Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 181
Filtrar
1.
Anal Chem ; 96(1): 373-380, 2024 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-38113479

RESUMO

In this work, basic fuchsin (BF) dyestuff was presented as the first optical sensor used for the spectrofluorimetric assessment of morpholine (MOR) where BF exhibits morpholine-sensing behavior. The developed fluorimetric avenue is sensitive, facile, selective, and validated for assaying the sensitizing influence of MOR on the BF fluorescence in an aprotic dioxane solvent. Parameters like solvents, BF concentration, order, and time of addition that influence the fluorescence intensity of the probing system were addressed. Optimizing the analytical methodology revealed a linear fluorescence sensitization within the addition of MOR in the two concentration ranges of 5 × 10-9 to 1.0 × 10-7 mol L-1 and 2.0 × 10-7 to 3 × 10-6 mol L-1. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 2.0 × 10-9 mol L-1 (0.17 ng mL-1) and 6.66 × 10-9 mol L-1 (0.567 ng mL-1), respectively. High levels of accuracy and precision are achieved when assaying spiked MOR either in pure solutions or samples of fruit peel extract and human urine. Moreover, the green character and practicality/applicability of the method were evaluated by AGREE and BAGI metric tools. These merit outcomes provide insights into the development of fluorescent sensors for MOR detection using fluorescent dyes and meet the Food and Drug Administration's requirements for morpholine detection in real-life applications.


Assuntos
Corantes Fluorescentes , Frutas , Humanos , Preparações Farmacêuticas , Solventes , Espectrometria de Fluorescência/métodos , Morfolinas
2.
Environ Res ; 249: 118473, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38354892

RESUMO

The development of a catalyst with a consistent and clearly defined crystal structure is crucial for establishing an efficient catalytic performance system. This study focuses on catalyzing the reduction of nitroarenes to amino-derivatives in an aquatic environment at ambient temperature, employing metallic (Au) and bimetallic (Au-Pd or Au-Ag) nanoparticles loaded on a Ce-BTC metal-organic framework using a facile sol-immobilization approach. Diverse analytical instruments, comprising SEM, TEM, XRD, FT-IR, XPS, TGA, and N2 isotherm, have been utilized to characterize the synthesized catalysts. Among the catalysts that were fabricated, Au-Pd@Ce-BTC displayed the maximum catalytic efficacy, offering a rate constant (kapp) of 0.5841 min-1, conversion percentages reaching 99.7%, and a KAF of 116.8 min-1g-1. Moreover, it exhibited remarkable recyclability over five consecutive cycles. This catalyst offers the advantages of operating under ambient reaction conditions and exhibiting tolerance to a broad range of substrates containing various functional moieties. The mechanistic understanding of nitroarene reduction and the factors contributing to the superior activity of Au-Pd/Ce-BTC are explored through spectroscopic and porosity analyses. Spectroscopic measurements indicate that the elevated Auo and Pdo/Pd2+ ratio, increased surface area, and the synergistic collaboration of the bimetallic NPs are key factors contributing to the heightened activity of Au-Pd/Ce-BTC. These findings hold significant appeal from both an industrial and academic standpoint.


Assuntos
Nanopartículas Metálicas , Nanopartículas Metálicas/química , Catálise , Ouro/química , Estruturas Metalorgânicas/química , Oxirredução , Paládio/química , Cério/química , Poluentes Químicos da Água/química
3.
Environ Res ; 231(Pt 3): 116259, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37247654

RESUMO

We report a facile approach to synthesize Pd-Cu nanoparticles immobilized on a Noria-GO nanocomposite for efficient nitrophenol reduction. The unique architecture of the Noria and the hydrophilic nature of GO contribute to the improved performance and structure of the resulting nanocomposite. The simple sol-immobilization approach employed NaBH4 as a reductant and polyvinyl alcohol as a capping agent to evenly decorate small Pd-Cu nanoparticles with a diameter of 1.4 nm on the Noria-GO surface. The prepared Pd-Cu@Noria-GO nanocomposite was utilized as a nanocatalyst in converting of nitrophenol to aminophenol using NaBH4 solution. Our Pd-Cu@Noria-GO nanocomposite exhibited superior catalytic efficacy with large conversion percentages, Kapp, and KAF values of 95%, 0.225 min-1, and 225 min-1g-1, respectively. X-ray photoemission spectroscopy confirmed the oxidation state of the prepared nanoparticles, and TEM findings demonstrated the homogenous decoration of Pd-Cu NPs on the Noria-GO surface. Additionally, the durability of the Pd-Cu@Noria-GO nanocomposite shown its potential as a robust and promising material for remediating organic contaminants. Our results indicate that Pd-Cu@Noria-GO nanocomposite can be an effective and sustainable approach for mitigating the hazards associated with nitrophenols.


Assuntos
Nanocompostos , Nanopartículas , Nitrofenóis , Oxirredução , Nanocompostos/química , Substâncias Redutoras , Catálise
4.
Environ Res ; 234: 116587, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37423355

RESUMO

The outstanding properties of nanofiber composites have made them a popular choice for various structural applications. Recently, there has been a growing interest in using electrospun nanofibers as reinforcement agents, which possess exceptional properties that can enhance the performance of these composites. Herein, TiO2-graphene oxide (GO) nanocomposite incorporated into polyacrylonitrile (PAN)/cellulose acetate (CA) nanofibers were fabricated by an effortless electrospinning technique. The chemical and structural characteristics of the resulting electrospun TiO2-GO nanofibers were examined employing diverse techniques such as XRD, FTIR, XPS, TGA, mechanical properties, and FESEM. Remediation of organic contaminants and organic transformation reactions with electrospun TiO2-GO nanofibers were performed. The results indicated that the incorporation of TiO2-GO with various TiO2/GO ratios did not affect the molecular structure of PAN-CA. Still, they did significantly increase the mean fiber diameter (234-467 nm) and the mechanical properties of the nanofibers comprising UTS, elongation, Young's modulus, and toughness compared to PAN-CA. From various ratios of TiO2/GO (0.01TiO2/0.005GO and 0.005TiO2/0.01GO) in the electrospun NFs, the nanofiber containing a high content of TiO2 showed over 97% of the initial MB dyes were degraded after 120 min of visible light exposure and the same nanofibers also, achieved 96% nitrophenol conversion to aminophenol in just 10 min with activity factor kAF value of 47.7 g-1min-1. These findings illustrate the promise of TiO2-GO/PAN-CA nanofibers for use in various structural applications, particularly in the remediation of organic contaminants from water and organic transformation reactions.


Assuntos
Nanofibras , Nitrofenóis
5.
Microchem J ; 190: 108696, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37034437

RESUMO

Favipiravir (FVP) is introduced as a promising newly developed antiviral drug against the coronavirus disease 2019 (COVID-19). Therefore, the accurate determination of FVP is of great significance for quality assessment and clinical diagnosis. Herein, a novel electrochemical sensing platform for FVP based on gold nanoparticles anchored conductive carbon black (Au@CCB) modified graphite nanopowder flakes paste electrode (GNFPE) was constructed. Morphological and nanostructure properties of Au@CCB have been investigated by TEM, HRTEM, and EDX methods. The morphology and electrochemical properties of Au@CCB/GNFPE were characterized by SEM, cyclic voltammetry (CV), and EIS. The Au@CCB nanostructured modified GNFPE exhibited strong electro-catalytic ability towards the oxidation of FVP. The performance of the fabricated Au@CCB/GNFPE was examined by monitoring FVP concentrations in the absence and presence of co-administered drug paracetamol (PCT) by AdS-SWV. It was demonstrated that the proposed sensor exhibited superior sensitivity, stability, and anti-interference capability for the detection of FVP. The simultaneous determination of a binary mixture containing FVP and the co-administered drug PCT using Au@CCB/GNFPE sensor is reported for the first time. Under optimized conditions, the developed sensor exhibited sensitive voltammetric responses to FVP and PCT with low detection limits of 7.5 nM and 4.3 nM, respectively. The sensing electrode was successfully used to determine FVP and PCT simultaneously in spiked human plasma and pharmaceutical preparations, and the findings were satisfactory. Finally, the fabricated sensor exhibited high sensitivity for simultaneous detection of FVP and PCT in the presence of ascorbic acid in a real sample.

6.
Chem Biodivers ; 20(4): e202300152, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36914576

RESUMO

A new chelating task-specific ionic liquid (TSIL), lutidinium-based salicylaldoxime (LSOH), and its square pyramidal vanadyl(II) complex (VO(LSO)2 ) have been successfully synthesized and structurally characterized using elemental (CHN), spectral, and thermal analyses. The catalytic activity of the lutidinium-salicylaldoxime complex (VO(LSO)2 ) in the alkene epoxidation reactions was studied under various reaction conditions, such as solvent effect, alkene/oxidant molar ratio, pH, reaction temperature, reaction time, and the catalyst dose. The results demonstrated that the CHCl3 solvent, 1 : 3 of the cyclohexene/H2 O2 ratio, pH 8, temperature of 340 K, and catalyst dose of 0.012 mmol are assigned as the optimum conditions for achieving maximum catalytic activity for VO(LSO)2 . Moreover, the VO(LSO)2 complex has the potential for application in the effective and selective epoxidation of alkenes. Notably, under optimal VO(LSO)2 conditions, cyclic alkenes convert more efficiently to their corresponding epoxides than linear alkenes.


Assuntos
Compostos de Epóxi , Líquidos Iônicos , Alcenos , Catálise , Líquidos Iônicos/química , Oximas/química , Vanádio/química , Compostos de Epóxi/síntese química , Compostos de Epóxi/química
7.
J Environ Manage ; 332: 117351, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36731407

RESUMO

In this work, CdS quantum dots (QDs) were successfully confined in polysulfone membrane (PSM) to develop a photoactive membrane under solar illumination that was suited in wastewater remediating system. The CdS@PSM membranes were prepared using the nonsolvent induced phase separation (NIPS) approach. Optical measurements show the confinement of CdS quantum dots (QDs) in the PS matrix within the narrowest band gap (2.41 eV) at 5 wt% loading. PS has two strong emission peaks at 411 and 432 nm due to photoelectron-hole recombination on pure PSM's surface. Adding 1 wt% CdS QDs to PSM reduced the earlier peak and blue-shifted the latter, within the appearance of three emission peaks attributed to the near band-edge emission of confined CdS QDs. Overloading CdS reduced all emission peaks. Moreover, fluorimetric monitoring of •OH radicals indicates that PSM produces the least amount of photogenerated •OH radicals while CdS@PSM(5 wt%) achieved the highest productivity. Examining the developed membranes in detoxifying methylene blue (MB) from aqueous solution of natural pH 8.1 showed weak adsorption in dark over 90 min of contact while switching to solar illumination significantly photodegrade MB where the degradation efficiency starts from 49% for pure PSM to 79% for CdS@PSM(5 wt%). Influence of pH was found crucial on photodegradation efficacy. Acidic pH 3 showed the weakest photodegradation efficacy, while the alkaline pH 12 was 18.88 times more effective. The used CdS@PSM (5 wt%) was successfully photo-renovated by soaking in 10 mL of NaOH solution under Solar illumination for 15 min to be used in 4 consecutive photodegradation cycles with insignificant decrease in efficacy. These findings are promising and could lead to a high-efficiency, sustainable photocatalytic suite.


Assuntos
Pontos Quânticos , Águas Residuárias , Luz Solar , Polímeros
8.
Molecules ; 28(7)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37049835

RESUMO

Tailoring high-efficiency photocatalytic composites for various implementations is a major research topic. 1D TNTs-based nanomaterials show promise as a photocatalyst for the remediation of organic pigments in an aqueous solution. Despite this, TiO2 (TNTs) is only photoactive in the UV range due to its inherent restriction on absorption of light in the UV range. Herein, we provide a facile recipe to tailor the optical characteristics and photocatalytic activity of TNTs by incorporating Zn (II) ionic species via an ion-exchange approach in an aqueous solution. The inclusion of Zn (II) ions into the TNTs framework expands its absorption of light toward the visible light range, therefore TiO2 nanotubes shows the visible-light photo-performance. Activity performance on photocatalytic decontamination of RhB at ambient temperature demonstrates that Zn-TNTs offer considerable boosted catalytic performance compared with untreated tubular TiO2 during the illumination of visible light. RhB (10 mg L-1) degradation of around 95% was achieved at 120 min. Radical scavenger experiment demonstrated that when electron (e-) or holes (h+) scavengers are introduced to the photodegradation process, the assessment of decontamination efficacy decreased by 45% and 76%, respectively. This demonstrates a more efficient engagement of the photoexcited electrons over photogenerated holes in the photodegradation mechanism. Furthermore, there seems to be no significant decrease in the activity of the Zn-TNTs after five consecutive runs. As a result, the fabricated Zn-TNTs composite has a high economic potential in the energy and environmental domains.

9.
Molecules ; 27(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36364462

RESUMO

The arsenic (As) pollution of water has been eliminated via intensive scientific efforts, with the purpose of giving safe drinking water to millions of people across the world. In this study, the adsorption of As(V) from a synthetic aqueous solution was verified using a Bentonite-Anthracite@Zetag (BT-An@Zetag) composite. The SEM, FT-IR, XRD, DSC, TGA, and SBET techniques were used to characterize the (BT-An@Zetag) composite. The adsorption of As(V) was explored using batch adsorption under varied operating scenarios. Five kinetic modelswere used to investigate kinetic data, whereas three isotherms had been used to fit empirical equilibrium data. According to the findings, the adsorption mechanism of As(V) was best described by the Freundlich isotherm with a maximum monolayer coverage of 38.6 mg/g showing pseudo-second-order mode. The estimated enthalpy (H°) indicates that the adsorption process is both chemical and endothermic.The calculated free energy (G°) indicates that the reaction is nonspontaneous. After four sequential adsorption cycles, the produced BT-An@Zetag composite demonstrated good reusability and a greater adsorption affinity for As(V) ions. Overall, the BT-An@Zetag composite is suited for removing arsenic from wastewater using adsorption as a cost-effective and efficient technique.


Assuntos
Arsênio , Quitosana , Poluentes Químicos da Água , Humanos , Bentonita/química , Carvão Mineral , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/química , Quitosana/química , Adsorção , Água/química , Cinética , Termodinâmica , Concentração de Íons de Hidrogênio
10.
J Clin Monit Comput ; 35(5): 1069-1076, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32643129

RESUMO

In this study different mixtures from anesthetic liquids vapours in air and O2-sevoflurane/air, sevoflurane/O2 and isoflurane/O2-were prepared according to EN1839 method T. The gases mixtures were used to calibrate anesthetic gas monitors. The targeted concentrations (TCs) from sevoflurane and isoflurane in air and O2 were 0 vol%, 0.15 vol%, 0.7 vol%, 1 vol%, 1.5 vol%, 2.5 vol%, 5 vol%, 6 vol% and 8 vol%. The values of liquids, air and O2 flow rates which are corresponding theoretically to the TCs were calculated. The results showed that the measured concentrations by anesthetic gas monitor are in good agreement with TCs. Full validation was performed to assure the suitability of the method for preparing gas mixtures to calibrate anesthetic gas monitors. Linearity, limit of detection (LOD), limit of quantification (LOQ), precision, method robustness and uncertainty of measurement results were evaluated in the validation study. The results indicated that the method is valid for the purpose of analysis.


Assuntos
Anestésicos Inalatórios , Isoflurano , Calibragem , Gases , Humanos , Sevoflurano
11.
J Environ Manage ; 271: 110961, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778271

RESUMO

Herein, novel green/facile approach to synthesize spongy defective zinc oxide nanoparticles (ZnONPs) is presented using for the first time pomegranate seeds molasses as a green capping fuel/reducing mediator during an aqueous solution combustion process. The developed ZnONPs is characterized by UV-Vis. Spectrophotometry and fluorimetry, XRD, Raman spectroscopy, SEM, TEM and BET. Interestingly, pomegranate seeds molasses within a viable content of bio-capping molecules reveal a defective nanoporous ZnO NPs of smaller particle size, greater pore size/volume, and higher surface area compared to the bulky non-biogenic ZnONPs. Moreover, the biosynthesized defective ZnONPs showed narrowed band gap and higher absorption of visible photons that breed higher density of hydroxyl radicals (•OH) under Solar-illumination. Even further, the bulk ZnO and the biosynthesized ZnO photocatalysts were examined in photodegrading flumequine (FL) antibiotic. The bulk ZnO gives 41.46% photodegradation efficiency compared to 97.6% for the biosynthesized ZnO. In highly acidic or highly alkaline media, FL photodegradability is greatly retarded. Scavenging experiment infers considerable contribution of holes over electrons in photodegradation reaction. The biosynthesized ZnO shows high durability in FL photodegradation after four reusing cycles. These promising findings highlight new insights for biogenic synthesis of tuned size/controlled morphology semiconductor NPs relevant to environmental remediation applications.


Assuntos
Óxido de Zinco , Antibacterianos , Radical Hidroxila , Extratos Vegetais , Águas Residuárias
12.
Measurement (Lond) ; 149: 106804, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32287815

RESUMO

The paper presents a feasibility study for heart rate measurement using a digital camera to perform health monitoring. The feasibility study investigates the reliability of the state of the art heart rate measuring methods in realistic situations. Therefore, an experiment was designed and carried out on 45 subjects to investigate the effects caused by illumination, motion, skin tone, and distance variance. The experiment was conducted for two main scenarios; human-computer interaction scenario and health monitoring scenario. The human-computer scenario investigated the effects caused by illumination variance, motion variance, and skin tone variance. The health monitoring scenario investigates the feasibility of health monitoring at public spaces (i.e. airports, subways, malls). Five state of the art heart rate measuring methods were re-implemented and tested with the feasibility study database. The results were compared with ground truth to estimate the heart rate measurement error. The heart rate measurement error was analyzed using mean error, standard deviation; root means square error and Pearson correlation coefficient. The findings of this experiment inferred promising results for health monitoring of subjects standing at a distance of 500 cm.

13.
Microb Pathog ; 107: 29-37, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28315387

RESUMO

Avian pathogenic Escherichia coli is an important pathogen causes systemic infections in avian species and large economic losses in poultry industry worldwide. The functional role of porins during the infection and their mechanisms of interaction with host tissues for adhesion to and invasion are poorly understood. However, whether porins play a role in infection remains unclear. In this study we evaluated the potential of ompF and ompC outer membrane porins in the pathogenesis of avian pathogenic E. coli (APEC) strain TW-XM. The ompF and ompC were deleted to generate a series of mutants. We found that, ΔompF and ΔompC reduced significantly the adherence by 41.3% and 46.1% and invasion capabilities of APEC to mouse brain microvascular endothelial cell (BMEC) bEnd.3 cells in vitro by 51.9% and 49.7% respectively, compared with the wild strain TW-XM. In vivo experiment based on the measurement of the LD50 have also shown that, ΔompF and ΔompC reduced the bacterial virulence by 9.8-fold, 12.3-fold in ducklings and 9-fold, 10.2-fold in mouse models. Animal infection experiments further revealed that, loss of ompF and ompC reduced TW-XM colonization and invasion capacity in brains, lungs and blood compared to wild-type strain TW-XM (P > 0.01). These virulence-related phenotypes were partially recoverable by genetic complementation. The results of the quantitative real-time reverse transcription-PCR (qRT-PCR) indicated that, the loss of ompF and ompC significantly decreased the expression levels of ompA, fimC and iBeA genes in the mutant strains, compared to wild-type strainTW-XM (P < 0.01). Collectively, our data demonstrate that inactivation of these two porins decreased adhesion, invasion, colonization, proliferation capacities, possibly by reduced expression levels of ompA, fimC and iBeA, which may indicate the involvement of ompF and ompC in APEC pathogenesis.


Assuntos
Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Porinas/fisiologia , Doenças das Aves Domésticas/microbiologia , Virulência/genética , Virulência/fisiologia , Animais , Anticorpos Antibacterianos , Aderência Bacteriana/genética , Aderência Bacteriana/fisiologia , Proteínas da Membrana Bacteriana Externa/biossíntese , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas da Membrana Bacteriana Externa/fisiologia , Aves , Encéfalo/microbiologia , Linhagem Celular/microbiologia , Contagem de Colônia Microbiana , DNA Bacteriano/genética , Modelos Animais de Doenças , Patos/microbiologia , Células Endoteliais/microbiologia , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/fisiologia , Proteínas de Fímbrias/biossíntese , Proteínas de Fímbrias/genética , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Dose Letal Mediana , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Camundongos , Porinas/genética , Porinas/metabolismo , Coelhos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Proteínas Recombinantes/genética , Análise de Sequência , Deleção de Sequência , Análise de Sobrevida
14.
BMC Vet Res ; 13(1): 94, 2017 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-28388949

RESUMO

BACKGROUND: Swine extraintestinal pathogenic Escherichia coli (ExPEC) is an important pathogen that leads to economic and welfare costs in the swine industry worldwide, and is occurring with increasing frequency in China. By far, various virulence factors have been recognized in ExPEC. Here, we investigated the virulence genotypes and clonal structure of collected strains to improve the knowledge of phylogenetic traits of porcine ExPECs in China. RESULTS: We isolated 64 Chinese porcine ExPEC strains from 2013 to 14 in China. By multiplex PCR, the distribution of isolates belonging to phylogenetic groups B1, B2, A and D was 9.4%, 10.9%, 57.8% and 21.9%, respectively. Nineteen virulence-related genes were detected by PCR assay; ompA, fimH, vat, traT and iutA were highly prevalent. Virulence-related genes were remarkably more prevalent in group B2 than in groups A, B1 and D; notably, usp, cnf1, hlyD, papA and ibeA were only found in group B2 strains. Genotyping analysis was performed and four clusters of strains (named I to IV) were identified. Cluster IV contained all isolates from group B2 and Cluster IV isolates had the strongest pathogenicity in a mouse infection model. As phylogenetic group B2 and D ExPEC isolates are generally considered virulent, multilocus sequence typing (MLST) analysis was performed for these isolates to further investigate genetic relationships. Two novel sequence types, ST5170 and ST5171, were discovered. Among the nine clonal complexes identified among our group B2 and D isolates, CC12 and CC95 have been indicated to have high zoonotic pathogenicity. The distinction between group B2 and non-B2 isolates in virulence and genotype accorded with MLST analysis. CONCLUSION: This study reveals significant genetic diversity among ExPEC isolates and helps us to better understand their pathogenesis. Importantly, our data suggest group B2 (Cluster IV) strains have the highest risk of causing animal disease and illustrate the correlation between genotype and virulence.


Assuntos
Infecções por Escherichia coli/veterinária , Escherichia coli Extraintestinal Patogênica/genética , Escherichia coli Extraintestinal Patogênica/patogenicidade , Doenças dos Suínos/microbiologia , Animais , China/epidemiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli Extraintestinal Patogênica/classificação , Variação Genética , Camundongos , Tipagem de Sequências Multilocus , Filogenia , Suínos/microbiologia , Doenças dos Suínos/epidemiologia , Virulência , Fatores de Virulência/genética
15.
Eur J Clin Microbiol Infect Dis ; 34(12): 2447-53, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26440040

RESUMO

Cryptosporidiosis is a worldwide gastrointestinal disease caused by the protozoan Cryptosporidium parasite. It has a broad range of seasonal and age-related prevalence. We aimed to study the molecular prevalence and seasonality of Cryptosporidium over a period of 1 year in a cohort of Egyptian diarrhoeic patients. Stool samples were collected from 865 diarrhoeic patients attending outpatient clinics of Cairo University hospitals, from all age groups over a 12-month period, examined microscopically for faecal Cryptosporidium oocysts by the acid-fast staining method and for copro-DNA detection using nested polymerase chain reaction (nPCR) assays. PCR-positive samples were characterised molecularly by nPCR-restriction fragment length polymorphism (RFLP) to determine Cryptosporidium genotypes. Cryptosporidium copro-DNA was detected in 19.5% of the collected samples throughout the year, with a major peak in summer (August) and a small rise in spring (April). Infection was mainly C. hominis (95.8%) followed by C. parvum (3.0%), affecting all age groups, with predominance in the pre-school age group, and decrease with age. There were statistically significant associations between the detection of Cryptosporidium and season, diarrhoea, patient age and drinking water, while gender, contact with animals and presence of mucus in stool showed no association. Cryptosporidium in diarrhoeic Egyptians was of distinct endemicity, with the bi-model mostly influenced by population dynamics, with a clear high prevalence in pre-school children and predominating anthroponotic (C. hominis) transmission throughout the year. The obtained results highlight Cryptosporidium as a water contaminant and an important cause of health problems in Egypt, necessitating further studies of the risk factors.


Assuntos
Criptosporidiose/epidemiologia , Cryptosporidium/classificação , Cryptosporidium/genética , Diarreia/epidemiologia , Doenças Endêmicas , Genótipo , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Técnicas de Laboratório Clínico , Estudos Transversais , Criptosporidiose/parasitologia , Cryptosporidium/isolamento & purificação , Diarreia/parasitologia , Egito/epidemiologia , Fezes/parasitologia , Feminino , Hospitais Universitários , Humanos , Lactente , Recém-Nascido , Técnicas de Diagnóstico Molecular , Pacientes Ambulatoriais , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prevalência , Fatores de Risco , Estações do Ano , Fatores Sexuais , Adulto Jovem
16.
Dis Esophagus ; 28(5): 422-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24708423

RESUMO

Caustic ingestion in children and the resulting long esophageal strictures are usually difficult to be managed, and eventually, esophageal replacement was required for cases refractory to frequent dilatation sessions. Topical mitomycin C (MMC) application has been used recently to improve the results of endoscopic dilatation for short esophageal strictures. The study aims to assess the role of MMC application in management of long-segment caustic esophageal strictures. From January 2009 to June December 2013, patients presented with long caustic esophageal stricture (>3 cm in length) were included in this study and subjected to topical MMC application after endoscopic esophageal dilatation on multiple sessions. Regular follow-up and re-evaluation were done. A dysphagia score was used for close follow-up clinically; verification was done radiologically and endoscopically. During the specified follow-up period, 21 patients with long caustic esophageal stricture were subjected to topical MMC application sessions. Clinical, radiological, and endoscopic resolution of strictures occurred in 18 patients (85.7% cure rate). Number of dilatation sessions to achieve resolution of dysphagia was (n = 14.3 ± 5.7) with application of mitomycin two to six times. There was no recurrence in short- and mid-term follow-up. No complications were encountered related to topical MMC application. MMC is a promising agent in management of long-segment caustic esophageal strictures. Long-term follow-up is needed to prove its efficacy and to evaluate potential long-term side-effects of MMC application.


Assuntos
Alquilantes/administração & dosagem , Queimaduras Químicas/complicações , Transtornos de Deglutição/tratamento farmacológico , Estenose Esofágica/complicações , Mitomicina/administração & dosagem , Administração Tópica , Cáusticos/toxicidade , Pré-Escolar , Transtornos de Deglutição/etiologia , Dilatação , Método Duplo-Cego , Estenose Esofágica/induzido quimicamente , Estenose Esofágica/terapia , Esofagoscopia , Feminino , Humanos , Lactente , Masculino , Resultado do Tratamento
17.
East Mediterr Health J ; 20(12): 765-73, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25664514

RESUMO

Tobacco smoking is an emerging problem among adolescents in the United Arab Emirates (UAE). This study aimed to measure the prevalence of current tobacco use and its associated factors among school students in Dubai Emirate and to determine the impact of an intervention programme on knowledge and attitudes towards tobacco use. A school-based intervention programme was carried out among 2457 students aged 10-20 years and data were collected with a self-administered questionnaire. Of the students, 14.6% were tobacco users, mostly cigarettes (11.2%) and waterpipes (2.2%). The most common self-reported reasons for smoking were for the experience (29.4%), for stress relief (22.5%) and because their peers smoked (21.9%). Stepwise logistic regression analysis showed that the predictors of tobacco use were: male, higher age, UAE national, higher school level, government school, low knowledge about tobacco and family history of smoking. There were significant improvements in knowledge and attitudes scores after the health education intervention programme.


Assuntos
Educação em Saúde , Fumar/epidemiologia , Tabaco sem Fumaça/estatística & dados numéricos , Adolescente , Criança , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Promoção da Saúde , Humanos , Masculino , Prevenção do Hábito de Fumar , Estudantes , Inquéritos e Questionários , Emirados Árabes Unidos/epidemiologia
18.
Int J Biol Macromol ; 270(Pt 2): 132252, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729503

RESUMO

In this study, we developed a novel nanocomposite by synthesizing zinc (ZnNPs), copper (CuNPs), and silver (AgNPs) nanoparticles using olive leaf extract and incorporating them into a chitosan polymer. This approach combines the biocompatibility of chitosan with the antimicrobial and anticancer properties of metal nanoparticles, enhanced by the phytochemical richness of olive leaf extract. The significance of our research lies in its potential to offer a biodegradable and stable alternative to conventional antibiotics and cancer treatments, particularly in combating multidrug-resistant bacteria and various cancer types. Comprehensive characterization through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Transmission Electron Microscopy (TEM) confirmed the successful synthesis of the nanocomposites, with an average size of ~22.6 nm. Phytochemical analysis highlighted the antioxidant-rich composition of both the olive leaf extract and the nanoparticles themselves. Functionally, the synthesized nanoparticles exhibited potent antimicrobial activity against multidrug-resistant bacterial strains, outperforming traditional antibiotics by inhibiting key resistance genes (ermC, tetX3-q, blaZ, and Ery-msrA). In anticancer assessments, the nanoparticles showed selective cytotoxicity towards cancer cells in a concentration-dependent manner, with CuNPs and AgNPs showing particularly strong anticancer effects, while demonstrating minimal toxicity towards normal cells. ZnNPs were noted for their low cytotoxicity, highlighting the safety profile of these nanoparticles. Further, the nanoparticles induced apoptosis in cancer cells, as evidenced by the modulation of oncogenes (P21, P53, and BCL2), suggesting their therapeutic potential. The findings of our study underscore the versatile applications of these biogenic nanoparticles in developing safer and more effective antimicrobial and anticancer therapies.


Assuntos
Antineoplásicos , Quitosana , Química Verde , Nanopartículas Metálicas , Nanocompostos , Olea , Extratos Vegetais , Folhas de Planta , Quitosana/química , Quitosana/farmacologia , Nanocompostos/química , Olea/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Humanos , Folhas de Planta/química , Nanopartículas Metálicas/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/síntese química , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Prata/química , Prata/farmacologia , Linhagem Celular Tumoral
19.
Pathol Biol (Paris) ; 61(6): 250-3, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23751360

RESUMO

The aim of this study was designed to evaluate the possible protective effects of Nigella sativa (NS) on the neuronal injury in the sciatic nerve of rats. The rats were randomly allotted into one of the three experimental groups: A (control), B (only trauma) and C (trauma and treated with NS); each group contain 10 animals. Sciatic nerve injury was performed by placing an aneurysm clip on the left leg. Rats were neurologically tested over 24h after trauma. The rats in NS-treated group was given NS (in a dose of 400mg/kg body weight) once a day orally for 30 days starting just after trauma. Control and untreated (only trauma) rats were injected with the same volume of isotonic NaCl as the treated animals that received NS. Tissue samples were obtained for histopathological investigation. To date, no histopathological changes of neurodegeneration in the sciatic nerve after trauma in rats by NS treatment have been reported. Results showed in the group B (only trauma), the neurons of sciatic nerve tissue became extensively dark and degenerated with picnotic nuclei. Treatment of NS markedly reduced degenerating neurons after trauma and the distorted nerve cells were mainly absent in the NS-treated rats. The morphology of neurons in groups treated with NS was well protected, but not as neurons of the control group. The number of neurons in sciatic nerve tissue of group B (only trauma) was significantly less than both control and treated with NS groups. The morphology of neurons revealed that the number of neurons were significantly less in group B compared to control (P<0.001) and group C (P<0.01) rats' motor neurons anterior horn spinal cord tissue. We conclude that NS therapy causes morphologic improvement on neurodegeneration in sciatic nerve after trauma in rats.


Assuntos
Neurônios Motores/efeitos dos fármacos , Fármacos Neuroprotetores , Nigella sativa , Extratos Vegetais , Nervo Isquiático/lesões , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Contagem de Células , Masculino , Neurônios Motores/patologia , Neurônios Motores/fisiologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Nigella sativa/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos , Ratos Wistar , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/patologia , Nervo Isquiático/fisiologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Medula Espinal/fisiologia , Traumatismos da Medula Espinal/patologia
20.
Front Physiol ; 14: 1168284, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37362433

RESUMO

Characterization and functional profiling of the gut microbiota are essential for guiding nutritional interventions in fish and achieving favorable host-microbe interactions. Thus, we conducted a 30 days study to explore and document the gut microbial community of O. niloticus, as well as to evaluate the effects of a polysaccharide-based prebiotics with 0.5% and 0.75% Aloe vera extract on the gut microbiome through genomic analysis. The V3-V4 region of 16S rRNA was amplified and sequenced using Illumina HiSeq 2500, resulting in 1,000,199 reads for operational taxonomic unit (OTU) identification. Out of 8,894 OTUs, 1,181 were selected for further analysis. Our results revealed that Planctomycetes, Firmicutes, Proteobacteria, Verrucomicrobia, Actinobacteria, and Fusobacteria were the dominant phyla in both control and treatment samples. Higher doses of prebiotics were found to improve Planctomycetes and Firmicutes while decreasing Proteobacteria and Verrucomicrobia. We observed increasing trends in the abundance of Bacilli, Bacillaceae, and Bacillus bacteria at the class, family, and genus levels, respectively, in a dose-dependent manner. These findings were consistent with the conventional colony count data, which showed a higher prevalence of Bacillus in prebiotic-supplemented groups. Moreover, predicted functional analysis using PICRUSt indicated a dose-dependent upregulation in glycolysis V, superpathway of glycol metabolism and degradation, glucose and xylose degradation, glycolysis II, and sulfoglycolysis pathways. Most of the energy, protein, and amino acid synthesis pathways were upregulated only at lower doses of prebiotic treatment. Our findings suggest that the gut microbiome of O. niloticus can be optimized through nutritional interventions with plant-based polysaccharides for improved growth performance in commercial fish.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa