26 research outputs found

    Salting-out effects by pressure-corrected 3D-RISM

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    In this paper, we demonstrate that using a pressure corrected three-dimensional reference interaction site model (3D-RISM/PC+) one can accurately predict salting-out (Setschenow's) constants for a wide range of organic compounds in aqueous solutions of NaCl. The approach, based on classical molecular force fields, offers an alternative to more heavily parametrized methods

    The electrophysical properties of polytolans and polydiphenylbutadiyne and the relationship between these and supermolecular structure

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    A polymer of tolan, obtained by thermal polymerization, and polymers of tolan and diphenylbutadiyne, obtained by anionic polymerization, have been studied by the space charge-limiyted current method. The energy of activation for conduction, the mobility and concentration of the charge carriers and the density and depth of the traps were found. It is shown that in polymers containing a conjugated double bond system there are traps grouped about fundamental trapping level. © 1977

    Measles: An overview of a re-emerging disease in children and immunocompromised patients

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    Despite the availability of a safe and effective vaccine, in 2018, around 350,000 measles cases were reported worldwide, which resulted in an estimate of 142,300 deaths from measles. Additionally, in 2017, global measles cases spiked, causing the death of 110,000 people, mostly children under the age of 5 years and immunocompromised adults. The increase in measles incidence is caused by the ongoing reduction of vaccination coverage. This event has triggered public and scientific interest. For this reason, we reviewed the pathophysiology of measles infection, focusing on mechanisms by which the virus spreads systemically through the host organism. By reaching the lymphocytes from the airways through a \u201ctrojan horse\u201d strategy, measles induces an immunosuppression status. H and F glycoproteins, both expressed in the envelope, ensure attachment of the virus to host cells and spreading from one cell to another by binding to several receptors, as described in detail. The severity of the disease depends both on the age and underlying conditions of patients as well as the social and health context in which epidemics spread, and is often burdened by sequelae and complications that may occur several years after infection. Particular attention was paid to special groups that are more susceptible to severe or atypical measles. An overview of microbiology, symptoms, diagnosis, prevention, and treatment completes and enriches the review

    Launch of the Space experiment PAMELA

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    PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of 10^-8). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15, 2006 in a 350*600 km orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. In self-trigger mode the Calorimeter, the neutron detector and a shower tail catcher are capable of an independent measure of the lepton component up to 2 TeV. In this work we describe the experiment, its scientific objectives and the performance in the first months after launch.Comment: Accepted for publication on Advances in Space Researc

    PAMELA - A Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics

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    The PAMELA experiment is a satellite-borne apparatus designed to study charged particles in the cosmic radiation with a particular focus on antiparticles. PAMELA is mounted on the Resurs DK1 satellite that was launched from the Baikonur cosmodrome on June 15th 2006. The PAMELA apparatus comprises a time-of-flight system, a magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows antiparticles to be reliably identified from a large background of other charged particles. This paper reviews the design, space qualification and on-ground performance of PAMELA. The in-orbit performance will be discussed in future publications.The PAMELA experiment is a satellite-borne apparatus designed to study charged particles in the cosmic radiation with a particular focus on antiparticles. PAMELA is mounted on the Resurs DK1 satellite that was launched from the Baikonur cosmodrome on June 15th 2006. The PAMELA apparatus comprises a time-of-flight system, a magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows antiparticles to be reliably identified from a large background of other charged particles. This paper reviews the design, space qualification and on-ground performance of PAMELA. The in-orbit performance will be discussed in future publications

    The influence of solid state information and descriptor selection on statistical models of temperature dependent aqueous solubility.

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    Predicting the equilibrium solubility of organic, crystalline materials at all relevant temperatures is crucial to the digital design of manufacturing unit operations in the chemical industries. The work reported in our current publication builds upon the limited number of recently published quantitative structure-property relationship studies which modelled the temperature dependence of aqueous solubility. One set of models was built to directly predict temperature dependent solubility, including for materials with no solubility data at any temperature. We propose that a modified cross-validation protocol is required to evaluate these models. Another set of models was built to predict the related enthalpy of solution term, which can be used to estimate solubility at one temperature based upon solubility data for the same material at another temperature. We investigated whether various kinds of solid state descriptors improved the models obtained with a variety of molecular descriptor combinations: lattice energies or 3D descriptors calculated from crystal structures or melting point data. We found that none of these greatly improved the best direct predictions of temperature dependent solubility or the related enthalpy of solution endpoint. This finding is surprising because the importance of the solid state contribution to both endpoints is clear. We suggest our findings may, in part, reflect limitations in the descriptors calculated from crystal structures and, more generally, the limited availability of polymorph specific data. We present curated temperature dependent solubility and enthalpy of solution datasets, integrated with molecular and crystal structures, for future investigations

    The electrophysical properties of polytolans and polydiphenylbutadiyne and the relationship between these and supermolecular structure

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    A polymer of tolan, obtained by thermal polymerization, and polymers of tolan and diphenylbutadiyne, obtained by anionic polymerization, have been studied by the space charge-limiyted current method. The energy of activation for conduction, the mobility and concentration of the charge carriers and the density and depth of the traps were found. It is shown that in polymers containing a conjugated double bond system there are traps grouped about fundamental trapping level. © 1977

    The electrophysical properties of polytolans and polydiphenylbutadiyne and the relationship between these and supermolecular structure

    No full text
    A polymer of tolan, obtained by thermal polymerization, and polymers of tolan and diphenylbutadiyne, obtained by anionic polymerization, have been studied by the space charge-limiyted current method. The energy of activation for conduction, the mobility and concentration of the charge carriers and the density and depth of the traps were found. It is shown that in polymers containing a conjugated double bond system there are traps grouped about fundamental trapping level. © 1977

    The electrophysical properties of polytolans and polydiphenylbutadiyne and the relationship between these and supermolecular structure

    Get PDF
    A polymer of tolan, obtained by thermal polymerization, and polymers of tolan and diphenylbutadiyne, obtained by anionic polymerization, have been studied by the space charge-limiyted current method. The energy of activation for conduction, the mobility and concentration of the charge carriers and the density and depth of the traps were found. It is shown that in polymers containing a conjugated double bond system there are traps grouped about fundamental trapping level. © 1977

    Anionic Polymerization of Para-Diethynylbenzene: Synthesis of a Strictly Linear Polymer

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    Anionic homo- and copolymerization of p-diethynylbenzene in the presence of n-BuLi in polar solvents was carried out. The use of hexamethylphosphortriamide (HMPA) makes it possible to synthesize a completely linear soluble polymer that does not have branching and phenylene fragments. A copolymer of p-diethynylbenzene with diphenyldiacetylene was synthesized. Homo- and copolymers of p-diethynylbenzene have high thermo- and thermo-oxidative stability. By the interaction of side reactive ethynylphenylene groups with various reagents, it is proposed to synthesize clusters along the conducting chain of poly-p-diethynylbenzene. Due to presenting C≡CH side groups, boron, copper, and cobalt derivatives were synthesized. It is shown that not all theoretically possible stereoisomers can be formed as a result of the polymerization. The application of p-diethynylbenzene polymers for the modification of industrial samples of epoxy novolac resin, oligoester acrylates, and carbon fibers has been demonstrated
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