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1.
Eur Phys J E Soft Matter ; 47(6): 39, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831117

RESUMO

Small-Angle Scattering (SAS), encompassing both X-ray (SAXS) and Neutron (SANS) techniques, is a crucial tool for structural analysis at the nanoscale, particularly in the realm of biological macromolecules. This paper explores the intricacies of SAS, emphasizing its application in studying complex biological systems and the challenges associated with sample preparation and data analysis. We highlight the use of neutron-scattering properties of hydrogen isotopes and isotopic labeling in SANS for probing structures within multi-subunit complexes, employing techniques like contrast variation (CV) for detailed structural analysis. However, traditional SAS analysis methods, such as Guinier and Kratky plots, are limited by their partial use of available data and inability to operate without substantial a priori knowledge of the sample's chemical composition. To overcome these limitations, we introduce a novel approach integrating α -SAS, a computational method for simulating SANS with CV, with machine learning (ML). This approach enables the accurate prediction of scattering contrast in multicomponent macromolecular complexes, reducing the need for extensive sample preparation and computational resources. α -SAS, utilizing Monte Carlo methods, generates comprehensive datasets from which structural invariants can be extracted, enhancing our understanding of the macromolecular form factor in dilute systems. The paper demonstrates the effectiveness of this integrated approach through its application to two case studies: Janus particles, an artificial structure with a known SAS intensity and contrast, and a biological system involving RNA polymerase II in complex with Rtt103. These examples illustrate the method's capability to provide detailed structural insights, showcasing its potential as a powerful tool for advanced SAS analysis in structural biology.


Assuntos
Aprendizado de Máquina , Espalhamento a Baixo Ângulo , Substâncias Macromoleculares/química , Difração de Nêutrons , Difração de Raios X , Método de Monte Carlo
2.
Biochemistry (Mosc) ; 89(4): 747-764, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38831510

RESUMO

G protein-coupled receptors (GPCRs) play a key role in the transduction of extracellular signals to cells and regulation of many biological processes, which makes these membrane proteins one of the most important targets for pharmacological agents. A significant increase in the number of resolved atomic structures of GPCRs has opened the possibility of developing pharmaceuticals targeting these receptors via structure-based drug design (SBDD). SBDD employs information on the structure of receptor-ligand complexes to search for selective ligands without the need for an extensive high-throughput experimental ligand screening and can significantly expand the chemical space for ligand search. In this review, we describe the process of deciphering GPCR structures using X-ray diffraction analysis and cryoelectron microscopy as an important stage in the rational design of drugs targeting this receptor class. Our main goal was to present modern developments and key features of experimental methods used in SBDD of GPCR-targeting agents to a wide range of specialists.


Assuntos
Desenho de Fármacos , Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Humanos , Ligantes , Microscopia Crioeletrônica , Animais , Difração de Raios X
3.
BMC Oral Health ; 24(1): 650, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824555

RESUMO

BACKGROUND: The formation of white spots, which represent early carious lesions, is a major issue with fixed orthodontics. The addition of remineralizing agents to orthodontic adhesives may prevent the formation of white spots. The aim of this study was to produce a composite orthodontic adhesive combined with nano-bioactive glass-silver (nBG@Ag) for bracket bonding to enamel and to investigate its cytotoxicity, antimicrobial activity, remineralization capability, and bond strength. METHODS: nBG@Ag was synthesized using the sol-gel method, and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy with an attenuated total reflectance attachment (ATR-FTIR). The cytotoxicity test (MTT) and antimicrobial activity of adhesives containing 1%, 3%, and 5% (wt/wt) nBG@Ag were evaluated, and the shear bond strength of the adhesives was measured using a universal testing machine. Remineralization was assessed through microhardness testing with a Vickers microhardness tester and scanning electron microscopy (SEM). Statistical analyses were conducted using the Shapiro-Wilk test, Levene test, one-way ANOVA, Robust-Welch test, Tukey HSD method, and two-way ANOVA. RESULTS: The biocompatibility of the adhesives was found to be high, as confirmed by the lack of significant differences in the cytotoxicity between the sample and control groups. Discs made from composites containing nBG@Ag exhibited a significant reduction in the growth of Streptococcus mutans (p < 0.05), and the antibacterial activity increased with higher percentages of nBG@Ag. The shear bond strength of the adhesives decreased significantly (p < 0.001) after the addition of nanoparticles, but it remained above the recommended value. The addition of nBG@Ag showed improvement in the microhardness of the teeth, although the differences in microhardness between the study groups were not statistically significant. The formation of hydroxyapatite deposits on the tooth surface was confirmed through SEM and energy-dispersive X-ray spectroscopy (EDX). CONCLUSION: Adding nBG@Ag to orthodontic adhesives can be an effective approach to enhance antimicrobial activity and reduce enamel demineralization around the orthodontic brackets, without compromising biocompatibility and bond strength.


Assuntos
Antibacterianos , Cimentos Dentários , Braquetes Ortodônticos , Prata , Remineralização Dentária , Antibacterianos/farmacologia , Prata/farmacologia , Remineralização Dentária/métodos , Cimentos Dentários/farmacologia , Teste de Materiais , Nanoestruturas/uso terapêutico , Streptococcus mutans/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Vidro/química , Microscopia Eletrônica de Transmissão , Cerâmica , Humanos , Resinas Compostas/farmacologia , Resinas Compostas/química , Resistência ao Cisalhamento , Dureza , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos
4.
Food Res Int ; 189: 114561, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38876594

RESUMO

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.


Assuntos
Géis , Polissacarídeos , Reologia , Amido , Vigna , Amido/química , Polissacarídeos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Vigna/química , Difração de Raios X , Microscopia Eletrônica de Varredura , Interações Hidrofóbicas e Hidrofílicas , Água/química , Ligação de Hidrogênio
5.
Int J Nanomedicine ; 19: 5365-5380, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38859951

RESUMO

Background: Remineralization of dental enamel is an important intervention strategy for the treatment of demineralized lesions. Existing approaches have limitations such as failure to adequately reproduce both the ideal structural and mechanical properties of the native tooth. The ability of ultrasound to control and accelerate the crystallization processes has been widely reported. Therefore, a new approach was explored for in-vitro enamel remineralization involving the synergistic effect of high-intensity focused ultrasound (HIFU) coupled with calcium phosphate ion clusters (CPICs). Methods: The demineralized enamel was treated with CPICs, with or without subsequent HIFU exposure for different periods (2.5, 5, and 10 min). The specimens were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. The surface hardness and crystallographic properties of the treated specimens were evaluated using Vickers microhardness testing and X-ray diffraction (XRD), respectively. Results: SEM revealed distinct, organized, and well-defined prismatic structures, showing clear evidence of remineralization in the combined CPIC/HIFU treatment groups. AFM further revealed a decrease in the surface roughness values with increasing HIFU exposure time up to 5 min, reflecting the obliteration of interprismatic spaces created during demineralization. The characteristic Raman band at 960 cm-1 associated with the inorganic phase of enamel dominated well in the HIFU-treated specimens. Importantly, microhardness testing further demonstrated that new mineral growth also recovered the mechanical properties of the enamel in the HIFU-exposed groups. Critical to our aspirations for developing this into a clinical process, these results were achieved in only 5 min. Conclusion: HIFU exposure can synergise and significantly accelerate in-vitro enamel remineralization process via calcium phosphate ion clusters. Therefore, this synergistic approach has the potential for use in future clinical interventions.


Assuntos
Fosfatos de Cálcio , Esmalte Dentário , Microscopia de Força Atômica , Remineralização Dentária , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/química , Remineralização Dentária/métodos , Análise Espectral Raman , Microscopia Eletrônica de Varredura , Dureza , Propriedades de Superfície , Humanos , Desmineralização do Dente/terapia , Difração de Raios X , Animais , Bovinos
6.
AAPS PharmSciTech ; 25(5): 135, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862657

RESUMO

Lutein (Lut) is a recognized nutritional supplement known for its antioxidative and anti-inflammatory properties, crucial in mitigating ocular disease. However, enhancements to Lut stability and solubility remain challenges to be addressed in the healthcare industry. Herein, we fabricated and evaluated a food-grade highly porous ß-cyclodextrin metal-organic framework (ß-CD-MOF) for its ability to encapsulate Lut. Lut stability considerably improved when loaded into ß-CD-MOF to form a Lut@ß-CD-MOF complex, which exhibited better stability than Lut loaded into the γ-cyclodextrin metal-organic framework (Lut@γ-CD-MOF), Lut@ß-CD, and commercial product (Blackmores™) at 40°C, 60°C, and 70°C, respectively. The solubility of Lut@ß-CD-MOF in water increased by 26.8-fold compared to raw Lut at 37°C. Lut@ß-CD-MOF exhibited greater hydrophilicity, as determined by measuring the water contact angle. Molecular docking and other characterizations of Fourier transform infrared spectroscopy and powder X-ray diffraction confirmed that Lut was successfully encapsulated in the chamber formed by the three cyclodextrins in ß-CD-MOF. Thermogravimetric analysis and Raman spectroscopy demonstrated that Lut distributed in the ß-CD-MOF cavity deeply improved Lut stability and solubility. In conclusion, our findings underscored the function of ß-CD-MOF in enhancing Lut stability and solubility for formulation applications.


Assuntos
Luteína , Estruturas Metalorgânicas , Solubilidade , beta-Ciclodextrinas , Estruturas Metalorgânicas/química , beta-Ciclodextrinas/química , Luteína/química , Estabilidade de Medicamentos , Difração de Raios X/métodos , Simulação de Acoplamento Molecular/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Interações Hidrofóbicas e Hidrofílicas , Porosidade
7.
Adv Colloid Interface Sci ; 330: 103189, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38824717

RESUMO

Take your vitamins, or don't? Vitamin E is one of the few lipophilic vitamins in the human diet and is considered an essential nutrient. Over the years it has proven to be a powerful antioxidant and is commercially used as such, but this association is far from linear in physiology. It is increasingly more likely that vitamin E has multiple legitimate biological roles. Here, we review past and current work using neutron and X-ray scattering to elucidate the influence of vitamin E on key features of model membranes that can translate to the biological function(s) of vitamin E. Although progress is being made, the hundred year-old mystery remains unsolved.


Assuntos
Difração de Nêutrons , Vitamina E , Vitamina E/química , Humanos , Antioxidantes/química , Antioxidantes/farmacologia , Difração de Raios X
8.
Int J Biol Macromol ; 272(Pt 1): 132847, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38834115

RESUMO

This study explored the impact of sodium hydroxide and benzoylation treatment on the production of cellulose nanocrystals from Semantan bamboo (Gigantochloa scortechinii). Bamboo cellulose nanocrystals (BCNs) were obtained via acid hydrolysis, with the effectiveness of an isolation method and chemical treatments demonstrated in removing non-cellulosic constituents. X-ray diffraction analysis revealed a crystalline cellulose II structure for benzoylated BCN (B) and a crystalline cellulose I structure for NaOH-treated BCN (S), with BCN (S) exhibiting a higher crystallinity index (80.55 %) compared to BCN (B) (67.87 %). The yield of BCN (B) (23.68 ± 1.10 %) was higher than BCN (S) (20.65 ± 2.21 %). Transmission electron microscopy images showed a mean diameter of 7.95 ± 2.79 nm for BCN (S) and 9.22 ± 3.38 nm for BCN (B). Thermogravimetric analysis indicated lower thermal stability for BCN (B) compared to BCN (S), with charcoal residues at 600 °C of 31.06 % and 22 %, respectively. Zeta potential values were -41.60 ± 1.97 mV for BCN (S) and -21.80 ± 2.54 mV for BCN (B). Gigantochloa scortechinii holds significant potential for sustainable and eco-friendly applications in the construction, furniture, and renewable energy industries. These findings highlight the versatility and potential of BCNs derived from Gigantochloa scortechinii for various applications.


Assuntos
Celulose , Nanopartículas , Celulose/química , Nanopartículas/química , Poaceae/química , Hidrólise , Difração de Raios X
9.
AAPS PharmSciTech ; 25(5): 127, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844724

RESUMO

The success of obtaining solid dispersions for solubility improvement invariably depends on the miscibility of the drug and polymeric carriers. This study aimed to categorize and select polymeric carriers via the classical group contribution method using the multivariate analysis of the calculated solubility parameter of RX-HCl. The total, partial, and derivate parameters for RX-HCl were calculated. The data were compared with the results of excipients (N = 36), and a hierarchical clustering analysis was further performed. Solid dispersions of selected polymers in different drug loads were produced using solvent casting and characterized via X-ray diffraction, infrared spectroscopy and scanning electron microscopy. RX-HCl presented a Hansen solubility parameter (HSP) of 23.52 MPa1/2. The exploratory analysis of HSP and relative energy difference (RED) elicited a classification for miscible (n = 11), partially miscible (n = 15), and immiscible (n = 10) combinations. The experimental validation followed by a principal component regression exhibited a significant correlation between the crystallinity reduction and calculated parameters, whereas the spectroscopic evaluation highlighted the hydrogen-bonding contribution towards amorphization. The systematic approach presented a high discrimination ability, contributing to optimal excipient selection for the obtention of solid solutions of RX-HCl.


Assuntos
Química Farmacêutica , Excipientes , Polímeros , Cloridrato de Raloxifeno , Solubilidade , Difração de Raios X , Polímeros/química , Excipientes/química , Cloridrato de Raloxifeno/química , Análise Multivariada , Difração de Raios X/métodos , Química Farmacêutica/métodos , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Microscopia Eletrônica de Varredura/métodos , Ligação de Hidrogênio , Cristalização/métodos
10.
Sci Rep ; 14(1): 12818, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834602

RESUMO

Recent years have seen an increase in research on biodiesel, an environmentally benign and renewable fuel alternative for traditional fossil fuels. Biodiesel might become more cost-effective and competitive with diesel if a solid heterogeneous catalyst is used in its production. One way to make biodiesel more affordable and competitive with diesel is to employ a solid heterogeneous catalyst in its manufacturing. Based on X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FTIR), the researchers in this study proved their hypothesis that iron oxide core-shell nanoparticles were generated during the green synthesis of iron-based nanoparticles (FeNPs) from Camellia Sinensis leaves. The fabrication of spherical iron nanoparticles was successfully confirmed using scanning electron microscopy (SEM). As a heterogeneous catalyst, the synthesised catalyst has shown potential in facilitating the conversion of algae oil into biodiesel. With the optimal parameters (0.5 weight percent catalytic load, 1:6 oil-methanol ratio, 60 °C reaction temperature, and 1 h and 30 min reaction duration), a 93.33% yield was attained. This may be due to its acid-base property, chemical stability, stronger metal support interaction. Furthermore, the catalyst was employed for transesterification reactions five times after regeneration with n-hexane washing followed by calcination at 650 °C for 3 h.


Assuntos
Biocombustíveis , Camellia sinensis , Folhas de Planta , Folhas de Planta/química , Catálise , Camellia sinensis/química , Ferro/química , Nanopartículas Metálicas/química , Difração de Raios X , Esterificação , Espectroscopia de Infravermelho com Transformada de Fourier
11.
Microb Pathog ; 192: 106724, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38834135

RESUMO

Staphylococcus haemolyticus is a cause of bovine mastitis, leading to inflammation in the mammary gland. This bacterial infection adversely affects animal health, reducing milk quality and yield. Its emergence has been widely reported, representing a significant economic loss for dairy farms. Interestingly, S. haemolyticus exhibits higher levels of antimicrobial resistance than other coagulase-negative Staphylococci. In this study, we synthesized silver/silver chloride nanoparticles (Ag/AgCl-NPs) using Solanum lasiocarpum root extract and evaluated their antibacterial and antibiofilm activities against S. haemolyticus. The formation of the Ag/AgCl-NPs was confirmed using UV-visible spectroscopy, which revealed maximum absorption at 419 nm. X-ray diffraction (XRD) analysis demonstrated the crystalline nature of the Ag/AgCl-NPs, exhibiting a face-centered cubic lattice. Fourier transform infrared (FT-IR) spectroscopy elucidated the functional groups potentially involved in the Ag/AgCl-NPs synthesis. Transmission electron microscopy (TEM) analysis revealed that the average particle size of the Ag/AgCl-NPs was 10 nm. Antimicrobial activity results indicated that the minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) of the Ag/AgCl-NPs treatment were 7.82-15.63 µg/mL towards S. haemolyticus. Morphological changes in bacterial cells treated with the Ag/AgCl-NPs were observed under scanning electron microscopy (SEM). The Ag/AgCl-NPs reduced both the biomass of biofilm formation and preformed biofilm by approximately 20.24-94.66 % and 13.67-88.48 %. Bacterial viability within biofilm formation and preformed biofilm was reduced by approximately 21.56-77.54 % and 18.9-71.48 %, respectively. This study provides evidence of the potential of the synthesized Ag/AgCl-NPs as an antibacterial and antibiofilm agent against S. haemolyticus.


Assuntos
Antibacterianos , Biofilmes , Mastite Bovina , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Extratos Vegetais , Raízes de Plantas , Compostos de Prata , Prata , Solanum , Staphylococcus haemolyticus , Animais , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Antibacterianos/farmacologia , Antibacterianos/química , Prata/farmacologia , Prata/química , Biofilmes/efeitos dos fármacos , Compostos de Prata/farmacologia , Compostos de Prata/química , Bovinos , Mastite Bovina/microbiologia , Mastite Bovina/tratamento farmacológico , Raízes de Plantas/química , Nanopartículas Metálicas/química , Staphylococcus haemolyticus/efeitos dos fármacos , Feminino , Solanum/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Microscopia Eletrônica de Transmissão
12.
Clin Oral Investig ; 28(7): 370, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869624

RESUMO

OBJECTIVES: To investigate the effect of multiple firings on color, translucency, and biaxial flexure strength of Virgilite-containing (Li0.5Al0.5Si2.5O6) lithium disilicate glass ceramics of varying thickness. MATERIALS AND METHODS: Sixty discs were prepared from Virgilite-containing lithium disilicate blocks. Discs were divided according to thickness (n = 30) into T0.5 (0.5 mm) and T1.0 (1.0 mm). Each thickness was divided according to the number of firing cycles (n = 10); F1 (Control group): 1 firing cycle; F3: 3 firing cycles, and F5: 5 firing cycles. The discs were tested for color change (ΔE00) and translucency (TP00) using a spectrophotometer. Then, all samples were subjected to biaxial flexure strength testing using a universal testing machine. Data were collected and statistically analyzed (α = 0.5). For chemical analysis, six additional T0.5 discs (2 for each firing cycle) were prepared; for each firing cycle one disc was subjected to X-ray diffraction analysis (XRD) and another disc was subjected to Energy dispersive X-ray spectroscopy (EDX) and Scanning electron microscope (SEM). RESULTS: Repeated firing significantly reduced the translucency of F3 and F5 compared to F1 in T0.5 (p < 0.001), while for T1.0 only F5 showed a significant decrease in TP00 (p < 0.001). For ΔE00, a significant increase was recorded with repeated firings (p < 0.05) while a significant decrease resulted in the biaxial flexure strength regardless of thickness. CONCLUSIONS: Repeated firings had a negative effect on both the optical and mechanical properties of the Virgilite-containing lithium disilicate glass ceramics. CLINICAL RELEVANCE: Repeated firings should be avoided with Virgilite-containing lithium disilicate ceramics to decrease fracture liability and preserve restoration esthetics.


Assuntos
Cerâmica , Porcelana Dentária , Resistência à Flexão , Teste de Materiais , Propriedades de Superfície , Difração de Raios X , Cerâmica/química , Porcelana Dentária/química , Cor , Análise do Estresse Dentário , Espectrofotometria , Microscopia Eletrônica de Varredura , Temperatura Alta
13.
Lett Appl Microbiol ; 77(6)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38845375

RESUMO

This study explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using soil bacteria, Pseudomonas otitidis. The bio-synthesized AgNPs were characterized using various techniques, including UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). UV-visible spectroscopy revealed a distinct broad absorption band in the range of 443 nm, indicating the reduction of silver nitrate to AgNPs. XRD analysis provided evidence of the crystalline nature of the particles, with sharp peaks confirming their crystallinity and an average size of 82.76 nm. FTIR spectroscopy identified extracellular protein compounds as capping agents. SEM examination revealed spherical agglomeration of the crystalline AgNPs. The antimicrobial assay by a disc diffusion method, minimum inhibitory concentration, and minimum bactericidal concentration testing revealed that the biosynthesized AgNPs showed moderate antibacterial activity against both pathogenic Gram-negative (Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) and Gram-positive (Bacillus cereus, Staphylococcus aureus, and Streptococcus mutans) bacterial strains. Furthermore, the AgNPs significantly disrupted the biofilm of P. aeruginosa, as confirmed by crystal violet assay and fluorescent microscopy. Overall, this study underscores the potential of microbial-synthesized nanoparticles in biomedical applications, particularly in combating pathogenic bacteria, offering a promising avenue for future research and development.


Assuntos
Antibacterianos , Biofilmes , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Pseudomonas , Prata , Prata/farmacologia , Prata/química , Biofilmes/efeitos dos fármacos , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Antibacterianos/química , Pseudomonas/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Pseudomonas aeruginosa/efeitos dos fármacos
14.
J Mater Sci Mater Med ; 35(1): 30, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38884813

RESUMO

Pyrophyllite is the least studied natural clay in terms of its potential in biomedical applications, although there are many deposits of this aluminosilicate around the world. Genotoxicity study was performed in vitro for this mineral. Subsequently, Wister rats were exposed to the pyrophyllite micronized to below 100 µm. After the exposure period, histology of the lung, liver, kidney and gastric tissues were performed, followed by the stereological and hematological analysis. The physicochemical analyses revealed typical XRD characteristics of pyrophyllite clay with particle-size distribution ranging 50 nm-100 µm with stable mineral composition and unique buffering property to pH around 8. The results showed that there were no cytotoxic effects on to THP-1 cells, or genotoxicity of pyrophyllite measured by the Comet assay. In vivo studies are accompanied by the thorough physicochemical characterization of the micronized pyrophyllite. Histology of the lung tissue proved presence of an inflammatory reaction. On the other hand, gastric tissue has shown the selective accumulation of nanoparticles in enterocytes of the stomach only, as supported by ultrastructural analysis. Liver and kidney tissues have shown tolerability for pyrophyllite particles. The results give directions for further comprehensive studies of potential biomedical applications of the pyrophyllite.


Assuntos
Silicatos de Alumínio , Materiais Biocompatíveis , Rim , Fígado , Tamanho da Partícula , Ratos Wistar , Animais , Ratos , Materiais Biocompatíveis/química , Silicatos de Alumínio/química , Nanopartículas/química , Humanos , Teste de Materiais , Mucosa Gástrica/metabolismo , Masculino , Difração de Raios X , Ensaio Cometa , Argila/química
15.
PLoS One ; 19(6): e0304817, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38889131

RESUMO

Rice (Oryza sativa) stands as a crucial staple food worldwide, especially in Bangladesh, where it ranks as the third-largest producer. However, intensified cultivation has made high-yielding rice varieties susceptible to various biotic stresses, notably sheath blight caused by Rhizoctonia solani, which inflicts significant yield losses annually. Traditional fungicides, though effective, pose environmental and health risks. To address this, nanotechnology emerges as a promising avenue, leveraging the antimicrobial properties of nanoparticles like silver nanoparticles (AgNPs). This study explored the green synthesis of AgNPs using Ipomoea carnea leaf extract and silver nitrate (AgNO3), and also examined their efficacy against sheath blight disease in rice. The biosynthesized AgNPs were characterized through various analytical techniques such as UV-vis spectrophotometer, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Particle size analyzer, Zeta potential, Scanning Electron Microscope (SEM), Field Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscope (TEM) for confirming their successful production and crystalline nature of nanoparticles. The results of UV-visible spectrophotometers revealed an absorption peak ranging from 421 to 434 nm, validated the synthesis of AgNPs in the solution. XRD, DLS, and TEM estimated AgNPs sizes were ~45 nm, 66.2nm, and 46.38 to 73.81 nm, respectively. SEM and FESEM demonstrated that the synthesized AgNPs were spherical in shape. In vitro assays demonstrated the significant inhibitory effects of AgNPs on mycelial growth of Rhizoctonia solani, particularly at higher concentrations and pH levels. Further greenhouse and field experiments validated the antifungal efficacy of AgNPs against sheath blight disease in rice, exhibiting comparable effectiveness to commercial fungicides. The findings highlight the potential of AgNPs as a sustainable and effective alternative for managing rice sheath blight disease, offering a safer solution amidst environmental concerns associated with conventional fungicides.


Assuntos
Química Verde , Nanopartículas Metálicas , Oryza , Doenças das Plantas , Rhizoctonia , Prata , Rhizoctonia/efeitos dos fármacos , Oryza/microbiologia , Prata/química , Prata/farmacologia , Nanopartículas Metálicas/química , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Difração de Raios X , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Fungicidas Industriais/farmacologia , Fungicidas Industriais/química
16.
PLoS One ; 19(6): e0305761, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38889159

RESUMO

To explore the reaction mechanism of sludge, slag, lime, and fly ash in high temperature environments, the unconfined compressive strength (UCS) test was hereby implemented to study the effect on curing age, curing temperature, slag content and fly ash content about the strength of sludge. Scanning electron microscopy (SEM) was used to observe the microscopic composition of the substance, and X-ray diffraction (XRD) was used to analyze the mineral composition at the micro level to further disclose its reinforcement mechanism. The experimental results demonstrate the difference in the strength measured by different dosage of curing agent, and results indicate that the strength of high temperature curing sample was obviously higher than that of low temperature curing sample. When the curing temperature rises, the pozzolanic reaction and hydration reaction between materials are accelerated, and a certain amount of gel products are produced, playing a precipitation and bonding role between particles. The 28 days and 90 days strengths of the sludge samples with 20% fly ash and 80% slag dosing at 40°C were 1139 KPa and 1194 KPa, which were 1.4 and 1.1 times of that of pure cement solidified sludge. At 60°C, the strength of 14 days, 28 days and 90 days were 802 KPa, 1298 KPa and 1363 KPa, which were 1.1, 1.5 and 1.3 times of that of pure cement solidified sludge. Under the influence of an alkaline environment, the silicon-aluminum grid structure was interconnected into a denser network structure, and the compressive strength of lime-activated fly ash-slag was thus continuously enhanced. Affected by the high temperature, lime-activated fly ash-slag solidified sludge could significantly improve the middle and late strength of the sample. The research showed that the new solidification material can replace partly the concrete curing agent, thereby alleviating the carbon emission and environmental pollution problems arising from cement solidified sludge.


Assuntos
Compostos de Cálcio , Cinza de Carvão , Óxidos , Esgotos , Cinza de Carvão/química , Compostos de Cálcio/química , Esgotos/química , Óxidos/química , Temperatura Alta , Força Compressiva , Difração de Raios X , Microscopia Eletrônica de Varredura , Materiais de Construção/análise
17.
Sci Rep ; 14(1): 14015, 2024 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890382

RESUMO

Optimized production of Aspergillus niger ATCC 26011 endo-ß-mannanase (ManAn) on copra meal resulted in 2.46-fold increase (10,028 U/gds). Purified ManAn (47 kDa) showed high affinity towards guar gum (GG) as compared to konjac gum and locust bean gum with Km 2.67, 3.25 and 4.07 mg/mL, respectively. ManAn efficiently hydrolyzed GG and liberated mannooligosaccharides (MOS). Changes occurring in the rheological and compositional aspects of GG studied using Differential scanning calorimetry (DSC), Thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) revealed increased thermal stability and crystallinity of the partially hydrolyzed guar gum (PHGG). Parametric optimization of the time and temperature dependent hydrolysis of GG (1% w/v) with 100 U/mL of ManAn at 60 °C and pH: 5.0 resulted in 12.126 mg/mL of mannotetraose (M4) in 5 min. Enhanced growth of probiotics Lactobacilli and production of short chain fatty acids (SCFA) that inhibited enteropathogens, confirmed the prebiotic potential of PHGG and M4.


Assuntos
Aspergillus niger , Galactanos , Mananas , Oligossacarídeos , Gomas Vegetais , Prebióticos , beta-Manosidase , Mananas/química , Mananas/metabolismo , Gomas Vegetais/química , Galactanos/química , Aspergillus niger/enzimologia , Oligossacarídeos/química , Hidrólise , beta-Manosidase/metabolismo , beta-Manosidase/química , Concentração de Íons de Hidrogênio , Ácidos Graxos Voláteis/metabolismo , Difração de Raios X , Temperatura , Lactobacillus/metabolismo , Probióticos
18.
Int J Mol Sci ; 25(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38892315

RESUMO

The traditional production mode of the sericulture industry is no longer suitable for the development requirements of modern agriculture; to facilitate the sustainable development of the sericulture industry, factory all-age artificial diet feeding came into being. Understanding the structural characteristics and properties of silk fibers obtained from factory all-age artificial diet feeding is an important prerequisite for application in the fields of textiles, clothing, biomedicine, and others. However, there have been no reports so far. In this paper, by feeding silkworms with factory all-age artificial diets (AD group) and mulberry leaves (ML group), silk fibers were obtained via two different feeding methods. The structure, mechanical properties, hygroscopic properties, and degradation properties were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Structurally, no new functional groups appeared in the AD group. Compared with the ML group, the structure of the two groups was similar, and there was no significant difference in mechanical properties and moisture absorption. The structure of degummed silk fibers is dominated by crystalline regions, but α-chymotrypsin hydrolyzes the amorphous regions of silk proteins, so that after 28 d of degradation, the weight loss of both is very small. This provides further justification for the feasibility of factory all-age artificial diets for silkworms.


Assuntos
Bombyx , Seda , Animais , Seda/química , Bombyx/química , Difração de Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Morus/química
19.
Molecules ; 29(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38893457

RESUMO

The fibers from four wheat varieties (FT, XW 26, XW 45, and KW 1701) were selected and chemically modified with NaOH, epichlorohydrin, and dimethylamine to improve the adsorption capacity for anionic dye. The structure of the fibers with or without modification was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectrometry. The modified products were studied from the aspects of adsorption capacities, adsorption kinetics, and thermodynamics to provide a reference for the utilization of wheat bran. By SEM, more porous and irregular structures were found on the modified fibers. The XRD results showed that the crystals from the original fibers were destroyed in the modification process. The changes in fibers' infrared spectra before and after modification suggested that quaternary ammonium salts were probably formed in the modification process. The maximum adsorption capacity of wheat bran fibers for Congo red within 120 min was 20 mg/g for the unmodified fiber (XW 26) and 93.46 mg/g for the modified one (XW 45). The adsorption kinetics of Congo red by modified wheat bran fiber was in accord with the pseudo-second-order kinetic model at 40 °C, 50 °C, and 60 °C, indicating that the adsorption process might be mainly dominated by chemisorption. The adsorption was more consistent with the Langmuir isothermal adsorption model, implying that this process was monolayer adsorption. The thermodynamic parameters suggested that the adsorption occurred spontaneously, and the temperature increase was favorable to the adsorption. As mentioned above, this study proved that the wheat bran fiber could possess good adsorption capacities for anion dye after chemical modification.


Assuntos
Corantes , Fibras na Dieta , Termodinâmica , Adsorção , Fibras na Dieta/análise , Corantes/química , Cinética , Triticum/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Vermelho Congo/química
20.
Molecules ; 29(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38893470

RESUMO

With the global population on the rise, an escalating interest exists in environmentally sustainable and friendly protein sources. Insects have emerged as multifaceted resources, viewed not only as potential food items, but also as sources of traditional medicines and proteins. This study utilized response surface methodology (RSM) to ascertain the optimal extraction conditions for proteins from Musca domestica used in toad feeding, denoted as MDPs-T. The yield of MDPs-T was elevated to 18.3% ± 0.2% under these optimized conditions. Subsequently, the particle size, ζ-potentials, and structures of MDPs-T were analyzed and compared with the proteins derived from Musca domestica fed on a normal diet (MDPs-ND). This comparative analysis utilized a range of advanced techniques, involving UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high-performance gel permeation chromatography (HPGPC), and scanning electron microscopy (SEM). The outcomes have revealed a marginal disparity in the physical and chemical properties between MDPs-T and MDPs-ND. Derosination led to a reduction in the particle size of the MDPs by 10.98% to 62.81%. MDPs-T exhibited a higher proportion of low-molecular-weight components relative to MDPs-ND. Additionally, in a comparative analysis of amino acids, MDPs-T displayed a greater abundance of essential and total amino acids relative to MDPs-ND. Consequently, MDPs-T holds potential as a valuable food supplement for human consumption or as a nutrient-rich feed supplement for animals.


Assuntos
Moscas Domésticas , Proteínas de Insetos , Larva , Animais , Moscas Domésticas/química , Proteínas de Insetos/química , Proteínas de Insetos/isolamento & purificação , Larva/química , Espectroscopia de Infravermelho com Transformada de Fourier , Bufonidae , Difração de Raios X , Tamanho da Partícula , Ração Animal/análise
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