An investigation of the relationship between BOLD and perfusion signal changes during epileptic generalised spike wave activity

In pathological conditions interpretation of functional magnetic resonance imaging (fMRI) results can be difficult. This is due to a reliance on the assumed coupling between neuronal activity and changes in cerebral blood flow (CBF) and oxygenation. We wanted to investigate the coupling between blood oxygen level dependant contrast (BOLD) and CBF time courses in epilepsy patients with generalised spike wave activity (GSW) to better understand the underlying mechanisms behind the EEG-fMRI signal changes observed, especially in regions of negative BOLD response (NBR). Four patients with frequent GSW were scanned with simultaneous electroencephalographic (EEG)-fMRI with BOLD and arterial spin labeling (ASL) sequences. We examined the relationship between simultaneous CBF and BOLD measurements by looking at the correlation of the two signals in terms of percentage signal change on a voxel-by-voxel basis. This method is not reliant on coincident activation. BOLD and CBF were positively correlated in patients with epilepsy during background EEG activity and GSW. The subject average value of the Delta CBF/Delta BOLD slope lay between +19 and +36 and also showed spatial variation which could indicate areas with altered vascular response. There was not a significant difference between Delta CBF/Delta BOLD during GSW, suggesting that neurovascular coupling to BOLD signal is generally maintained between states and, in particular, within areas of NBR.     

Atomic structure and chemical order in binary Ge–Te and As–Te glasses: A Te K-edge X-ray absorption fine structure spectroscopic study

The nearest-neighbor coordination environments of Te atoms in Ge_xTe_100?x glasses with x = 15 and 20 and in As_xTe_100?x glasses with 40 ? x ? 65 have been studied with Te K-edge EXAFS spectroscopy. The average coordination number of Te atoms in all glasses is found to be ～2.0 and no violation of the 8-N rule is observed. The compositional makeup of the first coordination shell of Te atoms indicates that chemical order is largely preserved in both glass-forming binary systems. Sudden changes in the Te coordination environment and violation of chemical order are observed at the stoichiometric As₄₀Te₆₀ glass implying formation of a constrained network. The compositional dependence of the physical properties in both systems can be correlated to short-range chemical order.     

Lauryl sulfate@magnetic graphene oxide nanosorbent for fast methylene blue recovery from aqueous solutions

Lauryl sulfate is utilized to functionalize magnetic graphene oxide (MGOLS) for fast removal of methylene blue (MB) using batch sorption experiments. The effects of different analytical parameters including medium pH, equilibration time, MGOLS dosage, initial MB concentration and temperature on the % MB removal are investigated. Among different isotherm and kinetic models, the experimental data were best fitted to the Langmuir and pseudo-second-order rate equations. The maximum Langmuir loading capacity reaches 624.42?mg g^?1 for MGOLS under optimal conditions. Sorption kinetic of MGOLS is very fast: Approximately 96% of dye extraction was recorded within the first 2?minutes of this sorption process. The sorption mechanism is proposed and the feasibility, thermic and entropic characteristics were evaluated. Sorption and desorption performances of MGOLS are maintained almost constant over five cycles of sorption/desorption. The results concluded MGOLS as an efficient extractor for fast and feasible recovery of MB from aqueous matrices.     

2D Crystal Engineering of Nanosheets Assembled from Helical Peptide Building Blocks

The successful integration of 2D nanomaterials into functional devices hinges on developing fabrication methods that afford hierarchical control across length scales of the entire assembly. We demonstrate structural control over a class of crystalline 2D nanosheets assembled from collagen triple helices. By lengthening the triple helix unit through sequential additions of Pro‐Hyp‐Gly triads, we achieved sub‐angstrom tuning over the 2D lattice. These subtle changes influence the overall nanosheet size, which can be adjusted across the mesoscale size regime. The internal structure was observed by cryo‐TEM with direct electron detection, which provides real‐space high‐resolution images, in which individual triple helices comprising the lattice can be clearly discerned. These results establish a general strategy for tuning the structural hierarchy of 2D nanomaterials that employ rigid, cylindrical structural units.     

Half-metallicity and onsite Hubbard interaction on d-electronic states: a case study of Fe2NiZ (Z = Al,Ga, Si,Ge) Heusler systems

DFT-based structural optimisations of Fe₂NiZ (Z?=?Al, Ga, Si, Ge) Heusler compounds confirm the stability of these alloys in F-43m phase. While defining the electronic structure, onsite Hubbard approximation scheme for exchange correlations predicted better results than the generalised gradient approximation. Calculated band structure and densities of states together with spin magnetic moments designate the half-metallic character of these alloys. Indirect band gaps, 1.2?eV for Fe₂NiAl, 0.98?eV for Fe₂NiGa, 1.3?eV for Fe₂NiSi and 1.1?eV for Fe₂NiGe in spin-down states are observed. The ferromagnetic spin moments amount to an integral value of 5μB for (Al, Ga) and 6μB for (Si, Ge) systems with a maximum contribution from transition metal atom (Fe). To forecast the possible turnout of the thermopower, Seebeck coefficients, electrical and thermal conductivities are calculated, which directly hints the thermoelectric response of these materials. This study creates a possibility of these alloys in thermoelectrics and spintronics.     

Enhanced antifouling and anticoagulant properties of grafted biomolecule polyethersulfone membranes

Polyethersulfone (PES) has been widely used in membrane technology and used to purify water in water treatments application or as a dialyzer to purify blood in hemodialysis. In this work, PES was chemically modified by separately grafting two biomolecules, 4‐aminobenzenesulfonamide (ABS), and 4‐amino‐N‐(5‐methylisoxazol‐3‐yl)benzenesulfonamide (AMBS), on PES backbone, and these modified membranes were blended to unmodified PES, in 1:1 ratio, in order to obtain PES‐b‐PES‐ABS and PES‐b‐PES‐AMBS membranes. The first aim of this study is to measure the anticoagulant properties of the modified membrane by measuring the activated partial thromboplastin time (APTT) and prothrombin time (PT). The second aim of the study is to evaluate the antifouling properties of the modified PES membranes by examining its antimicrobial activity against two Gram‐negative bacteria, which are Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli); two Gram‐positive bacteria, which are Bacillus subtilis (B. subtilis) and Staphylococcus aureus (S. aureus); and a fungus, which is Candida albicans (C. albicans). The results showed that grafting of ABS and AMBS improved overall the hydrophilicity properties of the modified PES membranes. PES‐b‐PES‐ABS membranes showed better anticoagulant properties with 13 seconds for PT and 38 seconds for APPT, in comparison with the control sample (pure plasma), which showed 12 seconds for PT and 30 seconds for APPT. For antimicrobial tests, both PES‐b‐PES‐ABS and PES‐b‐PES‐AMBS membranes did not show any antibacterial activity, but when zinc oxide (ZnO) nanoparticles were added to the modified PES membranes in concentrations between 3% to 5% w/w, PES‐b‐PES‐ABS‐ZnO (M‐4 and M‐5), and PES‐b‐PES‐AMBS‐ZnO (M‐8 and M‐9) nanocomposite membranes showed antibacterial activity against P. aeruginosa and S. aureus.     

l-Isoleucine-catalyzed Michael Synthesis of N-Alkylsuccinimide Derivatives and Their Antioxidant Activity Assessment

Russian Journal of Organic Chemistry - N-Substituted succinimides having different alkyl groups were prepared by the reaction of N-substituted maleimide with aldehydes. A two-component catalyst...     

Synthesis and in vitro anti-proliferative capabilities of steroidal thiazole and indole derivatives

Derivatives (1–15) of steroidal and indole class were synthesized using different strategies. These compounds were characterized by ¹H NMR spectroscopy and EI-MS, respectively. The synthetic derivatives were examined for their cytotoxic effects on human adenocarcinoma cells (HCT-116) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphometric analysis. The cytotoxic effects of all the compounds were observed after 48 h treatment and it was found that out of fifteen, four compounds 1, 2, 3, and 14 showed inhibitory action on the cancer cells. We have calculated the IC₅₀ values for compounds 1, 2, 3, and 14 which were 22.50 µg/mL, 55.65 µg/mL, 21.35 µg/mL and 58.50 µg/mL, respectively. The compounds 3 (IC₅₀ = 21.35 µg/mL) and 1 (IC₅₀ = 22.50 µg/mL) showed highest inhibitory activities as compared to compounds 2 (IC₅₀ = 55.65 µg/mL) and 14 (IC₅₀ = 58.50 µg/mL). These results suggested that steroidal thiazole and indole derivatives are potent lead molecules having strong anti-cancer proliferative capabilities.     

Ultrasonic assisted improved extraction and dyeing of mordanted silk fabric using neem bark as source of natural colourant

Natural products with therapeutic nature are nowadays warmly welcomed in textiles. Current study is concerned with isolation of tannin from neem bark (Azadirachta indica) and its application onto silk fabric. For improvement in shades, chemical & bio-mordants have been employed at optimal dyeing conditions. It is found that methanolic extract of pH 5 obtained 8 g dye powder after US Treatment for 30 min has given high color strength if used to dye irradiated silk for 65 min at 75 °C. Bio-mordanting using herbal plants has improved the color characteristics as compared to chemical mordants used. ISO standards for color fastness reveal that herbal based bio-mordants have improved the rating from good to excellent as compared to chemical mordants used. It is concluded that US treatment has not only isolate the colorant for neem bark under mild condition but also given excellent characteristic using bio mordants onto silk fabrics.     

Facile route for green synthesis of N-benzylideneaniline over bimetallic reduced graphene oxide: chemical reactivity of 2,3,4-substituted derivatives of aniline

Research on Chemical Intermediates - Mn–Co-decorated reduced graphene oxide (Mn–Co–rGO) was prepared by modified condensation method and characterized through XRD, SEM, EDX, FTIR...