Showing papers by "Islamic Azad University North Tehran Branch published in 2018"
TL;DR: In this article, the packaging properties of the nanocomposite films, such as WVP, moisture sensibility, mechanical properties, and UV-protection, were measured as a function of the content of nano ZnO (1, 3, and 5%).
86 citations
TL;DR: It could be concluded that the multi-functionalized GO as a novel nanocarrier could significantly enhance the ICG loading, stability, and improve its inhibitory effects as a photosensitizer in aPDT against S. mutans.
Abstract: Antimicrobial photodynamic therapy (aPDT) has been emerged as a noninvasive strategy to remove bacterial contaminants such as S. mutans from the tooth surface. Photosensitizer (PS), like indocyanine green (ICG), plays a key role in this technique which mainly suffers from the poor stability and concentration-dependent aggregation. An appropriate nanocarrier (NC) with enhanced antibacterial effects could overcome these limitations and improve the efficiency of ICG as a PS. In this study, various ICG-loaded NCs including graphene oxide (GO), GO-carnosine (Car) and GO-Car/Hydroxyapatite (HAp) were synthesized and characterized by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Filed Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS), Zeta Potential and Ultraviolet-Visible spectrometry (UV–Vis). The colony forming unit and crystal violet assays were performed to evaluate the antimicrobial and anti-biofilm properties of PSs against S. mutans. The quantitative real-time PCR approach was also applied to determine the expression ratio of the gtfB gene in S. mutans. The zeta potential analysis and UV–Vis spectrometry indicated successful loading of ICG onto/into NCs. GO-Car/HAp showed highest amount of ICG loading (57.52%) and also highest aqueous stability after one week (94%). UV–Vis spectrometry analyses disclosed a red shift from 780 to 800 nm for the characteristic peak of ICG-loaded NCs. In the lack of aPDT, GO-Car@ICG showed the highest decrease in bacterial survival (86.4%) which indicated that Car could significantly promote the antibacterial effect of GO. GO@ICG, GO-Car@ICG and GO-Car/HAp@ICG mediated aPDT, dramatically declined the count of S. mutans strains to 91.2%, 95.5% and 93.2%, respectively (P
76 citations
TL;DR: An overview of the delivery systems of Gd nanoparticles in the MRI and NCT would be mentioned, with a view to improving the targetability of the contrast agents and to encapsulate Gd into nanoparticulate materials.
76 citations
TL;DR: The membrane PSF/GO 0.4% with the most negative zeta potential and the highest BPA removal efficiency was determined as the optimal membrane, and the optimum conditions of input pressure, operating time, initial concentration of BPA, and pH were determined.
63 citations
TL;DR: In this article, multilayer perceptron Artificial Neural Network (MLP-ANN) and Least Square Support Vector Machine (LSSVM) were developed to predict the thermal performance and pressure loss.
Abstract: In this study, Multilayer Perceptron Artificial Neural Network (MLP-ANN) model and Least Square Support Vector Machine (LSSVM), were developed to predict the thermal performance and pressure loss o...
56 citations
TL;DR: In this article, an extreme flood occurred on 14 April 2016 in the Karoon River, Iran and the results show that the flood significantly affected the channel width and the main effect was high mobilization of channel sediments and severe bank erosion in the meandering reaches.
52 citations
12 Jun 2018
TL;DR: The thorough design procedure, specifications, and performance of a mobile social robot friend Arash for educational and therapeutic involvement of children with cancer based on their interests and needs are presented.
Abstract: This article presents the thorough design procedure, specifications, and performance of a mobile social robot friend Arash for educational and therapeutic involvement of children with cancer based ...
42 citations
TL;DR: In this paper, the authors investigated the effect of the catalysis amount, oil/alcohol molar ratio, the amount of co-solvent, water amount, reaction temperature, voltage and reaction time on biodiesel production.
39 citations
TL;DR: This paper presents a comprehensive and accurate solution to detect and prevent intrusions in cloud computing systems by using a hybrid method, called HIDCC, and the implementation results show that the intrusion coverage, intrusion detection accuracy, reliability, and availability in cloud Computing systems are considerably increased, and false warnings are significantly reduced.
Abstract: Summary
The rapid growth of distributed computing systems that heavily communicate and interact with each other has raised the importance of confrontation against cyber intruders, attackers, and subversives With respect to the emergence of cloud computing and its deployment all over the world, and because of its distributed and decentralized nature, a special security requirement is needed to protect this paradigm Intrusion detection systems could differentiate usual and unusual behaviors by means of supervising, verifying, and controlling the configurations, log files, network traffic, user activities, and even the actions of different processes by which they could add new security dimensions to the cloud computing systems The position of the intrusion detection mechanisms in cloud computing systems as well as the applied algorithms in those mechanisms are the 2 main factors in which many researches have focused on The goal of those researches is to uncover intrusions as much as possible and to increase the rate and accuracy of detections while reducing the false warnings Those solutions, however, mainly have high computational loads, low accuracy, and high implementation costs In this paper, we present a comprehensive and accurate solution to detect and prevent intrusions in cloud computing systems by using a hybrid method, called HIDCC The implementation results of the proposed method show that the intrusion coverage, intrusion detection accuracy, reliability, and availability in cloud computing systems are considerably increased, and false warnings are significantly reduced
37 citations
TL;DR: It is concluded that parental morphine consumption in adulthood even before mating has destructive effects on memory state of the male offspring and also leads to tolerance to the rewarding effects of morphine.
34 citations
TL;DR: In this paper, the impact of paleoenvironmental changes across the P-T extinction boundary, variations in eustatic level and diagenesis on the carbonate reservoir quality of the Permo-Triassic Upper Dalan and Kangan formations in the Lavan Gas Field (offshore Zagros).
Abstract: Permo–Triassic (P–T) successions in Iran are known as one of the most extensive carbonate–evaporite sequences in the world, holding prolific hydrocarbon accumulations, such as the gas fields in the Zagros Basin. This study addresses the impact of paleoenvironmental changes across the P–T extinction boundary, variations in eustatic level and diagenesis on the carbonate reservoir quality of the Permo–Triassic Upper Dalan and Kangan formations in the Lavan Gas Field (offshore Zagros). A total of eight lithofacies have been defined and interpreted, representing the shallower parts (inner ramp to shoal) of a carbonate homoclinal ramp. The diagenetic features show the mixing influence of marine, meteoric and burial processes, with prevalence of multistage dolomitization and late meteoric-related imprints. The main dolomitization processes are interpreted to be penecontemporaneous and associated with continuous seawater reflux and high evaporation within the intertidal environment. Combined analysis of facies and petrophysical properties has been utilized to define six rock types, including RT4 (grainstones from oolitic shoals) as the best reservoir, whereas RT1 (supratidal anhydrite) is acting as the main cap rock within the studied carbonate–evaporite sequence. Multiscale characterization of lithological and petrophysical properties suggest that the Upper Dalan Formation has a single reservoir unit (D1), whereas the Kangan Formation may be divided into two reservoir units (K1 and K2). The best reservoir quality is promoted by dissolution and dolomitization associated with late Transgressive Sequence Tracts (TST) to early Highstand Sequence Tracts (HST) sequences, while low reservoir quality corresponds to late HST sequences accompanied by pore-occluded cements. Petrophysical analysis suggest better porosity-permability for the Upper Dalan than for the Kangan Formation. This observation is closely associated with the different nature of lithofacies, where the Kangan Formation contains more fine-grained carbonate rocks, and the higher intensity of porosity-grain dolomitization in the Upper Dalan Formation. This study provides a better understanding on reservoir quality prediction across the P–T boundary and the effect of eustatic fluctuations and diagenesis in controlling porosity-permeability evolution with similar settings elsewhere.
TL;DR: In this paper, the effects of different tannin-rich plants (Rhus coriaria, Eucalyptus, Terminalia chebula, Quercus castaneifolia, Pomegranate) extract as biomordants and alum (as a chemical mordant) with two mordanting procedures (pre- and metamordanting) on color characteristics of the dyed samples were also investigated.
Abstract: In this work, the natural dyeing behavior of woollen yarn with madder (Rubia tinctorum L.) root extract was studied. The effects of different tannin-rich plants (Rhus coriaria, Eucalyptus, Terminalia chebula, Quercus castaneifolia, Pomegranate) extract as biomordants and alum (as a chemical mordant) with two mordanting procedures (pre- and metamordanting) on color characteristics of the dyed samples were also investigated. The CIEDE2000 values, color strength (K/S), washing fastness and tensile property of the mordanted and dyed samples were assessed. Visually, a range of hues from orange to brownish-red were obtained. In general, pre-biomordanted samples with Rhus coriaria (10 %owf), Eucalyptus (10 %owf), Terminalia chebula (5 %owf), Quercus castaneifolia (5 %owf) and Pomegranate (5 %owf) showed almost the same color difference (ΔE00) and wash fastness values compared to those treated with 3 %owf alum. Finally, it was concluded from the comparative studies that the biomordants have good potential to be considered as alternatives to the common chemical mordants.
TL;DR: In this article, three mesopore templates for the growth of ZIF-8 nanoparticles were synthesized and characterized by FT-IR, XRD, FE-SEM and BET analyses, and the sulfur removal performance of prepared hybrids were then investigated by changing temperature from 30 to 50 °C under the operational conditions of 34,000 h−1 space velocity and the feed concentrations of 45,000 and 1300 πm for H2S and CH3CH2SH from gas stream, respectively.
Abstract: New hybrids (MCM-41@Z-8, SBA-15@ZIF-8 and UVM-7@ZIf-8) were synthesized using mesopore templates for the growth of ZIF-8 nanoparticles and characterized by FT-IR, XRD, FE-SEM and BET analyses. The sulfur-removal performance of prepared hybrids were then investigated by changing temperature from 30 to 50 °C under the operational conditions of 34,000 h−1 space velocity and the feed concentrations of 45,000 and 1300 ppm for H2S and CH3CH2SH from gas stream, respectively. The optimum breakthrough capacities for MCM-41@ZIF-8, SBA-15@ZIF-8 and UVM-7@ZIF-8 by setting the temperature at 30 °C were reported as 4.92, 5.21 and 6.12 g S/g sorbent for the removal of hydrogen sulfide and 1.32, 1.30 and 1.47 g S/g sorbent for the removal of ethyl mercaptan, respectively. UVM-7@ZIF-8 was shown as the best nano-adsorbent due to the dual-pore size distribution (pore size: 1.22 and 47.67 nm), and higher BET surface area of about 937.23 m2/g in contrast to MCM-41@ZIF-8 (849.99 m2/g), and SBA-15@ZIF-8 (770.79 m2/g). In addition, the introduction of metal active sites of Zn is associated with the improved properties of synthesized nano-adsorbents compared to the starting mesopore templates. The uptake capability of the synthesized nano-adsorbents have only reduced to about 6–9% and 9–12% after 4 cycles of hydrogen sulfide and ethyl mercaptan adsorption, respectively.
TL;DR: In this paper, a double-sided, sonoloaded nanophotocatalysts (nphs) on 3D porous substrate (3D-PS) was reported for the first time.
Abstract: In this study, sonophotocatalytic decolorization of Begazol Black B by double-sided, sonoloaded nanophotocatalysts (nphs) on 3D porous substrate (3D-PS) was reported for the first time. Sonoloading is a facile fabrication route that allows two-sided loading of nphs on 3D-PS. Morphology of the 3D-PS and the presence of the nphs were studied using field emission scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Moreover, the durability of the nphs on the 3D-PS was studied using X-ray fluorescence. The central composite design based on response surface methodology was employed to find the maximum yield of sonophotocatalytic decolorization and optimize the process variables (initial BBB concentration, initial H2O2 concentration, pH and ultrasonication time). Complete decolorization was achieved at only 40 min treatment under the optimum conditions. Moreover, sonoloaded nphs on 3D-PS exhibited 93% durability after 50 h sonophotocatalytic decolorization. The anticipated values of the decolorization efficiency showed excellent agreement with the experimental values (R2 = 0.9823, Adj-R2 = 0.9657). Furthermore, the kinetic analysis demonstrated that the sonophotocatalytic decolorization followed the Langmuir-Hinshelwood kinetic model. Finally, a comparative study between sonocatalytic, photocatalytic and sonophotocatalytic processes was conducted at the optimum condition. The results revealed that sonophotocatalytic process can markedly enhance the decolorization efficiency compared to sonocatalytic and photocatalytic methods due to the enhanced reactive radical generation.
TL;DR: Using the drilling machine developed in this study and CO2 coolant, orthopedic surgeons can perform tibia drilling in various directions without the risk of thermal necrosis since the internal gas coolants reduce the temperature increase in tibia caused by changing the drilling depth and the drilling direction from radial to longitudinal, greatly.
Abstract: Thermal necrosis is one of the main concerns in bone drillings. This study has been designed with the aim of improving the surgeons' knowledge on how to reduce thermal necrosis in tibia drilling with various depths and directions. A drilling machine was developed, which made the direct transfer of gas coolants into the drilling site during drilling possible. Results indicated that 2000 r/min is the most proper rotational speed for minimizing thermal necrosis. Changing the drilling direction from radial to longitudinal raised the temperature at drilling site. Increasing the drilling depth from 8 to 50 mm raised the temperature by at least 22.5%. Increasing the drilling depth up to 50 mm raised the drilling site temperature above the threshold temperature of tibia thermal necrosis as well as the temperature durability at the drilling site. However, in contrast to conventional cooling modes, using gas coolants, especially CO2, brought the temperature to a level less than the threshold temperature of tibia thermal necrosis and reduced the durability of temperature at the drilling site by at least 1 minute. Using the drilling machine developed in this study and CO2 coolant, orthopedic surgeons can perform tibia drilling in various directions up to the depth of 50 mm without the risk of thermal necrosis since the internal gas coolants, due to their direct contact with the drilling site and the rapid discharge of the chips, reduce the temperature increase in tibia caused by changing the drilling depth and the drilling direction from radial to longitudinal, greatly.
TL;DR: Increased 30% growth of the bacterium has been observed and the subsequent production of biosurfactant and the difference between the experimental results and simulation data were achieved up to 0.17 g/cm3, which confirms the prediction of data by the software due to a difference of less than 14.5%.
TL;DR: It is indicated that intranasal and intraperitoneal administration of LPS has been able to induce the high level of antibodies both in the sera and lavage fluid and confirmed the strategy for using intran asaladministration of antigen.
Abstract: The lipopolysaccharide (LPS) of Vibrio cholerae (V. cholerae) plays an important role in cholera disease and the induction of primary protection. In this study, we evaluate mice humoral immune response in intranasal and intraperitoneal administrated V. cholerae LPS. The results showed that the intranasal administration of LPS–chitosan nanoparticle induced the high level of antibodies compared to intraperitoneal injection of antigen without chitosan (P < .001). These results indicated that intranasal and intraperitoneal administration of LPS has been able to induce the high level of antibodies both in the sera and lavage fluid and confirmed our strategy for using intranasal administration of antigen.
TL;DR: Simultaneous detection of resistance-creating agents could be an important challenge for combination therapy of MDR K. pneumoniae-caused infections.
Abstract: The increasing prevalence of multidrug-resistant Klebsiella pneumoniae strains isolated from hospitals shows the limitation of recent antibiotics used for bacterial eradication. In this study, 81 K. pneumoniae isolates were collected from three hospitals in Tehran. Antibiotic susceptibility test showed the highest rates of resistance to cefotaxim (85.5%) and ceftazidime (78.3%), and the lowest rates of resistance were detected for colistin (16.9%), streptomycin (16.8%), and chloroamphenicol (21.7%). Eleven different resistance patterns were observed. Sixty-six out of 81 isolates (81.5%) were found to be multidrug resistant (MDR), and 35.8% of them belonged to A3 resistance pattern. 7.4% and 66.7% were KPC enzyme and armA gene positive, respectively. RAPD PCR assay of these bacteria showed 5 clusters, 16 single types, and 14 common types, and there was not any correlation between genetic patterns of the isolates and presence of resistance agents. Simultaneous detection of resistance-creating agents could be an important challenge for combination therapy of MDR K. pneumoniae-caused infections.
TL;DR: In this article, the authors proposed a green school rating system for green schools in Iran based on global standards and validated it with qualitative and quantitative measurements including: pseudo-delphi, focus groups, Thurstone Case V, online survey and conjoint analysis.
TL;DR: The authors' results indicated increasing rates of quinolone resistant E.coli strains circulating in hospitals under the study, and dissemination of these strains harboring qnr determinants is of particular concern.
Abstract: Introduction Escherichia coli (E.coli) as an opportunistic pathogen is a major cause of the hospital infections. The main goal of this research was to determine the frequency of quinolone resistance genes (qnr) among E.coli pathotypes isolated from patients with urinary tract infections (UTIs). Material and methods Urine samples were obtained from patients with UTIs in three major hospitals of Mofid, Bu Ali, and Vali-Asr during the year of 2015 in Tehran, Iran. The antibiogram was done for isolated bacterial isolates using nalidixic acid, norfloxacin, gentamicin, streptomycin, and chloramphenicol. Then the plasmids of the bacterial samples were extracted. PCR was used to detect qnr genes. Finally, the PCR products were run on a 1% agarose gel electrophoresis and the results were analyzed by the program SPSS version 22. Results Overall, 100 E.coli strains were isolated from patients with UTIs. The highest resistance rate was against Streptomycin. The frequency of the genes of qnrA, qnrB and qnrS were 0%, 25% and 36%, respectively. Moreover, the presence of the both genes of qnrB and qnrS was recognized in 10% of isolated bacterial strains. Conclusions Our results indicated increasing rates of quinolone resistant E.coli strains circulating in hospitals under the study. Dissemination of these strains harboring qnr determinants is of particular concern.
TL;DR: Partial least squares (PLS), different families of continuous wavelet transform (CWT), and first derivative spectrophotometry (DS) techniques were studied for quantification of Sofosbuvir and Ledipasvir simultaneously without separation step and results showed no significant differences among methods.
TL;DR: The maximum thermal stress resulted from the cold stimulus is double that produced by the hot stimulus, and there is a higher possibility of pain transmission in the lateral walls of the odontoblast and terminal fibril by releasing mediators during the cold stimulation than the hot stimulation.
Abstract: The objective of this study is to compare the thermal stress changes in the tooth microstructures and the hydrodynamic changes of the dental fluid under hot and cold stimuli. The dimension of the microstructures of eleven cats’ teeth was measured by scanning electron microscopy, and the changes in thermal stress during cold and hot stimulation were calculated by 3D fluid–structure interaction modeling. Evaluation of results, following data validation, indicated that the maximum velocities in cold and hot stimuli were − 410.2 ± 17.6 and + 205.1 ± 8.7 µm/s, respectively. The corresponding data for maximum thermal stress were − 20.27 ± 0.79 and + 10.13 ± 0.24 cmHg, respectively. The thermal stress caused by cold stimulus could influence almost 2.9 times faster than that caused by hot stimulus, and the durability of the thermal stress caused by hot stimulus was 71% greater than that by cold stimulus under similar conditions. The maximum stress was on the tip of the odontoblast, while the stress in lateral walls of the odontoblast and terminal fibril was very weak. There is hence a higher possibility of pain transmission with activation of stress-sensitive ion channels at the tip of the odontoblast. The maximum thermal stress resulted from the cold stimulus is double that produced by the hot stimulus. There is a higher possibility of pain transmission in the lateral walls of the odontoblast and terminal fibril by releasing mediators during the cold stimulation than the hot stimulation. These two reasons can be associated with a greater pain sensation due to intake of cold liquids.
27 Jul 2018
TL;DR: It is suggested that use of sugar as an abrasive material, in comparison with pure water jet and bone powder water jet, resulted in improved cutting quality and elevation of water pressure and reduction of traverse speed had a significant effect on improving surface roughness.
Abstract: The abrasive water jet machining is known as a cold cutting process and can be effective for developing cut in the bone in orthopedic surgery to prevent thermal necrosis. This research examined sur...
TL;DR: To the best of the knowledge, this is the most comprehensive molecular genetics study of PKU in Iran, identifying 100 distinct mutations in the PAH gene, including 15 previously unreported mutations.
Abstract: Phenylketonuria (PKU) is an inborn error of amino acid metabolism caused by mutations in the phenylalanine hydroxylase (PAH) gene, characterized by intellectual deficit and neuropsychiatric complications in untreated patients with estimated frequency of about one in 10,000 to 15,000 live births PAH deficiency can be detected by neonatal screening in nearly all cases with hyperphenylalaninemia on a heel prick blood spot Molecular testing of the PAH gene can then be performed in affected family members Herein, we report molecular study of 635 patients genetically diagnosed with PKU from all ethnicities in Iran The disease-causing mutations were found in 611 (9622%) of cases To the best of our knowledge, this is the most comprehensive molecular genetics study of PKU in Iran, identifying 100 distinct mutations in the PAH gene, including 15 previously unreported mutations Interestingly, we found unique cases of PKU with uniparental disomy, germline mosaicism, and coinheritance with another Mendelian single-gene disorder that provides new insights for improving the genetic counseling, prenatal diagnosis (PND), and/or pre-implantation genetic diagnosis (PGD) for the inborn error of metabolism group of disorders
TL;DR: It can be concluded that UA increases SIRT1 activity and mimics Lamin A and AROS behavior in the living cells and increases the affinity of enzyme for both substrates with decreasing Km value, while enhances the Vmax of enzyme.
TL;DR: In this paper, a study was made to determine the pollution status and potential ecological risk of heavy metals in sediment of Persian Gulf, surface sediments were collected seasonally by Peterson grab.
Abstract: This study was made to determine the pollution status and potential ecological risk of heavy metals in sediment of Persian Gulf. Surface sediments were collected seasonally by Peterson grab, and th...
28 Nov 2018
TL;DR: A new platform for a virtual reality social robot (VR-social robot) which could be used as an auxiliary device or a replacement for real social robots, and suggests that the acceptance of a VR-robot is fairly compatible to the real robot.
Abstract: The role of technology in education and clinical therapy cannot be disregarded. Employing robots and computer-based devices as competent and advanced learning tools for children indicates that there is a role for technology in overcoming certain weaknesses of common therapy and educational procedures. In this paper, we present a new platform for a virtual reality social robot (VR-social robot) which could be used as an auxiliary device or a replacement for real social robots. To support the idea, a VR-robot, based on the real social robot Arash, is designed and developed in the virtual reality environment. “Arash” is a social robot buddy particularly designed and realized to improve learning, educating, entertaining, and clinical therapy for children with chronic disease. The acceptance and eligibility of the actual robot among these children have been previously investigated. In the present study, we investigated the acceptability and eligibility of a virtual model of the Arash robot among twenty children. To have a fair comparison a similar experiment was also performed utilizing the real Arash robot. The experiments were conducted in the form of storytelling. The initial results are promising and suggest that the acceptance of a VR-robot is fairly compatible to the real robot since the performance of the VR-robot did not have significant differences with the performance of the real Arash robot. Thereby, this platform has the potential to be a substitute or an auxiliary solution for the real social robot.
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23 Mar 2018TL;DR: The Lactobacillus strains isolated in this research particularly, L. paracasei, could be applied in improving new fermented products, fortified with B-group vitamin that could be applications as substitution for enriching and supplementation with the controversial synthetic vitamins.
Abstract: Background and Objective: B-group vitamins have important roles in many aspects of cellular metabolism and humans cannot synthesize them. So, they should be obtained from external resources. This project provides a new insight into assessing the production of vitamins B3, B6 and B9 by Lactobacillus, isolated from traditional yogurt samples from 3 different cities of Iran; Golpayegan, Sanandaj and Tehran (Damavand). Material and Methods: Following 72 h of anaerobic culture of the Lactic acid bacteria at 37°C in 5% CO 2 , some Lactobacillus species from traditional yogurt samples were isolated and characterized both morphologically and biochemically. Isolates were identified following 16S rRNA PCR-amplification and sequencing. Including Lactobacillus (L.) ozensis strain Gon2-7, L. acidophilus strain KU, L. helveticus strain D76, L. helveticus strain Dpc 4571, L. fermentum strain 1, L. rossiae strain DSM15814T, L. casei strain NCDO, L. delbrueckii strain ATCC 11842, L. crispatus strain MRS 54.4, L. delbrueckii strain SB3 and L. paracasei subsp. tolerans JCM1171 (T). The sequence of L. paracasei subsp. tolerans JCM1171 (T) was submitted to the NCBI. The ability to produce B-group vitamins was evaluated by high performance liquid chromatography. Lactobacillus strains and amount of vitamin B3, B6 and B9 production were analyzed by Analysis of Variance test. Results and Conclusion: Eleven isolates of Lactobacillus species from traditional yogurt samples were identified. Optimal conditions for Lactobacillus growth were pH 5-6 and temperatures 37-40°C. The isolates produced vitamins B3, B6 and B9. L. paracasei subsp. tolerance JCM 1171 (T) showed the highest amount of produced vitamins (p≤0.01) consist of vitamin B6 (1566.17 µg ml -1 ) and B9 (1279.72 µg ml -1 ). L. acidophilus strain KU showed the highest production of vitamin B3 (522.7 µg ml -1 ). L. fermentum produced the highest amount of vitamin B2. These strains are a natural and cost efficient source of vitamin. The Lactobacillus strains isolated in this research particularly, L. paracasei , could be applied in improving new fermented products, fortified with B-group vitamin that could be applied as substitution for enriching and supplementation with the controversial synthetic vitamins. Conflict of interest: The authors declare that there is no conflict of interest.
TL;DR: In this article, the results showed that Fe-MSN has high catalytic activity for decomposition of hydrogen peroxide (catalase activity) and for oxidation of aromatic hydrogen donors such as 3,3′,5, 5,5′-tetramethylbenzidine (TMB), and a reasonable limit of detection (LOD) of 1.2 μM (3σ/slope) and a linear range over 7.2-100 μM.
Abstract: Mesoporous silica nanoparticles (MSNs) have attracted a lot of notice as a platform in nanomaterials due to their specific properties such as large surface area, high pore size and volume, physical stability and uniform structures. The application of pure MSNs in various industries such as the petrochemical and pharmaceutical industries has been developed. The incorporation of metals into MSNs can increase the catalytic activity of MSNs due to their specific properties such as pore size and volume. Modification of MSNs by iron atoms (Fe-MSN) was studied in this research. The Fe-MSN was prepared using a sol–gel method. Here a comprehensive study was conducted on its enzyme mimicking and biocatalytic activities toward the oxidase, peroxidase and catalase enzymes. Hence, the relevant biocatalytic parameters were obtained through the reliable enzyme kinetic models. The results showed that Fe-MSN has high catalytic activity for decomposition of hydrogen peroxide (catalase activity) and for oxidation of aromatic hydrogen donors such as 3,3′,5,5′-tetramethylbenzidine (TMB). This activity can be carried out in the presence of oxygen as an oxidant (oxidase activity) and/or in the presence of a peroxide substrate, e.g. H2O2 (peroxidase activity) to produce the blue-colored product. Consequently, a colorimetric method was developed to determine H2O2 by Fe-MSN indicating a reasonable limit of detection (LOD) of 1.2 μM (3σ/slope) and a linear range over 7.2–100 μM. When Fe-MSN was coupled with glucose oxidase (a bienzymatic sequential detection system) glucose as a substrate can be detected at ≤1.2 μM over an experimental linear range of 4.1–100 μM.
TL;DR: Playing violent game more effectively improved cognitive performances in the players than the football game, and the results showed that salivary cortisol levels significantly decreased after playing both games.
Abstract: Introduction This research investigated the effects of violent and football video games on cognitive functions, cortisol levels, and brain waves. Methods A total of 64 participants competed in a single-elimination tournament. Saliva samples of all players were obtained before and after the games for the assessment of cortisol levels. The cognitive performances of the players were also assessed by paced auditory serial addition test. Moreover, the electroencephalogram recording was conducted during the games. Results The results showed that salivary cortisol levels significantly decreased after playing both games. Also, playing the football game increased reaction time, whereas decreased sustained attention and mental fatigue. Conclusion Conversely, following playing a violent game, the reaction time decreased, and sustained attention and mental fatigue increased. Furthermore, the results of the EEG recording revealed that playing a violent game engaged more brain regions than the football game. In conclusion, playing violent game more effectively improved cognitive performances in the players than the football game.