higher than that of the control samples. For an accelerated oxidation test, the samples were kept at various temperatures (20, 37, and 60 °C). TOTOX values were assessed as indicators of oxidation, with values exceeding 30 indicating oxidation of the samples. Of the samples stored at 60 °C, the non-microencapsulated apricot kernel oil oxidized by the fifth day (41.12±0.13 TOTOX value), whereas the powder samples containing the mushroom by-products remained unoxidized until the end of the tenth day (37.05±0.08 TOTOX value). This study revealed that mushroom by-products could be a viable alternative for synthetic emulsifiers in the microencapsulation of apricot kernel oil. It has been observed that using mushroom by-products instead of synthetic emulsifiers in oil microencapsulation can also delay oxidative degradation in microencapsulated powders.


Assuntos
Emulsificantes , Emulsões , Óleos de Plantas , Prunus armeniaca , Emulsões/química , Emulsificantes/química , Óleos de Plantas/química , Prunus armeniaca/química , Composição de Medicamentos , Agaricales/química , Oxirredução , Água/química
11.
Sci Adv ; 10(16): eadj7179, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38630826

RESUMO

The formation of protein precursors, due to the condensation of atomic carbon under the low-temperature conditions of the molecular phases of the interstellar medium, opens alternative pathways for the origin of life. We perform peptide synthesis under conditions prevailing in space and provide a comprehensive analytic characterization of its products. The application of 13C allowed us to confirm the suggested pathway of peptide formation that proceeds due to the polymerization of aminoketene molecules that are formed in the C + CO + NH3 reaction. Here, we address the question of how the efficiency of peptide production is modified by the presence of water molecules. We demonstrate that although water slightly reduces the efficiency of polymerization of aminoketene, it does not prevent the formation of peptides.


Assuntos
Meio Ambiente Extraterreno , Água , Meio Ambiente Extraterreno/química , Água/química , Peptídeos
12.
Wei Sheng Yan Jiu ; 53(2): 316-331, 2024 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-38604970

RESUMO

OBJECTIVE: To establishe an analysis and identification method for 2-methylisoborneol(2-MIB) and geosmin(GSM) in water using purge and trap-gas chromatography-mass spectrometry. METHODS: The samples were enriched and analyzed using a purge and trap system, followed by the separation on a DB-624(30 m×0.25 mm, 1.4 µm) chromatographic column. Quantification was performed using gas chromatography-mass spectrometry with the selected ion monitoring and internal standard calibration. RESULTS: The calibration curves for 2-MIB and GSM showed an excellent linearity in the range of 1 to 100 ng/L with R~2 values greater than 0.999. The detection limit and quantification limit for both 2-MIB and GSM were 0.33 ng/L and 1.0 ng/L, respectively. Spike recovery experiments were further carried on the source water and drinking water at three concentration levels. It showed that the average recoveries were from 82.0% to 111.0% for 2-MIB while 84.0% to 110% for GSM. Additionally, the test precision of 2-MIB and GSM ranged from 1.9% to 7.3% and 1.9% to 5.0%(n=6), respectively. The analysis of multiple samples including the local source water, treated water and distribution network water confirmed the existence of 2-MIB and GSM. CONCLUSION: Compared to the national standard(GB/T 5750.8-2023), the proposed method enables fully automated sample introduction and analysis without the extra pre-treatment. It provides the advantages of simplicity, good repeatability and high accuracy.


Assuntos
Água Potável , Naftóis , Poluentes Químicos da Água , Água/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Água Potável/análise , Canfanos/análise , Poluentes Químicos da Água/análise , Odorantes/análise
13.
Phys Chem Chem Phys ; 26(15): 11880-11892, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38568008

RESUMO

Recent experiments have revealed that adenosine triphosphate (ATP) suppresses the fibrillation of amyloid peptides - a process closely linked to neurodegenerative diseases such as Alzheimer's and Parkinson's. Apart from the adsorption of ATP onto amyloid peptides, the molecular understanding is still limited, leaving the underlying mechanism for the fibrillation suppression by ATP largely unclear, especially in regards to the molecular energetics. Here we provide an explanation at the molecular scale by quantifying the free energies using all-atom molecular dynamics simulations. We found that the changes of the free energies due to the addition of ATP lead to a significant equilibrium shift towards monomeric peptides in agreement with experiments. Despite ATP being a highly charged species, the decomposition of the free energies reveals that the van der Waals interactions with the peptide are decisive in determining the relative stabilization of the monomeric state. While the phosphate moiety exhibits strong electrostatic interactions, the compensation by the water solvent results in a minor, overall Coulomb contribution. Our quantitative analysis of the free energies identifies which intermolecular interactions are responsible for the suppression of the amyloid fibril formation by ATP and offers a promising method to analyze the roles of similarly complex cosolvents in aggregation processes.


Assuntos
Amiloide , Peptídeos , Amiloide/química , Peptídeos/química , Água/química , Entropia , Solventes/química , Simulação de Dinâmica Molecular , Proteínas Amiloidogênicas , Peptídeos beta-Amiloides/química , Fragmentos de Peptídeos/química
14.
Huan Jing Ke Xue ; 45(5): 2678-2685, 2024 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-38629531

RESUMO

Xingkai Lake, located in Heilongjiang Province, is an important fishery and agricultural base and is seriously polluted by agricultural non-point sources. To clarify the residual status of many pesticides in the surface water of Xingkai Lake, 27 types of pesticides, herbicides, and their degradation products were analyzed in rice paddy, drainage, and surface water around Xingkai Lake (China) during the rice heading and maturity periods. The results showed that all 27 types of pesticides, herbicides, and their degradation products were detected during the rice heading period, and the total concentration ranged from 247.97 to 6 094.49 ng·L-1. Additionally, 25 species were detected during the rice maturity period, and the total concentration ranged from 485.36 to 796.23 ng·L-1. In comparison, more pesticides, herbicides, and derived degradation products were detected during the heading period, and their total concentration was higher as well. During the rice heading period, atrazine, simetryn, and paclobutrazol were the main detected pesticides, atrazine and isoprothiolane were the main pesticides detected during the maturity period. The distribution characteristics of pesticides and herbicides in the surface water around Xingkai Lake (China) was similar to that in drainage, so they were probably imported from the drainage and rice paddy. The average risk quotient (RQ) values of atrazine, simetryn, prometryn, butachlor, isoprothiolane, and oxadiazon were higher than 0.1 in drainage and Xingkai Lake (China), which showed a potential risk to aquatic organisms.


Assuntos
Atrazina , Herbicidas , Resíduos de Praguicidas , Praguicidas , Tiofenos , Poluentes Químicos da Água , Praguicidas/análise , Resíduos de Praguicidas/análise , Lagos , Monitoramento Ambiental , Água/química , China , Medição de Risco , Poluentes Químicos da Água/análise
15.
Protein Sci ; 33(5): e4986, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38607226

RESUMO

Despite the generally accepted role of the hydrophobic effect as the driving force for folding, many intrinsically disordered proteins (IDPs), including those with hydrophobic content typical of foldable proteins, behave nearly as self-avoiding random walks (SARWs) under physiological conditions. Here, we tested how temperature and ionic conditions influence the dimensions of the N-terminal domain of pertactin (PNt), an IDP with an amino acid composition typical of folded proteins. While PNt contracts somewhat with temperature, it nevertheless remains expanded over 10-58°C, with a Flory exponent, ν, >0.50. Both low and high ionic strength also produce contraction in PNt, but this contraction is mitigated by reducing charge segregation. With 46% glycine and low hydrophobicity, the reduced form of snow flea anti-freeze protein (red-sfAFP) is unaffected by temperature and ionic strength and persists as a near-SARW, ν ~ 0.54, arguing that the thermal contraction of PNt is due to stronger interactions between hydrophobic side chains. Additionally, red-sfAFP is a proxy for the polypeptide backbone, which has been thought to collapse in water. Increasing the glycine segregation in red-sfAFP had minimal effect on ν. Water remained a good solvent even with 21 consecutive glycine residues (ν > 0.5), and red-sfAFP variants lacked stable backbone hydrogen bonds according to hydrogen exchange. Similarly, changing glycine segregation has little impact on ν in other glycine-rich proteins. These findings underscore the generality that many disordered states can be expanded and unstructured, and that the hydrophobic effect alone is insufficient to drive significant chain collapse for typical protein sequences.


Assuntos
Proteínas Intrinsicamente Desordenadas , Dobramento de Proteína , Água/química , Cloreto de Sódio , Glicina/química , Interações Hidrofóbicas e Hidrofílicas
16.
Chem Commun (Camb) ; 60(40): 5330-5333, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38666704

RESUMO

Single-cell nanoencapsulation (SCNE) has great potential in the enhancement of therapeutic effects of probiotic microbes. However, the material scope has been limited to water-soluble compounds to avoid non-biocompatible organic solvents that are harmful to living cells. In this work, the SCNE of probiotic Lactobacillus acidophilus with water-insoluble luteolin and Fe3+ ions is achieved by the vortex-assisted, biphasic water-oil system. The process creates L. acidophilus nanoencapsulated in the luteolin-Fe3+ shells that empower the cells with extrinsic properties, such as resistance to lysozyme attack, anti-ROS ability, and α-amylase-inhibition activity, as well as sustaining viability under acidic conditions. The proposed protocol, embracing water-insoluble flavonoids as shell components in SCNE, will be an advanced add-on to the chemical toolbox for the manipulation of living cells at the single-cell level.


Assuntos
Lactobacillus acidophilus , Luteolina , Óleos , Probióticos , Água , Lactobacillus acidophilus/metabolismo , Probióticos/química , Água/química , Luteolina/química , Óleos/química , alfa-Amilases/metabolismo
17.
Biomed Phys Eng Express ; 10(4)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38688251

RESUMO

Purpose.The aim of this study is to determine the planar dose distribution of irregularly-shaped electron beams at their maximum dose depth (zmax) using the modied lateral build-up ratio (LBR) and curve-fitting methods.Methods.Circular and irregular cutouts were created using Cerrobend alloy for a 14 × 14 cm2applicator. Percentage depth dose (PDD) at the standard source-surface-distance (SSD = 100 cm) and point dose at different SSD were measured for each cutout. Orthogonal profiles of the cutouts were measured atzmax. Data were collected for 6, 9, 12, and 15 MeV electron beam energies on a VERSA HDTMLINAC using the IBA Blue Phantom23D water phantom system. The planar dose distributions of the cutouts were also measured atzmaxin solid water using EDR2 films.Results.The measured PDD curves were normalized to a normalization depth (d0) of 1 mm. The lateral-buildup-ratio (LBR), lateral spread parameter (σR(z)), and effective SSD (SSDeff) for each cutout were calculated using the PDD of the open applicator as the reference field. The modified LBR method was then employed to calculate the planar dose distribution of the irregular cutouts within the field at least 5 mm from the edge. A simple curve-fitting model was developed based on the profile shapes of the circular cutouts around the field edge. This model was used to calculate the planar dose distribution of the irregular cutouts in the region from 3 mm outside to 5 mm inside the field edge. Finally, the calculated planar dose distribution was compared with the film measurement.Conclusions.The planar dose distribution of electron therapy for irregular cutouts atzmaxwas calculated using the improved LBR method and a simple curve-fitting model. The calculated profiles were within 3% of the measured values. The gamma passing rate with a 3%/3 mm and 10% dose threshold was more than 96%.


Assuntos
Elétrons , Imagens de Fantasmas , Dosagem Radioterapêutica , Elétrons/uso terapêutico , Humanos , Planejamento da Radioterapia Assistida por Computador/métodos , Algoritmos , Água/química , Método de Monte Carlo
18.
Environ Sci Pollut Res Int ; 31(21): 30663-30675, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38613752

RESUMO

In this study, dip coating method was investigated to prepare superhydrophilic MIL-101 (Cr)-coated copper mesh for highly efficient oil/water emulsion separation. To increase the surface area of synthesized MIL-101 (Cr), a purification procedure was developed to remove unreacted H2BDC crystals present in the channel of the initial MIL-101 (Cr) sample synthesized. After that, a dispersing solution of MIL-101 (Cr) was needed to coat on the copper mesh. Thermoplastic polyurethane (TPU) was used as a binder in this procedure. The prepared membranes of M1 (once coated mesh) to M6 (six times coated mesh) were performed to separate oil/water emulsion effectively. Contact angle tests showed the superhydrophilic/underwater superoleophobic wettability behavior of MIL-101 (Cr)-coated copper meshes. The wetting mechanism of the prepared membranes is mostly relevant to the surface functional groups of purified MIL-101 (Cr). Also, the roughness of the nanostructured coated membranes was improved because of the uniform coating of MIL-101 (Cr) which is integrated into hydrophilic TPU. Oil/water separation results showed that M2 (twice coated mesh) showed the maximum amount of water flux (83076 L m-2 h-1) in oil/water separation and M3 (three times coated mesh) had the best performance of oil/water emulsion with 99.99% separation efficiency.


Assuntos
Cobre , Emulsões , Interações Hidrofóbicas e Hidrofílicas , Estruturas Metalorgânicas , Água , Cobre/química , Estruturas Metalorgânicas/química , Água/química , Óleos/química , Molhabilidade
19.
J Ethnopharmacol ; 330: 118194, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-38641077

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Prinsepia utilis Royle, native to the Himalayan region, has a long history of use in traditional medicine for its heat-clearing, detoxification, anti-inflammatory, and analgesic properties. Oils extracted from P. utilis seeds are also used in cooking and cosmetics. With the increasing market demand, this extraction process generates substantial industrial biowastes. Recent studies have found many health benefits with using aqueous extracts of these biowastes, which are also rich in polysaccharides. However, there is limited research related to the reparative effects of the water extracts of P. utilis oil cakes (WEPUOC) on disruptions of the skin barrier function. AIM OF THE STUDY: This study aimed to evaluate the reparative efficacy of WEPUOC in both acute and chronic epidermal permeability barrier disruptions. Furthermore, the study sought to explore the underlying mechanisms involved in repairing the epidermal permeability barrier. MATERIALS AND METHODS: Mouse models with induced epidermal disruptions, employing tape-stripping (TS) and acetone wiping (AC) methods, were used. The subsequent application of WEPUOC (100 mg/mL) was evaluated through various assessments, with a focus on the upregulation of mRNA and protein expression of Corneocyte Envelope (CE) related proteins, lipid synthase-associated proteins, and tight junction proteins. RESULTS: The polysaccharide was the major phytochemicals of WEPUOC and its content was determined as 32.2% by the anthranone-sulfuric acid colorimetric method. WEPUOC significantly reduced transepidermal water loss (TEWL) and improved the damaged epidermal barrier in the model group. Mechanistically, these effects were associated with heightened expression levels of key proteins such as FLG (filaggrin), INV (involucrin), LOR (loricrin), SPT, FASN, HMGCR, Claudins-1, Claudins-5, and ZO-1. CONCLUSIONS: WEPUOC, obtained from the oil cakes of P. utilis, is rich in polysaccharides and exhibits pronounced efficacy in repairing disrupted epidermal barriers through increased expression of critical proteins involved in barrier integrity. Our findings underscore the potential of P. utilis wastes in developing natural cosmetic prototypes for the treatment of diseases characterized by damaged skin barriers, including atopic dermatitis and psoriasis.


Assuntos
Epiderme , Extratos Vegetais , Proteínas de Junções Íntimas , Regulação para Cima , Animais , Camundongos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Proteínas de Junções Íntimas/metabolismo , Epiderme/efeitos dos fármacos , Epiderme/metabolismo , Regulação para Cima/efeitos dos fármacos , Água/química , Óleos de Plantas/farmacologia , Óleos de Plantas/química , Masculino , Ácido Graxo Sintases/metabolismo , Ácido Graxo Sintases/genética , Permeabilidade/efeitos dos fármacos
20.
J Hazard Mater ; 471: 134364, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38657508

RESUMO

It is well known that arsenic is one of the most toxic elements. However, measuring total arsenic content is not enough, as it occurs in various forms that vary in toxicity. Since honey can be used as a bioindicator of environmental pollution, in the present study the concentration of arsenic and its species (As(III), As(V), DMA, MMA and AsB) was determined in honey samples from mostly Poland and Ukraine using HPLC-ICP-MS hyphenated technique. The accuracy of proposed methods of sample preparation and analysis was validated by analyzing certified reference materials. Arsenic concentration in honey samples ranged from 0.12 to 13 µg kg-1, with mean value of 2.3 µg kg-1. Inorganic arsenic forms, which are more toxic, dominated in honey samples, with Polish honey having the biggest mean percentage of inorganic arsenic species, and Ukrainian honey having the lowest. Furthermore, health risks resulting from the consumption of arsenic via honey were assessed. All Target Hazard Quotient (THQ) values, for total water-soluble arsenic and for each form, were below 1, and all Carcinogenic Risk (CR) values were below 10-4, which indicates no potential health risks associated with consumption of arsenic via honey at average or recommended levels.


Assuntos
Arsênio , Mel , Mel/análise , Cromatografia Líquida de Alta Pressão , Medição de Risco , Arsênio/análise , Espectrometria de Massas , Humanos , Contaminação de Alimentos/análise , Polônia , Solubilidade , Ucrânia , Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA