Fabrication and characterization of calix[4]arene Langmuir–Blodgett thin film for gas sensing applications

Microwave irradiation has been found to be a highly efficient method for etherification of p-tert-butylcalix[4]arene with alkyl bromides or ditosylate. The corresponding products were obtained as a pure form in modest yield within short reaction time when the reactions were performed under microwave irradiation.     

Hemoglobinopathy control program in Turkey

Hemoglobinopathies are a very important health problem in Turkey. To date many studies have been performed but there has been no national hemoglobinopathy control program (HCP). After the Turkish National Hemoglobinopathy Council (TNHC) was created all centers, foundations, and associations were combined into one organization controlled by the Ministry of Health (MOH). The MOH and the TNHC have started to register the results of the screening of 377,339 healthy subjects from 16 different cities and the recorded average frequency of the beta-thalassemia trait was 4.3%. The highest prevalence of thebeta-thalassemia trait (13.1%) was found in the Antalya region and of the HbS trait (10%) in the Cukurova region. Next, written regulations for the Fight against Hereditary Blood Disease were published especially for preventing and treating hemoglobinopathies. The MOH and the TNHC selected 33 provinces situated in the Thrace, Marmara, Aegean, Mediterranean and South Eastern regions with a high birth prevalence of severe hemoglobinopathies. The hemoglobinopathy scientific committee was set up, a guidebook was published and a national HCP was started in these high-risk provinces.     

Spun films of perylene diimide derivative for the detection of organic vapors with host–guest principle

The optical characterization and chemical vapor sensing properties of 1,7-dibromo-N,N′-(bicyclohexyl)-3,4:9,10-perylene diimide thin film against to organic vapors were discussed in this study by using spin coating, UV–Vis spectroscopy, atomic force microscopy, surface plasmon resonance (SPR) and Quartz Crystal Microbalance (QCM) techniques. The perylene diimide thin films were fabricated with a refractive index values from 1.55 to 1.60 and thicknesses in the range between 15.80 and 26.32 nm using different spin speeds from 1000 to 5000 rpm. In this study, perylene diimide thin film sensor was exposed to dichloromethane, chloroform, carbon tetrachloride, tetrahydrofuran and ethyl acetate vapors by using both SPR and QCM techniques. Also, the swelling behaviors of the perylene diimide thin films prepared at different spin speeds were investigated with respect to dichloromethane vapor at the room temperature by using SPR data. Diffusion coefficients were found to be 11.34?×?10^?17 (1000 rpm), 2.56?×?10^?17 (3000 rpm) and 0.38?×?10^?17 cm² s^?1 (5000 rpm) for dichloromethane vapor by using the Fick’s law of diffusion. It might be proposed that perylene diimide thin film optical chemical sensor element has a good sensitivity and selectivity for the dichloromethane vapor at room temperature.     

-Difference sequence spaces of fuzzy numbers

In this paper, using the difference operator of order m and an Orlicz function, we introduce and examine some classes of sequences of fuzzy numbers. We give the relations between the strongly Cesàro type convergence and statistical convergence in these spaces. Furthermore, we study some of their properties like completeness, solidity, symmetricity, etc. We also give some inclusion relations related to these classes.     

Lipid-lowering effects of ethyl 2-phenacyl-3-aryl-1H-pyrrole- 4-carboxylates in rodents

A series of substituted 2-phenacyl-3-phenyl-1H-pyrrole-4-carboxylates were prepared from substituted acetophenones in 6 steps. The final condensations between a chloroenal and an aminoketone were carried out under neutral conditions in parallel to yield the series listed below. Selected pyrrole derivatives proved to be potent hypolipidemic agents lowering serum triglyceride concentrations in CF-1 male mice after 14 days of I.P. administration. One agent orally lowered serum cholesterol in Sprague-Dawley male rats at 2mg/kg/day after 14 days. The agents demonstrated a lowering of mouse serum LDL- cholesterol levels and selected compounds showed an elevation of serum HDL-cholesterol levels. The cholesterol concentrations in the liver were raised while the cholesterol and triglyceride contents of the aorta were significantly lowered by the selected trisubstituted pyrrole.     

Demonstration of a plasmonic thermocycler for the amplification of human androgen receptor DNA

A plasmonic heating method for the polymerase chain reaction is demonstrated by the amplification of a section of the human androgen receptor gene. The thermocycler has a simple low-cost design, demonstrates excellent temperature stability and represents the first practical demonstration of plasmonic thermocycling.     

Photoluminescence and Coordination Behaviour of Lanthanide Complexes of Tris (Aminomethyl)Ethane-5-Oxine in Aqueous Solution

Photophysical properties of a multidentate tripodal ligand, 5,5′-(2-(((8-hydroxyquinolin-5-yl) methylamino)methyl)-2-methylpropane-1,3-diyl) bis (azanediyl)bis (methylene)diquinolin-8-ol, (TAME5OX), with La³⁺ and Er³⁺ ions have been examined for photonics applications. The change in behavior in electronic spectra of these complexes reveals the use of TAME5OX as a sensitive optical pH based sensor to detect Ln³⁺ ions whereas indication of strong green fluorescence allows simultaneous sensing within the visible region in competitive medium. The intense fluorescence intermittently gets quenched under acidic and basic conditions due to photoinduced intramolecular electron transfer from the excited 8-hydroxyquinoline (8-HQ) moiety to the metal ion. This renders these compounds the OFF-ON-OFF type of pH-dependent fluorescent sensor. The thermodynamic stability and coordination behaviour of the chelator with the said lanthanide ions have also been probed by potentiometric, UV ? visible and fluorescence spectrophotometric method. TAME5OX forms protonated complex [Ln (H₄L)]⁴⁺ below pH ~4.0 which sequentially deprotonates through one proton process with increase of pH. The stability constants of neutral complexes have been determined to be in the range log β₁₁₀ = 32–34 and pLn in the range of 14–20, indicating TAME5OX is a good synthetic lanthanide chelator. Theoretical spectra were also calculated by ZINDO/s methodology at single excitations (CIS) level on PM7 as sparkle energy-minimized geometries.     

Uptake of pyrene by NaCl, NaNO3, and MgCl2 aerosol particles

Photoelectric charging experiments measure heterogeneous uptake coefficients for pyrene on model marine aerosol particles, including NaCl, NaNO(3), and MgCl(2). The analysis employs a multilayer kinetic model that contains adsorption and desorption rate constants for the bare aerosol surface and for pyrene-coated surfaces. First coating the aerosol particles with a pyrene layer and following the desorption using both t-DMA and photoelectric charging yields the desorption rate constants. Separate experiments monitor the increase in surface coverage of initially bare aerosol particles after exposure to pyrene vapor in a sliding-injector flow tube. Analyzing these data using the multilayer model constrained by the measured desorption rate constants yields the adsorption rate constants. The calculated initial heterogeneous uptake coefficient, γ(0)(295 K), is 1.1 × 10(-3) for NaCl, 6.6 × 10(-4) for NaNO(3), and 6.0 × 10(-4) for MgCl(2). The results suggest that a free energy barrier controls the uptake rate rather than kinematics.     

Calix[4]arene-triazine conjugate intermediate: optical properties and gas sensing responses against aromatic hydrocarbons in Langmuir–Blodgett films

Research on Chemical Intermediates - The detection of organic vapors by chemically based sensors was achieved with macromolecules having convenient molecular cavities. Addressed herein, a...     

A novel triazine‒bearing calix[4]arene: Design,synthesis and gas sensing affinity for volatile organic compounds

A novel triazine-calix[4]arene conjugate was designed and synthesized with the aim to study gas sensing against volatile organic compounds (VOCs) such as dichloromethane, chloroform and carbon tetrachloride. This novel compound was fully characterized by spectroscopic techniques such as FTIR, ¹H and ¹³C NMR along with HRMS and BET analysis. The triazine based calix[4]arene organic materials were fabricated onto quartz glasses and quartz crystal substrates to form a thin film chemical sensor element by using Langmuir-Blodgett (LB) technique. Quartz Crystal Microbalance, UV–Visible Spectroscopy, Atomic Force Microscopy and Scanning Electron Microscopy techniques were employed to characterize all these LB thin film layers. Fick's Equations were used for analyzing the swelling process of LB thin film sensor and diffusion coefficient values of organic vapours for swelling were obtained. The initial experiments have revealed that new triazine appended calix[4]arene derivative exhibited an effective chemical gas sensor characteristic with a large response to dichloromethane vapour.