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AIMS AND BACKGROUND: To assess the procedural errors committed by undergraduate students at RAK College of Dental Sciences, during root canal treatments and the factors associated with these errors. MATERIALS AND METHODS: In this cross-sectional study, 180 self-administered questionnaires were distributed, each comprising 26 questions, among 4th and 5th-year students. Participants were requested to report their endodontic mishaps based on feedback from their supervisors. The questionnaire assessed the frequency and types of procedural errors, considering patient, operator, and tooth-related factors. Data were collected tabulated and analyzed using the Chi-square test. RESULTS: A total of 124 root canal-treated teeth exhibiting iatrogenic errors done by students were assessed. Out of which, 53% were performed by 5th-year students, and 69% were conducted by female operators. About 62% of errors occurred in the upper teeth and 68% in the posterior teeth. The most prevalent errors during the rubber dam isolation step were soft tissue trauma (21%) and isolation leakage (20%), significantly associated with limited mouth opening, excessive salivation, and tooth malalignment (p < 0.05). Apical blockage (15%) emerged as the most frequent error during instrumentation phase, showing a significant association with canal dimension and curvature (p < 0.05). For access cavity and obturation phases, under-extended cavity (9%), and under-extended filling (11%) were the most reported errors, respectively. CONCLUSION: Tooth isolation emerges as a particularly challenging aspect for dental students, particularly when dealing with patients exhibiting limited mouth opening and excessive salivation. CLINICAL SIGNIFICANCE: Clinical instructors should caution the undergraduates about the heightened risk of endodontic procedural errors when dealing with patients exhibiting limited mouth opening, excessive salivation, tooth misalignment, and narrow canals. Addressing these challenges is crucial for enhancing the proficiency of undergraduate students in performing successful root canal treatments. How to cite this article: Elsayed MA, Islam MS, Saleh DR, et al. Endodontic Procedural Errors and Associated Factors among Undergraduate Dental Students: A Cross-sectional Study. J Contemp Dent Pract 2023;24(12):998-1007.
Assuntos
Tratamento do Canal Radicular , Estudantes de Odontologia , Humanos , Feminino , Estudos Transversais , Tratamento do Canal Radicular/métodos , Distribuição de Qui-Quadrado , Cabeça , Cavidade PulparRESUMO
Magnesium ferrite nanoparticles (Mg Fe2O4 NPs) was synthesized by a chemical co-precipitation method and characterized via structural and optical properties. The surface of Mg Fe2O4 NPs was stabilized with citric acid (CA) by a direct addition method (CA-Mg Fe2O4 NPs), then Amoxicillin (AX) was loaded with CA-Mg Fe2O4 nanocomposites. Furthermore, their antimicrobial, and antibiofilm activities, growth curve, and effect of UV-illumination methods were examined against different pathogenic microbes. Based on XRD, HRTEM and SEM analyses, it is found that Mg Fe2O4 NPs are located at the core, while the CA and AX are coated this core. In-vitro zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) results verified that AX-loaded CA-Mg Fe2O4 nanocomposites exhibited its encouraged antimicrobial activity against S. aureus, E. coli, and C. albicans (32.2, 22.0, and 19.0 mm ZOI, respectively) & (0.312, 0.625, and 1.25 µg/ml MIC, respectively). AX-CA-Mg Fe2O4 nanocomposites are showed antibiofilm percentage against S. aureus (95.34%), E. coli (93.93%), and C. albicans (76.23%). AX-CA-MgFe2O4 nanocomposites are an excellent disinfectant agents once they are excited by UV light. Membrane leakage assay explains the formation of holes on the surface of bacteria, and confirms SEM reaction mechanism. AX-loaded CA-Mg Fe2O4 NPs are promising for potential applications in biomedical uses.
Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Nanocompostos , Amoxicilina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Biofilmes , Ácido Cítrico/farmacologia , Escherichia coli , Compostos Férricos , Iluminação , Compostos de Magnésio , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Nanocompostos/química , Staphylococcus aureus , Raios UltravioletaRESUMO
Global warming and climate change adversely affect livestock and poultry production sectors under tropical and subtropical conditions. Heat stress is amongst the most significant stressors influencing poultry productivity in hot climate regions, causing substantial economic losses in poultry industry. These economic losses are speculated to increase in the coming years with the rise of global temperature. Moreover, modern poultry strains are more susceptible to high ambient temperature. Heat stress has negative effects on physiological response, growth performance and laying performance, which appeared in the form of reducing feed consumption, body weight gain, egg production, feed efficiency, meat quality, egg quality and immune response. Numerous practical procedures were used to ameliorate the negative impacts of increased temperature; among them the dietary manipulation, which gains a great concern in different regions around the world. These nutritional manipulations are feed additives (natural antioxidants, minerals, electrolytes, phytobiotics, probiotics, fat, and protein), feed restriction, feed form, drinking cold water and others. However, in the large scale of poultry industry, only a few of these strategies are commonly used. The current review article deliberates the different practical applications of useful nutritional manipulations to mitigate the heat load in poultry. The documented information will be useful to poultry producers to improve the general health status and productivity of heat-stressed birds via enhancing stress tolerance, oxidative status and immune response, and thereby provide recommendations to minimize production losses due to heat stress in particular under the growing global warming crisis.
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Dieta/veterinária , Transtornos de Estresse por Calor/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Animais , Ingestão de Líquidos , Microbioma Gastrointestinal , Transtornos de Estresse por Calor/metabolismo , Transtornos de Estresse por Calor/microbiologia , Resposta ao Choque Térmico , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Carne , Estresse Oxidativo , Aves Domésticas , Doenças das Aves Domésticas/metabolismo , Doenças das Aves Domésticas/microbiologiaRESUMO
This study reports the photocatalytic degradation of Methylene Blue (MB) dye (a class of dyestuffs that are resistant to biodegradation) under the influence of UV-light irradiation. Antibacterial and antibiofilm activities of ferrite nanoparticles (FO NPs) were examined against some pathogenic bacteria isolated from the medical operating room surfaces. In the same context, metals-substituted spinel cobalt ferrite nanoparticles with nominal composition [MxCo1-xFe2O4 NPs; (Mâ¯=â¯Zn, Cu, Mn; xâ¯=â¯0.0, 0.25, 0.5 and 0.75)] were synthesized by citrate sol-gel method. Also, the structures of the synthesized FO NPs were characterized by X-ray diffraction, and Williamson-Hall (WH) method was used to determine the crystallite size. The estimated specific surface area is found in the range from 37.99 to 107.05â¯m2/g, between the synthesized ferrites, Zn0.5Co0.5Fe2O4 NPs have average pore radius 1.84â¯nm and the pore volume was 0.136â¯ml/g. SEM images revealed that, the synthesized FO NPs have an unique pores and uniformly distribution, while EDX spectra shows the elemental composition for the synthesized FO NPs. The elastic properties of FO NPs have been estimated using FTIR data, whereas (Mâ¯-â¯H) hysteresis loops revealed that, by replacing cobalt ions with Zn, Cu, and Mn ions the magnetic behaviour changed from ferromagnetic to paramagnetic. Results obtained from the photocatalysis indicated that Mn0.75Co0.25Fe2O4 NPs (30.0â¯mg) were a promising photocatalyst achieving 96.0% removal of MB after 100â¯min of UV-light exposure in the alkaline solution. Antibacterial results showed that the most effective combination was Zn0.75Co0.25Fe2O4 NPs (20.0â¯ppm) displaying activity against Staphylococcus aureus, Enterococcus columbae, and Aerococcus viridians by 15.0, 13.0, and 12.0â¯mm ZOI, respectively. Additionally, Zn0.75Co0.25Fe2O4 NPs were active as antibiofilm factors producing activity by 63.7, 57.9, and 45.5% towards S. aureus, A. viridians, and E. columbae, respectively. Accordingly, Zn0.75Co0.25Fe2O4 and Mn0.75Co0.25Fe2O4 NPs can be utilized in industrial, biological and medical applications.
Assuntos
Óxido de Alumínio/farmacologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Cobalto/farmacologia , Compostos Férricos/farmacologia , Bactérias Gram-Positivas/efeitos dos fármacos , Óxido de Magnésio/farmacologia , Metais/farmacologia , Nanopartículas/química , Óxido de Alumínio/síntese química , Antibacterianos/síntese química , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Bactérias Gram-Positivas/crescimento & desenvolvimento , Óxido de Magnésio/síntese química , Azul de Metileno/metabolismo , Análise Espectral , Difração de Raios XRESUMO
Water pollution and antimicrobial resistance (AMR) have become two global threats; 80% of diseases and 50% of child deaths are due to poor water quality. In this study, hydrothermal processing was employed to manufacture manganese oxide nanorods. Silver dopant was deposited on the surface of manganese oxide. XRD diffractogram confirmed the facile synthesis of Ag/Mn2O3 nanocomposite. XPS survey analysis demonstrated silver content of 9.43 atom %. Photocatalytic measurements demonstrated the outstanding efficiency of the Ag-Mn2O3 compared to virgin oxide particles under visible radiation. Degradation efficiencies Mn2O3 and Ag/Mn2O3 on methyl orange (MO) dye was found to be 53% and 85% under visible spectrum. Silver dopant was found to decrease the binding energy of valence electrons; this action could support electron-hole pair generation under visible spectrum and could promote catalytic performance. Ag/Mn2O3 NPs demonstrated most effective performance (95% removal efficiency) at pH 3; this could be ascribed to the electrostatic attraction between positively charged catalyst and the negatively charged MO. Ag/Mn2O3 demonstrated enhanced antibacterial activity against Gram-positive Staphylococcus aureus (S. aureus) (19 mm ZOI), and Gram-negative Escherichia coli (E. coli) (22 mm ZOI) respectively; the developed nanocomposite demonstrated advanced anti-film activity with inhibition percentage of 95.5% against E. coli followed by 89.5% against S. aureus.
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Escherichia coli , Compostos de Manganês , Nanocompostos , Óxidos , Prata , Staphylococcus aureus , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Óxidos/química , Óxidos/farmacologia , Prata/química , Prata/farmacologia , Nanocompostos/química , Catálise , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Luz , Compostos Azo/química , Compostos Azo/farmacologia , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/síntese química , Processos FotoquímicosRESUMO
Zinc ferrite nanoparticles (ZnF NPs) were synthesized by a green method using Psidium guava Leaves extract and characterized via structural and optical properties. The surface of ZnF NPs was stabilized with citric acid (CA) by a direct addition method to obtain (ZnF-CA NPs), and then lipase (LP) enzyme was immobilized on ZnF-CA NPs to obtain a modified ZnF-CA-LP nanocomposite (NCs). The prepared sample's photocatalytic activity against Methylene blue dye (MB) was determined. The antioxidant activity of ZnF-CA-LP NCs was measured using 1,1-diphenyl-2-picryl hydrazyl (DPPH) as a source of free radicals. In addition, the antibacterial and antibiofilm capabilities of these substances were investigated by testing them against gram-positive Staphylococcus aureus (S. aureus ATCC 25923) and gram-negative Escherichia coli (E. coli ATCC 25922) bacterial strains. The synthesized ZnF NPs were discovered to be situated at the core of the material, as determined by XRD, HRTEM, and SEM investigations, while the CA and lipase enzymes were coated in this core. The ZnF-CA-LP NCs crystallite size was around 35.0 nm at the (311) plane. Results obtained suggested that 0.01 g of ZnF-CA-LP NCs achieved 96.0% removal of 5.0 ppm of MB at pH 9.0. In-vitro zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) results verified that ZnF-CA-LP NCs exhibited its encouraged antimicrobial activity against S. aureus and E. coli (20.0 ± 0.512, and 27.0 ± 0.651 mm ZOI, respectively) & (1.25, and 0.625 µg/ml MIC, respectively). ZnF-CA-LP NPs showed antibiofilm percentage against S. aureus (88.4%) and E. coli (96.6%). Hence, ZnF-CA-LP NCs are promising for potential applications in environmental and biomedical uses.
Assuntos
Nanopartículas de Magnetita , Nanopartículas Metálicas , Psidium , Nanopartículas Metálicas/química , Enzimas Imobilizadas , Lipase , Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade MicrobianaRESUMO
Spraying a tertiary blend of the insecticides (hexythiazox, imidacloprid, and thiamethoxam), on tomato fruits, is a routine in agriculture-attentive countries. A simple green sample preparation technique was developed and applied to the field samples. Specific HP-TLC and RP-HPLC methodologies are established to estimate the residual insecticides and applied to the prepared field specimens. In the planner chromatographic methodology, methanol:chloroform:glacial acetic acid:triethyl amine (8.5:1.5:0.2:0.1, v/v) is recommended as a mobile system. The other one is columnar chromatography; acetonitrile: water (20:80, v/v), pH 2.8, is recommended as a mobile system. The validation parameters were examined following the ICH rules. The means percentages and standard deviations of the accuracy of the HP-TLC method for the determined compounds were 99.66 ± 0.974, 99.41 ± 0.950, and 99.89 ± 0.983, correspondingly. The values were 99.24 ± 0.921, 99.69 ± 0.681, and 99.20 ± 0.692, correspondingly, when they were determined by the RP-HPLC method. The relative standard deviation percentages of the methods' repeatability and intermediate precision ranged from 0.389 to 0.920. Both methods were highly specific having resolution factors of ≥ 1.78 and selectivity factors of ≥ 1.71. They were applied to the field samples perfectly.
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Inseticidas , Resíduos de Praguicidas , Solanum lycopersicum , Inseticidas/análise , Projetos de Pesquisa , Resíduos de Praguicidas/análise , Cromatografia Líquida de Alta Pressão/métodosRESUMO
Hydroxyapatite (HA), the most common bioceramic material, offers attractive properties as a catalyst support. Highly crystalline mono-dispersed silver doped hydroxyapatite (Ag-HA) nanorods of 60 nm length was developed via hydrothermal processing. Silver dopant offered enhanced chemisorption for crystal violet (CV) contaminant. Silver was found to intensify negative charge on the catalyst surface; in this regard enhanced chemisorption of positively charged contaminants was accomplished. Silver dopant experienced decrease in the binding energy of valence electron for oxygen, calcium, and phosphorous using X-ray photoelectron spectroscopy XPS/ESCA; this finding could promote electron-hole generation and light absorption. Removal efficiency of Ag-HA nanocomposite for CV reached 88% after the synergistic effect with 1.0 mM H2O2; silver dopant could initiate H2O2 cleavage and intensify the release of active ȮH radicals. Whereas HA suffers from lack of microbial resistance; Ag-HA nanocomposite demonstrated high activity against Gram-positive (S. aureus) bacteria with zone of inhibition (ZOI) mm value of 18.0 mm, and high biofilm inhibition of 91.1%. Ag-HA nanocompsite experienced distinctive characerisitcs for utilization as green bioceramic photocatalyst for wastewater treatment.
Assuntos
Peróxido de Hidrogênio , Purificação da Água , Prata/farmacologia , Staphylococcus aureus , Antibacterianos/farmacologia , Durapatita , Violeta GencianaRESUMO
In this study, CoFe2O4 nanoparticles were prepared by the co-precipitation method then surface modified with Capsaicin (Capsicum annuum ssp.). The virgin CoFe2O4 NPs and Capsaicin-coated CoFe2O4 NPs (CPCF NPs) were characterized by XRD, FTIR, SEM, and TEM. The antimicrobial potential and photocatalytic degradation efficiencies of the prepared samples via Fuchsine basic (FB) were investigated. The results revealed that CoFe2O4 NPs have spherical shapes and their diameter varied from 18.0 to 30.0 nm with an average particle size of 25.0 nm. Antimicrobial activity was tested on Gram-positive (S. aureusATCC 52923) and Gram-negative (E. coli ATCC 52922) by disk diffusion and broth dilution methods to determine the zone of inhibition (ZOI) and minimum inhibitory concentration (MIC), respectively. UV-assisted photocatalytic degradation of FB was examined. Various parameters affecting the photocatalytic efficiency such as pH, initial concentration of FB, and dose of nanocatalyst were studied. The in-vitro ZOI and MIC results verified that CPCF NPs were more active upon Gram-Positive S. aureus ATCC 52923 (23.0 mm ZOI and 0.625 µg/ml MIC) than Gram-Negative E. coli ATCC 52922 (17.0 mm ZOI and 1.250 µg/ml MIC). Results obtained from the photocatalytic activity indicated that the maximum FB removal achieving 94.6% in equilibrium was observed using 20.0 mg of CPCF NPS at pH 9.0. The synthesized CPCF NPs were effective in the removal of FB and also as potent antimicrobial agent against both Gram-positive and Gram-negative bacteria with potential medical and environmental applications.
Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Antibacterianos/farmacologia , Antibacterianos/química , Capsaicina/farmacologia , Escherichia coli , Staphylococcus aureus , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Cobalto/química , Testes de Sensibilidade Microbiana , Nanopartículas Metálicas/químicaRESUMO
This study presents the synthesis and doping of reduced graphene oxide (rGO) with synthesized porphyrin (5,15-bisdodecyl porphyrin, C12P) nanoparticles to fabricate reduced graphene oxide-porphyrin (rGO-P) nanocomposite as well as demonstrates their outstanding removal activity of azo dye and antimicrobial potential. The synthesized porphyrin, rGO, and rGO-P nanocomposites were characterised using SEM, HRTEM, Raman spectroscopy, XRD, 1H-NMR, mass spectrometry, and UV-Visible spectroscopy. The ability of the synthesized rGO-P nanocomposite was then investigated (as catalyst and/or adsorbent) to impact its removal efficacy against Congo red (CR) as a well-known toxic, mutagenic and carcinogenic synthetic dye. The findings indicated that 0.01 g of rGO-P nanocomposite achieved 78.0% removal of CR at pH 3.0. Besides, the removal efficacy was evaluated while studying many aspects i.e. pH, CR initial concentration, and rGO-P nanocomposite amount. Moreover, the minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) of antimicrobial activity against pathogenic bacteria and yeast were evaluated. The antimicrobial results showed that rGO-P nanocomposite revealed the greatest antimicrobial activity against Candida albicans, Enterococcus faecalis, and Staphylococcus aureus with ZOI values of 24.3, 21.8, and 22.1 mm, respectively. Consequently, it demonstrates the substantial potential of rGO-P nanocomposite in the effective removal of pollutant dyes as well as significant antibacterial and antifungal properties.
Assuntos
Poluentes Ambientais , Grafite , Nanocompostos , Porfirinas , Purificação da Água , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos , Compostos Azo , Corantes , Vermelho Congo , Grafite/química , Nanocompostos/química , Porfirinas/farmacologiaRESUMO
Service value is a crucial dominant indicator in customer decision-making. However, there is a lack of hospitality literature that investigates the multi-dimensional service value in emerging markets. Thus, this study aims to create a multi-dimensional scale for service value and to analyze how different service value dimensions affect customers repurchase intentions at fast-food restaurants. We make a conceptual framework with eight constructs, including service value and repurchase intention. A self-administrated questionnaire is used to gather empirical data from fast-food restaurant customers in Egypt. We employ confirmatory factor analysis to extract the model's reliability and validity. Moreover, we use a structural equation model to extract the model regressions and correlations using AMOS software. We find that each of the eight proposed service value variables impacts fast-food restaurant customers' repurchase intention. However, the factors that strongly influence customers' preferences to make more purchases are service equity, confidence benefits, service quality, and service reputation. We contribute to the literature on hospitality customer value and repurchasing intentions by presenting a comprehensive multi-dimensional service value framework that affects customers' repurchase intentions in fast-food restaurants. Practically, eight service value variables can help managers of fast-food restaurants meet customer needs and gain a competitive advantage. We suggest many crucial recommendations to restaurant managers regarding the priority of the service value constructs. For example, managers should consider service equity, service quality, and service reputations as a priority of the restaurant service value.
Assuntos
Comportamento do Consumidor , Restaurantes , Reprodutibilidade dos Testes , Fast Foods , IntençãoRESUMO
Due to modern industrialization and population growth, access to clean water has become a global challenge. In this study, a metal-semiconductor heterojunction was constructed between Cu NPs and the Co0.5Ni0.5Fe2O4/SiO2/TiO2 composite matrix for the photodegradation of potassium permanganate, hexavalent chromium Cr(VI) and p-nitroaniline (pNA) under UV light. In addition, the electronic and adsorption properties after Cu loading were evaluated using density functional theory (DFT) calculations. Moreover, the antimicrobial properties of the prepared samples toward pathogenic bacteria and unicellular fungi were investigated. Photocatalytic measurements show the outstanding efficiency of the Cu-loaded nanocomposite compared to that of bare Cu NPs and the composite matrix. Degradation efficiencies of 44% after 80 min, 100% after 60 min, and 65% after 90 min were obtained against potassium permanganate, Cr(VI), and pNA, respectively. Similarly, the antimicrobial evaluation showed high ZOI, lower MIC, higher protein leakage amount, and cell lysis of nearly all microbes treated with the Cu-loaded nanocomposite.
Assuntos
Nanocompostos , Poluentes Químicos da Água , Antibacterianos/farmacologia , Catálise , Luz , Permanganato de Potássio , Dióxido de Silício , Titânio/farmacologia , Raios UltravioletaRESUMO
Porphyria is a challenging metabolic disease due to its heterogeneous presentation symptoms and its difficult diagnosis. Many affected individuals can complain of recurrent neuro-visceral attacks per year, some of which may be persistent and life-threatening, which is confusing if there is no established diagnosis. Although the motor manifestations, autonomic changes and seizure are highly suggestive, the diagnosis is often overlooked and needs confirmatory genetic testing. To the best of our knowledge, the acute intermittent porphyria (AIP) reported in this case, involving severe electrolyte disturbances and rapid severe weakness is a challenging neuro-metabolic case and is extremely rare worldwide. Here, we reported a case of AIP in a young girl who presented to the emergency department of Al-Araby international Hospital, Monufia, Egypt with severe abdominal pain, constipation, and headache which had started 10 days ago. It seems that the diagnosis of porphyria should be considered particularly in those patients with abdominal complaints associated with electrolyte disturbances, seizures, and severe progressive neuropathy.
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This study involves spectroscopic analysis of pesticide residues extracted from tomato, one of the most freshly eaten fruit all over the world. In Egypt, tomato can be protected against pests infection by concomitantly spraying three pesticides namely, acetamiprid (AC), flutolanil (FL) and etofenprox (ET). The three pesticides have been simply and efficiently extracted from the fruits and analyzed by applying the following methods: Differential dual wavelength method, where AC, FL and ET were determined by amplitudes subtraction at 264.8-277 nm, 229-241 nm and 225.6 and 243 nm, respectively after obtaining their first derivative spectra. Modified ratio difference method, where the difference in amplitude values at 261.2 and 241 nm, 273.4 and 236.8 nm and 269.8 and 232 nm was used for determination of AC, FL and ET, respectively. The third method includes recording the amplitudes at 284, 293 and 224 nm for AC, FL and ET, respectively, after mean centering of their spectra. The linear ranges were 1-11, 0.2-2.5 and 0.2-2.5 µg mL-1 for AC, FL and ET, respectively. The methods were proven to be green regarding the Eco-Scale calculations. The methods were efficiently applied for determination of AC, FL and ET in their commercial forms and field trials, where the residues were approximately equal to or below their specified maximum residue limits.
Assuntos
Anilidas/análise , Neonicotinoides/análise , Resíduos de Praguicidas/análise , Piretrinas/análise , Solanum lycopersicum/química , Frutas/química , Espectrofotometria Ultravioleta/métodosRESUMO
Combination of pesticides; acetamiprid, flutolanil and etofenprox are usually used for tomato fruits for protecting them against pest infection. Generally, pesticides, residues could be one of the health hazard sources. Two specific simple sensitive chromatographic methods are developed for simultaneous estimation of the concerning pesticides' residues using simple economic steps of field sample preparation. The first method is HP- TLC method. Hexane: methanol: acetone: glacial acetic acid (8:2:0.5:0.1, by volume) is proposed as a developing system. The second one is RP- HPLC. Acetonitrile: water (75:25, v/v) is proposed as a mobile phase. The recommended methods are completely validated regarding ICH guidelines. Their means percentages and standard deviations of accuracy range 100.32⯱â¯0.89 to 99.27⯱â¯0.9. The methods' repeatability and intermediate precision relative standard deviation percentages range 0.395-0.894. They are successfully applied for estimating the pesticides in pure and commercial forms and field samples.
Assuntos
Manipulação de Alimentos , Resíduos de Praguicidas/análise , Piretrinas/análise , Solanum lycopersicum/química , Cromatografia Líquida de Alta Pressão/métodos , Frutas/química , SegurançaRESUMO
In this paper, we report a layer-by-layer approach for the preparation of a concentric recyclable composite (Co x Ni1-x Fe2O4/SiO2/TiO2; x = 0.9) designed for wastewater treatment. The prepared composite was investigated by X-ray diffraction spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy (SEM) supported with energy dispersive X-ray (EDX) spectroscopy to analyze crystallinity, average particle size, morphology and elemental composition, respectively. The antimicrobial activities of the prepared composite have been investigated against multi-drug-resistant bacteria and pathogenic fungi using a variety of experiments, such as zone of inhibition, minimum inhibitory concentration, biofilm formation and SEM with EDX analysis of the treated bacterial cells. In addition, the effects of gamma irradiation (with different doses) and UV irradiation on the antibacterial abilities of the prepared composite have been evaluated. Moreover, the effect of gamma irradiation on the crystallite size of the prepared composite has been studied under varying doses of radiation (25 kGy, 50 kGy and 100 kGy). Finally, the photocatalytic efficiency of the prepared composite was tested for halogen-lamp-assisted removal of pyridine (artificial wastewater). Various parameters affecting the efficiency of the photocatalytic degradation, such as photocatalyst dose, pyridine concentration, pH, point of zero charge and the presence of hydrogen peroxide, have been studied. Our results show that the synthesized composite has a well-crystallized semi-spherical morphology with an average particle size of 125.84 nm. In addition, it possesses a high degree of purity, as revealed by EDX elemental analysis. Interestingly, the prepared composite showed promising antibacterial abilities against almost all the tested pathogenic bacteria and unicellular fungi, and this was further improved after gamma and UV irradiation. Finally, the prepared composite was very efficient in the light-assisted degradation of pyridine and its degradation efficiency can be tuned based on various experimental parameters. This work provides a revolutionary nanomaterial-based solution for the global water shortage and water contamination by offering a new wastewater treatment technique that is recyclable, cost effective and has an acceptable time and quality of water.
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1,4,7,10-Tetraoxa[10](2,8)trögerophane 5 was synthesized from its corresponding precursors. Heating of 2 with p-nitrophenoxide afforded bis(p-nitrophenyl)ether 3, which was treated with hydrazine hydrate to give bis(p-aminophenyl)ether 4. Treatment of 4 with paraformaldehyde and triflouroacetic anhydride gave trögerophane 5. Reaction of 5 with trifluroacetic anhydride afforded phenhomazine derivative 6, which was treated with potassium carbonate to afford tetrahydrophenhomazine 7. Finally, reaction of 7 with phenacylchloride, bromoacetic acid, or ethyl bromoacetate in the presence of triethyl amine under reflux, afforded the corresponding macrocyclic compounds 8, 9 and 10, respectively. The synthesized trögerophane,precursors and its newly synthesized phenhomazines derivatives were screened for anticancer activity. Results revealed that 1,4,7,10-tetraoxa[10](2,8)trögerophane had a promising selectivity towards colon cancer cell line with an IC50 of 92.7 µg/ml.
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With recently increasing the environmental problems and expected energy crisis, it is necessary to synthesis a low-cost, efficient, and UV-light responsive photocatalyst for contaminants' degradation. The nanostructured spinel ferrite Mn0.5Zn0.5-xMgxFe2O4 NPs (x = 0.0, 0.125, 0.25, 0.375 and 0.50) were synthesized via the sol-gel method. The crystallite size was lied in nano regime ranging from 21.8 to 36.5 nm. The surface chemical composition of the Mn0.5Zn0.5-xMgxFe2O4 NPs was investigated via XPS analysis. Mossbauer spectra showed that the peaks were shifted to higher values of the maximum magnetic field as the Mg content increased, indicating that the crystallinity is enhanced while the crystal size is decreased. Also, various parameters such as the photocatalyst dose, dyes concentration, pH, point of zero charge, and the metals leaching were studied. The point of zero charge (PZC) has found at pH = 2.38. The Mn0.5Zn0.125Mg0.375Fe2O4 NPs showed an excellent UV-assisted photocatalytic activity against Chloramine T (90 % removal efficiency) and Rhodamine B (95 % removal efficiency) after 80 min as compared to pure Mn0.5Zn0.5Fe2O4 ferrite NPs. Besides, it a recyclable catalyst at least four times with a negligible reduction of photocatalytic activity with slight elements leaching. Furthermore, the Mn0.5Zn0.25Mg0.25Fe2O4 NPs showed a high antimicrobial activity towards pathogenic bacteria and yeats.
Assuntos
Anti-Infecciosos , Compostos Férricos , Fenômenos Magnéticos , ZincoRESUMO
The novelty of the present work looks in the synthesis of aqueous dispersed selenium nanoparticles (Se NPs) using gamma rays with the aid of various natural macromolecules such as citrus pectin (CP), sodium alginate (Alg), chitosan (CS) and aqueous extract of fermented fenugreek powder (AEFFP) using Pleurotus ostreatus for investigating their impact in vitro toward carcinoma cell. The synthesized Se NPs were characterized by XRD, UV-Vis., DLS, HRTEM, SEM, EDX and FTIR. Nucleation and growth mechanisms were also discussed. The factorial design was applied to examine the importance of multiple parameters on Se NPs production with a special focus on temperature and gamma rays influences. FTIR spectrum exhibited the existence of several functional groups in Se NPs-capping macromolecules. Results revealed that Se NPs' size was dramatically-influenced by the type of stabilizer, precursors concentration, pH and the absorbed gamma rays dose. The current research reported the promising antitumor application of Se NPs against Ehrlich Ascites Carcinoma (EAC) and human Colon Adenocarcinoma (CACO) in vitro. The proliferation of EAC was significantly-hindered by Se NPs-CS (38.0 µg/ml) at 60 kGy (IC50 = 23.12%) and Se NPs-AEFFP (19.00 µg/ml) at 15 kGy (IC50 = 7.21%). Also, Se NPs control the generation of CACO cells, IC50 was recorded as 25.32% for Se NPs-CS (38.0 µg/ml) and 8.57% for Se NPs-AEFFP (19.00 µg/ml).
Assuntos
Quitosana/química , Raios gama , Nanopartículas/química , Pleurotus/metabolismo , Selênio/química , Selênio/farmacologia , Trigonella/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Fermentação , HumanosRESUMO
Water scarcity is now a serious global issue resulting from population growth, water decrease, and pollution. Traditional wastewater treatment plants are insufficient and cannot meet the basic standards of water quality at reasonable cost or processing time. In this paper we report the preparation, characterization and multiple applications of an efficient photocatalytic nanocomposite (CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2/C-dots) synthesized by a layer-by-layer method. Then, the photocatalytic capabilities of the synthesized nanocomposite were extensively-studied against aqueous solutions of chloramine-T trihydrate. In addition, reaction kinetics, degradation mechanism and various parameters affecting the photocatalytic efficiency (nanocomposite dose, chloramine-T initial concentration, and reaction pH) were analyzed in detail. Further, the antimicrobial activities of the prepared nanocomposite were tested and the effect of UV-activation on the antimicrobial abilities of the prepared nanocomposite was analyzed. Finally, a comparison between the antimicrobial abilities of the current nanocomposite and our previously-reported nanocomposite (CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2) had been carried out. Our results revealed that the prepared nanocomposite possessed a high degree of crystallinity, confirmed by XRD, while UV-Vis. recorded an absorption peak at 299 nm. In addition, the prepared nanocomposite possessed BET-surface area of (28.29 ± 0.19 m2/g) with narrow pore size distribution. Moreover, it had semi-spherical morphology, high-purity and an average particle size of (19.0 nm). The photocatalytic degradation efficiency was inversely-proportional to chloramine-T initial concentration and directly proportional to the photocatalyst dose. In addition, basic medium (pH 9) was the best suited for chloramine-T degradation. Moreover, UV-irradiation improved the antimicrobial abilities of the prepared nanocomposite against E. coli, B. cereus, and C. tropicalis after 60 min. The observed antimicrobial abilities (high ZOI, low MIC and more efficient antibiofilm capabilities) were unique compared to our previously-reported nanocomposite. Our work offers significant insights into more efficient water treatment and fosters the ongoing efforts looking at how pollutants degrade the water supply and the disinfection of water-borne pathogenic microorganisms.