Diffusion-weighted imaging features of brain in obesity

PURPOSE: Obesity is characterized by an altered distribution of body fluid. However, distribution of fluid (extracellular/intracellular) in brain tissues has not been studied in obese subjects yet. The purpose of this study was to detect possible brain diffusion changes especially in satiety and hunger related centers in obese subjects by diffusion weighted imaging (DWI). METHODS: Conventional MRI and DWI of the brain was obtained from 81 obese patients (obese=68, morbid obese=13) and 29 age-matched, nonobese. The apparent diffusion coefficient (ADC) values were calculated in hypothalamus; amygdala; hippocampal gyrus; thalamus; insula; cingulate gyrus; orbitofrontal, dorsomedial and dorsolateral frontal, middle temporal and occipital cortex; cerebellum; midbrain and corpus striatum. RESULTS: The ADC values of hypothalamus, hippocampal gyrus, amygdala, insula, cerebellum and midbrain were significantly increased in patients (n:81) when compared to nonobese subjects. The ADC values of thalamus, hippocampal gyrus, amygdala, orbitofrontal, occipital, dorsolateral and middle temporal cortex, insula and midbrain were significantly increased in morbid obese when compared to nonobese subjects. The ADC values of orbitofrontal and occipital cortex were significantly higher in morbid obese than the values in the obese. The body mass index positively correlated with ADC values of amygdala, insula, orbitofrontal and middle temporal cortex. CONCLUSION: We observed increased ADC values of distinct locations related to satiety and hunger that suggest altered fluid distribution and/or vasogenic edema in obese subjects. Awareness of this abnormalities in brain tissue composition/function in obesity may contribute to better understanding of the underlying mechanisms.     

A Computational Study of the Wallach Rearrangement

Treatment of azoxybenzene and its derivatives with acids is known to result in the Wallach rearrangement, which leads to 2- or4-hydroxyazobenzenes. Starting in the 1960s, experimental findings have lead to the proposal of several mechanisms for this rearrangement. In this work, molecular orbital theory employing the semiempirical AM1 method is used to locate and discuss the energetics of the intermediates and the transition states for this rearrangement. Based on the results of AM1 calculations in vacuum and in solution, the most plausible mechanistic pathways are proposed and discussed.     

Synthesis and structure of 2-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalene)]-5-benzimidazole ethylcarboxylate monohydrate

As part of a program investigating the conformations of potential anticarcinogens and antioxidants, the structure of the title compound C₂₄H₂₈N₂O₂·H₂O is reported. The monohydrate crystallizes in the monoclinic space group P2/c with unit cell parameters a = 16.184(1),b = 7.937(1), c = 16.968(1), = 92.788(7)°, and Z = 4. The benzimidazole and tetrahydrotetramethylnaphthalene ring systems are inclined to one another by approximately 26°. The water molecule plays an important role in the crystal structure by hydrogen bonding to different functional groups of three organic moieties. Additional crystal stabilization is dueto – stacking of benzimidazole rings.     

Variable-Field Hall Effect Analysis of HgCdTe Epilayers with Very Low Doping Density

Ultra-low-doped mercury cadmium telluride (HgCdTe, or MCT) is of significant interest for infrared detectors designed to suppress Auger recombination. Measurement of low doping levels in multi-layered structures is difficult with traditional 4-point Hall effect measurements. Multi-layered Hg_.79Cd_.21Te samples were analyzed using variable magnetic field Hall effect measurements and a multi-carrier fitting procedure. The measurements resolve two distinct carrier species corresponding to surface and/or buffer layer conduction and conduction through the primary low-doped material. High-quality electronic transport is achieved, including the demonstration of an epitaxial layer (x = 0.2195) with n = 1.09 × 10¹⁴ cm^?3 and μ = 275,000 cm²/Vs at 77 K. This technique shows promise as a way to analyze layers with significantly lower doping, and a starting point to understand and advance the development of HgCdTe epilayers with very low doping concentration.     

Solid-phase synthesis of asymmetrically substituted "AB3-type" phthalocyanines

Synthesis of phthalocyanines with asymmetrical substitution on the periphery is often difficult due the problems in purification of the phthalocyanine mixtures obtained. Using a poly(ethylene glycol) (PEG)-based support with a Wang-type linker, we have developed the synthesis of monohydroxylated, oligoethylene glycol substituted phthalocyanines utilizing an amidine-base-promoted phthalonitrile tetramerization reaction. The use of a hydrophilic support allows symmetrical phthalocyanine product formed in solution to be readily and completely removed by washing while leaving the "AB3" product on the support. Acid cleavage with 10% trifluoroacetic acid provides the pure unsymmetrically substituted Pc. This method was applied to several metallo Pcs. Additionally, methods to avoid premature reactions on-resin that give A2B2 products are provided.     

Determination of Some Heavy Metal Ions with a Carbon Paste Electrode Modified by Poly(glycidylmethacrylate‐methylmethacrylate‐divinylbenzene) Microspheres Functionalized by 2‐Aminothiazole

A carbon paste electrode modified with 2‐aminothiazole functionalized poly(glycidylmethacrylate‐methylmethacrylate‐divinylbenzene) microspheres was used for trace determination of mercury, copper and lead ions. After the open‐circuit accumulation of the heavy metal ions onto the electrode, the sensitive anodic stripping peaks were obtained by square wave anodic stripping voltammetry (SWASV)). Many parameters such as the composition of the paste, pH, preconcentration time, effective potential scan rate and stirring rate influence the response of the measurement. The procedures were optimized for most sensitive and reliable determinations of the desired species. For a 10‐min preconcentration time in synthetic solutions at optimum instrumental and experimental conditions, the detection limit (LOD) was 12.3, 2.8 and 4.5 μg L^?1 for mercury, copper and lead, respectively. The limits of detection may be enhanced by increasing the preconcentration time. For example, LOD of mercury and copper was 4.9 and 1.0 μg L^?1 for fifteen minutes preconcentration time. The sensitivity may also considered to be increased by using a more suitable electrode composition targeting the more conductive electrode with lesser amount of modified polymer for sub‐μg L^?1 levels of heavy metal ions. The optimized method was successfully applied to the determination of copper in tap water and waste water samples by means of standard addition procedure. The copper content found was comparable with the certified concentration of the waste water sample. The calibration plots for mercury and lead spiked real samples were also drawn.     

Synthesis and characterization of azo-linked Schiff bases and their nickel(II), copper(II), and zinc(II) complexes

Azo compounds were prepared by coupling of benzenediazonium chloride ions with 1-amino-2-hydroxy-4-naphthalene sulfonic acid under alkaline conditions, and Schiff bases, L_1–3 were then obtained by the condensation of 1-amino-2-hydroxy-3-(phenylazo)-4-naphthalene sulfonic acid, 1-amino-2-hydroxy-3-(4-ethylphenylazo)-4-naphthalene sulfonic acid, and 1-amino-2-hydroxy-3-(4-nitrophenylazo)-4-naphthalene sulfonic acid with salicylaldehyde. New copper(II), nickel(II), and zinc(II) complexes of the Schiff base ligands were also prepared and characterized by spectroscopic methods, magnetic measurements, elemental, and thermogravimetric analysis.     

Poly(vinylferrocenium) coated disposable pencil graphite electrode for DNA hybridization

Poly(vinylferrocenium) (PVF⁺) modified electrode was developed in this study for the electrochemical sensing of DNA based on the oxidation signals of polymer, adenine and guanine. Experimental parameters, such as; polymeric film thickness, DNA immobilization time and DNA concentration were examined in order to obtain more sensitive and selective electrochemical signals. After optimization studies, DNA hybridization was investigated.     

Investigation of novel monopodal and dipodal oxy-Schiff base triazine from cyanuric chloride: Structural and antimicrobial studies

During the last few years, the potential of s-triazine derivatives in agrochemical and medicinal properties have been subjected to investigation. s-Triazine derivatives have received great attention due to their significant antimicrobial, antibacterial, antifungal, anti-HIV, anticancer, and a wide array of other biological activities. The present study reported a method for achieving Dipodal systems formed by reaction 2,4,6-trichloro-1,3,5-triazine and 4-hydroxybenzaldehyde, 2-aminophenol. Herein, we reported the synthesis of a dialdehyde and its Schiff base as a new template. The reaction of cyanuric chloride with 1 equiv. methanol and 2 equiv. of p-hydroxybenzaldehyde gave the desired dialdehyde. The dialdehyde was then reacted with 2-aminophenolto afford the corresponding multidirectional oxy-Schiff base triazines. The structures of the compounds were identified by FT-IR,¹H-NMR and elemental analysis. Their antimicrobial activities were performed by using the broth microdilution method in DMSO: Phosphate Buffered Saline (PBS) against eight bacteria strain and one yeast strain. The results of the test were compared with gentamicin. It has been determined that 2,4-Bis(2-hydroxyphenylimino-4'-formylphenoxy)-6-methoxy-1,3,5-triazine (3) Padalkar, V. S., Gupta, V. D., Phatangare, K. R., Patil, V. S., Umape, P. G., Sekar, N. J. (2014) Saudi. Chem. Soc., 18, 262–268.[Crossref], [Web of Science ®] , [Google Scholar] (2DP2AF) and 2-(2-hydroxyphenylimino-4'-formylphenoxy)-4-(4'-formylphenoxy)-6-methoxy-1,3,5-triazine (2) Raval, J. P., Rai, A. R., Patel, N. H., Patel, H. V., Patel, P. S. (2009) Int. J. Chem. Tech. Res., 1, 616–620. [Google Scholar] (1DP2AF) have significant antibacterial and antifungal activity against Enterococcus faecalis and Candida albicans and these effects were close to the control antibiotic used. Ent. faecalis was the most sensitive strain against both two tested chemicals. It was determined that our chemicals have similar antifungal capacity when compared to gentamicin.