Heavy metals (Cd, Cu, Ni and Pb) content in two fish species of Persian Gulf in Bushehr Port, Iran

Heavy metal (HMs) pollution of aquatic environment has become a great concern in recent years. In this study, cadmium (Cd), copper (Cu), nickel (Ni) and lead (Pb) levels were determined in muscle and skin of two important consumed fishes (Indo-Pacific king mackerel and Tigertooth croaker) in Bushehr Province in the Southwestern of Iran. Heavy metal concentrations were analyzed by using inductively coupled plasma (ICP). The mean contents of metal, expressed in mg/kg wet weight, varied from 0.17 to 0.26 for Cd, 1.25 to 1.84 for Cu, 0.6 to 0.84 for Ni and 0.31 to 0.7 for Pb. Results showed that the highest and lowest contents of heavy metals in muscle and skin of both fish samples were related to Cu and Cd concentration, respectively, and heavy metal contents in both skin fish samples and muscle of Tigertooth croaker were found to decrease in sequence as Cu>Pb>Ni>Cd.Key words: Heavy metal, fish, Bushehr, Iran

The Solid Phase Extraction of Some Metal Ions Using Palladium Nanoparticles Attached to Silica Gel Chemically Bonded by Silica-Bonded N-Propylmorpholine as New Sorbent prior to Their Determination by Flame Atomic Absorption Spectroscopy

In this research at first palladium nanoparticle attached to a new chemically bonded silica gel has been synthesized and has been characterized with different techniques such as X-ray diffraction (XRD), fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Then, this new sorbent (chemically modified silica gel with N-propylmorpholine (PNP-SBNPM)) was efficiently used for preconcentration of some metal ions in various food samples. The influence of effective variables including mass of sorbent, flow rate, pH of sample solutions and condition of eluent such as volume, type and concentration on the recoveries of understudy metal ions were investigated. Following the optimization of variables, the interfering effects of some foreign ions on the preconcentration and determination of the investigated metal ions described. At optimum values of variables, all investigated metal ions were efficiently recovered with efficiency more than 95%, relative standard deviation (RSD) between 2.4 and 2.8, and detection limit in the range of 1.4–2.7 ng mL−1. The present method is simple and rapidly applicable for the determination of the understudied metal ions (ng mL−1) in different natural food samples

Natural source-based graphene as sensitising agents for air quality monitoring

Natural carbon powder has been used as a precursor to prepare two main types of sensitising agents of nitrogen-doped carbon nanoparticles (N-CNPs) and nitrogen-doped graphene quantum dots coupled to nanosheets (N-GQDs-NSs) by using simple treatments of chemical oxidation and centrifugation separation. Characterization based on FTIR, XPS, XRD, Raman spectroscopy, FE-SEM, HR-TEM, AFM, UV-Vis and FL, revealed successful doping carbon nanoparticle with nitrogen with an average plane dimension of 50 nm and relatively smooth surface. The versatility of the prepared samples as sensitising agents was developed and established by exploiting its ability for detection of volatile organic compounds via simple optical fibre based sensing configuration. The comparative experimental studies on the proposed sensor performance indicate fast response achieved at a few tens of seconds and excellent repeatability in exposure to the methanol vapour. The low limit of detection of 4.3, 4.9 and 10.5 ppm was obtained in exposure to the methanol, ethanol and propanol vapours, respectively, in the atmosphere condition. This study gives insights into the chemical/physical mechanism of an enhanced economic optical fibre based gas sensor and illustrates it for diverse sensing applications, especially for chemical vapour remote detection and future air quality monitoring

The nature of the relationship between teacher and learner in comprehensive e-learning process with an emphasis on ideas of Deleuze

Background and Objectives: The aim of this research is study the nature of the relationship between teacher and learner in comprehensive e-learning process with an emphasis on ideas of Deleuze. With the expansion of e-learning, one of the important aspects of change in education is in the field of teaching and learning, including the relation between the teacher and the learner. In the analysis and evaluation of the nature of the relation and its role in human cognition, one of the post structuralist emerging paradigms is Deleuze's rhizomatic epistemology. In the area of Deleuze's ideas and electronic learning based on connectivism theory, separate researches have been done. However, what distinguishes this study from other studies is the assessment of the important fact that whether the new area which Deleuze names rhizomatic and by which means challenges the traditional relationships between the teacher and the learner in the tree system and deterritorializes can support the new atmosphere of electronic learning. Do these two accompany each other? MethodS:The methodology of this study is philosophical analysis and deduction, which were used to answer the research question (What is the nature of the relation between the teacher and the learner in the process of e-learning?). The method of data collection is desk-documentation study. Based on concept analysis, valid understanding of the concept and a clear explanation of its relationship with other concepts was achieved. Moreover, based on deductive approach, the implications of the nature of the relation between the teacher and the learner according to Deleuze's ideas in the process of teaching - learning in e-learning was assessed. Then, these were analyzed philosophically. In other words, Deleuze's rhizomatic epistemological concepts and the related elements on the one hand and the concepts of electronic learning based on connectivism theory on the other hand were analyzed, interpreted and clarified. In the end, the proportion of relation in e-learning to Deleuze's rhizomatic relation was evaluated.  Findings: First, basic factors in rhizomatic epistemology of Deleuze were investigated. Based on the findings of this study, the essentialistic of the relationship between the teacher and the learner, according to Deleuze’s opinions, is rhizomatic. This means that it has features such as Interconnection and heterogeneity, pluralism, immigration, mapping, and non-indicative dissociation of rhizome, suggesting nonlinear, horizontal and non-hierarchical, fluid and fragile, decentralizing, spontaneous and molecular, dense and multiplexed, flexible and permeable relationships. Second, the nature of relationship in virtual learning process was illuminated according to the principles of communication theory, which is the new theory of learning in the age of information and communication technology, communication in E-learning is a systemic and network communication that has nonlinear relationships among system components and network.According to this theory, E-learning is the process of network components communicating with each other. At the end, the nature of relationship virtual Learning in relation with, the nature of rhizomatic epistemology of Deleuze was examined Therefore, the orientation of communication in E-learning is in line with Deleuze's rhizomatic relationship. Conclusion: Based on connectivism theory, electronic education is the very process of network elements connecting with each other. Thus, the direction of e-learning is aligned with Deleuze's rhizomatic relation. Thus, Deleuze's rhizomatic relationships with regard to the capabilities it holds, promises the ideal relationship between the teacher and the learner in the E-learning era and can serve as a model to address some of the challenges of the traditional educational system.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Construction of expression vectors carrying mouse peroxisomal protein gene (PeP) with GST and Flag labels

The aim of this study was to construct expression vectors carrying mouse peroxisomal protein gene (PEP-cDNA) in prokaryotic and mammalian expression vectors in chimeric cDNA types, encompassingGST and FLAG with PEP-cDNA. PEP-cDNA was sub-cloned in pGEX6p2 prokaryotic expression vector in order to label this gene with GST to purify PEP protein for further biochemical analysis and identifying related proteins thereafter. FLAG-PEP recombinant DNA was produced and sub-cloned inpUcD3 eukaryotic expression vector to express tagged-PEP protein for transient transfection analysis and identifying intracellular localization of PEP protein in future experiments. PEP-cDNA was amplifiedin different PCR reactions using pEGFP-PEP vector and 2 sets of primers introducing specific restriction sites at the ends of PEP. PCR products with BamHI/SalI restriction sites were treated by restriction enzymes and inserted into the pGEX6p2, downstream of GST tag. PEP-cDNA containingBamHI/ApaI restriction sites and FLAG gene (which amplified using pUcD3-FLAG-PEX3 vector) were used as templates in secondary PCR for amplifying FLAG-PEP recombinant DNA. FLAG-PEP fragment was treated by enzymatic digestion and inserted into the pUcD3 eukaryotic expression vector.pGEX6p2-PEP and pUcD3-FLAG-PEP constructed vectors were transformed into the one shot TOP10 and JM105 bacterial competent cells, respectively. Positive colonies were selected for plasmid preparation. Results confirmed correct amplification of the expected products. PEP-cDNA in both PCRreactions encompasses 630 bp. FLAG fragment containing designed sites was 77 bp and FLAG-PEP fragment was 700 bp. Sequencing of constructed vectors confirmed that PEP-cDNA was tagged appropriately and inserted free of mutation and in frame with GST and FLAG

High CO2 absorption in new amine based-transition-temperature mixtures (deep eutectic analogues) and reporting thermal stability, viscosity and surface tension: Response surface methodology (RSM)

To study CO2 capture potential, three types of transition-temperature mixtures (TTMs) were prepared by mixing ethyltriphenylphosphonium bromide (MTPPB) as a hydrogen bond acceptor (HBA) and n-methyl diethanolamine (MDEA) as a hydrogen bond donor (HBD) in different molar ratios (1:7, 1:10 and 1:16). Fourier transform infrared spectroscopy (FT-IR) results showed that TTMs have almost similar spectra to their HBD (MDEA) with different levels of transmittance and exhibit similar behavior. From the experimental results, it was found that the thermal stability, viscosity and surface tension of TTMs decreased as the concentration of MDEA in the mixture increased. According to response surface methodology (RSM) models and analysis of variance (ANOVA), temperature and molar ratio had a great effect on the viscosity and surface tension of TTMs. Finally, it was found that CO2 solubility in TTMs (at 303.15 K at pressure up to 1.35 MPa) was enhanced as the MDEA quantity increased in the mixture up to 1:10 mol ratio. However, by increasing MDEA concentration to 16:1 mol ratio, there was a decreasing trend in the CO2 solubility data. Also, all TTMs, particularly TTM containing 10:1 mol MDEA (MTPPB-MDEA 1:10) exhibited an equilibrium loading capacity approaching 1 mol CO2 per mole solvent at high pressure, revealing their high potential for CO2 capture. A comparison showed that the CO2 solubility in the studied solvents was higher than that of existing deep eutectic solvents (DESs) and other TTMs as well as several ionic liquids (ILs) to date. To the best of our knowledge, this is the first study to report the CO2 solubility in phosphonium-base TTMs containing MDE

Genetic Variants of Cytochrome b-245, Alpha Polypeptide Gene and Premature Acute Myocardial Infarction Risk in An Iranian Population

Background: Oxidative stress induced by superoxide anion plays critical roles in the pathogenesis of coronary artery disease (CAD) and hence acute myocardial infarction (AMI). The major source of superoxide production in vascular smooth muscle and endothelial cells is the NADPH oxidase complex. An essential component of this complex is p22phox, that is encoded by the cytochrome b-245, alpha polypeptide (CYBA) gene. The aim of this study was to investigate the association of CYBA variants (rs1049255 and rs4673) and premature acute myocardial infarction risk in an Iranian population. Methods: The study population consisted of 158 patients under the age of 50 years, with a diagnosis of premature AMI, and 168 age-matched controls with normal coronary angiograms. Genotyping of the polymorphisms was performed by the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: There was no association between the genotypes and allele frequencies of rs4673 polymorphism and premature acute myocardial infarction (P>0.05). A significant statistical association was observed between the genotypes distribution of rs1049255 polymorphism and AMI risk (P=0.037). Furthermore, the distribution of AA+AG/GG genotypes was found to be statistically significant between the two groups (P=0.011). Conclusions: Our findings indicated that rs1049255 but not rs4673 polymorphism is associated with premature AMI

The effect of L-arginine supplementation on obesity-related indices: A systematic review and meta-analysis of randomized clinical trials

The clinical studies regarding the effect of L-arginine in human anthropometry have not been fully consistent, therefore, we carried out a systematic review and meta-analysis of randomized clinical trials in order to precisely evaluate and quantify the efficacy of L-arginine on weight, waist circumference, and BMI. We searched online databases including PubMed, SCOPUS, and Google Scholar for relevant articles up to September 2017. Eligible articles were reviewed by two independent investigators. Mean differences of the outcomes were used for calculation of weighted mean difference (WMD) derived from the random-effects model. Statistical heterogeneity between studies was examined using Cochran's Q-test and I2index. Funnel plot and Egger's tests were performed to assess the publication bias. In our initial search, we found 1598 publications, of which 8 RCTs (9 treatment arms) were included. The results of the meta-analysis displayed a significant reduction in WC following L-arginine supplementation (WMD: -2.97 cm; 95 CI: -4.75 to -1.18, P = 0.001). However, L-arginine intervention had not elicited a significant effect on BMI (WMD: -0.51 kg/m2; 95 CI: -1.11 to .08, P = 0.09) and body weight (WMD: -0.57 kg; 95 CI: -1.77 to 0.61, P = 0.34). Subgroup analyses displayed that longer-term interventions (�8 weeks) had a positive effect on body weight and using < 8 g/day L-arginine with longer duration (�8 weeks) could significantly decrease BMI. In conclusion, this meta-analysis result suggested L-arginine supplementation could reduce waist circumference without any significant effect on body weight and body mass index. © 2021 Hogrefe Verlag GmbH & Co. KG. All rights reserved

Bioengineered lungs generated from human iPSCs‐derived epithelial cells on native extracellular matrix

The development of an alternative source for donor lungs would change the paradigm of lung transplantation. Recent studies have demonstrated the potential feasibility of using decellularized lungs as scaffolds for lung tissue regeneration and subsequent implantation. However, finding a reliable cell source and the ability to scale up for recellularization of the lung scaffold still remain significant challenges. To explore the possibility of regeneration of human lung tissue from stem cells in vitro, populations of lung progenitor cells were generated from human iPSCs. To explore the feasibility of producing engineered lungs from stem cells, we repopulated decellularized human lung and rat lungs with iPSC‐derived epithelial progenitor cells. The iPSCs‐derived epithelial progenitor cells lined the decellularized human lung and expressed most of the epithelial markers when were cultured in a lung bioreactor system. In decellularized rat lungs, these human‐derived cells attach and proliferate in a manner similar to what was observed in the decellularized human lung. Our results suggest that repopulation of lung matrix with iPSC‐derived lung epithelial cells may be a viable strategy for human lung regeneration and represents an important early step toward translation of this technology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142929/1/term2589.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142929/2/term2589_am.pd