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https://www.readbyqxmd.com/read/28306270/quasiparticle-approach-to-molecules-interacting-with-quantum-solvents
#1
Mikhail Lemeshko
Understanding the behavior of molecules interacting with superfluid helium represents a formidable challenge and, in general, requires approaches relying on large-scale numerical simulations. Here, we demonstrate that experimental data collected over the last 20 years provide evidence that molecules immersed in superfluid helium form recently predicted angulon quasiparticles [Phys. Rev. Lett. 114, 203001 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.203001]. Most important, casting the many-body problem in terms of angulons amounts to a drastic simplification and yields effective molecular moments of inertia as straightforward analytic solutions of a simple microscopic Hamiltonian...
March 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28300396/negative-polarity-helium-charge-transfer-dissociation-tandem-mass-spectrometry-radical-initiated-fragmentation-of-complex-polysulfated-anions
#2
David Ropartz, Pengfei Li, Glen P Jackson, Hélène Rogniaux
This work provides the first use of helium charge transfer dissociation (He-CTD) tandem mass spectrometry (MS/MS) in negative polarity mode. Three sulfated oligosaccharides of natural origin were chosen as representative structures that are difficult to solve by conventional MS/MS approaches. Negative polarity He-CTD provided a full set of structurally informative fragments, which permitted the unambiguous determination of the complete structures of these molecules, including the characterization of labile sulfated functional groups...
March 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28280999/histomorphologic-and-ultrastructural-recovery-of-myopathy-in-rats-treated-with-low-level-laser-therapy
#3
Natalia Servetto, David Cremonezzi, Juan Carlos Simes, Antonio Di Pietro, Vilma R Campana
The purpose of the present work was to study the effect of low-level laser therapy (LLLT): helium-neon (He-Ne) and gallium arsenide (Ga-As) laser on the histomorphology of muscle and mitochondria in experimental myopathy in rats. Thirty Suquía strain female rats were distributed in groups: (A) control (intact), (B) injured, (C) injured and treated with He-Ne laser, (D) injured and treated with Ga-As laser, (E) irradiated with He-Ne laser on the non-injured muscle, and (F) irradiated with Ga-As laser on the non-injured muscle...
March 9, 2017: Lasers in Medical Science
https://www.readbyqxmd.com/read/28280806/constructing-accurate-interaction-potentials-to-describe-the-microsolvation-of-protonated-methane-by-helium-atoms
#4
Dennis Kuchenbecker, Felix Uhl, Harald Forbert, Georg Jansen, Dominik Marx
Protonated methane, CH5(+), is not only subject to quasi-rigid vibrational motion which describes its unprotonated parent, CH4, but is dominated by large-amplitude motion even in its quantum ground state. This fluxional behavior leads to hydrogen scrambling which sensitively depends on the underlying flat potential energy surface. Yet, it is largely unknown how fluxional species, such as CH5(+), respond to perturbations arising from microsolvation by weakly interacting species, such as those commonly used as tags in messenger-based vibrational action spectroscopies...
March 10, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28277582/experimental-investigation-of-the-reaction-of-helium-ions-with-dimethyl-ether-stereodynamics-of-the-dissociative-charge-exchange-process
#5
Andrea Cernuto, Paolo Tosi, Luca Matteo Martini, Fernando Pirani, Daniela Ascenzi
The fate of dimethyl ether (DME, CH3OCH3) in collisions with He(+) ions is of high relevance for astrochemical models aimed at reproducing the abundances of complex organic molecules in the interstellar medium. Here we report an investigation on the reaction of He(+) ions with DME carried out using a Guided Ion Beam Mass Spectrometer (GIB-MS), which allows the measurement of reactive cross-sections and branching ratios (BRs) as a function of the collision energy. We obtain insights into the dissociative charge (electron) exchange mechanism by investigating the nature of the non-adiabatic transitions between the relevant potential energy surfaces (PESs) in an improved Landau-Zener approach...
March 9, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28271119/molecular-layer-deposition-of-vanadicone-a-vanadium-based-hybrid-material-as-an-electrode-for-lithium-ion-batteries
#6
Kevin Van de Kerckhove, Felix Mattelaer, Jolien Dendooven, Christophe Detavernier
Molecular layer deposition (MLD) of hybrid organic-inorganic thin films called "vanadicones" was investigated using tetrakisethylmethylaminovanadium (TEMAV) as the metal precursor and glycerol (GL) or ethylene glycol (EG) as the organic reactant. Linear and continued growth could only be achieved with GL as the organic reactant. The TEMAV/GL process displayed self-limiting reactions for both precursor and reactant pulses in the temperature range from 80 °C to 180 °C, with growth rates of 1.2 to 0.5 Å per cycle, respectively...
March 8, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28268388/effects-of-a-non-thermal-plasma-needle-device-on-hpv-16-positive-cervical-cancer-cell-viability-in-vitro
#7
Hollie A Ryan, Johanna Neuber, Shutong Song, Stephen J Beebe, Chunqi Jiang
Non-thermal atmospheric pressure plasma has been demonstrated to inactivate a wide range of surface-dwelling pathogenic microorganisms including airborne viral particles, vegetative bacteria and bacterial spores. This shows the promise of plasma-based decontamination procedures for broad-spectrum sterilization and disinfection and promotes the in-depth and systematic study of how plasma treatment conditions relate to pathogen inactivation efficiency. A wide knowledge gap nonetheless exists regarding whether certain plasma parameters and exposure conditions can alter the resistance of virus-linked cancer cells to treatment...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28264063/acute-death-of-astrocytes-in-blast-exposed-rat-organotypic-hippocampal-slice-cultures
#8
Anna P Miller, Alok S Shah, Brandy V Aperi, Shekar N Kurpad, Brian D Stemper, Aleksandra Glavaski-Joksimovic
Blast traumatic brain injury (bTBI) affects civilians, soldiers, and veterans worldwide and presents significant health concerns. The mechanisms of neurodegeneration following bTBI remain elusive and current therapies are largely ineffective. It is important to better characterize blast-evoked cellular changes and underlying mechanisms in order to develop more effective therapies. In the present study, our group utilized rat organotypic hippocampal slice cultures (OHCs) as an in vitro system to model bTBI. OHCs were exposed to either 138 ± 22 kPa (low) or 273 ± 23 kPa (high) overpressures using an open-ended helium-driven shock tube, or were assigned to sham control group...
2017: PloS One
https://www.readbyqxmd.com/read/28258643/charge-transfer-dissociation-ctd-of-phosphocholines-gas-phase-ion-ion-reactions-between-helium-cations-and-phospholipid-cations
#9
Pengfei Li, Glen P Jackson
Phospholipid cations formed by electrospray ionization were subjected to excitation and fragmentation by a beam of 6 keV helium cations in a process termed charge transfer dissociation (CTD). The resulting fragmentation pattern in CTD is different from that of conventional collision-induced dissociation (CID), but analogous to that of metastable atom-activated dissociation (MAD) and electron-induced dissociation (EID). Like CID, CTD yields product ions indicative of acyl chain lengths and degrees of unsaturation in the fatty acyl moieties, but also provides additional structural diagnostic information, such as double bond position...
March 4, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28257003/magnetocardiography-measurements-with-sup-4-sup-he-vector-optically-pumped-magnetometers-at-room-temperature
#10
Sophie Morales, Marie-Constance Corsi, William Fourcault, François Bertrand, Gilles Cauffet, Cyril Gobbo, François Alcouffe, François Lenouvel, Matthieu Le Prado, François Berger, Gerald Vanzetto, Etienne Labyt
In this paper, we present a proof of concept study which demonstrates for the first time the possibility to record magnetocardiography (MCG) signals with 4He vector optically-pumped magnetometers (OPM) operated in a gradiometer mode. Resulting from a compromise between sensitivity, size and operability in a clinical environment, the developed magnetometers are based on the parametric resonance of helium in zero magnetic field. Sensors are operated at room-temperature and provide a tri-axis vector measurement of the magnetic field...
March 3, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28256871/numerical-investigation-of-thermal-counterflow-of-he-ii-past-cylinders
#11
Cyprien Soulaine, Michel Quintard, Bertrand Baudouy, Rob Van Weelderen
We investigate numerically, for the first time, the thermal counterflow of superfluid helium past a cylinder by solving with a finite volume method the complete so-called two-fluid model. In agreement with existing experimental results, we obtain symmetrical eddies both up- and downstream of the obstacle. The generation of these eddies is a complex transient phenomenon that involves the friction of the normal fluid component with the solid walls and the mutual friction between the superfluid and normal components...
February 17, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28256134/formation-of-exotic-networks-of-water-clusters-in-helium-droplets-facilitated-by-the-presence-of-neon-atoms
#12
Gary E Douberly, Roger E Miller, Sotiris S Xantheas
Water clusters are formed in helium droplets via the sequential capture of monomers. One or two neon atoms are added to each droplet prior to the addition of water. The infrared spectrum of the droplet ensemble reveals several signatures of polar, water tetramer clusters having dipole moments between 2D and 3D. Comparison with ab initio computations supports the assignment of the cluster networks to noncyclic "3 + 1" clusters, which are ∼5.3 kcal/mol less stable than the global minimum nonpolar cyclic tetramer...
March 8, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28253619/determination-of-peroxide-explosive-tatp-and-related-compounds-by-dielectric-barrier-discharge-ionization-mass-spectrometry-dbdi-ms
#13
Sebastian Hagenhoff, Joachim Franzke, Heiko Hayen
Dielectric barrier discharge ionization-mass spectrometry (DBDI-MS), which is based on the use of a low temperature helium plasma as ionization source, is used for the determination of trace amounts of triacetone triperoxide (TATP) and its homologue diacetone diperoxide (DADP) from surfaces. TATP is observed as [M+NH4](+) adduct, whereas DADP is observed as [M+O+NH4](+). Measurement of DADP with varying deuteration degrees (DADP, DADP-d6 and DADP-d12) indicates that DADP undergoes oxidation when ionized by DBDI...
March 3, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28252222/irradiation-of-mesenchymal-stromal-cells-with-low-and-high-doses-of-alpha-particles-induces-senescence-and-or-apoptosis
#14
Nicola Alessio, Giuseppe Esposito, Giovanni Galano, Roberto De Rosa, Pasquale Anello, Gianfranco Peluso, Maria Antonella Tabocchini, Umberto Galderisi
The use of high-linear energy transfer charged particles is gaining attention as a medical tool because of the emission of radiations with an efficient cell-killing ability. Considerable interest has developed in the use of targeted alpha-particle therapy for the treatment of micrometastases. Moreover, the use of helium beams is gaining momentum, especially for treating pediatric tumors. We analyzed the effects of alpha particles on bone marrow mesenchymal stromal cells (MSCs), which have a subpopulation of stem cells capable of generating adipocytes, chondrocytes, and osteocytes...
March 2, 2017: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/28252072/supersolid-formation-in-a-quantum-gas-breaking-a-continuous-translational-symmetry
#15
Julian Léonard, Andrea Morales, Philip Zupancic, Tilman Esslinger, Tobias Donner
The concept of a supersolid state combines the crystallization of a many-body system with dissipationless flow of the atoms from which it is built. This quantum phase requires the breaking of two continuous symmetries: the phase invariance of a superfluid and the continuous translational invariance to form the crystal. Despite having been proposed for helium almost 50 years ago, experimental verification of supersolidity remains elusive. A variant with only discrete translational symmetry breaking on a preimposed lattice structure-the 'lattice supersolid'-has been realized, based on self-organization of a Bose-Einstein condensate...
March 1, 2017: Nature
https://www.readbyqxmd.com/read/28248644/defective-germanene-as-a-high-efficiency-helium-separation-membrane-a-first-principles-study
#16
Lei Zhu, Xiao Chang, Daliang He, Qingzhong Xue, Xiaofang Li, Yakang Jin, Haixia Zheng, Cuicui Ling
Development of low energy cost membranes for separating helium from natural gas is highly desired. Using van der Waals-corrected first-principles density functional theory (DFT) calculations, we theoretically investigate the helium separation performance of divacancy-defective germanene. The 555 777 divacancy-defective germanene presents a 0.53 eV energy barrier for helium, which is slightly larger than the energy threshold value of gas molecule penetration of a membrane (0.5 eV). Thus, the 555 777 divacancy-defective germanene is difficult for helium to permeate, except under high temperature or pressure...
March 1, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28240810/ultraviolet-320-nm-laser-excitation-for-flow-cytometry
#17
William Telford, Lynn Stickland, Marco Koschorreck
Although multiple lasers and high-dimensional analysis capability are now standard on advanced flow cytometers, ultraviolet (UV) lasers (usually 325-365 nm) remain an uncommon excitation source for cytometry. This is primarily due to their cost, and the small number of applications that require this wavelength. The development of the Brilliant Ultraviolet (BUV fluorochromes, however, has increased the importance of this formerly niche excitation wavelength. Historically, UV excitation was usually provided by water-cooled argon- and krypton-ion lasers...
February 27, 2017: Cytometry. Part A: the Journal of the International Society for Analytical Cytology
https://www.readbyqxmd.com/read/28230008/analysis-of-therapeutic-effectiveness-and-prognostic-factor-on-argon-helium-cryoablation-combined-with-transcatheter-arterial-chemoembolization-for-the-treatment-of-advanced-hepatocellular-carcinoma
#18
Chen Huang, Weizhao Zhuang, Huigang Feng, Huizhuang Guo, Yukuan Tang, Hanwei Chen, Yi Huang
OBJECTIVE: The objective of this study was to evaluate the effectiveness on argon-helium cryoablation combined with transcatheter arterial chemoembolization (TACE) in treating advanced hepatocellular carcinoma (HCC) and its influence factor. MATERIALS AND METHODS: This trial was approved by the Guangzhou Panyu Central Hospital Ethics Committee. This was a prospective, single-center study conducted in Guangzhou Panyu Central Hospital. After informed consent was obtained, the prospective randomized clinical data of 120 patients with advanced HCC were collected...
December 2016: Journal of Cancer Research and Therapeutics
https://www.readbyqxmd.com/read/28226554/effects-of-a-non-thermal-plasma-needle-device-on-hpv-16-positive-cervical-cancer-cell-viability-in-vitro
#19
Hollie A Ryan, Johanna Neuber, Shutong Song, Stephen J Beebe, Chunqi Jiang, Hollie A Ryan, Johanna Neuber, Shutong Song, Stephen J Beebe, Chunqi Jiang, Shutong Song, Johanna Neuber, Chunqi Jiang, Stephen J Beebe, Hollie A Ryan
Non-thermal atmospheric pressure plasma has been demonstrated to inactivate a wide range of surface-dwelling pathogenic microorganisms including airborne viral particles, vegetative bacteria and bacterial spores. This shows the promise of plasma-based decontamination procedures for broad-spectrum sterilization and disinfection and promotes the in-depth and systematic study of how plasma treatment conditions relate to pathogen inactivation efficiency. A wide knowledge gap nonetheless exists regarding whether certain plasma parameters and exposure conditions can alter the resistance of virus-linked cancer cells to treatment...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225584/preferential-alignment-of-incommensurate-block-copolymer-dot-arrays-forming-moir%C3%A3-superstructures
#20
Cong Jin, Brian C Olsen, Erik J Luber, Jillian M Buriak
Block copolymer (BCP) self-assembly is of great interest as a cost-effective method for large-scale, high-resolution nanopattern fabrication. Directed self-assembly can induce long-range order and registration, reduce defect-density, and enable access to patterns of higher complexity. Here we demonstrate preferential orientation of two incommensurate BCP dot arrays. A bottom layer of hexagonal silica dots is prepared via typical self-assembly from a PS-b-PDMS block copolymer. Self-assembly of a second, or top, layer of a different a PS-b-PDMS block copolymer that forms a hexagonal dot pattern with different periodicity, results in a predictable Moiré superstructure...
February 22, 2017: ACS Nano
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