86 research outputs found
Kinetic and Thermodynamic Studies of Charge-Transfer Complex Formation between Imipramine and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in Acetonitrile and Dichloromethane Solutions
Spectro-kinetic studies revealed the formation of charge-transfer (CT) complex of imipramine as an electron donor with π acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in acetonitrile and dichloromethane solutions. The resulted CT complexes exhibit spectra that were remarkably different fromthose of the donor and acceptor. The stoichiometry of the resulting complex was found to be 1:1 by the method of Job‘s continuous variation. The formation constants and thermodynamic parameters of the resulting electron-donor-acceptor (DA) complexes were determined by Benesi-Hildebrand and van’t Hoff equations, respectively. The time-dependent spectra recorded after mixing donor and acceptor has been related to an immediate formation of DA complex, which is followed by two relatively slow consecutive reactions. The pseudo-first-order rate constants for the formation of the ionic intermediate and the final product have been evaluated at various temperatures by computer fitting of the absorbance-time data to appropriate equations. The activation parameters, i.e. activation energy, enthalpy, and entropy of activation were computed from temperature dependence of the rate constants. The observed results afford evidence concerning the critical role of solvent polarity on the kinetics and stability of the resulting charge transfer complexes. The ionization potential of the donor in the two solvents was estimated and compared with the theoretical values.KEYWORDS Charge-transfer complex, imipramine, DDQ, ionization potential, kinetic, thermodynamic
Green Silver Nanoparticle for Colorimetric Determination of Cyanide in Water Samples
Cyanide ion is highly toxic to human. Cyanide ion is mainly used in processes like electroplating and extraction of silver and gold. Therefore, it can enter the environment and pollute soil and water. In the present work, a colorimetric method based on silver nanoparticle (AgNP) was proposed for detection and determination of cyanide ion. Silver nanoparticle was prepared by carbon dots as reducing agent. Volume of AgNP and concentration of sodium hydroxide were optimized for determination of cyanide ion by AgNP. It was observed that greenly synthesized AgNP can serve as reagent in detection and determination of cyanide ion. In the presence of sodium hydroxide, a method was optimized and a robust model with linear range of 4.0-100.0 μM, limit of detection of 3.8 μM and limit of quantification of 12.7 μM was obtained. In the method presented, the color change of AgNP from yellow to colorless in the presence of cyanide ion was observed. Environmental water samples including spring, well and wastewater were successfully analyzed by this method, which is simple and inexpensive
Wound healing properties and antimicrobial activity of platelet-derived biomaterials
We analyzed the potential antibacterial effects of two different PdB against methicillin-resistant S. aureus and P. aeruginosa. The third-degree burn wound healing effects of PdB was also studied. Blood samples were obtained from 10 healthy volunteers and biological assays of the PdB were performed and the antimicrobial activity against MRSA and P. aeruginosa was determined using disk diffusion (DD), broth microdilution (BMD), and time-kill assay methods. 48 Wistar albino rats were burned and infected with MRSA. Two groups were injected PdB, the control groups were treated with plasma and received no treatment respectively. In the next step, the rats were euthanized and skin biopsies were collected and histopathologic changes were examined. The results of DD and BMD showed that both PdB performed very well on MRSA, whereas P. aeruginosa was only inhibited by F-PdB and was less susceptible than MRSA to PdBs. The time-kill assay also showed that F-PdB has an antibacterial effect at 4 hours for two strains. Histopathological studies showed that the treated groups had less inflammatory cells and necrotic tissues. Our data suggest that PdB may possess a clinical utility as a novel topical antimicrobial and wound healing agent for infected burn wounds. © 2020, The Author(s)
Wound healing properties and antimicrobial activity of platelet-derived biomaterials
We analyzed the potential antibacterial effects of two different PdB against methicillin-resistant S. aureus and P. aeruginosa. The third-degree burn wound healing effects of PdB was also studied. Blood samples were obtained from 10 healthy volunteers and biological assays of the PdB were performed and the antimicrobial activity against MRSA and P. aeruginosa was determined using disk diffusion (DD), broth microdilution (BMD), and time-kill assay methods. 48 Wistar albino rats were burned and infected with MRSA. Two groups were injected PdB, the control groups were treated with plasma and received no treatment respectively. In the next step, the rats were euthanized and skin biopsies were collected and histopathologic changes were examined. The results of DD and BMD showed that both PdB performed very well on MRSA, whereas P. aeruginosa was only inhibited by F-PdB and was less susceptible than MRSA to PdBs. The time-kill assay also showed that F-PdB has an antibacterial effect at 4 hours for two strains. Histopathological studies showed that the treated groups had less inflammatory cells and necrotic tissues. Our data suggest that PdB may possess a clinical utility as a novel topical antimicrobial and wound healing agent for infected burn wounds. © 2020, The Author(s)
Machine Learning for Determining Interactions between Air Pollutants and Environmental Parameters in Three Cities of Iran
Air pollution, as one of the most significant environmental challenges, has adversely affected the global economy, human health, and ecosystems. Consequently, comprehensive research is being conducted to provide solutions to air quality management. Recently, it has been demonstrated that environmental parameters, including temperature, relative humidity, wind speed, air pressure, and vegetation, interact with air pollutants, such as particulate matter (PM), NO2, SO2, O3, and CO, contributing to frameworks for forecasting air quality. The objective of the present study is to explore these interactions in three Iranian metropolises of Tehran, Tabriz, and Shiraz from 2015 to 2019 and develop a machine learning-based model to predict daily air pollution. Three distinct assessment criteria were used to assess the proposed XGBoost model, including R squared (R2), Root Mean Squared Error (RMSE), and Mean Absolute Error (MAE). Preliminary results showed that although air pollutants were significantly associated with meteorological factors and vegetation, the formulated model had low accuracy in predicting (R2PM2.5 = 0.36, R2PM10 = 0.27, R2NO2 = 0.46, R2SO2 = 0.41, R2O3 = 0.52, and R2CO = 0.38). Accordingly, future studies should consider more variables, including emission data from manufactories and traffic, as well as sunlight and wind direction. It is also suggested that strategies be applied to minimize the lack of observational data by considering second-and third-order interactions between parameters, increasing the number of simultaneous air pollution and meteorological monitoring stations, as well as hybrid machine learning models based on proximal and satellite data
Prevalence and molecular epidemiology of ceftaroline non-susceptible methicillin-resistant Staphylococcus aureus isolates, first clinical report from Iran
Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major pathogens in Iran with a high prevalence and a high level of antibiotic resistance. Ceftaroline is a fifth generation cephalosporin binding and inhibiting penicillin binding protein (PBP2a). Methods: In the present study, 228 clinical MRSA isolates were collected from four cities of Iran and their susceptibility to ceftaroline was evaluated by E-test and the disk diffusion method. Results: Our results showed a high susceptibility rate (97.3) to ceftaroline in MRSA strains from Iran. Six isolates were found to be ceftaroline non-susceptible (CPT-NS) with Minimum inhibitory concentration (MIC) �2 mg/mL. All CPT-NS isolates were isolated from blood and tracheal aspirate and belonged to SCCmec type III as well as agr type I and were all susceptible to vancomycin. Out of six isolates, three, two and one belonged to spa type t030, t4864, and t969, respectively. Vancomycin, quinupristin/dalfopristin, linezolid, chloramphenicol, and tigecycline were the most active agents against CPT-NS isolates. Conclusion: Due to the broad-spectrum activity and low toxicity of ceftaroline as well as the increased rate of vancomycin resistance among MRSA strains in recent years, ceftaroline can be considered as a novel approach to treat MRSA-induced infections. © 2020 The Author(s)
Pharmacological effects of Safranal: An updated review
Safranal (a monoterpene aldehyde) is the major volatile component of saffron which is responsible for the saffron unique odor. Several studies have shown the pharmacological activities of safranal including anti-oxidant, anti-inflammatory, cardioprotective, neuroprotective, nephroprotective, gastrointestinal protective, etc. This study was designed to review the pharmacological and medical effects of safranal and up-to-date previous knowledge. Moreover, some patents related to the pharmacological effects of safranal were gathered. Therefore, electronic databases including Web of Sciences, Scopus, and Pubmed for pharmacological effects and US patent, Patentscope, and Google Patent for patents were comprehensively searched by related English keywords from 2010 to June 2022. According to our review, most of the studies are related to the safranal effects on CNS such as antianxiety, analgesic, anticonvulsant, antiischemic, anti-tremor, memory enhancement and its protective effects on neurodegenerative disorders such as Alzheimer’s, Parkinson and Huntington diseases. Other effects of safranal are antiasthmatic, antihypertensive, antiaging, anticataract, etc. Moreover, the protective effects of this agent on metabolic syndrome and diabetic nephropathy have been shown. Different mechanisms including anti-oxidant, anti-inflammatory, muscle relaxation, antiapoptotic, and regulatory effects on the genes and proteins expression related to signaling pathways of oxidative stress, inflammation, apoptosis, proliferation, etc. are involved in safranal pharmacological effects. Some patents for the prevention and/or treatment of different diseases such as liver cancer, sleep disorder, depression, cognitive disorder, obesity and PMS were also included. Based on the documents, safranal is considered a promising therapeutic agent although more clinical studies are needed to verify the beneficial effects of safranal in humans
Association between colorectal cancer and Fusobacterium nucleatum and Bacteroides fragilis bacteria in Iranian patients: a preliminary study
Background and aim: Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC). Therefore, in this study, the relative abundance of Fusobacterium nucleatum, Bacteroides fragilis, Streptococcus bovis/gallolyticus, and Enteropathogenic Escherichia coli (EPEC) in CRC tissues, and their association with clinicopathologic characteristics of CRC was investigated in Iranian patients. Moreover, the role of these bacteria in the CRC-associated mutations including PIK3CA, KRAS, and BRAF was studied. Method: To these ends, the noted bacteria were quantified in paired tumors and normal tissue specimens of 30 CRC patients, by TaqMan quantitative Real-Time Polymerase Chain Reaction (qPCR). Next, possible correlations between clinicopathologic factors and mutations in PIK3CA, KRAS, and BRAF genes were analyzed. Results: In studied samples, B. fragilis was the most abundant bacteria that was detected in 66 and 60 of paired tumor and normal samples, respectively. Furthermore, 15 of the B. fragilis-positive patients were infected with Enterotoxigenic B. fragilis (ETBF) in both adenocarcinoma and matched adjacent normal samples. F. nucleatum was also identified in 23 of tumors and 13 of adjacent normal tissue samples. Moreover, the relative abundance of these bacteria determined by 2-�CT was significantly higher in CRC samples than in adjacent normal mucosa (p < 0.05). On the other hand, our findings indicated that S. gallolyticus and EPEC, compared to adjacent normal mucosa, were not prevalent in CRC tissues. Finally, our results revealed a correlation between F. nucleatum-positive patients and the KRAS mutation (p = 0.02), while analyses did not show any association between bacteria and mutation in PIK3CA and BRAF genes. Conclusion: The present study is the first report on the analysis of different bacteria in CRC tissue samples of Iranian patients. Our findings revealed that F. nucleatum and B. fragilis might be linked to CRC. However, any link between gut microbiome dysbiosis and CRC remains unknown. © 2021, The Author(s)
Combining ability and heterosis for some canola characteristics sown on recommended and late planting dates using biplot
Canola (Brassica napus L.) is one of the most efficient oil-producing crops in arid and semi-arid regions of the world. In the current study, ten winter canola genotypes [seven genotypes as lines (Zarfam (L1), Talaye (L2), SLM046 (L3), Geronimo (L4), Modena (L5), Opera (L6) and Symbol (L7)] and three genotypes as testers [Okapi (T1), Licord (T2) and Orient (T3)] and their F1 hybrids (21 hybrids) were evaluated to determine the genetic parameters for grain yield, oil content, meal and seed glucosinolate contents under two different planting date [recommended (late September) and late planting (late October)]. According to combined analysis of variance there were significant differences among the genotypes for most studied traits. The genotype main effect and genotype × environment interaction (GGE) biplot method was used for analyzing line × tester design data. Among the lines, L5 showed high negative general combining ability (GCA) effect for meal glucosinolate content in both conditions whereas L1, L5 and L6 revealed high negative GCA effects for seed glucosinolate content in both planting date. From the results, it could be concluded that, hybridization between T1×L1, T1×L6 or T3×L5 is an efficient approach to release genotypes with low seed and meal glucosinolate content. Furthermore, to develop canola cultivars with higher seed and oil yield, hybridization between T1×L7 or T2×L7 is highly recommended. Improved oil content will be achieved if T1×L5, T2×L5 or T3×L6 hybrids are implemented into the breeding programs.</p
Leveraging Multiple Linear Regression for Wavelength Selection
In multivariate calibration, wavelengths selection is often used to lower prediction errors of sample properties. As a result, many methods have been created to select wavelengths. Several of the wavelength selection methods involve many tuning parameters that are typically complex or difficult to work with. The purpose of this poster is to show an easy way to select wavelengths while using few simple tuning parameters. The proposed method uses multiple linear regression (MLR) as an indicator to which wavelengths should be used to create a model. From a collection of random MLR models, those models with an acceptable bias/variance balance are evaluated to determine the wavelengths most frequently used. Portions of the most frequently selected wavelengths are chosen as the final MLR selected wavelengths. These MLR selected wavelengths are used to produce a calibration model by the method of partial least squares (PLS). This proposed wavelength selection method is compared to PLS models containing all wavelengths using several near infrared data sets. The PLS models with the selected wavelengths show an improvement in prediction error, suggesting this method as a simple way to select wavelengths
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