Influence of amine group on the adsorptive removal of basic dyes from water using two nanoporous isoreticular Zn(II)-based metal organic frameworks

Dyes are the most abundant hazardous components existing in the environment because of their extensive use in industries. So, in the present study, two isoreticular Zn(II)-MOFs, TMU-16 and TMU-16-NH2, were used for the adsorptive removal of harmful cationic dyes from aquatic medium. In order to improve the removal efficiency, optimization of the experimental conditions was carried out as a function of pH, MOF dosage, dye concentration and contact time. The maximum removal capacity was obtained at pH 12, 10 mg of MOF and 20 min as the contact time. The adsorption isotherms of each dye over both sorbents matched with the Langmuir model, and the adsorption kinetics followed the pseudo-second order kinetic model. The dye adsorption over TMU-16-NH2 is higher than that over TMU-16, indicating that the addition of amine groups in MOF network played an important role in the adsorption process, because of electrostatic interactions and hydrogen bonding. Thermodynamic studies indicated that adsorption process is spontaneous and endothermic

HIV/AIDS-related knowledge and perceptions among medical students in Isfahan University of Medical Sciences: a theory-based cross-sectional study

Background and Aims: Health care personnel are at occupational risk of blood-transmitted pathogens such as; HBV, HCV, and HIV. Educational interventions must be designed for this vulnerable group before entering workplaces. Medical sciences universities are the best places for designing such interventions, and also, academic duration is the best time for that. Assessing current situation is considered as a primary phase of designing programs. This study has been carried out for assessing knowledge and health beliefs of Isfahan medical students toward HIV/AIDS in 2009.Material and Methods: The present study is a cross-sectional research. All the 1st year students of Isfahan medical school (disciplines of medicine, anesthesia, and laboratory sciences) in 2009-2010 (n=175) participate in this study. Data gathering instrument were demographic questionnaire and scales (knowledge, perceived susceptibility, and perceived severity) that designed by the authors. For validity of the designed tools, two methods of face and content validity were applied using expert panel. The tools reliability was done by two methods (test-retest & internal consistency, Cronbach’s Alpha). Participation of students in research was voluntary and with informed consent. SPSS 16.0 software was used for data analysis in this research.Results: Based on findings, 99.4% of all students have high level of knowledge about HIV/AIDS. Also, results showed 50.6% and 64.6% of samples have respectively high levels of perceived susceptibility and perceived severity. There was no significant correlation between demographic variables and main factors of research (knowledge, perceived susceptibility, and perceived severity).Conclusion: Although, knowledge of medical students was desired and acceptable, but this result dose not means that these students do not need HIV/AIDS education. Perceived susceptibility and perceived severity of students is not acceptable, and thus educational interventions are seriously needed.Key words: Knowledge, Health Belief, Perceived Susceptibility, Perceived Severity, Students, HIV/AIDS

A Certified Access Controller for JME-MIDP 2.0 enabled Mobile Devices

Mobile devices, like cell phones and PDAs, allow to store information and to establish connections with external entities. In this sort of devices it is important to guarantee confidentiality and integrity of the stored data as well as ensure service availability. The JME platform, a Java enabled technology, provides the MIDP standard that facilitates applications development and specifies a security model for the controlled access to sensitive resources of the device. This paper describes a high level formal specification of an access controller for JME-MIDP 2.0. This formal definition of the controller has been obtained as an extension of a specification, developed using the Calculus of Inductive Constructions and the proof assistant Coq, of the MIDP 2.0 security model. The paper also discusses the refinement of the specification into an executable model and describes the algorithm which has been proven to be a correct implementation of the specified access controller

Flavin mononucleotide-exfoliated graphene flakes as electrodes for the electrochemical determination of uric acid in the presence of ascorbic acid

Gold interdigitated microelectrodes (Au-IDA) modified with either graphene flakes exfoliated using flavin mononucleotide (FMN) (Gr-FMN) or graphene flakes and platinum nanoparticles (Pt-Gr-FMN) have been studied in the oxidation of uric acid (UA). An electrochemical method for the detection and quantification of UA in phosphate buffer solution at physiological pH (PBS, 0.25 M, pH 7) in the absence and presence of ascorbic acid (AA) has been studied by cyclic voltammetry. The quantification of UA was investigated by cyclic voltammetry, presenting an oxidation peak at 0.99 V with both modified electrodes. Linearity range of 60–578 μM and 60–345 μM has been found for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA electrodes, respectively. Limits of detection of 18 μM were obtained for both electrodes, and the repeatability was studied at 177 μM providing 4% and 8% for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA, respectively. AA interference has been studied by cyclic voltammetry, showing two clearly separated oxidation peaks, at 0.99 V for UA oxidation and at 0.74 V for Gr-FMN/Au-IDA and 0.70 V for Pt-Gr-FMN/Au-IDA for AA oxidation. Linearity range has been studied in presence of 250 μM AA obtaining a working range of 60–578 μM for Gr-FMN/Au-IDA electrode and of 60–288 μM with Pt-Gr-FMN/Au-IDA electrode. Limits of detection remain at 18 μM for both electrodes and the repeatability was studied at 177 μM providing 8% and 14% for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA electrodes respectively.This work is supported by the Generalitat Valenciana (Prometeo2013/038) and by the Spanish Ministerio de Economía y Competitividad (MAT2013-42007-P). We also acknowledge partial funding of this work by Ministerio de Economía y Competitividad and the European Regional Development Fund (ERDF) through projectMAT2015-69844-R aswell as by Plan de Ciencia, Tecnología e Innovación 2013–2017 del Principado de Asturias and ERDF (project GRUPIN14-056). A. Abellán-Llobregat also thanks the Generalitat Valenciana for her fellowship and M. Ayán-Varela acknowledges his predoctoral contract (FPI) from Ministerio de Economía y Competitividad

A G-quadruplex aptamer based impedimetric sensor for free lysine and arginine.

This paper describes a label free sensor for the sensitive detection of certain, basic primary amino acids containing free ethyl and methyl amino acids. The control of interfacial electron transfer of a G-quadruplex DNA aptamer, using a Fe(CN)63–/4− redox probe responds rapidly to variations in arginine and lysine concentrations, but not to histidine, using non-labelled, impedance spectroscopy (EIS) detection. Two binding aptamer binding regimes were observed. At the low concentration range (0–0.15 μg/mL), selectivity between lysine and arginine was apparent with limits of detection at approximately 0.5 pMand 1.6 pM respectively. At higher levels of concentrations, 0.15–10 μg/mL, selectivity was limited. The aptamer was immobilised on gold substrates ensuring optimal probe density which was monitored by Atomic Force Microscopy. Initial studies indicate that the relative change in charge transfer resistance (Rct) values can be used as a parameter for monitoring free lysine to arginine ratios and free total lysine and arginine for direct detection of total lysine and arginine in food samples (milk, egg white and yoghurt) in Tris/HCl buffer, demonstrating its potential in many applications

Enhancing clenbuterol immunosensor based on poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotube performance by response surface methodology

Clenbuterol (CLB) is an illegal antibiotic for livestock, which is misused as a growth promoter drug. In this study, an immunosensor modified with poly(3,4-ethylenedioxythiophene) (PEDOT), multi-walled carbon nanotubes (MWCNT) and anti-clenbuterol antibody (Ab) was developed for the detection of CLB. A screen-printed carbon electrode (SPCE) was modified with PEDOT/MWCNT as a sensor platform before immobilizing Ab for specific CLB binding through a competitive-type immunoassay. Free CLB in the sample solution competed with clenbuterol-horseradish peroxide (CLB–HRP) to bind with Ab. A high current signal was obtained after optimization of the electrochemical immunoassay conditions (pH, incubation temperature, antigen (Ag) incubation time and % blocking) using the response surface methodology/central composite design (RSM/CCD). The developed immunosensor is highly reproducible and sensitive with good storage stability, which are necessary for practical application. In real sample application, this immunosensor produces comparable results with liquid chromatography-mass spectrometry; thus, it is useful for CLB screening and monitoring in real meat samples