Differences in infrared spectroscopic data of connective tissues in transflectance and transmittance modes

Fourier transform infrared imaging spectroscopy (FT-IRIS) has been used extensively to characterize the composition and orientation of macromolecules in thin tissue sections. Earlier and current studies of normal and polarized FT-IRIS data have primarily used tissues sectioned onto infrared transmissive substrates, such as salt windows. Recently, the use of low-emissivity (“low-e”) substrates has become of great interest because of their low cost and favorable infrared optical properties. However, data are collected in transflectance mode when using low-e slides and in transmittance mode using salt windows. In the current study we investigated the comparability of these two modes for assessment of the composition of connective tissues. FT-IRIS data were obtained in transflectance and transmittance modes from serial sections of cartilage, bone and tendon, and from a standard polymer, polymethylmethacrylate. Both non-polarized and polarized FTIR data differed in absorbance, and in some cases peak position, between transflectance and transmittance modes. However, the FT-IRIS analysis of the collagen fibril orientation in cartilage resulted in the expected zonal arrangement of fibrils in both transmittance and transflectance. We conclude that numerical comparison of FT-IRIS-derived parameters of tissue composition should account for substrate type and data collection mode, while analysis of overall tissue architecture may be more invariant between modes.     

Natural coumarins. Part XIV. synthesis of some isoprenyl ethers of psoralene hydroquinone and related products

Partial demethylation of isopimpinellin and methylation of psoralene hydroquinone afforded 5-methoxy-9-hydroxypsoralene. The corresponding 5-isoprenyloxy derivative was used in the synthesis of cnidilin and its epoxy and glycol derivatives, which are all biogenetically feasible; the fatter two having as yet not been isolated from natural sources.     

A sweep-based algorithm for the fleet size and mix vehicle routing problem

This paper presents a new sweep-based heuristic for the fleet size and mix vehicle routing problem. This problem involves two kinds of decisions: the selection of a mix of vehicles among the available vehicle types and the routing of the selected fleet. The proposed algorithm first generates a large number of routes that are serviced by one or two vehicles. The selection of routes and vehicles to be used is then made by solving to optimality, in polynomial time, a set-partitioning problem having a special structure. Results on a set of benchmark test problems show that the proposed heuristic produces excellent solutions in short computing times. Having a fast but good solution method is needed for transportation companies that rent a significant part of their fleet and consequently can take advantage of frequent changes in fleet composition. Finally, the proposed heuristic produced new best-known solutions for three of the test problems; these solutions are reported.     

Model-independent Veltman condition,naturalness and the little hierarchy problem

We adopt a bottom-up Effective Field Theory(EFT)approach to derive a model-independent Veltman condition to cancel out the quadratic divergences in the Higgs mass.We show using the equivalence theorem that all the deviations in the Higgs couplings to the W and Z from the SM predictions should vanish.We argue based on tree-level unitarity that any new physics that naturally cancels out the quadratic divergences should be ≤19 TeV.We show that the level of fine-tuning required is unless the O(0:1%-1%) UV sector has a symmetry that forces the satisfaction of the model-independent Veltman condition,in which case all fine-tuning is eliminated.We also conjecture that,if no new physics that couples to the Higgs is observed up to~19 TeV,or if the Higgs couplings to the SM particles conform to the SM predictions,then the Higgs either does not couple to any UV sector or is fine-tuned.     

Transition temperature model based on specific heat data of an FeAs-based superconductor

In this article, we studied the specific heat data of iron-based superconductors LaO_{1? x} F _x FeAs (x?=?0.1) and SmO_{1? x} F _x FeAs (x?=?0.13,?0.12, and 0.1). (i) The contribution of phonons in specific heat above T_c depends exponentially on temperature. (ii) The specific heat has different contributions, and they change differently at T_c . This change must be the effect of a physical function on heat capacity. Therefore, transition temperature is defined by thermal parameters. For LaO_0.9F_0.1FeAs and SmO_0.87F_0.13FeAs, a transition point was evaluated at 22.11 and 26.32?K, respectively. This is in close agreement with the midpoint transition temperatures obtained from dc resistivity and magnetization experiments, where the modified electronic heat capacity led to the approximate value of the transition point in two samples. The jump, ΔC/γT _c, and the electronic and lattice heat capacity coefficients, γ and β, respectively, were evaluated.     

Photodegradation of Carbaryl in Acetonitrile Solution

The photochemical decomposition, induced by UV radiation, of the carbamate pesticide (Carbaryl) in acetonitrile has been examined by means of gas chromatography–Mass spectrometry (GC‐MS). The result of continuous irradiation was almost total degradation of the pesticide examined. In order to investigate the nature of the reaction products, a spectroscopic study (UV‐Vis, steady‐state fluorescence, and fluorescence lifetime) of the products was performed. Phthalic anhydride and traces of 1,4‐naphtalenedione as an intermediate were detected as reaction products. The presence of a trace amount of 1‐naphthol as one of the photoproducts was confirmed by fluorescence lifetime measurements.     

A new application of thin-layer chromatography. Chemical reactions induced on the adsorbent

Summary A new application of the chromatoplate technique is reported in which a chemical reaction can be induced on a chromatographic adsorbent under controlled conditions. The products of the reaction can then be resolved in a conventional thinlayer chromatographic procedure and compared with the expected substances on the same chromatogram. Several types of model compounds were subjected to some common reactions: acetylation, saponification, oxidation, reduction, hydrogenation, bromination, nitration, esterification, etherification, mineral acid treatment, chloride formation, acetonide formation and 2,4-dinitrophenylhydrazone formation.

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Zusammenfassung Es wird eine neue Anwendung der dünnschichtchromatographischen Technik beschrieben, bei der auf dem Adsorbens unter kontrollierten Bedingungen eine chemische Reaktion durchgeführt wird. Die Reaktionsprodukte können dann anschließend chromatographiert und mit einer entsprechenden Musterprobe verglichen werden. Mit verschiedenartigen Verbindungstypen wurden folgende Reaktionen ausgeführt: Acetylierung, Verseifung, Oxydation, Reduktion, Hydrierung, Bromierung, Nitrierung, Veresterung, Bildung von Äthern, Chloriden, Acetonderivaten und 2,4-Dinitrophenylhydrazonen, sowie Behandlung mit Mineralsäuren.

     

Ozonolyse d'olefines perfluorees

We have obtained unusually stable secondaxy ozonides ($\text{2a-c}$) by heating neat perfluoroalkenes ($\text{1a-c}$) with ozone.