A selective optical sensor for beryllium determination based on incorporating of 1,8-dihydroxyanthrone in a poly (vinyl chloride) membrane.

A new optical sensor was fabricated for determination of beryllium ions. The optode membrane was prepared by incorporation of 1,8-dihydroxyanthrone and sodium tetraphenylborate (NaTPB) in a plasticized poly (vinyl chloride) membrane containing ortho-nitrophenyl octyl ether (o-NPOE) as a plasticizer. Color of the sensing membrane in contact with Be(2+) ions at pH 10.

Used gold nano-particles as an on/off switch for response of a potentiometric sensor to Al(III) or Cu(II) metal ions.

The potentiometric response of a carbon paste electrode modified with silica sol-gel and mercaptosuccinic acid (MSA) in the presence and absence of gold nano-particles was studied. The results showed that the electrode with gold nano-particles was responded to Al(3+) ions as a hard metal ion. On the other hand, the electrode without gold nano-particles was responded to copper ions as a soft metal ion.

Probing ¹³C chemical shielding tensors in cryptolepine and two bromo-substituted analogs for antiplasmodial activity.

Density functional theory calculations were applied to investigate (13)C chemical shielding tensors in cryptolepine and its bromo-substituted analogs, 2-bromocryptolepine and 2,7-dibromocryptolepine. The fact that bromo-substituted cryptolepine shows higher antiplasmodial activity than cryptolepine raises the question of whether this effect can be related to the electronic properties around carbon atoms. The results show that changes to the principal components of the shielding tensors upon substitution are significant.

Application of RNA interference in treating human diseases.

Gene silencing can occur either through repression of transcription, termed transcriptional gene silencing (TGS), or through translation repression andmRNA degradation, termed posttranscriptional gene silencing (PTGS). PTGS results from sequence-specific mRNA degradation in the cytoplasm without dramatic changes in transcription of corresponding gene in nucleus. Both TGS and PTGS are used to regulate endogenous genes.

Synthesis, X-ray crystallography characterization, vibrational spectroscopic, molecular electrostatic potential maps, thermodynamic properties studies of N,N'-di(p-thiazole)formamidine.

In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of N,N'-di(p-thiazole)formamidine (DpTF). DpTF has been synthesized and characterized by elemental analysis, FT-IR, FT-Raman, 1H NMR, 13C NMR spectroscopy and X-ray single crystal diffraction. The FT-IR and FT-Raman spectra of DpTF were recorded in the solid phase.

Multi-walled carbon nanotubes-ionic liquid-carbon paste electrode as a super selectivity sensor: application to potentiometric monitoring of mercury ion(II).

In this article a super selectivity potentiometric methodology, using an ion-selective electrode, for determination of mercury ion(II) in aqueous solution was investigated. For modification of the electrode a room temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIM·BF(4)), was applied as a super conductive binder, and Multi-walled carbon nanotubes (MWCNTs) was used in the composition of the carbon paste to improve conductivity and transduction of chemical signal to electrical signal. Moreover, incorporation of 1-(2-ethoxyphenyl)-3-(3-nitrophenyl)triazene (ENTZ) as an ionophore to this composition caused to significantly enhanced selectivity toward Hg(II) ions over a wide concentration range of 1.

Comparative studies of mercapto thiadiazoles self-assembled on gold nanoparticle as ionophores for Cu(II) carbon paste sensors.

Comparative studies of the potentiometric behavior of three mercapto compounds [2-((5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl)phenol] (MTMP), [5-(2-methoxy benzylidene amino)-1,3,4-thiadiazole-2-thiol] (MBYT) and [5-(pyridin-2-ylmethyleneamino)-1,3,4-thiadiazole-2-thiol] (PYTT) self-assembled on gold nanoparticles (GNPs) as ionophores in carbon paste electrodes (CPEs) have been made. These mercapto thiadiazole compounds were self-assembled onto gold nanoparticles and then incorporated within carbon paste electrode. The self-assembled ionophores exhibit a high selectivity for copper ion (Cu(2+)), in which the sulfur and nitrogen atoms in their structure play a role as the effective coordination donor site for the copper ion.

X-ray crystallography characterization, vibrational spectroscopy, NMR spectra and quantum chemical DFT/HF study of N,N'-di(2-methoxyphenyl)formamidine.

The title compound, N,N'-di(2-methoxyphenyl)formamidine (DMPF) was synthesized and characterized by FT-IR, FT-Raman, (1)H NMR, (13)C NMR spectroscopy and X-ray single crystal diffraction. The results show that the compound crystallizes in an orthorhombic system, with space group of Pbca and eight molecules in the unit cell. The unit cell parameters are: a=11.

Dose evaluation and measurement of radon concentration in some drinking water sources of the Ramsar region in Iran.

Ramsar is one of the highest background radiation areas in the world, whose natural radioactivity is due to (238)U natural series and its decay products, especially (226)Ra and (220)Rn, which have been brought to the surface by water of hot springs. In this study, radon concentration in 14 drinking water sources of the Ramsar region has been measured with the PRASSI system. The results show all of the water supplies have radon concentration greater than 10kBq/m(3) as normal level.

Air kerma strength characterization of a GZP6 Cobalt-60 brachytherapy source.

Background: Task group number 40 (TG-40) of the American Association of Physicists in Medicine (AAPM) has recommended calibration of any brachytherapy source before its clinical use. GZP6 afterloading brachytherapy unit is a (60)Co high dose rate (HDR) system recently being used in some of the Iranian radiotherapy centers.

Aim: In this study air kerma strength (AKS) of (60)Co source number three of this unit was estimated by Monte Carlo simulation and in air measurements.

Transcriptional down regulation of hTERT and senescence induction in HepG2 cells by chelidonine.

Aim: To investigate the potential effects of chelidonine, the main alkaloid of Chelidonium majus, on telomerase activity and its regulation in HepG2 cells.

Methods: Cytotoxicity of chelidonine for HepG2 cells was determined by neutral red assay. A modified polymerase chain reaction (PCR)-based telomerase repeat amplification protocol was used to estimate relative telomerase activity in chelidonine-treated cells in comparison with the untreated control cells.

Voltammetric determination of some anti-malarial drugs using a carbon paste electrode modified with Cu(OH)2 nano-wire.

A sensitive electroanalytical methodology for the determination of chloroquine and primaquine using differential pulse voltammetry (DPV) at a Cu(OH)2 nano-wire-modified carbon paste electrode is presented. The cyclic voltammetric and DPV pulse voltammetric techniques are compared. The effects of scan rate and pH on current were investigated and an optimal scan rate of 50 mV s(-1) and a pH 5.

Theoretical study of internal conversion decay rates associated with the three lowest singlet electronic states in pyrazine.

The general expressions we recently derived for calculating internal conversion decay rate constants between two adiabatic and between two diabatic displaced-distorted-rotated harmonic potential energy surfaces (including all vibrational modes) are now applied to determine the decay rate constants of 1B(2u)(pi pi*)-->1B(3u)(n pi*), 1B(2u)(pi pi*)-->1A(g), and 1B(3u)(n pi*)-->1A(g) internal conversions in pyrazine molecule. The minimal models with respect to the number and the types of vibrational modes are investigated for these processes. An exact expression for the adiabatic vibrational frequencies of the coupling modes in terms of interstate coupling constants and the parameters determining the diabatic potential energy surfaces are also derived.

Liquid phase microextraction and ultratrace determination of cadmium by modified graphite furnace atomic absorption spectrometry.

A powerful microextraction technique was used for determination of cadmium in water samples using liquid phase microextraction (LPME) followed by graphite furnace atomic absorption spectrometry (GF-AAS). In a preconcentration step, cadmium was extracted from a 2 ml of its aqueous sample in the pH 7 as 5,7-dibromoquinoline-8-ol (DBQ) complex into a 4 microl drop of benzyl alcohol. After extraction, the micro drop was retracted and directly transferred into a graphite tube modified by [W.

Hydroxonium hydrate tris(2,4,6-triamino-1,3,5-triazin-1-ium) bis[bis(pyridine-2,6-dicarboxylato)manganate(II/III)] hydroxide pyridine-2,6-dicarboxylic acid solvate pentahydrate.

For charge balance in the title compound, (H(5)O(2))(C(3)H(7)N(6))(3)[Mn(C(7)H(3)NO(4))(2)](2)(OH).C(7)H(5)NO(4).5H(2)O, it is assumed that the metal atom site is disordered Mn(II)/Mn(III), probably due to partial air oxidation of the starting Mn(II) species.

Modelling the elements of country vulnerability to earthquake disasters.

Earthquakes have probably been the most deadly form of natural disaster in the past century. Diversity of earthquake specifications in terms of magnitude, intensity and frequency at the semicontinental scale has initiated various kinds of disasters at a regional scale. Additionally, diverse characteristics of countries in terms of population size, disaster preparedness, economic strength and building construction development often causes an earthquake of a certain characteristic to have different impacts on the affected region.

Prevalence of internet addiction and comparison of internet addicts and non-addicts in Iranian high schools.

In this study, 1968 high-school students were selected randomly through clustering, who responded to the Persian version of four measures: the Internet Addiction Test (IAT), UCLA Loneliness Scale, Rosenberg Self-Esteem Scale, and Matson Evaluation of Social Skills. Of the sample, 977 students were Internet users, who were classified into 37 Internet addicts, 304 possible Internet addicts, and 636 moderate users. Since possible addicts, moderate users, and nonusers can all be considered nonaddicts, to make a comprehensive and controlled comparison between addicts and nonaddicts, 37 possible addicts, 37 moderate users and 37 nonusers were matched with the Internet addicts.

Growth and some physiological parameters of four sugar beet (Beta vulgaris l.) cultivars as affected by salinity.

The comparative responses of certain biochemical and physiological characteristics to salinity were studied in 4 cultivars of sugar beet (Beta vulgaris L.) plants. Eight weeks old plants were treated with NaCl at 0, 25 and 50 mM in nutrient solutions.

Reliability of a computer-aided color-coded video-based system for clinical assessment of the foot.

Unlabelled: There is a need for a user-friendly system that can provide quick and reliable assessment of foot disorders. The study described in this report was undertaken to determine the inter-rater and intra-rater reliability of a computer-aided, color-coded, video-based system developed for the assessment of foot alignment in patients with and without pes cavus deformity. Initially, 15 pedal angles were repetitively measured 7 times on 6 color-coded images of both feet, in 20 healthy adults.

Copper(II) modified carbon paste electrodes based on self-assembled mercapto compounds-gold-nanoparticle.

Three mercapto compounds [2-mercapto-5-(1-methyl-5-nitroimidazole-2-yl)-1,3,4-thiadiazole] (MMNIT), [2-mercapto-5-(5-nitrofuran-2-yl)-1,3,4-thiadiazole] (MNFT) and [2-mercapto-5-(5-nitrothiophen-2-yl)-1,3,4-thidiazole] (MNTT) were used for self-assembled-gold nanoparticle (SAGNP) modified carbon paste electrodes. The electrodes were applied as indicator electrodes for potentiometric determination of Cu(II) ion. The prepared electrodes exhibit a Nernstian slope of 31.

Bracing has no effect on standing balance in females with adolescent idiopathic scoliosis.

Background: Since trunk morphology and curve types were reported to affect standing in adolescent idiopathic scoliosis (AIS), it is reasonable to assume that bracing could perturb standing balance in this population. The objective here was to use time- and frequency-domain analyses to test if the Boston brace affects balance in AIS.

Material/methods: Fifteen AIS girls were fitted with a Boston brace.

Separation and preconcentration of ultra trace amounts of beryllium in water samples using mixed micelle-mediated extraction and determination by inductively coupled plasma-atomic emission spectrometry.

In the present study a cloud point extraction process using mixed micelle of the cationic surfactant cetyl-pyridinium chloride (CPC) and non-ionic surfactant Triton X-114 for extraction of beryllium from aqueous solutions is developed. The extraction of analyte from aqueous samples was performed in the presence of 1,8-dihydroxyanthrone as chelating agent in buffer media of pH 9.5.

Poly[ethyl-enediaminium [di-μ-aqua-(μ(6)-benzene-1,2,4,5-tetra-carboxyl-ato-κO,O:O,O:O:O,O:O:O,O)dithallium(I)]].

The title compound, {(C(2)H(10)N(2))[Tl(2)(C(10)H(2)O(8))(H(2)O)(2))]}(n), was prepared using (enH(2))(2)(btc)·2H(2)O and thallium(I) nitrate (en = ethyl-enediamine and btcH(4) = benzene-1,2,4,5-tetra-carboxylic acid). The enH(2) cation and btc ligand are each located on an inversion centre. The Tl(I) atom is seven-coordinated by three btc ligands and two water mol-ecules in an irregular geometry due to the stereochemically active lone pair on the Tl centre.

2,6-Diamino-pyridinium bis-(4-hydroxy-pyridine-2,6-dicarboxyl-ato-κO,N,O)ferrate(III) dihydrate.

The reaction of iron(II) sulfate hepta-hydrate with the proton-transfer compound (pydaH)(hypydcH) (pyda = pyridine-2,6-diamine; hypydcH(2) = 4-hydroxy-pyridine-2,6-dicarboxylic acid) in an aqueous solution led to the formation of the title compound, (C(5)H(8)N(3))[Fe(C(7)H(3)NO(5))(2)]·2H(2)O. The anion is a six-coordinated complex with a distorted octa-hedral geometry around the Fe(III) atom. Extensive inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, involving the complex anion, (pydaH)(+) counter-ion and two uncoordinated water mol-ecules, and π-π [centroid-to-centroid distance 3.

Hemipiperazinediium bis-(pyridine-2,6-dicarboxyl-ato-κO,N,O')gallate(III) pyridine-2,6-dicarboxylic acid dihydrate.

The asymmetric unit of the title compound, (C(4)H(12)N(2))(0.5)[Ga(pydc)(2)]·pydcH(2)·2H(2)O, where pydcH(2) is pyridine-2,6-dicarboxylic acid, C(7)H(5)NO(4), contains one half of a centrosymmetric piperazinediium dication, one anion, one uncoord-inated pydcH(2) mol-ecule and two uncoordinated water mol-ecules, one of which is disordered over two sites in a 1:1 ratio. In the anion, the Ga(III) ion is coordinated by four O atoms [Ga-O = 1.