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.     

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.     

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.     

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.     

Bioapplications of poly(amidoamine) (PAMAM) dendrimers in nanomedicine

Poly(amidoamine) (PAMAM) dendrimers are a novel class of spherical, well-designed branching polymers with interior cavities and abundant terminal groups on the surface which can form stable complexes with drugs, plasmid DNA, oligonucleotides, and antibodies. Amine‐terminated PAMAM dendrimers are able to solubilize different families of hydrophobic drugs, but the cationic charges on dendrimer surface may disturb the cell membrane. Therefore, surface modification by PEGylation, acetylation, glycosylation, and amino acid functionalization is a convenient strategy to neutralize the peripheral amine groups and improve dendrimer biocompatibility. Anticancer agents can be either encapsulated in or conjugated to dendrimer and be delivered to the tumor via enhanced permeability and retention (EPR) effect of the nanoparticle and/or with the help of a targeting moiety such as antibody, peptides, vitamins, and hormones. Biodegradability, non-toxicity, non-immunogenicity, and multifunctionality of PAMAM dendrimer are the key factors which facilitate steady increase of its application in drug delivery, gene transfection, tumor therapy, and diagnostics applications with precision and selectivity. This review deals with the major topics of PAMAM dendrimers including structure, synthesis, toxicity, surface modification, and also possible new applications of these spherical polymers in biomedical fields as dendrimer-based nanomedicine.     

Mechanosorptive creep in nanocellulose materials

The creep behavior of nanocellulose films and aerogels are studied in a dynamic moisture environment, which is crucial to their performance in packaging applications. For these materials, the creep rate under cyclic humidity conditions exceeds any constant humidity creep rate within the cycling range, a phenomenon known as mechanosorptive creep. By varying the sample thickness and relative humidity ramp rate, it is shown that mechanosorptive creep is not significantly affected by the through-thickness moisture gradient. It is also shown that cellulose nanofibril aerogels with high porosity display the same accelerated creep as films. Microstructures larger than the fibril diameter thus appear to be of secondary importance to mechanosorptive creep in nanocellulose materials, suggesting that the governing mechanism is found between molecular scales and the length-scales of the fibril diameter.     

Preparation of bow tie–type methacrylated poly(caprolactone‐co‐lactic acid) scaffolds: effect of collagen modification on cell growth

A branched methacrylated poly(caprolactone‐co‐lactic acid) and methacrylated poly(tetramethylene ether glycol) (PTMG‐IEM) resins were synthesized. ¹H‐NMR spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR) spectroscopy, and gel permeation chromatography confirmed the chemical structures of copolymers. The photoinitiated polymerization of formulation composed of various amounts of methacrylated poly(caprolactone‐co‐lactic acid), PTMG‐IEM, poly(ethylene glycol) diacrylate, water, and photoinitiator were performed. The curing reactions were followed by photo‐DSC (Differential scanning calorimetry). Gel fraction was calculated from the insoluble part and found as ≥93%. Swelling and contact angles were measured, and all increased with the increasing amount of PTMG‐IEM in network formulations. In vitro degradation studies were performed at 37 °C in phosphate‐buffered saline (pH 7.4). Collagen‐modified polymers were also prepared and introduced as a bioactive moiety to modify the polymer to enhance cell affinity. To compare the cell adhesion affinity to the polymer with and without collagen, cell growth experiments were performed. The results showed that collagen improves the cell adhesion onto the polymer surface. With the increasing amount of collagen, cell viability increases 86% (ECV304, p < 0.05) and 83% (3 T3, p < 0.05). Copyright © 2011 John Wiley & Sons, Ltd.     

Numerical and experimental investigation of transverse injection flows

The flow field resulting from a transverse injection through a slot into supersonic flow is numerically simulated by solving Favre-averaged Navier–Stokes equations with κ − ω SST turbulence model with corrections for compressibility and transition. Numerical results are compared to experimental data in terms of surface pressure profiles, boundary layer separation location, transition location, and flow structures at the upstream and downstream of the jet. Results show good agreement with experimental data for a wide range of pressure ratios and transition locations are captured with acceptable accuracy. κ − ω SST model provides quite accurate results for such a complex flow field. Moreover, few experiments involving a sonic round jet injected on a flat plate into high-speed crossflow at Mach 5 are carried out. These experiments are three-dimensional in nature. The effect of pressure ratio on three-dimensional jet interaction dynamics is sought. Jet penetration is found to be a non-linear function of jet to free stream momentum flux ratio.     

Electrochemical DNA biosensor for the determination of benzo[a]pyrene–DNA adducts

The metabolites of the environmental pollutant, benzo[a]pyrene (BaP) are carcinogenic and mutagenic agents. Thus, the determination of additional products (adducts) of the interaction between DNA and BaP, attracts great interest in cancer research.

In this study, the determination of interaction between BaP and calf thymus double-stranded DNA (dsDNA) was performed by using differential pulse voltammetry (DPV) and constant current chronopotentiometric stripping analysis (PSA) in connection with carbon paste electrode (CPE) or glassy carbon electrode (GCE). As a result of interaction of BaP with dsDNA, the signal obtained from the oxidation of guanine decreased and a new adduct signal at a more positive potential appeared. This new peak is attributed to the formation of an adduct from the interaction of guanine with BaP. The chemically prepared anti-7,8,9,10-tetrahydrobenzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) adduct by using iodine oxidation was analyzed and the electrochemical signal of the adduct was observed. When the dsDNA modified GCE was immersed into various concentrations of BaP solution, the oxidation peak of guanine decreased and the adduct peak increased with the increasing BaP concentration. The partition coefficient was also obtained from the peak of BaP with dsDNA. The results revealed that the formation of adducts could be determined by using electrochemical DNA biosensors, which are fast, simple and cost-effective devices. Furthermore, this study promises that the analysis of other important adducts would benefit from the introduction of electrochemical methods.