Multidirectional ECG Coherent Optimal Timing of Defibrillation Shocks

A method for of delivering a defibrillation shock to a heart at an optimal time to stop ventricular fibrillation which involves obtaining an electrocardiogram of a heart in at least two directions, determining a time-coherency of the electrocardiogram based upon each of the at least two directions, and computing a tracking function from the time-coherency. An optimal time to apply a defibrillation shock to the heart is determined by locating a local maximum on the tracking function. The method utilizes spacia characteristics of the ventricular fibrillation. The method can be incorporated into implantable cardioverter defibrillators utilizing existing hardware technology

FT-IR characterization of antimicrobial hybrid materials through sol-gel synthesis

Silica/polycaprolactone and titania/polycaprolactone hybrid organic/inorganic amorphous composites were prepared via a sol-gel method starting from a multi-element solution containing tetramethyl orthosilicate (TMOS) or titanium butoxide (TBT), polycaprolactone (PCL), water and methylethylketone (MEK). The molecular structure of the crosslinked network was based on the presence of the hydrogen bonds between organic/inorganic elements as confirmed by Fourier Transform Infra-Red (FT-IR) analysis. In particular, the structure of crosslinked network was realized by hydrogen bonds between the X-OH (X = Si or Ti) group (H donator) in the sol-gel intermediate species and ester groups (H-acceptors) in the repeating units of the polymer. The morphology of the hybrid materials; pore size distribution, elemental homogeneity and surface features, was studied by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and by atomic force microscopy (AFM). The bioactivity of the synthesized hybrid materials was confirmed by observing the formation of a layer of hydroxyapatite (HAP) on the surface of the samples soaked in a simulated body fluid. The antimicrobial behavior of synthetized hybrids was also assessed against Escherichia coli bacteria. In conclusion, the prepared hybrid materials are proposed for use as future bone implants

The intramolecular aldol condensation of 3-oxocyclohexaneacetaldehydes: A useful tool in the synthesis of natural products

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Impact of environmental factors on stilbene biosynthesis

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds

Excitonic coupling dominates the homogeneous photoluminescence excitation linewidth in semicrystalline polymeric semiconductors

We measure the homogeneous excitation linewidth of regioregular poly(3-hexylthiophene), a model semicrystalline polymeric semiconductor, by means of two-dimensional coherent photoluminescence excitation spectroscopy. At a temperature of 8\,K, we find a linewidth that is always $\gtrsim 110$\,meV full-width-at-half-maximum, which is a significant fraction of the total linewidth. It displays a spectral dependence and is minimum near the 0--0 origin peak. We interpret this spectral dependence of the homogeneous excitation linewidth within the context of a weakly coupled aggregate model.Comment: 13 pages, 4 figures, Supplementary Materia

Partial Hydrogenation of Soybean and Waste Cooking Oil Biodiesel over Recyclable-Polymer-Supported Pd and Ni Nanoparticles

Biodiesel obtained through the transesterification in methanol of vegetable oils, such as soybean oil (SO) and waste cooking oil (WCO), cannot be used as a biofuel for automotive applications due to the presence of polyunsaturated fatty esters, which have a detrimental effect on oxidation stability (OS). A method of upgrading this material is the catalytic partial hydrogenation of the fatty acid methyl ester (FAME) mixture. The target molecule of the partial hydrogenation reaction is monounsaturated methyl oleate (C18:1), which represents a good compromise between OS and the cold filter plugging point (CFPP) value, which becomes too high if the biodiesel consists of unsaturated fatty esters only. In the present work, polymer-supported palladium (Pd-pol) and nickel (Ni-pol) nanoparticles were separately tested as catalysts for upgrading SO and WCO biodiesels under mild conditions (room temperature for Pd-pol and T = 100◦ C for Ni-pol) using dihydrogen (p = 10 bar) as the reductant. Both catalysts were obtained through co-polymerization of the metal containing monomer M(AAEMA)2 (M = Pd, Ni; AEEMA− = deprotonated form of 2-(acetoacetoxy)ethyl methacrylate)) with co-monomers (ethyl methacrylate for Pd and N,N-dimethylacrilamide for Ni) and cross-linkers (ethylene glycol dimethacrylate for Pd and N,N’-methylene bis-acrylamide for Ni), followed by reduction. The Pd-pol system became very active in the hydrogenation of C=C double bonds, but poorly selective towards the desirable C18:1 product. The Ni-pol catalyst was less active than Pd-pol, but very selective towards the mono-unsaturated product. Recyclability tests demonstrated that the Ni-based system retained its activity and selectivity with both the SO and WCO substrates for at least five subsequent runs, thus representing an opportunity for waste biomass valorization

Tree-ring–based summer mean temperature variations in the Adamello–Presanella Group (Italian Central Alps), 1610–2008 AD

Abstract. Climate records from remote mountain sites and for century-long periods are usually lacking for most continents and also for the European Alps. However, detailed reconstructions of climate parameters for pre-instrumental periods in mountain areas, suffering of glacial retreat caused by recent global warming, are needed in the view of a better comprehension of the environmental dynamics. We present here the first annually-resolved reconstruction of summer (JJA) mean temperature for the Adamello–Presanella Group (Central European Alps), one of the most glaciated mountain groups of the Italian Central Alps. The reconstruction has been based on four larch tree-ring width chronologies derived from living trees sampled in four valleys surrounding the Group. The reconstruction spans from 1610 to 2008 and the statistical verification of the reconstruction demonstrates the positive skill of the tree-ring dataset in tracking summer temperature variability also in the recent period

Synthesis of Cu-containing Diopside through a One-Step Crystallization

The incorporation of copper into pyroxene structure was investigated through the melt quenching technique and one-step crystallization procedure. Two series of glasses have been studied, one set with Ca=Mg and another set with Ca>Mg in diopside formula Cux(Ca Mg)2-xSi2O6. The glasses were nucleated by TiO2, Cr2O3, or CaF2 additions as nucleating agents to variably control the phases produced. X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the obtained samples. The heat treatment studied at 700, 800, 900 and 1000 °C for 2 h produced green and dark green glasses based on Cu-containing diopside. Various crystalline wollastonite, cuprite, tenorite, cristobalite, quartz, and fluorite phases were developed with different ratios combined with diopside formation depending on the heat treatment and nucleating agents used. As the heat treatment increased in temperature, the crystallized fraction increased with the development of nano-aggregates and the observed reticulated textures confirmed a radical change in the euhedral crystals. This emphasizes that the Cu-containing diopside can be created by a facile one step process. These compositions may find some applications in biological and optical fields

Design of inorganic polymer mortar from ferricalsialic and calsialic slags for indoor humidity control

Amorphous silica and alumina of metakaolin are used to adjust the bulk composition of black (BSS) and white (WSS) steel slag to prepare alkali-activated (AAS) mortars consolidated at room temperature. The mix-design also includes also the addition of semi-crystalline matrix of river sand to the metakaolin/steel powders. The results showed that high strength of the steel slag/metakaolin mortars can be achieved with the geopolymerization process which was particularly affected by the metallic iron present into the steel slag. The corrosion of the Fe particles was found to be responsible for porosity in the range between 0.1 and 10 μm. This class of porosity dominated (~31 vol %) the pore network of B compared to W samples (~16 vol %). However, W series remained with the higher cumulative pore volume (0.18 mL/g) compared to B series, with 0.12 mL/g. The maximum flexural strength was 6.89 and 8.51 MPa for the W and B series, respectively. The fracture surface ESEM observations of AAS showed large grains covered with the matrix assuming the good adhesion bonds between the gel-like geopolymer structure mixed with alkali activated steel slag and the residual unreacted portion. The correlation between the metallic iron/Fe oxides content, the pore network development, the strength and microstructure suggested the steel slag's significant action into the strengthening mechanism of consolidated products. These products also showed an interesting adsorption/desorption behavior that suggested their use as coating material to maintain the stability of the indoor relative humidity

Recycling of Waste Corundum Abrasive Powder in Mk-Based Geopolymers

Recycling corundum abrasive powder in metakaolin-based geopolymer formulations is proposed to reduce the amount of waste to be treated or disposed of in landfills, allowing to decrease ecological damage as well as to reduce transport costs for removal. The addition of waste corundum, as an important source of Al2O3, has proved to increase the slightly ionic conductivity of the leachate solution obtained after immersion in water of samples at 28 d of curing at room temperature. With the same curing conditions, the geopolymerization process has not been disturbed as evidenced by the FT-IR peak shift and XRD patterns. It was recorded a decrease in resistance to compression of the consolidated geopolymers of about 5% with 10 wt% addition and of about 77% with the addition of 20 wt% of waste corundum. In any case, the waste abrasive powder does not release heavy metals when added to a geopolymeric formulation based on MK, NaOH, and Na-silicate, and does not show relevant antibacterial properties, indicating the formation of a stable and safe final product with a ceramic-like appearance