The association between acute flaccid myelitis (AFM) and Enterovirus D68 (EV-D68) – what is the evidence for causation?

PubMed Central

Dyda, Amalie; Stelzer-Braid, Sacha; Adam, Dillon; Chughtai, Abrar A; MacIntyre, C Raina

2018-01-01

Background Enterovirus D68 (EV-D68) has historically been a sporadic disease, causing occasional small outbreaks of generally mild infection. In recent years, there has been evidence of an increase in EV-D68 infections globally. Large outbreaks of EV-D68, with thousands of cases, occurred in the United States, Canada and Europe in 2014. The outbreaks were associated temporally and geographically with an increase in clusters of acute flaccid myelitis (AFM).
Aims: We aimed to evaluate a causal association between EV-D68 and AFM. 
Methods: Using data from the published and grey literature, we applied the Bradford Hill criteria, a set of nine principles applied to examine causality, to evaluate the relationship between EV-D68 and AFM. Based on available evidence, we defined the Bradford Hill Criteria as being not met, or met minimally, partially or fully. 
Results: Available evidence applied to EV-D68 and AFM showed that six of the Bradford Hill criteria were fully met and two were partially met. The criterion of biological gradient was minimally met. The incidence of EV-D68 infections is increasing world-wide. Phylogenetic epidemiology showed diversification from the original Fermon and Rhyne strains since the year 2000, with evolution of a genetically distinct outbreak strain, clade B1. Clade B1, but not older strains, is associated with AFM and is neuropathic in animal models. 
Conclusion: While more research is needed on dose–response relationship, application of the Bradford Hill criteria supported a causal relationship between EV-D68 and AFM. PMID:29386095

First Report of a Fatal Case Associated with EV-D68 Infection in Hong Kong and Emergence of an Interclade Recombinant in China Revealed by Genome Analysis.

PubMed

Yip, Cyril C Y; Lo, Janice Y C; Sridhar, Siddharth; Lung, David C; Luk, Shik; Chan, Kwok-Hung; Chan, Jasper F W; Cheng, Vincent C C; Woo, Patrick C Y; Yuen, Kwok-Yung; Lau, Susanna K P

2017-05-16

A fatal case associated with enterovirus D68 (EV-D68) infection affecting a 10-year-old boy was reported in Hong Kong in 2014. To examine if a new strain has emerged in Hong Kong, we sequenced the partial genome of the EV-D68 strain identified from the fatal case and the complete VP1, and partial 5'UTR and 2C sequences of nine additional EV-D68 strains isolated from patients in Hong Kong. Sequence analysis indicated that a cluster of strains including the previously recognized A2 strains should belong to a separate clade, clade D, which is further divided into subclades D1 and D2. Among the 10 EV-D68 strains, 7 (including the fatal case) belonged to the previously described, newly emerged subclade B3, 2 belonged to subclade B1, and 1 belonged to subclade D1. Three EV-D68 strains, each from subclades B1, B3, and D1, were selected for complete genome sequencing and recombination analysis. While no evidence of recombination was noted among local strains, interclade recombination was identified in subclade D2 strains detected in mainland China in 2008 with VP2 acquired from clade A. This study supports the reclassification of subclade A2 into clade D1, and demonstrates interclade recombination between clades A and D2 in EV-D68 strains from China.

Investigation of thermoelectricity in KScSn half-Heusler compound

NASA Astrophysics Data System (ADS)

Shrivastava, Deepika; Acharya, Nikita; Sanyal, Sankar P.

2018-05-01

The electronic and transport properties of KScSn half-Heusler (HH) compound have been investigated using first-principles density functional theory and semi classical Boltzmann transport theory. The electronic band structure and density of states (total and partial) show semiconducting nature of KScSn with band gap 0.48 eV which agree well with previously reported results. The transport coefficient such as electrical conductivity, Seebeck coefficient, electronic thermal conductivity and power factor as a function of chemical potential are evaluated. KScSn has high power factor for p-type doping and is a potential candidate for thermoelectric applications.

Dissociative and double photoionization cross sections of NO from threshold to 120 A

NASA Technical Reports Server (NTRS)

Samson, J. A. R.; Masuoka, T.; Pareek, P. N.

1985-01-01

The partial photoionization cross sections for producing the NO(+) parent ion and the O(+), N(+), and NO(2+) fragmentations from neutral NO are presented from 120 to 614 A. The results indicate predissociation of the 3 pi (21.72 eV) and B-prime 1Sigma(+) (22.73 eV) electronic states of NO(+). The photoionization threshold for double ionization was found to be 39.4 + or - 0.12 eV.

Low temperature time resolved photoluminescence in ordered and disordered Cu2ZnSnS4 single crystals

NASA Astrophysics Data System (ADS)

Raadik, Taavi; Krustok, Jüri; Kauk-Kuusik, M.; Timmo, K.; Grossberg, M.; Ernits, K.; Bleuse, J.

2017-03-01

In this work we performed time-resolved micro-photoluminescence (TRPL) studies of Cu2ZnSnS4 (CZTS) single crystals grown in molten KI salt. The order/disorder degree of CZTS was varied by the thermal post treatment temperature. Photoluminescence spectra measured at T=8 K showed an asymmetric band with a peak position of 1.33 eV and 1.27 eV for partially ordered and disordered structures, respectively. Thermal activation energies were found to be ET (PO) =65±9 meV for partially ordered and ET (PD) =27±4 meV for partially disordered. These low activation energy values indicating to the defect cluster recombination model for both partially ordered and disordered structures. TRPL was measured for both crystals and their decay curves were fitted with a stretched exponential function, in order to describe the charge carriers' recombination dynamics at low temperature.

Heparin affinity purification of extracellular vesicles

PubMed Central

Balaj, Leonora; Atai, Nadia A.; Chen, Weilin; Mu, Dakai; Tannous, Bakhos A.; Breakefield, Xandra O.; Skog, Johan; Maguire, Casey A.

2015-01-01

Extracellular vesicles (EVs) are lipid membrane vesicles released by cells. They carry active biomolecules including DNA, RNA, and protein which can be transferred to recipient cells. Isolation and purification of EVs from culture cell media and biofluids is still a major challenge. The most widely used isolation method is ultracentrifugation (UC) which requires expensive equipment and only partially purifies EVs. Previously we have shown that heparin blocks EV uptake in cells, supporting a direct EV-heparin interaction. Here we show that EVs can be purified from cell culture media and human plasma using ultrafiltration (UF) followed by heparin-affinity beads. UF/heparin-purified EVs from cell culture displayed the EV marker Alix, contained a diverse RNA profile, had lower levels of protein contamination, and were functional at binding to and uptake into cells. RNA yield was similar for EVs isolated by UC. We were able to detect mRNAs in plasma samples with comparable levels to UC samples. In conclusion, we have discovered a simple, scalable, and effective method to purify EVs taking advantage of their heparin affinity. PMID:25988257

Ab initio molecular dynamics simulations of low energy recoil events in MgO

NASA Astrophysics Data System (ADS)

Petersen, B. A.; Liu, B.; Weber, W. J.; Zhang, Y.

2017-04-01

Low-energy recoil events in MgO are studied using ab intio molecular dynamics simulations to reveal the dynamic displacement processes and final defect configurations. Threshold displacement energies, Ed, are obtained for Mg and O along three low-index crystallographic directions, [100], [110], and [111]. The minimum values for Ed are found along the [110] direction consisting of the same element, either Mg or O atoms. Minimum threshold values of 29.5 eV for Mg and 25.5 eV for O, respectively, are suggested from the calculations. For other directions, the threshold energies are considerably higher, 65.5 and 150.0 eV for O along [111] and [100], and 122.5 eV for Mg along both [111] and [100] directions, respectively. These results show that the recoil events in MgO are partial-charge transfer assisted processes where the charge transfer plays an important role. There is a similar trend found in other oxide materials, where the threshold displacement energy correlates linearly with the peak partial-charge transfer, suggesting this behavior might be universal in ceramic oxides.

Dissociative and double photoionization cross sections of NO from threshold to 120 A

NASA Technical Reports Server (NTRS)

Samson, J. A. R.; Masuoka, T.; Pareek, P. N.

1985-01-01

The partial photoionization cross sections for producing the NO(+) parent ion and the O(+), N(+), and NO2(+) fragment ions from neutral NO are presented from 120 to 614 A. The results indicate predissociation of the c(sup3) pi (21.72 eV) and B prime (sup 1) sigma (+) (22.73 eV) electronic states of NO(+). The photoionization threshold for double ionization was found to be 39.4 + or 0.12 eV.

Determining the partial photoionization cross-sections of ethyl radicals.

PubMed

FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

2007-12-13

Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

Shift of Enterovirus species among children in Cameroon--identification of a new enterovirus, EV-A119.

PubMed

Ayukekbong, James; Kabayiza, Jean-Claude; Lindh, Magnus; Nkuo-Akenji, Theresia; Tah, Ferdinand; Bergström, Tomas; Norder, Helene

2013-09-01

Infections caused by human enteroviruses (EVs) are often asymptomatic or mild, although they may cause more severe illnesses as meningitis and acute flaccid paralysis. EVs have globally posed a threat to children, and outbreaks of aseptic meningitis and hand, foot and mouth disease are frequently reported. To identify EV strains circulating among healthy children in a small community in Limbe, Cameroon two years apart. Species and EV types were obtained by partial 5'UTR-VP4 and VP1 sequencing of RNA from stool samples collected in October 2009 and September 2011 from 150 children in Cameroon. In all, 74 children (49%) were infected with 28 different types of EV. There were 29 (54%) infected children in 2009, and 45 (47%) in 2011. There was a significant difference between detected species of EV, with 15 (47%) children infected with EV-A in 2009, and 22 (71%) with EV-B in 2011 (p=0.0001). In 2009, one child was infected by a divergent EV, which was most similar to EV-A90. Based on the complete VP1 sequence, it was shown to be a new EV designated EV-A119. The current study shows a high heterogeneity of circulating EV types among children in Limbe, Cameroon, and a previously not described shift in predominating EV species. Copyright © 2013 Elsevier B.V. All rights reserved.

State-resolved differential and integral cross sections for the Ne + H{sub 2}{sup +} (v = 0–2, j = 0) → NeH{sup +} + H reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Hui; Yao, Cui-Xia; He, Xiao-Hu

State-to-state quantum dynamic calculations for the proton transfer reaction Ne + H{sub 2}{sup +} (v = 0–2, j = 0) are performed on the most accurate LZHH potential energy surface, with the product Jacobi coordinate based time-dependent wave packet method including the Coriolis coupling. The J = 0 reaction probabilities for the title reaction agree well with previous results in a wide range of collision energy of 0.2-1.2 eV. Total integral cross sections are in reasonable agreement with the available experiment data. Vibrational excitation of the reactant is much more efficient in enhancing the reaction cross sections than translational andmore » rotational excitation. Total differential cross sections are found to be forward-backward peaked with strong oscillations, which is the indication of the complex-forming mechanism. As the collision energy increases, state-resolved differential cross section changes from forward-backward symmetric peaked to forward scattering biased. This forward bias can be attributed to the larger J partial waves, which makes the reaction like an abstraction process. Differential cross sections summed over two different sets of J partial waves for the v = 0 reaction at the collision energy of 1.2 eV are plotted to illustrate the importance of large J partial waves in the forward bias of the differential cross sections.« less

Recombination in the evolution of enterovirus C species sub-group that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99.

PubMed

Smura, Teemu; Blomqvist, Soile; Vuorinen, Tytti; Ivanova, Olga; Samoilovich, Elena; Al-Hello, Haider; Savolainen-Kopra, Carita; Hovi, Tapani; Roivainen, Merja

2014-01-01

Genetic recombination is considered to be a very frequent phenomenon among enteroviruses (Family Picornaviridae, Genus Enterovirus). However, the recombination patterns may differ between enterovirus species and between types within species. Enterovirus C (EV-C) species contains 21 types. In the capsid coding P1 region, the types of EV-C species cluster further into three sub-groups (designated here as A-C). In this study, the recombination pattern of EV-C species sub-group B that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99 was determined using partial 5'UTR and VP1 sequences of enterovirus strains isolated during poliovirus surveillance and previously published complete genome sequences. Several inter-typic recombination events were detected. Furthermore, the analyses suggested that inter-typic recombination events have occurred mainly within the distinct sub-groups of EV-C species. Only sporadic recombination events between EV-C species sub-group B and other EV-C sub-groups were detected. In addition, strict recombination barriers were inferred for CVA-21 genotype C and CVA-24 variant strains. These results suggest that the frequency of inter-typic recombinations, even within species, may depend on the phylogenetic position of the given viruses.

Inclusion of electron correlation for the target wave function in low- to intermediate-energy e-N2 scattering

NASA Technical Reports Server (NTRS)

Weatherford, C. A.; Brown, F. B.; Temkin, A.

1987-01-01

In a recent calculation, an exact exchange method was developed for use in the partial-differential-equation approach to electron-molecule scattering and was applied to e-N2 scattering in the fixed-nuclei approximation with an adiabatic polarization potential at low energies (0-10 eV). Integrated elastic cross sections were calculated and found to be lower than experiment at energies both below and above the Pi(g) resonance. It was speculated at that time that improved experimental agreement could be obtained if a correlated target representation were used in place of the uncorrelated one. The present paper implements this suggestion and demonstrates the improved agreement. These calculations are also extended to higher energies (0-30 eV) so asd to include the Sigma(u) resonance. Some discrepancies among the experiments and between experiment and the various calculations at very low energy are noted.

Modulation of band gap by an applied electric field in BN-based heterostructures

NASA Astrophysics Data System (ADS)

Luo, M.; Xu, Y. E.; Zhang, Q. X.

2018-05-01

First-principles density functional theory (DFT) calculations are performed on the structural and electronic properties of the SiC/BN van der Waals (vdW) heterostructures under an external electric field (E-field). Our results reveal that the SiC/BN vdW heterostructure has a direct band gap of 2.41 eV in the raw. The results also imply that electrons are likely to transfer from BN to SiC monolayer due to the deeper potential of BN monolayer. It is also observed that, by applying an E-field, ranging from -0.50 to +0.65 V/Å, the band gap decreases from 2.41 eV to zero, which presents a parabola-like relationship around 0.0 V/Å. Through partial density of states (PDOS) plots, it is revealed that, p orbital of Si, C, B, and N atoms are responsible for the significant variations of band gap. These obtained results predict that, the electric field tunable band gap of the SiC/BN vdW heterostructures carries potential applications for nanoelectronics and spintronic device applications.

High frequency of Polio-like Enterovirus C strains with differential clustering of CVA-13 and EV-C99 subgenotypes in a cohort of Malawian children.

PubMed

Brouwer, Lieke; van der Sanden, Sabine M G; Calis, Job C J; Bruning, Andrea H L; Wang, Steven; Wildenbeest, Joanne G; Rebers, Sjoerd P H; Phiri, Kamija S; Westerhuis, Brenda M; van Hensbroek, Michaël Boele; Pajkrt, Dasja; Wolthers, Katja C

2018-05-28

Enteroviruses (EVs) are among the most commonly detected viruses infecting humans worldwide. Although the prevalence of EVs is widely studied, the status of EV prevalence in sub-Saharan Africa remains largely unknown. The objective of our present study was therefore to increase our knowledge on EV circulation in sub-Saharan Africa. We obtained 749 fecal samples from a cross-sectional study conducted on Malawian children aged 6 to 60 months. We tested the samples for the presence of EVs using real time PCR, and typed the positive samples based on partial viral protein 1 (VP1) sequences. A large proportion of the samples was EV positive (89.9%). 12.9% of the typed samples belonged to EV species A (EV-A), 48.6% to species B (EV-B) and 38.5% to species C (EV-C). More than half of the EV-C strains (53%) belonged to subgroup C containing, among others, Poliovirus (PV) 1-3. The serotype most frequently isolated in our study was CVA-13, followed by EV-C99. The strains of CVA-13 showed a vast genetic diversity, possibly representing a new cluster, 'F'. The majority of the EV-C99 strains grouped together as cluster B. In conclusion, this study showed a vast circulation of EVs among Malawian children, with an EV prevalence of 89.9%. Identification of prevalences for species EV-C comparable to our study (38.5%) have only previously been reported in sub-Saharan Africa, and EV-C is rarely found outside of this region. The data found in this study are an important contribution to our current knowledge of EV epidemiology within sub-Saharan Africa.

Recombination in the Evolution of Enterovirus C Species Sub-Group that Contains Types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99

PubMed Central

Smura, Teemu; Blomqvist, Soile; Vuorinen, Tytti; Ivanova, Olga; Samoilovich, Elena; Al-Hello, Haider; Savolainen-Kopra, Carita; Hovi, Tapani; Roivainen, Merja

2014-01-01

Genetic recombination is considered to be a very frequent phenomenon among enteroviruses (Family Picornaviridae, Genus Enterovirus). However, the recombination patterns may differ between enterovirus species and between types within species. Enterovirus C (EV-C) species contains 21 types. In the capsid coding P1 region, the types of EV-C species cluster further into three sub-groups (designated here as A–C). In this study, the recombination pattern of EV-C species sub-group B that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99 was determined using partial 5′UTR and VP1 sequences of enterovirus strains isolated during poliovirus surveillance and previously published complete genome sequences. Several inter-typic recombination events were detected. Furthermore, the analyses suggested that inter-typic recombination events have occurred mainly within the distinct sub-groups of EV-C species. Only sporadic recombination events between EV-C species sub-group B and other EV-C sub-groups were detected. In addition, strict recombination barriers were inferred for CVA-21 genotype C and CVA-24 variant strains. These results suggest that the frequency of inter-typic recombinations, even within species, may depend on the phylogenetic position of the given viruses. PMID:24722726

The calculation of the contributions to low energy e+H2 scattering from sigma u+ and Pion u symmetries using the Kohn variational method

NASA Technical Reports Server (NTRS)

Armour, E. A. G.; Baker, D. J.; Plummer, M.

1990-01-01

Above incident energies of about 2 eV, the contribution to the total cross section in positron+H2 scattering from the sigma g+ symmetry is insufficient to account for the experimental value. Calculations carried out of the lowest partial waves of sigma u+ symmetry and Pion u symmetry using the Kohn variational method are described. The contributions to the total cross section from the two equivalent partial waves of Pion u symmetry significantly reduce the discrepancy with experiment up to incident energies of 4 to 5 eV. Comparisons are made with recent R-matrix calculations performed by Danby and Tennyson.

Specific formation of negative ions from leucine and isoleucine molecules

NASA Astrophysics Data System (ADS)

Papp, Peter; Shchukin, Pavel; Matejčík, Štefan

2010-01-01

Dissociative electron attachment (DEA) to gas phase leucine (Leu) and isoleucine (Ile) molecules was studied using experimental and quantum-chemical methods. The relative partial cross sections for DEA have been measured using crossed electron/molecular beams technique. Supporting ab initio calculations of the structure, energies of neutral molecules, fragments, and negative ions have been carried out at G3MP2 and B3LYP levels in order to interpret the experimental data. Leu and Ile exhibit several common features. The negative ionic fragments from both molecules are formed in the electron energy range from 0 to approximately 14 eV via three resonances (1.2, 5.5, and 8 eV). The relative partial cross sections for DEA Leu and Ile are very similar. The dominant negative ions formed were closed shell negative ions (M-H)- (m/z=130) formed preferentially via low electron energy resonance of 1.23 eV. Additional negative ions with m/z=115, 114, 113, 112, 84, 82, 74, 45, 26, and 17 have been detected.

Absolute partial photoionization cross sections of ethylene

NASA Astrophysics Data System (ADS)

Grimm, F. A.; Whitley, T. A.; Keller, P. R.; Taylor, J. W.

1991-07-01

Absolute partial photoionization cross sections for ionization out of the first four valence orbitals to the X 2B 3u, A 2B 3g, B 2A g and C 2B 2u states of the C 2H 4+ ion are presented as a function of photon energy over the energy range from 12 to 26 eV. The experimental results have been compared to previously published relative partial cross sections for the first two bands at 18, 21 and 24 eV. Comparison of the experimental data with continuum multiple scattering Xα calculations provides evidence for extensive autoionization to the X 2B 3u state and confirms the predicted shape resonances in ionization to the A 2B 3g and B 2A g states. Identification of possible transitions for the autoionizing resonances have been made using multiple scattering transition state calculations on Rydberg excited states.

Isotopic effects in the collinear reactive FHH system

NASA Technical Reports Server (NTRS)

Lepetit, B.; Launay, J. M.; Le Dourneuf, M.

1986-01-01

Exact quantum reaction probabilities for a collinear model of the F + HH, HD, DD and DH reactions on the MV potential energy surface have been computed using hyperspherical coordinates. The results, obtained up to a total energy of 1.8 eV, show three main features: (1) resonances, whose positions and widths are analyzed simply in the hyperspherical formalism; (2) a slowly varying background increasing for FHD, decreasing for FDH, and oscillating for FHH and FDD, whose variations are interpreted by classical dynamics; and (3) partial reaction probabilities revealing decreasing vibrational adiabaticity in the order FHH-FDD-FHD-FDH.

Potential Role of Extracellular Vesicles in the Pathophysiology of Drug Addiction.

PubMed

Rao, P S S; O'Connell, Kelly; Finnerty, Thomas Kyle

2018-01-23

Extracellular vesicles (EVs) are small vesicles secreted by cells and are known to carry sub-cellular components including microRNA, proteins, and lipids. Due to their ability to transport cargo between cells, EVs have been identified as important regulators of various pathophysiological conditions and can therefore influence treatment outcomes. In particular, the significance of microRNAs in EV-mediated cell-cell communication is well-documented. While the influence of EVs and the cargo delivered by EVs has been extensively reviewed in other neurological disorders, the available literature on the potential role of EVs in the pathophysiology of drug addiction has not been reviewed. Hence, in this article, the known effects of commonly abused drugs (ethanol, nicotine, opiates, cocaine, and cannabinoids) on EV secretion have been reviewed. In addition, the potential role of drugs of abuse in affecting the delivery of EV-packaged microRNAs, and the subsequent impact on neuronal health and continued drug dependence, has been discussed.

Microvesicle- and exosome-mediated drug delivery enhances the cytotoxicity of Paclitaxel in autologous prostate cancer cells.

PubMed

Saari, Heikki; Lázaro-Ibáñez, Elisa; Viitala, Tapani; Vuorimaa-Laukkanen, Elina; Siljander, Pia; Yliperttula, Marjo

2015-12-28

Extracellular vesicles (EVs) are naturally occurring membrane particles that mediate intercellular communication by delivering molecular information between cells. In this study, we investigated the effectiveness of two different populations of EVs (microvesicle- and exosome-enriched) as carriers of Paclitaxel to autologous prostate cancer cells. EVs were isolated from LNCaP- and PC-3 prostate cancer cell cultures using differential centrifugation and characterized by electron microscopy, nanoparticle tracking analysis, and Western blot. The uptake of microvesicles and exosomes by the autologous prostate cancer cells was assessed by flow cytometry and confocal microscopy. The EVs were loaded with Paclitaxel and the effectiveness of EV-mediated drug delivery was assessed with viability assays. The distribution of EVs and EV-delivered Paclitaxel in cells was inspected by confocal microscopy. Our main finding was that the loading of Paclitaxel to autologous prostate cancer cell-derived EVs increased its cytotoxic effect. This capacity was independent of the EV population and the cell line tested. Although the EVs without the drug increased cancer cell viability, the net effect of enhanced cytotoxicity remained. Both EV populations delivered Paclitaxel to the recipient cells through endocytosis, leading to the release of the drug from within the cells. The removal of EV surface proteins did not affect exosomes, while the drug delivery mediated by microvesicles was partially inhibited. Cancer cell-derived EVs can be used as effective carriers of Paclitaxel to their parental cells, bringing the drug into the cells through an endocytic pathway and increasing its cytotoxicity. However, due to the increased cell viability, the use of cancer cell-derived EVs must be further investigated before any clinical applications can be designed. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Therapeutic Applications of Extracellular Vesicles: Clinical Promise and Open Questions

PubMed Central

Breakefield, Xandra O.; Leonard, Joshua N.

2015-01-01

This review provides an updated perspective on rapidly proliferating efforts to harness extracellular vesicles (EVs) for therapeutic applications. We summarize current knowledge, emerging strategies, and open questions pertaining to clinical potential and translation. Potentially useful EVs comprise diverse products of various cell types and species. EV components may also be combined with liposomes and nanoparticles to facilitate manufacturing as well as product safety and evaluation. Potential therapeutic cargoes include RNA, proteins, and drugs. Strategic issues considered herein include choice of therapeutic agent, means of loading cargoes into EVs, promotion of EV stability, tissue targeting, and functional delivery of cargo to recipient cells. Some applications may harness natural EV properties, such as immune modulation, regeneration promotion, and pathogen suppression. These properties can be enhanced or customized to enable a wide range of therapeutic applications, including vaccination, improvement of pregnancy outcome, and treatment of autoimmune disease, cancer, and tissue injury. PMID:25292428

Atomistic Simulations of Surface Cross-Slip Nucleation in Face-Centered Cubic Nickel and Copper (Postprint)

DTIC Science & Technology

2013-02-15

molecular dynamics code, LAMMPS [9], developed at Sandia National Laboratory. The simulation cell is a rectangular parallelepiped, with the z-axis...with assigned energies within LAMMPs of greater than 4.42 eV (Ni) or 3.52 eV (Cu) (the energy of atoms in the stacking fault region), the partial...molecular dynamics code LAMMPS , which was developed at Sandia National Laboratory by Dr. Steve Plimpton and co-workers. This work was supported by the

Elastic electron differential cross sections for argon atom in the intermediate energy range from 40 eV to 300 eV

NASA Astrophysics Data System (ADS)

Ranković, Miloš Lj.; Maljković, Jelena B.; Tökési, Károly; Marinković, Bratislav P.

2018-02-01

Measurements and calculations for electron elastic differential cross sections (DCS) of argon atom in the energy range from 40 to 300 eV are presented. DCS have been measured in the crossed beam arrangement of the electron spectrometer with an energy resolution of 0.5 eV and angular resolution of 1.5∘ in the range of scattering angles from 20∘ to 126∘. Both angular behaviour and energy dependence of DCS are obtained in a separate sets of experiments, while the absolute scale is achieved via relative flow method, using helium as a reference gas. All data is corrected for the energy transmission function, changes of primary electron beam current and target pressure, and effective path length (volume correction). DCSs are calculated in relativistic framework by expressing the Mott's cross sections in partial wave expansion. Our results are compared with other available data.

In vitro immunotoxicity assessment of culture-derived extracellular vesicles in human monocytes

PubMed Central

Rosas, Lucia E.; Elgamal, Ola A.; Mo, Xiaokui; Phelps, Mitch A.; Schmittgen, Thomas D.; Papenfuss, Tracey L.

2016-01-01

The potential to engineer extracellular vesicles (EV) that target specific cells and deliver a therapeutic payload has propelled a growing interest in their development as promising therapeutics. These EV are often produced from cultured cells. Very little is known about the interaction of cell culture-derived EV with cells of the immune system and their potential immunomodulatory effects. The present study evaluated potential immunotoxic effects of HEK293T-derived EV on the human monocytic cell lines THP-1 and U937. Incubation of cells with different doses of EV for 16–24 h was followed by assessment of cytotoxicity and cell function by flow cytometry. Changes in cell functionality were evaluated by the capacity of cells to phagocytize fluorescent microspheres. In addition, the internalization of labeled EV in THP-1 and U937 cells was evaluated. Exposure to EV did not affect the viability of THP-1 or U937 cells. Although lower doses of the EV increased phagocytic capacity in both cell lines, phagocytic efficiency of individual cells was not affected by EV exposure at any of the doses evaluated. This study also demonstrated that THP-1 and U937 monocytic cells are highly permissive to EV entry in a dose-response manner. These results suggest that, although HEK293T-derived EV are efficiently internalized by human monocytic cells, they do not exert a cytotoxic effect or alter phagocytic efficiency on the cell lines evaluated. PMID:27075513

Electron-impact ionization of silicon tetrachloride (SiCl4).

PubMed

Basner, R; Gutkin, M; Mahoney, J; Tarnovsky, V; Deutsch, H; Becker, K

2005-08-01

We measured absolute partial cross sections for the formation of various singly charged and doubly charged positive ions produced by electron impact on silicon tetrachloride (SiCl4) using two different experimental techniques, a time-of-flight mass spectrometer (TOF-MS) and a fast-neutral-beam apparatus. The energy range covered was from the threshold to 900 eV in the TOF-MS and to 200 eV in the fast-neutral-beam apparatus. The results obtained by the two different experimental techniques were found to agree very well (better than their combined margins of error). The SiCl3(+) fragment ion has the largest partial ionization cross section with a maximum value of slightly above 6x10(-20) m2 at about 100 eV. The cross sections for the formation of SiCl4(+), SiCl+, and Cl+ have maximum values around 4x10(-20) m2. Some of the cross-section curves exhibit an unusual energy dependence with a pronounced low-energy maximum at an energy around 30 eV followed by a broad second maximum at around 100 eV. This is similar to what has been observed by us earlier for another Cl-containing molecule, TiCl4 [R. Basner, M. Schmidt, V. Tamovsky, H. Deutsch, and K. Becker, Thin Solid Films 374 291 (2000)]. The maximum cross-section values for the formation of the doubly charged ions, with the exception of SiCl3(++), are 0.05x10(-20) m2 or less. The experimentally determined total single ionization cross section of SiCl4 is compared with the results of semiempirical calculations.

Human Rhinovirus 87 and Enterovirus 68 Represent a Unique Serotype with Rhinovirus and Enterovirus Features

PubMed Central

Blomqvist, Soile; Savolainen, Carita; Råman, Laura; Roivainen, Merja; Hovi, Tapani

2002-01-01

It has recently been reported that all but one of the 102 known serotypes of the genus Rhinovirus segregate into two genetic clusters (C. Savolainen, S. Blomqvist, M. N. Mulders, and T. Hovi, J. Gen. Virol. 83:333-340, 2002). The only exception is human rhinovirus 87 (HRV87). Here we demonstrate that HRV87 is genetically and antigenically highly similar to enterovirus 68 (EV68) and is related to EV70, the other member of human enterovirus group D. The partial nucleotide sequences of the 5′ untranslated region, capsid regions VP4/VP2 and VP1, and the 3D RNA polymerase gene of the HRV87 prototype strain F02-3607 Corn showed 97.3, 97.8, 95.2, and 95.9% identity to the corresponding regions of EV68 prototype strain Fermon. The amino acid identities were 100 and 98.1% for the products of the two capsid regions and 97.9% for 3D RNA polymerase. Antigenic cross-reaction between HRV87 and EV68 was indicated by microneutralization with monotypic antisera. Phylogenetic analysis showed definite clustering of HRV87 and EV68 with EV70 for all sequences examined. Both HRV87 and EV68 were shown to be acid sensitive by two different assays, while EV70 was acid resistant, which is typical of enteroviruses. The cytopathic effect induced by HRV87 or EV68 was inhibited by monoclonal antibodies to the decay-accelerating factor known to be the receptor of EV70. We conclude that HRV87 and EV68 are strains of the same picornavirus serotype presenting features of both rhinoviruses and enteroviruses. PMID:12409401

Ab initio molecular dynamics simulations of low energy recoil events in MgO

DOE PAGES

Petersen, B. A.; Liu, B.; Weber, W. J.; ...

2017-01-11

In this paper, low-energy recoil events in MgO are studied using ab initio molecular dynamics simulations to reveal the dynamic displacement processes and final defect configurations. Threshold displacement energies, E d, are obtained for Mg and O along three low-index crystallographic directions, [100], [110], and [111]. The minimum values for E d are found along the [110] direction consisting of the same element, either Mg or O atoms. Minimum threshold values of 29.5 eV for Mg and 25.5 eV for O, respectively, are suggested from the calculations. For other directions, the threshold energies are considerably higher, 65.5 and 150.0 eVmore » for O along [111] and [100], and 122.5 eV for Mg along both [111] and [100] directions, respectively. These results show that the recoil events in MgO are partial-charge transfer assisted processes where the charge transfer plays an important role. Finally, there is a similar trend found in other oxide materials, where the threshold displacement energy correlates linearly with the peak partial-charge transfer, suggesting this behavior might be universal in ceramic oxides.« less

Mother's Milk: A Purposeful Contribution to the Development of the Infant Microbiota and Immunity.

PubMed

Le Doare, Kirsty; Holder, Beth; Bassett, Aisha; Pannaraj, Pia S

2018-01-01

Breast milk is the perfect nutrition for infants, a result of millions of years of evolution. In addition to providing a source of nutrition, breast milk contains a diverse array of microbiota and myriad biologically active components that are thought to guide the infant's developing mucosal immune system. It is believed that bacteria from the mother's intestine may translocate to breast milk and dynamically transfer to the infant. Such interplay between mother and her infant is a key to establishing a healthy infant intestinal microbiome. These intestinal bacteria protect against many respiratory and diarrheal illnesses, but are subject to environmental stresses such as antibiotic use. Orchestrating the development of the microbiota are the human milk oligosaccharides (HMOs), the synthesis of which are partially determined by the maternal genotype. HMOs are thought to play a role in preventing pathogenic bacterial adhesion though multiple mechanisms, while also providing nutrition for the microbiome. Extracellular vesicles (EVs), including exosomes, carry a diverse cargo, including mRNA, miRNA, and cytosolic and membrane-bound proteins, and are readily detectable in human breast milk. Strongly implicated in cell-cell signaling, EVs could therefore may play a further role in the development of the infant microbiome. This review considers the emerging role of breast milk microbiota, bioactive HMOs, and EVs in the establishment of the neonatal microbiome and the consequent potential for modulation of neonatal immune system development.

Positron scattering from molecular hydrogen

NASA Astrophysics Data System (ADS)

Machacek, J. R.; Anderson, E. K.; Makochekanwa, C.; Buckman, S. J.; Sullivan, J. P.

2013-10-01

We present results for total and partial cross sections for positron scattering from H2. The total scattering and positronium formation cross sections are reported between 0.5 and 200 eV. Total quasielastic and inelastic scattering cross sections are reported for energies between the positronium formation threshold and 50 eV, with quasielastic differential scattering cross sections reported at 1, 3, 5, 7, and 10 eV. Our results are compared with previous work, both experimental and theoretical, with particular attention paid to the region below the positronium formation threshold, where there are apparent discrepancies in previous work. A discussion of possible reasons for discrepancies between this and previous work is presented, including a focus on known systematic effects in the experimental results.

Increased liver-specific proteins in circulating extracellular vesicles as potential biomarkers for drug- and alcohol-induced liver injury

PubMed Central

Cho, Young-Eun; Im, Eun-Ju; Moon, Pyong-Gon; Mezey, Esteban; Song, Byoung-Joon; Baek, Moon-Chang

2017-01-01

Drug- and alcohol-induced liver injury are a leading cause of liver failure and transplantation. Emerging evidence suggests that extracellular vesicles (EVs) are a source of biomarkers because they contain unique proteins reflecting the identity and tissue-specific origin of the EV proteins. This study aimed to determine whether potentially hepatotoxic agents, such as acetaminophen (APAP) and binge alcohol, can increase the amounts of circulating EVs and evaluate liver-specific EV proteins as potential biomarkers for liver injury. The circulating EVs, isolated from plasma of APAP-exposed, ethanol-fed mice, or alcoholic hepatitis patients versus normal control counterparts, were characterized by proteomics and biochemical methods. Liver specific EV proteins were analyzed by immunoblots and ELISA. The amounts of total and liver-specific proteins in circulating EVs from APAP-treated mice significantly increased in a dose- and time-dependent manner. Proteomic analysis of EVs from APAP-exposed mice revealed that the amounts of liver-specific and/or hepatotoxic proteins were increased compared to those of controls. Additionally, the increased protein amounts in EVs following APAP exposure returned to basal levels when mice were treated with N-acetylcysteine or glutathione. Similar results of increased amounts and liver-specific proteins in circulating EVs were also observed in mice exposed to hepatotoxic doses of thioacetamide or d-galactosamine but not by non-hepatotoxic penicillin or myotoxic bupivacaine. Additionally, binge ethanol exposure significantly elevated liver-specific proteins in circulating EVs from mice and alcoholics with alcoholic hepatitis, compared to control counterparts. These results indicate that circulating EVs in drug- and alcohol-mediated hepatic injury contain liver-specific proteins that could serve as specific biomarkers for hepatotoxicity. PMID:28225807

Electronic and magnetic properties of Zn1-xFexSe alloys

NASA Astrophysics Data System (ADS)

Khatta, Swati; Tripathi, S. K.; Prakash, Satya

2017-12-01

The spin polarized density functional theory along with self consistent plane wave pseudopotential method is used to investigate electronic and magnetic properties of ternary Zn1-xFexSe alloys with x = 0.125, 0.25, 0.5 and 0.75. The exchange-correlation potential treated within generalized gradient approximation is used. The calculated spin-polarized band structures, partial and total density of states reveal that Zn0.875Fe0.125Se and Zn0.75Fe0.25Se exhibit half metallic ferromagnetic characteristics and Zn0.50Fe0.50Se is nearly half metallic in nature. The half metallic band gaps for x = 0.125 and 0.25 are 0.69 and 0.39 eV respectively, while the corresponding band gaps are 0.86 and 0.81 eV. The p-d hybridization reduces the magnetic moment of Fe atoms from its free space charge value of 4 μB and induces the small magnetic moments on Zn and Se sites. The results are compared with available experimental data.

Ab initio study of aspirin adsorption on single-walled carbon and carbon nitride nanotubes

NASA Astrophysics Data System (ADS)

Lee, Yongju; Kwon, Dae-Gyeon; Kim, Gunn; Kwon, Young-Kyun

We use ab intio density functional theory to investigate the adsorption properties of acetylsalicylic acid or aspirin on a (10, 0) carbon nanotube (CNT) and a (8, 0) triazine-based graphitic carbon nitride nanotube (CNNT). It is found that an aspirin molecule binds stronger to the CNNT with its adsorption energy of 0.67 eV than to the CNT with 0.51 eV. The stronger adsorption energy on the CNNT is ascribed to the high reactivity of its N atoms with high electron affinity. The CNNT exhibits local electric dipole moments, which cause strong charge redistribution in the aspirin molecule adsorbed on the CNNT than on the CNT. We also explore the influence of an external electric field on the adsorption properties of aspirin on these nanotubes by examining the modifications in their electronic band structures, partial densities of states, and charge distributions. It is found that an electric field applied along a particular direction induces aspirin molecular states in the in-gap region of the CNNT implying a potential application of aspirin detection.

Human enterovirus D68 in clinical and sewage samples in Israel.

PubMed

Weil, Merav; Mandelboim, Michal; Mendelson, Ella; Manor, Yossi; Shulman, Lester; Ram, Daniela; Barkai, Galia; Shemer, Yonat; Wolf, Dana; Kra-Oz, Zipi; Weiss, Leah; Pando, Rakefet; Hindiyeh, Musa; Sofer, Danit

2017-01-01

Since mid-August 2014, North America experienced a wide outbreak of Enterovirus D68 (EV-D68) associated with severe respiratory illness in children. Several other countries also reported cases of EV-D68 in 2014. The aim of this study was to determine whether EV-D68 circulated in Israel in 2014, caused severe respiratory illness in children and was the causative agent of Acute Flaccid Paralysis. Archived clinical respiratory samples from a cohort of 710 hospitalized pediatric patient's (<10years old) with respiratory illness were screened for clade B specific EV-D68 by real-time PCR. The patients were seen at four medical centers covering the entire country between August and November 2014. We also evaluated 49 patient stool samples from 26 AFP cases during 2014 for presence of EV-D68. In addition, RNA from sewage samples collected throughout Israel during the same study period was also tested for EV-D68. Partial VP1 sequencing was performed on all positive samples. Of the 710 clinical samples evaluated, 7 (1%) were positive for EV-D68. Two patients were from the central part of Israel, while the rest was from the southern part. The majority of the patients did not have any underlying disease. Not only that, but, none of the 26 suspected AFP cases had EV-D68 nucleic acid in their stool samples. EV-D68 RNA was detected in 9 out of 93 sewage samples, mainly from Southern Israel. Sequence analysis of EV-D68 VP1 gene from both sewage and clinical samples indicated that the Israeli EV-D68 RNA belonged to Clade B which was genetically similar to 2014 circulating European and North American EV-D68 virus. EV-D68 circulated in Israel during the 2014 summer-fall season and caused hospitalization of a small percent of the patients with respiratory illness. Copyright © 2016 Elsevier B.V. All rights reserved.

A density functional study of atomic hydrogen and oxygen chemisorption on the relaxed (0001) surface of double hexagonal close packed americium

NASA Astrophysics Data System (ADS)

Dholabhai, P. P.; Atta-Fynn, R.; Ray, A. K.

2008-02-01

Ab initio total energy calculations within the framework of density functional theory have been performed for atomic hydrogen and oxygen chemisorption on the (0001) surface of double hexagonal packed americium using a full-potential all-electron linearized augmented plane wave plus local orbitals method. Chemisorption energies were optimized with respect to the distance of the adatom from the relaxed surface for three adsorption sites, namely top, bridge, and hollow hcp sites, the adlayer structure corresponding to coverage of a 0.25 monolayer in all cases. Chemisorption energies were computed at the scalar-relativistic level (no spin-orbit coupling NSOC) and at the fully relativistic level (with spin-orbit coupling SOC). The two-fold bridge adsorption site was found to be the most stable site for O at both the NSOC and SOC theoretical levels with chemisorption energies of 8.204 eV and 8.368 eV respectively, while the three-fold hollow hcp adsorption site was found to be the most stable site for H with chemisorption energies of 3.136 eV at the NSOC level and 3.217 eV at the SOC level. The respective distances of the H and O adatoms from the surface were found to be 1.196 Åand 1.164 Å. Overall our calculations indicate that chemisorption energies in cases with SOC are slightly more stable than the cases with NSOC in the 0.049 0.238 eV range. The work functions and net magnetic moments respectively increased and decreased in all cases compared with the corresponding quantities of bare dhcp Am (0001) surface. The partial charges inside the muffin-tins, difference charge density distributions, and the local density of states have been used to analyze the Am-adatom bond interactions in detail. The implications of chemisorption on Am 5f electron localization-delocalization are also discussed.

Extracellular vesicles at the cross-line between basic science and clinical needs.

PubMed

Sasso, Luana; Hosamuddin, Huma; Emanueli, Costanza

2017-01-01

MiRNAs are small noncoding RNAs vital for protein regulation and gene expression. Since their discovery in the early nineties, many of their intracellular roles have been characterized. However, it is only recently that EVs loaded with miRNAs and other molecular types have started to be appreciated for their substantial involvement in cell-to-cell communication and signaling in physiological and pathological processes. EVs cell-to-cell signaling functions are complex and largely unknown, which still hampers the direct use of endogenous engineered EVs as therapeutics. However, ad hoc engineered synthetic EVs could represent new therapeutics. The potential of EV-inspired delivery carriers has now attracted the interest of the pharmaceutical industry and has challenged drug delivery researchers with new questions. This review will focus on EVs and EV-inspired drug delivery carriers, on their potential and on the challenges involved in the use of EV-inspired drug delivery systems. © 2016 John Wiley & Sons Ltd.

Extracellular vesicles derived from mesenchymal stromal cells: a therapeutic option in respiratory diseases?

PubMed

Abreu, Soraia C; Weiss, Daniel J; Rocco, Patricia R M

2016-04-14

Extracellular vesicles (EVs) are plasma membrane-bound fragments released from several cell types, including mesenchymal stromal cells (MSCs), constitutively or under stimulation. EVs derived from MSCs and other cell types transfer molecules (such as DNA, proteins/peptides, mRNA, microRNA, and lipids) and/or organelles with reparative and anti-inflammatory properties to recipient cells. The paracrine anti-inflammatory effects promoted by MSC-derived EVs have attracted significant interest in the regenerative medicine field, including for potential use in lung injuries. In the present review, we describe the characteristics, biological activities, and mechanisms of action of MSC-derived EVs. We also review the therapeutic potential of EVs as reported in relevant preclinical models of acute and chronic respiratory diseases, such as pneumonia, acute respiratory distress syndrome, asthma, and pulmonary arterial hypertension. Finally, we discuss possible approaches for potentiating the therapeutic effects of MSC-derived EVs so as to enable use of this therapy in clinical practice.

Extracellular vesicles from parasitic helminths and their potential utility as vaccines.

PubMed

Mekonnen, Gebeyaw Getnet; Pearson, Mark; Loukas, Alex; Sotillo, Javier

2018-03-01

Helminths are multicellular parasites affecting nearly three billion people worldwide. To orchestrate a parasitic existence, helminths secrete different molecules, either in soluble form or contained within extracellular vesicles (EVs). EVs are secreted by most cell types and organisms, and have varied roles in intercellular communication, including immune modulation and pathogenesis. Areas covered: In this review, we describe the nucleic acid and proteomic composition of EVs from helminths, with a focus on the protein vaccine candidates present on the EV surface membrane, and discuss the potential utility of helminth EVs and their constituent proteins in the fight against helminth infections. Expert commentary: A significant number of proteins present in helminth-secreted EVs are known vaccine candidates. The characterization of helminth EV proteomes will shed light on host-pathogen interactions, facilitate the discovery of new diagnostic biomarkers, and provide a novel approach for the development of new control measures against helminth infections.

Importance of indoor dust biological ultrafine particles in the pathogenesis of chronic inflammatory lung diseases

PubMed Central

Kim, Yoon-Keun; Kang, Tae Soo; Kim, You-Young

2017-01-01

The role of infectious agents in the etiology of inflammatory diseases once believed to be non-infectious is increasingly being recognized. Many bacterial components in the indoor dust can evoke inflammatory lung diseases. Bacteria secrete nanometer-sized vesicles into the extracellular milieu, so-called extracellular vesicles (EV). which are pathophysiologically related to inflammatory diseases. Microbiota compositions in the indoor dust revealed the presence of both Gram-negative and Gram-positive bacteria. Escherichia coli is a model organism of Gram-negative Enterobacteriaceae. The repeated inhalation of E. coli-derived EVs caused neutrophilic inflammation and emphysema in a dose-dependent manner. The emphysema induced by E. coli-derived EVs was partially eliminated by the absence of Interferon-gamma or interleukin-17, suggesting that Th1 and/or Th17 cell responses are important in the emphysema development. Meanwhile, the repeated inhalation of Staphylococcus aureus-derived EVs did not induce emphysema, although they induced neutrophilic inflammation in the lung. In terms of microbial EV compositions in the indoor dust, genera Pseudomonas, Acinetobacter, Enterobacter, and Staphylococcus were dominant. As for the clinical significance of sensitization to EVs in the indoor dust, EV sensitization was closely associated with asthma, chronic obstructive pulmonary disorder (COPD), and lung cancer. These data indicate that biological ultrafine particles in the indoor dust, which are mainly composed of microbial EVs, are important in the pathogenesis of chronic lung diseases associated with neutrophilic inflammation. Taken together, microbial EVs in the indoor dust are an important diagnostic and therapeutic target for the control of chronic lung diseases, such as asthma, COPD, and lung cancer. PMID:29161804

Importance of indoor dust biological ultrafine particles in the pathogenesis of chronic inflammatory lung diseases.

PubMed

Yang, Jinho; Kim, Yoon-Keun; Kang, Tae Soo; Jee, Young-Koo; Kim, You-Young

2017-01-01

The role of infectious agents in the etiology of inflammatory diseases once believed to be non-infectious is increasingly being recognized. Many bacterial components in the indoor dust can evoke inflammatory lung diseases. Bacteria secrete nanometer-sized vesicles into the extracellular milieu, so-called extracellular vesicles (EV). which are pathophysiologically related to inflammatory diseases. Microbiota compositions in the indoor dust revealed the presence of both Gram-negative and Gram-positive bacteria. Escherichia coli is a model organism of Gram-negative Enterobacteriaceae. The repeated inhalation of E. coli-derived EVs caused neutrophilic inflammation and emphysema in a dose-dependent manner. The emphysema induced by E. coli-derived EVs was partially eliminated by the absence of Interferon-gamma or interleukin-17, suggesting that Th1 and/or Th17 cell responses are important in the emphysema development. Meanwhile, the repeated inhalation of Staphylococcus aureus-derived EVs did not induce emphysema, although they induced neutrophilic inflammation in the lung. In terms of microbial EV compositions in the indoor dust, genera Pseudomonas, Acinetobacter, Enterobacter, and Staphylococcus were dominant. As for the clinical significance of sensitization to EVs in the indoor dust, EV sensitization was closely associated with asthma, chronic obstructive pulmonary disorder (COPD), and lung cancer. These data indicate that biological ultrafine particles in the indoor dust, which are mainly composed of microbial EVs, are important in the pathogenesis of chronic lung diseases associated with neutrophilic inflammation. Taken together, microbial EVs in the indoor dust are an important diagnostic and therapeutic target for the control of chronic lung diseases, such as asthma, COPD, and lung cancer.

First Characterization of Human Amniotic Fluid Stem Cell Extracellular Vesicles as a Powerful Paracrine Tool Endowed with Regenerative Potential.

PubMed

Balbi, Carolina; Piccoli, Martina; Barile, Lucio; Papait, Andrea; Armirotti, Andrea; Principi, Elisa; Reverberi, Daniele; Pascucci, Luisa; Becherini, Pamela; Varesio, Luigi; Mogni, Massimo; Coviello, Domenico; Bandiera, Tiziano; Pozzobon, Michela; Cancedda, Ranieri; Bollini, Sveva

2017-05-01

Human amniotic fluid stem cells (hAFS) have shown a distinct secretory profile and significant regenerative potential in several preclinical models of disease. Nevertheless, little is known about the detailed characterization of their secretome. Herein we show for the first time that hAFS actively release extracellular vesicles (EV) endowed with significant paracrine potential and regenerative effect. c-KIT + hAFS were isolated from leftover samples of amniotic fluid from prenatal screening and stimulated to enhance EV release (24 hours 20% O 2 versus 1% O 2 preconditioning). The capacity of the c-KIT + hAFS-derived EV (hAFS-EV) to induce proliferation, survival, immunomodulation, and angiogenesis were investigated in vitro and in vivo. The hAFS-EV regenerative potential was also assessed in a model of skeletal muscle atrophy (HSA-Cre, Smn F7/F7 mice), in which mouse AFS transplantation was previously shown to enhance muscle strength and survival. hAFS secreted EV ranged from 50 up to 1,000 nm in size. In vitro analysis defined their role as biological mediators of regenerative, paracrine effects while their modulatory role in decreasing skeletal muscle inflammation in vivo was shown for the first time. Hypoxic preconditioning significantly induced the enrichment of exosomes endowed with regenerative microRNAs within the hAFS-EV. In conclusion, this is the first study showing that c-KIT + hAFS dynamically release EV endowed with remarkable paracrine potential, thus representing an appealing tool for future regenerative therapy. Stem Cells Translational Medicine 2017;6:1340-1355. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Nanosized UCMSC-derived extracellular vesicles but not conditioned medium exclusively inhibit the inflammatory response of stimulated T cells: implications for nanomedicine.

PubMed

Monguió-Tortajada, Marta; Roura, Santiago; Gálvez-Montón, Carolina; Pujal, Josep Maria; Aran, Gemma; Sanjurjo, Lucía; Franquesa, Marcel la; Sarrias, Maria-Rosa; Bayes-Genis, Antoni; Borràs, Francesc E

2017-01-01

Undesired immune responses have drastically hampered outcomes after allogeneic organ transplantation and cell therapy, and also lead to inflammatory diseases and autoimmunity. Umbilical cord mesenchymal stem cells (UCMSCs) have powerful regenerative and immunomodulatory potential, and their secreted extracellular vesicles (EVs) are envisaged as a promising natural source of nanoparticles to increase outcomes in organ transplantation and control inflammatory diseases. However, poor EV preparations containing highly-abundant soluble proteins may mask genuine vesicular-associated functions and provide misleading data. Here, we used Size-Exclusion Chromatography (SEC) to successfully isolate EVs from UCMSCs-conditioned medium. These vesicles were defined as positive for CD9, CD63, CD73 and CD90, and their size and morphology characterized by NTA and cryo-EM. Their immunomodulatory potential was determined in polyclonal T cell proliferation assays, analysis of cytokine profiles and in the skewing of monocyte polarization. In sharp contrast to the non-EV containing fractions, to the complete conditioned medium and to ultracentrifuged pellet, SEC-purified EVs from UCMSCs inhibited T cell proliferation, resembling the effect of parental UCMSCs. Moreover, while SEC-EVs did not induce cytokine response, the non-EV fractions, conditioned medium and ultracentrifuged pellet promoted the secretion of pro-inflammatory cytokines by polyclonally stimulated T cells and supported Th17 polarization. In contrast, EVs did not induce monocyte polarization, but the non-EV fraction induced CD163 and CD206 expression and TNF-α production in monocytes. These findings increase the growing evidence confirming that EVs are an active component of MSC's paracrine immunosuppressive function and affirm their potential for therapeutics in nanomedicine. In addition, our results highlight the importance of well-purified and defined preparations of MSC-derived EVs to achieve the immunosuppressive effect.

Extracellular vesicles for personalized therapy decision support in advanced metastatic cancers and its potential impact for prostate cancer.

PubMed

Soekmadji, Carolina; Corcoran, Niall M; Oleinikova, Irina; Jovanovic, Lidija; Ramm, Grant A; Nelson, Colleen C; Jenster, Guido; Russell, Pamela J

2017-10-01

The use of circulating tumor cells (CTCs) and circulating extracellular vesicles (EVs), such as exosomes, as liquid biopsy-derived biomarkers for cancers have been investigated. CTC enumeration using the CellSearch based platform provides an accurate insight on overall survival where higher CTC counts indicate poor prognosis for patients with advanced metastatic cancer. EVs provide information based on their lipid, protein, and nucleic acid content and can be isolated from biofluids and analyzed from a relatively small volume, providing a routine and non-invasive modality to monitor disease progression. Our pilot experiment by assessing the level of two subpopulations of small EVs, the CD9 positive and CD63 positive EVs, showed that the CD9 positive EV level is higher in plasma from patients with advanced metastatic prostate cancer with detectable CTCs. These data show the potential utility of a particular EV subpopulation to serve as biomarkers for advanced metastatic prostate cancer. EVs can potentially be utilized as biomarkers to provide accurate genotypic and phenotypic information for advanced prostate cancer, where new strategies to design a more personalized therapy is currently the focus of considerable investigation. © 2017 Wiley Periodicals, Inc.

The soft X-ray diffuse background

NASA Technical Reports Server (NTRS)

Mccammon, D.; Burrows, D. N.; Sanders, W. T.; Kraushaar, W. L.

1982-01-01

Maps of the diffuse X-ray background intensity covering essentially the entire sky with approx. 7 deg spatial resolution are presented for seven energy bands. The data were obtained on a series of ten sounding rocket flights conducted over a seven-year period. The different nature of the spatial distributions in different bands implies at least three distinct origins for the diffuse X-rays, none of which is well-understood. At energies or approx. 2000 eV, an isotropic and presumably extraglalactic 500 and 1000 eV, an origin which is at least partially galactic seems called for. At energies 284 eV, the observed intensity is anticorrelated with neutral hydrogen column density, but we find it unlikely that this anticorrelation is simply due to absorption of an extragalactic or halo source.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osada, Motoki; Nishio, Kazunori; Hwang, Harold Y.

Here, we investigate the growth phase diagram of pseudobrookite Fe 2TiO 5 epitaxial thin films on LaAlO 3 (001) substrates using pulsed laser deposition. Control of the oxygen partial pressure and temperature during deposition enabled selective stabilization of (100)- and (230)-oriented films. In this regime, we find an optical gap of 2.1 eV and room temperature resistivity in the range of 20–80 Ω cm, which are significantly lower than α-Fe 2O 3, making Fe 2TiO 5 potentially an ideal inexpensive visible-light harvesting semiconductor. These results provide a basis to incorporate Fe 2TiO 5 in oxide heterostructures for photocatalytic and photoelectrochemicalmore » applications.« less

EMI Measurement and Mitigation Testing for the ARPA Hybrid Electric Vehicle Program

DTIC Science & Technology

1996-08-27

communication range is reduced, computers malfunction, or monitoring systems fail. Various electric vehicles ( EVs ) were measured to evaluate their...electric vehicles ( EVs ) were measured to evaluate their potential EMI emissions when used in today’s hostile commercial electromagnetic environment...monitoring systems fail. Various electric vehicles ( EVs ) were measured to evaluate their potential EMI emissions when used in today’s hostile commercial

Extracellular Vesicles as Therapeutic Tools in Cardiovascular Diseases

PubMed Central

Fleury, Audrey; Martinez, Maria Carmen; Le Lay, Soazig

2014-01-01

Extracellular vesicles (EVs), including microvesicles (MVs) and exosomes, are small vesicles secreted from a wide variety of cells. Whereas MVs are particles released by the outward budding of the plasma membrane, exosomes are derived from endocytic compartments. Secretion of EVs can be enhanced by specific stimuli, and increased plasma circulating levels of EVs have been correlated with pathophysiological situations. MVs, already present in the blood of healthy individuals, are considerably elevated in several cardiovascular diseases associated with inflammation, suggesting that they can mediate deleterious effects such as endothelial dysfunction or thrombosis. Nonetheless, very recent studies also demonstrate that MVs may act as biological information vectors transferring proteins or genetic material to maintain cell homeostasis, favor cell repair, or even promote angiogenesis. Additionally, exosomes have also been shown to have pro-angiogenic and cardio-protective properties. These beneficial effects, therefore, reveal the potential therapeutical use of EVs in the field of cardiovascular medicine and regenerative therapy. In this review, we will provide an update of cellular processes modulated by EVs of specific interest in the treatment of cardiovascular pathologies. A special focus will be made on the morphogen sonic hedgehog (Shh) associated with EVs (EVsShh+), which have been shown to mediate many pro-angiogenic effects. In addition to offer a potential source of cardiovascular markers, therapeutical potential of EVs reveal exciting opportunities to deliver specific agents by non-immunogenic means to cardiovascular system. PMID:25136343

Electronic states in oxidized NaxCoO2 as revealed by X-ray absorption spectroscopy coupled with ab initio calculation

NASA Astrophysics Data System (ADS)

Niwa, Hideharu; Higashiyama, Kazuyuki; Amaha, Kaoru; Kobayashi, Wataru; Moritomo, Yutaka

2018-04-01

Layered cobalt oxides are promising cathode materials for sodium ion secondary batteries (SIBs). By combined study of the X-ray absorption spectroscopy (XAS) around the O K-edge and ab initio calculation, we investigated the electronic state of the NaxCoO2 with different oxidization state, i.e, in O3-Na0.91CoO2 (CoO2-0.91) and P2-Na0.66CoO2 (CoO2-0.66). The O K-edge spectra in the pre-edge (529-536 eV) region shows significant change with oxidization of NaxCoO2. In O3-Na0.91CoO2, the spectra shows an intense band (B band) at 531 eV. In P2-Na0.66CoO2, the spectral weight of the B band increases and a new band (A band) appears at 530 eV. These spectral changes are qualitatively reproduced by the calculated partial density of states (pDOSs) of O3-NaCoO2 and P2-Na1/2CoO2. These results indicate that the electrons are partially removed from the O 2p state with oxidization of NaxCoO2.

Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida

USGS Publications Warehouse

Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard

2012-01-01

Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

Laboratory investigation and phylogenetic analysis of enteroviruses involved in an aseptic meningitis outbreak in Greece during the summer of 2007.

PubMed

Logotheti, Maria; Pogka, Vasiliki; Horefti, Elina; Papadakos, Konstantinos; Giannaki, Maria; Pangalis, Anastasia; Sgouras, Dionyssios; Mentis, Andreas

2009-11-01

Aseptic meningitis is the most commonly observed CNS infection and is mainly attributed to Non-Polio Enteroviruses (EV). Identification and genetic analysis of the EV involved in the recent aseptic meningitis outbreak which occurred in Greece, during the summer of 2007. In total, 213 CSF and faecal samples were examined for EV presence by culture, while enteroviral RNA detection was performed by nucleic acid sequence-based amplification assay (NASBA). EV strains were typed by seroneutralization, as well as nested RT-PCR followed by VP1-2A gene partial sequencing. Phylogenetic analysis was carried out for the identification of the genetic relatedness among the isolated EV strains. EV detection rate in CSF and faecal samples was 43.9% and 70.8%, respectively. EV serotyping and VP1 region analysis revealed the predominance of echovirus 4 (ECV4) serotype and the circulation of ECV6, 9, 14, 25, Coxsackie A6, A15, A24 and Coxsackie B1 serotypes. All ECV4 isolates presented a 98.7% similarity in nucleotide sequence, with a Spanish ECV4 strain, isolated during a meningitis outbreak in 2006. It is the first time that ECV4 is associated with an aseptic meningitis outbreak in Greece, during which 9 different EV serotypes were co-circulating. All Greek ECV4 isolates were closely related to the Spanish ECV4 strain. Genetic analysis of the VP1 gene can significantly contribute to the revelation of the endemic EV strains circulation pattern and their phylogenetic relationship with enteroviruses involved in epidemics of distant geographical areas at different time periods.

Ab initio full-potential fully relativistic study of atomic carbon, nitrogen, and oxygen chemisorption on the (111) surface of δ-Pu

NASA Astrophysics Data System (ADS)

Atta-Fynn, Raymond; Ray, Asok K.

2007-05-01

First-principles total-energy calculations within the framework of generalized gradient approximation to density-functional theory have been performed for atomic carbon, nitrogen, and oxygen chemisorption on the (111) surface of δ-Pu . The full-potential all-electron linearized augmented plane wave plus local orbitals method with the Perdew-Burke-Ernzerhof exchange-correlation functional has been employed. Chemisorption energies have been optimized with respect to the distance of the adatom from the Pu surface for four adsorption sites, namely, the top, bridge, hollow fcc, and hollow hcp sites, with the adlayer structure corresponding to a coverage of 0.50 of a monolayer in all cases. Computations were carried out at two theoretical levels, one without spin-orbit coupling (NSOC) and one with spin-orbit coupling (SOC). For NSOC calculations, the hollow fcc adsorption site was found to be the most stable site for C and N with chemisorption energies of 6.272 and 6.504eV , respectively, while the hollow hcp adsorption site was found to be the most stable site for O with chemisorption energy of 8.025eV . For SOC calculations, the hollow fcc adsorption site was found to be the most stable site in all cases with chemisorption energies for C, N, and O being 6.539, 6.714, and 8.2eV , respectively. The respective distances of the C, N, and O adatoms from the surface were found to be 1.16, 1.08, and 1.25Å . Our calculations indicate that SOC has negligible effect on the chemisorption geometries, but energies with SOC are more stable than the cases with NSOC within a range of 0.05-0.27eV . The work function and net magnetic moments, respectively, increased and decreased in all cases upon chemisorption compared with the bare δ-Pu (111) surface. The partial charges inside the muffin tins, difference charge-density distributions, and the local density of states have been used to analyze the Pu-adatom bond interactions.

Extracellular Vesicles: How the External and Internal Environment Can Shape Cell-To-Cell Communication.

PubMed

Neven, Kristof Y; Nawrot, Tim S; Bollati, Valentina

2017-03-01

To summarize the scientific evidence regarding the effects of environmental exposures on extracellular vesicle (EV) release and their contents. As environmental exposures might influence the aging phenotype in a very strict way, we will also report the role of EVs in the biological aging process. EV research is a new and quickly developing field. With many investigations conducted so far, only a limited number of studies have explored the potential role EVs play in the response and adaptation to environmental stimuli. The investigations available to date have identified several exposures or lifestyle factors able to modify EV trafficking including air pollutants, cigarette smoke, alcohol, obesity, nutrition, physical exercise, and oxidative stress. EVs are a very promising tool, as biological fluids are easily obtainable biological media that, if successful in identifying early alterations induced by the environment and predictive of disease, would be amenable to use for potential future preventive and diagnostic applications.

Mother’s Milk: A Purposeful Contribution to the Development of the Infant Microbiota and Immunity

PubMed Central

Le Doare, Kirsty; Holder, Beth; Bassett, Aisha; Pannaraj, Pia S.

2018-01-01

Breast milk is the perfect nutrition for infants, a result of millions of years of evolution. In addition to providing a source of nutrition, breast milk contains a diverse array of microbiota and myriad biologically active components that are thought to guide the infant’s developing mucosal immune system. It is believed that bacteria from the mother’s intestine may translocate to breast milk and dynamically transfer to the infant. Such interplay between mother and her infant is a key to establishing a healthy infant intestinal microbiome. These intestinal bacteria protect against many respiratory and diarrheal illnesses, but are subject to environmental stresses such as antibiotic use. Orchestrating the development of the microbiota are the human milk oligosaccharides (HMOs), the synthesis of which are partially determined by the maternal genotype. HMOs are thought to play a role in preventing pathogenic bacterial adhesion though multiple mechanisms, while also providing nutrition for the microbiome. Extracellular vesicles (EVs), including exosomes, carry a diverse cargo, including mRNA, miRNA, and cytosolic and membrane-bound proteins, and are readily detectable in human breast milk. Strongly implicated in cell–cell signaling, EVs could therefore may play a further role in the development of the infant microbiome. This review considers the emerging role of breast milk microbiota, bioactive HMOs, and EVs in the establishment of the neonatal microbiome and the consequent potential for modulation of neonatal immune system development. PMID:29599768

Protective effect of enterovirus‑71 (EV71) virus‑like particle vaccine against lethal EV71 infection in a neonatal mouse model.

PubMed

Cao, Lei; Mao, Fengfeng; Pang, Zheng; Yi, Yao; Qiu, Feng; Tian, Ruiguang; Meng, Qingling; Jia, Zhiyuan; Bi, Shengli

2015-08-01

Enterovirus-71 (EV71) is a viral pathogen that causes severe cases of hand, foot and mouth disease (HFMD) among young children, with significant mortality. Effective vaccines against HFMD are urgently required. Several EV71 virus-like particle (VLP) vaccine candidates were found to be protective in the neonatal mouse EV71 challenge model. However, to what extent the VLP vaccine protects susceptible organs against EV71 infection in vivo has remained elusive. In the present study, the comprehensive immunogenicity of a potential EV71 vaccine candidate based on VLPs was evaluated in a neonatal mouse model. Despite lower levels of neutralizing antibodies to EV71 in the sera of VLP-immunized mice compared with those in mice vaccinated with inactivated EV71, the VLP-based vaccine was shown to be able to induce immunoglobulin (Ig)G and IgA memory-associated cellular immune responses to EV71. Of note, the EV71 VLP vaccine candidate was capable of inhibiting viral proliferation in cardiac muscle, skeletal muscle, lung and intestine of immunized mice and provided effective protection against the pathological damage caused by viral attack. In particular, the VLP vaccine was able to inhibit the transportation of EV71 from the central nervous system to the muscle tissue and greatly protected muscle tissue from infection, along with recovery from the viral infection. This led to nearly 100% immunoprotective efficacy, enabling neonatal mice delivered by VLP-immunized female adult mice to survive and grow with good health. The present study provided valuable additional knowledge of the specific protective efficacy of the EV71 VLP vaccine in vivo, which also indicated that it is a promising potential candidate for being developed into an EV71 vaccine.

Phantom studies investigating extravascular density imaging for partial volume correction of 3-D PET /sup 18/FDG studies

NASA Astrophysics Data System (ADS)

Wassenaar, R. W.; Beanlands, R. S. B.; deKemp, R. A.

2004-02-01

Limited scanner resolution and cardiac motion contribute to partial volume (PV) averaging of cardiac PET images. An extravascular (EV) density image, created from the subtraction of a blood pool scan from a transmission image, has been used to correct for PV averaging in H/sub 2//sup 15/O studies using 2-D imaging but not with 3-D imaging of other tracers such as /sup 18/FDG. A cardiac phantom emulating the left ventricle was used to characterize the method for use in 3-D PET studies. Measurement of the average myocardial activity showed PV losses of 32% below the true activity (p<0.001). Initial application of the EV density correction still yielded a myocardial activity 13% below the true value (p<0.001). This failure of the EV density image was due to the 1.66 mm thick plastic barrier separating the myocardial and ventricular chambers within the phantom. Upon removal of this artifact by morphological dilation of the blood pool, the corrected myocardial value was within 2% of the true value (p=ns). Spherical ROIs (diameter of 2 to 10 mm), evenly distributed about the myocardium, were also used to calculate the average activity. The EV density image was able to account for PV averaging throughout the range of diameters to within a 5% accuracy, however, a small bias was seen as the size of the ROIs increased. This indicated a slight mismatch between the emission and transmission image resolutions, a result of the difference in data acquisitions (i.e., span and ring difference) and default smoothing. These results show that the use of EV density image to correct for PV averaging is possible with 3-D PET. A method of correcting barrier effects in phantoms has been presented, as well as a process for evaluating resolution mismatch.

Dual baseline search for muon antineutrino disappearance at 0.1eV2<Δm2<100eV2

NASA Astrophysics Data System (ADS)

Cheng, G.; Huelsnitz, W.; Aguilar-Arevalo, A. A.; Alcaraz-Aunion, J. L.; Brice, S. J.; Brown, B. C.; Bugel, L.; Catala-Perez, J.; Church, E. D.; Conrad, J. M.; Dharmapalan, R.; Djurcic, Z.; Dore, U.; Finley, D. A.; Ford, R.; Franke, A. J.; Garcia, F. G.; Garvey, G. T.; Giganti, C.; Gomez-Cadenas, J. J.; Grange, J.; Guzowski, P.; Hanson, A.; Hayato, Y.; Hiraide, K.; Ignarra, C.; Imlay, R.; Johnson, R. A.; Jones, B. J. P.; Jover-Manas, G.; Karagiorgi, G.; Katori, T.; Kobayashi, Y. K.; Kobilarcik, T.; Kubo, H.; Kurimoto, Y.; Louis, W. C.; Loverre, P. F.; Ludovici, L.; Mahn, K. B. M.; Mariani, C.; Marsh, W.; Masuike, S.; Matsuoka, K.; McGary, V. T.; Metcalf, W.; Mills, G. B.; Mirabal, J.; Mitsuka, G.; Miyachi, Y.; Mizugashira, S.; Moore, C. D.; Mousseau, J.; Nakajima, Y.; Nakaya, T.; Napora, R.; Nienaber, P.; Orme, D.; Osmanov, B.; Otani, M.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Ray, H.; Roe, B. P.; Russell, A. D.; Sanchez, F.; Shaevitz, M. H.; Shibata, T.-A.; Sorel, M.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Takei, H.; Tanaka, H.-K.; Tanaka, M.; Tayloe, R.; Taylor, I. J.; Tesarek, R. J.; Uchida, Y.; Van de Water, R. G.; Walding, J. J.; Wascko, M. O.; White, D. H.; White, H. B.; Wickremasinghe, D. A.; Yokoyama, M.; Zeller, G. P.; Zimmerman, E. D.

2012-09-01

The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of ν¯μ at Fermilab’s Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the νμ background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on ν¯μ disappearance that dramatically improves upon prior limits in the Δm2=0.1-100eV2 region.

Surface atomic structure of alloyed Mn 5Ge 3(0 0 0 1) by scanning tunneling microscopy

NASA Astrophysics Data System (ADS)

Kim, Howon; Jung, Goo-Eun; Yoon, Jong Keon; Chung, Kyung Hoon; Kahng, Se-Jong

Surface atomic structure of Mn 5Ge 3(0 0 0 1) is studied by scanning tunneling microscopy. Hexagonal honeycomb ordering is observed at high energy levels, ∣ E - EF∣ ˜ 1.2 eV, on the flat regions of three-dimensional Mn 5Ge 3 islands. At low energy levels, ∣ E - EF∣ ˜ 0.5 eV, however, atomic images exhibit dot-array and ring-array structures, which show complete and partial contrast inversion, compared to the honeycomb ordering. Experimental observations are discussed on the basis of possible atomic models.

Coxsackievirus A6 and enterovirus 71 causing hand, foot and mouth disease in Cuba, 2011-2013.

PubMed

Fonseca, Magilé C; Sarmiento, Luis; Resik, Sonia; Martínez, Yenisleidys; Hung, Lai Heng; Morier, Luis; Piñón, Alexander; Valdéz, Odalys; Kourí, Vivian; González, Guelsys

2014-09-01

Hand, foot and mouth disease (HFMD) is usually caused by coxsackievirus A16 or enterovirus 71 (EV71). Between 2011 and 2013, HFMD cases were reported from different Cuban provinces. A total of 42 clinical specimens were obtained from 23 patients. Detection, identification and phylogenetic analysis of enterovirus-associated HFMD were carried out by virus isolation, specific enterovirus PCR and partial VP1 sequences. HEV was detected in 11 HFMD cases. Emerging genetic variants of coxsackievirus A6 and EV71 were identified as the causative agents of the Cuban HFMD cases.

Flow Cytometry of Extracellular Vesicles: Potential, Pitfalls, and Prospects.

PubMed

Nolan, John P

2015-07-01

Evidence suggests that extracellular vesicles (EVs) can play roles in physiology and pathology, providing impetus to explore their use as diagnostic and therapeutic targets. However, EVs are also small, heterogeneous, and difficult to measure, and so this potential has not yet been realized. The development of improved approaches to EV detection and characterization will be critical to further understanding their roles in physiology and disease. Flow cytometry has been a popular tool for measuring cell-derived EVs, but has often been used in an uncritical manner in which fundamental principles and limitations of the instrument are ignored. Recent efforts to standardize procedures and document the effects of different methodologies have helped to address this shortcoming, but much work remains. In this paper, I address some of the instrument, reagent, and analysis considerations relevant to measurement of individual EVs in flow, with the aim of clarifying a path to quantitative and standardized measurement of these interesting and potentially important biological nanoparticles. Copyright © 2015 John Wiley & Sons, Inc.

Mesenchymal stromal cell derived extracellular vesicles rescue radiation damage to murine marrow hematopoietic cells

PubMed Central

Wen, Sicheng; Dooner, Mark; Cheng, Yan; Papa, Elaine; Del Tatto, Michael; Pereira, Mandy; Deng, Yanhui; Goldberg, Laura; Aliotta, Jason; Chatterjee, Devasis; Stewart, Connor; Carpanetto, Andrea; Collino, Federica; Bruno, Stefania; Camussi, Giovanni; Quesenberry, Peter

2016-01-01

Mesenchymal stromal cells (MSC) have been shown to reverse radiation damage to marrow stem cells. We have evaluated the capacity of MSC-derived extracellular vesicles (MSC-EVs) to mitigate radiation injury to marrow stem cells at 4 hours to 7 days after irradiation. Significant restoration of marrow stem cell engraftment at 4, 24 and 168 hours post-irradiation by exposure to MSC-EVs was observed at 3 weeks to 9 months after transplant and further confirmed by secondary engraftment. Intravenous injection of MSC-EVs to 500cGy exposed mice led to partial recovery of peripheral blood counts and restoration of the engraftment of marrow. The murine hematopoietic cell line, FDC-P1 exposed to 500 cGy, showed reversal of growth inhibition, DNA damage and apoptosis on exposure to murine or human MSC-EVs. Both murine and human MSC-EVs reverse radiation damage to murine marrow cells and stimulate normal murine marrow stem cell/progenitors to proliferate. A preparation with both exosomes and microvesicles was found to be superior to either microvesicles or exosomes alone. Biologic activity was seen in freshly isolated vesicles and in vesicles stored for up to 6 months in 10% DMSO at −80°C. These studies indicate that MSC-EVs can reverse radiation damage to bone marrow stem cells. PMID:27150009

Adsorption and dissociation of H2O on the (001) surface of uranium mononitride: energetics and mechanism from first-principles investigation.

PubMed

Bo, Tao; Lan, Jian-Hui; Zhang, Yu-Juan; Zhao, Yao-Lin; He, Chao-Hui; Chai, Zhi-Fang; Shi, Wei-Qun

2016-05-21

The interfacial interaction of uranium mononitride (UN) with water from the environment unavoidably leads to corrosion of nuclear fuels, which affects a lot of processes in the nuclear fuel cycle. In this work, the microscopic adsorption behaviors of water on the UN(001) surface as well as water dissociation and accompanying H2 formation mechanisms have been investigated on the basis of DFT+U calculations and ab initio atomistic thermodynamics. For adsorption of one H2O monomer, the predicted adsorption energies are -0.88, -2.07, and -2.07 eV for the most stable molecular, partially dissociative, and completely dissociative adsorption, respectively. According to our calculations, a water molecule dissociates into OH and H species via three pathways with small energy barriers of 0.78, 0.72, and 0.85 eV, respectively. With the aid of the neighboring H atom, H2 formation through the reaction of H* + OH* can easily occur via two pathways with energy barriers of 0.61 and 0.36 eV, respectively. The molecular adsorption of water shows a slight coverage dependence on the surface while this dependence becomes obvious for partially dissociative adsorption as the water coverage increases from 1/4 to 1 ML. In addition, based on the "ab initio atomistic thermodynamic" simulations, increasing H2O partial pressure will enhance the stability of the adsorbed system and water coverage, while increasing temperature will decrease the H2O coverage. We found that the UN(001) surface reacts easily with H2O at room temperature, leading to dissolution and corrosion of the UN fuel materials.

Emerging Roles for Extracellular Vesicles in Tissue Engineering and Regenerative Medicine

PubMed Central

Lamichhane, Tek N.; Sokic, Sonja; Schardt, John S.; Raiker, Rahul S.; Lin, Jennifer W.

2015-01-01

Extracellular vesicles (EVs)—comprising a heterogeneous population of cell-derived lipid vesicles including exosomes, microvesicles, and others—have recently emerged as both mediators of intercellular information transfer in numerous biological systems and vehicles for drug delivery. In both roles, EVs have immense potential to impact tissue engineering and regenerative medicine applications. For example, the therapeutic effects of several progenitor and stem cell-based therapies have been attributed primarily to EVs secreted by these cells, and EVs have been recently reported to play direct roles in injury-induced tissue regeneration processes in multiple physiological systems. In addition, EVs have been utilized for targeted drug delivery in regenerative applications and possess unique potential to be harnessed as patient-derived drug delivery vehicles for personalized medicine. This review discusses EVs in the context of tissue repair and regeneration, including their utilization as drug carriers and their crucial role in cell-based therapies. Furthermore, the article highlights the growing need for bioengineers to understand, consider, and ultimately design and specifically control the activity of EVs to maximize the efficacy of tissue engineering and regenerative therapies. PMID:24957510

Single dose of an adenovirus vectored mouse interferon-α protects mice from lethal EV71 challenge.

PubMed

Sun, Jialei; Ennis, Jane; Turner, Jeffrey D; Chu, Justin Jang Hann

2016-10-01

Enterovirus 71 (EV71) causes hand-foot-and-mouth diseases as well as neurological complications in young children. Interferon (IFN) can inhibit the replication of many viruses with low cytotoxic effects. Previously, an adenovirus vectored mouse interferon-α (DEF201), subtype 5, was generated by Wu et al, 2007. In this study, the antiviral effects of DEF201 against EV71 were evaluated in a murine model. 6-day-old BALB/c mice were administered a single dose of DEF201 before or after infection with lethal dose of EV71. The survival rate, clinical symptoms, tissue viral loads and histology pathogenesis were evaluated. IFN gene expression following a single dose of DEF201 maintained high concentrations of 100-9000 pg/mL for more than 7 days in mice serum. Pre-infection administration of a single dose of 10 6  PFU of DEF201 offered full protection of the mice against EV71 infection compared with the empty Ad5 vector control. In addition, virus load in DEF201-treated mice muscle tissue was significantly decreased as compared with empty vector control. Histopathology analysis revealed that DEF201 significantly prevented the development of severe tissue damage with reduction of viral antigen in the murine muscle tissue. Post-infection treatment at 6 h offered full protection and partial protection at 12 h, indicating that DEF201 could be used as an anti-EV71 therapeutic agent in early stage of EV71 infection. In addition, our study showed that DEF201 enhanced the neutralization ability of serum in EV71-vaccinated mice, implying that DEF201 could promote the production of specific anti-EV71 antibodies. In conclusion, single dose of DEF201 is highly efficacious as a prophylactic agent against EV71 infection in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

Ab-initio Computation of the Electronic, transport, and Bulk Properties of Calcium Oxide.

NASA Astrophysics Data System (ADS)

Mbolle, Augustine; Banjara, Dipendra; Malozovsky, Yuriy; Franklin, Lashounda; Bagayoko, Diola

We report results from ab-initio, self-consistent, local Density approximation (LDA) calculations of electronic and related properties of calcium oxide (CaO) in the rock salt structure. We employed the Ceperley and Alder LDA potential and the linear combination of atomic orbitals (LCAO) formalism. Our calculations are non-relativistic. We implemented the LCAO formalism following the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF). The BZW-EF method involves a methodical search for the optimal basis set that yields the absolute minima of the occupied energies, as required by density functional theory (DFT). Our calculated, indirect band gap of 6.91eV, from towards the L point, is in excellent agreement with experimental value of 6.93-7.7eV, at room temperature (RT). We have also calculated the total (DOS) and partial (pDOS) densities of states as well as the bulk modulus. Our calculated bulk modulus is in excellent agreement with experiment. Work funded in part by the US Department of Energy (DOE), National Nuclear Security Administration (NNSA) (Award No.DE-NA0002630), the National Science Foundation (NSF) (Award No, 1503226), LaSPACE, and LONI-SUBR.

Pseudopotentials for quantum Monte Carlo studies of transition metal oxides

DOE PAGES

Krogel, Jaron T.; Santana Palacio, Juan A.; Reboredo, Fernando A.

2016-02-22

Quantum Monte Carlo (QMC) calculations of transition metal oxides are partially limited by the availability of high-quality pseudopotentials that are both accurate in QMC and compatible with major plane-wave electronic structure codes. We have generated a set of neon-core pseudopotentials with small cutoff radii for the early transition metal elements Sc to Zn within the local density approximation of density functional theory. The pseudopotentials have been directly tested for accuracy within QMC by calculating the first through fourth ionization potentials of the isolated transition metal (M) atoms and the binding curve of each M-O dimer. We find the ionization potentialsmore » to be accurate to 0.16(1) eV, on average, relative to experiment. The equilibrium bond lengths of the dimers are within 0.5(1)% of experimental values, on average, and the binding energies are also typically accurate to 0.18(3) eV. The level of accuracy we find for atoms and dimers is comparable to what has recently been observed for bulk metals and oxides using the same pseudopotentials. Our QMC pseudopotential results compare well with the findings of previous QMC studies and benchmark quantum chemical calculations.« less

Accurate quantum wave packet calculations for the F + HCl → Cl + HF reaction on the ground 1(2)A' potential energy surface.

PubMed

Bulut, Niyazi; Kłos, Jacek; Alexander, Millard H

2012-03-14

We present converged exact quantum wave packet calculations of reaction probabilities, integral cross sections, and thermal rate coefficients for the title reaction. Calculations have been carried out on the ground 1(2)A' global adiabatic potential energy surface of Deskevich et al. [J. Chem. Phys. 124, 224303 (2006)]. Converged wave packet reaction probabilities at selected values of the total angular momentum up to a partial wave of J = 140 with the HCl reagent initially selected in the v = 0, j = 0-16 rovibrational states have been obtained for the collision energy range from threshold up to 0.8 eV. The present calculations confirm an important enhancement of reactivity with rotational excitation of the HCl molecule. First, accurate integral cross sections and rate constants have been calculated and compared with the available experimental data.

STRUCTURE AND PHYSICAL PROPERTIES OF SOLID AND LIQUID VANADIUM PENTOXIDE.

DTIC Science & Technology

The electrical resistivity of near-stoichiometric crystalline V2O5 was measured as a function of crystal orientation and oxygen partial pressure from...25C to 300C. Conductivity is insensitive to ambient atmosphere. The activation energy for conduction is 0.20 ev. Molten V2O5 , however, is...sensitive to oxygen partial pressure. Its conductivity is proportional to P-O2 to the -1/6th power. Anomalously high electrical resistivity was observed for glassy V2O5 films. (Author)

[Comparative life cycle environmental assessment between electric taxi and gasoline taxi in Beijing].

PubMed

Shi, Xiao-Qing; Sun, Zhao-Xin; Li, Xiao-Nuo; Li, Jin-Xiang; Yang, Jian-Xin

2015-03-01

Tailpipe emission of internal combustion engine vehicle (ICEV) is one of the main sources leading to atmospheric environmental problems such as haze. Substituting electric vehicles for conventional gasoline vehicles is an important solution for reducing urban air pollution. In 2011, as a pilot city of electric vehicle, Beijing launched a promotion plan of electric vehicle. In order to compare the environmental impacts between Midi electric vehicle (Midi EV) and Hyundai gasoline taxi (ICEV), this study created an inventory with local data and well-reasoned assumptions, and contributed a life cycle assessment (LCA) model with GaBi4.4 software and comparative life cycle environmental assessment by Life cycle impact analysis models of CML2001(Problem oriented) and EI99 (Damage oriented), which included the environmental impacts of full life cycle, manufacture phase, use phase and end of life. The sensitivity analysis of lifetime mileage and power structure was also provided. The results indicated that the full life cycle environmental impact of Midi EV was smaller than Hyundai ICEV, which was mainly due to the lower fossil fuel consumption. On the contrary, Midi EV exhibited the potential of increasing the environmental impacts of ecosystem quality influence and Human health influence. By CML2001 model, the results indicated that Midi EV might decrease the impact of Abiotic Depletion Potential, Global Warming Potential, Ozone Layer Depletion Potential and so on. However, in the production phase, the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Ozone Layer Depletion Potential, Marine Aquatic Ecotoxicity Potential, Terrestric Ecotoxicity Potential, Human Toxicity Potential of Midi EV were increased relative to Hyundai ICEV because of emissions impacts from its power system especially the battery production. Besides, in the use phase, electricity production was the main process leading to the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Marine Aquatic Ecotoxicity Potential, Freshwater Aquatic Ecotoxicity Potential, Human Toxicity Potential. While for Hyundai ICEV, gasoline production and tailpipe emission were the primary sources of environmental impact in the use phase. Tailpipe emission was a significant cause for increase in Eutrophication Potential and Global Warming Potential, and so forth. On the basis of inventory data analysis and 2010 Beijing electricity mix, the comparative results of haze-induced pollutants emissions showed that the full life cycle emissions of PM2.5, NO(x), SO(x), VOCs of Midi EV were higher than those of Hyundai ICEV, but the emission of NH3 was lower than that of Hyundai ICEV. Different emissions in use phase were the chief reason leading to this trend. In addition, by sensitivity analysis the results indicated that with the increase of lifetime mileage and proportion of cleaning energy, the rate of GHG( Green House Gas) emission reduction per kilometer of Midi EV became higher with respect to Hyundai ICEV. Haze-induced pollutants emission from EV could be significantly reduced using cleaner power energy. According to the assessment results, some management strategies aiming at electric car promotion were proposed.

Synthesis and electronic properties of Fe 2TiO 5 epitaxial thin films

DOE PAGES

Osada, Motoki; Nishio, Kazunori; Hwang, Harold Y.; ...

2018-05-02

Here, we investigate the growth phase diagram of pseudobrookite Fe 2TiO 5 epitaxial thin films on LaAlO 3 (001) substrates using pulsed laser deposition. Control of the oxygen partial pressure and temperature during deposition enabled selective stabilization of (100)- and (230)-oriented films. In this regime, we find an optical gap of 2.1 eV and room temperature resistivity in the range of 20–80 Ω cm, which are significantly lower than α-Fe 2O 3, making Fe 2TiO 5 potentially an ideal inexpensive visible-light harvesting semiconductor. These results provide a basis to incorporate Fe 2TiO 5 in oxide heterostructures for photocatalytic and photoelectrochemicalmore » applications.« less

Synthesis and electronic properties of Fe2TiO5 epitaxial thin films

NASA Astrophysics Data System (ADS)

Osada, Motoki; Nishio, Kazunori; Hwang, Harold Y.; Hikita, Yasuyuki

2018-05-01

We investigate the growth phase diagram of pseudobrookite Fe2TiO5 epitaxial thin films on LaAlO3 (001) substrates using pulsed laser deposition. Control of the oxygen partial pressure and temperature during deposition enabled selective stabilization of (100)- and (230)-oriented films. In this regime, we find an optical gap of 2.1 eV and room temperature resistivity in the range of 20-80 Ω cm, which are significantly lower than α-Fe2O3, making Fe2TiO5 potentially an ideal inexpensive visible-light harvesting semiconductor. These results provide a basis to incorporate Fe2TiO5 in oxide heterostructures for photocatalytic and photoelectrochemical applications.

Procoagulant activity of extracellular vesicles as a potential biomarker for risk of thrombosis and DIC in patients with acute leukaemia.

PubMed

Gheldof, Damien; Haguet, Hélène; Dogné, Jean-Michel; Bouvy, Céline; Graux, Carlos; George, Fabienne; Sonet, Anne; Chatelain, Christian; Chatelain, Bernard; Mullier, François

2017-02-01

Haemostatic complication is common for patients with hematologic malignancies. Recent studies suggest that the procoagulant activity (PCA) of extracellular vesicles (EV) may play a major role in venous thromboembolism and disseminated intravascular coagulation (DIC) in acute leukaemia. To study the impact of EVs from leukaemic patients on thrombin generation and to assess EV-PCA as a potential biomarker for thrombotic complications in patients with acute leukaemia. Blood samples from a cohort of patients with newly diagnosed acute leukaemia were obtained before treatment (D-0), 3 and 7 days after treatment (D-3 and D-7). Extracellular vesicles were isolated and concentrated by ultracentrifugation. EV-PCA was assessed by thrombin generation assay, and EV-associated tissue factor activity was measured using a commercial bio-immunoassay (Zymuphen MP-TF®). Of the 53 patients, 6 had increased EV-PCA at D-0 and 4 had a thrombotic event. Patients without thrombotic events (n = 47) had no elevated EV-PCA. One patient had increased EVs with procoagulant activity at D-3 and developed a DIC at D-5. This patient had no increased EVs-related tissue factor activity from D-0 to D-7 (<2 pg/ml). Eight patients had increased EVs with tissue factor activity (>2 pg/ml), of these, four had a thrombosis and two had haemorrhages. Procoagulant activity of extracellular vesicles could have a predictive value in excluding the risk of thrombotic events. Our findings also suggest a possible association between thrombotic events and EV-PCA.

Exosome and microvesicle mediated phene transfer in mammalian cells.

PubMed

Christianson, Helena C; Svensson, Katrin J; Belting, Mattias

2014-10-01

Extracellular vesicles (EVs), e.g. exosomes and microvesicles, emerge as new signaling organelles in the exchange of information between cells at the paracrine and systemic level. It is clear that these virus like particles carry complex biological information that can elicit a pleiotropic response in recipient cells with potential relevance in physiology as well as in cancer and other pathological conditions. Numerous studies convincingly show that the molecular composition of EVs closely reflects their cell or tissue of origin. Thus, the signaling status of donor cells, more specifically their endosomal compartments, may largely determine the biological output in recipient cells, a process that we then may conceptualize as vesicle mediated phene transfer. Whereas more conventional modes of cell-cell communication mostly depend on extracellular ligand concentration and cell-surface receptor availability, the magnitude of the EV signaling response relies on the capture and uptake by target cells, allowing release of the EV content. Numerous reports point at the intriguing possibility that, among thousands of mRNAs, miRNAs, and proteins, single EV constituents effectuate the biological response, e.g. stimulation of angiogenesis and cancer cell metastasis, in recipient cells; however, we find it conceivable that strategies targeted at general mechanisms of EV function should provide more rational avenues for therapeutic intervention directed at the EV system. Such strategies include manipulation of EV formation in the endolysosomal system, EV stability in the extracellular milieu, and EV entry into target cells. Here, we provide important insights into potential mechanisms of EV transport in mammalian cells and how these may be targeted. Copyright © 2014 Elsevier Ltd. All rights reserved.

Efficient polymer light-emitting diode with air-stable aluminum cathode

NASA Astrophysics Data System (ADS)

Abbaszadeh, D.; Wetzelaer, G. A. H.; Doumon, N. Y.; Blom, P. W. M.

2016-03-01

The fast degradation of polymer light-emitting diodes (PLEDs) in ambient conditions is primarily due to the oxidation of highly reactive metals, such as barium or calcium, which are used as cathode materials. Here, we report the fabrication of PLEDs using an air-stable partially oxidized aluminum (AlOx) cathode. Usually, the high work function of aluminum (4.2 eV) imposes a high barrier for injecting electrons into the lowest unoccupied molecular orbital (LUMO) of the emissive polymer (2.9 eV below the vacuum level). By partially oxidizing aluminum, its work function is decreased, but not sufficiently low for efficient electron injection. Efficient injection is obtained by inserting an electron transport layer of poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (F8BT), which has its LUMO at 3.3 eV below vacuum, between the AlOx cathode and the emissive polymer. The intermediate F8BT layer not only serves as a hole-blocking layer but also provides an energetic staircase for electron injection from AlOx into the emissive layer. PLEDs with an AlOx cathode and F8BT interlayer exhibit a doubling of the efficiency as compared to conventional Ba/Al PLEDs, and still operate even after being kept in ambient atmosphere for one month without encapsulation.

Magnetocrystalline anisotropy of ɛ-Fe2O3

NASA Astrophysics Data System (ADS)

Ahamed, Imran; Pathak, Rohit; Skomski, Ralph; Kashyap, Arti

2018-05-01

The epsilon Fe2O3 phase of iron oxide has been studied to understand the spin structure and the magnetocrystalline anisotropy in the bulk and in thin films of ɛ-Fe2O3 and Co-doped ɛ-Fe2O3. The preferential magnetization direction in the nanoparticles of ɛ-Fe2O3 is along the a-axis [M. Gich et al., Chem. Mater. 18, 3889 (2006)]. Compared to the bulk band gap of 1.9 eV, the thin-film band gap is reduced to 1.3 eV in the Co-free films and to 0.7 eV in the film with partial Co substitution. The easy magnetization direction of the bulk and Co-free ɛ-Fe2O3 is along the c-axis, but it switches to the a-axis on Co substitution. All three systems exhibit in-plane anisotropies associated with the orthorhombic crystal structure of the oxide.

Market Model of Financing Higher Education in Sub-Saharan Africa: Examples from Kenya.

ERIC Educational Resources Information Center

Oketch, Moses O.

2003-01-01

Examines some of the rationales for financial diversification and partial privatization of state universities in Kenya and the different manifestations of market-driven approaches to university education. Explores whether the market model can address increased demand while maintaining educational quality. (EV)

Analysis of Electric Vehicle Charging Impact on the Electric Power Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Zeming; Tian, Hao; Beshir, Mohammed J.

2016-09-24

In order to evaluate the impact of electric vehicles (EVs) on the distribution grid and assess their potential benefits to the future smart grid, it is crucial to study the EV charging patterns and the usage charging station. Though EVs are not yet widely adopted nationwide, a valuable methodology to conduct such studies is the statistical analysis of real-world charging data. This paper presents actual EV charging behavior of 64 EVs (5 brands, 8 models) from EV users and charging stations at Los Angeles Department of Water and Power for more than one year. Twenty-four-hour EV charging load curves havemore » been generated and studied for various load periods: daily, monthly, seasonally and yearly. Finally, the effect and impact of EV load on the California distribution network are evaluated at different EV penetration rates.« less

Antiviral effects of two Ganoderma lucidum triterpenoids against enterovirus 71 infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wenjing; Tao, Junyan; Yang, Xiaoping

Highlights: • Triterpenoids GLTA and GLTB display anti-EV71 activities without cytotoxicity. • The compounds prevent EV71 infection by blocking adsorption of the virus to the cells. • GLTA and GLTB bind to EV71 capsid at the hydrophobic pocket to block EV71 uncoating. • The two compounds significantly inhibit the replication of EV71 viral RNA. • GLTA and GLTB may be used as potential therapeutic agents to treat EV71 infection. - Abstract: Enterovirus 71 (EV71) is a major causative agent for hand, foot and mouth disease (HFMD), and fatal neurological and systemic complications in children. However, there is currently no clinicalmore » approved antiviral drug available for the prevention and treatment of the viral infection. Here, we evaluated the antiviral activities of two Ganoderma lucidum triterpenoids (GLTs), Lanosta-7,9(11),24-trien-3-one,15;26-dihydroxy (GLTA) and Ganoderic acid Y (GLTB), against EV71 infection. The results showed that the two natural compounds display significant anti-EV71 activities without cytotoxicity in human rhabdomyosarcoma (RD) cells as evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay. The mechanisms by which the two compounds affect EV71 infection were further elucidated by three action modes using Ribavirin, a common antiviral drug, as a positive control. The results suggested that GLTA and GLTB prevent EV71 infection through interacting with the viral particle to block the adsorption of virus to the cells. In addition, the interactions between EV71 virion and the compounds were predicated by computer molecular docking, which illustrated that GLTA and GLTB may bind to the viral capsid protein at a hydrophobic pocket (F site), and thus may block uncoating of EV71. Moreover, we demonstrated that GLTA and GLTB significantly inhibit the replication of the viral RNA (vRNA) of EV71 replication through blocking EV71 uncoating. Thus, GLTA and GLTB may represent two potential therapeutic agents to control and treat EV71 infection.« less

Distributed Solar Photovoltaics for Electric Vehicle Charging: Regulatory and Policy Considerations (Brochure)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2014-09-01

Increasing demand for electric vehicle (EV) charging provides an opportunity for market expansion of distributed solar technology. A major barrier to the current deployment of solar technology for EV charging is a lack of clear information for policy makers, utilities and potential adopters. This paper introduces the pros and cons of EV charging during the day versus at night, summarizes the benefits and grid implications of combining solar and EV charging technologies, and offers some regulatory and policy options available to policy makers and regulators wanting to incentivize solar EV charging.

African Non-Human Primates Host Diverse Enteroviruses.

PubMed

Mombo, Illich Manfred; Lukashev, Alexander N; Bleicker, Tobias; Brünink, Sebastian; Berthet, Nicolas; Maganga, Gael D; Durand, Patrick; Arnathau, Céline; Boundenga, Larson; Ngoubangoye, Barthélémy; Boué, Vanina; Liégeois, Florian; Ollomo, Benjamin; Prugnolle, Franck; Drexler, Jan Felix; Drosten, Christian; Renaud, François; Rougeron, Virginie; Leroy, Eric

2017-01-01

Enteroviruses (EVs) belong to the family Picornaviridae and are responsible for mild to severe diseases in mammals including humans and non-human primates (NHP). Simian EVs were first discovered in the 1950s in the Old World Monkeys and recently in wild chimpanzee, gorilla and mandrill in Cameroon. In the present study, we screened by PCR EVs in 600 fecal samples of wild apes and monkeys that were collected at four sites in Gabon. A total of 32 samples were positive for EVs (25 from mandrills, 7 from chimpanzees, none from gorillas). The phylogenetic analysis of VP1 and VP2 genes showed that EVs identified in chimpanzees were members of two human EV species, EV-A and EV-B, and those identified in mandrills were members of the human species EV-B and the simian species EV-J. The identification of two novel enterovirus types, EV-B112 in a chimpanzee and EV-B113 in a mandrill, suggests these NHPs could be potential sources of new EV types. The identification of EV-B107 and EV90 that were previously found in humans indicates cross-species transfers. Also the identification of chimpanzee-derived EV110 in a mandrill demonstrated a wide host range of this EV. Further research of EVs in NHPs would help understanding emergence of new types or variants, and evaluating the real risk of cross-species transmission for humans as well for NHPs populations.

Genetic characterization of enterovirus strains identified in Hand, Foot and Mouth Disease (HFMD): Emergence of B1c, C1 subgenotypes, E2 sublineage of CVA16, EV71 and CVA6 strains in India.

PubMed

Ganorkar, Nital N; Patil, Pooja R; Tikute, Sanjay S; Gopalkrishna, Varanasi

2017-10-01

Hand, Foot and Mouth disease (HFMD) is a common childhood disease and caused due to Enterovirus-A (EV-A), EV-B and EV-C species worldwide. Cases of HFMD were reported from, Ahmedabad (Gujarat, 2012) and Pune (Maharashtra, 2013-2014) in India. The present study highlights the identification of EV strains (CVA16, CVA6, CVA4 and Echo12), characterization of subgenotypes of CVA16, CVA6 strains during 2012-14 and CVA16, CVA6, EV71 strains reported from the earlier study (2009-10) in HFMD cases from India. A total 158 clinical specimens collected from 64 HFMD cases (2012-2014) were included in the study. EV detection was carried out by 5'NCR based RT-PCR, molecular typing and subgenotyping was by VP1/2A junction or VP1, full VP1 gene amplification respectively followed by phylogenetic analysis. The present study reports 63.92% (101/158) EV positivity by RT-PCR. Ninety four of the 101 (93.06%) EV positive strains were amplified by VP1/2A junction or VP1 regions. Sequence analysis revealed the presence of CVA16 (61.7%), CVA6 (34.04%), CVA4 and Echo12 (4.3%). A total of 114 EV positive strains were genotyped using full and partial VP1 region. All CVA16 Indian strains (n=70) clustered with rarely reported B1c subgenotype, CVA6 (n=43) and EV71 (n=1) strains clustered with sub-lineage E2 and C1 subgenotypes respectively. In summary, the study reports genetic characterization of CVA16, CVA6, CVA4 and Echo12 strains in HFMD cases from India. Circulation of B1c subgenotype of CVA16, E2 sub-lineage of CVA6 and C1 subgenotype of EV 71 strains in HFMD cases were reported for the first time from India. This study helps to understand the genotype distribution, genetic diversity of EV strains associated with HFMD from Eastern, Western and Southern regions in India. Copyright © 2017 Elsevier B.V. All rights reserved.

Tunneling effect on double potential barriers GaAs and PbS

NASA Astrophysics Data System (ADS)

Prastowo, S. H. B.; Supriadi, B.; Ridlo, Z. R.; Prihandono, T.

2018-04-01

A simple model of transport phenomenon tunnelling effect through double barrier structure was developed. In this research we concentrate on the variation of electron energy which entering double potential barriers to transmission coefficient. The barriers using semiconductor materials GaAs (Galium Arsenide) with band-gap energy 1.424 eV, distance of lattice 0.565 nm, and PbS (Lead Sulphide) with band gap energy 0.41 eV distance of lattice is 18 nm. The Analysisof tunnelling effect on double potentials GaAs and PbS using Schrodinger’s equation, continuity, and matrix propagation to get transmission coefficient. The maximum energy of electron that we use is 1.0 eV, and observable from 0.0025 eV- 1.0 eV. The shows the highest transmission coefficient is0.9982 from electron energy 0.5123eV means electron can pass the barriers with probability 99.82%. Semiconductor from materials GaAs and PbS is one of selected material to design semiconductor device because of transmission coefficient directly proportional to bias the voltage of semiconductor device. Application of the theoretical analysis of resonant tunnelling effect on double barriers was used to design and develop new structure and combination of materials for semiconductor device (diode, transistor, and integrated circuit).

Layer Dependence and Light Tuning Surface Potential of 2D MoS2 on Various Substrates.

PubMed

Li, Feng; Qi, Junjie; Xu, Minxuan; Xiao, Jiankun; Xu, Yuliang; Zhang, Xiankun; Liu, Shuo; Zhang, Yue

2017-04-01

Here surface potential of chemical vapor deposition (CVD) grown 2D MoS 2 with various layers is reported, and the effect of adherent substrate and light illumination on surface potential of monolayer MoS 2 are investigated. The surface potential of MoS 2 on Si/SiO 2 substrate decreases from 4.93 to 4.84 eV with the increase in the number of layer from 1 to 4 or more. Especially, the surface potentials of monolayer MoS 2 are strongly dependent on its adherent substrate, which are determined to be 4.55, 4.88, 4.93, 5.10, and 5.50 eV on Ag, graphene, Si/SiO 2 , Au, and Pt substrates, respectively. Light irradiation is introduced to tuning the surface potential of monolayer MoS 2 , with the increase in light intensity, the surface potential of MoS 2 on Si/SiO 2 substrate decreases from 4.93 to 4.74 eV, while increases from 5.50 to 5.56 eV on Pt substrate. The I-V curves on vertical of monolayer MoS 2 /Pt heterojunction show the decrease in current with the increase of light intensity, and Schottky barrier height at MoS 2 /Pt junctions increases from 0.302 to 0.342 eV. The changed surface potential can be explained by trapped charges on surface, photoinduced carriers, charge transfer, and local electric field. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tailored emails prompt electric vehicle owners to engage with tariff switching information

NASA Astrophysics Data System (ADS)

Nicolson, Moira; Huebner, Gesche M.; Shipworth, David; Elam, Simon

2017-06-01

The carbon intensity of the electricity used to charge an electric vehicle (EV) is dependent on when in the day charging occurs. However, persuading EV owners to adopt incentives to charge during off-peak hours is challenging. Here we show that governments could exploit the 'window of opportunity' created when people purchase their first EV to promote time-of-use tariffs. Email recipients (n = 7,038 EV owners) were more likely to click-through to an information webpage when the email emphasized specific reductions in home-charging costs versus general bill savings. However, the 'window of opportunity' for maximizing potential adoption is short; email open rates declined from over 70% immediately after purchase to 40% for recipients owning their EV for over three months. These results demonstrate the potential of prompts to change behaviours for which opt-out enrolment (where enrolment is automatic unless people explicitly opt out) would be unethical or less effective.

Laser Desorption 7.87 eV Postionization Mass Spectrometry of Antibiotics in Staphylococcus epidermidis Bacterial Biofilms

PubMed Central

Gasper, Gerald L.; Carlson, Ross; Akhmetov, Artem; Moore, Jerry F.; Hanley, Luke

2010-01-01

This paper describes the development of laser desorption 7.87 eV vacuum ultraviolet postionization mass spectrometry (LDPI-MS) to detect antibiotics within intact bacterial colony biofilms. As >99% of the molecules ejected by laser desorption are neutrals, vacuum ultraviolet (VUV) photoionization of these neutrals can provide significantly increased signal compared to detection of directly emitted ions. Postionization with VUV radiation from the molecular fluorine laser single photon ionizes laser desorbed neutrals with ionization potentials below the 7.87 eV photon energy. Antibiotics with structures indicative of sub-7.87 eV ionization potentials were examined for their ability to be detected by 7.87 eV LDPI-MS. Tetracycline, sulfadiazine, and novobiocin were successfully detected neat as dried films physisorbed on porous silicon oxide substrates. Tetracycline and sulfadiazine were then detected within intact Staphylococcus epidermidis colony biofilms, the former with LOD in the micromolar concentration range. PMID:18704905

Characterization and Pharmacological Properties of a Novel Multifunctional Kunitz Inhibitor from Erythrina velutina Seeds

PubMed Central

Machado, Richele J. A.; Monteiro, Norberto K. V.; Migliolo, Ludovico; Silva, Osmar N.; Pinto, Michele F. S.; Oliveira, Adeliana S.; Franco, Octávio L.; Kiyota, Sumika; Bemquerer, Marcelo P.; Uchoa, Adriana F.; Morais, Ana H. A.; Santos, Elizeu A.

2013-01-01

Inhibitors of peptidases isolated from leguminous seeds have been studied for their pharmacological properties. The present study focused on purification, biochemical characterization and anti-inflammatory and anticoagulant evaluation of a novel Kunitz trypsin inhibitor from Erythrina velutina seeds (EvTI). Trypsin inhibitors were purified by ammonium sulfate (30–60%), fractionation followed by Trypsin-Sepharose affinity chromatography and reversed-phase high performance liquid chromatography. The purified inhibitor showed molecular mass of 19,210.48 Da. Furthermore, a second isoform with 19,228.16 Da was also observed. The inhibitor that showed highest trypsin specificity and enhanced recovery yield was named EvTI (P2) and was selected for further analysis. The EvTI peptide fragments, generated by trypsin and pepsin digestion, were further analyzed by MALDI-ToF-ToF mass spectrometry, allowing a partial primary structure elucidation. EvTI exhibited inhibitory activity against trypsin with IC50 of 2.2×10−8 mol.L−1 and constant inhibition (Ki) of 1.0×10−8 mol.L−1, by a non-competitive mechanism. In addition to inhibit the activity of trypsin, EvTI also inhibited factor Xa and neutrophil elastase, but do not inhibit thrombin, chymotrypsin or peptidase 3. EvTI was investigated for its anti-inflammatory and anti-coagulant properties. Firstly, EvTI showed no cytotoxic effect on human peripheral blood cells. Nevertheless, the inhibitor was able to prolong the clotting time in a dose-dependent manner by using in vitro and in vivo models. Due to anti-inflammatory and anticoagulant EvTI properties, two sepsis models were here challenged. EvTI inhibited leukocyte migration and specifically acted by inhibiting TNF-α release and stimulating IFN-α and IL-12 synthesis. The data presented clearly contribute to a better understanding of the use of Kunitz inhibitors in sepsis as a bioactive agent capable of interfering in blood coagulation and inflammation. PMID:23737945

The lowest ionization potentials of Al2

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Barnes, Leslie A.; Taylor, Peter R.

1988-01-01

Potential curves for the lowest two electronic states (X 2 sigma g + and A 2 pi u) of Al2(+) were computed using complete active space SCF/multireference CI wave functions and large Gaussian basis sets. The lowest observable vertical ionization potential (to Al2(+) X 2 sigma g +) of the Al2 X 3 pi u ground state is calculated to occur around 6.1 eV, in excellent agreement with the experimental range of 6.0 to 6.42 eV obtained in recent cluster ionization studies by Cox and co-workers. The second vertical ionization potential (to Al2(+) A 2 pi u) occurs near 6.4 eV, also within the experimental range. The adiabatic IP of 5.90 eV is in good agreement with the value of 5.8 to 6.1 eV deduced by Hanley and co-workers from the difference in thresholds between collision induced dissociation processes of Al3(+). The computed IP values are somewhat larger than those deduced from branching ratios in cluster fragmentation experiments by Jarrold and co-workers. The observation of an ionization threshold below 6.42 eV is shown to be incompatible with an Al2 ground electronic state assignment of 3 sigma g -, but the separation between the two lowest states of Al2 is so small that it is likely that both are populated in the experiments, so that this does not provide unambiguous support for the recent theoretical assignment of the ground state as 3 pi u.

First Enterovirus D68 (EV-D68) cases detected in hospitalised patients in a tertiary care university hospital in Spain, October 2014.

PubMed

Gimferrer, Laura; Campins, Magda; Codina, Maria Gema; Esperalba, Juliana; Martin, Maria Del Carmen; Fuentes, Francisco; Pumarola, Tomas; Anton, Andres

2015-11-01

Several outbreaks of Enterovirus 68 (EV-D68) have recently been reported in the USA and Canada, causing substantial hospitalisation of children with severe respiratory disease. The acute flaccid paralysis detected in the USA and Canada among children with EV-D68 infection has raised concerns about the aetiological role of this EV serotype in severe neurological disease. The circulation of EV-D68 in the general European population seems to be low, but European Centre for Disease Prevention and Control (ECDC) recommends being vigilant to new cases, particularly in severely ill hospitalised patients. In October 2014, enteroviruses were detected in respiratory samples collected from five hospitalised patients, children and adults. Phylogenetic analysis of partial VP1 sequences confirmed that the detected enteroviruses belonged to the D68 serotype, which were also similar to strains reported in USA (2014). However, all five patients developed respiratory symptoms, but only one required ICU admission. None of the patients described had symptoms of neurological disease. Other considerations related to the detection methods used for the diagnosis of respiratory enteroviruses are also discussed. In conclusion, additional evidence has been provided that supports the role of EV-D68 in respiratory infections in hospitalised patients. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Detection and proteomic characterization of extracellular vesicles in human pancreatic juice.

PubMed

Osteikoetxea, Xabier; Benke, Márton; Rodriguez, Marta; Pálóczi, Krisztina; Sódar, Barbara W; Szvicsek, Zsuzsanna; Szabó-Taylor, Katalin; Vukman, Krisztina V; Kittel, Ágnes; Wiener, Zoltán; Vékey, Károly; Harsányi, László; Szűcs, Ákos; Turiák, Lilla; Buzás, Edit I

2018-04-30

The prognosis of patients with pancreatic cancer has remained virtually unchanged with a high mortality rate compared to other types of cancers. An earlier detection would provide a time window of opportunity for treatment and prevention of deaths. In the present study we investigated extracellular vesicle (EV)-associated potential biomarkers for pancreatic cancer by directly assessing EV size-based subpopulations in pancreatic juice samples of patients with chronic pancreatitis or pancreatic cancer. In addition, we also studied blood plasma and pancreatic cancer cell line-derived EVs. Comparative proteomic analysis was performed of 102 EV preparations from human pancreatic juices, blood, and pancreatic cancer cell lines Capan-1 and MIA PaCa-2. EV preparations were also characterized by electron microscopy, tunable resistive pulse sensing, and flow cytometry. Here we describe the presence of EVs in human pancreatic juice samples. Pancreatic juice EV-associated proteins that we identified as possible candidate markers for pancreatic cancer included mucins, such as MUC1, MUC4, MUC5AC, MUC6 and MUC16, CFTR, and MDR1 proteins. These candidate biomarkers could also be detected by flow cytometry in EVs found in pancreatic juice and those secreted by pancreatic cancer cell lines. Together our data show that detection and characterization of EVs directly in pancreatic juice is feasible and may prove to be a valuable source of potential biomarkers of pancreatic cancer. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Cancer-derived extracellular vesicles: friend and foe of tumour immunosurveillance.

PubMed

Dörsam, Bastian; Reiners, Kathrin S; von Strandmann, Elke Pogge

2018-01-05

Extracellular vesicles (EVs) are important players of intercellular signalling mechanisms, including communication with and among immune cells. EVs can affect the surrounding tissue as well as peripheral cells. Recently, EVs have been identified to be involved in the aetiology of several diseases, including cancer. Tumour cell-released EVs or exosomes have been shown to promote a tumour-supporting environment in non-malignant tissue and, thus, benefit metastasis. The underlying mechanisms are numerous: loss of antigen expression, direct suppression of immune effector cells, exchange of nucleic acids, alteration of the recipient cells' transcription and direct suppression of immune cells. Consequently, tumour cells can subvert the host's immune detection as well as suppress the immune system. On the contrary, recent studies reported the existence of EVs able to activate immune cells, thus promoting the tumour-directed immune response. In this article, the immunosuppressive capabilities of EVs, on the one hand, and their potential use in immunoactivation and therapeutic potential, on the other hand, are discussed.This article is part of the discussion meeting issue 'Extracellular vesicles and the tumour microenvironment'. © 2017 The Authors.

Effect of spin-orbit and on-site Coulomb interactions on the electronic structure and lattice dynamics of uranium monocarbide

NASA Astrophysics Data System (ADS)

Wdowik, U. D.; Piekarz, P.; Legut, D.; Jagło, G.

2016-08-01

Uranium monocarbide, a potential fuel material for the generation IV reactors, is investigated within density functional theory. Its electronic, magnetic, elastic, and phonon properties are analyzed and discussed in terms of spin-orbit interaction and localized versus itinerant behavior of the 5 f electrons. The localization of the 5 f states is tuned by varying the local Coulomb repulsion interaction parameter. We demonstrate that the theoretical electronic structure, elastic constants, phonon dispersions, and their densities of states can reproduce accurately the results of x-ray photoemission and bremsstrahlung isochromat measurements as well as inelastic neutron scattering experiments only when the 5 f states experience the spin-orbit interaction and simultaneously remain partially localized. The partial localization of the 5 f electrons could be represented by a moderate value of the on-site Coulomb interaction parameter of about 2 eV. The results of the present studies indicate that both strong electron correlations and spin-orbit effects are crucial for realistic theoretical description of the ground-state properties of uranium carbide.

A multi-factor GIS method to identify optimal geographic locations for electric vehicle (EV) charging stations

NASA Astrophysics Data System (ADS)

Zhang, Yongqin; Iman, Kory

2018-05-01

Fuel-based transportation is one of the major contributors to poor air quality in the United States. Electric Vehicle (EV) is potentially the cleanest transportation technology to our environment. This research developed a spatial suitability model to identify optimal geographic locations for installing EV charging stations for travelling public. The model takes into account a variety of positive and negative factors to identify prime locations for installing EV charging stations in Wasatch Front, Utah, where automobile emission causes severe air pollution due to atmospheric inversion condition near the valley floor. A walkable factor grid was created to store index scores from input factor layers to determine prime locations. 27 input factors including land use, demographics, employment centers etc. were analyzed. Each factor layer was analyzed to produce a summary statistic table to determine the site suitability. Potential locations that exhibit high EV charging usage were identified and scored. A hot spot map was created to demonstrate high, moderate, and low suitability areas for installing EV charging stations. A spatially well distributed EV charging system was then developed, aiming to reduce "range anxiety" from traveling public. This spatial methodology addresses the complex problem of locating and establishing a robust EV charging station infrastructure for decision makers to build a clean transportation infrastructure, and eventually improve environment pollution.

A clinically authentic mouse model of enterovirus 71 (EV-A71)-induced neurogenic pulmonary oedema.

PubMed

Victorio, Carla Bianca Luena; Xu, Yishi; Ng, Qimei; Chua, Beng Hooi; Alonso, Sylvie; Chow, Vincent T K; Chua, Kaw Bing

2016-06-30

Enterovirus 71 (EV-A71) is a neurotropic virus that sporadically causes fatal neurologic illness among infected children. Animal models of EV-A71 infection exist, but they do not recapitulate in animals the spectrum of disease and pathology observed in fatal human cases. Specifically, neurogenic pulmonary oedema (NPE)-the main cause of EV-A71 infection-related mortality-is not observed in any of these models. This limits their utility in understanding viral pathogenesis of neurologic infections. We report the development of a mouse model of EV-A71 infection displaying NPE in severely affected animals. We inoculated one-week-old BALB/c mice with an adapted EV-A71 strain and identified clinical signs consistent with observations in human cases and other animal models. We also observed respiratory distress in some mice. At necropsy, we found their lungs to be heavier and incompletely collapsed compared to other mice. Serum levels of catecholamines and histopathology of lung and brain tissues of these mice strongly indicated onset of NPE. The localization of virally-induced brain lesions also suggested a potential pathogenic mechanism for EV-A71-induced NPE. This novel mouse model of virally-induced NPE represents a valuable resource for studying viral mechanisms of neuro-pathogenesis and pre-clinical testing of potential therapeutics and prophylactics against EV-A71-related neurologic complications.

InterEvDock: a docking server to predict the structure of protein–protein interactions using evolutionary information

PubMed Central

Yu, Jinchao; Vavrusa, Marek; Andreani, Jessica; Rey, Julien; Tufféry, Pierre; Guerois, Raphaël

2016-01-01

The structural modeling of protein–protein interactions is key in understanding how cell machineries cross-talk with each other. Molecular docking simulations provide efficient means to explore how two unbound protein structures interact. InterEvDock is a server for protein docking based on a free rigid-body docking strategy. A systematic rigid-body docking search is performed using the FRODOCK program and the resulting models are re-scored with InterEvScore and SOAP-PP statistical potentials. The InterEvScore potential was specifically designed to integrate co-evolutionary information in the docking process. InterEvDock server is thus particularly well suited in case homologous sequences are available for both binding partners. The server returns 10 structures of the most likely consensus models together with 10 predicted residues most likely involved in the interface. In 91% of all complexes tested in the benchmark, at least one residue out of the 10 predicted is involved in the interface, providing useful guidelines for mutagenesis. InterEvDock is able to identify a correct model among the top10 models for 49% of the rigid-body cases with evolutionary information, making it a unique and efficient tool to explore structural interactomes under an evolutionary perspective. The InterEvDock web interface is available at http://bioserv.rpbs.univ-paris-diderot.fr/services/InterEvDock/. PMID:27131368

Potentials and capabilities of the Extracellular Vesicle (EV) Array.

PubMed

Jørgensen, Malene Møller; Bæk, Rikke; Varming, Kim

2015-01-01

Extracellular vesicles (EVs) and exosomes are difficult to enrich or purify from biofluids, hence quantification and phenotyping of these are tedious and inaccurate. The multiplexed, highly sensitive and high-throughput platform of the EV Array presented by Jørgensen et al., (J Extracell Vesicles, 2013; 2: 10) has been refined regarding the capabilities of the method for characterization and molecular profiling of EV surface markers. Here, we present an extended microarray platform to detect and phenotype plasma-derived EVs (optimized for exosomes) for up to 60 antigens without any enrichment or purification prior to analysis.

Co-circulation of multiple subtypes of enterovirus A71 (EV- A71) genotype C, including novel recombinants characterised by use of whole genome sequencing (WGS), Denmark 2016.

PubMed

Midgley, Sofie E; Nielsen, Astrid G; Trebbien, Ramona; Poulsen, Mille W; Andersen, Peter H; Fischer, Thea K

2017-06-29

In Europe, enterovirus A71 (EV-A71) has primarily been associated with sporadic cases of neurological disease. The recent emergence of new genotypes and larger outbreaks with severely ill patients demonstrates a potential for the spread of new, highly pathogenic EV-A71 strains. Detection and characterisation of these new emerging EV variants is challenging as standard EV assays may not be adequate, necessitating the use of whole genome analysis. This article is copyright of The Authors, 2017.

Computational tests of quantum chemical models for excited and ionized states of molecules with phosphorus and sulfur atoms.

PubMed

Hahn, David K; RaghuVeer, Krishans; Ortiz, J V

2014-05-15

Time-dependent density functional theory (TD-DFT) and electron propagator theory (EPT) are used to calculate the electronic transition energies and ionization energies, respectively, of species containing phosphorus or sulfur. The accuracy of TD-DFT and EPT, in conjunction with various basis sets, is assessed with data from gas-phase spectroscopy. TD-DFT is tested using 11 prominent exchange-correlation functionals on a set of 37 vertical and 19 adiabatic transitions. For vertical transitions, TD-CAM-B3LYP calculations performed with the MG3S basis set are lowest in overall error, having a mean absolute deviation from experiment of 0.22 eV, or 0.23 eV over valence transitions and 0.21 eV over Rydberg transitions. Using a larger basis set, aug-pc3, improves accuracy over the valence transitions via hybrid functionals, but improved accuracy over the Rydberg transitions is only obtained via the BMK functional. For adiabatic transitions, all hybrid functionals paired with the MG3S basis set perform well, and B98 is best, with a mean absolute deviation from experiment of 0.09 eV. The testing of EPT used the Outer Valence Green's Function (OVGF) approximation and the Partial Third Order (P3) approximation on 37 vertical first ionization energies. It is found that OVGF outperforms P3 when basis sets of at least triple-ζ quality in the polarization functions are used. The largest basis set used in this study, aug-pc3, obtained the best mean absolute error from both methods -0.08 eV for OVGF and 0.18 eV for P3. The OVGF/6-31+G(2df,p) level of theory is particularly cost-effective, yielding a mean absolute error of 0.11 eV.

Atomic-Scale Simulation of Electrochemical Processes at Electrode/Water Interfaces under Referenced Bias Potential.

PubMed

Bouzid, Assil; Pasquarello, Alfredo

2018-04-19

Based on constant Fermi-level molecular dynamics and a proper alignment scheme, we perform simulations of the Pt(111)/water interface under variable bias potential referenced to the standard hydrogen electrode (SHE). Our scheme yields a potential of zero charge μ pzc of ∼0.22 eV relative to the SHE and a double layer capacitance C dl of ≃19 μF cm -2 , in excellent agreement with experimental measurements. In addition, we study the structural reorganization of the electrical double layer for bias potentials ranging from -0.92 eV to +0.44 eV and find that O down configurations, which are dominant at potentials above the pzc, reorient to favor H down configurations as the measured potential becomes negative. Our modeling scheme allows one to not only access atomic-scale processes at metal/water interfaces, but also to quantitatively estimate macroscopic electrochemical quantities.

An enhanced Enterovirus surveillance system allows identification and characterization of rare and emerging respiratory enteroviruses in Denmark, 2015-16.

PubMed

Barnadas, Céline; Midgley, Sofie E; Skov, Marianne N; Jensen, Lotte; Poulsen, Mille W; Fischer, Thea Kølsen

2017-08-01

The potential for outbreaks due to Enteroviruses (EV) with respiratory tropism, such as EV-D68, and the detection of new and rare EV species C is a concern. These EVs are typically not detected in stool specimens and may therefore be missed by standard EV surveillance systems. Following the North American outbreak of EV-D68 in 2014, Denmark piloted an enhanced EV surveillance system that included the screening of respiratory samples. We aim to report clinical manifestations and phylogenetic descriptions from the rare and emerging EVs identified thereby demonstrating the usefulness of this system. Positive EV samples received through the enhanced non-polio EV pilot surveillance system were characterized by sequencing fragments of VP1, VP2 and VP4 capsid proteins and clinical observations were compiled. Between January 2015 and October 2016, six cases of rare genotypes EV-C104, C105 and C109 and nine cases of EV-D68 were identified. Patients presented with mild to moderately severe respiratory illness; no paralysis occurred. Distinct EV-C104, EV-C109 and EV-D68 sequences argue against a common source of introduction of these genotypes in the Danish population. The enhanced EV surveillance system enabled detection and characterization of rare EVs in Denmark. In order to improve our knowledge of and our preparedness against emerging EVs, public health laboratories should consider expanding their EV surveillance system to include respiratory specimens. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibition of enterovirus 71 (EV-71) infections by a novel antiviral peptide derived from EV-71 capsid protein VP1.

PubMed

Tan, Chee Wah; Chan, Yoke Fun; Sim, Kooi Mow; Tan, Eng Lee; Poh, Chit Laa

2012-01-01

Enterovirus 71 (EV-71) is the main causative agent of hand, foot and mouth disease (HFMD). In recent years, EV-71 infections were reported to cause high fatalities and severe neurological complications in Asia. Currently, no effective antiviral or vaccine is available to treat or prevent EV-71 infection. In this study, we have discovered a synthetic peptide which could be developed as a potential antiviral for inhibition of EV-71. Ninety five synthetic peptides (15-mers) overlapping the entire EV-71 capsid protein, VP1, were chemically synthesized and tested for antiviral properties against EV-71 in human Rhabdomyosarcoma (RD) cells. One peptide, SP40, was found to significantly reduce cytopathic effects of all representative EV-71 strains from genotypes A, B and C tested, with IC(50) values ranging from 6-9.3 µM in RD cells. The in vitro inhibitory effect of SP40 exhibited a dose dependent concentration corresponding to a decrease in infectious viral particles, total viral RNA and the levels of VP1 protein. The antiviral activity of SP40 peptide was not restricted to a specific cell line as inhibition of EV-71 was observed in RD, HeLa, HT-29 and Vero cells. Besides inhibition of EV-71, it also had antiviral activities against CV-A16 and poliovirus type 1 in cell culture. Mechanism of action studies suggested that the SP40 peptide was not virucidal but was able to block viral attachment to the RD cells. Substitutions of arginine and lysine residues with alanine in the SP40 peptide at positions R3A, R4A, K5A and R13A were found to significantly decrease antiviral activities, implying the importance of positively charged amino acids for the antiviral activities. The data demonstrated the potential and feasibility of SP40 as a broad spectrum antiviral agent against EV-71.

Hookworm Secreted Extracellular Vesicles Interact With Host Cells and Prevent Inducible Colitis in Mice

PubMed Central

Eichenberger, Ramon M.; Ryan, Stephanie; Jones, Linda; Buitrago, Geraldine; Polster, Ramona; Montes de Oca, Marcela; Zuvelek, Jennifer; Giacomin, Paul R.; Dent, Lindsay A.; Engwerda, Christian R.; Field, Matthew A.; Sotillo, Javier; Loukas, Alex

2018-01-01

Gastrointestinal (GI) parasites, hookworms in particular, have evolved to cause minimal harm to their hosts, allowing them to establish chronic infections. This is mediated by creating an immunoregulatory environment. Indeed, hookworms are such potent suppressors of inflammation that they have been used in clinical trials to treat inflammatory bowel diseases (IBD) and celiac disease. Since the recent description of helminths (worms) secreting extracellular vesicles (EVs), exosome-like EVs from different helminths have been characterized and their salient roles in parasite–host interactions have been highlighted. Here, we analyze EVs from the rodent parasite Nippostrongylus brasiliensis, which has been used as a model for human hookworm infection. N. brasiliensis EVs (Nb-EVs) are actively internalized by mouse gut organoids, indicating a role in driving parasitism. We used proteomics and RNA-Seq to profile the molecular composition of Nb-EVs. We identified 81 proteins, including proteins frequently present in exosomes (like tetraspanin, enolase, 14-3-3 protein, and heat shock proteins), and 27 sperm-coating protein-like extracellular proteins. RNA-Seq analysis revealed 52 miRNA species, many of which putatively map to mouse genes involved in regulation of inflammation. To determine whether GI nematode EVs had immunomodulatory properties, we assessed their potential to suppress GI inflammation in a mouse model of inducible chemical colitis. EVs from N. brasiliensis but not those from the whipworm Trichuris muris or control vesicles from grapes protected against colitic inflammation in the gut of mice that received a single intraperitoneal injection of EVs. Key cytokines associated with colitic pathology (IL-6, IL-1β, IFNγ, and IL-17a) were significantly suppressed in colon tissues from EV-treated mice. By contrast, high levels of the anti-inflammatory cytokine IL-10 were detected in Nb-EV-treated mice. Proteins and miRNAs contained within helminth EVs hold great potential application in development of drugs to treat helminth infections as well as chronic non-infectious diseases resulting from a dysregulated immune system, such as IBD. PMID:29760697

Extracellular Vesicles in Cardiovascular Theranostics

PubMed Central

Bei, Yihua; Das, Saumya; Rodosthenous, Rodosthenis S.; Holvoet, Paul; Vanhaverbeke, Maarten; Monteiro, Marta Chagas; Monteiro, Valter Vinicius Silva; Radosinska, Jana; Bartekova, Monika; Jansen, Felix; Li, Qian; Rajasingh, Johnson; Xiao, Junjie

2017-01-01

Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells. Increasing evidence has shown the important regulatory effects of EVs in cardiovascular diseases (CVDs). EVs secreted by cardiomyocytes, endothelial cells, fibroblasts, and stem cells play essential roles in pathophysiological processes such as cardiac hypertrophy, cardiomyocyte survival and apoptosis, cardiac fibrosis, and angiogenesis in relation to CVDs. In this review, we will first outline the current knowledge about the physical characteristics, biological contents, and isolation methods of EVs. We will then focus on the functional roles of cardiovascular EVs and their pathophysiological effects in CVDs, as well as summarize the potential of EVs as therapeutic agents and biomarkers for CVDs. Finally, we will discuss the specific application of EVs as a novel drug delivery system and the utility of EVs in the field of regenerative medicine. PMID:29158817

Systematic Methodological Evaluation of a Multiplex Bead-Based Flow Cytometry Assay for Detection of Extracellular Vesicle Surface Signatures

PubMed Central

Wiklander, Oscar P. B.; Bostancioglu, R. Beklem; Welsh, Joshua A.; Zickler, Antje M.; Murke, Florian; Corso, Giulia; Felldin, Ulrika; Hagey, Daniel W.; Evertsson, Björn; Liang, Xiu-Ming; Gustafsson, Manuela O.; Mohammad, Dara K.; Wiek, Constanze; Hanenberg, Helmut; Bremer, Michel; Gupta, Dhanu; Björnstedt, Mikael; Giebel, Bernd; Nordin, Joel Z.; Jones, Jennifer C.; EL Andaloussi, Samir; Görgens, André

2018-01-01

Extracellular vesicles (EVs) can be harvested from cell culture supernatants and from all body fluids. EVs can be conceptually classified based on their size and biogenesis as exosomes and microvesicles. Nowadays, it is however commonly accepted in the field that there is a much higher degree of heterogeneity within these two subgroups than previously thought. For instance, the surface marker profile of EVs is likely dependent on the cell source, the cell’s activation status, and multiple other parameters. Within recent years, several new methods and assays to study EV heterogeneity in terms of surface markers have been described; most of them are being based on flow cytometry. Unfortunately, such methods generally require dedicated instrumentation, are time-consuming and demand extensive operator expertise for sample preparation, acquisition, and data analysis. In this study, we have systematically evaluated and explored the use of a multiplex bead-based flow cytometric assay which is compatible with most standard flow cytometers and facilitates a robust semi-quantitative detection of 37 different potential EV surface markers in one sample simultaneously. First, assay variability, sample stability over time, and dynamic range were assessed together with the limitations of this assay in terms of EV input quantity required for detection of differently abundant surface markers. Next, the potential effects of EV origin, sample preparation, and quality of the EV sample on the assay were evaluated. The findings indicate that this multiplex bead-based assay is generally suitable to detect, quantify, and compare EV surface signatures in various sample types, including unprocessed cell culture supernatants, cell culture-derived EVs isolated by different methods, and biological fluids. Furthermore, the use and limitations of this assay to assess heterogeneities in EV surface signatures was explored by combining different sets of detection antibodies in EV samples derived from different cell lines and subsets of rare cells. Taken together, this validated multiplex bead-based flow cytometric assay allows robust, sensitive, and reproducible detection of EV surface marker expression in various sample types in a semi-quantitative way and will be highly valuable for many researchers in the EV field in different experimental contexts.

Systematic Methodological Evaluation of a Multiplex Bead-Based Flow Cytometry Assay for Detection of Extracellular Vesicle Surface Signatures.

PubMed

Wiklander, Oscar P B; Bostancioglu, R Beklem; Welsh, Joshua A; Zickler, Antje M; Murke, Florian; Corso, Giulia; Felldin, Ulrika; Hagey, Daniel W; Evertsson, Björn; Liang, Xiu-Ming; Gustafsson, Manuela O; Mohammad, Dara K; Wiek, Constanze; Hanenberg, Helmut; Bremer, Michel; Gupta, Dhanu; Björnstedt, Mikael; Giebel, Bernd; Nordin, Joel Z; Jones, Jennifer C; El Andaloussi, Samir; Görgens, André

2018-01-01

Extracellular vesicles (EVs) can be harvested from cell culture supernatants and from all body fluids. EVs can be conceptually classified based on their size and biogenesis as exosomes and microvesicles. Nowadays, it is however commonly accepted in the field that there is a much higher degree of heterogeneity within these two subgroups than previously thought. For instance, the surface marker profile of EVs is likely dependent on the cell source, the cell's activation status, and multiple other parameters. Within recent years, several new methods and assays to study EV heterogeneity in terms of surface markers have been described; most of them are being based on flow cytometry. Unfortunately, such methods generally require dedicated instrumentation, are time-consuming and demand extensive operator expertise for sample preparation, acquisition, and data analysis. In this study, we have systematically evaluated and explored the use of a multiplex bead-based flow cytometric assay which is compatible with most standard flow cytometers and facilitates a robust semi-quantitative detection of 37 different potential EV surface markers in one sample simultaneously. First, assay variability, sample stability over time, and dynamic range were assessed together with the limitations of this assay in terms of EV input quantity required for detection of differently abundant surface markers. Next, the potential effects of EV origin, sample preparation, and quality of the EV sample on the assay were evaluated. The findings indicate that this multiplex bead-based assay is generally suitable to detect, quantify, and compare EV surface signatures in various sample types, including unprocessed cell culture supernatants, cell culture-derived EVs isolated by different methods, and biological fluids. Furthermore, the use and limitations of this assay to assess heterogeneities in EV surface signatures was explored by combining different sets of detection antibodies in EV samples derived from different cell lines and subsets of rare cells. Taken together, this validated multiplex bead-based flow cytometric assay allows robust, sensitive, and reproducible detection of EV surface marker expression in various sample types in a semi-quantitative way and will be highly valuable for many researchers in the EV field in different experimental contexts.

Cellular tropism of human enterovirus D species serotypes EV-94, EV-70, and EV-68 in vitro: implications for pathogenesis.

PubMed

Smura, Teemu; Ylipaasto, Petri; Klemola, Päivi; Kaijalainen, Svetlana; Kyllönen, Lauri; Sordi, Valeria; Piemonti, Lorenzo; Roivainen, Merja

2010-11-01

Enterovirus 94 (EV-94) is an enterovirus serotype described recently which, together with EV-68 and EV-70, forms human enterovirus D species. This study investigates the seroprevalences of these three serotypes and their abilities to infect, replicate, and damage cell types considered to be essential for enterovirus-induced diseases. The cell types studied included human leukocyte cell lines, primary endothelial cells, and pancreatic islets. High prevalence of neutralizing antibodies against EV-68 and EV-94 was found in the Finnish population. The virus strains studied had wide leukocyte tropism. EV-94 and EV-68 were able to produce infectious progeny in leukocyte cell lines with monocytic, granulocytic, T-cell, or B-cell characteristics. EV-94 and EV-70 were capable of infecting primary human umbilical vein endothelial cells, whereas EV-68 had only marginal progeny production and did not induce cytopathic effects in these cells. Intriguingly, EV-94 was able to damage pancreatic islet β-cells, to infect, replicate, and cause necrosis in human pancreatic islets, and to induce proinflammatory and chemoattractive cytokine expression in endothelial cells. These results suggest that HEV-D viruses may be more prevalent than has been thought previously, and they provide in vitro evidence that EV-94 may be a potent pathogen and should be considered a potentially diabetogenic enterovirus type. © 2010 Wiley-Liss, Inc.

The effect of storage temperature on the biological activity of extracellular vesicles for the complement system.

PubMed

Park, Sang June; Jeon, Hyungtaek; Yoo, Seung-Min; Lee, Myung-Shin

2018-05-10

Extracellular vesicles (EVs) are mediators of intercellular communication by transporting cargo containing proteins, lipids, mRNA, and miRNA. There is increasing evidence that EVs have various roles in regulating migration, invasion, stemness, survival, and immune functions. Previously, we have found that EVs from Kaposi's sarcoma-associated herpesvirus (KSHV)-infected human endothelial cells have the potential to activate the complement system. Although many studies have shown that the physical properties of EVs can be changed by their storage condition, there have been few studies for the stability of biological activity of EVs in various storage conditions. In this study, we investigated various conditions to identify the best conditions to store EVs with functional stability for 25 d. Furthermore, the correlation between the function and other characteristics of EVs, including the expression of EV markers, size distribution, and particle number, were also analyzed. Our results demonstrated that storage temperature is an important factor to maintain the activity of EVs and would be useful information for basic research and clinical application using EVs.

Thermoelectric properties of 2H-CuGaO2 for device applications: A first principle TB-mBJ potential study

NASA Astrophysics Data System (ADS)

Bhamu, K. C.; Praveen, C. S.

2017-12-01

Here we report the structural, electronic, optical, and thermoelectric properties of delafossite type 2H-CuGaO2 using first principles calculations. The present calculation predict an indirect band gap of 1.20 eV and a direct band gap of 3.48 eV. A detailed analysis of the electronic structure is provided based on atom and orbital projected density of states. Frequency dependent dielectric functions, refractive index, and absorption coefficient as a function of photon energy are discussed. The thermoelectric properties with power factor, and the figure of merit are reported as a function of chemical potential in the region ± 0.195 (μ -EF) eV at constant temperature of 300 and 800 K. The thermoelectric properties shows that 2H-CuGaO2 could be potential candidate for engineering devises operating at high temperature for the chemical potential in the range of ± 0.055 (μ -EF) eV and beyond this range the thermoelectric performance of 2H-CuGaO2 get reduced.

Structural, optical and electrical properties of CeO2 thin films simultaneously prepared by anodic and cathodic electrodeposition

NASA Astrophysics Data System (ADS)

Yang, Yumeng; Du, Xiaoqing; Yi, Chenxi; Liu, Jiao; Zhu, Benfeng; Zhang, Zhao

2018-05-01

CeO2 thin films were deposited on stainless steel (SS) and indium tin oxide (ITO)-coated glass by simultaneous anodic and cathodic electrodeposition, and the influence of negative potential on the formation of ceria films was studied with scanning electron microscopy, X-ray diffraction, Raman spectroscopy, van der Pauw measurements, UV-visible spectroscopy and X-ray photoelectron spectroscopy. The results show that CeO2 films on the anode are slightly affected by the potential, but the particle size, crystal orientation, strain, film thickness, resistivity and Ce(III) content of the films on the cathode increases with increasing potential on the SS substrate. Contradictory to the results of the SS cathode, redshift (Ed changed from 3.95 eV to 3.56 eV and Ei changed from 3.42 eV to 3.04 eV) occurring in the absorption spectrum of CeO2 deposited on the ITO-coated glass cathode indicates that the content of Ce3+ in the cathodic films is dependent on the adopted substrates and decreases as the applied potential is increased.

Direct identification of non-polio enteroviruses in residual paralysis cases by analysis of VP1 sequences.

PubMed

Rahimi, Pooneh; Tabatabaie, H; Gouya, Mohammad M; Mahmudi, M; Musavi, T; Rad, K Samimi; Azad, T Mokhtari; Nategh, R

2009-06-01

The 66 serotypes of human enteroviruses (EVs) are classified into four species A-D, based on phylogenetic relationships in multiple genome regions. Partial VP(1) amplification and sequence analysis are reliable methods for identifying non-polio enterovirus serotypes, especially in negative cell culture specimens from patients with residual paralysis. In Iran during the years 2000-2002, there were 29 residual paralysis cases with negative cell (RD, HEp(2) and L(20)B) culture results. The genomic RNA was extracted from stool specimens from cases of residual paralysis and detected by amplification of the 5'-nontranslated region using RT-PCR with Pan-EV primers. Partial VP(1) amplification by semi-nested RT-PCR (snRT-PCR) and sequence analysis were done. Specimens from the 29 culture-negative cases contained echoviruses of six different serotypes. The global eradication of wild polioviruses is near and study of non-polio enteroviruses, which can cause poliomyelitis, is increasingly important to understand their pathogenesis. The VP(1) sequences, derived from the snRT-PCR products, allowed rapid molecular analysis of these non-polio strains.

Ab-initio Calculation of Optoelectronic and Structural Properties of Cubic Lithium Oxide (Li2O)

NASA Astrophysics Data System (ADS)

Ziegler, Joshua; Polin, Daniel; Malozovsky, Yuriy; Bagayoko, Diola

Using the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF), we performed ab-initio, density functional theory (DFT) calculations of optoelectronic, transport, and bulk properties of Li2S. In so doing, we avoid ``band gap'' and problems plaguing many DET calculations [AIP Advances 4, 127104 (2014)]. We employed a local density approximation (LDA) potential and the linear combination of atomic orbitals (LCAO). With the BZW-EF method, our results possess the full, physical content of DFT and agree with available, corresponding experimental ones. In particular, we found a room temperature indirect band gap of 6.659 eV that compares favorably with experimental values ranging from 5 to 7.99 eV. We also calculated total and partial density of states (DOS and PDOS), effective masses of charge carriers, the equilibrium lattice constant, and the bulk modulus. Acknowledgments: This work was funded in part by the National Science Foundation (NSF) and the Louisiana Board of Regents, through LASiGMA [Award Nos. EPS- 1003897, NSF (2010-15)-RII-SUBR] and NSF HRD-1002541, the US Department of Energy - National, Nuclear Security Administration (NNSA) (Award Nos. DE-NA0001861 and DE- NA0002630), LaSPACE, and LONI-SUBR.

Mesenchymal Stromal Cell-Derived Extracellular Vesicles Protect the Fetal Brain After Hypoxia-Ischemia.

PubMed

Ophelders, Daan R M G; Wolfs, Tim G A M; Jellema, Reint K; Zwanenburg, Alex; Andriessen, Peter; Delhaas, Tammo; Ludwig, Anna-Kristin; Radtke, Stefan; Peters, Vera; Janssen, Leon; Giebel, Bernd; Kramer, Boris W

2016-06-01

Preterm neonates are susceptible to perinatal hypoxic-ischemic brain injury, for which no treatment is available. In a preclinical animal model of hypoxic-ischemic brain injury in ovine fetuses, we have demonstrated the neuroprotective potential of systemically administered mesenchymal stromal cells (MSCs). The mechanism of MSC treatment is unclear but suggested to be paracrine, through secretion of extracellular vesicles (EVs). Therefore, we investigated in this study the protective effects of mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) in a preclinical model of preterm hypoxic-ischemic brain injury. Ovine fetuses were subjected to global hypoxia-ischemia by transient umbilical cord occlusion, followed by in utero intravenous administration of MSC-EVs. The therapeutic effects of MSC-EV administration were assessed by analysis of electrophysiological parameters and histology of the brain. Systemic administration of MSC-EVs improved brain function by reducing the total number and duration of seizures, and by preserving baroreceptor reflex sensitivity. These functional protections were accompanied by a tendency to prevent hypomyelination. Cerebral inflammation remained unaffected by the MSC-EV treatment. Our data demonstrate that MSC-EV treatment might provide a novel strategy to reduce the neurological sequelae following hypoxic-ischemic injury of the preterm brain. Our study results suggest that a cell-free preparation comprising neuroprotective MSC-EVs could substitute MSCs in the treatment of preterm neonates with hypoxic-ischemic brain injury, thereby circumventing the potential risks of systemic administration of living cells. Bone marrow-derived mesenchymal stromal cells (MSCs) show promise in treating hypoxic-ischemic injury of the preterm brain. Study results suggest administration of extracellular vesicles, rather than intact MSCs, is sufficient to exert therapeutic effects and avoids potential concerns associated with administration of living cells. The therapeutic efficacy of systemically administered mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) on hypoxia-ischemia-induced injury was assessed in the preterm ovine brain. Impaired function and structural injury of the fetal brain was improved following global hypoxia-ischemia. A cell-free preparation of MSC-EVs could substitute for the cellular counterpart in the treatment of preterm neonates with hypoxic-ischemic brain injury. This may open new clinical applications for "off-the-shelf" interventions with MSC-EVs. ©AlphaMed Press.

Minireview: Emerging Roles for Extracellular Vesicles in Diabetes and Related Metabolic Disorders

PubMed Central

Lakhter, Alexander J.

2015-01-01

Extracellular vesicles (EVs), membrane-contained vesicles released by most cell types, have attracted a large amount of research interest over the past decade. Because of their ability to transfer cargo via regulated processes, causing functional impacts on recipient cells, these structures may play important roles in cell-cell communication and have implications in the physiology of numerous organ systems. In addition, EVs have been described in most human biofluids and have wide potential as relatively noninvasive biomarkers of various pathologic conditions. Specifically, EVs produced by the pancreatic β-cell have been demonstrated to regulate physiologic and pathologic responses to β-cell stress, including β-cell proliferation and apoptosis. β-Cell EVs are also capable of interacting with immune cells and may contribute to the activation of autoimmune processes that trigger or propagate β-cell inflammation and destruction during the development of diabetes. EVs from adipose tissue have been shown to contribute to the development of the chronic inflammation and insulin resistance associated with obesity and metabolic syndrome via interactions with other adipose, liver, and muscle cells. Circulating EVs may also serve as biomarkers for metabolic derangements and complications associated with diabetes. This minireview describes the properties of EVs in general, followed by a more focused review of the literature describing EVs affecting the β-cell, β-cell autoimmunity, and the development of insulin resistance, which all have the potential to affect development of type 1 or type 2 diabetes. PMID:26393296

Electrical and optical properties of nitrogen doped SnO{sub 2} thin films deposited on flexible substrates by magnetron sputtering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Feng, E-mail: fangfeng@seu.edu.cn; Zhang, Yeyu; Wu, Xiaoqin

2015-08-15

Graphical abstract: The best SnO{sub 2}:N TCO film: about 80% transmittance and 9.1 × 10{sup −4} Ω cm. - Highlights: • Nitrogen-doped tin oxide film was deposited on PET by RF-magnetron sputtering. • Effects of oxygen partial pressure on the properties of thin films were investigated. • For SnO{sub 2}:N film, visible light transmittance was 80% and electrical resistivity was 9.1 × 10{sup −4} Ω cm. - Abstract: Nitrogen-doped tin oxide (SnO{sub 2}:N) thin films were deposited on flexible polyethylene terephthalate (PET) substrates at room temperature by RF-magnetron sputtering. Effects of oxygen partial pressure (0–4%) on electrical and optical propertiesmore » of thin films were investigated. Experimental results showed that SnO{sub 2}:N films were amorphous state, and O/Sn ratios of SnO{sub 2}:N films were deviated from the standard stoichiometry 2:1. Optical band gap of SnO{sub 2}:N films increased from approximately 3.10 eV to 3.42 eV as oxygen partial pressure increased from 0% to 4%. For SnO{sub 2}:N thin films deposited on PET, transmittance was about 80% in the visible light region. The best transparent conductive oxide (TCO) deposited on flexible PET substrates was SnO{sub 2}:N thin films preparing at 2% oxygen partial pressure, the transmittance was about 80% and electrical conductivity was about 9.1 × 10{sup −4} Ω cm.« less

Nuclear Protein Sam68 Interacts with the Enterovirus 71 Internal Ribosome Entry Site and Positively Regulates Viral Protein Translation.

PubMed

Zhang, Hua; Song, Lei; Cong, Haolong; Tien, Po

2015-10-01

Enterovirus 71 (EV71) recruits various cellular factors to assist in the replication and translation of its genome. Identification of the host factors involved in the EV71 life cycle not only will enable a better understanding of the infection mechanism but also has the potential to be of use in the development of antiviral therapeutics. In this study, we demonstrated that the cellular factor 68-kDa Src-associated protein in mitosis (Sam68) acts as an internal ribosome entry site (IRES) trans-acting factor (ITAF) that binds specifically to the EV71 5' untranslated region (5'UTR). Interaction sites in both the viral IRES (stem-loops IV and V) and the heterogeneous nuclear ribonucleoprotein K homology (KH) domain of Sam68 protein were further mapped using an electrophoretic mobility shift assay (EMSA) and biotin RNA pulldown assay. More importantly, dual-luciferase (firefly) reporter analysis suggested that overexpression of Sam68 positively regulated IRES-dependent translation of virus proteins. In contrast, both IRES activity and viral protein translation significantly decreased in Sam68 knockdown cells compared with the negative-control cells treated with short hairpin RNA (shRNA). However, downregulation of Sam68 did not have a significant inhibitory effect on the accumulation of the EV71 genome. Moreover, Sam68 was redistributed from the nucleus to the cytoplasm and interacts with cellular factors, such as poly(rC)-binding protein 2 (PCBP2) and poly(A)-binding protein (PABP), during EV71 infection. The cytoplasmic relocalization of Sam68 in EV71-infected cells may be involved in the enhancement of EV71 IRES-mediated translation. Since Sam68 is known to be a RNA-binding protein, these results provide direct evidence that Sam68 is a novel ITAF that interacts with EV71 IRES and positively regulates viral protein translation. The nuclear protein Sam68 is found as an additional new host factor that interacts with the EV71 IRES during infection and could potentially enhance the translation of virus protein. To our knowledge, this is the first report that describes Sam68 actively participating in the life cycle of EV71 at a molecular level. These studies will not only improve our understanding of the replication of EV71 but also have the potential for aiding in developing a therapeutic strategy against EV71 infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Communication: Electron ionization of DNA bases.

PubMed

Rahman, M A; Krishnakumar, E

2016-04-28

No reliable experimental data exist for the partial and total electron ionization cross sections for DNA bases, which are very crucial for modeling radiation damage in genetic material of living cell. We have measured a complete set of absolute partial electron ionization cross sections up to 500 eV for DNA bases for the first time by using the relative flow technique. These partial cross sections are summed to obtain total ion cross sections for all the four bases and are compared with the existing theoretical calculations and the only set of measured absolute cross sections. Our measurements clearly resolve the existing discrepancy between the theoretical and experimental results, thereby providing for the first time reliable numbers for partial and total ion cross sections for these molecules. The results on fragmentation analysis of adenine supports the theory of its formation in space.

The combination effects of licl and the active leflunomide metabolite, A771726, on viral-induced interleukin 6 production and EV-A71 replication.

PubMed

Hung, Hui-Chen; Shih, Shin-Ru; Chang, Teng-Yuan; Fang, Ming-Yu; Hsu, John T-A

2014-01-01

Enterovirus 71 (EV-A71) is a neurotropic virus that can cause severe complications involving the central nervous system. No effective antiviral therapeutics are available for treating EV-A71 infection and drug discovery efforts are rarely focused to target this disease. Thus, the main goal of this study was to discover existing drugs with novel indications that may effectively inhibit EV-A71 replication and the inflammatory cytokines elevation. In this study, we showed that LiCl, a GSK3β inhibitor, effectively suppressed EV-A71 replication, apoptosis and inflammatory cytokines production (Interleukin 6, Interleukin-1β) in infected cells. Furthermore, LiCl and an immunomodular agent were shown to strongly synergize with each other in suppressing EV-A71 replication. The results highlighted potential new treatment regimens in suppressing sequelae caused by EV-A71 replication.

Cyclophilin A Associates with Enterovirus-71 Virus Capsid and Plays an Essential Role in Viral Infection as an Uncoating Regulator

PubMed Central

Huang, Jiaoyan; Yan, Wenzhong; Wang, Jinglan; Su, Dan; Ni, Cheng; Li, Jian; Rao, Zihe; Liu, Lei; Lou, Zhiyong

2014-01-01

Viruses utilize host factors for their efficient proliferation. By evaluating the inhibitory effects of compounds in our library, we identified inhibitors of cyclophilin A (CypA), a known immunosuppressor with peptidyl-prolyl cis-trans isomerase activity, can significantly attenuate EV71 proliferation. We demonstrated that CypA played an essential role in EV71 entry and that the RNA interference-mediated reduction of endogenous CypA expression led to decreased EV71 multiplication. We further revealed that CypA directly interacted with and modified the conformation of H-I loop of the VP1 protein in EV71 capsid, and thus regulated the uncoating process of EV71 entry step in a pH-dependent manner. Our results aid in the understanding of how host factors influence EV71 life cycle and provide new potential targets for developing antiviral agents against EV71 infection. PMID:25275585

Synthesis, characterization, computational studies and biological evaluation of S-benzyl-β-N-[3-(4-hydroxy-3-methoxy-phenylallylidene)]dithiocarbazate

NASA Astrophysics Data System (ADS)

Bhat, Rayees A.; Kumar, D.; Malla, Manzoor A.; Bhat, Sami U.; Khan, Md Shahzad; Manzoor, Ovais; Srivastava, Anurag; Naikoo, Rawoof A.; Mohsin, Mohd; Mir, Muzzaffar A.

2018-03-01

S-Benzyl-β-N-[3-(4-hydroxy-3-methoxy-phenylallylidene)]dithiocarbazate (HL1), Schiff base of S-benzyl dithiocarbazate, was synthesized by 1:1 condensation between S-benzyl dithiocarbazate and 4-hydroxy-3-methoxy cinnamaldehyde. The nitrogen-sulfur Schiff base (HL1) was characterized by Mass, FT-IR, H1-NMR, Raman, and UV-VIS spectroscopic techniques. Theoretical quantum chemical calculations were performed using DFT in combination with B3LYP exchange correlation functional and 6-311++ G (d, p) basis sets level. The calculated values of chemical potential (μ), HOMO-LUMO energy gap, chemical hardness, softness (S), ionization energy (IE), electron affinity (EA), dipole moment (D) and relative stabilization energy of the compound were 0.14881 eV, 0.12542 eV, 0.06271 eV, 3.37299 eV, -0.21152 eV, -0.08610 eV, 4.4090 Debye and -1753.350 eV respectively. Theoretically calculated parameters like H1-NMR, FT-IR, UV-VIS, Raman, electrostatic potential and HOMO-LUMO energy gap are in good agreement with experimental results. Also, in-vitro cytotoxicity studies were done against two habitually infection causing bacteria strains including gram-positive (S. aureus) and gram-negative (E. coli) for antibacterial activity. The results showed appreciable biological activity and the activity increased with increase in dose.

Disagreement between theory and experiment grows with increasing rotational excitation of HD(v', j') product for the H + D2 reaction.

PubMed

Jankunas, Justin; Sneha, Mahima; Zare, Richard N; Bouakline, Foudhil; Althorpe, Stuart C

2013-03-07

The Photoloc technique has been employed to measure the state-resolved differential cross sections of the HD(v', j(')) product in the reaction H + D2 over a wide range of collision energies and internal states. The experimental results were compared with fully dimensional, time-dependent quantum mechanical calculations on the refined Boothroyd-Keogh-Martin-Peterson potential energy surface. We find nearly perfect agreement between theory and experiment for HD(v', j(')) product states with low to medium rotational excitation, e.g., HD(v' = 1, j(') = 3) at a collision energy, Ecoll, of 1.72 eV, HD(v' = 1, j(') = 3, 5) at Ecoll = 1.97 eV, and HD(v' = 3, j(') = 3) at Ecoll = 1.97 eV. As the rotational angular momentum, j('), of HD(v', j(')) increases, the agreement between theoretical predictions and experimental measurements worsens but not in a simple fashion. A moderate disagreement between theory and experiment has been found for HD(v' = 0, j(') = 12) at Ecoll = 1.76 eV and increased monotonically for HD(v' = 0, j(') = 13) at Ecoll = 1.74 eV, HD(v' = 0, j(') = 14) at Ecoll = 1.72 eV, and HD(v' = 0, j(') = 15) at Ecoll = 1.70 eV. Disagreement was not limited to vibrationless HD(v', j(')) product states: HD(v' = 1, j(') = 12) at Ecoll = 1.60 eV and HD(v' = 3, j(') = 8, 10) at Ecoll = 1.97 eV followed a similar trend. Theoretical calculations suggest more sideways∕forward scattering than has been observed experimentally for high j(') HD(v', j(')) states. The source of this discrepancy is presently unknown but might be the result of inaccuracy in the potential energy surface.

Profiling extracellular vesicle release by the filarial nematode Brugia malayi reveals sex-specific differences in cargo and a sensitivity to ivermectin

PubMed Central

Harischandra, Hiruni; Yuan, Wang; Zamanian, Mostafa

2018-01-01

The filarial nematode Brugia malayi is an etiological agent of Lymphatic Filariasis. The capability of B. malayi and other parasitic nematodes to modulate host biology is recognized but the mechanisms by which such manipulation occurs are obscure. An emerging paradigm is the release of parasite-derived extracellular vesicles (EV) containing bioactive proteins and small RNA species that allow secretion of parasite effector molecules and their potential trafficking to host tissues. We have previously described EV release from the infectious L3 stage B. malayi and here we profile vesicle release across all intra-mammalian life cycle stages (microfilariae, L3, L4, adult male and female worms). Nanoparticle Tracking Analysis was used to quantify and size EVs revealing discrete vesicle populations and indicating a secretory process that is conserved across the life cycle. Brugia EVs are internalized by murine macrophages with no preference for life stage suggesting a uniform mechanism for effector molecule trafficking. Further, the use of chemical uptake inhibitors suggests all life stage EVs are internalized by phagocytosis. Proteomic profiling of adult male and female EVs using nano-scale LC-MS/MS described quantitative and qualitative differences in the adult EV proteome, helping define the biogenesis of Brugia EVs and revealing sexual dimorphic characteristics in immunomodulatory cargo. Finally, ivermectin was found to rapidly inhibit EV release by all Brugia life stages. Further this drug effect was also observed in the related filarial nematode, the canine heartworm Dirofilaria immitis but not in an ivermectin-unresponsive field isolate of that parasite, highlighting a potential mechanism of action for this drug and suggesting new screening platforms for anti-filarial drug development. PMID:29659599

Insights into the Diagnostic Potential of Extracellular Vesicles and Their miRNA Signature from Liquid Biopsy as Early Biomarkers of Diabetic Micro/Macrovascular Complications.

PubMed

La Marca, Valeria; Fierabracci, Alessandra

2017-09-14

Extracellular vesicles (EVs) represent a heterogeneous population of small vesicles, consisting of a phospholipidic bilayer surrounding a soluble interior cargo. Almost all cell types release EVs, thus they are naturally present in all body fluids. Among the several potential applications, EVs could be used as drug delivery vehicles in disease treatment, in immune therapy because of their immunomodulatory properties and in regenerative medicine. In addition to general markers, EVs are characterized by the presence of specific biomarkers (proteins and miRNAs) that allow the identification of their cell or tissue origin. For these features, they represent a potential powerful diagnostic tool to monitor state and progression of specific diseases. A large body of studies supports the idea that endothelial derived (EMPs) together with platelet-derived microparticles (PMPs) are deeply involved in the pathogenesis of diseases characterized by micro- and macrovascular damages, including diabetes. Existing literature suggests that the detection of circulating EMPs and PMPs and their specific miRNA profile may represent a very useful non-invasive signature to achieve information on the onset of peculiar disease manifestations. In this review, we discuss the possible utility of EVs in the early diagnosis of diabetes-associated microvascular complications, specifically related to kidney.

Where Do They Come from and Where Do They Go: Candidates for Regulating Extracellular Vesicle Formation in Fungi

PubMed Central

Oliveira, Débora L.; Rizzo, Juliana; Joffe, Luna S.; Godinho, Rodrigo M. C.; Rodrigues, Marcio L.

2013-01-01

In the past few years, extracellular vesicles (EVs) from at least eight fungal species were characterized. EV proteome in four fungal species indicated putative biogenesis pathways and suggested interesting similarities with mammalian exosomes. Moreover, as observed for mammalian exosomes, fungal EVs were demonstrated to be immunologically active. Here we review the seminal and most recent findings related to the production of EVs by fungi. Based on the current literature about secretion of fungal molecules and biogenesis of EVs in eukaryotes, we focus our discussion on a list of cellular proteins with the potential to regulate vesicle biogenesis in the fungi. PMID:23644887

Controlling enhanced absorption in graphene metamaterial

NASA Astrophysics Data System (ADS)

Zhou, Qihui; Liu, Peiguo; Bian, Li-an; Liu, Hanqing; Liu, Chenxi; Chen, Genghui

2018-04-01

In this paper, a controllable terahertz (THz) metamaterial absorber (MA) is designed with the circuit analog method. Taking advantage of the patterned graphene on SiO2/doped Si/polyimide substrates with a gold reflector, the controllable MA achieves perfect absorption at 0.75 THz. The chemical potential of graphene is regulated by controlling the voltage between graphene and doped Si layers. As the chemical potential varies from 0 eV to 0.5 eV, the MA is changed from reflection (<0.37) to absorption (>0.99). The distributions of surface current and electric field are illustrated to analyze the resonant characteristic of patterned graphene. According to the resonant characteristic, we introduce patterned graphene elements with different dimension in a unit cell, which effectively extends the effective absorption bandwidth (absorption > 0 . 9) from 0.67-0.93 THz to 0.52-0.95 THz. Moreover, replacing part of the graphene structure with gold, the switchable MA is turned into a frequency tunable MA. The absorption peak moves from 0.62 THz to 0.92 THz as the chemical potential increases from 0.1 eV to 0.5 eV. These designs overcome limitation of traditional absorbers and exhibit great potentials in many practical applications.

Fluorescence triggering: A general strategy for enumerating and phenotyping extracellular vesicles by flow cytometry.

PubMed

Arraud, Nicolas; Gounou, Céline; Turpin, Delphine; Brisson, Alain R

2016-02-01

Plasma contains cell-derived extracellular vesicles (EVs) which participate in various physiopathological processes and have potential biomedical applications. Despite intense research activity, knowledge on EVs is limited mainly due to the difficulty of isolating and characterizing sub-micrometer particles like EVs. We have recently reported that a simple flow cytometry (FCM) approach based on triggering the detection on a fluorescence signal enabled the detection of 50× more Annexin-A5 binding EVs (Anx5+ EVs) in plasma than the conventional FCM approach based on light scattering triggering. Here, we present the application of the fluorescence triggering approach to the enumeration and phenotyping of EVs from platelet free plasma (PFP), focusing on CD41+ and CD235a+ EVs, as well as their sub-populations which bind or do not bind Anx5. Higher EV concentrations were detected by fluorescence triggering as compared to light scattering triggering, namely 40× for Anx5+ EVs, 75× for CD41+ EVs, and 15× for CD235a+ EVs. We found that about 30% of Anx5+ EVs were of platelet origin while only 3% of them were of erythrocyte origin. In addition, a majority of EVs from platelet and erythrocyte origin do not expose PS, in contrast to the classical theory of EV formation. Furthermore, the same PFP samples were analyzed fresh and after freeze-thawing, showing that freeze-thawing processes induce an increase, of about 35%, in the amount of Anx5+ EVs, while the other EV phenotypes remain unchanged. The method of EV detection and phenotyping by fluorescence triggering is simple, sensitive and reliable. We foresee that its application to EV studies will improve our understanding on the formation mechanisms and functions of EVs in health and disease and help the development of EV-based biomarkers. © 2015 International Society for Advancement of Cytometry.

Circulation of multiple serotypes of highly divergent enterovirus C in the Xinjiang Uighur Autonomous Region of China

PubMed Central

Zhang, Yong; Sun, Qiang; Cui, Hui; Yan, Dongmei; Fan, Qin; Song, Yang; Zhu, Shuangli; Li, Xiaolei; Huang, Guohong; Ji, Tianjiao; Hu, Lan; Wang, Dongyan; Yang, Qian; Xu, Wenbo

2016-01-01

Poliomyelitis associated with circulating vaccine-derived polioviruses (cVDPVs) is a serious public health issue in the post-eradication era, and the occurrence of recombinant cVDPVs emphasizes the need to elucidate enterovirus C (EV-C) epidemiology. Stool samples were collected from 826 healthy children in Southern Xinjiang in 2011 to investigate EV-C circulation and epidemiology. Thirty-six EV-Cs were isolated and assigned to eight EV-C serotypes by molecular serotyping, suggesting the circulation of diverse EV-Cs in Xinjiang. Phylogenetic analysis showed that the Xinjiang EV-C strains had larger variation compared to the prototype and other modern strains. Additionally, the results showed unique characteristics of Xinjiang EV-Cs, such as the cytopathicity of CV-A1 strains to RD cells; the high divergence in CV-A11, CV-A13, CV-A17, and CV-A20 strains; the divergence of Xinjiang CV-A24 from AHC-related CV-A24 variant stains distributed worldwide; and the circulation of two novel EV-C serotypes (EV-C96 and EV-C99). Evaluations of this dense and diverse EV-C ecosystem will help elucidate the processes shaping enteroviral biodiversity. This study will improve our understanding of the evolution of enteroviruses and the recombination potential between polioviruses and other EV-Cs. PMID:27642136

Ab initio molecular dynamics simulations of AlN responding to low energy particle radiation

NASA Astrophysics Data System (ADS)

Xi, Jianqi; Liu, Bin; Zhang, Yanwen; Weber, William J.

2018-01-01

Ab initio molecular dynamics simulations of low energy recoil events in wurtzite AlN have been performed to determine threshold displacement energies, defect production and evolution mechanisms, role of partial charge transfer during the process, and the influence of irradiation-induced defects on the properties of AlN. The results show that the threshold displacement energies, Ed, along the direction parallel to the basal planes are smaller than those perpendicular to the basal planes. The minimum Ed values are determined to be 19 eV and 55 eV for N and Al atom, respectively, which occur along the [ 1 ¯ 1 ¯ 20 ] direction. In general, the threshold displacement energies for N are smaller than those for Al atom, indicating the N defects would be dominant under irradiation. The defect production mechanisms have been analyzed. It is found that charge transfer and redistribution for both the primary knock-on atom and the subsequent recoil atoms play a significant role in defect production and evolution. Similar to the trend in oxide materials, there is a nearly linear relationship between Ed and the total amount of charge transfer at the potential energy peak in AlN, which provides guidance on the development of charge-transfer interatomic potentials for classic molecular dynamics simulations. Finally, the response behavior of AlN to low energy irradiation is qualitatively investigated. The existence of irradiation-induced defects significantly modifies the electronic structure, and thus affects the magnetic, electronic and optical properties of AlN. These findings further enrich the understanding of defects in the wide bandgap semiconductor of AlN.

Nitrogen-doped partially reduced graphene oxide rewritable nonvolatile memory.

PubMed

Seo, Sohyeon; Yoon, Yeoheung; Lee, Junghyun; Park, Younghun; Lee, Hyoyoung

2013-04-23

As memory materials, two-dimensional (2D) carbon materials such as graphene oxide (GO)-based materials have attracted attention due to a variety of advantageous attributes, including their solution-processability and their potential for highly scalable device fabrication for transistor-based memory and cross-bar memory arrays. In spite of this, the use of GO-based materials has been limited, primarily due to uncontrollable oxygen functional groups. To induce the stable memory effect by ionic charges of a negatively charged carboxylic acid group of partially reduced graphene oxide (PrGO), a positively charged pyridinium N that served as a counterion to the negatively charged carboxylic acid was carefully introduced on the PrGO framework. Partially reduced N-doped graphene oxide (PrGODMF) in dimethylformamide (DMF) behaved as a semiconducting nonvolatile memory material. Its optical energy band gap was 1.7-2.1 eV and contained a sp2 C═C framework with 45-50% oxygen-functionalized carbon density and 3% doped nitrogen atoms. In particular, rewritable nonvolatile memory characteristics were dependent on the proportion of pyridinum N, and as the proportion of pyridinium N atom decreased, the PrGODMF film lost memory behavior. Polarization of charged PrGODMF containing pyridinium N and carboxylic acid under an electric field produced N-doped PrGODMF memory effects that followed voltage-driven rewrite-read-erase-read processes.

The B 1Πu potential energy curve and dissociation energy of 39K2

NASA Astrophysics Data System (ADS)

Heinze, Johannes; Engelke, Friedrich

1988-07-01

The 39K2 B 1Πu potential energy curve has been determined using laser spectroscopic techniques and quantum mechanical calculations. The dissociation energy is 2407.6±0.5 cm-1 (0.2985±0.0001 eV) including a potential barrier of 298±10 cm-1 (0.037±0.0013 eV) found with its maximum at 8.08±0.05 Å (15.3±0.1 bohr). The long-range behavior matches smoothly onto the form predicted from dispersion forces. The dissociation energy of the ground state X 1Σ+g, obtained by a long-range extrapolation of the vibrational separations, is De =4444±10 cm-1 (0.5506±0.0013 eV), in agreement with recent theoretical prediction.

PEGylated and targeted extracellular vesicles display enhanced cell specificity and circulation time.

PubMed

Kooijmans, S A A; Fliervoet, L A L; van der Meel, R; Fens, M H A M; Heijnen, H F G; van Bergen En Henegouwen, P M P; Vader, P; Schiffelers, R M

2016-02-28

Extracellular vesicles (EVs) are increasingly being recognized as candidate drug delivery systems due to their ability to functionally transfer biological cargo between cells. However, the therapeutic applicability of EVs may be limited due to a lack of cell-targeting specificity and rapid clearance of exogenous EVs from the circulation. In order to improve EV characteristics for drug delivery to tumor cells, we have developed a novel method for decorating EVs with targeting ligands conjugated to polyethylene glycol (PEG). Nanobodies specific for the epidermal growth factor receptor (EGFR) were conjugated to phospholipid (DMPE)-PEG derivatives to prepare nanobody-PEG-micelles. When micelles were mixed with EVs derived from Neuro2A cells or platelets, a temperature-dependent transfer of nanobody-PEG-lipids to the EV membranes was observed, indicative of a 'post-insertion' mechanism. This process did not affect EV morphology, size distribution, or protein composition. After introduction of PEG-conjugated control nanobodies to EVs, cellular binding was compromised due to the shielding properties of PEG. However, specific binding to EGFR-overexpressing tumor cells was dramatically increased when EGFR-specific nanobodies were employed. Moreover, whereas unmodified EVs were rapidly cleared from the circulation within 10min after intravenous injection in mice, EVs modified with nanobody-PEG-lipids were still detectable in plasma for longer than 60min post-injection. In conclusion, we propose post-insertion as a novel technique to confer targeting capacity to isolated EVs, circumventing the requirement to modify EV-secreting cells. Importantly, insertion of ligand-conjugated PEG-derivatized phospholipids in EV membranes equips EVs with improved cell specificity and prolonged circulation times, potentially increasing EV accumulation in targeted tissues and improving cargo delivery. Copyright © 2015. Published by Elsevier B.V.

Study of a coronagraphic mask using evanescent waves.

PubMed

Buisset, Christophe; Rabbia, Yves; Lepine, Thierry; Alagao, Mary-Angelie; Ducrot, Elsa; Poshyachinda, Saran; Soonthornthum, Boonrucksar

2017-04-03

The evanescent wave coronagraph (EvWaCo) is a specific kind of band-limited coronagraph using the frustrated total internal reflection phenomenon to produce the coronagraphic effect (removing starlight from the image plane in order to make the stellar environment detectable). In this paper, we present a theoretical and experimental study of the EvWaCo coronagraphic mask. First, we calculate the theoretical transmission and we show that this mask is partially achromatic. Then, we present the experimental results obtained in unpolarized light at the wavelength λ≈900 nm and relative spectral bandwidth Δλ/λ≈6%. In particular, we show that the coronagraph provides a contrast down to a few 10^-6 at an angular distance of about ten Airy radii.

DOE Office of Scientific and Technical Information (OSTI.GOV)

AlKhaldi, Mashaal Q.; Wehlitz, Ralf, E-mail: rwehlitz@gmail.com

We have experimentally investigated the double-photoionization process in C{sub 6}BrF{sub 5} using monochromatized synchrotron radiation. We compare our results with previously published data for partially deuterated benzene (C{sub 6}H{sub 3}D{sub 3}) over a wide range of photon energies from threshold to 270 eV. A broad resonance in the ratio of doubly to singly charged parent ions at about 65 eV appears shifted in energy compared to benzene data. This shift is due to the difference in the bond lengths in two molecules. A simple model can explain the shape of this resonance. At higher photon energies, we observe another broadmore » resonance that can be explained as a second harmonic of the first resonance.« less

First-principle calculations of electronic structures and polar properties of (κ,ε)-Ga2O3

NASA Astrophysics Data System (ADS)

Kim, Juyeong; Tahara, Daisuke; Miura, Yoshino; Kim, Bog G.

2018-06-01

Physical properties of κ- and ε-Ga2O3 are investigated using density functional theory. We utilized the supercell method considering the partial occupancies in ε-Ga2O3. The polarization values of these materials were analyzed to overcome the inconsistency between experimental and theoretical studies. The polarization values of κ- and ε-Ga2O3 were ∼26.39 and 24.44 µC/cm2, respectively. The bandgap values of 4.62 and 4.27 eV were estimated with the hybrid functional method, which suggested an underestimation of the PBEsol functional values of 2.32 and 2.06 eV for κ- and ε-Ga2O3, respectively.

Quasi-Particle Self-Consistent GW for Molecules.

PubMed

Kaplan, F; Harding, M E; Seiler, C; Weigend, F; Evers, F; van Setten, M J

2016-06-14

We present the formalism and implementation of quasi-particle self-consistent GW (qsGW) and eigenvalue only quasi-particle self-consistent GW (evGW) adapted to standard quantum chemistry packages. Our implementation is benchmarked against high-level quantum chemistry computations (coupled-cluster theory) and experimental results using a representative set of molecules. Furthermore, we compare the qsGW approach for five molecules relevant for organic photovoltaics to self-consistent GW results (scGW) and analyze the effects of the self-consistency on the ground state density by comparing calculated dipole moments to their experimental values. We show that qsGW makes a significant improvement over conventional G0W0 and that partially self-consistent flavors (in particular evGW) can be excellent alternatives.

Cancer cells copy migratory behavior and exchange signaling networks via extracellular vesicles.

PubMed

Steenbeek, Sander C; Pham, Thang V; de Ligt, Joep; Zomer, Anoek; Knol, Jaco C; Piersma, Sander R; Schelfhorst, Tim; Huisjes, Rick; Schiffelers, Raymond M; Cuppen, Edwin; Jimenez, Connie R; van Rheenen, Jacco

2018-06-14

Recent data showed that cancer cells from different tumor subtypes with distinct metastatic potential influence each other's metastatic behavior by exchanging biomolecules through extracellular vesicles (EVs). However, it is debated how small amounts of cargo can mediate this effect, especially in tumors where all cells are from one subtype, and only subtle molecular differences drive metastatic heterogeneity. To study this, we have characterized the content of EVs shed in vivo by two clones of melanoma (B16) tumors with distinct metastatic potential. Using the Cre-LoxP system and intravital microscopy, we show that cells from these distinct clones phenocopy their migratory behavior through EV exchange. By tandem mass spectrometry and RNA sequencing, we show that EVs shed by these clones into the tumor microenvironment contain thousands of different proteins and RNAs, and many of these biomolecules are from interconnected signaling networks involved in cellular processes such as migration. Thus, EVs contain numerous proteins and RNAs and act on recipient cells by invoking a multi-faceted biological response including cell migration. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Mapping Enterovirus A71 Antigenic Determinants from Viral Evolution.

PubMed

Huang, Sheng-Wen; Tai, Ching-Hui; Fonville, Judith M; Lin, Chin-Hui; Wang, Shih-Min; Liu, Ching-Chung; Su, Ih-Jen; Smith, Derek J; Wang, Jen-Ren

2015-11-01

Human enterovirus A71 (EV-A71) belongs to the Enterovirus A species in the Picornaviridae family. Several vaccines against EV-A71, a disease causing severe neurological complications or even death, are currently under development and being tested in clinical trials, and preventative vaccination programs are expected to start soon. To characterize the potential for antigenic change of EV-A71, we compared the sequences of two antigenically diverse genotype B4 and B5 strains of EV-A71 and identified substitutions at residues 98, 145, and 164 in the VP1 capsid protein as antigenic determinants. To examine the effects of these three substitutions on antigenicity, we constructed a series of recombinant viruses containing different mutation combinations at these three residues with a reverse genetics system and then investigated the molecular basis of antigenic changes with antigenic cartography. We found that a novel EV-A71 mutant, containing lysine, glutamine, and glutamic acid at the respective residues 98, 145, and 164 in the VP1 capsid protein, exhibited neutralization reduction against patients' antisera and substantially increased virus binding ability to human cells. These observations indicated that this low-neutralization-reactive EV-A71 VP1-98K/145Q/164E mutant potentially increases viral binding ability and that surveillance studies should look out for these mutants, which could compromise vaccine efficacy. Emerging and reemerging EV-A71 viruses can cause severe neurological etiology, primarily affecting children, especially around Asia-Pacific countries. We identified a set of mutations in EV-A71 that both reduced neutralization activity against humoral immunity in antisera of patients and healthy adults and greatly increased the viral binding ability to cells. These findings provide important insights for EV-A71 antigenic determinants and emphasize the importance of continuous surveillance, especially after EV-A71 vaccination programs begin. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mapping Enterovirus A71 Antigenic Determinants from Viral Evolution

PubMed Central

Huang, Sheng-Wen; Tai, Ching-Hui; Fonville, Judith M.; Lin, Chin-Hui; Wang, Shih-Min; Liu, Ching-Chung; Su, Ih-Jen

2015-01-01

ABSTRACT Human enterovirus A71 (EV-A71) belongs to the Enterovirus A species in the Picornaviridae family. Several vaccines against EV-A71, a disease causing severe neurological complications or even death, are currently under development and being tested in clinical trials, and preventative vaccination programs are expected to start soon. To characterize the potential for antigenic change of EV-A71, we compared the sequences of two antigenically diverse genotype B4 and B5 strains of EV-A71 and identified substitutions at residues 98, 145, and 164 in the VP1 capsid protein as antigenic determinants. To examine the effects of these three substitutions on antigenicity, we constructed a series of recombinant viruses containing different mutation combinations at these three residues with a reverse genetics system and then investigated the molecular basis of antigenic changes with antigenic cartography. We found that a novel EV-A71 mutant, containing lysine, glutamine, and glutamic acid at the respective residues 98, 145, and 164 in the VP1 capsid protein, exhibited neutralization reduction against patients' antisera and substantially increased virus binding ability to human cells. These observations indicated that this low-neutralization-reactive EV-A71 VP1-98K/145Q/164E mutant potentially increases viral binding ability and that surveillance studies should look out for these mutants, which could compromise vaccine efficacy. IMPORTANCE Emerging and reemerging EV-A71 viruses can cause severe neurological etiology, primarily affecting children, especially around Asia-Pacific countries. We identified a set of mutations in EV-A71 that both reduced neutralization activity against humoral immunity in antisera of patients and healthy adults and greatly increased the viral binding ability to cells. These findings provide important insights for EV-A71 antigenic determinants and emphasize the importance of continuous surveillance, especially after EV-A71 vaccination programs begin. PMID:26339057

Enterovirus 71 viral capsid protein linear epitopes: Identification and characterization

PubMed Central

2012-01-01

Background To characterize the human humoral immune response against enterovirus 71 (EV71) infection and map human epitopes on the viral capsid proteins. Methods A series of 256 peptides spanning the capsid proteins (VP1, VP2, VP3) of BJ08 strain (genomic C4) were synthesized. An indirect enzyme-linked immunosorbent assay (ELISA) was carried out to detect anti-EV71 IgM and IgG in sera of infected children in acute or recovery phase. The partially overlapped peptides contained 12 amino acids and were coated in the plate as antigen (0.1 μg/μl). Sera from rabbits immunized with inactivated BJ08 virus were also used to screen the peptide panel. Results A total of 10 human anti-EV71 IgM epitopes (vp1-14 in VP1; vp2-6, 21, 40 and 50 in VP2 and vp3-10, 12, 15, 24 and 75 in VP3) were identified in acute phase sera. In contrast, only one anti-EV71 IgG epitope in VP1 (vp1-15) was identified in sera of recovery stage. Four rabbit anti-EV71 IgG epitopes (vp1-14, 31, 54 and 71) were identified and mapped to VP1. Conclusion These data suggested that human IgM epitopes were mainly mapped to VP2 and VP3 with multi-epitope responses occurred at acute infection, while the only IgG epitope located on protein VP1 was activated in recovery phase sera. The dynamic changes of humoral immune response at different stages of infection may have public health significance in evaluation of EV71 vaccine immunogenicity and the clinical application of diagnostic reagents. PMID:22264266

Absolute total and partial dissociative cross sections of pyrimidine at electron and proton intermediate impact velocities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolff, Wania, E-mail: wania@if.ufrj.br; Luna, Hugo; Sigaud, Lucas

Absolute total non-dissociative and partial dissociative cross sections of pyrimidine were measured for electron impact energies ranging from 70 to 400 eV and for proton impact energies from 125 up to 2500 keV. MOs ionization induced by coulomb interaction were studied by measuring both ionization and partial dissociative cross sections through time of flight mass spectrometry and by obtaining the branching ratios for fragment formation via a model calculation based on the Born approximation. The partial yields and the absolute cross sections measured as a function of the energy combined with the model calculation proved to be a useful toolmore » to determine the vacancy population of the valence MOs from which several sets of fragment ions are produced. It was also a key point to distinguish the dissociation regimes induced by both particles. A comparison with previous experimental results is also presented.« less

Communication: Electron ionization of DNA bases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, M. A.; Krishnakumar, E., E-mail: ekkumar@tifr.res.in

2016-04-28

No reliable experimental data exist for the partial and total electron ionization cross sections for DNA bases, which are very crucial for modeling radiation damage in genetic material of living cell. We have measured a complete set of absolute partial electron ionization cross sections up to 500 eV for DNA bases for the first time by using the relative flow technique. These partial cross sections are summed to obtain total ion cross sections for all the four bases and are compared with the existing theoretical calculations and the only set of measured absolute cross sections. Our measurements clearly resolve themore » existing discrepancy between the theoretical and experimental results, thereby providing for the first time reliable numbers for partial and total ion cross sections for these molecules. The results on fragmentation analysis of adenine supports the theory of its formation in space.« less

Rapid and highly sensitive detection of Enterovirus 71 by using nanogold-enhanced electrochemical impedance spectroscopy

NASA Astrophysics Data System (ADS)

Li, Hsing-Yuan; Tseng, Shing-Hua; Cheng, Tsai-Mu; Chu, Hsueh-Liang; Lu, Yu-Ning; Wang, Fang-Yu; Tsai, Li-Yun; Shieh, Juo-Yu; Yang, Jyh-Yuan; Juan, Chien-Chang; Tu, Lung-Chen; Chang, Chia-Ching

2013-07-01

Enterovirus 71 (EV71) infection is an emerging infectious disease causing neurological complications and/or death within two to three days after the development of fever and rash. A low viral titre in clinical specimens makes the detection of EV71 difficult. Conventional approaches for detecting EV71 are time consuming, poorly sensitive, or complicated, and cannot be used effectively for clinical diagnosis. Furthermore, EV71 and Coxsackie virus A16 (CA16) may cross react in conventional assays. Therefore, a rapid, highly sensitive, specific, and user-friendly test is needed. We developed an EV71-specific nanogold-modified working electrode for electrochemical impedance spectroscopy in the detection of EV71. Our results show that EV71 can be distinguished from CA16, Herpes simplex virus, and lysozyme, with the modified nanogold electrode being able to detect EV71 in concentrations as low as 1 copy number/50 μl reaction volume, and the duration between sample preparation and detection being 11 min. This detection platform may have the potential for use in point-of-care diagnostics.

High sensitivity and label-free detection of Enterovirus 71 by nanogold modified electrochemical impedance spectroscopy

NASA Astrophysics Data System (ADS)

Wang, Fang-Yu; Li, Hsing-Yuan; Tseng, Shing-Hua; Cheng, Tsai-Mu; Chu, Hsueh-Liang; Yang, Jyh-Yuan; Chang, Chia-Ching

2013-03-01

Enterovirus 71 (EV71), which is the most fulminant and invasive species of enterovirus, can cause children neurologic complications and death within 2-3 days after fever and rash developed. Besides, EV71 has high sequence similarity with Coxsackie A 16 (CA16) that makes differential diagnosis difficult in clinic and laboratory. Since conventional viral diagnostic method cannot diagnose EV71 quickly and EV71 can transmit at low viral titer, the patients might delay in treatment. A quick, high sensitive, and high specific test for EV71 detection is pivotal. Electrochemical impedance spectroscopy (EIS) has been applied for detecting bio-molecules as biosensors recently. In this study, we try to build a detection platform for EV71 detection by nanogold modified EIS probe. The result shows that our probe can detect 3.6 VP1/50 μl (one EV71 particle has 60 VP1) in 3 minutes. The test can also distinguish EV71 from CA16 and lysozyme. Diagnosis of enterovirus 71 by electrochemical impedance spectroscopy has the potential to apply in clinic.

Extracellular vesicles as shuttles of tumor biomarkers and anti-tumor drugs.

PubMed

Zocco, Davide; Ferruzzi, Pietro; Cappello, Francesco; Kuo, Winston Patrick; Fais, Stefano

2014-01-01

Extracellular vesicles (EV) include vesicles released by either normal or tumor cells. EV may exceed the nanometric scale (microvesicles), or to be within the nanoscale, also called exosomes. Thus, it appears that only exosomes and larger vesicles may have the size for potential applications in nanomedicine, in either disease diagnosis or therapy. This is of particular interest for research in cancer, also because the vast majority of existing data on EV are coming from pre-clinical and clinical oncology. We know that the microenvironmental features of cancer may favor cell-to-cell paracrine communication through EV, but EV have been purified, characterized, and quantified from plasma of tumor patients as well, thus suggesting that EV may have a role in promoting and maintaining cancer dissemination and progression. These observations are prompting research efforts to evaluate the use of nanovesicles as tumor biomarkers. Moreover, EVs are emerging as natural delivery systems and in particular, exosomes may represent the ideal natural nanoshuttles for new and old anti-tumor drugs. However, much is yet to be understood about the role of EV in oncology and this article aims to discuss the future of EV in cancer on the basis of current knowledge.

Extracellular Vesicles as Shuttles of Tumor Biomarkers and Anti-Tumor Drugs

PubMed Central

Zocco, Davide; Ferruzzi, Pietro; Cappello, Francesco; Kuo, Winston Patrick; Fais, Stefano

2014-01-01

Extracellular vesicles (EV) include vesicles released by either normal or tumor cells. EV may exceed the nanometric scale (microvesicles), or to be within the nanoscale, also called exosomes. Thus, it appears that only exosomes and larger vesicles may have the size for potential applications in nanomedicine, in either disease diagnosis or therapy. This is of particular interest for research in cancer, also because the vast majority of existing data on EV are coming from pre-clinical and clinical oncology. We know that the microenvironmental features of cancer may favor cell-to-cell paracrine communication through EV, but EV have been purified, characterized, and quantified from plasma of tumor patients as well, thus suggesting that EV may have a role in promoting and maintaining cancer dissemination and progression. These observations are prompting research efforts to evaluate the use of nanovesicles as tumor biomarkers. Moreover, EVs are emerging as natural delivery systems and in particular, exosomes may represent the ideal natural nanoshuttles for new and old anti-tumor drugs. However, much is yet to be understood about the role of EV in oncology and this article aims to discuss the future of EV in cancer on the basis of current knowledge. PMID:25340037

Extracellular Vesicles in Hematological Malignancies: From Biology to Therapy

PubMed Central

Caivano, Antonella; La Rocca, Francesco; Laurenzana, Ilaria; Trino, Stefania; De Luca, Luciana; Lamorte, Daniela; Del Vecchio, Luigi; Musto, Pellegrino

2017-01-01

Extracellular vesicles (EVs) are a heterogeneous group of particles, between 15 nanometers and 10 microns in diameter, released by almost all cell types in physiological and pathological conditions, including tumors. EVs have recently emerged as particularly interesting informative vehicles, so that they could be considered a true “cell biopsy”. Indeed, EV cargo, including proteins, lipids, and nucleic acids, generally reflects the nature and status of the origin cells. In some cases, EVs are enriched of peculiar molecular cargo, thus suggesting at least a degree of specific cellular packaging. EVs are identified as important and critical players in intercellular communications in short and long distance interplays. Here, we examine the physiological role of EVs and their activity in cross-talk between bone marrow microenvironment and neoplastic cells in hematological malignancies (HMs). In these diseases, HM EVs can modify tumor and bone marrow microenvironment, making the latter “stronger” in supporting malignancy, inducing drug resistance, and suppressing the immune system. Moreover, EVs are abundant in biologic fluids and protect their molecular cargo against degradation. For these and other “natural” characteristics, EVs could be potential biomarkers in a context of HM liquid biopsy and therapeutic tools. These aspects will be also analyzed in this review. PMID:28574430

Characterization of Extracellular Vesicles by Size-Exclusion High-Performance Liquid Chromatography (HPLC).

PubMed

Huang, Tao; He, Jiang

2017-01-01

Extracellular vesicles (EVs) have recently attracted substantial attention due to the potential diagnostic and therapeutic relevance. Although a variety of techniques have been used to isolate and analyze EVs, it is still far away from satisfaction. Size-exclusion chromatography (SEC), which separates subjects by size, has been widely applied in protein purification and analysis. The purpose of this chapter is to show the applications of size-exclusion high-performance liquid chromatography (HPLC) as methods for EV characterization of impurities or contaminants of small size, and thus for quality assay for the purity of the samples of EVs.

Environmental implication of electric vehicles in China.

PubMed

Huo, Hong; Zhang, Qiang; Wang, Michael Q; Streets, David G; He, Kebin

2010-07-01

Today, electric vehicles (EVs) are being proposed in China as one of the potential options to address the dramatically increasing energy demand from on-road transport. However, the mass use of EVs could involve multiple environmental issues, because EVs use electricity that is generated primarily from coal in China. We examined the fuel-cycle CO(2), SO(2), and NO(x) emissions of EVs in China in both current (2008) and future (2030) periods and compared them with those of conventional gasoline vehicles and gasoline hybrids. EVs do not promise much benefit in reducing CO(2) emissions currently, but greater CO(2) reduction could be expected in future if coal combustion technologies improve and the share of nonfossil electricity increases significantly. EVs could increase SO(2) emissions by 3-10 times and also double NO(x) emissions compared to gasoline vehicles if charged using the current electricity grid. In the future, EVs would be able to reach the NO(x) emission level of gasoline vehicles with advanced emission control devices equipped in thermal power plants but still increase SO(2). EVs do represent an effective solution to issues in China such as oil shortage, but critical policy support is urgently needed to address the environmental issues caused by the use of EVs to make EVs competitive with other vehicle alternatives.

A novel multiplex bead-based platform highlights the diversity of extracellular vesicles

PubMed Central

Koliha, Nina; Wiencek, Yvonne; Heider, Ute; Jüngst, Christian; Kladt, Nikolay; Krauthäuser, Susanne; Johnston, Ian C. D.; Bosio, Andreas; Schauss, Astrid; Wild, Stefan

2016-01-01

The surface protein composition of extracellular vesicles (EVs) is related to the originating cell and may play a role in vesicle function. Knowledge of the protein content of individual EVs is still limited because of the technical challenges to analyse small vesicles. Here, we introduce a novel multiplex bead-based platform to investigate up to 39 different surface markers in one sample. The combination of capture antibody beads with fluorescently labelled detection antibodies allows the analysis of EVs that carry surface markers recognized by both antibodies. This new method enables an easy screening of surface markers on populations of EVs. By combining different capture and detection antibodies, additional information on relative expression levels and potential vesicle subpopulations is gained. We also established a protocol to visualize individual EVs by stimulated emission depletion (STED) microscopy. Thereby, markers on single EVs can be detected by fluorophore-conjugated antibodies. We used the multiplex platform and STED microscopy to show for the first time that NK cell–derived EVs and platelet-derived EVs are devoid of CD9 or CD81, respectively, and that EVs isolated from activated B cells comprise different EV subpopulations. We speculate that, according to our STED data, tetraspanins might not be homogenously distributed but may mostly appear as clusters on EV subpopulations. Finally, we demonstrate that EV mixtures can be separated by magnetic beads and analysed subsequently with the multiplex platform. Both the multiplex bead-based platform and STED microscopy revealed subpopulations of EVs that have been indistinguishable by most analysis tools used so far. We expect that an in-depth view on EV heterogeneity will contribute to our understanding of different EVs and functions. PMID:26901056

Update on Controls for Isolation and Quantification Methodology of Extracellular Vesicles Derived from Adipose Tissue Mesenchymal Stem Cells

PubMed Central

Franquesa, Marcella; Hoogduijn, Martin J.; Ripoll, Elia; Luk, Franka; Salih, Mahdi; Betjes, Michiel G. H.; Torras, Juan; Baan, Carla C.; Grinyó, Josep M.; Merino, Ana Maria

2014-01-01

The research field on extracellular vesicles (EV) has rapidly expanded in recent years due to the therapeutic potential of EV. Adipose tissue human mesenchymal stem cells (ASC) may be a suitable source for therapeutic EV. A major limitation in the field is the lack of standardization of the challenging techniques to isolate and characterize EV. The aim of our study was to incorporate new controls for the detection and quantification of EV derived from ASC and to analyze the applicability and limitations of the available techniques. ASC were cultured in medium supplemented with 5% of vesicles-free fetal bovine serum. The EV were isolated from conditioned medium by differential centrifugation with size filtration (0.2 μm). As a control, non-conditioned culture medium was used (control medium). To detect EV, electron microscopy, conventional flow cytometry, and western blot were used. The quantification of the EV was by total protein quantification, ExoELISA immunoassay, and Nanosight. Cytokines and growth factors in the EV samples were measured by multiplex bead array kit. The EV were detected by electron microscope. Total protein measurement was not useful to quantify EV as the control medium showed similar protein contents as the EV samples. The ExoELISA kits had technical troubles and it was not possible to quantify the concentration of exosomes in the samples. The use of Nanosight enabled quantification and size determination of the EV. It is, however, not possible to distinguish protein aggregates from EV with this method. The technologies for quantification and characterization of the EV need to be improved. In addition, we detected protein contaminants in the EV samples, which make it difficult to determine the real effect of EV in experimental models. It will be crucial in the future to optimize design novel methods for purification and characterization of EV. PMID:25374572

Inflammatory Stroke Extracellular Vesicles Induce Macrophage Activation.

PubMed

Couch, Yvonne; Akbar, Naveed; Davis, Simon; Fischer, Roman; Dickens, Alex M; Neuhaus, Ain A; Burgess, Annette I; Rothwell, Peter M; Buchan, Alastair M

2017-08-01

Extracellular vesicles (EVs) are protein-lipid complexes released from cells, as well as actively exocytosed, as part of normal physiology, but also during pathological processes such as those occurring during a stroke. Our aim was to determine the inflammatory potential of stroke EVs. EVs were quantified and analyzed in the sera of patients after an acute stroke (<24 hours; OXVASC [Oxford Vascular Study]). Isolated EV fractions were subjected to untargeted proteomic analysis by liquid chromatography mass-spectrometry/mass-spectrometry and then applied to macrophages in culture to investigate inflammatory gene expression. EV number, but not size, is significantly increased in stroke patients when compared to age-matched controls. Proteomic analysis reveals an overall increase in acute phase proteins, including C-reactive protein. EV fractions applied to monocyte-differentiated macrophage cultures induced inflammatory gene expression. Together these data show that EVs from stroke patients are proinflammatory in nature and are capable of inducing inflammation in immune cells. © 2017 American Heart Association, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Matthew A.; Redondo, Amaia Beloqui; Duyckaerts, Nicolas

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutionsmore » and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II α lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.« less

Electronic structure of Ag7GeS5I superionic compound

NASA Astrophysics Data System (ADS)

Bletskan, Dmytro; Studenyak, Ihor; Bletskan, Mykhailo; Vakulchak, Vasyl

2018-05-01

This paper presents the originally results of ab initio calculations of electronic structure, total and partial densities of electronic states as well as electronic charge density distribution of Ag7GeS5I crystal performed within the density functional theory (DFT) in the local density approximation (LDA) for exchange-correlation potential. According to performed calculations, Ag7GeS5I is the direct-gap semiconductor with the valence band top and the conductivity band bottom in the Γ point of Brillouin zone. The band gap width calculated in the LDA-approximation is Egd = 0.73 eV. The analysis of total and partial densities of electronic states allow us to identify the atomic orbital contributions into the crystal orbitals as well as the formation data of chemical bond in the studied crystal. In the top part of Ag7GeS5I valence band it was revealed the considerable mixing (hybridization) of the occupied d-states of Ag noble metal and the delocalized p-states of sulfur and iodine, which is undoubtedly associated with the covalent character of chemical bond between S, I atoms and noble metal atom.

Effect of Nitrogen Content on Physical and Chemical Properties of TiN Thin Films Prepared by DC Magnetron Sputtering with Supported Discharge

NASA Astrophysics Data System (ADS)

Kavitha, A.; Kannan, R.; Gunasekhar, K. R.; Rajashabala, S.

2017-10-01

Amorphous titanium nitride (TiN) thin films have been prepared on silicon (Si) and glass substrates by direct-current (DC) reactive magnetron sputtering with a supported discharge (triode). Nitrogen gas (N2) at partial pressure of 0.3 Pa, 0.4 Pa, 0.5 Pa, and 0.6 Pa was used to prepare the TiN thin films, maintaining total pressure of argon and N2 of about 0.7 Pa. The chemical, microstructural, optical, and electrical properties of the TiN thin films were systematically studied. Presence of different phases of Ti with nitrogen (N), oxygen (O2), and carbon (C) elements was revealed by x-ray photoelectron spectroscopy characterization. Increase in the nitrogen pressure from 0.3 Pa to 0.6 Pa reduced the optical bandgap of the TiN thin film from 2.9 eV to 2.7 eV. Photoluminescence study showed that TiN thin film deposited at N2 partial pressure of 0.3 Pa exhibited three shoulder peaks at 330 nm, 335 nm, and 340 nm, which disappeared when the sample was deposited with N2 partial pressure of 0.6 Pa. Increase in the nitrogen content decreased the electrical resistivity of the TiN thin film from 3200 μΩ cm to 1800 μΩ cm. Atomic force microscopy studies of the TiN thin films deposited with N2 partial pressure of 0.6 Pa showed a uniform surface pattern associated with accumulation of fine grains. The results and advantages of this method of preparing TiN thin films are also reported.

Extracellular vesicles are independent metabolic units with asparaginase activity

PubMed Central

Leonardi, Tommaso; Costa, Ana S. H.; Cossetti, Chiara; Peruzzotti-Jametti, Luca; Bernstock, Joshua D.; Saini, Harpreet K.; Gelati, Maurizio; Vescovi, Angelo Luigi; Bastos, Carlos; Faria, Nuno; Occhipinti, Luigi G.; Enright, Anton J.; Frezza, Christian; Pluchino, Stefano

2017-01-01

Extracellular vesicles (EVs) are membrane particles involved in the exchange of a broad range of bioactive molecules between cells and the microenvironment. While it has been shown that cells can traffic metabolic enzymes via EVs much remains to be elucidated with regard to their intrinsic metabolic activity. Accordingly, herein we assessed the ability of neural stem/progenitor cell (NSC)-derived EVs to consume and produce metabolites. Both our metabolomics and functional analyses revealed that EVs harbour L-asparaginase activity catalysed by the enzyme Asparaginase-like protein 1 (Asrgl1). Critically, we show that Asrgl1 activity is selective for asparagine and is devoid of glutaminase activity. We found that mouse and human NSC-derived EVs traffic ASRGL1. Our results demonstrate for the first time that NSC EVs function as independent, extracellular metabolic units able to modify the concentrations of critical nutrients, with the potential to affect the physiology of their microenvironment. PMID:28671681

Potential functional applications of extracellular vesicles: a report by the NIH Common Fund Extracellular RNA Communication Consortium

PubMed Central

Quesenberry, Peter J.; Aliotta, Jason; Camussi, Giovanni; Abdel-Mageed, Asim B.; Wen, Sicheng; Goldberg, Laura; Zhang, Huang-Ge; Tetta, Ciro; Franklin, Jeffrey; Coffey, Robert J.; Danielson, Kirsty; Subramanya, Vinita; Ghiran, Ionita; Das, Saumya; Chen, Clark C.; Pusic, Kae M.; Pusic, Aya D.; Chatterjee, Devasis; Kraig, Richard P.; Balaj, Leonora; Dooner, Mark

2015-01-01

The NIH Extracellular RNA Communication Program's initiative on clinical utility of extracellular RNAs and therapeutic agents and developing scalable technologies is reviewed here. Background information and details of the projects are presented. The work has focused on modulation of target cell fate by extracellular vesicles (EVs) and RNA. Work on plant-derived vesicles is of intense interest, and non-mammalian sources of vesicles may represent a very promising source for different therapeutic approaches. Retro-viral-like particles are intriguing. Clearly, EVs share pathways with the assembly machinery of several other viruses, including human endogenous retrovirals (HERVs), and this convergence may explain the observation of viral-like particles containing viral proteins and nucleic acid in EVs. Dramatic effect on regeneration of damaged bone marrow, renal, pulmonary and cardiovascular tissue is demonstrated and discussed. These studies show restoration of injured cell function and the importance of heterogeneity of different vesicle populations. The potential for neural regeneration is explored, and the capacity to promote and reverse neoplasia by EV exposure is described. The tremendous clinical potential of EVs underlies many of these projects, and the importance of regulatory issues and the necessity of general manufacturing production (GMP) studies for eventual clinical trials are emphasized. Clinical trials are already being pursued and should expand dramatically in the near future. PMID:26320942

Identification of specific antigenic epitope at N-terminal segment of enterovirus 71 (EV-71) VP1 protein and characterization of its use in recombinant form for early diagnosis of EV-71 infection.

PubMed

Zhang, Jianhua; Jiang, Bingfu; Xu, Mingjie; Dai, Xing; Purdy, Michael A; Meng, Jihong

2014-08-30

Human enterovirus 71 (EV-71) is the main etiologic agent of hand, foot and mouth disease (HFMD). We sought to identify EV-71 specific antigens and develop serologic assays for acute-phase EV-71 infection. A series of truncated proteins within the N-terminal 100 amino acids (aa) of EV-71 VP1 was expressed in Escherichia coli. Western blot (WB) analysis showed that positions around 11-21 aa contain EV-71-specific antigenic sites, whereas positions 1-5 and 51-100 contain epitopes shared with human coxsackievirus A16 (CV-A16) and human echovirus 6 (E-6). The N-terminal truncated protein of VP1, VP₁₆₋₄₃, exhibited good stability and was recognized by anti-EV-71 specific rabbit sera. Alignment analysis showed that VP₁₆₋₄₃ is highly conserved among EV-71 strains from different genotypes but was heterologous among other enteroviruses. When the GST-VP₁₆₋₄₃ fusion protein was incorporated as antibody-capture agent in a WB assay and an ELISA for detecting anti-EV-71 IgM in human sera, sensitivities of 91.7% and 77.8% were achieved, respectively, with 100% specificity for both. The characterized EV-71 VP1 protein truncated to positions 6-43 aa has potential as an antigen for detection of anti-EV-71 IgM for early diagnosis of EV-71 infection in a WB format. Copyright © 2014 Elsevier B.V. All rights reserved.

Population kinetics on K alpha lines of partially ionized Cl atoms.

PubMed

Kawamura, Tohru; Nishimura, Hiroaki; Koike, Fumihiro; Ochi, Yoshihiro; Matsui, Ryoji; Miao, Wen Yong; Okihara, Shinichiro; Sakabe, Shuji; Uschmann, Ingo; Förster, Eckhart; Mima, Kunioki

2002-07-01

A population kinetics code was developed to analyze K alpha emission from partially ionized chlorine atoms in hydrocarbon plasmas. Atomic processes are solved under collisional-radiative equilibrium for two-temperature plasmas. It is shown that the fast electrons dominantly contribute to ionize the K-shell bound electrons (i.e., inner-shell ionization) and the cold electrons to the outer-shell bound ones. Ratios of K alpha lines of partially ionized atoms are presented as a function of cold-electron temperature. The model was validated by observation of the K alpha lines from a chlorinated plastic target irradiated with 1 TW Ti:sapphire laser pulses at 1.5 x 10(17) W/cm(2), inferring a plasma temperature of about 100 eV on the target surface.

Exciplex formation in blended spin-cast films of fluorene-linked dyes and bisphthalimide quenchers.

PubMed

Stewart, David J; Dalton, Matthew J; Swiger, Rachel N; Cooper, Thomas M; Haley, Joy E; Tan, Loon-Seng

2013-05-16

Spin-cast films of dyes (donor-π-donor, donor-π-acceptor, and acceptor-π-acceptor type, where the donor is Ph2N-, the acceptor is 2-benzothiazoyl, and the π-linker is 9,9-diethylfluorene) blended with nonconjugated bisphthalimides were prepared. Upon visible-light excitation of the dyes, quenching of the excited state occurs by exciplex formation between dye and bisphthalimide molecules or, in some cases, by excimer formation or aggregation-induced emission between two dye molecules. The extent of exciplex formation is dependent on the driving force, which can be calculated using the energy difference between the lowest unoccupied molecular orbitals (LUMOs) of the dyes and bisphthalimides. The results show that complete exciplex formation occurs when this driving force is greater than 0.57 eV whereas partial exciplex formation occurs when the driving force is between 0.28 and 0.57 eV. The exciplex emission energies can also be predicted by calculating the difference between the LUMO level of the bisphthalimide and the highest occupied molecular orbital (HOMO) of the dye. These calculated values, which were obtained from the electrochemically determined energy levels, showed good agreement with the observed emission energies. The exciplex lifetimes were found to be significantly longer than the lifetimes of the lone dyes. These exciplexes formed from nonlinked donors and acceptors in the solid state might have potential uses in nonlinear photonics.

Ferritin-based nanocrystals for solar energy harvesting

NASA Astrophysics Data System (ADS)

Colton, John; Erickson, Stephen; Olsen, Cameron; Embley, Jacob; Smith, Trevor; Watt, Richard

2015-03-01

Ferritin is a 12 nm diameter hollow protein with an 8 nm cavity that can be filled with a variety of nanocrystals (ferrihydrite being native). We report on several experiments with ferritin-based nanocrystals designed to utilize ferritin for solar energy harvesting. First, we have shown that the native band gap can be altered by controlling nanocrystal size, by replacing the native iron oxide core with other metal oxides, and by depositing halides and oxo-anions with the iron oxide core. This gives available band gaps of 1.6 to 2.3 eV. Theoretical efficiency calculations based on these band gaps show that the efficiency of a multi-junction solar cell based on layered structures of ferritin can be as high as 44.9 %, and up to 63.1 % if a ferritin-based material with band gap of 1.1 eV can be developed. For the latter case, the efficiencies remain quite high even in a current-matched configuration, namely 50.0 %. We have also demonstrated that photo-excitation of these materials can produce charge separation and give rise to usable electrons; we have used photo-excited electrons to reduce gold in solution and thereby produce gold nanoparticles on the surface of the ferritin. This technique can potentially be extended to platinum, whose nanoparticles catalyze water splitting. This research was partially supported by the Utah Office of Energy Development, Governor's Energy Leadership Scholars Program.

LETTER TO THE EDITOR: Iteratively-coupled propagating exterior complex scaling method for electron hydrogen collisions

NASA Astrophysics Data System (ADS)

Bartlett, Philip L.; Stelbovics, Andris T.; Bray, Igor

2004-02-01

A newly-derived iterative coupling procedure for the propagating exterior complex scaling (PECS) method is used to efficiently calculate the electron-impact wavefunctions for atomic hydrogen. An overview of this method is given along with methods for extracting scattering cross sections. Differential scattering cross sections at 30 eV are presented for the electron-impact excitation to the n = 1, 2, 3 and 4 final states, for both PECS and convergent close coupling (CCC), which are in excellent agreement with each other and with experiment. PECS results are presented at 27.2 eV and 30 eV for symmetric and asymmetric energy-sharing triple differential cross sections, which are in excellent agreement with CCC and exterior complex scaling calculations, and with experimental data. At these intermediate energies, the efficiency of the PECS method with iterative coupling has allowed highly accurate partial-wave solutions of the full Schrödinger equation, for L les 50 and a large number of coupled angular momentum states, to be obtained with minimal computing resources.

Salivary extracellular vesicle-associated miRNAs as potential biomarkers in oral squamous cell carcinoma.

PubMed

Gai, Chiara; Camussi, Francesco; Broccoletti, Roberto; Gambino, Alessio; Cabras, Marco; Molinaro, Luca; Carossa, Stefano; Camussi, Giovanni; Arduino, Paolo G

2018-04-18

Several studies in the past have investigated the expression of micro RNAs (miRNAs) in saliva as potential biomarkers. Since miRNAs associated with extracellular vesicles (EVs) are known to be protected from enzymatic degradation, we evaluated whether salivary EVs from patients with oral squamous cell carcinoma (OSCC) were enriched with specific subsets of miRNAs. OSCC patients and controls were matched with regards to age, gender and risk factors. Total RNA was extracted from salivary EVs and the differential expression of miRNAs was evaluated by qRT-PCR array and qRT-PCR. The discrimination power of up-regulated miRNAs as biomarkers in OSCC patients versus controls was evaluated by the Receiver Operating Characteristic (ROC) curves. A preliminary qRT-PCR array was performed on samples from 5 OSCC patients and 5 healthy controls whereby a subset of miRNAs were identified that were differentially expressed. On the basis of these results, a cohort of additional 16 patients and 6 controls were analyzed to further confirm the miRNAs that were up-regulated or selectively expressed in the previous pilot study. The following miRNAs: miR-302b-3p and miR-517b-3p were expressed only in EVs from OSCC patients and miR-512-3p and miR-412-3p were up-regulated in salivary EVs from OSCC patients compared to controls with the ROC curve showing a good discrimination power for OSCC diagnosis. The Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway analysis suggested the possible involvement of the miRNAs identified in pathways activated in OSCC. In this work, we suggest that salivary EVs isolated by a simple charge-based precipitation technique can be exploited as a non-invasive source of miRNAs for OSCC diagnosis. Moreover, we have identified a subset of miRNAs selectively enriched in EVs of OSCC patients that could be potential biomarkers.

Full potential calculations on the electron bandstructures of Sphalerite, Pyrite and Chalcopyrite

NASA Astrophysics Data System (ADS)

Edelbro, R.; Sandström, Å.; Paul, J.

2003-02-01

The bulk electronic structures of Sphalerite, Pyrite and Chalcopyrite have been calculated within an ab initio, full potential, density functional approach. The exchange term was approximated with the Dirac exchange functional, the Vosko-Wilk-Nusair parameterization of the Cepler-Alder free electron gas was used for correlation and linear combinations of Gaussian type orbitals were used as basis functions. The Sphalerite (zinc blende) band gap was calculated to be direct with a width of 2.23 eV. The Sphalerite valence band was 5.2 eV wide and composed of a mixture of sulfur and zinc orbitals. The band below the valence band located around -6.2 eV was mainly composed of Zn 3d orbitals. The S 3s orbitals gave rise to a band located around -12.3 eV. Pyrite was calculated to be a semiconductor with an indirect band gap of 0.51 eV, and a direct gap of 0.55 eV. The valence band was 1.25 eV wide and mainly composed of non-bonding Fe 3d orbitals. The band below the valence band was 4.9 eV wide and composed of a mixture of sulfur and iron orbitals. Due to the short inter-atomic distance between the sulfur dumbbells, the S 3s orbitals in Pyrite were split into a bonding and an anti-bonding range. Chalcopyrite was predicted to be a conductor, with no band-crossings at the Fermi level. The bands at -13.2 eV originate from the sulfur 3s orbitals and were quite similar to the sulfur 3s bands in Sphalerite, though somewhat shifted to lower energy. The top of the valence band consisted of a mixture of orbitals from all the atoms. The lower part of the same band showed metal character. Computational modeling as a tool for illuminating the flotation and leaching processes of Pyrite and Chalcopyrite, in connection with surface science experiments, is discussed.

Electric Vehicle Ownership Factors, Preferred Safety Technologies and Commuting Behavior in the United States

DOT National Transportation Integrated Search

2017-02-01

Electric vehicles (EVs) are expected to reduce climate-changing greenhouse gas emissions, potentially reduce the ground-level ozone experienced during summers over the Mid-Atlantic's I-95 Corridor, and possibly reduce dependence on fossil fuels. EVs ...

Improving Wellbeing and Environmental Stewardship Through Volunteering in Nature.

PubMed

Molsher, Robyn; Townsend, Mardie

2016-03-01

Environmental volunteering (EV) can provide a unique way to optimise the wellbeing of participants while fostering environmental stewardship. However, the potential of EV to create human health benefits remains an under-researched area. This study provides evidence for improved wellbeing and mood state for 32 participants from diverse backgrounds undertaking EV activities. Most participants also reported improved environmental stewardship with a greatly improved understanding of the environment and the need to conserve it. Other benefits included: 31% of those seeking work obtained it; and 50% joined a volunteer group at program completion. EV provides a unique mechanism to enhance the wellbeing of the participants, while conserving the environment.

Taking advantage of the potential of mesenchymal stromal cells in liver regeneration: Cells and extracellular vesicles as therapeutic strategies

PubMed Central

Fiore, Esteban Juan; Domínguez, Luciana María; Bayo, Juan; García, Mariana Gabriela; Mazzolini, Guillermo Daniel

2018-01-01

Cell-based therapies for acute and chronic liver diseases are under continuous progress. Mesenchymal stem/stromal cells (MSCs) are multipotent cells able to migrate selectively to damaged tissue and contribute to its healing and regeneration. The MSC pro-regenerative effect occurs due to their immunomodulatory capacity and their ability to produce factors that promote cell protection and survival. Likewise, it has been observed that part of their paracrine effect is mediated by MSC-derived extracellular vesicles (EVs). EVs contain proteins, lipids and nucleic acids (DNA, mRNA, miRNA, lncRNA) from the cell of origin, allowing for intercellular communication. Recently, different studies have demonstrated that MSC-derived EVs could reproduce, at least in part, the biological effects obtained by MSC-based therapies. Moreover, due to EVs’ stability for long periods of time and easy isolation methods they have become a therapeutic option to MSCs treatments. This review summarizes the latest results achieved in clinical trials using MSCs as cell therapy for liver regeneration, the role of EVs in liver physiopathology and the potential of MSCderived EVs as intercellular mediators and therapeutic tools in liver diseases. PMID:29930465

Analysis of the synonymous codon usage bias in recently emerged enterovirus D68 strains.

PubMed

Karniychuk, Uladzimir U

2016-09-02

Understanding the codon usage pattern of a pathogen and relationship between pathogen and host's codon usage patterns has fundamental and applied interests. Enterovirus D68 (EV-D68) is an emerging pathogen with a potentially high public health significance. In the present study, the synonymous codon usage bias of 27 recently emerged, and historical EV-D68 strains was analyzed. In contrast to previously studied enteroviruses (enterovirus 71 and poliovirus), EV-D68 and human host have a high discrepancy between favored codons. Analysis of viral synonymous codon usage bias metrics, viral nucleotide/dinucleotide compositional parameters, and viral protein properties showed that mutational pressure is more involved in shaping the synonymous codon usage bias of EV-D68 than translation selection. Computation of codon adaptation indices allowed to estimate expression potential of the EV-D68 genome in several commonly used laboratory animals. This approach requires experimental validation and may provide an auxiliary tool for the rational selection of laboratory animals to model emerging viral diseases. Enterovirus D68 genome compositional and codon usage data can be useful for further pathogenesis, animal model, and vaccine design studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Electron scattering from gas phase cis-diamminedichloroplatinum(II): Quantum analysis of resonance dynamics

NASA Astrophysics Data System (ADS)

Carey, Ralph; Lucchese, Robert R.; Gianturco, F. A.

2013-05-01

We present scattering calculations of electron collisions with the platinum-containing compound cis-diamminedichloroplatinum (CDDP), commonly known as cisplatin, between 0.5 eV and 6 eV, and the corresponding isolated Pt atom from 0.1 eV to 10 eV. We find evidence of resonances in e--CDDP scattering, using an ab initio description of the target. We computed scattering matrix elements from equations incorporating exchange and polarization effects through the use of the static-exchange plus density functional correlation potential. Additionally, we made use of a purely local adiabatic model potential that allows Siegert eigenstates to be calculated, thereby allowing inspection of the possible resonant scattering wave functions. The total cross section for electron scattering from (5d10) 1S Pt displays a large magnitude, monotonic decay from the initial collision energies, with no apparent resonance scattering features in any scattering symmetry. By contrast, the e--CDDP scattering cross section shows a small feature near 3.8 eV, which results from a narrow, well localized resonance of b2 symmetry. These findings are then related to the possible electron-mediated mechanism of the action of CDDP on DNA replication as suggested by recent experiments.

First-principles investigation of CO adsorption on pristine, C-doped and N-vacancy defected hexagonal AlN nanosheets

NASA Astrophysics Data System (ADS)

Ouyang, Tianhong; Qian, Zhao; Ahuja, Rajeev; Liu, Xiangfa

2018-05-01

The optimized atomic structures, energetics and electronic structures of toxic gas CO adsorption systems on pristine, C-doped and N-vacancy defected h-AlN nanosheets respectively have been investigated using Density functional theory (DFT-D2 method) to explore their potential gas detection or sensing capabilities. It is found that both the C-doping and the N-vacancy defect improve the CO adsorption energies of AlN nanosheet (from pure -3.847 eV to -5.192 eV and -4.959 eV). The absolute value of the system band gap change induced by adsorption of CO can be scaled up to 2.558 eV or 1.296 eV after C-doping or N-vacancy design respectively, which is evidently larger than the value of 0.350 eV for pristine material and will benefit the robustness of electronic signals in potential gas detection. Charge transfer mechanisms between CO and the AlN nanosheet have been presented by the Bader charge and differential charge density analysis to explore the deep origin of the underlying electronic structure changes. This theoretical study is proposed to predict and understand the CO adsorption properties of the pristine and defected h-AlN nanosheets and would help to guide experimentalists to develop better AlN-based two-dimensional materials for efficient gas detection or sensing applications in the future.

Functional transferred DNA within extracellular vesicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Jin; Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province; Wu, Gengze

Extracellular vesicles (EVs) are small membrane vesicles including exosomes and shedding vesicles that mediated a cell-to-cell communication. EVs are released from almost all cell types under both physiological and pathological conditions and incorporate nuclear and cytoplasmic molecules for intercellular delivery. Besides protein, mRNA, and microRNA of these molecules, as recent studies show, specific DNA are prominently packaged into EVs. It appears likely that some of exosomes or shedding vesicles, bearing nuclear molecules are released upon bubble-like blebs. Specific interaction of EVs with susceptible recipients performs the uptake of EVs into the target cells, discharging their cargo including nuclear and cytoplasmicmore » macromolecules into the cytosol. These findings expand the nucleic acid content of EVs to include increased levels of specific DNA. Thus, EVs contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer and atherosclerosis. In this review, the focus is on the characteristics, biological functions, and roles in diseases of DNA within EVs. - Highlights: • This review is focused on the DNA within EVs including its characteristics, biological functions, and roles in diseases. • It is clear that DNA within EVs might have important physiological and pathological roles in various diseases. • Knowledge in this area may provides us alternative methods for disease diagnosis or therapy in the future.« less

Development of a magnetic bead-based method for the collection of circulating extracellular vesicles.

PubMed

Shih, Chun-Liang; Chong, Kowit-Yu; Hsu, Shih-Che; Chien, Hsin-Jung; Ma, Ching-Ting; Chang, John Wen-Cheng; Yu, Chia-Jung; Chiou, Chiuan-Chian

2016-01-25

Cells release different types of extracellular vesicles (EVs). These EVs contain biomolecules, including proteins and nucleic acids, from their parent cells, which can be useful for diagnostic applications. The aim of this study was to develop a convenient procedure to collect circulating EVs with detectable mRNA or other biomolecules. Magnetic beads coated with annexin A5 (ANX-beads), which bound to phosphatidylserine moieties on the surfaces of most EVs, were tested for their ability to capture induced apoptotic bodies in vitro and other phosphatidylserine-presenting vesicles in body fluids. Our results show that up to 60% of induced apoptotic bodies could be captured by the ANX-beads. The vesicles captured from cultured media or plasma contained amplifiable RNA. Suitable blood samples for EV collection included EDTA-plasma and serum but not heparin-plasma. In addition, EVs in plasma were labile to freeze-and-thaw cycles. In rodents xenografted with human cancer cells, tumor-derived mRNA could be detected in EVs captured from serum samples. Active proteins could be detected in EVs captured from ascites but not from plasma. In conclusion, we have developed a magnetic bead-based procedure for the collection of EVs from body fluids and proved that captured EVs contain biomolecules from their parent cells, and therefore have great potential for disease diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification of a Novel Enterovirus Species in Rhesus Macaque in China.

PubMed

Ao, Yuan-Yun; Yu, Jie-Mei; Zhang, Cui-Yuan; Xin, Yun-Yun; Li, Li-Li; Duan, Zhao-Jun

2016-06-22

Recent studies of Enterovirus (EV) in nonhuman primates (NHPs), which could act as a source of future emerging human viral diseases, have boosted interest in the search for novel EVs. Here, a highly divergent strain of EV, tentatively named SEV-gx, was identified by viral metagenomic analysis from stool samples of rhesus macaques in China. In total, 27 of 280 (9.6%) faecal samples from rhesus macaques were positive for SEV-gx. Its complete genomic sequence is 7,367 nucleotide (nt). Genomic analyses showed that it has a standard genomic organisation for EVs, being more closely related to EV-J strains (approximately 54.0%, 43.0-44.1%, 52.3-55.2%, 61.1-62.7% and 64.0% amino acids identity in polyprotein, P1, P2 and P3 and combined 2C/3CD regions, respectively). It was also shown to have genome characteristics typical of EVs. Phylogenetic analysis of P1, 2C and 3CD aa indicated that SEV-gx can be classified as a distinct cluster in the EVs. All of this evidence demonstrates SEV-gx is a novel species (tentatively named EV-K) in the EV genus, which contributes to our understanding of the genetic diversity and evolution of EVs. Further studies are needed to investigate the potential pathogenicity of SEV-gx in NHPs and humans.

An ab initio study on MgX 3- and CaX 3- superhalogen anions (X=F, Cl, Br)

NASA Astrophysics Data System (ADS)

Anusiewicz, Iwona; Sobczyk, Monika; Dąbkowska, Iwona; Skurski, Piotr

2003-06-01

The vertical electron detachment energies (VDEs) of twenty MX 3- (M=Mg, Ca; X=F, Cl, Br) anions were calculated at the OVGF level with the 6-311++G(3df) basis sets. The largest vertical electron binding energy was found for MgF 3- system (8.793 eV). All negatively charged species possess the VDEs that are larger than 5.9 eV and thus may be termed superhalogen anions. The strong dependence of the VDE of the MX 3- species on the ligand-central atom (M-X) distance and on the partial atomic charge localized on Mg or Ca was observed and discussed, as well as the other factors that may influence the electronic stability of such anions.

Pathogenic or Therapeutic Extracellular Vesicles in Rheumatic Diseases: Role of Mesenchymal Stem Cell-Derived Vesicles

PubMed Central

Cosenza, Stella; Ruiz, Maxime; Maumus, Marie; Jorgensen, Christian; Noël, Danièle

2017-01-01

Extracellular vesicles (EVs) are important mediators of cell-to-cell communication pathways via the transport of proteins, mRNA, miRNA and lipids. There are three main types of EVs, exosomes, microparticles and apoptotic bodies, which are classified according to their size and biogenesis. EVs are secreted by all cell types and their function reproduces that of the parental cell. They are involved in many biological processes that regulate tissue homeostasis and physiopathology of diseases. In rheumatic diseases, namely osteoarthritis (OA) and rheumatoid arthritis (RA), EVs have been isolated from synovial fluid and shown to play pathogenic roles contributing to progression of both diseases. By contrast, EVs may have therapeutic effect via the delivery of molecules that may stop disease evolution. In particular, EVs derived from mesenchymal stem cells (MSCs) reproduce the main functions of the parental cells and therefore represent the ideal type of EVs for modulating the course of either disease. The aim of this review is to discuss the role of EVs in OA and RA focusing on their potential pathogenic effect and possible therapeutic options. Special attention is given to MSCs and MSC-derived EVs for modulating OA and RA progression with the perspective of developing innovative therapeutic strategies. PMID:28441721

Optical-model potential for electron and positron elastic scattering by atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salvat, Francesc

2003-07-01

An optical-model potential for systematic calculations of elastic scattering of electrons and positrons by atoms and positive ions is proposed. The electrostatic interaction is determined from the Dirac-Hartree-Fock self-consistent atomic electron density. In the case of electron projectiles, the exchange interaction is described by means of the local-approximation of Furness and McCarthy. The correlation-polarization potential is obtained by combining the correlation potential derived from the local density approximation with a long-range polarization interaction, which is represented by means of a Buckingham potential with an empirical energy-dependent cutoff parameter. The absorption potential is obtained from the local-density approximation, using the Born-Ochkurmore » approximation and the Lindhard dielectric function to describe the binary collisions with a free-electron gas. The strength of the absorption potential is adjusted by means of an empirical parameter, which has been determined by fitting available absolute elastic differential cross-section data for noble gases and mercury. The Dirac partial-wave analysis with this optical-model potential provides a realistic description of elastic scattering of electrons and positrons with energies in the range from {approx}100 eV up to {approx}5 keV. At higher energies, correlation-polarization and absorption corrections are small and the usual static-exchange approximation is sufficiently accurate for most practical purposes.« less

Extracellular vesicle long noncoding RNA as potential biomarkers of liver cancer

PubMed Central

Mohankumar, Swathi

2016-01-01

Analysis of extracellular vesicles (EV) and their contents may be useful as disease biomarkers if they reflect the contents of cells of origin, differ between normal and diseased tissue and can be reliably detected. An increasing number of long noncoding RNA (lncRNA) are being reported to be aberrantly expressed in human cancers. These tumor-associated lncRNA may have potential as new biomarkers of disease. In this review, we highlight lncRNAs that are commonly associated with hepatocellular cancer, and summarize their potential biological roles and underlying molecular mechanisms. While lncRNA can be detected in the circulation, their low expression within circulating vesicles will require the use of highly sensitive detection technologies such as digital polymerase chain reaction or next-generation sequencing. While the integrity and functional role of tumor-specific lncRNAs within EV have yet to be established, their presence or enrichment within tumor cell-derived EV offers promise for their potential as disease biomarkers. PMID:26634812

Nanotechnology for environmentally sustainable electromobility

NASA Astrophysics Data System (ADS)

Ellingsen, Linda Ager-Wick; Hung, Christine Roxanne; Majeau-Bettez, Guillaume; Singh, Bhawna; Chen, Zhongwei; Whittingham, M. Stanley; Strømman, Anders Hammer

2016-12-01

Electric vehicles (EVs) powered by lithium-ion batteries (LIBs) or proton exchange membrane hydrogen fuel cells (PEMFCs) offer important potential climate change mitigation effects when combined with clean energy sources. The development of novel nanomaterials may bring about the next wave of technical improvements for LIBs and PEMFCs. If the next generation of EVs is to lead to not only reduced emissions during use but also environmentally sustainable production chains, the research on nanomaterials for LIBs and PEMFCs should be guided by a life-cycle perspective. In this Analysis, we describe an environmental life-cycle screening framework tailored to assess nanomaterials for electromobility. By applying this framework, we offer an early evaluation of the most promising nanomaterials for LIBs and PEMFCs and their potential contributions to the environmental sustainability of EV life cycles. Potential environmental trade-offs and gaps in nanomaterials research are identified to provide guidance for future nanomaterial developments for electromobility.

Focus on Extracellular Vesicles: Physiological Role and Signalling Properties of Extracellular Membrane Vesicles

PubMed Central

Iraci, Nunzio; Leonardi, Tommaso; Gessler, Florian; Vega, Beatriz; Pluchino, Stefano

2016-01-01

Extracellular vesicles (EVs) are a heterogeneous population of secreted membrane vesicles, with distinct biogenesis routes, biophysical properties and different functions both in physiological conditions and in disease. The release of EVs is a widespread biological process, which is conserved across species. In recent years, numerous studies have demonstrated that several bioactive molecules are trafficked with(in) EVs, such as microRNAs, mRNAs, proteins and lipids. The understanding of their final impact on the biology of specific target cells remains matter of intense debate in the field. Also, EVs have attracted great interest as potential novel cell-free therapeutics. Here we describe the proposed physiological and pathological functions of EVs, with a particular focus on their molecular content. Also, we discuss the advances in the knowledge of the mechanisms regulating the secretion of EV-associated molecules and the specific pathways activated upon interaction with the target cell, highlighting the role of EVs in the context of the immune system and as mediators of the intercellular signalling in the brain. PMID:26861302

Correlation effects in elastic e-N2 scattering

NASA Technical Reports Server (NTRS)

Huo, Winifred M.; Lima, Marco A. P.; Gibson, Thomas L.; Mckoy, Vincent

1987-01-01

The Schwinger multichannel formulation has been applied to study the role of electron correlation in low-energy e-N2 scattering. For the five nonresonant partial-wave channels studied here, angular correlation is found to be much more important than radial correlation. The calculated total and differential cross sections agree well with experiment except for the differential cross sections at 1.5 eV.

An Experimental and Theoretical Study on Cavitating Propellers.

DTIC Science & Technology

1982-10-01

34 And Identfyp eV &to" nMeeJ cascade flow theoretical supercavitating flow performance prediction method partially cavitating flow supercavitating ...the present work was to develop an analytical tool for predicting the off-design performance of supercavitating propellers over a wide range of...operating conditions. Due to the complex nature of the flow phenomena, a lifting line theory sirply combined with the two-dimensional supercavitating

Photoluminescence and positron annihilation spectroscopic investigation on a H+ irradiated ZnO single crystal

NASA Astrophysics Data System (ADS)

Sarkar, A.; Chakrabarti, Mahuya; Sanyal, D.; Bhowmick, D.; Dechoudhury, S.; Chakrabarti, A.; Rakshit, Tamita; Ray, S. K.

2012-08-01

Low temperature photoluminescence and room temperature positron annihilation spectroscopy have been employed to investigate the defects incorporated by 6 MeV H+ ions in a hydrothermally grown ZnO single crystal. Prior to irradiation, the emission from donor bound excitons is at 3.378 eV (10 K). The irradiation creates an intense and narrow emission at 3.368 eV (10 K). The intensity of this peak is nearly four times that of the dominant near band edge peak of the pristine crystal. The characteristic features of the 3.368 eV emission indicate its origin as a ‘hydrogen at oxygen vacancy’ type defect. The positron annihilation lifetime measurement reveals a single component lifetime spectrum for both the unirradiated (164 ± 1 ps) and irradiated crystal (175 ± 1 ps). It reflects the fact that the positron lifetime and intensity of the new irradiation driven defect species are a little higher compared to those in the unirradiated crystal. However, the estimated defect concentration, even considering the high dynamic defect annihilation rate in ZnO, comes out to be ˜4 × 1017 cm-3 (using SRIM software). This is a very high defect concentration compared to the defect sensitivity of positron annihilation spectroscopy. A probable reason is the partial filling of the incorporated vacancies (positron traps), which in ZnO are zinc vacancies. The positron lifetime of ˜175 ps (in irradiated ZnO) is consistent with recent theoretical calculations for partially hydrogen-filled zinc vacancies in ZnO. Passivation of oxygen vacancies by hydrogen is also reflected in the photoluminescence results. A possible reason for such vacancy filling (at both Zn and O sites) due to irradiation has also been discussed.

Changes in enterovirus serotype constituent ratios altered the clinical features of infected children in Guangdong Province, China, from 2010 to 2013.

PubMed

Zhou, Hong-Tao; Guo, Yong-Hui; Chen, Man-Jun; Pan, Yu-Xian; Xue, Lin; Wang, Bin; Tao, Shao-Hua; Yu, Nan

2016-08-09

Enterovirus (EV)-related hand, foot, and mouth disease/herpangina (HFMD/HA) has been prevalent in Guangdong Province, China, since 2010. Clinical data for EV-related HFMD/HA inpatients admitted to the Department of Paediatrics of Zhujiang Hospital from 2010 to 2013 were retrospectively reviewed. The corresponding EV serotypes were also determined by reverse transcription-polymerase chain reaction or BLAST analysis of the sequenced partial lengths of the viral protein1/5'-untranslated region. A total of 867 eligible inpatients admitted during 2010-2013 were included in the study. Of these, the serotype of the responsible EV was successfully identified in 824 cases. The incidence of enterovirus 71 (EV71) infection amongst pediatric HFMD/HA inpatients decreased dramatically from 55.5 % in 2010 to 8.1 % in 2013, with a similar decrease recorded for coxsackievirus A16 (CVA16). However, the incidence of non-EV71/CVA16 infection increased from 30.0 % in 2010 to 83.8 % in 2013. We noted that the types of infection caused by different EV serotypes varied: EV71 was responsible for 100 % of the paralysis cases (26/26), 84.6 % of the deaths (11/13), and 84.1 % of cases with severe central nervous system involvement (SCNSI) (74/88); echovirus contributed to 16.4 % of the deaths (2/13) and 4.4 % of the SCNSI cases; and coxsackievirus accounted for only 2.2 % of the SCNSI cases (2/90). The clinical features of HFMD/HA cases varied greatly during the time period examined, with drastic changes in the hospitalization rates (45.1, 63.7, 36.4, and 19.1 % for 2010, 2011, 2012, and 21013, respectively), mortality rates (2.3, 0.9, 2.5, and 0.0 %, respectively), paralysis (5.1, 1.2, 5.4, and 0.0 %, respectively), SCNSI (16.8, 7.1, 12.7, and 2.2 %, respectively), and acute respiratory infection (21.1, 22.0, 45.9, and 59.0 %, respectively). The incidences of infection caused by different EV serotypes, along with the clinical features of HFMD/HA cases, changed drastically in Guangdong Province, China, from 2010 to 2013, with the biggest changes observed in 2013. The changed constituent ratios of the different EV serotypes might therefore be responsible for the differences in the observed clinical features of HFMD/HA during this period.

Calculating Rayleigh scattering amplitudes from 100 eV to 10 MeV. [100 eV to 10 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, J.C.; Reynaud, G.W.; Botto, D.J.

1979-05-01

An attempt is made to explain how to calculate the contribution to elastic photon-atom scattering due to Rayleigh scattering (the scattering off bound electrons) in the photon energy range 100 eV less than or equal to W less than or equal to 10 MeV. All intermediate calculations are described, including the calculation of the potential, bound state wave functions, matrix elements, and final cross sections. 12 references. (JFP)

Ab initio molecular dynamics simulations of AlN responding to low energy particle radiation

DOE PAGES

Xi, Jianqi; Liu, Bin; Zhang, Yanwen; ...

2018-01-30

Ab initio molecular dynamics simulations of low energy recoil events in wurtzite AlN have been performed to determine threshold displacement energies, defect production and evolution mechanisms, role of partial charge transfer during the process, and the influence of irradiation-induced defects on the properties of AlN. Here, the results show that the threshold displacement energies, E d, along the direction parallel to the basal planes are smaller than those perpendicular to the basal planes. The minimum E d values are determined to be 19 eV and 55 eV for N and Al atom, respectively, which occur along the [more » $$\\overline{11}20$$] direction. In general, the threshold displacement energies for N are smaller than those for Al atom, indicating the N defects would be dominant under irradiation. The defect production mechanisms have been analyzed. It is found that charge transfer and redistribution for both the primary knock-on atom and the subsequent recoil atoms play a significant role in defect production and evolution. Similar to the trend in oxide materials, there is a nearly linear relationship between E d and the total amount of charge transfer at the potential energy peak in AlN, which provides guidance on the development of charge-transfer interatomic potentials for classic molecular dynamics simulations. Finally, the response behavior of AlN to low energy irradiation is qualitatively investigated. The existence of irradiation-induced defects significantly modifies the electronic structure, and thus affects the magnetic, electronic and optical properties of AlN. In conclusion, these findings further enrich the understanding of defects in the wide bandgap semiconductor of AlN.« less

Ab initio molecular dynamics simulations of AlN responding to low energy particle radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xi, Jianqi; Liu, Bin; Zhang, Yanwen

Ab initio molecular dynamics simulations of low energy recoil events in wurtzite AlN have been performed to determine threshold displacement energies, defect production and evolution mechanisms, role of partial charge transfer during the process, and the influence of irradiation-induced defects on the properties of AlN. Here, the results show that the threshold displacement energies, E d, along the direction parallel to the basal planes are smaller than those perpendicular to the basal planes. The minimum E d values are determined to be 19 eV and 55 eV for N and Al atom, respectively, which occur along the [more » $$\\overline{11}20$$] direction. In general, the threshold displacement energies for N are smaller than those for Al atom, indicating the N defects would be dominant under irradiation. The defect production mechanisms have been analyzed. It is found that charge transfer and redistribution for both the primary knock-on atom and the subsequent recoil atoms play a significant role in defect production and evolution. Similar to the trend in oxide materials, there is a nearly linear relationship between E d and the total amount of charge transfer at the potential energy peak in AlN, which provides guidance on the development of charge-transfer interatomic potentials for classic molecular dynamics simulations. Finally, the response behavior of AlN to low energy irradiation is qualitatively investigated. The existence of irradiation-induced defects significantly modifies the electronic structure, and thus affects the magnetic, electronic and optical properties of AlN. In conclusion, these findings further enrich the understanding of defects in the wide bandgap semiconductor of AlN.« less

First-principles study of structural, electronic, linear and nonlinear optical properties of Ga{2}PSb ternary chalcopyrite

NASA Astrophysics Data System (ADS)

Ouahrani, T.; Reshak, A. H.; de La Roza, A. Otero; Mebrouki, M.; Luaña, V.; Khenata, R.; Amrani, B.

2009-12-01

We report results from first-principles density functional calculations using the full-potential linear augmented plane wave (FP-LAPW) method. The generalized gradient approximation (GGA) and the Engel-Vosko-generalized gradient approximation (EV-GGA) were used for the exchange-correlation energy of the structural, electronic, linear and nonlinear optical properties of the chalcopyrite Ga2PSb compound. The valence band maximum (VBM) is located at the Γv point, and the conduction band minimum (CBM) is located at the Γc point, resulting in a direct band gap of about 0.365 eV for GGA and 0.83 eV for EV-GGA. In comparison with the experimental one (1.2 eV) we found that EV-GGA calculation gives energy gap in reasonable agreement with the experiment. The spin orbit coupling has marginal influence on the optical properties. The ground state quantities such as lattice parameters (a, c and u), bulk modules B and its pressure derivative B^primeare evaluated.

Spitting out the demons: Extracellular vesicles in glioblastoma.

PubMed

André-Grégoire, Gwennan; Gavard, Julie

2017-03-04

Discovered decades ago, extracellular vesicles (EVs) emerge as dedicated organelles, able to deliver protected, specific cellular cues throughout the organism. While virtually every cell can release EVs, cancer cells co-opted this feature and efficiently unleashed them both in the tumor microenvironment and toward healthy tissues. This might contribute to tumor aggressiveness and spreading. Cancer-derived EVs that contain DNA, mRNA, miRNA, and packed and transmembrane proteins can operate locally or at distance. This review will focus on the high-grade brain tumor (i.e. glioblastoma)-derived EVs, discussing recent reports on i) their phenotype and content, ii) their putative functions, and iii) their clinical potential for improving diagnosis and therapeutics.

Exacerbation of Acute Traumatic Brain Injury by Circulating Extracellular Vesicles.

PubMed

Hazelton, Isla; Yates, Abi; Dale, Ashley; Roodselaar, Jay; Akbar, Naveed; Ruitenberg, Marc J; Anthony, Daniel C; Couch, Yvonne

2018-02-15

Inflammatory lesions in the brain activate a systemic acute-phase response (APR), which is dependent on the release of extracellular vesicles (EVs) into the circulation. The resulting APR is responsible for regulating leukocyte mobilization and subsequent recruitment to the brain. Factors that either exacerbate or inhibit the APR will also exacerbate or inhibit central nervous system (CNS) inflammation as a consequence and have the potential to influence ongoing secondary damage. Here, we were interested to discover how the circulating EV population changes after traumatic brain injury (TBI) and how manipulation of the circulating EV pool impacts on the outcome of TBI. We found the number of circulating EVs increased rapidly post-TBI, and this was accompanied by an increase in CNS and hepatic leukocyte recruitment. In an adoptive transfer study, we then evaluated the outcomes of TBI after administering EVs derived from either in vitro macrophage or endothelial cell lines stimulated with lipopolysaccharide (LPS), or from murine plasma from an LPS challenge using the air-pouch model. By manipulating the circulating EV population, we were able to demonstrate that each population of transferred EVs increased the APR. However, the characteristics of the response were dependent on the nature of the EVs; specifically, it was significantly increased when animals were challenged with macrophage-derived EVs, suggesting that the cellular origins of EVs may determine their function. Selectively targeting EVs from macrophage/monocyte populations is likely to be of value in reducing the impact of the systemic inflammatory response on the outcome of traumatic CNS injury.

InterEvDock2: an expanded server for protein docking using evolutionary and biological information from homology models and multimeric inputs.

PubMed

Quignot, Chloé; Rey, Julien; Yu, Jinchao; Tufféry, Pierre; Guerois, Raphaël; Andreani, Jessica

2018-05-08

Computational protein docking is a powerful strategy to predict structures of protein-protein interactions and provides crucial insights for the functional characterization of macromolecular cross-talks. We previously developed InterEvDock, a server for ab initio protein docking based on rigid-body sampling followed by consensus scoring using physics-based and statistical potentials, including the InterEvScore function specifically developed to incorporate co-evolutionary information in docking. InterEvDock2 is a major evolution of InterEvDock which allows users to submit input sequences - not only structures - and multimeric inputs and to specify constraints for the pairwise docking process based on previous knowledge about the interaction. For this purpose, we added modules in InterEvDock2 for automatic template search and comparative modeling of the input proteins. The InterEvDock2 pipeline was benchmarked on 812 complexes for which unbound homology models of the two partners and co-evolutionary information are available in the PPI4DOCK database. InterEvDock2 identified a correct model among the top 10 consensus in 29% of these cases (compared to 15-24% for individual scoring functions) and at least one correct interface residue among 10 predicted in 91% of these cases. InterEvDock2 is thus a unique protein docking server, designed to be useful for the experimental biology community. The InterEvDock2 web interface is available at http://bioserv.rpbs.univ-paris-diderot.fr/services/InterEvDock2/.

Peptidyl aldehyde NK-1.8k suppresses enterovirus 71 and enterovirus 68 infection by targeting protease 3C.

PubMed

Wang, Yaxin; Yang, Ben; Zhai, Yangyang; Yin, Zheng; Sun, Yuna; Rao, Zihe

2015-05-01

Enterovirus (EV) is one of the major causative agents of hand, foot, and mouth disease in the Pacific-Asia region. In particular, EV71 causes severe central nervous system infections, and the fatality rates from EV71 infection are high. Moreover, an outbreak of respiratory illnesses caused by an emerging EV, EV68, recently occurred among over 1,000 young children in the United States and was also associated with neurological infections. Although enterovirus has emerged as a considerable global public health threat, no antiviral drug for clinical use is available. In the present work, we screened our compound library for agents targeting viral protease and identified a peptidyl aldehyde, NK-1.8k, that inhibits the proliferation of different EV71 strains and one EV68 strain and that had a 50% effective concentration of 90 nM. Low cytotoxicity (50% cytotoxic concentration, >200 μM) indicated a high selective index of over 2,000. We further characterized a single amino acid substitution inside protease 3C (3C(pro)), N69S, which conferred EV71 resistance to NK-1.8k, possibly by increasing the flexibility of the substrate binding pocket of 3C(pro). The combination of NK-1.8k and an EV71 RNA-dependent RNA polymerase inhibitor or entry inhibitor exhibited a strong synergistic anti-EV71 effect. Our findings suggest that NK-1.8k could potentially be developed for anti-EV therapy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Ionizing and Non-ionizing Radiation Effects in Thin Layer Hexagonal Boron Nitride

DTIC Science & Technology

2015-03-01

capacitance-voltage measurements indicating Frenkel-Poole (FP) and Fowler-Nordheim tunneling (FNT) are the primary current mechanisms before and after...linear FNT model and a 0.013 eV increase in the barrier potential for the FP model. There was a decrease of 0.19 eV in the tunneling potential for the...non-linear FNT model. Defects generated by the neutron damage increased currents by increasing trap assisted tunneling (TAT). v

Clinically isolated enterovirus A71 subgenogroup C4 strain with lethal pathogenicity in 14-day-old mice and the application as an EV-A71 mouse infection model.

PubMed

Xu, Yi; Ma, Shuzhi; Zhu, Limeng; Huang, Zhiqiu; Chen, Liyun; Xu, Yuhua; Yin, Haibin; Peng, Tao; Wang, Yi

2017-01-01

The Enterovirus A71 (EV-A71) subgenogroup C4 is prevalent in China. EV-A71 causes hand, foot and mouth disease (HFMD) in children and may lead to severe neurological diseases. The development of antiviral and protective vaccines against EV-A71 is significantly hindered by the lack of suitable animal models to recapitulate human neurological symptoms. In this study, GZ-CII, a highly virulent EV-A71 subgenogroup C4 strain, was isolated from hospitalized children with HFMD. Intraperitoneal infections of GZ-CII resulted in progressive neurological disease in mice as old as 14 days. Administration of an inactivated EV-A71 vaccine or an anti-EV-A71 immune serum protected the mice against the GZ-CII infection. This demonstrated that a mouse model with EV-A71 GZ-CII could be used to evaluate potential vaccine candidates and therapeutics for subgenogroup C4. Comparing the genome sequence of GZ-CII with that of the avirulent EV-A71 subgenogroup C4 strain revealed unique mutations in GZ-CII. When mutation VP2-K149I was introduced into the nonpathogenic EV-A71 subgenogroup C4 strain, the variant similar to GZ-CII significantly increased viral replication and virulence in mice. These results indicated that the VP2-K149I mutation played an important role in enhancing the virulence of the EV-A71 subgenogroup C4 strain in mice, and that mice infected with the GZ-CII strain are a promising model for evaluating vaccines and therapeutics against the EV-A71 subgenogroup C4. Copyright © 2016 Elsevier B.V. All rights reserved.

Human Enterovirus 68 Interferes with the Host Cell Cycle to Facilitate Viral Production

PubMed Central

Wang, Zeng-yan; Zhong, Ting; Wang, Yue; Song, Feng-mei; Yu, Xiao-feng; Xing, Li-ping; Zhang, Wen-yan; Yu, Jing-hua; Hua, Shu-cheng; Yu, Xiao-fang

2017-01-01

Enterovirus D68 (EV-D68) is an emerging pathogen that recently caused a large outbreak of severe respiratory disease in the United States and other countries. Little is known about the relationship between EV-D68 virus and host cells. In this study, we assessed the effect of the host cell cycle on EV-D68 viral production, as well as the ability of EV-D68 to manipulate host cell cycle progression. The results suggest that synchronization in G0/G1 phase, but not S phase, promotes viral production, while synchronization in G2/M inhibits viral production. Both an early EV-D68 isolate and currently circulating strains of EV-D68 can manipulate the host cell cycle to arrest cells in the G0/G1 phase, thus providing favorable conditions for virus production. Cell cycle regulation by EV-D68 was associated with corresponding effects on the expression of cyclins and CDKs, which were observed at the level of the protein and/or mRNA. Furthermore, the viral non-structural protein 3D of EV-D68 prevents progression from G0/G1 to S. Interestingly, another member of the Picornaviridae family, EV-A71, differs from EV-D68 in that G0/G1 synchronization inhibits, rather than promotes, EV-A71 viral replication. However, these viruses are similar in that G2/M synchronization inhibits the production and activity of both viruses, which is suggestive of a common therapeutic target for both types of enterovirus. These results further clarify the pathogenic mechanisms of enteroviruses and provide a potential strategy for the treatment and prevention of EV-D68-related disease. PMID:28229049

Biological reference materials for extracellular vesicle studies.

PubMed

Valkonen, S; van der Pol, E; Böing, A; Yuana, Y; Yliperttula, M; Nieuwland, R; Laitinen, S; Siljander, P R M

2017-02-15

Extracellular vesicles (EVs) mediate normal physiological homeostasis and pathological processes by facilitating intercellular communication. Research of EVs in basic science and clinical settings requires both methodological standardization and development of reference materials (RM). Here, we show insights and results of biological RM development for EV studies. We used a three-step approach to find and develop a biological RM. First, a literature search was done to find candidates for biological RMs. Second, a questionnaire was sent to EV researchers querying the preferences for RM and their use. Third, a biological RM was selected, developed, characterized, and evaluated. The responses to the survey demonstrated a clear and recognized need for RM optimized for the calibration of EV measurements. Based on the literature, naturally occurring and produced biological RM, such as virus particles and liposomes, were proposed as RM. However, none of these candidate RMs have properties completely matching those of EVs, such as size and refractive index distribution. Therefore, we evaluated the use of nanoerythrosomes (NanoE), vesicles produced from erythrocytes, as a potential biological RM. The strength of NanoE is their resemblance to EVs. Compared to the erythrocyte-derived EVs (eryEVs), NanoE have similar morphology, a similar refractive index (1.37), larger diameter (70% of the NanoE are over 200nm), and increased positive staining for CD235a and lipids (Di-8-ANEPPS) (58% and 67% in NanoE vs. 21% and 45% in eryEVs, respectively). Altogether, our results highlight the general need to develop and validate new RM with similar physical and biochemical properties as EVs to standardize EV measurements between instruments and laboratories. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Development of a sensitive and specific epitope-blocking ELISA for universal detection of antibodies to human enterovirus 71 strains.

PubMed

He, Fang; Kiener, Tanja K; Lim, Xiao Fang; Tan, Yunrui; Raj, Kattur Venkatachalam Ashok; Tang, Manli; Chow, Vincent T K; Chen, Qingfeng; Kwang, Jimmy

2013-01-01

Human Enterovirus 71 (EV71) is a common cause of hand, foot and mouth disease (HFMD) in young children. It is often associated with severe neurological diseases and mortalities in recent outbreaks across the Asia Pacific region. Currently, there is no efficient universal antibody test available to detect EV71 infections. In the present study, an epitope-blocking ELISA was developed to detect specific antibodies to human EV71 viruses in human or animal sera. The assay relies on a novel monoclonal antibody (Mab 1C6) that specifically binds to capsid proteins in whole EV71 viruses without any cross reaction to any EV71 capsid protein expressed alone. The sensitivity and specificity of the epitope-blocking ELISA for EV71 was evaluated and compared to microneutralization using immunized animal sera to multiple virus genotypes of EV71 and coxsackieviruses. Further, 200 serum sample from human individuals who were potentially infected with EV71 viruses were tested in both the blocking ELISA and microneutralization. Results indicated that antibodies to EV71 were readily detected in immunized animals or human sera by the epitope blocking ELISA whereas specimens with antibodies to other enteroviruses yielded negative results. This assay is not only simpler to perform but also shows higher sensitivity and specificity as compared to microneutralization. The epitope-blocking ELISA based on a unique Mab 1C6 provided highly sensitive and 100% specific detection of antibodies to human EV71 viruses in human sera.

How to Assess the External Validity and Model Validity of Therapeutic Trials: A Conceptual Approach to Systematic Review Methodology

PubMed Central

2014-01-01

Background. Evidence rankings do not consider equally internal (IV), external (EV), and model validity (MV) for clinical studies including complementary and alternative medicine/integrative medicine (CAM/IM) research. This paper describe this model and offers an EV assessment tool (EVAT©) for weighing studies according to EV and MV in addition to IV. Methods. An abbreviated systematic review methodology was employed to search, assemble, and evaluate the literature that has been published on EV/MV criteria. Standard databases were searched for keywords relating to EV, MV, and bias-scoring from inception to Jan 2013. Tools identified and concepts described were pooled to assemble a robust tool for evaluating these quality criteria. Results. This study assembled a streamlined, objective tool to incorporate for the evaluation of quality of EV/MV research that is more sensitive to CAM/IM research. Conclusion. Improved reporting on EV can help produce and provide information that will help guide policy makers, public health researchers, and other scientists in their selection, development, and improvement in their research-tested intervention. Overall, clinical studies with high EV have the potential to provide the most useful information about “real-world” consequences of health interventions. It is hoped that this novel tool which considers IV, EV, and MV on equal footing will better guide clinical decision making. PMID:24734111

Photoabsorption and S 2p photoionization of the SF6 molecule: resonances in the excitation energy range of 200-280 eV.

PubMed

Stener, M; Bolognesi, P; Coreno, M; O'Keeffe, P; Feyer, V; Fronzoni, G; Decleva, P; Avaldi, L; Kivimäki, A

2011-05-07

Photoabsorption and S 2p photoionization of the SF(6) molecule have been studied experimentally and theoretically in the excitation energy range up to 100 eV above the S 2p ionization potentials. In addition to the well-known 2t(2g) and 4e(g) shape resonances, the spin-orbit-resolved S 2p photoionization cross sections display two weak resonances between 200 and 210 eV, a wide resonance around 217 eV, a Fano-type resonance around 240 eV, and a second wide resonance around 260 eV. Calculations based on time-dependent density functional theory allow us to assign the 217-eV and 260-eV features to the shape resonances in S 2p photoionization. The Fano resonance is caused by the interference between the direct S 2p photoionization channel and the resonant channel that results from the participator decay of the S 2s(-1)6t(1u) excited state. The weak resonances below 210-eV photon energy, not predicted by theory, are tentatively suggested to originate from the coupling between S 2p shake-up photoionization and S 2p single-hole photoionization. The experimental and calculated angular anisotropy parameters for S 2p photoionization are in good agreement.

7.87 eV Laser Desorption Postionization Mass Spectrometry of Adsorbed and Covalently Bound Bisphenol A Diglycidyl Methacrylate

PubMed Central

Zhou, Manshui; Wu, Chunping; Akhmetov, Artem; Edirisinghe, Praneeth D.; Drummond, James L.; Hanley, Luke

2007-01-01

Bisphenol A diglycidyl methacrylate (Bis-GMA) was adsorbed onto or covalently bound to a porous silicon oxide surface. Laser desorption 10.5 eV postionization mass spectrometry (LDPI-MS) was previously demonstrated for surface analysis of adsorbed and surface bound Bis-GMA, but signal to noise levels were low and ion fragmentation was extensive. 7.87 eV postionization using the fluorine laser was demonstrated here for Bis-GMA. However, signal levels remained low for LDPI-MS of Bis-GMA as its ionization potential was only ∼7.8 eV, near threshold for single photon ionization by the 7.87 eV fluorine laser. It is known that aromatic tagging of molecular analytes can lower the overall IP of the tagged molecular complex, allowing 7.87 eV single photon ionization. Therefore, Bis-GMA was also derivatized with several tags whose IPs were either below or above 7.87 eV: the tag with an IP below 7.87 eV enhanced single photon ionization while the tags with higher IPs did not. However, signal intensities were enhanced by resonant laser desorption for two of the derivatized Bis-GMAs. Intact ions of Bis-GMA and its derivatives were generally observed by 7.87 eV LDPI-MS, consistent with the formation of ions with relatively little internal energy upon threshold single photon ionization. PMID:17449273

Long-range, low-cost electric vehicles enabled by robust energy storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ping; Ross, Russel; Newman, Aron

2015-09-18

ABSTRACT A variety of inherently robust energy storage technologies hold the promise to increase the range and decrease the cost of electric vehicles (EVs). These technologies help diversify approaches to EV energy storage, complementing current focus on high specific energy lithium-ion batteries. The need for emission-free transportation and a decrease in reliance on imported oil has prompted the development of EVs. To reach mass adoption, a significant reduction in cost and an increase in range are needed. Using the cost per mile of range as the metric, we analyzed the various factors that contribute to the cost and weight ofmore » EV energy storage systems. Our analysis points to two primary approaches for minimizing cost. The first approach, of developing redox couples that offer higher specific energy than state-of-the-art lithium-ion batteries, dominates current research effort, and its challenges and potentials are briefly discussed. The second approach represents a new insight into the EV research landscape. Chemistries and architectures that are inherently more robust reduce the need for system protection and enables opportunities of using energy storage systems to simultaneously serve vehicle structural functions. This approach thus enables the use of low cost, lower specific energy chemistries without increasing vehicle weight. Examples of such systems include aqueous batteries, flow cells, and all solid-state batteries. Research progress in these technical areas is briefly reviewed. Potential research directions that can enable low-cost EVs using multifunctional energy storage technologies are described.« less

Oxygen partial pressure influenced structural and optical properties of DC magnetron sputtered ZrO{sub 2} films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondaiah, P.; Madhavi, V.; Uthanna, S.

2013-02-05

Thin films of zirconium oxide (ZrO{sub 2}) were deposited on (100) p-silicon and quartz substrates by sputtering of metallic zirconium target under different oxygen partial pressures in the range 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa. The effect of oxygen partial pressure on the structural and optical properties of the deposited films was systematically investigated. The deposition rate of the films decreased from 3.3 to 1.83 nm/min with the increase of oxygen partial pressure from 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa respectively. The X-ray diffraction profiles revealed that the films exhibit (111) refection of zirconium oxide in monoclinic phase.more » The optical band gap of the films increased from 5.62 to 5.80 eV and refractive index increased from 2.01 to 2.08 with the increase of oxygen partial pressure from 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa respectively.« less

The multi-targeted kinase inhibitor sorafenib inhibits enterovirus 71 replication by regulating IRES-dependent translation of viral proteins.

PubMed

Gao, Meng; Duan, Hao; Liu, Jing; Zhang, Hao; Wang, Xin; Zhu, Meng; Guo, Jitao; Zhao, Zhenlong; Meng, Lirong; Peng, Yihong

2014-06-01

The activation of ERK and p38 signal cascade in host cells has been demonstrated to be essential for picornavirus enterovirus 71 (EV71) replication and up-regulation of virus-induced cyclooxygenase-2 (COX-2)/prostaglandins E2 (PGE2) expression. The aim of this study was to examine the effects of sorafenib, a clinically approved anti-cancer multi-targeted kinase inhibitor, on the propagation and pathogenesis of EV71, with a view to its possible mechanism and potential use in the design of therapy regimes for Hand foot and mouth disease (HFMD) patients with life threatening neurological complications. In this study, non-toxic concentrations of sorafenib were shown to inhibit the yield of infectious progeny EV71 (clinical BC08 strain) by about 90% in three different cell types. A similar inhibitory effect of sorafenib was observed on the synthesis of both viral genomic RNA and the VP1 protein. Interestingly, sorafenib exerted obvious inhibition of the EV71 internal ribosomal entry site (IRES)-mediated translation, the first step in picornavirus replication, by linking it to a firefly luciferase reporter gene. Sorafenib was also able to prevent both EV71-induced CPE and the activation of ERK and p38, which contributes to up-regulation COX-2/PGE2 expression induced by the virus. Overall, this study shows that sorafenib strongly inhibits EV71 replication at least in part by regulating viral IRES-dependent translation of viral proteins, indicating a novel potential strategy for the treatment of HFMD patients with severe neurological complications. To our knowledge, this is the first report that investigates the mechanism by which sorafenib inhibits EV71 replication. Copyright © 2014 Elsevier B.V. All rights reserved.

Impact of polyphenols on extracellular vesicle levels and effects and their properties as tools for drug delivery for nutrition and health.

PubMed

Soleti, Raffaella; Andriantsitohaina, Ramaroson; Martinez, M Carmen

2018-04-15

Polyphenols are found in plant-derived foods and beverages and display numerous protective effects against cancers, cardiovascular, metabolic and neurodegenerative diseases. Extracellular vesicles (EVs), microparticles, exosomes, and apoptotic bodies, originated by different cell types are emerging as a novel mean of cell-to-cell communication in physiology and pathology and represent a new way to convey fundamental information between cells. Polyphenols can act on signaling pathways that interfere with the biogenesis of EVs. Thus, they are able to control EV release from cells and their content and therefore their functional properties. Both EVs and polyphenols are therapeutic tools that can be used against several diseases. In this context, the combination of both tools can increase their therapeutic potential. Three types of strategies can be used: (i) plants are able to produce EVs that encapsulate natural components from vegetables, polyphenols for instance, (ii) mammalian cells can be treated with polyphenols and the subsequent EVs produced are enriched in these components, and (iii) EVs from mammalian cells can be uploaded with polyphenols. We review the novel aspects of the interplay between polyphenols and EVs that could trigger and improve the health benefits in cancer, cardiovascular, metabolic and neurodegenerative diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

Choices and changes: Eccles' Expectancy-Value model and upper-secondary school students' longitudinal reflections about their choice of a STEM education

NASA Astrophysics Data System (ADS)

Lykkegaard, Eva; Ulriksen, Lars

2016-03-01

During the past 30 years, Eccles' comprehensive social-psychological Expectancy-Value Model of Motivated Behavioural Choices (EV-MBC model) has been proven suitable for studying educational choices related to Science, Technology, Engineering and/or Mathematics (STEM). The reflections of 15 students in their last year in upper-secondary school concerning their choice of tertiary education were examined using quantitative EV-MBC surveys and repeated qualitative interviews. This article presents the analyses of three cases in detail. The analytical focus was whether the factors indicated in the EV-MBC model could be used to detect significant changes in the students' educational choice processes. An important finding was that the quantitative EV-MBC surveys and the qualitative interviews gave quite different results concerning the students' considerations about the choice of tertiary education, and that significant changes in the students' reflections were not captured by the factors of the EV-MBC model. This questions the validity of the EV-MBC surveys. Moreover, the quantitative factors from the EV-MBC model did not sufficiently explain students' dynamical educational choice processes where students in parallel considered several different potential educational trajectories. We therefore call for further studies of the EV-MBC model's use in describing longitudinal choice processes and especially in investigating significant changes.

Phylodynamics of Enterovirus A71-Associated Hand, Foot, and Mouth Disease in Viet Nam.

PubMed

Geoghegan, Jemma L; Tan, Le Van; Kühnert, Denise; Halpin, Rebecca A; Lin, Xudong; Simenauer, Ari; Akopov, Asmik; Das, Suman R; Stockwell, Timothy B; Shrivastava, Susmita; Ngoc, Nghiem My; Uyen, Le Thi Tam; Tuyen, Nguyen Thi Kim; Thanh, Tran Tan; Hang, Vu Thi Ty; Qui, Phan Tu; Hung, Nguyen Thanh; Khanh, Truong Huu; Thinh, Le Quoc; Nhan, Le Nguyen Thanh; Van, Hoang Minh Tu; Viet, Do Chau; Tuan, Ha Manh; Viet, Ho Lu; Hien, Tran Tinh; Chau, Nguyen Van Vinh; Thwaites, Guy; Grenfell, Bryan T; Stadler, Tanja; Wentworth, David E; Holmes, Edward C; Van Doorn, H Rogier

2015-09-01

Enterovirus A71 (EV-A71) is a major cause of hand, foot, and mouth disease (HFMD) and is particularly prevalent in parts of Southeast Asia, affecting thousands of children and infants each year. Revealing the evolutionary and epidemiological dynamics of EV-A71 through time and space is central to understanding its outbreak potential. We generated the full genome sequences of 200 EV-A71 strains sampled from various locations in Viet Nam between 2011 and 2013 and used these sequence data to determine the evolutionary history and phylodynamics of EV-A71 in Viet Nam, providing estimates of the effective reproduction number (Re) of the infection through time. In addition, we described the phylogeography of EV-A71 throughout Southeast Asia, documenting patterns of viral gene flow. Accordingly, our analysis reveals that a rapid genogroup switch from C4 to B5 likely took place during 2012 in Viet Nam. We show that the Re of subgenogroup C4 decreased during the time frame of sampling, whereas that of B5 increased and remained >1 at the end of 2013, corresponding to a rise in B5 prevalence. Our study reveals that the subgenogroup B5 virus that emerged into Viet Nam is closely related to variants that were responsible for large epidemics in Malaysia and Taiwan and therefore extends our knowledge regarding its associated area of endemicity. Subgenogroup B5 evidently has the potential to cause more widespread outbreaks across Southeast Asia. EV-A71 is one of many viruses that cause HFMD, a common syndrome that largely affects infants and children. HFMD usually causes only mild illness with no long-term consequences. Occasionally, however, severe infection may arise, especially in very young children, causing neurological complications and even death. EV-A71 is highly contagious and is associated with the most severe HFMD cases, with large and frequent epidemics of the virus recorded worldwide. Although major advances have been made in the development of a potential EV-A71 vaccine, there is no current prevention and little is known about the patterns and dynamics of EV-A71 spread. In this study, we utilize full-length genome sequence data obtained from HFMD patients in Viet Nam, a geographical region where the disease has been endemic since 2003, to characterize the phylodynamics of this important emerging virus. Copyright © 2015 Geoghegan et al.

Phylodynamics of Enterovirus A71-Associated Hand, Foot, and Mouth Disease in Viet Nam

PubMed Central

Kühnert, Denise; Halpin, Rebecca A.; Lin, Xudong; Simenauer, Ari; Akopov, Asmik; Das, Suman R.; Stockwell, Timothy B.; Shrivastava, Susmita; Ngoc, Nghiem My; Uyen, Le Thi Tam; Tuyen, Nguyen Thi Kim; Thanh, Tran Tan; Hang, Vu Thi Ty; Qui, Phan Tu; Hung, Nguyen Thanh; Khanh, Truong Huu; Thinh, Le Quoc; Nhan, Le Nguyen Thanh; Van, Hoang Minh Tu; Viet, Do Chau; Tuan, Ha Manh; Viet, Ho Lu; Hien, Tran Tinh; Chau, Nguyen Van Vinh; Thwaites, Guy; Grenfell, Bryan T.; Stadler, Tanja; Wentworth, David E.; Holmes, Edward C.; Van Doorn, H. Rogier

2015-01-01

ABSTRACT Enterovirus A71 (EV-A71) is a major cause of hand, foot, and mouth disease (HFMD) and is particularly prevalent in parts of Southeast Asia, affecting thousands of children and infants each year. Revealing the evolutionary and epidemiological dynamics of EV-A71 through time and space is central to understanding its outbreak potential. We generated the full genome sequences of 200 EV-A71 strains sampled from various locations in Viet Nam between 2011 and 2013 and used these sequence data to determine the evolutionary history and phylodynamics of EV-A71 in Viet Nam, providing estimates of the effective reproduction number (Re) of the infection through time. In addition, we described the phylogeography of EV-A71 throughout Southeast Asia, documenting patterns of viral gene flow. Accordingly, our analysis reveals that a rapid genogroup switch from C4 to B5 likely took place during 2012 in Viet Nam. We show that the Re of subgenogroup C4 decreased during the time frame of sampling, whereas that of B5 increased and remained >1 at the end of 2013, corresponding to a rise in B5 prevalence. Our study reveals that the subgenogroup B5 virus that emerged into Viet Nam is closely related to variants that were responsible for large epidemics in Malaysia and Taiwan and therefore extends our knowledge regarding its associated area of endemicity. Subgenogroup B5 evidently has the potential to cause more widespread outbreaks across Southeast Asia. IMPORTANCE EV-A71 is one of many viruses that cause HFMD, a common syndrome that largely affects infants and children. HFMD usually causes only mild illness with no long-term consequences. Occasionally, however, severe infection may arise, especially in very young children, causing neurological complications and even death. EV-A71 is highly contagious and is associated with the most severe HFMD cases, with large and frequent epidemics of the virus recorded worldwide. Although major advances have been made in the development of a potential EV-A71 vaccine, there is no current prevention and little is known about the patterns and dynamics of EV-A71 spread. In this study, we utilize full-length genome sequence data obtained from HFMD patients in Viet Nam, a geographical region where the disease has been endemic since 2003, to characterize the phylodynamics of this important emerging virus. PMID:26085170

Genotyping of enteroviruses isolated in Kenya from pediatric patients using partial VP1 region.

PubMed

Opanda, Silvanos M; Wamunyokoli, Fred; Khamadi, Samoel; Coldren, Rodney; Bulimo, Wallace D

2016-01-01

Enteroviruses (EV) are responsible for a wide range of clinical diseases in humans. Though studied broadly in several regions of the world, the genetic diversity of human enteroviruses (HEV) circulating in the sub-Saharan Africa remains under-documented. In the current study, we molecularly typed 61 HEV strains isolated in Kenya between 2008 and 2011 targeting the 3'-end of the VP1 gene. Viral RNA was extracted from the archived isolates and part of the VP1 gene amplified by RT-PCR, followed by sequence analysis. Twenty-two different EV types were detected. Majority (72.0 %) of these belonged to Enterovirus B species followed by Enterovirus D (21.3 %) and Enterovirus A (6.5 %). The most frequently detected types were Enterovirus-D68 (EV-D68), followed by Coxsackievirus B2 (CV-B2), CV-B1, CV-B4 and CV-B3. Phylogenetic analyses of these viruses revealed that Kenyan CV-B1 isolates were segregated among sequences of global CV-B1 strains. Conversely, the Kenyan CV-B2, CV-B3, CV-B4 and EV-D68 strains generally grouped together with those detected from other countries. Notably, the Kenyan EV-D68 strains largely clustered with sequences of global strains obtained between 2008 and 2010 than those circulating in recent years. Overall, our results indicate that HEV strains belonging to Enterovirus D and Enterovirus B species pre-dominantly circulated and played a significant role in pediatric respiratory infection in Kenya, during the study period. The Kenyan CV-B1 strains were genetically divergent from those circulating in other countries. Phylogenetic clustering of Kenyan EV-D68 strains with sequences of global strains circulating between 2008 and 2010 than those obtained in recent years suggests a high genomic variability associated with the surface protein encoding VP1 gene in these enteroviruses.

Positron-alkali atom scattering

NASA Technical Reports Server (NTRS)

Mceachran, R. P.; Horbatsch, M.; Stauffer, A. D.; Ward, S. J.

1990-01-01

Positron-alkali atom scattering was recently investigated both theoretically and experimentally in the energy range from a few eV up to 100 eV. On the theoretical side calculations of the integrated elastic and excitation cross sections as well as total cross sections for Li, Na and K were based upon either the close-coupling method or the modified Glauber approximation. These theoretical results are in good agreement with experimental measurements of the total cross section for both Na and K. Resonance structures were also found in the L = 0, 1 and 2 partial waves for positron scattering from the alkalis. The structure of these resonances appears to be quite complex and, as expected, they occur in conjunction with the atomic excitation thresholds. Currently both theoretical and experimental work is in progress on positron-Rb scattering in the same energy range.

Some photophysical properties of new oligomer obtained from anodic oxidation of 4,4‧-dimethoxychalcone

NASA Astrophysics Data System (ADS)

Ghomrasni, S.; Aribi, I.; Chemek, M.; Said, A. Haj; Alimi, K.

2018-04-01

Some photopysical properties of a new oligomer obtained from the anodic oxidation of the 4,4‧-dimethoxy-chalcone were investigated using different and complementary techniques. Firstly, TGA analysis and X-Ray diffraction experiments showed that the oligomer is thermally stable up to 500 K and partially organized at the solid state, respectively. Secondly, the optical properties of the oligomer were studied in solution and in the solid state. The optical band gap was estimated to be 3.17 eV in solution state and 2.70 eV in film state. What's more, the fluorescence decay is determined showing a considerably faster in the film state (0.183 ns) than in solution state (1.606 ns), due to the rapid non-radiative decay at inter-chain trap sites.

Prediction of electronic and optical properties of ZnAl2Te4 defect chalcopyrite semiconductor: an ab-initio study

NASA Astrophysics Data System (ADS)

Mayengbam, Rishikanta; Tripathy, S. K.; Pandey, B. P.

2018-03-01

In this paper, we have investigated the structural, electronic and optical properties of ZnAl2Te4 defect chalcopyrite semiconductor using generalized gradient approximation (GGA) within density functional theory (DFT). We have calculated the optimized lattice constants (a and c) and compared with the available experimental values. The optimized lattice constants have been used to calculate the energy band gap and found to be 1.57 eV. The partial density of states and total density of states have been discussed in detail. The frequency dependent dielectric constant and refractive index have been calculated and plotted in the energy range 0-13 eV. All the above parameters have been compared with the available experimental and theoretical values and found good agreement between them.

Stem Cell Extracellular Vesicles: Extended Messages of Regeneration

PubMed Central

Riazifar, Milad; Pone, Egest J.; Lötvall, Jan; Zhao, Weian

2017-01-01

Stem cells are critical to maintaining steady-state organ homeostasis and regenerating injured tissues. Recent intriguing reports implicate extracellular vesicles (EVs) as carriers for the distribution of morphogens and growth and differentiation factors from tissue parenchymal cells to stem cells, and conversely, stem cell–derived EVs carrying certain proteins and nucleic acids can support healing of injured tissues. We describe approaches to make use of engineered EVs as technology platforms in therapeutics and diagnostics in the context of stem cells. For some regenerative therapies, natural and engineered EVs from stem cells may be superior to single-molecule drugs, biologics, whole cells, and synthetic liposome or nanoparticle formulations because of the ease of bioengineering with multiple factors while retaining superior biocompatibility and biostability and posing fewer risks for abnormal differentiation or neoplastic transformation. Finally, we provide an overview of current challenges and future directions of EVs as potential therapeutic alternatives to cells for clinical applications. PMID:27814025

Impact of lysosome status on extracellular vesicle content and release.

PubMed

Eitan, Erez; Suire, Caitlin; Zhang, Shi; Mattson, Mark P

2016-12-01

Extracellular vesicles (EVs) are nanoscale size bubble-like membranous structures released from cells. EVs contain RNA, lipids and proteins and are thought to serve various roles including intercellular communication and removal of misfolded proteins. The secretion of misfolded and aggregated proteins in EVs may be a cargo disposal alternative to the autophagy-lysosomal and ubiquitin-proteasome pathways. In this review we will discuss the importance of lysosome functionality for the regulation of EV secretion and content. Exosomes are a subtype of EVs that are released by the fusion of multivesicular bodies (MVB) with the plasma membrane. MVBs can also fuse with lysosomes, and the trafficking pathway of MVBs can therefore determine whether or not exosomes are released from cells. Here we summarize data from studies of the effects of lysosome inhibition on the secretion of EVs and on the possibility that cells compensate for lysosome malfunction by disposal of potentially toxic cargos in EVs. A better understanding of the molecular mechanisms that regulate trafficking of MVBs to lysosomes and the plasma membrane may advance an understanding of diseases in which pathogenic proteins, lipids or infectious agents accumulate within or outside of cells. Copyright © 2016. Published by Elsevier B.V.

Impact of Lysosome Status on Extracellular Vesicle Content and Release

PubMed Central

Eitan, Erez; Suire, Caitlin; Zhang, Shi; Mattson, Mark P.

2016-01-01

Extracellular vesicles (EVs) are nanoscale size bubble-like membranous structures released from cells. EVs contain RNA, lipids and proteins and are thought to serve various roles including intercellular communication and removal of misfolded proteins. The secretion of misfolded and aggregated proteins in EVs may be a cargo disposal alternative to the autophagy-lysosomal and ubiquitin-proteasome pathways. In this review we will discuss the importance of lysosome functionality for the regulation of EV secretion and content. Exosomes are a subtype of EVs that are released by the fusion of multivesicular bodies (MVB) with the plasma membrane. MVBs can also fuse with lysosomes, and the trafficking pathway of MVBs can therefore determine whether or not exosomes are released from cells. Here we summarize data from studies of the effects of lysosome inhibition on the secretion of EVs and on the possibility that cells compensate for lysosome malfunction by disposal of potentially toxic cargos in EVs. A better understanding of the molecular mechanisms that regulate trafficking of MVBs to lysosomes and the plasma membrane may advance an understanding of diseases in which pathogenic proteins, lipids or infectious agents accumulate within or outside of cells. PMID:27238186

FLIM reveals alternative EV-mediated cellular up-take pathways of paclitaxel.

PubMed

Saari, H; Lisitsyna, E; Rautaniemi, K; Rojalin, T; Niemi, L; Nivaro, O; Laaksonen, T; Yliperttula, M; Vuorimaa-Laukkanen, E

2018-06-15

In response to physiological and artificial stimuli, cells generate nano-scale extracellular vesicles (EVs) by encapsulating biomolecules in plasma membrane-derived phospholipid envelopes. These vesicles are released to bodily fluids, hence acting as powerful endogenous mediators in intercellular signaling. EVs provide a compelling alternative for biomarker discovery and targeted drug delivery, but their kinetics and dynamics while interacting with living cells are poorly understood. Here we introduce a novel method, fluorescence lifetime imaging microscopy (FLIM) to investigate these interaction attributes. By FLIM, we show distinct cellular uptake mechanisms of different EV subtypes, exosomes and microvesicles, loaded with anti-cancer agent, paclitaxel. We demonstrate differences in intracellular behavior and drug release profiles of paclitaxel-containing EVs. Exosomes seem to deliver the drug mostly by endocytosis while microvesicles enter the cells by both endocytosis and fusion with cell membrane. This research offers a new real-time method to investigate EV kinetics with living cells, and it is a potential advancement to complement the existing techniques. The findings of this study improve the current knowledge in exploiting EVs as next-generation targeted drug delivery systems. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

The Emerging Role of Extracellular Vesicle-Mediated Drug Resistance in Cancers: Implications in Advanced Prostate Cancer.

PubMed

Soekmadji, Carolina; Nelson, Colleen C

2015-01-01

Emerging evidence has shown that the extracellular vesicles (EVs) regulate various biological processes and can control cell proliferation and survival, as well as being involved in normal cell development and diseases such as cancers. In cancer treatment, development of acquired drug resistance phenotype is a serious issue. Recently it has been shown that the presence of multidrug resistance proteins such as Pgp-1 and enrichment of the lipid ceramide in EVs could have a role in mediating drug resistance. EVs could also mediate multidrug resistance through uptake of drugs in vesicles and thus limit the bioavailability of drugs to treat cancer cells. In this review, we discussed the emerging evidence of the role EVs play in mediating drug resistance in cancers and in particular the role of EVs mediating drug resistance in advanced prostate cancer. The role of EV-associated multidrug resistance proteins, miRNA, mRNA, and lipid as well as the potential interaction(s) among these factors was probed. Lastly, we provide an overview of the current available treatments for advanced prostate cancer, considering where EVs may mediate the development of resistance against these drugs.

Anti-enterovirus 71 activity screening of chinese herbs with anti-infection and inflammation activities.

PubMed

Lin, Tzou-Yien; Liu, Yi-Chun; Jheng, Jia-Rong; Tsai, Hui-Ping; Jan, Jia-Tsrong; Wong, Wen-Rou; Horng, Jim-Tong

2009-01-01

Antipyretic and toxin-eliminating traditional Chinese herbs are believed to possess antiviral activity. In this study, we screened extracts of 22 herbs for activity against enterovirus 71 (EV71). We found that only extracts of Houttuynia cordata Thunb. could neutralize EV71-induced cytopathic effects in Vero cells. The 50% inhibitory concentration of H. cordata extract for EV71 was 125.92 +/- 27.84 mug/ml. Antiviral screening of herb extracts was also conducted on 3 genotypes of EV71, coxsackievirus A16 and echovirus 9. H. cordata extract had the highest activity against genotype A of EV71. A plaque reduction assay showed that H. cordata extract significantly reduced plaque formation. Viral protein expression, viral RNA synthesis and virus-induced caspase 3 activation were inhibited in the presence of H. cordata extract, suggesting that it affected apoptotic processes in EV71-infected Vero cells by inhibiting viral replication. The antiviral activity of H. cordata extract was greater in cells pretreated with extract than those treated after infection. We conclude that H. cordata extract has antiviral activity, and it offers a potential to develop a new anti-EV71 agent.

Berberine inhibits enterovirus 71 replication by downregulating the MEK/ERK signaling pathway and autophagy.

PubMed

Wang, Huiqiang; Li, Ke; Ma, Linlin; Wu, Shuo; Hu, Jin; Yan, Haiyan; Jiang, Jiandong; Li, Yuhuan

2017-01-11

The MEK-ERK signaling pathway and autophagy play an important role for enterovirus71(EV71) replication. Inhibition of MEK-ERK signaling pathway and autophagy is shown to impair EV71 replication. Berberine (BBR), an isoquinoline alkaloid isolated from Berberis vulgaris L., has been reported to have ability to regulate this signaling pathway and autophagy. Herein, we want to determine whether berberine can inhibit EV71 infection by downregulating the MEK/ERK signaling pathway and autophagy. The antiviral effect of berberine was determined by cytopathic effect (CPE) assay, western blotting assay and qRT-PCR assay. The mechanism of BBR anti-virus was determined by western blotting assay and immunofluorescence assay. We showed that berberine does-dependently reduced EV71 RNA and protein synthesis, which was, at least in part, the result of inhibition of activation of MEK/ERK signaling pathway. Furthermore, we found that berberine suppressed the EV71-induced autophagy by activating AKT protein and inhibiting the phosphorylation of JNK and PI3KIII. BBR inhibited EV71 replication by downregulating autophagy and MEK/ERK signaling pathway. These findings suggest that BBR may be a potential agent or supplement against EV71 infection.

Enterovirus genotypes causing hand foot and mouth disease in Shanghai, China: a molecular epidemiological analysis.

PubMed

Xu, Menghua; Su, Liyun; Cao, Lingfeng; Zhong, Huaqing; Dong, Niuniu; Xu, Jin

2013-10-22

A rapid expansion of hand, foot, and mouth disease (HFMD) outbreaks has occurred and caused deaths in China in recent years, but little is known about the other etiologic agents except enterovirus 71 (EV71) and coxsackievirus A 16 (CA16). The objective of this study is to determine the genotype compositions of enterovirus causing HFMD in Shanghai and identify any associations between enterovirus types and clinical manifestations. Stool specimens were collected from patients hospitalized for treatment of HFMD, from May 2010 to April 2011. Enterovirus was detected by reverse transcription PCR and directly genotyped by sequencing the PCR products. Phylogenetic analysis was based on the VP1 partial gene. Of 290 specimens, 277 (95.5%) tested positive for enterovirus. The major genotypes were EV71 (63.8%), CA10 (9.0%), CA6 (8.3%), CA16 (6.9%), CA12 (2.4%), and CA4 (1.4%). The EV71 strains belonged to the C4a subtype and CA16 belonged to the B subtype. CA6 was closely related to strains detected in Japan, Taiwan and China, and CA10, CA12 and CA4 were phylogenetically similar to other strains circulating in China. Mean hospital stays and the prevalence of complications in patients with EV71 infection were higher than those in patients in CA6, CA10 or CA16 infection (P < 0.05 for all comparisons). Children with CA12 infection were the youngest, and most likely have the highest risk of complications when compared to the other non-EV71 infection groups. This study demonstrated a diversified pathogen compositions attributing to HFMD and clinical symptoms differing in enterovirus genotypes. It deserves our attention as early identification of enterovirus genotypes is important for diagnosis and treatment of HFMD patients.

Interface energy band alignment at the all-transparent p-n heterojunction based on NiO and BaSnO3

NASA Astrophysics Data System (ADS)

Zhang, Jiaye; Han, Shaobo; Luo, Weihuang; Xiang, Shuhuai; Zou, Jianli; Oropeza, Freddy E.; Gu, Meng; Zhang, Kelvin H. L.

2018-04-01

Transparent oxide semiconductors hold great promise for many optoelectronic devices such as transparent electronics, UV-emitting devices, and photodetectors. A p-n heterojunction is the most ubiquitous building block to realize these devices. In this work, we report the fabrication and characterization of the interface properties of a transparent heterojunction consisting of p-type NiO and n-type perovskite BaSnO3. We show that high-quality NiO thin films can be epitaxially grown on BaSnO3 with sharp interfaces because of a small lattice mismatch (˜1.3%). The diode fabricated from this heterojunction exhibits rectifying behavior with a ratio of 500. X-ray photoelectron spectroscopy reveals a type II or "staggered" band alignment with valence and conduction band offsets of 1.44 eV and 1.86 eV, respectively. Moreover, a large upward band bending potential of 0.90 eV for BaSnO3 and a downward band bending potential of 0.15 eV for NiO were observed in the interface region. Such electronic properties have important implication for optoelectronic applications as the large built-in potential provides favorable energetics for photo-generated electron-hole separation/migration.

Management of the 2014 Enterovirus 68 Outbreak at a Pediatric Tertiary Care Center.

PubMed

Schuster, Jennifer E; Newland, Jason G

2015-11-01

Enterovirus 68 (EV-D68) is an uncommonly recognized cause of acute respiratory tract infections. During the late summer of 2014, an international EV-D68 outbreak occurred. We review the steps of outbreak recognition and management in the context of 1 hospital's experience with the EV-D68 outbreak. We reviewed the role of Children's Mercy Hospital as one of the first hospitals to recognize the 2014 EV-D68 outbreak in the United States. The steps of outbreak management were applied to real-life examples as the outbreak unfolded at our hospital. Management of the 2014 EV-D68 outbreak was a multifaceted effort requiring close coordination with hospitals, local and state health departments, and the Centers for Disease Control and Prevention. The importance of clear and frequent communication is highlighted both intra- and interinstitutionally. Increased respiratory disease-related pediatric admissions at hospitals nationally were attributed to EV-D68. Outcomes for these children, including the association of EV-D68 with acute flaccid myelitis, remain under investigation. Following the steps of outbreak management is critical to providing optimal patient care and ensuring the health of the public. During the 2014 EV-D68 outbreak, close adherence to outbreak principles led to swift recognition of illness, rapid diagnostic measures, institution of appropriate therapies, and dissemination of information to health care providers and the public. Equally important was the subsequent identification of an increase in acute flaccid myelitis cases against the backdrop of an increase in EV-D68 detections nationally. Future prospective studies are needed to determine the true burden of EV-D68 disease, potential vaccines and therapeutics, and outcomes of children with EV-D68 infection. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

Coriolis-coupled wave packet dynamics of H + HLi reaction.

PubMed

Padmanaban, R; Mahapatra, S

2006-05-11

We investigated the effect of Coriolis coupling (CC) on the initial state-selected dynamics of H+HLi reaction by a time-dependent wave packet (WP) approach. Exact quantum scattering calculations were obtained by a WP propagation method based on the Chebyshev polynomial scheme and ab initio potential energy surface of the reacting system. Partial wave contributions up to the total angular momentum J=30 were found to be necessary for the scattering of HLi in its vibrational and rotational ground state up to a collision energy approximately 0.75 eV. For each J value, the projection quantum number K was varied from 0 to min (J, K(max)), with K(max)=8 until J=20 and K(max)=4 for further higher J values. This is because further higher values of K do not have much effect on the dynamics and also because one wishes to maintain the large computational overhead for each calculation within the affordable limit. The initial state-selected integral reaction cross sections and thermal rate constants were calculated by summing up the contributions from all partial waves. These were compared with our previous results on the title system, obtained within the centrifugal sudden and J-shifting approximations, to demonstrate the impact of CC on the dynamics of this system.

Stabilized wide bandgap perovskite solar cells by tin substitution

DOE PAGES

Yang, Zhibin; Rajagopal, Adharsh; Jo, Sae Byeok; ...

2016-11-16

Wide bandgap MAPb(I 1-yBr y) 3 perovskites show promising potential for application in tandem solar cells. However, unstable photovoltaic performance caused by phase segregation has been observed under illumination when y is above 0.2. Herein, we successfully demonstrate stabilization of the I/Br phase by partially replacing Pb 2+ with Sn 2+ and verify this stabilization with X-ray diffractometry and transient absorption spectroscopy. The resulting MAPb 0.75Sn 0.25(I 1-yBr y) 3 perovskite solar cells show stable photovoltaic performance under continuous illumination. Among these cells, the one based on MAPb 0.75Sn 0.25(I 0.4Br 0.6) 3 perovskite shows the highest efficiency of 12.59%more » with a bandgap of 1.73 eV, which make it a promising wide bandgap candidate for application in tandem solar cells. The engineering of internal bonding environment by partial Sn substitution is believed to be the main reason for making MAPb 0.75Sn 0.25(I 1-yBr y) 3 perovskite less vulnerable to phase segregation during the photostriction under illumination. Furthermore, this study establishes composition engineering of the metal site as a promising strategy to impart phase stability in hybrid perovskites under illumination.« less

A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions.

PubMed

Brown, Matthew A; Redondo, Amaia Beloqui; Jordan, Inga; Duyckaerts, Nicolas; Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Müächler, Jean-Pierre; Birrer, Mario; Honegger, Juri; Wetter, Reto; Wörner, Hans Jakob; van Bokhoven, Jeroen A

2013-07-01

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II α lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.

Exposure to Violence, Perceived Peer Relationships, and Corresponding Psychological Sequelae

ERIC Educational Resources Information Center

Bender, Jade A.; Roberts, Michael C.

2009-01-01

As children's exposure to violence (EV) has become more evident, concern for the implications that violence has on children has risen. Consequently, researchers have explored the relationship between exposure and outcomes, as well as potential mediators and moderators. In this study, we (a) examined EV in a sample of children from the Midwestern…

Vibrational structure in the photo-electron spectrum of O2+2Sigma(g)-(sigmag2s)

NASA Technical Reports Server (NTRS)

Gardner, J. L.; Samson, J. A. R.

1974-01-01

Discrete vibrational structure has been observed in the photo-electron spectrum of oxygen at an ionization potential of 40.33 eV. Two levels, attributed to the 02(+) 2 sigma g- final state, have been detected with a vibrational spacing of 0.071 eV.

A theoretical study of the photoinduced desorption of I — from a CF3I dimer

NASA Astrophysics Data System (ADS)

Tossell, J. A.

1997-04-01

Ab initio SCF-MO calculations using effective core-potential basis sets are employed to evaluate ionization potentials and electron affinities for CF3I and the geometries and energies of the singlet and triplet states of the CF3I dimer. The calculated geometry of the single state of the dimer is in qualitative agreement with the experimental geometry for condensed phase CF3I. The calculated energy for vertical excitation from the singlet to the triplet state is 4.1 eV at the Hartree-Fock level and 4.5 eV after incorporation of correlation at the Moller-Plesset 2nd-order level, consistent with excitation by 193 nm (6.4 eV) light. The equilibrium geometry of the triplet consists essentially of a CF3I+, CF3I- ion pair, in which the Csbnd I bond distance in the anionic component has increased to 5.5Å, compared with 2.1Åin the neutral molecule. The calculated binding energy of the triplet ion pair is about 4 eV.

The harmonic impact of electric vehicle battery charging

NASA Astrophysics Data System (ADS)

Staats, Preston Trent

The potential widespread introduction of the electric vehicle (EV) presents both opportunities and challenges to the power systems engineers who will be required to supply power to EV batteries. One of the challenges associated with EV battery charging comes from the potentially high harmonic currents associated with the conversion of ac power system voltages to dc EV battery voltages. Harmonic currents lead to increased losses in distribution circuits and reduced life expectancy of such power distribution components as capacitors and transformers. Harmonic current injections also cause harmonic voltages on power distribution networks. These distorted voltages can affect power system loads and specific standards exist regulating acceptable voltage distortion. This dissertation develops and presents the theory required to evaluate the electric vehicle battery charger as a harmonic distorting load and its possible harmonic impact on various aspects of power distribution systems. The work begins by developing a method for evaluating the net harmonic current injection of a large collection of EV battery chargers which accounts for variation in the start-time and initial battery state-of-charge between individual chargers. Next, this method is analyzed to evaluate the effect of input parameter variation on the net harmonic currents predicted by the model. We then turn to an evaluation of the impact of EV charger harmonic currents on power distribution systems, first evaluating the impact of these currents on a substation transformer and then on power distribution system harmonic voltages. The method presented accounts for the uncertainty in EV harmonic current injections by modeling the start-time and initial battery state-of-charge (SOC) of an individual EV battery charger as random variables. Thus, the net harmonic current, and distribution system harmonic voltages are formulated in a stochastic framework. Results indicate that considering variation in start-time and SOC leads to reduced estimates of harmonic current injection when compared to more traditional methods that do not account for variation. Evaluation of power distribution system harmonic voltages suggests that for any power distribution network there is a definite threshold penetration of EVs, below which the total harmonic distortion of voltage exceeds 5% at an insignificant number of buses. Thus, most existing distribution systems will probably be able to accommodate the early introduction of EV battery charging without widespread harmonic voltage problems.

Detection of prostate cancer-specific transcripts in extracellular vesicles isolated from post-DRE urine

PubMed Central

Pellegrini, Kathryn L.; Patil, Dattatraya; Douglas, Kristen J.S.; Lee, Grace; Wehrmeyer, Kathryn; Torlak, Mersiha; Clark, Jeremy; Cooper, Colin S.; Moreno, Carlos S.; Sanda, Martin G.

2018-01-01

Background The measurement of gene expression in post-digital rectal examination (DRE) urine specimens provides a non-invasive method to determine a patient’s risk of prostate cancer. Many currently available assays use whole urine or cell pellets for the analysis of prostate cancer-associated genes, although the use of extracellular vesicles (EVs) has also recently been of interest. We investigated the expression of prostate-, kidney-, and bladder-specific transcripts and known prostate cancer biomarkers in urine EVs. Methods Cell pellets and EVs were recovered from post-DRE urine specimens, with the total RNA yield and quality determined by Bioanalyzer. The levels of prostate, kidney, and bladder-associated transcripts in EVs were assessed by TaqMan qPCR and targeted sequencing. Results RNA was more consistently recovered from the urine EV specimens, with over 80% of the patients demonstrating higher RNA yields in the EV fraction as compared to urine cell pellets. The median EV RNA yield of 36.4 ng was significantly higher than the median urine cell pellet RNA yield of 4.8 ng. Analysis of the post-DRE urine EVs indicated that prostate-specific transcripts were more abundant than kidney- or bladder-specific transcripts. Additionally, patients with prostate cancer had significantly higher levels of the prostate cancer-associated genes PCA3 and ERG. Conclusions Post-DRE urine EVs are a viable source of prostate-derived RNAs for biomarker discovery and prostate cancer status can be distinguished from analysis of these specimens. Continued analysis of urine EVs offers the potential discovery of novel biomarkers for pre-biopsy prostate cancer detection. PMID:28419548

Detection of prostate cancer-specific transcripts in extracellular vesicles isolated from post-DRE urine.

PubMed

Pellegrini, Kathryn L; Patil, Dattatraya; Douglas, Kristen J S; Lee, Grace; Wehrmeyer, Kathryn; Torlak, Mersiha; Clark, Jeremy; Cooper, Colin S; Moreno, Carlos S; Sanda, Martin G

2017-06-01

The measurement of gene expression in post-digital rectal examination (DRE) urine specimens provides a non-invasive method to determine a patient's risk of prostate cancer. Many currently available assays use whole urine or cell pellets for the analysis of prostate cancer-associated genes, although the use of extracellular vesicles (EVs) has also recently been of interest. We investigated the expression of prostate-, kidney-, and bladder-specific transcripts and known prostate cancer biomarkers in urine EVs. Cell pellets and EVs were recovered from post-DRE urine specimens, with the total RNA yield and quality determined by Bioanalyzer. The levels of prostate, kidney, and bladder-associated transcripts in EVs were assessed by TaqMan qPCR and targeted sequencing. RNA was more consistently recovered from the urine EV specimens, with over 80% of the patients demonstrating higher RNA yields in the EV fraction as compared to urine cell pellets. The median EV RNA yield of 36.4 ng was significantly higher than the median urine cell pellet RNA yield of 4.8 ng. Analysis of the post-DRE urine EVs indicated that prostate-specific transcripts were more abundant than kidney- or bladder-specific transcripts. Additionally, patients with prostate cancer had significantly higher levels of the prostate cancer-associated genes PCA3 and ERG. Post-DRE urine EVs are a viable source of prostate-derived RNAs for biomarker discovery and prostate cancer status can be distinguished from analysis of these specimens. Continued analysis of urine EVs offers the potential discovery of novel biomarkers for pre-biopsy prostate cancer detection. © 2017 Wiley Periodicals, Inc.

Electronic and optical properties of novel carbon allotropes

DOE PAGES

Wang, Zhanyu; Dong, F.; Shen, B.; ...

2016-01-22

The vibrational properties, electronic structures and optical properties of novel carbon allotropes, such as monolayer penta-graphene (PG), double-layer PG and T12-carbon, were studied by first-principles calculations. Results of phonon calculations demonstrate that these exotic carbon allotropes are dynamically stable. The bulk T12 phase is an indirect-gap semiconductor having a quasiparticle (QP) bandgap of ~5.19 eV. When the bulk material transforms to a two-dimensional (2D) phase, the monolayer and double-layer PG become quasi-direct gap semiconductors with smaller QP bandgaps of ~4.48 eV and ~3.67 eV, respectively. Furthermore, the partial charge density analysis indicates that the 2D phases retain part of themore » electronic characteristics of the T12 phase. The linear photon energy-dependent dielectric functions and related optical properties including refractive index, extinction coefficient, absorption spectrum, reflectivity, and energy-loss spectrum were also computed and discussed. Additionally, the chemical stability of monolayer PG and the electronic and optical properties of double-side hydrogenated monolayer PG were also investigated. Furthermore, the results obtained from our calculations are beneficial to practical applications of these exotic carbon allotropes in optoelectronics and electronics.« less

Epidermodysplasia verruciformis: response to therapy with dialyzable leukocyte extract (transfer factor) derived from household contacts.

PubMed

Vasily, D B; Miller, O F; Fudenberg, H H; Goust, J M; Wilson, G B

1984-05-01

Dialyzable leukocyte extracts (DLE) have been used to treat a variety of antigen selective, and broad spectrum immunodeficiency diseases with sometimes encouraging results. We describe here the clinical and laboratory responses to DLE therapy of 2 patients with epidermodysplasia verruciformis (EV), a chronic cutaneous infection with a variety of human papilloma viruses. One patient with longstanding (30 yr) disease and no improvement to previous therapy showed gradual yet definite resolution of extensive verrucae planae, plaque, tinea-versicolor-like, and tumor lesions scattered over his entire integument. Cessation of DLE therapy for a short time resulted in recurrence of partially regressed lesions and also in the development of new tumors in this patient. The second patient, a grandson of the first patient, with minimal disease showed no progression of the disease during DLE prophylaxis. A third subject (brother of patient number 2) received no DLE and served as a control. All 3 subjects demonstrated severely depressed levels of suppressor T cells, a defect in cell-mediated immunity that has not been hitherto reported in patients with EV. Finally, evidence is presented for a possible X-linked recessive mode of inheritance for susceptibility to EV.

The cosmic ray energy spectrum in the range 1016-1018 eV measured by KASCADE-Grande

NASA Astrophysics Data System (ADS)

Bertaina, M.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

2011-06-01

The KASCADE-Grande experiment, located at Campus North of the Karlsruhe Institute of Technology (Germany) is a multi-component extensive air-shower experiment devoted to the study of cosmic rays and their interactions at primary energies 1014-1018 eV. One of the main goals of the experiment is the measurement of the all particle energy spectrum in the 1016-1018 eV range, i.e. extending the range accessible by KASCADE alone. The Grande detector samples the charged component (Nch) of the air shower while the original KASCADE array provides in addition a measurement of the muon component (Nμ). The combined information of Nch and Nμ is used to estimate the energy on an event-by-event basis and to derive the all-particle energy spectrum. Since the calibration of the observables in terms of the primary energy depends on Monte Carlo simulations, three different methods with partially different sources of uncertainties, have been considered and compared to each other to derive the systematics on the energy spectrum. The different methods employed to derive the spectrum and their uncertainties, as well as the implications of the obtained result, are discussed in detail.

Exosomes and their role in the micro-/macro-environment: a comprehensive review

PubMed Central

Javeed, Naureen; Mukhopadhyay, Debabrata

2017-01-01

The importance of extracellular vesicles (EVs) in cell-cell communication has long been recognized due to their ability to transfer important cellular cargoes such as DNA, mRNA, miRNAs, and proteins to target cells. Compelling evidence supports the role of EVs in the horizontal transfer of cellular material which has the potential to influence normal cellular physiology and promote various disease states. Of the different types of EVs, exosomes have garnered much attention in the past decade due to their abundance in various biological fluids and ability to affect multiple organ systems. The main focus of this review will be on cancer and how cancer-derived exosomes are important mediators of metastasis, angiogenesis, immune modulation, and the tumor macro-/microenvironment. We will also discuss exosomes as potential biomarkers for cancers due to their abundance in biological fluids, ease of uptake, and cellular content. Exosome use in diagnosis, prognosis, and in establishing treatment regimens has enormous potential to revolutionize patient care. PMID:28290182

Exosomes and their role in the micro-/macro-environment: a comprehensive review.

PubMed

Javeed, Naureen; Mukhopadhyay, Debabrata

2017-09-26

The importance of extracellular vesicles (EVs) in cell-cell communication has long been recognized due to their ability to transfer important cellular cargoes such as DNA, mRNA, miRNAs, and proteins to target cells. Compelling evidence supports the role of EVs in the horizontal transfer of cellular material which has the potential to influence normal cellular physiology and promote various disease states. Of the different types of EVs, exosomes have garnered much attention in the past decade due to their abundance in various biological fluids and ability to affect multiple organ systems. The main focus of this review will be on cancer and how cancer-derived exosomes are important mediators of metastasis, angiogenesis, immune modulation, and the tumor macro-/microenvironment. We will also discuss exosomes as potential biomarkers for cancers due to their abundance in biological fluids, ease of uptake, and cellular content. Exosome use in diagnosis, prognosis, and in establishing treatment regimens has enormous potential to revolutionize patient care.

O 1s core levels in Bi2Sr2CaCu2O8+δ single crystals

NASA Astrophysics Data System (ADS)

Parmigiani, F.; Shen, Z. X.; Mitzi, D. B.; Lindau, I.; Spicer, W. E.; Kapitulnik, A.

1991-02-01

High-quality Bi2Sr2CaCu2O8+δ superconducting single crystals, annealed at different oxygen partial pressures, have been studied using angular-resolved x-ray photoelectron spectroscopy with a resolution higher than that used in any previous study. Two states of the oxygen, separated by ~=0.7 eV, are unambiguously observed. Examining these components at different angles makes it possible to distinguish bulk from surface components. Using this capability we discover that annealing under lower oxygen partial pressure (1 atm) results in oxygen intercalation beneath the Bi-O surface layer of the crystal, whereas for higher-pressure anneals (12 atm) additional oxygen is found on the Bi-O surfaces. This steplike intercalation mechanism is also confirmed by the changes observed in the Cu and Bi core lines as a function of the annealing oxygen partial pressure.

Extracellular vesicles and their synthetic analogues in aging and age-associated brain diseases.

PubMed

Smith, J A; Leonardi, T; Huang, B; Iraci, N; Vega, B; Pluchino, S

2015-04-01

Multicellular organisms rely upon diverse and complex intercellular communications networks for a myriad of physiological processes. Disruption of these processes is implicated in the onset and propagation of disease and disorder, including the mechanisms of senescence at both cellular and organismal levels. In recent years, secreted extracellular vesicles (EVs) have been identified as a particularly novel vector by which cell-to-cell communications are enacted. EVs actively and specifically traffic bioactive proteins, nucleic acids, and metabolites between cells at local and systemic levels, modulating cellular responses in a bidirectional manner under both homeostatic and pathological conditions. EVs are being implicated not only in the generic aging process, but also as vehicles of pathology in a number of age-related diseases, including cancer and neurodegenerative and disease. Thus, circulating EVs-or specific EV cargoes-are being utilised as putative biomarkers of disease. On the other hand, EVs, as targeted intercellular shuttles of multipotent bioactive payloads, have demonstrated promising therapeutic properties, which can potentially be modulated and enhanced through cellular engineering. Furthermore, there is considerable interest in employing nanomedicinal approaches to mimic the putative therapeutic properties of EVs by employing synthetic analogues for targeted drug delivery. Herein we describe what is known about the origin and nature of EVs and subsequently review their putative roles in biology and medicine (including the use of synthetic EV analogues), with a particular focus on their role in aging and age-related brain diseases.

Formulation and immunological evaluation of a trivalent vaccine comprising emulsified submicron particles and inactivated virions of H5N1/EV71/JEV

PubMed Central

Lin, Chih-Wei; Chang, Ching-Yun; Chen, Wei-Lin; Lin, Shih-Chang; Liao, Chien-Chun; Chang, Jui-Yuan; Liu, Chia-Chyi; Hu, Alan Yung-Chih; Lu, Tsung-Chun; Chou, Ai-Hsiang; Wu, Suh-Chin; Chong, Pele; Huang, Ming-Hsi

2013-01-01

Combination vaccines can reduce the number of injections and simplify the immunization schedule required to prevent different diseases. Here we assessed the immunogenicity in a mouse model of a vaccine composition comprising inactivated influenza viruses (H5N1/H1N1), enterovirus 71 (EV71), and/or Japanese encephalitis virus (JEV) and investigated whether the vaccine formulations can overcome the immunologic interference between the individual vaccine components. We demonstrated that the antigenic competition happens between H5N1/H1N1 or H5N1/EV71 inactivated virions when the vaccine combinations either formulated with Alum suspensions or without adjuvant. In the presence of PELC emulsified particles, EV71-specific immune responses before and after incorporating H5N1 virus into EV71 vaccine were detected of no significant difference; in addition, H5N1- and EV71-specific immune responses were found at the same level when H5N1/EV71/JEV consolidating into combination vaccine. Emulsified vaccine formulation was represented as a potential tool that is found to reduce the number of injections required to prevent multiple infectious strains causing the same disease (H5N1/H1N1) and/or that protect against different diseases (H5N1/EV71). Combination vaccines can also include a third component to protect against H5N1/EV71/JEV at the same time. PMID:23838466

Effects of Acute Aerobic Exercise on Rats Serum Extracellular Vesicles Diameter, Concentration and Small RNAs Content.

PubMed

Oliveira, Getúlio P; Porto, William F; Palu, Cintia C; Pereira, Lydyane M; Petriz, Bernardo; Almeida, Jeeser A; Viana, Juliane; Filho, Nezio N A; Franco, Octavio L; Pereira, Rinaldo W

2018-01-01

Physical exercise stimulates organs, mainly the skeletal muscle, to release a broad range of molecules, recently dubbed exerkines. Among them, RNAs, such as miRNAs, piRNAs, and tRNAs loaded in extracellular vesicles (EVs) have the potential to play a significant role in the way muscle and other organs communicate to translate exercise into health. Low, moderate and high intensity treadmill protocols were applied to rat groups, aiming to investigate the impact of exercise on serum EVs and their associated small RNA molecules. Transmission electron microscopy, resistive pulse sensing, and western blotting were used to investigate EVs morphology, size distribution, concentration and EVs marker proteins. Small RNA libraries from EVs RNA were sequenced. Exercise did not change EVs size, while increased EVs concentration. Twelve miRNAs were found differentially expressed after exercise: rno-miR-128-3p, 103-3p, 330-5p, 148a-3p, 191a-5p, 10b-5p, 93-5p, 25-3p, 142-5p, 3068-3p, 142-3p, and 410-3p. No piRNA was found differentially expressed, and one tRNA, trna8336, was found down-regulated after exercise. The differentially expressed miRNAs were predicted to target genes involved in the MAPK pathway. A single bout of exercise impacts EVs and their small RNA load, reinforcing the need for a more detailed investigation into EVs and their load as mediators of health-promoting exercise.

Synthesis of Mixed Cu/Ce Oxide Nanoparticles by the Oil-in-Water Microemulsion Reaction Method.

PubMed

Pemartin-Biernath, Kelly; Vela-González, Andrea V; Moreno-Trejo, Maira B; Leyva-Porras, César; Castañeda-Reyna, Iván E; Juárez-Ramírez, Isaías; Solans, Conxita; Sánchez-Domínguez, Margarita

2016-06-16

Cerium oxide and mixed Cu/Ce oxide nanoparticles were prepared by the oil-in-water (O/W) microemulsion reaction method in mild conditions. The Cu/Ce molar ratio was varied between 0/100 and 50/50. According to X-ray diffraction (XRD), below 30/70 Cu/Ce molar ratio, the materials presented a single phase consistent with cubic fluorite CeO₂. However, above Cu/Ce molar ratio 30/70, an excess monoclinic CuO phase in coexistence with the predominant Cu/Ce mixed oxide was detected by XRD and High-Resolution Transmission Electron Microscopy (HRTEM). Raman spectroscopy showed that oxygen vacancies increased significantly as the Cu content was increased. Band gap ( E g ) was investigated as a function of the Cu/Ce molar ratio, resulting in values from 2.91 eV for CeO₂ to 2.32 eV for the mixed oxide with 30/70 Cu/Ce molar ratio. These results indicate that below 30/70 Cu/Ce molar ratio, Cu 2+ is at least partially incorporated into the ceria lattice and very well dispersed in general. In addition, the photodegradation of Indigo Carmine dye under visible light irradiation was explored for selected samples; it was shown that these materials can remove such contaminants, either by adsorption and/or photodegradation. The results obtained will encourage investigation into the optical and photocatalytic properties of these mixed oxides, for widening their potential applications.

Synthesis of Mixed Cu/Ce Oxide Nanoparticles by the Oil-in-Water Microemulsion Reaction Method

PubMed Central

Pemartin-Biernath, Kelly; Vela-González, Andrea V.; Moreno-Trejo, Maira B.; Leyva-Porras, César; Castañeda-Reyna, Iván E.; Juárez-Ramírez, Isaías; Solans, Conxita; Sánchez-Domínguez, Margarita

2016-01-01

Cerium oxide and mixed Cu/Ce oxide nanoparticles were prepared by the oil-in-water (O/W) microemulsion reaction method in mild conditions. The Cu/Ce molar ratio was varied between 0/100 and 50/50. According to X-ray diffraction (XRD), below 30/70 Cu/Ce molar ratio, the materials presented a single phase consistent with cubic fluorite CeO2. However, above Cu/Ce molar ratio 30/70, an excess monoclinic CuO phase in coexistence with the predominant Cu/Ce mixed oxide was detected by XRD and High-Resolution Transmission Electron Microscopy (HRTEM). Raman spectroscopy showed that oxygen vacancies increased significantly as the Cu content was increased. Band gap (Eg) was investigated as a function of the Cu/Ce molar ratio, resulting in values from 2.91 eV for CeO2 to 2.32 eV for the mixed oxide with 30/70 Cu/Ce molar ratio. These results indicate that below 30/70 Cu/Ce molar ratio, Cu2+ is at least partially incorporated into the ceria lattice and very well dispersed in general. In addition, the photodegradation of Indigo Carmine dye under visible light irradiation was explored for selected samples; it was shown that these materials can remove such contaminants, either by adsorption and/or photodegradation. The results obtained will encourage investigation into the optical and photocatalytic properties of these mixed oxides, for widening their potential applications. PMID:28773602

Paper-based Devices for Isolation and Characterization of Extracellular Vesicles

PubMed Central

Chen, Chihchen; Lin, Bo-Ren; Hsu, Min-Yen; Cheng, Chao-Min

2015-01-01

Extracellular vesicles (EVs), membranous particles released from various types of cells, hold a great potential for clinical applications. They contain nucleic acid and protein cargo and are increasingly recognized as a means of intercellular communication utilized by both eukaryote and prokaryote cells. However, due to their small size, current protocols for isolation of EVs are often time consuming, cumbersome, and require large sample volumes and expensive equipment, such as an ultracentrifuge. To address these limitations, we developed a paper-based immunoaffinity platform for separating subgroups of EVs that is easy, efficient, and requires sample volumes as low as 10 μl. Biological samples can be pipetted directly onto paper test zones that have been chemically modified with capture molecules that have high affinity to specific EV surface markers. We validate the assay by using scanning electron microscopy (SEM), paper-based enzyme-linked immunosorbent assays (P-ELISA), and transcriptome analysis. These paper-based devices will enable the study of EVs in the clinic and the research setting to help advance our understanding of EV functions in health and disease. PMID:25867034

Small extracellular vesicles secreted from senescent cells promote cancer cell proliferation through EphA2

PubMed Central

Takasugi, Masaki; Okada, Ryo; Takahashi, Akiko; Virya Chen, David; Watanabe, Sugiko; Hara, Eiji

2017-01-01

Cellular senescence prevents the proliferation of cells at risk for neoplastic transformation. However, the altered secretome of senescent cells can promote the growth of the surrounding cancer cells. Although extracellular vesicles (EVs) have emerged as new players in intercellular communication, their role in the function of senescent cell secretome has been largely unexplored. Here, we show that exosome-like small EVs (sEVs) are important mediators of the pro-tumorigenic function of senescent cells. sEV-associated EphA2 secreted from senescent cells binds to ephrin-A1, that is, highly expressed in several types of cancer cells and promotes cell proliferation through EphA2/ephrin-A1 reverse signalling. sEV sorting of EphA2 is increased in senescent cells because of its enhanced phosphorylation resulting from oxidative inactivation of PTP1B phosphatase. Our results demonstrate a novel mechanism of reactive oxygen species (ROS)-regulated cargo sorting into sEVs, which is critical for the potentially deleterious growth-promoting effect of the senescent cell secretome. PMID:28585531

Dark matter in the universe

NASA Technical Reports Server (NTRS)

Turner, Michael S.

1991-01-01

What is the quantity and composition of material in the Universe? This is one of the most fundamental questions we can ask about the Universe, and its answer bears on a number of important issues including the formation of structure in the Universe, and the ultimate fate and the earliest history of the Universe. Moreover, answering this question could lead to the discovery of new particles, as well as shedding light on the nature of the fundamental interactions. At present, only a partial answer is at hand. Most of the radiation in the Universe does not give off detectable radiation; it is dark. The dark matter associated with bright galaxies contributes somewhere between 10 and 30 percent of the critical density; baryonic matter contributes between 1.1 and 12 percent of the critical. The case for the spatially flat, Einstein-de Sitter model is supported by three compelling theoretical arguments - structure formation, the temporal Copernican principle, and inflation - and by some observational data. If Omega is indeed unity, or even just significantly greater than 0.1, then there is a strong case for a Universe comprised of nonbaryonic matter. There are three well motivated particle dark matter candidates: an axion of mass 10 (exp -6) eV to 10 (exp -4) eV; a neutrino of mass 10 GeV to about 3 TeV; or a neutrino of mass 20 eV to 90 eV. All three possibilities can be tested by experiments that are either planned or are underway.

A DFT study of volatile organic compounds adsorption on transition metal deposited graphene

NASA Astrophysics Data System (ADS)

Kunaseth, Manaschai; Poldorn, Preeyaporn; Junkeaw, Anchalee; Meeprasert, Jittima; Rungnim, Chompoonut; Namuangruk, Supawadee; Kungwan, Nawee; Inntam, Chan; Jungsuttiwong, Siriporn

2017-02-01

Recently, elevated global emission of volatile organic compounds (VOCs) was associated to the acceleration and increasing severity of climate change worldwide. In this work, we investigated the performance of VOCs removal via modified carbon-based adsorbent using density functional theory. Here, four transition metals (TMs) including Pd, Pt, Ag, and Au were deposited onto single-vacancy defective graphene (SDG) surface to increase the adsorption efficiency. Five prototypical VOCs including benzene, furan, pyrrole, pyridine, and thiophene were used to study the adsorption capability of metal-deposited graphene adsorbent. Calculation results revealed that Pd, Pt, Au, and Ag atoms and nanoclusters bind strongly onto the SDG surface. In this study, benzene, furan and pyrrole bind in the π-interaction mode using delocalized π-electron in aromatic ring, while pyridine and thiophene favor X- interaction mode, donating lone pair electron from heteroatom. In terms of adsorption, pyridine VOC adsorption strengths to the TM-cluster doped SDG surfaces are Pt4 (-2.11 eV) > Pd4 (-2.05 eV) > Ag4 (-1.53 eV) > Au4 (-1.87 eV). Our findings indicate that TM-doped SDG is a suitable adsorbent material for VOC removal. In addition, partial density of states analysis suggests that benzene, furan, and pyrrole interactions with TM cluster are based on p-orbitals of carbon atoms, while pyridine and thiophene interactions are facilitated by hybridized sp2-orbitals of heteroatoms. This work provides a key insight into the fundamentals of VOCs adsorption on carbon-based adsorbent.

Forward- and reverse-bias tunneling effects in n/+/p silicon solar cells

NASA Technical Reports Server (NTRS)

Garlick, G. F. J.; Kachare, A. H.

1980-01-01

Excess currents due to field-assisted tunneling in both forward and reverse bias directions have been observed in n(+)-p silicon solar cells. These currents arise from the effect of conducting paths produced in the depletion layer by n(+) diffusion and cell processing. Forward-bias data indicate a small potential barrier with height of 0.04 eV at the n(+) end of conducting paths. Under reverse bias, excess tunneling currents involve a potential barrier at the p end of the conducting paths, the longer paths being associated with smaller barrier heights and dominating at the lower temperatures. Low-reverse-bias data give energy levels of 0.11 eV for lower temperatures (253-293 K) and 0.35 eV for higher temperatures (293-380 K). A model is suggested to explain the results.

Extracellular Vesicles from Bone Marrow‐Derived Mesenchymal Stem Cells Improve Survival from Lethal Hepatic Failure in Mice

PubMed Central

Haga, Hiroaki; Yan, Irene K.; Takahashi, Kenji; Matsuda, Akiko

2017-01-01

Abstract Stem cell‐based therapies have potential for treatment of liver injury by contributing to regenerative responses, through functional tissue replacement or paracrine effects. The release of extracellular vesicles (EV) from cells has been implicated in intercellular communication, and may contribute to beneficial paracrine effects of stem cell‐based therapies. Therapeutic effects of bone‐marrow derived mesenchymal stem cells (MSC) and vesicles released by these cells were examined in a lethal murine model of hepatic failure induced by d‐galactosamine/tumor necrosis factor‐α (TNF‐α). Systemically administered EV derived from MSC accumulated within the injured liver following systemic administration, reduced hepatic injury, and modulated cytokine expression. Moreover, survival was dramatically increased by EV derived from either murine or human MSC. Similar results were observed with the use of cryopreserved mMSC‐EV after 3 months. Y‐RNA‐1 was identified as a highly enriched noncoding RNA within hMSC‐EV compared to cells of origin. Moreover, siRNA mediated knockdown of Y‐RNA‐1 reduced the protective effects of MSC‐EV on TNF‐α/ActD‐mediated hepatocyte apoptosis in vitro. These data support a critical role for MSC‐derived EV in mediating reparative responses following hepatic injury, and provide compelling evidence to support the therapeutic use of MSC‐derived EV in fulminant hepatic failure. Stem Cells Translational Medicine 2017;6:1262–1272 PMID:28213967

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huo, Hong; Cai, Hao; Zhang, Qiang

We evaluated the fuel-cycle emissions of greenhouse gases (GHGs) and air pollutants (NOx, SO2, PM10, and PM2.5) of electric vehicles (EVs) in China and the United States (U.S.), two of the largest potential markets for EVs in the world. Six of the most economically developed and populated regions in China and the U.S. were selected. The results showed that EV fuel-cycle emissions depend substantially on the carbon intensity and cleanness of the electricity mix, and vary significantly across the regions studied. In those regions with a low share of coal-based electricity (e.g., California), EVs can reduce GHG and air pollutantmore » emissions (except for PM) significantly compared with conventional vehicles. However, in the Chinese regions and selected U.S. Midwestern states where coal dominates in the generation mix, EVs can reduce GHG emissions but increase the total and urban emissions of air pollutants. In 2025, EVs will offer greater reductions in GHG and air pollutant emissions because emissions from power plants will be better controlled; EVs in the Chinese regions examined, however, may still increase SO2 and PM emissions. Reductions of 60–85% in GHGs and air pollutants could be achieved were EVs charged with 80% renewable electricity or the electricity generated from the best available technologies of coal-fired power plants, which are futuristic power generation scenarios.« less

The added economic and environmental value of plug-in electric vehicles connected to commercial building microgrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, Michael; Momber, Ilan; Megel, Olivier

2010-08-25

Connection of electric storage technologies to smartgrids or microgrids will have substantial implications for building energy systems. In addition to potentially supplying ancillary services directly to the traditional centralized grid (or macrogrid), local storage will enable demand response. As an economically attractive option, mobile storage devices such as plug-in electric vehicles (EVs) are in direct competition with conventional stationary sources and storage at the building. In general, it is assumed that they can improve the financial as well as environmental attractiveness of renewable and fossil based on-site generation (e.g. PV, fuel cells, or microturbines operating with or without combined heatmore » and power). Also, mobile storage can directly contribute to tariff driven demand response in commercial buildings. In order to examine the impact of mobile storage on building energy costs and carbon dioxide (CO2) emissions, a microgrid/distributed-energy-resources (DER) adoption problem is formulated as a mixed-integer linear program with minimization of annual building energy costs applying CO2 taxes/CO2 pricing schemes. The problem is solved for a representative office building in the San Francisco Bay Area in 2020. By using employees' EVs for energy management, the office building can arbitrage its costs. But since the car battery lifetime is reduced, a business model that also reimburses car owners for the degradation will be required. In general, the link between a microgrid and an electric vehicle can create a win-win situation, wherein the microgrid can reduce utility costs by load shifting while the electric vehicle owner receives revenue that partially offsets his/her expensive mobile storage investment. For the California office building with EVs connected under a business model that distributes benefits, it is found that the economic impact is very limited relative to the costs of mobile storage for the site analyzed, i.e. cost reductions from electric vehicle connections are modest. Nonetheless, this example shows that some economic benefit is created because of avoided demand charges and on-peak energy. The strategy adopted by the office building is to avoid these high on-peak costs by using energy from the mobile storage in the business hours. CO2 emission reduction strategy results indicate that EVs' contribution at the selected office building are minor.« less

Production of EV71 vaccine candidates.

PubMed

Chong, Pele; Hsieh, Shih-Yang; Liu, Chia-Chyi; Chou, Ai-Hsiang; Chang, Jui-Yuan; Wu, Suh-Chin; Liu, Shih-Jen; Chow, Yen-Hung; Su, Ih-Jen; Klein, Michel

2012-12-01

Enterovirus 71 (EV71) is now recognized as an emerging neurotropic virus in Asia and with Coxsackie virus (CV) it is the other major causative agent of hand-foot-mouth diseases (HFMD). Effective medications and/or prophylactic vaccines against HFMD are urgently needed. From a scientific (the feasibility of bioprocess, immunological responses and potency in animal challenge model) and business development (cost of goods) points of view, we in this review address and discuss the pros and cons of different EV71 vaccine candidates that have been produced and evaluated in animal models. Epitope-based synthetic peptide vaccine candidates containing residues 211-225 of VP1 formulated with Freund's adjuvant (CFA/IFA) elicited low EV71 virus neutralizing antibody responses, but were protective in the suckling mouse challenge model. Among recombinant EV71 subunits (rVP1, rVP2 and rVP3) expressed in E. coli, purified and formulated with CFA/IFA, only VP1 elicited mouse antibody responses with measurable EV71-specific virus neutralization titers. Immunization of mice with either a DNA plasmid containing VP1 gene or VP1 expressed in Salmonella typhimurium also generated neutralizing antibody responses and protected animals against a live EV71 challenge. Recombinant EV71 virus-like particles (rVLP) produced from baculovirus formulated either with CFA/IFA or alum elicited good virus neutralization titers in both mice and non-human primates, and were found to be protective in the suckling mouse EV71 challenge model. Synthetic peptides or recombinant EV71 subunit vaccines (rVP1 and rVLP) formulated in alum were found to be poorly immunogenic in rabbits. Only formalin-inactivated (FI) EV71 virions formulated in alum elicited cross-neutralizing antibodies against different EV71 genotypes in mice, rabbits and non-human primates but induced weak neutralizing responses against CAV16. From a regulatory, economic and market acceptability standpoint, FI-EV71 virion vaccines are the most promising candidates and are currently being evaluated in human clinical trials. We further describe and analyze some new bioprocesses technologies that have great potential applications in EV71 vaccine development. This review also demonstrates the opportunities and challenges that the Asian vaccine industry faces today.

Flow cytometric analysis of extracellular vesicle subsets in plasma: impact of swarm by particles of non-interest.

PubMed

Libregts, S F W M; Arkesteijn, G J A; Németh, A; Nolte-'t Hoen, E N M; Wauben, M H M

2018-05-20

Essentials Extracellular vesicles (EVs) in biological fluids are promising biomarkers for disease. Fluorescence-based flow cytometric analysis is suitable to detect low abundant EV subsets. Particles of non-interest can induce false-positive light scatter and fluorescent signals. Interference of particles of non-interest can be monitored by analyzing serial dilutions. Background Extracellular vesicles (EVs) in plasma are increasingly being recognized as potential biomarkers. EV analysis for diagnostic purposes should be robust and should allow analysis of EV subsets with a wide range of abundance and in a large number of patient samples. Flow cytometry offers possibilities to meet these criteria, as it allows multiparameter analysis of individual EVs. However, analysis of plasma EVs is challenging, because of their size and heterogeneity, and the presence of other submicrometer-sized particles in plasma that could interfere with EV analysis. Objectives To explore whether fluorescence-based flow cytometric analysis of EV subsets is suitable when the EVs of interest are present in low abundance in a background of non-labeled or differently labeled EVs and particles. Methods Fluorescently labeled EVs of interest were spiked at different ratios in full plasma, purified plasma components, or (non-)fluorescent polystyrene beads, and subsequently analyzed by flow cytometry with fluorescence threshold triggering. Results We found that light scatter detection of low-abundance or rare EV subsets during fluorescence threshold triggering was severely affected by particles of non-interest, owing to coincidence and swarming. Importantly, we show that interfering particles labeled with different fluorophores induced false-positive fluorescent signals on the particles of interest. These unwanted effects could only be discerned and controlled by performing serial dilutions and analyzing light scatter and fluorescence parameters. Conclusions We demonstrate how particles of non-interest in plasma can impact on the light scatter and fluorescence detection of low-abundance EVs of interest during fluorescence-based flow cytometric analysis, and provide a means to prevent erroneous data interpretation. © 2018 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.

Immunodominant IgM and IgG Epitopes Recognized by Antibodies Induced in Enterovirus A71-Associated Hand, Foot and Mouth Disease Patients

PubMed Central

Aw-Yong, Kam Leng; Sam, I-Ching; Koh, Mia Tuang

2016-01-01

Enterovirus A71 (EV-A71) is one of the main causative agents of hand, foot and mouth disease (HFMD). Unlike other enteroviruses that cause HFMD, EV-A71 is more frequently associated with severe neurological complications and fatality. To date, no effective licensed antivirals are available to combat EV-A71 infection. Little is known about the immunogenicity of viral non-structural proteins in humans. Previous studies have mainly focused on characterization of epitopes of EV-A71 structural proteins by using immunized animal antisera. In this study, we have characterized human antibody responses against the structural and non-structural proteins of EV-A71. Each viral protein was cloned and expressed in either bacterial or mammalian systems, and tested with antisera by western blot. Results revealed that all structural proteins (VP1-4), and non-structural proteins 2A, 3C and 3D were targets of EV-A71 IgM, whereas EV-A71 IgG recognized all the structural and non-structural proteins. Sixty three synthetic peptides predicted to be immunogenic in silico were synthesized and used for the characterization of EV-A71 linear B-cell epitopes. In total, we identified 22 IgM and four IgG dominant epitopes. Synthetic peptide PEP27, corresponding to residues 142–156 of VP1, was identified as the EV-A71 IgM-specific immunodominant epitope. PEP23, mapped to VP1 41–55, was recognized as the EV-A71 IgG cross-reactive immunodominant epitope. The structural protein VP1 is the major immunodominant site targeted by anti-EV-A71 IgM and IgG antibodies, but epitopes against non-structural proteins were also detected. These data provide new understanding of the immune response to EV-A71 infection, which benefits the development of diagnostic tools, potential therapeutics and subunit vaccine candidates. PMID:27806091

A potential half-Heusler thermoelectric material ScAuSn: A first principle study

NASA Astrophysics Data System (ADS)

Joshi, H.; Rai, D. P.; Thapa, R. K.

2018-04-01

Density Functional Theory along with semi classical Boltzmann transport theory have been applied to study the electronic and thermoelectric property of the Heusler alloy ScAuSn. It has been found that ScAuSn is an indirect band gap semiconductor with a gap of 0.344 eV. The thermoelectric properties such as electrical conductivity (σ), Seebeck coefficient (S), electronic thermal conductivity (κ) etc. are reported as a function of chemical potential in the region ± 2.0 eV, with respect to constant temperature. The calculated ZT value is almost equal to 1, thus making ScAuSn a potential thermoelectric candidate.

Extracellular Vesicles: Role in Inflammatory Responses and Potential Uses in Vaccination in Cancer and Infectious Diseases.

PubMed

Campos, João Henrique; Soares, Rodrigo Pedro; Ribeiro, Kleber; Andrade, André Cronemberger; Batista, Wagner Luiz; Torrecilhas, Ana Claudia

2015-01-01

Almost all cells and organisms release membrane structures containing proteins, lipids, and nucleic acids called extracellular vesicles (EVs), which have a wide range of functions concerning intercellular communication and signaling events. Recently, the characterization and understanding of their biological role have become a main research area due to their potential role in vaccination, as biomarkers antigens, early diagnostic tools, and therapeutic applications. Here, we will overview the recent advances and studies of Evs shed by tumor cells, bacteria, parasites, and fungi, focusing on their inflammatory role and their potential use in vaccination and diagnostic of cancer and infectious diseases.

Extracellular Vesicles: Role in Inflammatory Responses and Potential Uses in Vaccination in Cancer and Infectious Diseases

PubMed Central

Campos, João Henrique; Soares, Rodrigo Pedro; Ribeiro, Kleber; Cronemberger Andrade, André; Batista, Wagner Luiz; Torrecilhas, Ana Claudia

2015-01-01

Almost all cells and organisms release membrane structures containing proteins, lipids, and nucleic acids called extracellular vesicles (EVs), which have a wide range of functions concerning intercellular communication and signaling events. Recently, the characterization and understanding of their biological role have become a main research area due to their potential role in vaccination, as biomarkers antigens, early diagnostic tools, and therapeutic applications. Here, we will overview the recent advances and studies of Evs shed by tumor cells, bacteria, parasites, and fungi, focusing on their inflammatory role and their potential use in vaccination and diagnostic of cancer and infectious diseases. PMID:26380326

Cancer-associated fibroblast-derived annexin A6+ extracellular vesicles support pancreatic cancer aggressiveness

PubMed Central

Leca, Julie; Martinez, Sébastien; Lac, Sophie; Nigri, Jérémy; Secq, Véronique; Rubis, Marion; Bressy, Christian; Lavaut, Marie-Noelle; Dusetti, Nelson; Loncle, Céline; Roques, Julie; Pietrasz, Daniel; Bousquet, Corinne; Garcia, Stéphane; Granjeaud, Samuel; Ouaissi, Mehdi; Bachet, Jean Baptiste; Iovanna, Juan L.; Zimmermann, Pascale; Vasseur, Sophie

2016-01-01

The intratumoral microenvironment, or stroma, is of major importance in the pathobiology of pancreatic ductal adenocarcinoma (PDA), and specific conditions in the stroma may promote increased cancer aggressiveness. We hypothesized that this heterogeneous and evolving compartment drastically influences tumor cell abilities, which in turn influences PDA aggressiveness through crosstalk that is mediated by extracellular vesicles (EVs). Here, we have analyzed the PDA proteomic stromal signature and identified a contribution of the annexin A6/LDL receptor-related protein 1/thrombospondin 1 (ANXA6/LRP1/TSP1) complex in tumor cell crosstalk. Formation of the ANXA6/LRP1/TSP1 complex was restricted to cancer-associated fibroblasts (CAFs) and required physiopathologic culture conditions that improved tumor cell survival and migration. Increased PDA aggressiveness was dependent on tumor cell–mediated uptake of CAF-derived ANXA6+ EVs carrying the ANXA6/LRP1/TSP1 complex. Depletion of ANXA6 in CAFs impaired complex formation and subsequently impaired PDA and metastasis occurrence, while injection of CAF-derived ANXA6+ EVs enhanced tumorigenesis. We found that the presence of ANXA6+ EVs in serum was restricted to PDA patients and represents a potential biomarker for PDA grade. These findings suggest that CAF–tumor cell crosstalk supported by ANXA6+ EVs is predictive of PDA aggressiveness, highlighting a therapeutic target and potential biomarker for PDA. PMID:27701147

78 FR 54635 - Notice of Intent To Prepare an Environmental Impact Statement for EA-18G Growler Airfield...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... the potential environmental effects associated with the introduction of two additional EA-18G Growler... CONTACT: EA-18G EIS Project Manager (Code EV21/ SS); Naval Facilities Engineering Command (NAVFAC... request should be submitted to: EA-18G EIS Project Manager (Code EV21/SS); Naval Facilities Engineering...

The partial fission of fast spinning asteroids

NASA Astrophysics Data System (ADS)

Tardivel, Simon; Sanchez, Paul; Scheeres, Daniel J.

2016-10-01

The spin rates of asteroids systematically change over time due the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. Above a certain spin rate that depends on the body's density, regions of an asteroid can enter in tension, with components held to the body by cohesive forces. When the body fails, deformation or fission can occur. Catastrophic fission leading to complete disruption has been directly observed in active asteroid P/2013 R3. Partial fission, the loss of only part of the body, has been proposed as a mechanism for the formation of binaries and is explored here.The equatorial cavities of (341843) 2008 EV5 and of (185851) 2000 DP107 (a binary system) are consistent with a localized partial fission of the body (LPSC 2016 #1036). The examination of the gravity field of these bodies reveals that a mass placed within these cavities could be shed. In this mechanism, the outward pull of inertial forces creates an average stress at the cavity interface of ≈1 Pa for 2008 EV5 and ≈3 Pa for 2000 DP107 at spin periods of ≈3.15 h for the assumed densities of 1.3 g/cm3.This work continues the study of this partial, localized fission. Specifically, it addresses the issue of the low cohesion necessary to the mechanism. These cohesion values are typically lower than global strength values inferred on other asteroids (10 - 200 Pa), meaning that partial fission may occur prior to larger-scale deformations. Yet, several processes can explain the discrepancy, as they can naturally segregate particles by size. For instance, landslides or granular convection (Brazil nut effect) could bring larger boulders to the equator of the body, while finer particles are left at higher latitudes or sink to the center. Conversely, failure of the interior could bring boulders to the surface. The peculiar profile shape of these asteroids, shared by many binaries (e.g. 1999 KW4, 1996 FG3) may also be a clue of this heterogeneity, as this "spin top" shape is obtained in simulations with a weak shell and a strong core.Using observations and simulations, we consider these processes and the role that this partial fission mechanism could play in the formation of binary asteroids and the creation of equatorial divots on asteroids.

The Role of Work Function and Band Gap in Resistive Switching Behaviour of ZnTe Thin Films

NASA Astrophysics Data System (ADS)

Rowtu, Srinu; Sangani, L. D. Varma; Krishna, M. Ghanashyam

2018-02-01

Resistive switching behavior by engineering the electrode work function and band gap of ZnTe thin films is demonstrated. The device structures Au/ZnTe/Au, Au/ZnTe/Ag, Al/ZnTe/Ag and Pt/ZnTe/Ag were fabricated. ZnTe was deposited by thermal evaporation and the stoichiometry and band gap were controlled by varying the source-substrate distance. Band gap could be varied between 1.0 eV to approximately 4.0 eV with the larger band gap being attributed to the partial oxidation of ZnTe. The transport characteristics reveal that the low-resistance state is ohmic in nature which makes a transition to Poole-Frenkel defect-mediated conductivity in the high-resistance states. The highest R off-to- R on ratio achieved is 109. Interestingly, depending on stoichiometry, both unipolar and bipolar switching can be realized.

Growth and band gap of the filled tetrahedral semiconductor LiMgN

NASA Astrophysics Data System (ADS)

Kuriyama, K.; Nagasawa, K.; Kushida, K.

2002-04-01

The cubic AlN-like compound, LiMgN, can be considered as a zinc blende-like (MgN) - lattice partially filled with He-like Li + interstitials. LiMgN was synthesized by direct reaction between N 2 and LiMg alloy at around 800°C for 8 h. Polycrystalline crystals are grown as cornflake-like shapes with a light yellow color and show the LiMgN-phase (the lattice constant a=4.955±0.005 Å) except for non-reactant LiMg and oxide (LiNO 3). The ordered structure between Li and Mg is not confirmed exactly by X-ray diffraction studies. The band gap of as-grown crystals evaluated using photoacoustic spectroscopy is 3.2 eV, which value is supported by an optical transmission spectrum. The band gap value of LiMgN is close to that of GaN (zinc blende, Eg=3.45 eV).

First-Principles Estimation of Electronic Temperature from X-Ray Thomson Scattering Spectrum of Isochorically Heated Warm Dense Matter

NASA Astrophysics Data System (ADS)

Mo, Chongjie; Fu, Zhenguo; Kang, Wei; Zhang, Ping; He, X. T.

2018-05-01

Through the perturbation formula of time-dependent density functional theory broadly employed in the calculation of solids, we provide a first-principles calculation of x-ray Thomson scattering spectrum of isochorically heated aluminum foil, as considered in the experiments of Sperling et al. [Phys. Rev. Lett. 115, 115001 (2015), 10.1103/PhysRevLett.115.115001], where ions were constrained near their lattice positions. From the calculated spectra, we find that the electronic temperature cannot exceed 2 eV, much smaller than the previous estimation of 6 eV via the detailed balance relation. Our results may well be an indication of unique electronic properties of warm dense matter, which can be further illustrated by future experiments. The lower electronic temperature predicted partially relieves the concern on the heating of x-ray free electron laser to the sample when used in structure measurement.

Study of GaN nanorods converted from β-Ga2O3

NASA Astrophysics Data System (ADS)

Li, Yuewen; Xiong, Zening; Zhang, Dongdong; Xiu, Xiangqian; Liu, Duo; Wang, Shuang; Hua, Xuemei; Xie, Zili; Tao, Tao; Liu, Bin; Chen, Peng; Zhang, Rong; Zheng, Youdou

2018-05-01

We report here high-quality β-Ga2O3 nanorods (NRs) grown on sapphire substrates by hydrothermal method. Ammoniating the β-Ga2O3 NRs results in strain-free wurtzite gallium nitride (GaN) NRs. It was shown by XRD and Raman spectroscopy that β-Ga2O3 was partially converted to GaN/β-Ga2O3 at 1000 °C and then completely converted to GaN NRs at 1050 °C, as confirmed by high-resolution transmission electron microscopy (HRTEM). There is no band-edge emission of β-Ga2O3 in the cathodoluminescence spectrum, and only a deep-level broad emission observed at 3.68-3.73 eV. The band edge emission (3.39 eV) of GaN NRs converted from β-Ga2O3 can also be observed.

An ab initio study on BeX 3- superhalogen anions (X = F, Cl, Br)

NASA Astrophysics Data System (ADS)

Anusiewicz, Iwona; Skurski, Piotr

2002-06-01

The vertical electron detachment energies (VDE) of 10 BeX 3- (X = F, Cl, Br) anions were calculated at the outer valence Green function (OVGF) level with the 6-311++G(3df) basis sets. The largest vertical electron binding energy was found for BeF 3- system (7.63 eV). All negatively charged species possess the vertical electron detachment energies that are larger than 5.5 eV and thus may be termed superhalogen anions. The strong dependence of the VDE of the BeX 3- species on the ligand-central atom (Be-X) distance and on the partial atomic charge localized on Be was observed and discussed, as well as the other factors that may influence the electronic stability of such anions. In addition, the usefulness of the various theoretical treatments for estimating the VDEs of superhalogen anions was tested and analyzed.

Current and future greenhouse gas emissions associated with electricity generation in China: implications for electric vehicles.

PubMed

Shen, Wei; Han, Weijian; Wallington, Timothy J

2014-06-17

China's oil imports and greenhouse gas (GHG) emissions have grown rapidly over the past decade. Addressing energy security and GHG emissions is a national priority. Replacing conventional vehicles with electric vehicles (EVs) offers a potential solution to both issues. While the reduction in petroleum use and hence the energy security benefits of switching to EVs are obvious, the GHG benefits are less obvious. We examine the current Chinese electric grid and its evolution and discuss the implications for EVs. China's electric grid will be dominated by coal for the next few decades. In 2015 in Beijing, Shanghai, and Guangzhou, EVs will need to use less than 14, 19, and 23 kWh/100 km, respectively, to match the 183 gCO2/km WTW emissions for energy saving vehicles. In 2020, in Beijing, Shanghai, and Guangzhou EVs will need to use less than 13, 18, and 20 kWh/100 km, respectively, to match the 137 gCO2/km WTW emissions for energy saving vehicles. EVs currently demonstrated in China use 24-32 kWh/100 km. Electrification will reduce petroleum imports; however, it will be very challenging for EVs to contribute to government targets for GHGs emissions reduction.

Differential and transferable modulatory effects of mesenchymal stromal cell-derived extracellular vesicles on T, B and NK cell functions

PubMed Central

Di Trapani, Mariano; Bassi, Giulio; Midolo, Martina; Gatti, Alessandro; Kamga, Paul Takam; Cassaro, Adriana; Carusone, Roberta; Adamo, Annalisa; Krampera, Mauro

2016-01-01

Mesenchymal stromal cells (MSCs) are multipotent cells, immunomodulatory stem cells that are currently used for regenerative medicine and treatment of a number of inflammatory diseases, thanks to their ability to significantly influence tissue microenvironments through the secretion of large variety of soluble factors. Recently, several groups have reported the presence of extracellular vesicles (EVs) within MSC secretoma, showing their beneficial effect in different animal models of disease. Here, we used a standardized methodological approach to dissect the immunomodulatory effects exerted by MSC-derived EVs on unfractionated peripheral blood mononuclear cells and purified T, B and NK cells. We describe here for the first time: i. direct correlation between the degree of EV-mediated immunosuppression and EV uptake by immune effector cells, a phenomenon further amplified following MSC priming with inflammatory cytokines; ii. induction in resting MSCs of immunosuppressive properties towards T cell proliferation through EVs obtained from primed MSCs, without any direct inhibitory effect towards T cell division. Our conclusion is that the use of reproducible and validated assays is not only useful to characterize the mechanisms of action of MSC-derived EVs, but is also capable of justifying EV potential use as alternative cell-free therapy for the treatment of human inflammatory diseases. PMID:27071676

Differential and transferable modulatory effects of mesenchymal stromal cell-derived extracellular vesicles on T, B and NK cell functions.

PubMed

Di Trapani, Mariano; Bassi, Giulio; Midolo, Martina; Gatti, Alessandro; Kamga, Paul Takam; Cassaro, Adriana; Carusone, Roberta; Adamo, Annalisa; Krampera, Mauro

2016-04-13

Mesenchymal stromal cells (MSCs) are multipotent cells, immunomodulatory stem cells that are currently used for regenerative medicine and treatment of a number of inflammatory diseases, thanks to their ability to significantly influence tissue microenvironments through the secretion of large variety of soluble factors. Recently, several groups have reported the presence of extracellular vesicles (EVs) within MSC secretoma, showing their beneficial effect in different animal models of disease. Here, we used a standardized methodological approach to dissect the immunomodulatory effects exerted by MSC-derived EVs on unfractionated peripheral blood mononuclear cells and purified T, B and NK cells. We describe here for the first time: i. direct correlation between the degree of EV-mediated immunosuppression and EV uptake by immune effector cells, a phenomenon further amplified following MSC priming with inflammatory cytokines; ii. induction in resting MSCs of immunosuppressive properties towards T cell proliferation through EVs obtained from primed MSCs, without any direct inhibitory effect towards T cell division. Our conclusion is that the use of reproducible and validated assays is not only useful to characterize the mechanisms of action of MSC-derived EVs, but is also capable of justifying EV potential use as alternative cell-free therapy for the treatment of human inflammatory diseases.

Manufacturing of Human Extracellular Vesicle-Based Therapeutics for Clinical Use

PubMed Central

Gimona, Mario; Pachler, Karin; Laner-Plamberger, Sandra; Schallmoser, Katharina; Rohde, Eva

2017-01-01

Extracellular vesicles (EVs) derived from stem and progenitor cells may have therapeutic effects comparable to their parental cells and are considered promising agents for the treatment of a variety of diseases. To this end, strategies must be designed to successfully translate EV research and to develop safe and efficacious therapies, whilst taking into account the applicable regulations. Here, we discuss the requirements for manufacturing, safety, and efficacy testing of EVs along their path from the laboratory to the patient. Development of EV-therapeutics is influenced by the source cell types and the target diseases. In this article, we express our view based on our experience in manufacturing biological therapeutics for routine use or clinical testing, and focus on strategies for advancing mesenchymal stromal cell (MSC)-derived EV-based therapies. We also discuss the rationale for testing MSC-EVs in selected diseases with an unmet clinical need such as critical size bone defects, epidermolysis bullosa and spinal cord injury. While the scientific community, pharmaceutical companies and clinicians are at the point of entering into clinical trials for testing the therapeutic potential of various EV-based products, the identification of the mode of action underlying the suggested potency in each therapeutic approach remains a major challenge to the translational path. PMID:28587212

Manufacturing of Human Extracellular Vesicle-Based Therapeutics for Clinical Use.

PubMed

Gimona, Mario; Pachler, Karin; Laner-Plamberger, Sandra; Schallmoser, Katharina; Rohde, Eva

2017-06-03

Extracellular vesicles (EVs) derived from stem and progenitor cells may have therapeutic effects comparable to their parental cells and are considered promising agents for the treatment of a variety of diseases. To this end, strategies must be designed to successfully translate EV research and to develop safe and efficacious therapies, whilst taking into account the applicable regulations. Here, we discuss the requirements for manufacturing, safety, and efficacy testing of EVs along their path from the laboratory to the patient. Development of EV-therapeutics is influenced by the source cell types and the target diseases. In this article, we express our view based on our experience in manufacturing biological therapeutics for routine use or clinical testing, and focus on strategies for advancing mesenchymal stromal cell (MSC)-derived EV-based therapies. We also discuss the rationale for testing MSC-EVs in selected diseases with an unmet clinical need such as critical size bone defects, epidermolysis bullosa and spinal cord injury. While the scientific community, pharmaceutical companies and clinicians are at the point of entering into clinical trials for testing the therapeutic potential of various EV-based products, the identification of the mode of action underlying the suggested potency in each therapeutic approach remains a major challenge to the translational path.

Extracellular vesicles released from mesenchymal stromal cells stimulate bone growth in osteogenesis imperfecta.

PubMed

Otsuru, Satoru; Desbourdes, Laura; Guess, Adam J; Hofmann, Ted J; Relation, Theresa; Kaito, Takashi; Dominici, Massimo; Iwamoto, Masahiro; Horwitz, Edwin M

2018-01-01

Systemic infusion of mesenchymal stromal cells (MSCs) has been shown to induce acute acceleration of growth velocity in children with osteogenesis imperfecta (OI) despite minimal engraftment of infused MSCs in bones. Using an animal model of OI we have previously shown that MSC infusion stimulates chondrocyte proliferation in the growth plate and that this enhanced proliferation is also observed with infusion of MSC conditioned medium in lieu of MSCs, suggesting that bone growth is due to trophic effects of MSCs. Here we sought to identify the trophic factor secreted by MSCs that mediates this therapeutic activity. To examine whether extracellular vesicles (EVs) released from MSCs have therapeutic activity, EVs were isolated from MSC conditioned medium by ultracentrifugation. To further characterize the trophic factor, RNA or microRNA (miRNA) within EVs was depleted by either ribonuclease (RNase) treatment or suppressing miRNA biogenesis in MSCs. The functional activity of these modified EVs was evaluated using an in vitro chondrocyte proliferation assay. Finally, bone growth was evaluated in an animal model of OI treated with EVs. We found that infusion of MSC-derived EVs stimulated chondrocyte proliferation in the growth plate, resulting in improved bone growth in a mouse model of OI. However, infusion of neither RNase-treated EVs nor miRNA-depleted EVs enhanced chondrocyte proliferation. MSCs exert therapeutic effects in OI by secreting EVs containing miRNA, and EV therapy has the potential to become a novel cell-free therapy for OI that will overcome some of the current limitations in MSC therapy. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

The compatibility of inactivated-Enterovirus 71 vaccination with Coxsackievirus A16 and Poliovirus immunizations in humans and animals

PubMed Central

Mao, Qunying; Wang, Yiping; Shao, Jie; Ying, Zhifang; Gao, Fan; Yao, Xin; Li, Changgui; Ye, Qiang; Xu, Miao; Li, Rongcheng; Zhu, Fengcai; Liang, Zhenglun

2015-01-01

Enterovirus 71 (EV71) is the key pathogen for Hand, Foot, and Mouth Disease (HFMD) and can result in severe neurological complications and death among young children. Three inactivated-EV71 vaccines have gone through phase III clinical trials and have demonstrated good safety and efficacy. These vaccines will benefit young children under the threat of severe HFMD. However, the potential immunization-related compatibility for different enterovirus vaccines remains unclear, making it hard to include the EV71 vaccine in Expanded Program on Immunization (EPI). Here, we measured the neutralizing antibodies (NTAbs) against EV71, Coxsackievirus A16 (CA16) and Poliovirus from infants enrolled in those EV71 vaccine clinical trials. The results indicated that the levels of NTAb GMTs for EV71 increased significantly in all 3 vaccine groups (high, middle and low dosages, respectively) post-vaccination. Seroconversion ratios and Geometric mean fold increase were significantly higher in the vaccine groups (≥7/9 and 8.9～228.1) than in the placebo group (≤1/10 and 0.8～1.7, P < 0.05). But no similar NTAb response trends were found in CA16 and 3 types of Poliovirus. The decrease of 3 types of Poliovirus NTAb GMTs and an increase of CA16 GMTs post-EV71-vaccination were found in vaccine and placebo groups. Further animal study on CA16 and poliovirus vaccine co-immunization or pre-immunization with EV71 vaccine in mice indicated that there was no NTAb cross-activity between EV71 and CA16/Poliovirus. Our research showed that inactivated-EV71 vaccine has good specific-neutralizing capacity and can be included in EPI. PMID:25715318

Rotational and vibrational transitions for Li + H2 collisions

NASA Technical Reports Server (NTRS)

Choi, B. H.; Poe, R. T.; Tang, K. T.

1977-01-01

Close coupling calculations for integral and differential cross sections have been carried out for Li + H2 collisions with an ab initio Hartree-Fock potential energy surface. Rotational, vibrational, and vib-rotational excitation cross sections are reported at 0.4336 eV, 0.7 eV, and 0.8673 eV in the center of mass system. For pure rotational excitations, which dominate the inelastic scattering, coupling with vibrational states is not very important. For vibrational transitions, the influence of large multiquantum rotational transitions is far less than that found for Li(+) + H2 collisions.

Ion acceleration and non-Maxwellian electron distributions in a low collisionality, high power helicon plasma source

NASA Astrophysics Data System (ADS)

Li, Yan; Sung, Yung-Ta; Scharer, John

2015-11-01

Ion acceleration through plasma double layer and non-Maxwellian two temperature electron distributions have been observed in Madison Helicon Experiment (MadHeX) operated in high RF power (>1000 W) and low Ar pressure (0.17 mtorr) inductive mode. By applying Optical Emission Spectroscopy (OES) cross-checked with an RF-compensated Langmuir probe (at 13.56 MHz and its second and third harmonics), the fast (>80 eV), untrapped electrons downstream of the double layer have a higher temperature of 13 eV than the trapped bulk electrons upstream with a temperature of 4 eV. The reduction of plasma potential and density observed in the double layer region require an upstream temperature ten times the measured 4 eV if occurring via Boltzmann ambipolar expansion. The hot tail electrons of the non-Maxwellian electron distribution affect the formation and the potential drop of the double layer region. The mechanism behind this has been explored via several non-invasive plasma diagnostics tools. The OES measured electron temperatures and densities are also cross-checked with Atomic Data and Analysis Structure (ADAS) and a millimeter wave interferometer respectively. The IEDF is measured by a four-grid RPA and also cross-checked with argon 668 nm Laser Induced Fluorescence (LIF). An emissive probe has been used to measure the plasma potential.

Isolation and characterization of a new enterovirus F in yak feces in the Qinghai-Tibetan Plateau.

PubMed

He, Huan; Tang, Cheng; Chen, Xinnuo; Yue, Hua; Ren, Yupeng; Liu, Yan; Zhang, Bin

2017-02-01

An enterovirus (EV) strain, designated as SWUN-AB001, was isolated in the Qinghai-Tibetan Plateau from a yak with severe diarrheal disease. The complete genome of strain SWUN-AB001 was 7,382 bp in length and shared 35.1-68.5% nt identities with bovine EVs belonging to a candidate new type EV-F7. Using the sequence difference values in the VP1 gene as a criterion for demarcating a new serotype/genotype in the Enterovirus genus, strain SWUN-AB001 had only a 71.1% nt and a 79.2% aa identity, in the VP1 region, with the most closely matched EV, further indicating that a new type of EV had been identified. Phylogenetic analysis of the nt sequence of the viral polyprotein and of VP1 genes demonstrated that the virus fell within the EV-F cluster, but was located in a unique lineage. Furthermore, a large-scale surveillance study indicated that the prevalence of this EV in yaks was 31.05% (95% CI = 25.5-37.6%) in 235 animals with diarrhea and 24.13% (95% CI = 17.4-32.4%) in 116 healthy yaks. However, there was no significant difference in virus prevalence between diarrheal and healthy samples. Interestingly, in the Tibet region, diarrheal feces had a higher incidence of EVs than feces of healthy yaks (odd ratios = 6.03, 95% CI = 1.93-18.86), indicating that the incidence of EV was potentially correlated with the clinical symptom of diarrhea in yaks.

Technology Status and Expected Greenhouse Gas Emissions of Battery, Plug-In Hybrid, and Fuel Cell Electric Vehicles

NASA Astrophysics Data System (ADS)

Lipman, Timothy E.

2011-11-01

Electric vehicles (EVs) of various types are experiencing a commercial renaissance but of uncertain ultimate success. Many new electric-drive models are being introduced by different automakers with significant technical improvements from earlier models, particularly with regard to further refinement of drivetrain systems and important improvements in battery and fuel cell systems. The various types of hybrid and all-electric vehicles can offer significant greenhouse gas (GHG) reductions when compared to conventional vehicles on a full fuel-cycle basis. In fact, most EVs used under most condition are expected to significantly reduce lifecycle GHG emissions. This paper reviews the current technology status of EVs and compares various estimates of their potential to reduce GHGs on a fuel cycle basis. In general, various studies show that battery powered EVs reduce GHGs by a widely disparate amount depending on the type of powerplant used and the particular region involved, among other factors. Reductions typical of the United States would be on the order of 20-50%, depending on the relative level of coal versus natural gas and renewables in the powerplant feedstock mix. However, much deeper reductions of over 90% are possible for battery EVs running on renewable or nuclear power sources. Plug-in hybrid vehicles running on gasoline can reduce emissions by 20-60%, and fuel cell EV reduce GHGs by 30-50% when running on natural gas-derived hydrogen and up to 95% or more when the hydrogen is made (and potentially compressed) using renewable feedstocks. These are all in comparison to what is usually assumed to be a more advanced gasoline vehicle "baseline" of comparison, with some incremental improvements by 2020 or 2030. Thus, the emissions from all of these EV types are highly variable depending on the details of how the electric fuel or hydrogen is produced.

Circulating Extracellular Vesicles with Specific Proteome and Liver MicroRNAs Are Potential Biomarkers for Liver Injury in Experimental Fatty Liver Disease

PubMed Central

Povero, Davide; Eguchi, Akiko; Li, Hongying; Johnson, Casey D.; Papouchado, Bettina G.; Wree, Alexander; Messer, Karen; Feldstein, Ariel E.

2014-01-01

Background & Aim Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in both adult and children. Currently there are no reliable methods to determine disease severity, monitor disease progression, or efficacy of therapy, other than an invasive liver biopsy. Design Choline Deficient L-Amino Acid (CDAA) and high fat diets were used as physiologically relevant mouse models of NAFLD. Circulating extracellular vesicles were isolated, fully characterized by proteomics and molecular analyses and compared to control groups. Liver-related microRNAs were isolated from purified extracellular vesicles and liver specimens. Results We observed statistically significant differences in the level of extracellular vesicles (EVs) in liver and blood between two control groups and NAFLD animals. Time-course studies showed that EV levels increase early during disease development and reflect changes in liver histolopathology. EV levels correlated with hepatocyte cell death (r2 = 0.64, p<0.05), fibrosis (r2 = 0.66, p<0.05) and pathological angiogenesis (r2 = 0.71, p<0.05). Extensive characterization of blood EVs identified both microparticles (MPs) and exosomes (EXO) present in blood of NAFLD animals. Proteomic analysis of blood EVs detected various differentially expressed proteins in NAFLD versus control animals. Moreover, unsupervised hierarchical clustering identified a signature that allowed for discrimination between NAFLD and controls. Finally, the liver appears to be an important source of circulating EVs in NAFLD animals as evidenced by the enrichment in blood with miR-122 and 192 - two microRNAs previously described in chronic liver diseases, coupled with a corresponding decrease in expression of these microRNAs in the liver. Conclusions These findings suggest a potential for using specific circulating EVs as sensitive and specific biomarkers for the noninvasive diagnosis and monitoring of NAFLD. PMID:25470250

Effects of oxygen partial pressure on Li-air battery performance

NASA Astrophysics Data System (ADS)

Kwon, Hyuk Jae; Lee, Heung Chan; Ko, Jeongsik; Jung, In Sun; Lee, Hyun Chul; Lee, Hyunpyo; Kim, Mokwon; Lee, Dong Joon; Kim, Hyunjin; Kim, Tae Young; Im, Dongmin

2017-10-01

For application in electric vehicles (EVs), the Li-air battery system needs an air intake system to supply dry oxygen at controlled concentration and feeding rate as the cathode active material. To facilitate the design of such air intake systems, we have investigated the effects of oxygen partial pressure (≤1 atm) on the performance of the Li-air cell, which has not been systematically examined. The amounts of consumed O2 and evolved CO2 from the Li-air cell are measured with a custom in situ differential electrochemical gas chromatography-mass spectrometry (DEGC-MS). The amounts of consumed O2 suggest that the oxygen partial pressure does not affect the reaction mechanism during discharge, and the two-electron reaction occurs under all test conditions. On the other hand, the charging behavior varies by the oxygen partial pressure. The highest O2 evolution ratio is attained under 70% O2, along with the lowest CO2 evolution. The cell cycle life also peaks at 70% O2 condition. Overall, an oxygen partial pressure of about 0.5-0.7 atm maximizes the Li-air cell capacity and stability at 1 atm condition. The findings here indicate that the appropriate oxygen partial pressure can be a key factor when developing practical Li-air battery systems.

Extracellular vesicles and their synthetic analogues in aging and age-associated brain diseases

PubMed Central

Smith, J. A.; Leonardi, T.; Huang, B.; Iraci, N.; Vega, B.; Pluchino, S.

2015-01-01

Multicellular organisms rely upon diverse and complex intercellular communications networks for a myriad of physiological processes. Disruption of these processes is implicated in the onset and propagation of disease and disorder, including the mechanisms of senescence at both cellular and organismal levels. In recent years, secreted extracellular vesicles (EVs) have been identified as a particularly novel vector by which cell-to-cell communications are enacted. EVs actively and specifically traffic bioactive proteins, nucleic acids, and metabolites between cells at local and systemic levels, modulating cellular responses in a bidirectional manner under both homeostatic and pathological conditions. EVs are being implicated not only in the generic aging process, but also as vehicles of pathology in a number of age-related diseases, including cancer and neurodegenerative and disease. Thus, circulating EVs—or specific EV cargoes—are being utilised as putative biomarkers of disease. On the other hand, EVs, as targeted intercellular shuttles of multipotent bioactive payloads, have demonstrated promising therapeutic properties, which can potentially be modulated and enhanced through cellular engineering. Furthermore, there is considerable interest in employing nanomedicinal approaches to mimic the putative therapeutic properties of EVs by employing synthetic analogues for targeted drug delivery. Herein we describe what is known about the origin and nature of EVs and subsequently review their putative roles in biology and medicine (including the use of synthetic EV analogues), with a particular focus on their role in aging and age-related brain diseases. PMID:24973266

Epidemiology of hand, foot and mouth disease in China, 2008 to 2015 prior to the introduction of EV-A71 vaccine.

PubMed

Yang, Bingyi; Liu, Fengfeng; Liao, Qiaohong; Wu, Peng; Chang, Zhaorui; Huang, Jiao; Long, Lu; Luo, Li; Li, Yu; Leung, Gabriel M; Cowling, Benjamin J; Yu, Hongjie

2017-12-01

Hand, foot and mouth disease (HFMD) is usually caused by several serotypes from human enterovirus A species, including enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16). Two inactivated monovalent EV-A71 vaccines have been recently licensed in China and monovalent CV-A16 vaccine and bivalent EV-A71 and CV-A16 vaccine are under development. Using notifications from the national surveillance system, we describe the epidemiology and dynamics of HFMD in the country, before the introduction of EV-A71 vaccination, from 2008 through 2015. Laboratory-identified serotype categories, i.e. CV-A16, EV-A71 and other enteroviruses, circulated annually. EV-A71 remained the most virulent serotype and was the major serotype for fatal cases (range: 88.5-95.4%) and severe cases (range: 50.7-82.3%) across years. Except for 2013 and 2015, when other enteroviruses were more frequently found in mild HFMD (48.8% and 52.5%), EV-A71 was more frequently detected from mild cases in the rest of the years covered by the study (range: 39.4-52.6%). The incidence rates and severity risks of HFMD associated with all serotype categories were the highest for children aged 1 year and younger, and decreased with increasing age. This study provides baseline epidemiology for evaluation of vaccine impact and potential serotype replacement.

Life-cycle assessment of greenhouse gas and air emissions of electric vehicles: A comparison between China and the U.S.

NASA Astrophysics Data System (ADS)

Huo, Hong; Cai, Hao; Zhang, Qiang; Liu, Fei; He, Kebin

2015-05-01

We evaluated the fuel-cycle emissions of greenhouse gases (GHGs) and air pollutants (NOx, SO2, PM10, and PM2.5) of electric vehicles (EVs) in China and the United States (U.S.), two of the largest potential markets for EVs in the world. Six of the most economically developed and populated regions in China and the U.S. were selected. The results showed that EV fuel-cycle emissions depend substantially on the carbon intensity and cleanness of the electricity mix, and vary significantly across the regions studied. In those regions with a low share of coal-based electricity (e.g., California), EVs can reduce GHG and air pollutant emissions (except for PM) significantly compared with conventional vehicles. However, in the Chinese regions and selected U.S. Midwestern states where coal dominates in the generation mix, EVs can reduce GHG emissions but increase the total and urban emissions of air pollutants. In 2025, EVs will offer greater reductions in GHG and air pollutant emissions because emissions from power plants will be better controlled; EVs in the Chinese regions examined, however, may still increase SO2 and PM emissions. Reductions of 60-85% in GHGs and air pollutants could be achieved were EVs charged with 80% renewable electricity or the electricity generated from the best available technologies of coal-fired power plants, which are futuristic power generation scenarios.

Nasal Infection of Enterovirus D68 Leading to Lower Respiratory Tract Pathogenesis in Ferrets (Mustela putorius furo)

PubMed Central

Zheng, Hui-Wen; Sun, Ming; Guo, Lei; Wang, Jing-Jing; Song, Jie; Li, Jia-Qi; Li, Hong-Zhe; Ning, Ruo-Tong; Yang, Ze-Ning; Fan, Hai-Tao; He, Zhan-Long; Liu, Long-Ding

2017-01-01

Data from EV-D68-infected patients demonstrate that pathological changes in the lower respiratory tract are principally characterized by severe respiratory illness in children and acute flaccid myelitis. However, lack of a suitable animal model for EV-D68 infection has limited the study on the pathogenesis of this critical pathogen, and the development of a vaccine. Ferrets have been widely used to evaluate respiratory virus infections. In the current study, we used EV-D68-infected ferrets as a potential animal to identify impersonal indices, involving clinical features and histopathological changes in the upper and lower respiratory tract (URT and LRT). The research results demonstrate that the EV-D68 virus leads to minimal clinical symptoms in ferrets. According to the viral load detection in the feces, nasal, and respiratory tracts, the infection and shedding of EV-D68 in the ferret model was confirmed, and these results were supported by the EV-D68 VP1 immunofluorescence confocal imaging with α2,6-linked sialic acid (SA) in lung tissues. Furthermore, we detected the inflammatory cytokine/chemokine expression level, which implied high expression levels of interleukin (IL)-1a, IL-8, IL-5, IL-12, IL-13, and IL-17a in the lungs. These data indicate that systemic observation of responses following infection with EV-D68 in ferrets could be used as a model for EV-D68 infection and pathogenesis. PMID:28489053

Human Enterovirus 71 Protein Displayed on the Surface of Saccharomyces cerevisiae as an Oral Vaccine.

PubMed

Zhang, Congdang; Wang, Yi; Ma, Shuzhi; Li, Leike; Chen, Liyun; Yan, Huimin; Peng, Tao

2016-06-01

Human enterovirus 71 (EV-A71), a major agent of hand, foot, and mouth disease, has become an important public health issue in recent years. No effective antiviral or vaccines against EV-A71 infection are currently available. EV-A71 infection intrudes bodies through the gastric mucosal surface and it is necessary to enhance mucosal immune response to protect children from these pathogens. Recently, the majority of EV-A71 vaccine candidates have been developed for parenteral immunization. However, parenteral vaccine candidates often induce poor mucosal responses. On the other hand, oral vaccines could induce effective mucosal and systemic immunity, and could be easily and safely administered. Thus, proper oral vaccines have attached more interest compared with parenteral vaccine. In this study, the major immunogenic capsid protein of EV-A71 was displayed on the surface of Saccharomyces cerevisiae. Oral immunization of mice with surface-displayed VP1 S. cerevisiae induced systemic humoral and mucosal immune responses, including virus-neutralizing titers, VP1-specific antibody, and the induction of Th1 immune responses in the spleen. Furthermore, oral immunization of mother mice with surface-displayed VP1 S. cerevisiae conferred protection to neonatal mice against the lethal EV-A71 infection. Furthermore, we observed that multiple boost immunization as well as higher immunization dosage could induce higher EV-A71-specific immune response. Our results demonstrated that surface-displayed VP1 S. cerevisiae could be used as potential oral vaccine against EV-A71 infection.

Angiotensin II-Induced End-Organ Damage in Mice Is Attenuated by Human Exosomes and by an Exosomal Y RNA Fragment.

PubMed

Cambier, Linda; Giani, Jorge F; Liu, Weixin; Ijichi, Takeshi; Echavez, Antonio K; Valle, Jackelyn; Marbán, Eduardo

2018-06-04

Hypertension often leads to cardiovascular disease and kidney dysfunction. Exosomes secreted from cardiosphere-derived cells (CDC-exo) and their most abundant small RNA constituent, the Y RNA fragment EV-YF1, exert therapeutic benefits after myocardial infarction. Here, we investigated the effects of CDC-exo and EV-YF1, each administered individually, in a model of cardiac hypertrophy and kidney injury induced by chronic infusion of Ang (angiotensin) II. After 2 weeks of Ang II, multiple doses of CDC-exo or EV-YF1 were administered retro-orbitally. Ang II infusion induced an elevation in systolic blood pressure that was not affected by CDC-exo or EV-YF1. Echocardiography confirmed that Ang II infusion led to cardiac hypertrophy. CDC-exo and EV-YF1 both attenuated cardiac hypertrophy and reduced cardiac inflammation and fibrosis. In addition, both CDC-exo and EV-YF1 improved kidney function and diminished renal inflammation and fibrosis. The beneficial effects of CDC-exo and EV-YF1 were associated with changes in the expression of the anti-inflammatory cytokine IL (interleukin)-10 in plasma, heart, spleen, and kidney. In summary, infusions of CDC-exo or EV-YF1 attenuated cardiac hypertrophy and renal injury induced by Ang II infusion, without affecting blood pressure, in association with altered IL-10 expression. Exosomes and their defined noncoding RNA contents may represent potential new therapeutic approaches for hypertension-associated cardiovascular and renal damage. © 2018 American Heart Association, Inc.

Statistical model and first-principles simulation on concentration of HenV cluster and He bubble formation in α-Fe and W

NASA Astrophysics Data System (ADS)

Liu, Yue-Lin; Yu, Yang; Dai, Zhen-Hong

2015-01-01

Using first-principles calculations, we investigate the stabilities of He and Hen-vacancy (HenV) clusters in α-Fe and W. Vacancy formation energies are 2.08 eV in α-Fe and 3.11 eV in W, respectively. Single He in both α-Fe and W prefers to occupy the tetrahedral interstitial site. We recalculated the He solution energy considering the effect of zero-point energy (ZPE). The ZPEs of He in α-Fe and W at the tetrahedral (octahedral) interstitial site are 0.072 eV (0.031 eV) and 0.078 eV (0.034 eV), respectively. The trapping energies of single He at vacancy in α-Fe and W are -2.39 eV and -4.55 eV, respectively. By sequentially adding He into vacancy, a monovacancy trap up to 10 He atoms distributing in the vacancy vicinity. Based on the above results combined with statistical model, we evaluate the concentrations of all relevant HenV clusters as a function of He chemical potential. The critical HenV concentration is found to be ∼10-40 (atomic) at the critical temperature T = 600 K in α-Fe and T = 1600 K in W, respectively. Beyond the critical HenV concentrations, considerable HenV aggregate to form HenVm clusters. By further growing of HenVm, the HenVm clusters grow bigger resulting in the larger He bubble formation.

Naphthalene bisimides asymmetrically and symmetrically N-substituted with triarylamine--comparison of spectroscopic, electrochemical, electronic and self-assembly properties.

PubMed

Rybakiewicz, Renata; Zapala, Joanna; Djurado, David; Nowakowski, Robert; Toman, Petr; Pfleger, Jiri; Verilhac, Jean-Marie; Zagorska, Malgorzata; Pron, Adam

2013-02-07

Two semiconducting naphthalene bisimides were comparatively studied: NBI-(TAA)(2), symmetrically N-substituted with triaryl amine and asymmetric NBI-TAA-Oc with triaryl amine and octyl N-substituents. Both compounds show very similar spectroscopic and redox properties but differ in their supramolecular organization. As evidenced by STM, in monolayers on HOPG they form ordered 2D structures, however of different packing patterns. NBI-(TAA)(2) does not form ordered 3D structures, yielding amorphous thin films whereas films of NBI-TAA-Oc are highly crystalline. DFT calculations predict the ionization potential (IP) of 5.22 eV and 5.18 eV for NBI-TAA-Oc and NBI-(TAA)(2), respectively, as well as the electron affinity values (EA) of -3.25 eV and -3.22 eV. These results are consistent with the cyclic voltammetry data which yield similar values of IP (5.20 eV and 5.19 eV) and somehow different values of EA (-3.80 eV and -3.83 eV). As judged from these data, both semiconductors should exhibit ambipolar behavior. Indeed, NBI-TAA-Oc is ambipolar, showing hole and electron mobilities of 4.5 × 10(-5) cm(2)/(V s) and of 2.6 × 10(-4) cm(2)/(V s), respectively, in the field effect transistor configuration. NBI-(TAA)(2) is not ambipolar and yields field effect only in the p-channel configuration. This different behavior is rationalized on the basis of structural factors.

Nasal Infection of Enterovirus D68 Leading to Lower Respiratory Tract Pathogenesis in Ferrets (Mustela putorius furo).

PubMed

Zheng, Hui-Wen; Sun, Ming; Guo, Lei; Wang, Jing-Jing; Song, Jie; Li, Jia-Qi; Li, Hong-Zhe; Ning, Ruo-Tong; Yang, Ze-Ning; Fan, Hai-Tao; He, Zhan-Long; Liu, Long-Ding

2017-05-10

Data from EV-D68-infected patients demonstrate that pathological changes in the lower respiratory tract are principally characterized by severe respiratory illness in children and acute flaccid myelitis. However, lack of a suitable animal model for EV-D68 infection has limited the study on the pathogenesis of this critical pathogen, and the development of a vaccine. Ferrets have been widely used to evaluate respiratory virus infections. In the current study, we used EV-D68-infected ferrets as a potential animal to identify impersonal indices, involving clinical features and histopathological changes in the upper and lower respiratory tract (URT and LRT). The research results demonstrate that the EV-D68 virus leads to minimal clinical symptoms in ferrets. According to the viral load detection in the feces, nasal, and respiratory tracts, the infection and shedding of EV-D68 in the ferret model was confirmed, and these results were supported by the EV-D68 VP1 immunofluorescence confocal imaging with α2,6-linked sialic acid (SA) in lung tissues. Furthermore, we detected the inflammatory cytokine/chemokine expression level, which implied high expression levels of interleukin (IL)-1a, IL-8, IL-5, IL-12, IL-13, and IL-17a in the lungs. These data indicate that systemic observation of responses following infection with EV-D68 in ferrets could be used as a model for EV-D68 infection and pathogenesis.

Theory and computation of triply excited resonances: Application to states of He-

NASA Astrophysics Data System (ADS)

Nicolaides, Cleanthes A.; Piangos, Nicos A.; Komninos, Yannis

1993-11-01

Autoionizing multiply excited states offer unusual challenges to the theory of electronic structure and spectra because of the presence of strong electron correlations, of their occasional weak binding, of their proximity to more than one threshold, and of their degeneracy with many continua. Here we discuss a theory that addresses these difficulties in conjunction with the computation of their wave functions and intrinsic properties. Emphasis is given on the justification of the possible presence of self-consistently obtained open-channel-like (OCL) correlating configurations in the square-integrable representation of such states and on their effect on the energy E and the width Γ. Application of the theory has allowed the prediction of two hitherto unknown He- triply excited resonances, the 2s2p2 2P (E=59.71 eV, above the He ground state, Γ=79 meV) and the 2p3 2Do (E=59.46 eV, Γ=282 meV) (1 a.u.=27.2116 eV). These resonances are above the singly excited states of He and are embedded in its doubly excited spectrum. The relatively broad 2p3 2Do state interacts strongly with the He 2s2p 3Po ɛd continuum. The effect of this interaction has been studied in terms of the coupling with fixed core scattering states as well as with a self-consistently computed OCL bound configuration. The position of the He- 2p3 2Do resonance is below that of the He 2p2 1D autoionizing state at 59.91 eV and of the He 2p2 3P bound state at 59.68 eV. The partial decay widths to the three important open channels are γ(2s2p 3Po)=252 meV, γ(1s2p 3Po)=21 meV, γ(1s2p 1Po)=9 meV. The final core states are also represented by correlated (multiconfigurational Hartree-Fock) functions. The 2s2p2 2P state couples to four neighboring He thresholds, the 2s2p 3Po, 2p2 3P, 1D, and 2s2p 1Po. It is above the He 2s2p 3Po threshold at 58.31 eV, with respect to which it is a valence shape resonance, and below the He 2p2 1D and 2s2p 1Po autoionizing states. In the limit of an exact energy calculation, we suggest that its position would also come below that of the 2p2 3P state, which it overlaps. Its partial widths are γ(2s2p 3Po)=60 meV, γ(1s2p 3Po)=9 meV, γ(1s2p 1Po)=10 meV. The present results, considered together with published ones on other n=2 intrashell states, show that the recently measured [R. N. Gosselin and P. Marmet, Phys. Rev. A 41, 1335 (1990)] closely lying structures at 58.415 and 58.48 eV cannot correspond to the He- 2p3 4So and 2Do states, as these authors proposed.

Thermodynamics of Oxygen Ordering in Yttrium BARIUM(2) COPPER(3) OXYGEN(6+X)

NASA Astrophysics Data System (ADS)

Schieger, Paul Richard

An apparatus has been built to study and manipulate the oxygen in high temperature superconductors. It uses the principle of cryogenically assisted volumetric titration to precisely set changes in the oxygen content of high -T_{c} samples. The apparatus has been used to study the thermodynamics of oxygen in YBa_2Cu_3O _{6 + x} in order to help determine the correct model for oxygen thermodynamics as well as to provide standard curves for materials preparation by other methods. In particular, extensive measurements have been made on the oxygen pressure isotherms as a function of x for temperatures between 450^circ C and 650^circC. The measurement technique also allows one to extract the thermodynamic response function, (partial x/ partialmu)_{T}, ( mu is the chemical potential), which is sensitive to the oxygen configuration and which can be calculated by any candidate theory of the oxygen thermodynamics. Several existing theoretical models for the oxygen ordering thermodynamics are presented and compared to the experimental results. The models considered are classed into two basic approaches: lattice gas models and defect chemical models. It is found that the lattice gas models which assume static effective pair interactions between oxygen atoms, do not fit the experimental data very well, especially in the orthorhombic phase. The defect chemical models, which incorporate additional degrees of freedom (spin and charge) due to the creation of electronic defects, fit significantly better, but make crude assumptions for the configurational entropy of oxygen atoms. Using a commonly accepted picture for the creation of mobile electron holes and unpaired spins on the copper sites, it is possible to relate these quantities in terms of short range cluster probabilities defined in mean field approximations to the 2D lattice gas models. Based upon this connection, a thermodynamical model is developed, which takes into account interactions between oxygen atoms and the additional spin and charge degrees of freedom, assuming a narrow band, high temperature limit for the motion of the charge carriers. The model, containing the nearest-neighbour oxygen interaction (0.241eV) and the single site oxygen binding energy (-0.82eV - D/2; D is the dissociation energy of an oxygen molecule) as the only adjustable parameters, is compared to experimental results for the chemical potential, kT(partial x/partialmu)_{T}, fractional site occupancies, structural phase diagram, the number of monovalent coppers, and the total number of mobile electron holes. Qualitative agreement is found for all compared quantities, and quantitative agreement is found for the chemical potential, fractional site occupancies and kT(partial x/partialmu)_ {T} in the orthorhombic phase. Improvements to the model are outlined which should result in a quantitative fit to all results, in particular the valence and hole count vs. x. In addition to illuminating what is lacking in the commonly used two dimensional lattice gas models, the theory may form the basis for accurately predicting the electron hole count of the CuO_2 plane of YBa_2Cu_3 O_{6 + x} as a function of the sample preparation conditions.

Study of the modes of adsorption and electronic structure of hydrogen peroxide and ethanol over TiO2 rutile (110) surface within the context of water splitting

NASA Astrophysics Data System (ADS)

Alghamdi, H.; Idriss, H.

2018-03-01

While photocatalytic water splitting over many materials is favourable thermodynamically the kinetic of the reaction is very slow. One of the proposed reasons linked to the slow oxidation reaction rate is H2O2 formation as a reaction intermediate. Using Density Functional Theory (DFT) H2O2 is investigated on TiO2 rutile (110) surface to determine its most stable adsorption modes: molecular, (H)O(H)O - (a), partially dissociated, (H)OO - (a), and fully dissociated (a) - OO - (a). We then compare H2O2 interaction to that of a fast hole scavenger molecule, ethanol. Geometry, electronic structure, charge density difference and work function determination of both adsorbates are presented and compared using DFT with different functionals (PBE, PBE-D, PBE-U, and HSE + D). H2O2 is found to be strongly adsorbed on TiO2 rutile (110) surface with adsorption energies reaching 0.95 eV, comparable to that of ethanol (0.89 eV); using GGA PBE. The negative changes in the work function upon adsorption were found to be highest for molecular adsorption ( - 1.23 eV) and lowest for the fully dissociated mode ( - 0.54 eV) of H2O2. This may indicate that electrons flow from the surface to the adsorbate in order to make O(s)-H partially offset the overall magnitude of the oxygen lone pair interaction (of H2O2) with Ti4+ cations. Examination of the electronic structure through density of states (DOS) at the PBE level of computation, indicates that the H2O2 highest occupied molecular orbital (HOMO) level is not overlapping with oxygen atoms of TiO2 surface at any of its adsorption modes and at any of the computation methods. Some overlap is seen using the HSE + D computational method. On the other hand the dissociated mode of ethanol (ethoxides) does overlap with all computational methods used. The high adsorption energy and the absence of overlapping of the HOMO level of H2O2 with TiO2 rutile (110) surface may explain why water splitting is slow.

Valence and inner-valence shell dissociative photoionization of CO in the 26-33 eV range. II. Molecular-frame and recoil-frame photoelectron angular distributions.

PubMed

Lebech, M; Houver, J C; Raseev, G; dos Santos, A S; Dowek, D; Lucchese, Robert R

2012-03-07

Experimental and theoretical results for molecular-frame photoemission are presented for inner-valence shell photoionization of the CO molecule induced by linearly and circularly polarized light. The experimental recoil frame photoelectron angular distributions (RFPADs) obtained from dissociative photoionization measurements where the velocities of the ionic fragment and photoelectron were detected in coincidence, are compared to RFPADs computed using the multichannel Schwinger configuration interaction method. The formalism for including a finite lifetime of the predissociative ion state is presented for the case of general elliptically polarized light, to obtain the RFPAD rather than the molecular frame photoelectron angular distribution (MFPAD), which would be obtained with the assumption of instantaneous dissociation. We have considered photoionization of CO for the photon energies of 26.0 eV, 29.5 eV, and 32.5 eV. A comparison of experimental and theoretical RFPADs allows us to identify the ionic states detected in the experimental studies. In addition to previously identified states, we found evidence for the 2 (2)Δ state with an ionization potential of 25.3 eV and (2)Σ(+) states with ionization potentials near 32.5 eV. A comparison of the experimental and theoretical RFPADs permits us to estimate predissociative lifetimes of 0.25-1 ps for some of the ion states. Consideration of the MFPADs of a series of (2)Π ion states indicates the importance of inter-channel coupling at low photoelectron kinetic energy and the limitations of a single-channel analysis based on the corresponding Dyson orbitals. © 2012 American Institute of Physics

Potential impacts of electric vehicles on air quality in Taiwan.

PubMed

Li, Nan; Chen, Jen-Ping; Tsai, I-Chun; He, Qingyang; Chi, Szu-Yu; Lin, Yi-Chiu; Fu, Tzung-May

2016-10-01

The prospective impacts of electric vehicle (EV) penetration on the air quality in Taiwan were evaluated using an air quality model with the assumption of an ambitious replacement of current light-duty vehicles under different power generation scenarios. With full EV penetration (i.e., the replacement of all light-duty vehicles), CO, VOCs, NOx and PM2.5 emissions in Taiwan from a fleet of 20.6 million vehicles would be reduced by 1500, 165, 33.9 and 7.2Ggyr(-1), respectively, while electric sector NOx and SO2 emissions would be increased by up to 20.3 and 12.9Ggyr(-1), respectively, if the electricity to power EVs were provided by thermal power plants. The net impacts of these emission changes would be to reduce the annual mean surface concentrations of CO, VOCs, NOx and PM2.5 by about 260, 11.3, 3.3ppb and 2.1μgm(-3), respectively, but to increase SO2 by 0.1ppb. Larger reductions tend to occur at time and place of higher ambient concentrations and during high pollution events. Greater benefits would clearly be attained if clean energy sources were fully encouraged. EV penetration would also reduce the mean peak-time surface O3 concentrations by up to 7ppb across Taiwan with the exception of the center of metropolitan Taipei where the concentration increased by <2ppb. Furthermore, full EV penetration would reduce annual days of O3 pollution episodes by ~40% and PM2.5 pollution episodes by 6-10%. Our findings offer important insights into the air quality impacts of EV and can provide useful information for potential mitigation actions. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimal Decentralized Protocol for Electric Vehicle Charging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gan, LW; Topcu, U; Low, SH

We propose a decentralized algorithm to optimally schedule electric vehicle (EV) charging. The algorithm exploits the elasticity of electric vehicle loads to fill the valleys in electric load profiles. We first formulate the EV charging scheduling problem as an optimal control problem, whose objective is to impose a generalized notion of valley-filling, and study properties of optimal charging profiles. We then give a decentralized algorithm to iteratively solve the optimal control problem. In each iteration, EVs update their charging profiles according to the control signal broadcast by the utility company, and the utility company alters the control signal to guidemore » their updates. The algorithm converges to optimal charging profiles (that are as "flat" as they can possibly be) irrespective of the specifications (e.g., maximum charging rate and deadline) of EVs, even if EVs do not necessarily update their charging profiles in every iteration, and use potentially outdated control signal when they update. Moreover, the algorithm only requires each EV solving its local problem, hence its implementation requires low computation capability. We also extend the algorithm to track a given load profile and to real-time implementation.« less

Clean vehicles as an enabler for a clean electricity grid

NASA Astrophysics Data System (ADS)

Coignard, Jonathan; Saxena, Samveg; Greenblatt, Jeffery; Wang, Dai

2018-05-01

California has issued ambitious targets to decarbonize transportation through the deployment of electric vehicles (EVs), and to decarbonize the electricity grid through the expansion of both renewable generation and energy storage. These parallel efforts can provide an untapped synergistic opportunity for clean transportation to be an enabler for a clean electricity grid. To quantify this potential, we forecast the hourly system-wide balancing problems arising out to 2025 as more renewables are deployed and load continues to grow. We then quantify the system-wide balancing benefits from EVs modulating the charging or discharging of their batteries to mitigate renewable intermittency, without compromising the mobility needs of drivers. Our results show that with its EV deployment target and with only one-way charging control of EVs, California can achieve much of the same benefit of its Storage Mandate for mitigating renewable intermittency, but at a small fraction of the cost. Moreover, EVs provide many times these benefits if two-way charging control becomes widely available. Thus, EVs support the state’s renewable integration targets while avoiding much of the tremendous capital investment of stationary storage that can instead be applied towards further deployment of clean vehicles.

Extracellular vesicles in food: Experimental evidence of their secretion in grape fruits.

PubMed

Pérez-Bermúdez, Pedro; Blesa, Jesús; Soriano, José Miguel; Marcilla, Antonio

2017-02-15

In the last decade, the number of studies related with extracellular vesicles (EVs) has dramatically grown since their role as key part of intercellular communication has been confirmed. EVs, as transporter of distinct bioactive molecules, can take part in different physiological mechanisms and have been gaining attention as potential tools with a wide range of therapeutic effects. Whereas a high number of studies have been published related to mammalian derived EVs, including products as food source, the existence of EVs in plants still is controversial. Recent descriptions of vesicles derived from edible plants show that they might contain pharmacological active molecules. In this context, EVs from food are attracting increasing interest due to their relevance in modulating cellular processes (involved in health and disease), as well as therapeutic vehicles. The present work aims to summarize the current knowledge on exosomes in foods, actually limited to only four FAO groups (Milk, Starchy roots and tubers, Nuts and seeds, and Fruits). In addition, we have further characterized EVs isolated from grape berry juice by classical differential centrifugation, and described a preliminary dissection of their secretion in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

Extracellular vesicles and intercellular communication within the nervous system

PubMed Central

Fitzpatrick, Zachary; Maguire, Casey A.; Breakefield, Xandra O.

2016-01-01

Extracellular vesicles (EVs, including exosomes) are implicated in many aspects of nervous system development and function, including regulation of synaptic communication, synaptic strength, and nerve regeneration. They mediate the transfer of packets of information in the form of nonsecreted proteins and DNA/RNA protected within a membrane compartment. EVs are essential for the packaging and transport of many cell-fate proteins during development as well as many neurotoxic misfolded proteins during pathogenesis. This form of communication provides another dimension of cellular crosstalk, with the ability to assemble a “kit” of directional instructions made up of different molecular entities and address it to specific recipient cells. This multidimensional form of communication has special significance in the nervous system. How EVs help to orchestrate the wiring of the brain while allowing for plasticity associated with learning and memory and contribute to regeneration and degeneration are all under investigation. Because they carry specific disease-related RNAs and proteins, practical applications of EVs include potential uses as biomarkers and therapeutics. This Review describes our current understanding of EVs and serves as a springboard for future advances, which may reveal new important mechanisms by which EVs in coordinate brain and body function and dysfunction. PMID:27035811

An integrated double-filtration microfluidic device for isolation, enrichment and quantification of urinary extracellular vesicles for detection of bladder cancer

PubMed Central

Liang, Li-Guo; Kong, Meng-Qi; Zhou, Sherry; Sheng, Ye-Feng; Wang, Ping; Yu, Tao; Inci, Fatih; Kuo, Winston Patrick; Li, Lan-Juan; Demirci, Utkan; Wang, ShuQi

2017-01-01

Extracellular vesicles (EVs), including exosomes and microvesicles, are present in a variety of bodily fluids, and the concentration of these sub-cellular vesicles and their associated biomarkers (proteins, nucleic acids, and lipids) can be used to aid clinical diagnosis. Although ultracentrifugation is commonly used for isolation of EVs, it is highly time-consuming, labor-intensive and instrument-dependent for both research laboratories and clinical settings. Here, we developed an integrated double-filtration microfluidic device that isolated and enriched EVs with a size range of 30–200 nm from urine, and subsequently quantified the EVs via a microchip ELISA. Our results showed that the concentration of urinary EVs was significantly elevated in bladder cancer patients (n = 16) compared to healthy controls (n = 8). Receiver operating characteristic (ROC) analysis demonstrated that this integrated EV double-filtration device had a sensitivity of 81.3% at a specificity of 90% (16 bladder cancer patients and 8 healthy controls). Thus, this integrated device has great potential to be used in conjunction with urine cytology and cystoscopy to improve clinical diagnosis of bladder cancer in clinics and at point-of-care (POC) settings. PMID:28436447

Theoretical study of the electronic states of newly detected dications. Case of MgS2+ AND SiN2+

NASA Astrophysics Data System (ADS)

Khairat, Toufik; Salah, Mohammed; Marakchi, Khadija; Komiha, Najia

2017-08-01

The dications MgS2+ and SiN2+, experimentally observed by mass spectroscopy, are theoretically studied here. The potential energy curves of the electronic states of the two dications MgS2+ and SiN2+ are mapped and their spectroscopic parameters determined by analysis of the electronic, vibrational and rotational wave functions obtained by using complete active space self-consistent field (CASSCF) calculations, followed by the internally contracted multi-reference configuration interaction (MRCI)+Q associated with the AV5Z correlation consistent atomic orbitals basis sets. In the following, besides the characterization of the potential energy curves, excitation and dissociation energies, spectroscopic constants and a double-ionization spectra of MgS and SiN are determined using the transition moments values and Franck-Condon factors. The electronic ground states of the two dications appear to be of X3∑-nature for MgS2+ and X4∑- for SiN2+ and shows potential wells of about 1.20 eV and 1.40 eV, respectively. Several excited states of these doubly charged molecules also depicted here are slightly bound. The adiabatic double-ionization energies were deduced, at 21.4 eV and 18.4 eV, respectively, from the potential energy curves of the electronic ground states of the neutral and charged species. The neutral molecules, since involved, are also investigated here. From all these results, the experimental lines of the mass spectra of MgS and SiN could be partly assigned.

Built-In Potential in Fe 2 O 3 -Cr 2 O 3 Superlattices for Improved Photoexcited Carrier Separation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaspar, Tiffany C.; Schreiber, Daniel K.; Spurgeon, Steven R.

2015-12-17

We demonstrate that the different surface terminations exhibited by α-Fe2O3 (hematite) and α-Cr2O3 (eskolaite) in superlattices (SL) of these materials, synthesized with exquisite control by molecular beam epitaxy, determine the heterojunction interface structure and result in controllable, non-commutative band offset values. Precise atomic control of the interface structure allowed us to vary the valence band offset from 0.35 eV to 0.79 eV. This controllable band alignment can be harnessed to generate a built-in potential in Fe2O3-Cr2O3 SLs. For instance, in a 2.5-period SL, a built-in potential of 0.8 eV was realized as measured by x-ray photoelectron spectroscopy of Ti dopantsmore » as probe species. The high quality of the SL structure was confirmed by atom probe tomography and scanning transmission electron microscopy. Enhanced photocurrents were measured for a thick Fe2O3 epitaxial film capped with an (Fe2O3)3-(Cr2O3)3 SL; this enhancement was attributed to efficient electron-hole separation in the SL as a result of the band alignment. The Fe-O-Cr bonds at the SL interfaces also red-shifted the onset of photoconductivity to ~1.6 eV. Exploiting the band alignment and photoabsorption properties of Fe2O3-Cr2O3 SLs has the potential to increase the efficiency of hematite-based photoelectrochemical water splitting.« less

A quantum-rovibrational-state-selected study of the reaction in the collision energy range of 0.05-10.00 eV: translational, rotational, and vibrational energy effects.

PubMed

Xu, Yuntao; Xiong, Bo; Chang, Yih-Chung; Pan, Yi; Lo, Po Kam; Lau, Kai Chung; Ng, C Y

2017-04-12

We report detailed absolute integral cross sections (σ's) for the quantum-rovibrational-state-selected ion-molecule reaction in the center-of-mass collision energy (E cm ) range of 0.05-10.00 eV, where (vvv) = (000), (100), and (020), and . Three product channels, HCO + + OH, HOCO + + H, and CO + + H 2 O, are identified. The measured σ(HCO + ) curve [σ(HCO + ) versus E cm plot] supports the hypothesis that the formation of the HCO + + OH channel follows an exothermic pathway with no potential energy barriers. Although the HOCO + + H channel is the most exothermic, the σ(HOCO + ) is found to be significantly lower than the σ(HCO + ). The σ(HOCO + ) curve is bimodal, indicating two distinct mechanisms for the formation of HOCO + . The σ(HOCO + ) is strongly inhibited at E cm < 0.4 eV, but is enhanced at E cm > 0.4 eV by (100) vibrational excitation. The E cm onsets of σ(CO + ) determined for the (000) and (100) vibrational states are in excellent agreement with the known thermochemical thresholds. This observation, along with the comparison of the σ(CO + ) curves for the (100) and (000) states, shows that kinetic and vibrational energies are equally effective in promoting the CO + channel. We have also performed high-level ab initio quantum calculations on the potential energy surface, intermediates, and transition state structures for the titled reaction. The calculations reveal potential barriers of ≈0.5-0.6 eV for the formation of HOCO + , and thus account for the low σ(HOCO + ) and its bimodal profile observed. The E cm enhancement for σ(HOCO + ) at E cm ≈ 0.5-5.0 eV can be attributed to the direct collision mechanism, whereas the formation of HOCO + at low E cm < 0.4 eV may involve a complex mechanism, which is mediated by the formation of a loosely sticking complex between HCO + and OH. The direct collision and complex mechanisms proposed also allow the rationalization of the vibrational inhibition at low E cm and the vibrational enhancement at high E cm observed for the σ(HOCO + ).

Phosphoproteins in extracellular vesicles as candidate markers for breast cancer

PubMed Central

Chen, I-Hsuan; Xue, Liang; Hsu, Chuan-Chih; Paez, Juan Sebastian Paez; Pan, Li; Andaluz, Hillary; Wendt, Michael K.; Iliuk, Anton B.; Tao, W. Andy

2017-01-01

The state of protein phosphorylation can be a key determinant of cellular physiology such as early-stage cancer, but the development of phosphoproteins in biofluids for disease diagnosis remains elusive. Here we demonstrate a strategy to isolate and identify phosphoproteins in extracellular vesicles (EVs) from human plasma as potential markers to differentiate disease from healthy states. We identified close to 10,000 unique phosphopeptides in EVs isolated from small volumes of plasma samples. Using label-free quantitative phosphoproteomics, we identified 144 phosphoproteins in plasma EVs that are significantly higher in patients diagnosed with breast cancer compared with healthy controls. Several biomarkers were validated in individual patients using paralleled reaction monitoring for targeted quantitation. This study demonstrates that the development of phosphoproteins in plasma EV as disease biomarkers is highly feasible and may transform cancer screening and monitoring. PMID:28270605

Phosphoproteins in extracellular vesicles as candidate markers for breast cancer.

PubMed

Chen, I-Hsuan; Xue, Liang; Hsu, Chuan-Chih; Paez, Juan Sebastian Paez; Pan, Li; Andaluz, Hillary; Wendt, Michael K; Iliuk, Anton B; Zhu, Jian-Kang; Tao, W Andy

2017-03-21

The state of protein phosphorylation can be a key determinant of cellular physiology such as early-stage cancer, but the development of phosphoproteins in biofluids for disease diagnosis remains elusive. Here we demonstrate a strategy to isolate and identify phosphoproteins in extracellular vesicles (EVs) from human plasma as potential markers to differentiate disease from healthy states. We identified close to 10,000 unique phosphopeptides in EVs isolated from small volumes of plasma samples. Using label-free quantitative phosphoproteomics, we identified 144 phosphoproteins in plasma EVs that are significantly higher in patients diagnosed with breast cancer compared with healthy controls. Several biomarkers were validated in individual patients using paralleled reaction monitoring for targeted quantitation. This study demonstrates that the development of phosphoproteins in plasma EV as disease biomarkers is highly feasible and may transform cancer screening and monitoring.

Production of EV71 vaccine candidates

PubMed Central

Chong, Pele; Hsieh, Shih-Yang; Liu, Chia-Chyi; Chou, Ai-Hsiang; Chang, Jui-Yuan; Wu, Suh-Chin; Liu, Shih-Jen; Chow, Yen-Hung; Su, Ih-Jen; Klein, Michel

2012-01-01

Enterovirus 71 (EV71) is now recognized as an emerging neurotropic virus in Asia and with Coxsackie virus (CV) it is the other major causative agent of hand-foot-mouth diseases (HFMD). Effective medications and/or prophylactic vaccines against HFMD are urgently needed. From a scientific (the feasibility of bioprocess, immunological responses and potency in animal challenge model) and business development (cost of goods) points of view, we in this review address and discuss the pros and cons of different EV71 vaccine candidates that have been produced and evaluated in animal models. Epitope-based synthetic peptide vaccine candidates containing residues 211–225 of VP1 formulated with Freund’s adjuvant (CFA/IFA) elicited low EV71 virus neutralizing antibody responses, but were protective in the suckling mouse challenge model. Among recombinant EV71 subunits (rVP1, rVP2 and rVP3) expressed in E. coli, purified and formulated with CFA/IFA, only VP1 elicited mouse antibody responses with measurable EV71-specific virus neutralization titers. Immunization of mice with either a DNA plasmid containing VP1 gene or VP1 expressed in Salmonella typhimurium also generated neutralizing antibody responses and protected animals against a live EV71 challenge. Recombinant EV71 virus-like particles (rVLP) produced from baculovirus formulated either with CFA/IFA or alum elicited good virus neutralization titers in both mice and non-human primates, and were found to be protective in the suckling mouse EV71 challenge model. Synthetic peptides or recombinant EV71 subunit vaccines (rVP1 and rVLP) formulated in alum were found to be poorly immunogenic in rabbits. Only formalin-inactivated (FI) EV71 virions formulated in alum elicited cross-neutralizing antibodies against different EV71 genotypes in mice, rabbits and non-human primates but induced weak neutralizing responses against CAV16. From a regulatory, economic and market acceptability standpoint, FI-EV71 virion vaccines are the most promising candidates and are currently being evaluated in human clinical trials. We further describe and analyze some new bioprocesses technologies that have great potential applications in EV71 vaccine development. This review also demonstrates the opportunities and challenges that the Asian vaccine industry faces today. PMID:22992566

DFT simulation on H2 adsorption over Ni-decorated defective h-BN nanosheets

NASA Astrophysics Data System (ADS)

Zhou, Xuan; Chu, Wei; Zhou, Yanan; Sun, Wenjing; Xue, Ying

2018-05-01

Nickel doped defective h-BN nanosheets and their potential application on hydrogen storage were explored by density functional theory (DFT) calculation. Three types of defective h-BN (SW defect, VB and VN substrates) were modeled. In comparison with the SW defect, the B or N vacancy can improve the interaction between Ni atom and h-BN nanosheet strikingly. Furthermore, the Ni-doped SW defect sheet shows chemisorption on H2 molecules, and the Hsbnd H bond is partially dissociated. While on the VB sheet, Ni adatom interacts with H2 in the range of physisorption. However, the Ni-functionalized VN sheet exhibits a desirable adsorption on H2, and the corresponding energy varies from -0.40 to -0.51 eV, which is favorable for H2 adsorption and release at ambient conditions. As a result, the VN substrate is expected to a desirable support for H2 storage. Our work provides an insight into H2 storage on Ni-functionalized defective h-BN monolayer.

New multifunctional materials obtained by the intercalation of anionic dyes into layered zinc hydroxide nitrate followed by dispersion into poly(vinyl alcohol) (PVA).

PubMed

Marangoni, Rafael; Ramos, Luiz Pereira; Wypych, Fernando

2009-02-15

Different anionic blue and orange dyes have been immobilized on a zinc hydroxide nitrate (Zn(5)(OH)(8)(NO(3))(2)nH(2)O--Zn-OH-NO(3)) by anion exchange with interlayer and/or outer surface nitrate ions of the layered matrix. Orange G (OG) was totally intercalated, orange II (OII) was partially intercalated, while Niagara blue 3B (NB) and Evans blue (EV) were only adsorbed at the outer surface. Several composite films of poly(vinyl alcohol)--PVA were prepared by casting through the dispersion of the hybrid material (Zn-OH-OG) into a PVA aqueous solution and evaporation of water in a vacuum oven. The obtained composite films were transparent, colored, and capable of absorbing UV radiation. Improved mechanical properties were also obtained in relation to the nonfilled PVA films. These results demonstrate the onset of a new range of potential applications for layered hydroxide salts in the preparation of polymer composite multifunctional materials.

Positron elastic scattering from alkaline earth targets

NASA Astrophysics Data System (ADS)

Poveda, Luis A.; Assafrão, Denise; Mohallem, José R.

2016-07-01

A previously reported model potential approach [Poveda et al., Phys. Rev. A 87, 052702 (2013)] was extended to study low energy positron elastic scattering from beryllium and magnesium. The cross sections were computed for energies ranging from 10-5 eV up to well above the positronium formation threshold. The present results are in good agreement with previous reports, including the prediction of a p-wave resonance in the cross section for magnesium. The emergence of this shape resonance is connected to a trend observed in the evolution of the partial wave cross section in going from Be to Mg target. This trend lead us to speculate that a sharp d-wave resonance should be observed in positron elastic scattering from calcium. The positron-target binding energies are investigated in detail, both using the scattering information and by direct computation of the bound state energies using the model potentials. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2016-70120-y

Time-Resolved K-shell Photoabsorption Edge Measurement in a Strongly Coupled Matter Driven by Laser-converted Radiation

NASA Astrophysics Data System (ADS)

Zhao, Yang; Yang, Jia-Min; Zhang, Ji-Yan; Yang, Guo-Hong; Xiong, Gang; Wei, Min-Xi; Song, Tian-Ming; Zhang, Zhi-Yu

2013-06-01

A time-resolved K edge absorption measurement of warm dense KCl was performed on Shenguang II laser facility. The x-ray radiation driven shocks were adopted to take colliding shocks compression. By using Dog bone hohlraum the CH/KCl/CH sample was shielded from the laser hitting point to suppress the M band preheating and enhance the compressibility. Thus, an unexplored and extreme region of the plasma state with the maximum 5 times solid density and temperature lower than 3 eV (with coupling constant Γii around 100) was first obtained. The photoabsorption spectra of chlorine near the K-shell edge have been measured with a crystal spectrometer using a short x-ray backlighter. The K edge red shift up to 11.7 eV and broadening of 15.2 eV were obtained for the maximum compression. The electron temperature, inferred by Fermi-Dirac fit of the measured K-edge broadening, was consistent with the hydrodynamic predictions. The comparison of the K edge shift with a plasma model, in which the ionization effect, continuum lowering and partial degeneracy are considered, shows that more improvements are desired to describe in details the variation of K edge shift. This work might extend future study of WDM in extreme conditions of high compression.

Temperature-dependent and anisotropic optical response of layered Pr0.5Ca1.5MnO4 probed by spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Majidi, M. A.; Thoeng, E.; Gogoi, P. K.; Wendt, F.; Wang, S. H.; Santoso, I.; Asmara, T. C.; Handayani, I. P.; van Loosdrecht, P. H. M.; Nugroho, A. A.; Rübhausen, M.; Rusydi, A.

2013-06-01

We study the temperature dependence as well as anisotropy of optical conductivity (σ1) in the pseudocubic single crystal Pr0.5Ca1.5MnO4 using spectrocopic ellipsometry. Three transition temperatures are observed and can be linked to charge-orbital (TCO/OO˜320 K), two-dimensional-antiferromagnetic (2D-AFM) (˜200 K), and three-dimensional AFM (TN˜125 K) orderings. Below TCO/OO, σ1 shows a charge-ordering peak (˜0.8 eV) with a significant blue shift as the temperature decreases. Calculations based on a model that incorporates a static Jahn-Teller distortion and assumes the existence of a local charge imbalance between two different sublattices support this assignment and explain the blue shift. This view is further supported by the partial spectral weight analysis showing the onset of optical anisotropy at TCO/OO in the charge-ordering region (0.5-2.5 eV). Interestingly, in the charge-transfer region (2.5-4 eV), the spectral weight shows anomalies around the T2D-AFM that we attribute to the role of oxygen-p orbitals in stabilizing the CE-type magnetic ordering. Our result shows the importance of spin, charge, orbital, and lattice degrees of freedom in this layered manganite.

Interventional Radiologic Treatment for Idiopathic Portal Hypertension

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirota, Shozo; Ichikawa, Satoshi; Matsumoto, Shinichi

1999-07-15

Purpose: To evaluate the usefulness of interventional radiological treatment for idiopathic portal hypertension. Methods: Between 1995 and 1998, we performed an interventional radiological treatment in five patients with idiopathic portal hypertension, four of whom had refused surgery and one of whom had undergone surgery. Three patients with gastroesophageal varices (GEV) were treated by partial splenic embolization (PSE), one patient with esophageal varices (EV) and massive ascites by transjugular intrahepatic portosytemic shunt (TIPS) and PSE, and one patient with GEV by percutaneous transhepatic obliteration (PTO). Midterm results were analyzed in terms of the effect on esophageal and/or gastric varices. Results: Inmore » one woman with severe GEV who underwent three sessions of PSE, there was endoscopic confirmation that the GEV had disappeared. In one man his EV shrunk markedly after two sessions of PSE. In two patients slight reduction of the EV was obtained with one application of PSE combined with endoscopic variceal ligation therapy. PTO for GV in one patient resulted in good control of the varices. All patients have survived for 16-42 months since the first interventional treatment, and varices are well controlled. Conclusion: Interventional radiological treatment is effective for patients with idiopathic portal hypertension, whether or not they have undergone surgery.« less

Stabilization of Reactive MgO Surfaces by Ni Doping

NASA Astrophysics Data System (ADS)

Mazheika, Aliaksei; Levchenko, Sergey V.

Ni-MgO solid solutions are promising materials for catalytic reduction of CO2 and dry reforming of CH4. To explain the catalytic activity, an ab initio study of Ni-substitutional defects in MgO (NiMg) has been performed. At first, the validation of the theory level was done. We compared results of CCSD(T) embedded-cluster calculations of NiMg formation energies and adsorption energies of CO, CO2 and H2 on them to the HSE(α) hybrid DFT functional with the fraction of the exact exchange α varied between 0 and 1. HSE(0.3) was found to be the best compromise in this study. Our periodic HSE(0.3) calculations show that NiMg defects are most stable at corner sites, followed by steps, and are least stable at (001) terraces. Thus, Ni-doping stabilizes stepped MgO surfaces. The dissociative adsorption of H2 on the terrace is found to be endothermic (+ 1 . 1 eV), whereas on (110) surface with NiMg it is highly exothermic (- 1 . 6 eV). Adsorbed CO2 is also significantly stabilized (- 0 . 6 vs. - 2 . 2 eV). These findings explain recent microcalorimetry measurements of H2 and CO2 adsorption at doped Ni-MgO samples. partially supported by UniCat (Deutsche Forschungsgemeinschaft).

Observation of the effects of stronger magnetic fields on warm, higher energy electrons and ion beams transiting a double layer in a helicon plasma

NASA Astrophysics Data System (ADS)

Scharer, John; Sung, Yung-Ta; Li, Yan

2017-10-01

Fast, two-temperature electrons (>80 eV, Te =13 eV tail, 4 eV bulk) with substantial tail density fractions are created at low (< = 1.7 mtorr) Ar pressure @ 340 G in the antenna region with nozzle mirror ratio of 1.4 on MadHeX @ 900W. These distributions including a fast tail are observed upstream of a double layer. The fast, untrapped tail electrons measured downstream of the double layer have a higher temperature of 13 eV than the trapped, upstream electrons of 4 eV temperature. Upstream plasma potential fluctuations of + - 30 percent are observed. An RF-compensated Langmuir probe is used to measure the electron temperatures and densities and OES, mm wave IF and an RPA for the IEDF are also utilized. As the magnetic field is increased to 1020 G, an increase in the electron temperature and density upstream of the double layer is observed with Te= 15-25 eV with a primarily single temperature mode. Accelerated ion beam energies in the range of 65-120 eV are observed as the magnetic field is increased from 340 to 850 G. The role of the nozzle, plasma double layer and helicon wave coupling on the EEDF and ion acceleration will be discussed. Research supported in part by the University of Wisconsin.

Dynamics Simulations and Statistical Modeling of Thermal Decomposition of 1-Ethyl-3-methylimidazolium Dicyanamide and 1-Ethyl-2,3-dimethylimidazolium Dicyanamide

DTIC Science & Technology

2014-10-02

SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON G. Vaghjiani c...Evib of EMIM +DCA− (eV) 0.33 1.66 2.67 3.78 18.34 Evib of EMMIM +DCA− (eV) 0.37 1.88 3.02 4.28 20.80 Erot (eV) 0.04 0.1 0.13 0.16 0.52 The Journal of...Intramolecular and Nonlinear Dynamics; JAI: Greenwich, U.K., 1998. ( 18 ) Sun, L.; Song, K.; Hase, W. L. A Sn2 Reaction That Avoids Its Deep Potential

A mouse model of paralytic myelitis caused by enterovirus D68

PubMed Central

Yu, Guixia; Leser, J. Smith; Yagi, Shigeo; Tyler, Kenneth L.

2017-01-01

In 2014, the United States experienced an epidemic of acute flaccid myelitis (AFM) cases in children coincident with a nationwide outbreak of enterovirus D68 (EV-D68) respiratory disease. Up to half of the 2014 AFM patients had EV-D68 RNA detected by RT-PCR in their respiratory secretions, although EV-D68 was only detected in cerebrospinal fluid (CSF) from one 2014 AFM patient. Given previously described molecular and epidemiologic associations between EV-D68 and AFM, we sought to develop an animal model by screening seven EV-D68 strains for the ability to induce neurological disease in neonatal mice. We found that four EV-D68 strains from the 2014 outbreak (out of five tested) produced a paralytic disease in mice resembling human AFM. The remaining 2014 strain, as well as 1962 prototype EV-D68 strains Fermon and Rhyne, did not produce, or rarely produced, paralysis in mice. In-depth examination of the paralysis caused by a representative 2014 strain, MO/14-18947, revealed infectious virus, virion particles, and viral genome in the spinal cords of paralyzed mice. Paralysis was elicited in mice following intramuscular, intracerebral, intraperitoneal, and intranasal infection, in descending frequency, and was associated with infection and loss of motor neurons in the anterior horns of spinal cord segments corresponding to paralyzed limbs. Virus isolated from spinal cords of infected mice transmitted disease when injected into naïve mice, fulfilling Koch’s postulates in this model. Finally, we found that EV-D68 immune sera, but not normal mouse sera, protected mice from development of paralysis and death when administered prior to viral challenge. These studies establish an experimental model to study EV-D68-induced myelitis and to better understand disease pathogenesis and develop potential therapies. PMID:28231269

Formononetin inhibits enterovirus 71 replication by regulating COX- 2/PGE₂ expression.

PubMed

Wang, Huiqiang; Zhang, Dajun; Ge, Miao; Li, Zhuorong; Jiang, Jiandong; Li, Yuhuan

2015-03-01

The activation of ERK, p38 and JNK signal cascade in host cells has been demonstrated to up-regulate of enterovirus 71 (EV71)-induced cyclooxygenase-2 (COX-2)/ prostaglandins E2 (PGE₂) expression which is essential for viral replication. So, we want to know whether a compound can inhibit EV71 infection by suppressing COX-2/PGE₂ expression. The antiviral effect of formononetin was determined by cytopathic effect (CPE) assay and the time course assays. The influence of formononetin for EV71 replication was determined by immunofluorescence assay, western blotting assay and qRT-PCR assay. The mechanism of the antiviral activity of formononetin was determined by western blotting assay and ELISA assay. Formononetin could reduce EV71 RNA and protein synthesis in a dose-dependent manner. The time course assays showed that formononetin displayed significant antiviral activity both before (24 or 12 h) and after (0-6 h) EV71 inoculation in SK-N-SH cells. Formononetin was also able to prevent EV71-induced cytopathic effect (CPE) and suppress the activation of ERK, p38 and JNK signal pathways. Furthermore, formononetin could suppress the EV71-induced COX-2/PGE₂ expression. Also, formononetin exhibited similar antiviral activities against other members of Picornaviridae including coxsackievirus B2 (CVB2), coxsackievirus B3 (CVB3) and coxsackievirus B6 (CVB6). Formononetin could inhibit EV71-induced COX-2 expression and PGE₂ production via MAPKs pathway including ERK, p38 and JNK. Formononetin exhibited antiviral activities against some members of Picornaviridae. These findings suggest that formononetin could be a potential lead or supplement for the development of new anti-EV71 agents in the future.

Proton and hydrogen transport through two-dimensional monolayers

NASA Astrophysics Data System (ADS)

Seel, Max; Pandey, Ravindra

2016-06-01

Diffusion of protons and hydrogen atoms in representative two-dimensional materials is investigated. Specifically, density functional calculations were performed on graphene, hexagonal boron nitride (h-BN), phosphorene, silicene, and molybdenum disulfide (MoS2) monolayers to study the surface interaction and penetration barriers for protons and hydrogen atoms employing finite cluster models. The calculated barrier heights correlate approximately with the size of the opening formed by the three-fold open sites in the monolayers considered. They range from 1.56 eV (proton) and 4.61 eV (H) for graphene to 0.12 eV (proton) and 0.20 eV (H) for silicene. The results indicate that only graphene and h-BN monolayers have the potential for membranes with high selective permeability. The MoS2 monolayer behaves differently: protons and H atoms become trapped between the outer S layers in the Mo plane in a well with a depth of 1.56 eV (proton) and 1.5 eV (H atom), possibly explaining why no proton transport was detected, suggesting MoS2 as a hydrogen storage material instead. For graphene and h-BN, off-center proton penetration reduces the barrier to 1.38 eV for graphene and 0.11 eV for h-BN. Furthermore, Pt acting as a substrate was found to have a negligible effect on the barrier height. In defective graphene, the smallest barrier for proton diffusion (1.05 eV) is found for an oxygen-terminated defect. Therefore, it seems more likely that thermal protons can penetrate a monolayer of h-BN but not graphene and defects are necessary to facilitate the proton transport in graphene.

The Use of Electronic Voting Systems in Lectures within Business and Marketing: A Case Study of Their Impact on Student Learning

ERIC Educational Resources Information Center

Masikunas, George; Panayiotidis, Andreas; Burke, Linda

2007-01-01

This article presents a case study of the impact on student learning of introducing an electronic voting system (EVS) into large-group lectures for first-year undergraduate students undertaking degrees in marketing and business systems. We discuss the potential for using EVS-style interactive lectures in marketing and business programmes. We then…

Plasma-derived Extracellular Vesicles Contain Predictive Biomarkers and Potential Therapeutic Targets for Myocardial Ischemic (MI) Injury*

PubMed Central

Cheow, Esther Sok Hwee; Cheng, Woo Chin; Lee, Chuen Neng; de Kleijn, Dominique; Sorokin, Vitaly; Sze, Siu Kwan

2016-01-01

Myocardial infarction (MI) triggers a potent inflammatory response via the release of circulatory mediators, including extracellular vesicles (EVs) by damaged cardiac cells, necessary for myocardial healing. Timely repression of inflammatory response are critical to prevent and minimize cardiac tissue injuries, nonetheless, progression in this aspect remains challenging. The ability of EVs to trigger a functional response upon delivery of carried bioactive cargos, have made them clinically attractive diagnostic biomarkers and vectors for therapeutic interventions. Using label-free quantitative proteomics approach, we compared the protein cargo of plasma EVs between patients with MI and from patients with stable angina (NMI). We report, for the first time, the proteomics profiling on 252 EV proteins that were modulated with >1.2-fold after MI. We identified six up-regulated biomarkers with potential for clinical applications; these reflected post-infarct pathways of complement activation (Complement C1q subcomponent subunit A (C1QA), 3.23-fold change, p = 0.012; Complement C5 (C5), 1.27-fold change, p = 0.087), lipoprotein metabolism (Apoliporotein D (APOD), 1.86-fold change, p = 0.033; Apolipoprotein C-III (APOCC3), 2.63-fold change, p = 0.029) and platelet activation (Platelet glycoprotein Ib alpha chain (GP1BA), 9.18-fold change, p < 0.0001; Platelet basic protein (PPBP), 4.72-fold change, p = 0.027). The data have been deposited to the ProteomeXchange with identifier PXD002950. This novel biomarker panel was validated in 43 patients using antibody-based assays (C1QA (p = 0.005); C5 (p = 0.0047), APOD (p = 0.0267); APOC3 (p = 0.0064); GP1BA (p = 0.0031); PPBP (p = 0.0465)). We further present that EV-derived fibrinogen components were paradoxically down-regulated in MI, suggesting that a compensatory mechanism may suppress post-infarct coagulation pathways, indicating potential for therapeutic targeting of this mechanism in MI. Taken together, these data demonstrated that plasma EVs contain novel diagnostic biomarkers and therapeutic targets that can be further developed for clinical use to benefit patients with coronary artery diseases (CADs). PMID:27234505

Measurement of magnetic field aligned potential differences using high resolution conjugate photoelectron energy spectra

NASA Technical Reports Server (NTRS)

Peterson, W. K.; Doering, J. P.; Potemra, T. A.; Bostrom, C. O.; Brace, L. H.; Heelis, R. A.; Hanson, W. B.

1977-01-01

Simultaneous high-resolution observations of a distinctive feature in the energy spectrum of conjugate photoelectrons and spacecraft potential relative to the local ionosphere have allowed the net potential difference between magnetic conjugate points at latitudes below the region of low-energy (i.e., lower than 100 eV) auroral electron precipitation to be determined. Measurements made at 300 km from Atmosphere Explorer C show that there is normally no net potential difference between hemispheres in this region, which extended up to invariant latitudes as high as 74 deg. Two types of apparently related anomalous behavior were infrequently observed at high latitudes. During these periods the incident flux of conjugate photoelectrons was either decelerated by about 3 eV or was not detected.

[Synthesis and spectral characteristics of novel di-schiff base derivatives incorporting oxadiazole ring].

PubMed

Chen, Tong-bin; Zhang, Xiong-lu; Fan, Xiao-lin; Li, Xun

2008-12-01

4-nitrobenzoic acid and hydraxine sulfate were cyclized with H3PO4/P2O5 to afford 2,5-bis(4-nitrophenyl)-1, 3,4-oxadiazole(1), then(1)was reduced to 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole using Zn/CaCl2 as reduction reagent, and at last, a series of novel di-schiff base derivatives containing oxadiazole ring were obtained by the reaction of 2,5-bis(4-aminophenyl)-1, 3,4-oxadiazole with aromatic aldehydes (yield: 65%-81%). The structures of these compounds were confirmed by 1H NMR, FTIR and MS. Their UV-Vis spectra as well as fluorescence spectra were studied and the electrochemical properties were tested with cyclic voltammetry. The UV-Vis spectroscopy results show that the characteristic absorption peaks of 1, 3, 4-oxadiazole unit and di-schiff base unit disappeared. The maximum absorption wavelength was detected at 345-357 nm because conjugation effect made the two energy bands partially hybrid and form a new energy band structure. Fluorescence spectroscopy results show that they emit strong blue and purple fluorescence, and the emission maximum wavelengths of di-schiff base are from 390 to 407 nm. Electrochemical properties results show that they have higher affinity energy (2.36-3.04 eV) and ionic potential (5.35-6.06 eV), which indicated that they have better electron-transporting properties than PBD except 3 a and 3 h. The results give a reference to further application to organic electroluminescent devices of the target compound.

Enterovirus genotypes causing hand foot and mouth disease in Shanghai, China: a molecular epidemiological analysis

PubMed Central

2013-01-01

Background A rapid expansion of hand, foot, and mouth disease (HFMD) outbreaks has occurred and caused deaths in China in recent years, but little is known about the other etiologic agents except enterovirus 71 (EV71) and coxsackievirus A 16 (CA16). The objective of this study is to determine the genotype compositions of enterovirus causing HFMD in Shanghai and identify any associations between enterovirus types and clinical manifestations. Methods Stool specimens were collected from patients hospitalized for treatment of HFMD, from May 2010 to April 2011. Enterovirus was detected by reverse transcription PCR and directly genotyped by sequencing the PCR products. Phylogenetic analysis was based on the VP1 partial gene. Results Of 290 specimens, 277 (95.5%) tested positive for enterovirus. The major genotypes were EV71 (63.8%), CA10 (9.0%), CA6 (8.3%), CA16 (6.9%), CA12 (2.4%), and CA4 (1.4%). The EV71 strains belonged to the C4a subtype and CA16 belonged to the B subtype. CA6 was closely related to strains detected in Japan, Taiwan and China, and CA10, CA12 and CA4 were phylogenetically similar to other strains circulating in China. Mean hospital stays and the prevalence of complications in patients with EV71 infection were higher than those in patients in CA6, CA10 or CA16 infection (P < 0.05 for all comparisons). Children with CA12 infection were the youngest, and most likely have the highest risk of complications when compared to the other non-EV71 infection groups. Conclusions This study demonstrated a diversified pathogen compositions attributing to HFMD and clinical symptoms differing in enterovirus genotypes. It deserves our attention as early identification of enterovirus genotypes is important for diagnosis and treatment of HFMD patients. PMID:24148902

Wide range scaling laws for radiation driven shock speed, wall albedo and ablation parameters for high-Z materials

NASA Astrophysics Data System (ADS)

Mishra, Gaurav; Ghosh, Karabi; Ray, Aditi; Gupta, N. K.

2018-06-01

Radiation hydrodynamic (RHD) simulations for four different potential high-Z hohlraum materials, namely Tungsten (W), Gold (Au), Lead (Pb), and Uranium (U) are performed in order to investigate their performance with respect to x-ray absorption, re-emission and ablation properties, when irradiated by constant temperature drives. A universal functional form is derived for estimating time dependent wall albedo for high-Z materials. Among the high-Z materials studied, it is observed that for a fixed simulation time the albedo is maximum for Au below 250 eV, whereas it is maximum for U above 250 eV. New scaling laws for shock speed vs drive temperature, applicable over a wide temperature range of 100 eV to 500 eV, are proposed based on the physics of x-ray driven stationary ablation. The resulting scaling relation for a reference material Aluminium (Al), shows good agreement with that of Kauffman's power law for temperatures ranging from 100 eV to 275 eV. New scaling relations are also obtained for temperature dependent mass ablation rate and ablation pressure, through RHD simulation. Finally, our study reveals that for temperatures above 250 eV, U serves as a better hohlraum material since it offers maximum re-emission for x-rays along with comparable mass ablation rate. Nevertheless, traditional choice, Au works well for temperatures below 250 eV. Besides inertial confinement fusion (ICF), the new scaling relations may find its application in view-factor codes, which generally ignore atomic physics calculations of opacities and emissivities, details of laser-plasma interaction and hydrodynamic motions.

Characterization of three small molecule inhibitors of enterovirus 71 identified from screening of a library of natural products.

PubMed

Li, Guiming; Gao, Qianqian; Yuan, Shilin; Wang, Lili; Altmeyer, Ralf; Lan, Ke; Yin, Feifei; Zou, Gang

2017-07-01

Enterovirus 71 (EV-A71) is a major cause of hand, foot, and mouth disease (HFMD). Infection with EV-A71 is more often associated with neurological complications in children and is responsible for the majority of fatalities, but currently there is no approved antiviral therapy for treatment. Here, we identified auraptene, formononetin, and yangonin as effective inhibitors of EV-A71 infection in the low-micromolar range from screening of a natural product library. Among them, formononetin and yangonin selectively inhibited EV-A71 while auraptene could inhibit viruses within the enterovirus species A. Time of addition studies showed that all the three inhibitors inhibit both attachment and postattachment step of entry. We found mutations conferring the resistance to these inhibitors in the VP1 and VP4 capsid proteins and confirmed the target residues using a reverse genetic approach. Interestingly, auraptene- and formononetin-resistant viruses exhibit cross-resistance to other inhibitors while yangonin-resistant virus still remains susceptible to auraptene and formononetin. Moreover, auraptene and formononetin, but not yangonin protected EV-A71 against thermal inactivation, indicating a direct stabilizing effect of both compounds on virion capsid conformation. Finally, neither biochanin A (an analog of formononetin) nor DL-Kavain (an analog of yangonin) exhibited anti-EV-A71 activity, suggesting the structural elements required for anti-EV-A71 activity. Taken together, these compounds could become potential lead compounds for anti-EV-A71 drug development and also serve as tool compounds for studying virus entry. Copyright © 2017 Elsevier B.V. All rights reserved.

Ribonucleic artefacts: are some extracellular RNA discoveries driven by cell culture medium components?

PubMed

Tosar, Juan Pablo; Cayota, Alfonso; Eitan, Erez; Halushka, Marc K; Witwer, Kenneth W

2017-01-01

In a recently published study, Anna Krichevsky and colleagues raise the important question of whether results of in vitro extracellular RNA (exRNA) studies, including extracellular vesicle (EV) investigations, are confounded by the presence of RNA in cell culture medium components such as foetal bovine serum (FBS). The answer, according to their data, is a resounding "yes". Even after lengthy ultracentrifugation to remove bovine EVs from FBS, the majority of exRNA in FBS remained. Although technical factors may affect the degree of depletion, residual EVs and exRNA in FBS could influence the conclusions of in vitro studies: certainly, for secreted RNA, and possibly also for cell-associated RNA. In this commentary, we critically examine some of the literature in this field, including a recent study from some of the authors of this piece, in light of the Wei et al. study and explore how cell culture-derived RNAs may affect what we think we know about EV RNAs. These findings hold particular consequence as the field moves towards a deeper understanding of EV-RNA associations and potential functions.

Building a Six-Junction Inverted Metamorphic Concentrator Solar Cell

DOE PAGES

Geisz, John F.; Steiner, Myles A.; Jain, Nikhil; ...

2017-12-20

We propose practical six-junction (6J) inverted metamorphic multijunction (IMM) concentrator solar cell designs with the potential to exceed 50% efficiency using moderately high quality junction materials. We demonstrate the top three junctions and their monolithic integration lattice matched to GaAs using 2.1-eV AlGaInP, 1.7-eV AlGaAs or GaInAsP, and 1.4-eV GaAs with external radiative efficiencies >0.1%. We demonstrate tunnel junctions with peak tunneling current >400 A/cm 2 that are transparent to <2.1-eV light. We compare the bottom three GaInAs(p) junctions with bandgaps of 1.2, 1.0, and 0.7 eV grown on InP and transparent metamorphic grades with low dislocation densities. The solutionmore » to an integration challenge resulting from Zn diffusion in the GaAs junction is illustrated in a five-junction IMM. Excellent 1-sun performance is demonstrated in a complete 6J IMM device with VOC = 5.15 V, and a promising pathway toward >50% efficiency at high concentrations is presented.« less

Building a Six-Junction Inverted Metamorphic Concentrator Solar Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geisz, John F.; Steiner, Myles A.; Jain, Nikhil

We propose practical six-junction (6J) inverted metamorphic multijunction (IMM) concentrator solar cell designs with the potential to exceed 50% efficiency using moderately high quality junction materials. We demonstrate the top three junctions and their monolithic integration lattice matched to GaAs using 2.1-eV AlGaInP, 1.7-eV AlGaAs or GaInAsP, and 1.4-eV GaAs with external radiative efficiencies >0.1%. We demonstrate tunnel junctions with peak tunneling current >400 A/cm 2 that are transparent to <2.1-eV light. We compare the bottom three GaInAs(p) junctions with bandgaps of 1.2, 1.0, and 0.7 eV grown on InP and transparent metamorphic grades with low dislocation densities. The solutionmore » to an integration challenge resulting from Zn diffusion in the GaAs junction is illustrated in a five-junction IMM. Excellent 1-sun performance is demonstrated in a complete 6J IMM device with VOC = 5.15 V, and a promising pathway toward >50% efficiency at high concentrations is presented.« less

A New Approach for Sustainable Energy Systems due to the Excitation of Inner-core Electrons on Zinc Atoms Induced by Surface-ion-recombination

NASA Astrophysics Data System (ADS)

Hamasaki, Mitsugi; Obara, Masumi; Yamaguchi, Mitsuomi; Kuwayama, Masahiro; Obara, Kozo

2011-12-01

The crisis of Nuclear power plants due to the March 11, 2011 Tsunami in Japan suggests an increased need for sustainable science and technology in our society. The authors propose a new physical approach with surface-ion-recombination (SIR) due to the inner-core excitation of zinc atom [Ne]3s23p63d104s2 that brings no magnetic moment. Condensed material indicated the energy dependence of X-ray diffraction intensity, in which exists strong diffuse scattering intensities at 10 eV, 90 eV, 100 eV and 230 eV. These energies are strictly corresponding to zinc of electron systems (3s,3p,3d and these combination). Our approach may have the potential of techniques for future nanotechnology, especially for hydrogen storage systems.

Conduction band offset at GeO{sub 2}/Ge interface determined by internal photoemission and charge-corrected x-ray photoelectron spectroscopies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, W. F.; Nishimula, T.; Nagashio, K.

2013-03-11

We report a consistent conduction band offset (CBO) at a GeO{sub 2}/Ge interface determined by internal photoemission spectroscopy (IPE) and charge-corrected X-ray photoelectron spectroscopy (XPS). IPE results showed that the CBO value was larger than 1.5 eV irrespective of metal electrode and substrate type variance, while an accurate determination of valence band offset (VBO) by XPS requires a careful correction of differential charging phenomena. The VBO value was determined to be 3.60 {+-} 0.2 eV by XPS after charge correction, thus yielding a CBO (1.60 {+-} 0.2 eV) in excellent agreement with the IPE results. Such a large CBO (>1.5more » eV) confirmed here is promising in terms of using GeO{sub 2} as a potential passivation layer for future Ge-based scaled CMOS devices.« less

Enhanced vision flight deck technology for commercial aircraft low-visibility surface operations

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J.; Norman, R. M.; Kramer, Lynda J.; Prinzel, Lawerence J.; Ellis, Kyle K.; Harrison, Stephanie J.; Comstock, J. R.

2013-05-01

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) airfield during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and minification effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

Enhanced Vision Flight Deck Technology for Commercial Aircraft Low-Visibility Surface Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Norman, R. Michael; Kramer, Lynda J.; Prinzel, Lawrence J., III; Ellis, Kyle K. E.; Harrison, Stephanie J.; Comstock, J. Ray

2013-01-01

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) air field during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and mini cation effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

Awareness and Detection of Traffic and Obstacles Using Synthetic and Enhanced Vision Systems

NASA Technical Reports Server (NTRS)

Bailey, Randall E.

2012-01-01

Research literature are reviewed and summarized to evaluate the awareness and detection of traffic and obstacles when using Synthetic Vision Systems (SVS) and Enhanced Vision Systems (EVS). The study identifies the critical issues influencing the time required, accuracy, and pilot workload associated with recognizing and reacting to potential collisions or conflicts with other aircraft, vehicles and obstructions during approach, landing, and surface operations. This work considers the effect of head-down display and head-up display implementations of SVS and EVS as well as the influence of single and dual pilot operations. The influences and strategies of adding traffic information and cockpit alerting with SVS and EVS were also included. Based on this review, a knowledge gap assessment was made with recommendations for ground and flight testing to fill these gaps and hence, promote the safe and effective implementation of SVS/EVS technologies for the Next Generation Air Transportation System

Modeling, Analysis, and Interpretation of Photoelectron Energy Spectra at Enceladus Observed by Cassini

NASA Astrophysics Data System (ADS)

Taylor, S. A.; Coates, A. J.; Jones, G. H.; Wellbrock, A.; Fazakerley, A. N.; Desai, R. T.; Caro-Carretero, R.; Michiko, M. W.; Schippers, P.; Waite, J. H.

2018-01-01

The Electron Spectrometer (ELS) of the Cassini Plasma Spectrometer has observed photoelectrons produced in the plume of Enceladus. These photoelectrons are observed during Enceladus encounters in the energetic particle shadow where the spacecraft is largely shielded from penetrating radiation by the moon. We present a complex electron spectrum at Enceladus including evidence of two previously unidentified electron populations at 6-10 eV and 10-16 eV. We estimate that the proportion of "hot" (>15 eV) to "cold" (<15 eV) electrons during the Enceladus flybys is ≈ 0.1-0.5%. We have constructed a model of photoelectron production in the plume and compared it with ELS Enceladus flyby data by scaling and energy shifting according to spacecraft potential. We suggest that the complex structure of the electron spectrum observed can be explained entirely by photoelectron production in the plume ionosphere.

Dynamics of Hollow Atom Formation in Intense X-Ray Pulses Probed by Partial Covariance Mapping

NASA Astrophysics Data System (ADS)

Frasinski, L. J.; Zhaunerchyk, V.; Mucke, M.; Squibb, R. J.; Siano, M.; Eland, J. H. D.; Linusson, P.; v. d. Meulen, P.; Salén, P.; Thomas, R. D.; Larsson, M.; Foucar, L.; Ullrich, J.; Motomura, K.; Mondal, S.; Ueda, K.; Osipov, T.; Fang, L.; Murphy, B. F.; Berrah, N.; Bostedt, C.; Bozek, J. D.; Schorb, S.; Messerschmidt, M.; Glownia, J. M.; Cryan, J. P.; Coffee, R. N.; Takahashi, O.; Wada, S.; Piancastelli, M. N.; Richter, R.; Prince, K. C.; Feifel, R.

2013-08-01

When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding the femtosecond dynamics of such systems is fundamental to achieving atomic resolution in flash diffraction imaging of noncrystallized complex biological samples. We demonstrate the capacity of a correlation method called “partial covariance mapping” to probe the electron dynamics of neon atoms exposed to intense 8 fs pulses of 1062 eV photons. A complete picture of ionization processes competing in hollow atom formation and decay is visualized with unprecedented ease and the map reveals hitherto unobserved nonlinear sequences of photoionization and Auger events. The technique is particularly well suited to the high counting rate inherent in FEL experiments.

Detection of wild-type EGFR amplification and EGFRvIII mutation in CSF-derived extracellular vesicles of glioblastoma patients.

PubMed

Figueroa, Javier M; Skog, Johan; Akers, Johnny; Li, Hongying; Komotar, Ricardo; Jensen, Randy; Ringel, Florian; Yang, Isaac; Kalkanis, Steven; Thompson, Reid; LoGuidice, Lori; Berghoff, Emily; Parsa, Andrew; Liau, Linda; Curry, William; Cahill, Daniel; Bettegowda, Chetan; Lang, Frederick F; Chiocca, E Antonio; Henson, John; Kim, Ryan; Breakefield, Xandra; Chen, Clark; Messer, Karen; Hochberg, Fred; Carter, Bob S

2017-10-19

RNAs within extracellular vesicles (EVs) have potential as diagnostic biomarkers for patients with cancer and are identified in a variety of biofluids. Glioblastomas (GBMs) release EVs containing RNA into cerebrospinal fluid (CSF). Here we describe a multi-institutional study of RNA extracted from CSF-derived EVs of GBM patients to detect the presence of tumor-associated amplifications and mutations in epidermal growth factor receptor (EGFR). CSF and matching tumor tissue were obtained from patients undergoing resection of GBMs. We determined wild-type (wt)EGFR DNA copy number amplification, as well as wtEGFR and EGFR variant (v)III RNA expression in tumor samples. We also characterized wtEGFR and EGFRvIII RNA expression in CSF-derived EVs. EGFRvIII-positive tumors had significantly greater wtEGFR DNA amplification (P = 0.02) and RNA expression (P = 0.03), and EGFRvIII-positive CSF-derived EVs had significantly more wtEGFR RNA expression (P = 0.004). EGFRvIII was detected in CSF-derived EVs for 14 of the 23 EGFRvIII tissue-positive GBM patients. Conversely, only one of the 48 EGFRvIII tissue-negative patients had the EGFRvIII mutation detected in their CSF-derived EVs. These results yield a sensitivity of 61% and a specificity of 98% for the utility of CSF-derived EVs to detect an EGFRvIII-positive GBM. Our results demonstrate CSF-derived EVs contain RNA signatures reflective of the underlying molecular genetic status of GBMs in terms of wtEGFR expression and EGFRvIII status. The high specificity of the CSF-derived EV diagnostic test gives us an accurate determination of positive EGFRvIII tumor status and is essentially a less invasive "liquid biopsy" that might direct mutation-specific therapies for GBMs. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Excitation Mechanisms in Moderate-Energy Li+-He Collisions

NASA Astrophysics Data System (ADS)

Kita, Shigetomo; Itaya, Jun; Sawatari, Yugo; Tabata, Tadanobu; Hayashi, Takeo; Shimakura, Noriyuki; Koseki, Shiro

2018-02-01

Excitation mechanisms in Li+-He collisions were studied at laboratory collision energies of 350 ≤ Elab ≤ 2000 eV by measuring double differential cross sections (DCSs) σ(Θ)k over a wide range of center-of-mass scattering angles, 2.5 ≤ Θ ≤ 175°. At Elab ≥ 500 eV, two-electron (2e) excitations were observed as well as one-electron (1e) excitations. At the higher collision energies, excitation probabilities P(Θ)k for the 1e and 2e excitations have characteristic angular dependences, i.e., at Elab = 1500 and 2000 eV, P(Θ)1e for the 1e excitations has double maxima around Θ = 20 and 120° and P(Θ)2e for the 2e excitations has a broad maximum around Θ = 60°. As a first analysis of the experimental data, P(Θ)k, σ(Θ)k, and the integral cross sections Sk(Elab) were calculated by assuming excitations from the 11Σ state into the 11Π and 11Δ states through rotational couplings using the model potentials and couplings. As the next step, ab initio potential energies for the ground and excited states were calculated by a multiconfiguration self-consistent field (MCSCF) method, and then the electronic transitions among the seven states through the radial and rotational couplings were calculated using the theoretical potentials and couplings. Autoionizations from the 2e-excited He**(2s2 and 2p2) atoms were also simulated at Elab = 750-1500 eV and small laboratory angles of θ ≤ 25° by using the MCSCF potentials. The excitation mechanisms were reasonably well understood through these analyses.

Investigation of electronic structures and optical properties of β -Si3N4 doped with IV A elements: A first-principles simulation

NASA Astrophysics Data System (ADS)

Lu, Xuefeng; Gao, Xu; Ren, Junqiang; Li, Cuixia; Guo, Xin; Wei, Yupeng; La, Peiqing

2018-04-01

Based on first-principles simulations with the generalized gradient approximation (GGA) of the Perdew-Burke-Ernzerhof (PBE) functional, we studied the electronic structures and optical properties of hexagonal silicon nitride (β-Si3N4) doped with IV A elements, C, Ge, Sn and Pb. It was found that the Ge-doped system is characterized by a more stable structure with a lower formation energy of 2.584 eV compared with those of the C-, Sn- and Pb-doped systems of 3.877 eV, 5.249 eV and 7.672 eV, respectively. The band gap (EG) of the Pb-doped system was the lowest at 1.6 eV, displaying semiconducting characteristics. Additionally, there was a transition from a direct band gap to an indirect band gap in the C-doped system. Charge difference density analysis showed that the covalent property of the C-N bonds was enhanced by expansion of the electron-free region and the larger Mulliken population values of 0.71 and 0.86. Furthermore, lower absorption and reflectivity peaks at 11.30 eV were observed for the C-doped system, demonstrating its broader potential for application in photoelectric and microelectronic devices.

Evidence-Based Clinical Use of Nanoscale Extracellular Vesicles in Nanomedicine.

PubMed

Fais, Stefano; O'Driscoll, Lorraine; Borras, Francesc E; Buzas, Edit; Camussi, Giovanni; Cappello, Francesco; Carvalho, Joana; Cordeiro da Silva, Anabela; Del Portillo, Hernando; El Andaloussi, Samir; Ficko Trček, Tanja; Furlan, Roberto; Hendrix, An; Gursel, Ihsan; Kralj-Iglic, Veronika; Kaeffer, Bertrand; Kosanovic, Maja; Lekka, Marilena E; Lipps, Georg; Logozzi, Mariantonia; Marcilla, Antonio; Sammar, Marei; Llorente, Alicia; Nazarenko, Irina; Oliveira, Carla; Pocsfalvi, Gabriella; Rajendran, Lawrence; Raposo, Graça; Rohde, Eva; Siljander, Pia; van Niel, Guillaume; Vasconcelos, M Helena; Yáñez-Mó, María; Yliperttula, Marjo L; Zarovni, Natasa; Zavec, Apolonija Bedina; Giebel, Bernd

2016-04-26

Recent research has demonstrated that all body fluids assessed contain substantial amounts of vesicles that range in size from 30 to 1000 nm and that are surrounded by phospholipid membranes containing different membrane microdomains such as lipid rafts and caveolae. The most prominent representatives of these so-called extracellular vesicles (EVs) are nanosized exosomes (70-150 nm), which are derivatives of the endosomal system, and microvesicles (100-1000 nm), which are produced by outward budding of the plasma membrane. Nanosized EVs are released by almost all cell types and mediate targeted intercellular communication under physiological and pathophysiological conditions. Containing cell-type-specific signatures, EVs have been proposed as biomarkers in a variety of diseases. Furthermore, according to their physical functions, EVs of selected cell types have been used as therapeutic agents in immune therapy, vaccination trials, regenerative medicine, and drug delivery. Undoubtedly, the rapidly emerging field of basic and applied EV research will significantly influence the biomedicinal landscape in the future. In this Perspective, we, a network of European scientists from clinical, academic, and industry settings collaborating through the H2020 European Cooperation in Science and Technology (COST) program European Network on Microvesicles and Exosomes in Health and Disease (ME-HAD), demonstrate the high potential of nanosized EVs for both diagnostic and therapeutic (i.e., theranostic) areas of nanomedicine.

Effect of secondary electron emission on the plasma sheath

NASA Astrophysics Data System (ADS)

Langendorf, S.; Walker, M.

2015-03-01

In this experiment, plasma sheath potential profiles are measured over boron nitride walls in argon plasma and the effect of secondary electron emission is observed. Results are compared to a kinetic model. Plasmas are generated with a number density of 3 × 1012 m-3 at a pressure of 10-4 Torr-Ar, with a 1%-16% fraction of energetic primary electrons. The sheath potential profile at the surface of each sample is measured with emissive probes. The electron number densities and temperatures are measured in the bulk plasma with a planar Langmuir probe. The plasma is non-Maxwellian, with isotropic and directed energetic electron populations from 50 to 200 eV and hot and cold Maxwellian populations from 3.6 to 6.4 eV and 0.3 to 1.3 eV, respectively. Plasma Debye lengths range from 4 to 7 mm and the ion-neutral mean free path is 0.8 m. Sheath thicknesses range from 20 to 50 mm, with the smaller thickness occurring near the critical secondary electron emission yield of the wall material. Measured floating potentials are within 16% of model predictions. Measured sheath potential profiles agree with model predictions within 5 V (˜1 Te), and in four out of six cases deviate less than the measurement uncertainty of 1 V.

High Mobility Conjugated Polymers

DTIC Science & Technology

2007-10-20

will act as a trap for opposite charge carriers; the electron affinities were 4.0 eV (BBL) and 2.7 eV (PTHQx) and ionization potentials were 6.0 eV...transistors (OFETs), photovoltaic cells, and photodetectors, is limited primarily by the low charge carrier mobilities of current materials. To address this...showing a maximum mobility with hexyl. Fundamental insights into the structural factors that govern high mobility charge transport and recombination in

Stability and carrier transport properties of phosphorene-based polymorphic nanoribbons

NASA Astrophysics Data System (ADS)

Kaur, Sumandeep; Kumar, Ashok; Srivastava, Sunita; Pandey, Ravindra; Tankeshwar, K.

2018-04-01

Few-layer black phosphorene has recently attracted significant interest in the scientific community. In this paper, we consider several polymorphs of phosphorene nanoribbons (PNRs) and employ deformation potential theory within the effective mass approximation, together with density functional theory, to investigate their structural, mechanical and electronic properties. The results show that the stability of a PNR strongly depends on the direction along which it can be cut from its 2D counterpart. PNRs also exhibit a wide range of line stiffnesses ranging from 6 × 1010 eV m-1 to 18 × 1011 eV m-1, which has little dependence on the edge passivation. Likewise, the calculated electronic properties of PNRs show them to be either a narrow-gap semiconductor (E g < 1 eV) or a wide-gap semiconductor (E g > 1 eV). The carrier mobility of PNRs is found to be comparable to that of black phosphorene. Some of the PNRs show an n-type (p-type) semiconducting character owing to their higher electron (hole) mobility. Passivation of the edges leads to n-type ↔ p-type transition in many of the PNRs considered. The predicted novel characteristics of PNRs, with a wide range of mechanical and electronic properties, make them potentially suitable for use in nanoscale devices.

Mechanism and kinetics of the electrocatalytic reaction responsible for the high cost of hydrogen fuel cells.

PubMed

Cheng, Tao; Goddard, William A; An, Qi; Xiao, Hai; Merinov, Boris; Morozov, Sergey

2017-01-25

The sluggish oxygen reduction reaction (ORR) is a major impediment to the economic use of hydrogen fuel cells in transportation. In this work, we report the full ORR reaction mechanism for Pt(111) based on Quantum Mechanics (QM) based Reactive metadynamics (RμD) simulations including explicit water to obtain free energy reaction barriers at 298 K. The lowest energy pathway for 4 e - water formation is: first, *OOH formation; second, *OOH reduction to H 2 O and O*; third, O* hydrolysis using surface water to produce two *OH and finally *OH hydration to water. Water formation is the rate-determining step (RDS) for potentials above 0.87 Volt, the normal operating range. Considering the Eley-Rideal (ER) mechanism involving protons from the solvent, we predict the free energy reaction barrier at 298 K for water formation to be 0.25 eV for an external potential below U = 0.87 V and 0.41 eV at U = 1.23 V, in good agreement with experimental values of 0.22 eV and 0.44 eV, respectively. With the mechanism now fully understood, we can use this now validated methodology to examine the changes upon alloying and surface modifications to increase the rate by reducing the barrier for water formation.

A comparative study of the Au + H{sub 2}, Au{sup +} + H{sub 2}, and Au{sup −} + H{sub 2} systems: Potential energy surfaces and dynamics of reactive collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorta-Urra, Anaís; Zanchet, Alexandre; Roncero, Octavio

2015-04-21

In order to study the Au{sup −} + H{sub 2} collision, a new global potential energy surface (PES) describing the ground electronic state of AuH{sub 2}{sup −} system is developed and compared with the PESs of the neutral [Zanchet et al., J. Chem. Phys. 132, 034301 (2010)] and cationic systems [Anaís et al., J. Chem. Phys. 135, 091102 (2011)]. We found that Au{sup −} − H{sub 2} presents a H-Au-H insertion minimum attributed to the stabilization of the LUMO 3b{sub 2} orbital, which can be considered as the preamble of the chemisorption well appearing in larger gold clusters. While themore » LUMO orbital is stabilized, the HOMO 6a{sub 1} is destabilized, creating a barrier at the geometry where the energy orbitals’ curves are crossing. In the anion, this HOMO is doubly occupied, while in the neutral system is half-filled and completely empty in the cation, explaining the gradual disappearance of the well and the barrier as the number of electrons decreases. The cation presents a well in the entrance channel partially explained by electrostatic interactions. The three systems’ reactions are highly endothermic, by 1.66, 2.79, and 3.23 eV for AuH, AuH{sup +}, and AuH{sup −} products, respectively. The reaction dynamics is studied using quasi-classical trajectory method for the three systems. The one corresponding to the anionic system is new in this work. Collision energies between 1.00 and 8.00 eV, measured for the cation, are in good agreement with the simulated cross section for the AuH{sup +}. It was also found that the total fragmentation, in three atoms, competes becoming dominant at sufficiently high energy. Here, we study the competition between the two different reaction pathways for the anionic, cationic, and neutral species, explaining the differences using a simple model based on the topology of the potential energy surfaces.« less

Fast Charging Electric Vehicle Research & Development Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heny, Michael

The research and development project supported the engineering, design and implementation of on-road Electric Vehicle (“EV”) charging technologies. It included development of potential solutions for DC fast chargers (“DCFC”) capable of converting high voltage AC power to the DC power required by EVs. Additional development evaluated solutions related to the packaging of power electronic components and enclosure design, as well as for the design and evaluation of EV charging stations. Research compared different charging technologies to identify optimum applications in a municipal fleet. This project collected EV usage data and generated a report demonstrating that EVs, when supported by adequatemore » charging infrastructure, are capable of replacing traditional internal combustion vehicles in many municipal applications. The project’s period of performance has demonstrated various methods of incorporating EVs into a municipal environment, and has identified three general categories for EV applications: Short Commute: Defined as EVs performing in limited duration, routine commutes. - Long Commute: Defined as tasks that require EVs to operate in longer daily mileage patterns. - Critical Needs: Defined as the need for EVs to be ready at every moment for indefinite periods. Together, the City of Charlottesville, VA (the “City”) and Aker Wade Power Technologies, LLC (“Aker Wade”) concluded that the EV has a viable position in many municipal fleets but with limited recommendation for use in Critical Needs applications such as Police fleets. The report also documented that, compared to internal combustion vehicles, BEVs have lower vehicle-related greenhouse gas (“GHG”) emissions and contribute to a reduction of air pollution in urban areas. The enhanced integration of EVs in a municipal fleet can result in reduced demand for imported oil and reduced municipal operating costs. The conclusions indicated in the project’s Engineering Report (see Attachment A) are intended to assist future implementation of electric vehicle technology. They are based on the cited research and on the empirical data collected and presented. The report is not expected to represent the entire operating conditions of any of the equipment under consideration within this project, and tested equipment may operate differently under other conditions.« less

Microfluidic Approaches for Isolation, Detection, and Characterization of Extracellular Vesicles: Current Status and Future Directions

PubMed Central

Gholizadeh, Shima; Draz, Mohamed; Zarghooni, Maryam; Nezhad, Amir Sanati; Ghavami, Saeid; Shafiee, Hadi; Akbari, Mohsen

2017-01-01

Extracellular vesicles (EVs) are cell-derived vesicles present in body fluids that play an essential role in various cellular processes, such as intercellular communication, inflammation, cellular homeostasis, survival, transport, and regeneration. Their isolation and analysis from body fluids have a great clinical potential to provide information on a variety of disease states such as cancer, cardiovascular complication and inflammatory disorders. Despite increasing scientific and clinical interest in this field, at the time of writing there are still no standardized procedures available for the purification, detection, and characterization of EVs. Advances in microfluidics allow for chemical sampling with increasingly high spatial resolution and under precise manipulation down to single molecule level. In this review, our objective is to give a brief overview on the working principle and examples of the isolation and detection methods with the potential to be used for extracellular vesicles. This review will also highlight the integrated on-chip systems for isolation and characterization of EVs. PMID:28088752

Shape resonances of Be- and Mg- investigated with the method of analytic continuation

NASA Astrophysics Data System (ADS)

Čurík, Roman; Paidarová, I.; Horáček, J.

2018-05-01

The regularized method of analytic continuation is used to study the low-energy negative-ion states of beryllium (configuration 2 s2ɛ p 2P ) and magnesium (configuration 3 s2ɛ p 2P ) atoms. The method applies an additional perturbation potential and requires only routine bound-state multi-electron quantum calculations. Such computations are accessible by most of the free or commercial quantum chemistry software available for atoms and molecules. The perturbation potential is implemented as a spherical Gaussian function with a fixed width. Stability of the analytic continuation technique with respect to the width and with respect to the input range of electron affinities is studied in detail. The computed resonance parameters Er=0.282 eV, Γ =0.316 eV for the 2 p state of Be- and Er=0.188 eV, Γ =0.167 for the 3 p state of Mg- agree well with the best results obtained by much more elaborate and computationally demanding present-day methods.

A booster dose of an inactivated enterovirus 71 vaccine in chinese young children: a randomized, double-blind, placebo-controlled clinical trial.

PubMed

Shenyu, Wang; Jingxin, Li; Zhenglun, Liang; Xiuling, Li; Qunying, Mao; Fanyue, Meng; Hua, Wang; Yuntao, Zhang; Fan, Gao; Qinghua, Chen; Yuemei, Hu; Xin, Yao; Huijie, Guo; Fengcai, Zhu

2014-10-01

A significant waning of enterovirus 71 (EV71) antibody titer after priming immunization with an inactivated EV71 vaccine implied the potential need for a booster dose. In this randomized, double-blind, placebo-controlled clinical trial, we recruited participants who had received at least 1 dose of priming EV71 vaccine in an early phase 2 clinical trial that was conducted in healthy infants and children aged 6-35 months. All participants were grouped according to the priming EV71 vaccine formulations (160 U, 320 U, and 640 U with adjuvant and 640 U without adjuvant) and then randomly assigned (ratio, 2:1) to receive a booster dose of vaccine or placebo within each formulation group. The primary end point was the geometric mean titer 28 days after the booster dose. A total of 773 participants were enrolled. Significantly greater immunological responses were induced by the booster shot of all 4 formulations of EV71 vaccine, compared with that induced by placebo (P < .0001). The frequencies of adverse reactions were similar between vaccine and placebo groups within each formulation group. A booster dose of EV71 vaccine 1 year after the priming EV71 immunization shows excellent immunogenicity and good safety profile. Clinical Trials Registration: NCT01734408. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Pros and cons of VP1-specific maternal IgG for the protection of Enterovirus 71 infection.

PubMed

Kim, Young-In; Song, Jae-Hyoung; Kwon, Bo-Eun; Kim, Ha-Neul; Seo, Min-Duk; Park, KwiSung; Lee, SangWon; Yeo, Sang-Gu; Kweon, Mi-Na; Ko, Hyun-Jeong; Chang, Sun-Young

2015-11-27

Enterovirus 71 (EV71) causes hand, foot, and mouth diseases and can result in severe neurological disorders when it infects the central nervous system. Thus, there is a need for the development of effective vaccines against EV71 infection. Here we report that viral capsid protein 1 (VP1), one of the main capsid proteins of EV71, efficiently elicited VP1-specific immunoglobulin G (IgG) in the serum of mice immunized with recombinant VP1. The VP1-specific IgG produced in female mice was efficiently transferred to their offspring, conferring protection against EV71 infection immediately after birth. VP1-specific antibody can neutralize EV71 infection and protect host cells. VP1-specific maternal IgG in offspring was maintained for over 6 months. However, the pre-existence of VP1-specific maternal IgG interfered with the production of VP1-specific IgG antibody secreting cells by active immunization in offspring. Therefore, although our results showed the potential for VP1-specific maternal IgG protection against EV71 in neonatal mice, other strategies must be developed to overcome the hindrance of maternal IgG in active immunization. In this study, we developed an effective and feasible animal model to evaluate the protective efficacy of humoral immunity against EV71 infection using a maternal immunity concept. Copyright © 2015 Elsevier Ltd. All rights reserved.

Expression and immunogenicity of novel subunit enterovirus 71 VP1 antigens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Juan; Department of Microbiology and Immunology, Nanjing Medical University; Wang, Shixia

Highlights: Black-Right-Pointing-Pointer EV71 is a major emerging infectious disease in many Asian countries. Black-Right-Pointing-Pointer Inactivated EV71 vaccines are in clinical studies but their safety and efficacy are unknown. Black-Right-Pointing-Pointer Developing subunit based EV71 vaccines is significant and novel antigen design is needed. Black-Right-Pointing-Pointer DNA immunization is an efficient tool to test the immunogenicity of VP1 based EV71 vaccines. Black-Right-Pointing-Pointer Multiple VP1 antigens are developed showing immunogenic potential. -- Abstract: Hand, foot, and mouth disease (HFMD) is a common viral illness in young children. HFMD is caused by viruses belonging to the enterovirus genus of the picornavirus family. Recently, enterovirus 71more » (EV71) has emerged as a virulent agent for HFMD with severe clinical outcomes. In the current report, we conducted a pilot antigen engineering study to optimize the expression and immunogenicity of subunit VP1 antigen for the design of EV71 vaccines. DNA immunization was adopted as a simple technical approach to test different designs of VP1 antigens without the need to express VP1 protein in vitro first. Our studies indicated that the expression and immunogenicity of VP1 protein can be improved with alternated VP1 antigen designs. Data presented in the current report revealed novel pathways to optimize the design of VP1 antigen-based EV71 vaccines.« less

Structural and optical properties of AgIn5S8

NASA Astrophysics Data System (ADS)

Rincón, Carlos A. Durante; Durán, Larissa T.; Medina, Josefa Estévez; Castro, Jaime A.; León, Máximo; Fermín, Jose R.

2017-12-01

Compounds of the chalcogenide family Ag-In-VI (VI = S, Se, Te) are interesting materials due to their stoichiometric stability and potential application in nonlinear optics and solar cells. A polycrystalline ingot of AgIn5S8, an ordered vacancy semiconductor, was prepared by direct fusion of the stoichiometric mixture of the elements in an evacuated quartz ampoule. The presence of a single phase with cubic structure was confirmed by X-ray powder diffraction at room temperature. The lattice parameter, a, was calculated, giving 10.821750 Å. Samples in evacuated quartz ampoules were used to perform Differential Thermal Analysis measurements, showing congruent melting at 1110∘C. Transmittance and reflectivity measurements were used to calculate the absorption coefficient α. From the plot of (αhν)2 versus hν, two direct transitions are observed at 1.25 eV and 1.88 eV. While the higher energy direct transition has been observed by other authors, the direct nature of the lower energy transition was confirmed from the fitting of the plot of the reflectivity versus 1/hν between 0.53 eV-1 (1.89 eV) and 0.55 eV-1 (1.82 eV), obtaining a value of 1.29 eV. The real refractive index n and the high-frequency dielectric constant 𝜀∞ were also obtained from the fit of the reflectivity, resulting to be 2.68 and 7.2, respectively.

Low-lying electronic states of Li 2+ and Li 2-

NASA Astrophysics Data System (ADS)

Konowalow, Daniel D.; Fish, James L.

1984-02-01

Potential curves for the eight lowest lying electronic states of Li2+ and the two lowest-lying states of Li2- are obtained by valence configuration calculations which-utilize an effective core potential. The calculated ionization potential of the ground state of Li2 is found to b. 5.16 eV and its electron affinity is 0.429 eV. Both values are in excellent agreement with recent experimental values and with value deduced from other high quality ab initio quantum mechanical treatments. When our potential curve for the Li2+(12Σg+ state, is corrected for the core-valence correlation error we obtain spectroscopic constants which agree nicely with the experimental values of Bernheim, Gold and Tipton (BGT). For example, we findDe = 10460 ± 140 cm-1 while BGT reportDe = 10469 ± 6 cm-1.

Study of Li atom diffusion in amorphous Li3PO4 with neural network potential

NASA Astrophysics Data System (ADS)

Li, Wenwen; Ando, Yasunobu; Minamitani, Emi; Watanabe, Satoshi

2017-12-01

To clarify atomic diffusion in amorphous materials, which is important in novel information and energy devices, theoretical methods having both reliability and computational speed are eagerly anticipated. In the present study, we applied neural network (NN) potentials, a recently developed machine learning technique, to the study of atom diffusion in amorphous materials, using Li3PO4 as a benchmark material. The NN potential was used together with the nudged elastic band, kinetic Monte Carlo, and molecular dynamics methods to characterize Li vacancy diffusion behavior in the amorphous Li3PO4 model. By comparing these results with corresponding DFT calculations, we found that the average error of the NN potential is 0.048 eV in calculating energy barriers of diffusion paths, and 0.041 eV in diffusion activation energy. Moreover, the diffusion coefficients obtained from molecular dynamics are always consistent with those from ab initio molecular dynamics simulation, while the computation speed of the NN potential is 3-4 orders of magnitude faster than DFT. Lastly, the structure of amorphous Li3PO4 and the ion transport properties in it were studied with the NN potential using a large supercell model containing more than 1000 atoms. The formation of P2O7 units was observed, which is consistent with the experimental characterization. The Li diffusion activation energy was estimated to be 0.55 eV, which agrees well with the experimental measurements.

NANOWIRE CATHODE MATERIAL FOR LITHIUM-ION BATTERIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

John Olson, PhD

2004-07-21

This project involved the synthesis of nanowire ã-MnO2 and characterization as cathode material for high-power lithium-ion batteries for EV and HEV applications. The nanowire synthesis involved the edge site decoration nanowire synthesis developed by Dr. Reginald Penner at UC Irvine (a key collaborator in this project). Figure 1 is an SEM image showing ã-MnO2 nanowires electrodeposited on highly oriented pyrolytic graphite (HOPG) electrodes. This technique is unique to other nanowire template synthesis techniques in that it produces long (>500 um) nanowires which could reduce or eliminate the need for conductive additives due to intertwining of fibers. Nanowire cathode for lithium-ionmore » batteries with surface areas 100 times greater than conventional materials can enable higher power batteries for electric vehicles (EVs) and hybrid electric vehicles (HEVs). The synthesis of the ã-MnO2 nanowires was successfully achieved. However, it was not found possible to co-intercalate lithium directly in the nanowire synthesis. Based on input from proposal reviewers, the scope of the project was altered to attempt the conversion into spinel LiMn2O4 nanowire cathode material by solid state reaction of the ã-MnO2 nanowires with LiNO3 at elevated temperatures. Attempts to perform the conversion on the graphite template were unsuccessful due to degradation of the graphite apparently caused by oxidative attack by LiNO3. Emphasis then shifted to quantitative removal of the nanowires from the graphite, followed by the solid state reaction. Attempts to quantitatively remove the nanowires by several techniques were unsatisfactory due to co-removal of excess graphite or poor harvesting of nanowires. Intercalation of lithium into ã-MnO2 electrodeposited onto graphite was demonstrated, showing a partial demonstration of the ã-MnO2 material as a lithium-ion battery cathode material. Assuming the issues of nanowires removal can be solved, the technique does offer potential for creating high-power lithium-ion battery cathode needed for advanced EV and HEVs. Several technical advancements will still be required to meet this goal, and are likely topics for future SBIR feasibility studies.« less

Large Work Function Modulation of Monolayer MoS2 by Ambient Gases.

PubMed

Lee, Si Young; Kim, Un Jeong; Chung, JaeGwan; Nam, Honggi; Jeong, Hye Yun; Han, Gang Hee; Kim, Hyun; Oh, Hye Min; Lee, Hyangsook; Kim, Hyochul; Roh, Young-Geun; Kim, Jineun; Hwang, Sung Woo; Park, Yeonsang; Lee, Young Hee

2016-06-28

Although two-dimensional monolayer transition-metal dichalcogenides reveal numerous unique features that are inaccessible in bulk materials, their intrinsic properties are often obscured by environmental effects. Among them, work function, which is the energy required to extract an electron from a material to vacuum, is one critical parameter in electronic/optoelectronic devices. Here, we report a large work function modulation in MoS2 via ambient gases. The work function was measured by an in situ Kelvin probe technique and further confirmed by ultraviolet photoemission spectroscopy and theoretical calculations. A measured work function of 4.04 eV in vacuum was converted to 4.47 eV with O2 exposure, which is comparable with a large variation in graphene. The homojunction diode by partially passivating a transistor reveals an ideal junction with an ideality factor of almost one and perfect electrical reversibility. The estimated depletion width obtained from photocurrent mapping was ∼200 nm, which is much narrower than bulk semiconductors.

Fermi energy control of vacancy coalescence and dislocation density in melt-grown GaAs

NASA Technical Reports Server (NTRS)

Lagowski, J.; Gatos, H. C.; Lin, D. G.; Aoyama, T.

1984-01-01

A striking effect of the Fermi energy on the dislocation density in melt-grown GaAs has been discovered. Thus, a shift of the Fermi energy from 0.1 eV above to 0.2 eV below its intrinsic value (at high temperature, i.e., near 1100 K) increases the dislocation density by as much as five orders of magnitude. The Fermi energy shift was brought about by n-type and p-type doping at a level of about 10 to the 17th per cu cm (under conditions of optimum partial pressure of As, i.e., under optimum melt stoichiometry). This effect must be associated with the fact that the Fermi energy controls the charge state of vacancies (i.e., the occupancy of the associated electronic states) which in turn must control their tendency to coalesce and thus the dislocation density. It appears most likely that gallium vacancies are the critical species.

Presence of Cx43 in extracellular vesicles reduces the cardiotoxicity of the anti-tumour therapeutic approach with doxorubicin

PubMed Central

Martins-Marques, Tania; Pinho, Maria Joao; Zuzarte, Monica; Oliveira, Carla; Pereira, Paulo; Sluijter, Joost P. G.; Gomes, Celia; Girao, Henrique

2016-01-01

Extracellular vesicles (EVs) are major conveyors of biological information, mediating local and systemic cell-to-cell communication under physiological and pathological conditions. These endogenous vesicles have been recognized as prominent drug delivery vehicles of several therapeutic cargoes, including doxorubicin (dox), presenting major advantages over the classical approaches. Although dox is one of the most effective anti-tumour agents in the clinical practice, its use is very often hindered by its consequent dramatic cardiotoxicity. Despite significant advances witnessed in the past few years, more comprehensive studies, supporting the therapeutic efficacy of EVs, with decreased side effects, are still scarce. The main objective of this study was to evaluate the role of the gap junction protein connexin43 (Cx43) in mediating the release of EV content into tumour cells. Moreover, we investigated whether Cx43 improves the efficiency of dox-based anti-tumour treatment, with a concomitant decrease of cardiotoxicity. In the present report, we demonstrate that the presence of Cx43 in EVs increases the release of luciferin from EVs into tumour cells in vitro and in vivo. In addition, using cell-based approaches and a subcutaneous mouse tumour model, we show that the anti-tumour effect of dox incorporated into EVs is similar to the administration of the free drug, regardless the presence of Cx43. Strikingly, we demonstrate that the presence of Cx43 in dox-loaded EVs reduces the cardiotoxicity of the drug. Altogether, these results bring new insights into the concrete potential of EVs as therapeutic vehicles and open new avenues toward the development of strategies that help to reduce unwanted side effects. PMID:27702427

Implication of the solvent effect, metal ions and topology in the electronic structure and hydrogen bonding of human telomeric G-quadruplex DNA.

PubMed

Poudel, Lokendra; Steinmetz, Nicole F; French, Roger H; Parsegian, V Adrian; Podgornik, Rudolf; Ching, Wai-Yim

2016-08-03

We present a first-principles density functional study elucidating the effects of solvent, metal ions and topology on the electronic structure and hydrogen bonding of 12 well-designed three dimensional G-quadruplex (G4-DNA) models in different environments. Our study shows that the parallel strand structures are more stable in dry environments and aqueous solutions containing K(+) ions within the tetrad of guanine but conversely, that the anti-parallel structure is more stable in solutions containing the Na(+) ions within the tetrad of guanine. The presence of metal ions within the tetrad of the guanine channel always enhances the stability of the G4-DNA models. The parallel strand structures have larger HOMO-LUMO gaps than antiparallel structures, which are in the range of 0.98 eV to 3.11 eV. Partial charge calculations show that sugar and alkali ions are positively charged whereas nucleobases, PO4 groups and water molecules are all negatively charged. Partial charges on each functional group with different signs and magnitudes contribute differently to the electrostatic interactions involving G4-DNA and favor the parallel structure. A comparative study between specific pairs of different G4-DNA models shows that the Hoogsteen OH and NH hydrogen bonds in the guanine tetrad are significantly influenced by the presence of metal ions and water molecules, collectively affecting the structure and the stability of G4-DNA.

Partial cross sections of helium satellites at medium photon energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wehlitz, R.; Sellin, I.A.; Hemmers, O.

1997-04-01

Still of current interest is the important role of single ionization with excitation compared to single ionization alone. The coupling between the electrons and the incoming photon is a single-particle operator. Thus, an excitation in addition to an ionization, leading to a so-called satellite line in a photoelectron spectrum, is entirely due to electron-electron interaction and probes the electron correlation in the ground and final state. Therefore the authors have undertaken the study of the intensity of helium satellites He{sup +}nl (n = 2 - 6) relative to the main photoline (n = 1) as a function of photon energymore » at photon energies well above threshold up to 900 eV. From these results they could calculate the partial cross-sections of the helium satellites. In order to test the consistency of their satellite-to-1s ratios with published double-to-single photoionization ratios, the authors calculated the double-to-single photoionization ratio from their measured ratios using the theoretical energy-distribution curves of Chang and Poe and Le Rouzo and Dal Cappello which proved to be valid for photon energies below 120 eV. These calculated double-to-single ionization ratios agree fairly well with recent ion measurements. In the lower photon energy range the authors ratios agree better with the ratios of Doerner et al. while for higher photon energies the agreement is better with the values of Levin et al.« less

Mesenchymal stromal cell-derived extracellular vesicles attenuate lung ischemia-reperfusion injury and enhance reconditioning of donor lungs after circulatory death.

PubMed

Stone, Matthew L; Zhao, Yunge; Robert Smith, J; Weiss, Mark L; Kron, Irving L; Laubach, Victor E; Sharma, Ashish K

2017-12-21

Lung ischemia-reperfusion (IR) injury after transplantation as well as acute shortage of suitable donor lungs are two critical issues impacting lung transplant patients. This study investigates the anti-inflammatory and immunomodulatory role of human mesenchymal stromal cells (MSCs) and MSC-derived extracellular vesicles (EVs) to attenuate lung IR injury and improve of ex-vivo lung perfusion (EVLP)-mediated rehabilitation in donation after circulatory death (DCD) lungs. C57BL/6 wild-type (WT) mice underwent sham surgery or lung IR using an in vivo hilar-ligation model with or without MSCs or EVs. In vitro studies used primary iNKT cells and macrophages (MH-S cells) were exposed to hypoxia/reoxygenation with/without co-cultures with MSCs or EVs. Also, separate groups of WT mice underwent euthanasia and 1 h of warm ischemia and stored at 4 °C for 1 h followed by 1 h of normothermic EVLP using Steen solution or Steen solution containing MSCs or EVs. Lungs from MSCs or EV-treated mice had significant attenuation of lung dysfunction and injury (decreased edema, neutrophil infiltration and myeloperoxidase levels) compared to IR alone. A significant decrease in proinflammatory cytokines (IL-17, TNF-α, CXCL1 and HMGB1) and upregulation of keratinocyte growth factor, prostaglandin E2 and IL-10 occurred in the BAL fluid from MSC or EV-treated mice after IR compared to IR alone. Furthermore, MSCs or EVs significantly downregulated iNKT cell-produced IL-17 and macrophage-produced HMGB1 and TNF-α after hypoxia/reoxygenation. Finally, EVLP of DCD lungs with Steen solution including MSCs or EVs provided significantly enhanced protection versus Steen solution alone. Co-cultures of MSCs or EVs with lung endothelial cells prevents neutrophil transendothelial migration after exposure to hypoxia/reoxygenation and TNF-α/HMGB1 cytomix. These results suggest that MSC-derived EVs can attenuate lung inflammation and injury after IR as well as enhance EVLP-mediated reconditioning of donor lungs. The therapeutic benefits of EVs are in part mediated through anti-inflammatory promoting mechanisms via attenuation of immune cell activation as well as prevention of endothelial barrier integrity to prevent lung edema. Therefore, MSC-derived EVs offer a potential therapeutic strategy to treat post-transplant IR injury as well as rehabilitation of DCD lungs.

Systematic variation in the temperature dependence of physiological and ecological traits.

PubMed

Dell, Anthony I; Pawar, Samraat; Savage, Van M

2011-06-28

To understand the effects of temperature on biological systems, we compile, organize, and analyze a database of 1,072 thermal responses for microbes, plants, and animals. The unprecedented diversity of traits (n = 112), species (n = 309), body sizes (15 orders of magnitude), and habitats (all major biomes) in our database allows us to quantify novel features of the temperature response of biological traits. In particular, analysis of the rising component of within-species (intraspecific) responses reveals that 87% are fit well by the Boltzmann-Arrhenius model. The mean activation energy for these rises is 0.66 ± 0.05 eV, similar to the reported across-species (interspecific) value of 0.65 eV. However, systematic variation in the distribution of rise activation energies is evident, including previously unrecognized right skewness around a median of 0.55 eV. This skewness exists across levels of organization, taxa, trophic groups, and habitats, and it is partially explained by prey having increased trait performance at lower temperatures relative to predators, suggesting a thermal version of the life-dinner principle-stronger selection on running for your life than running for your dinner. For unimodal responses, habitat (marine, freshwater, and terrestrial) largely explains the mean temperature at which trait values are optimal but not variation around the mean. The distribution of activation energies for trait falls has a mean of 1.15 ± 0.39 eV (significantly higher than rises) and is also right-skewed. Our results highlight generalities and deviations in the thermal response of biological traits and help to provide a basis to predict better how biological systems, from cells to communities, respond to temperature change.

First-principles calculation of adsorption of shale gas on CaCO3 (100) surfaces.

PubMed

Luo, Qiang; Pan, Yikun; Guo, Ping; Wang, Zhouhua; Wei, Na; Sun, Pengfei; Liu, Yuxiao

2017-06-16

To demonstrate the adsorption strength of shale gas to calcium carbonate in shale matrix, the adsorption of shale gas on CaCO3 (100) surfaces was studied using the first-principles method, which is based on the density functional theory (DFT). The structures and electronic properties of CH4, C2H6, CO2 and N2 molecules were calculated by the generalized gradient approximation (GGA), for a coverage of 1 monolayer (ML). Under the same conditions, the density of states (DOS) of CaCO3 (100) surfaces before and after the adsorption of shale gas molecules at high-symmetry adsorption sites were compared. The results showed that the adsorption energies of CH4, C2H6, CO2 and N2 on CaCO3 (100) surfaces were between 0.2683 eV and -0.7388 eV. When a CH4 molecule was adsorbed at a hollow site and its 2 hydrogen atoms were parallel to the long diagonal (H3) on the CaCO3 (100) surface, it had the most stable adsorption, and the adsorption energy was only -0.4160 eV. The change of adsorption energy of CH4 was no more than 0.0535 eV. Compared with the DOS distribution of CH4 before adsorption, it shifted to the left overall after adsorption. At the same time, the partial density of states (PDOS) curves of CaCO3 (100) surfaces before and after adsorption basically overlapped. This work showed that the adsorption effect of shale gas on calcium carbonate is very weak, and the adsorption is physisorption at the molecular level.

Systematic variation in the temperature dependence of physiological and ecological traits

PubMed Central

Dell, Anthony I.; Pawar, Samraat; Savage, Van M.

2011-01-01

To understand the effects of temperature on biological systems, we compile, organize, and analyze a database of 1,072 thermal responses for microbes, plants, and animals. The unprecedented diversity of traits (n = 112), species (n = 309), body sizes (15 orders of magnitude), and habitats (all major biomes) in our database allows us to quantify novel features of the temperature response of biological traits. In particular, analysis of the rising component of within-species (intraspecific) responses reveals that 87% are fit well by the Boltzmann–Arrhenius model. The mean activation energy for these rises is 0.66 ± 0.05 eV, similar to the reported across-species (interspecific) value of 0.65 eV. However, systematic variation in the distribution of rise activation energies is evident, including previously unrecognized right skewness around a median of 0.55 eV. This skewness exists across levels of organization, taxa, trophic groups, and habitats, and it is partially explained by prey having increased trait performance at lower temperatures relative to predators, suggesting a thermal version of the life-dinner principle—stronger selection on running for your life than running for your dinner. For unimodal responses, habitat (marine, freshwater, and terrestrial) largely explains the mean temperature at which trait values are optimal but not variation around the mean. The distribution of activation energies for trait falls has a mean of 1.15 ± 0.39 eV (significantly higher than rises) and is also right-skewed. Our results highlight generalities and deviations in the thermal response of biological traits and help to provide a basis to predict better how biological systems, from cells to communities, respond to temperature change. PMID:21606358

Structures of Mo2Oy- and Mo2Oy (y=2, 3, and 4) studied by anion photoelectron spectroscopy and density functional theory calculations.

PubMed

Yoder, Bruce L; Maze, Joshua T; Raghavachari, Krishnan; Jarrold, Caroline Chick

2005-03-01

The competitive structural isomers of the Mo(2)O(y) (-)Mo(2)O(y) (y=2, 3, and 4) clusters are investigated using a combination of anion photoelectron (PE) spectroscopy and density functional theory calculations. The PE spectrum and calculations for MoO(3) (-)MoO(3) are also presented to show the level of agreement to be expected between the spectra and calculations. For MoO(3) (-) and MoO(3), the calculations predict symmetric C(3v) structures, an adiabatic electron affinity of 3.34 eV, which is above the observed value 3.17(2) eV. However, there is good agreement between observed and calculated vibrational frequencies and band profiles. The PE spectra of Mo(2)O(2) (-) and Mo(2)O(3) (-) are broad and congested, with partially resolved vibrational structure on the lowest energy bands observed in the spectra. The electron affinities (EA(a)s) of the corresponding clusters are 2.24(2) and 2.33(7) eV, respectively. Based on the calculations, the most stable structure of Mo(2)O(2) (-) is Y shaped, with the two Mo atoms directly bonded. Assignment of the Mo(2)O(3) (-) spectrum is less definitive, but a O-Mo-O-Mo-O structure is more consistent with overall electronic structure observed in the spectrum. The PE spectrum of Mo(2)O(4) (-) shows cleanly resolved vibrational structure and electronic bands, and the EA of the corresponding Mo(2)O(4) is determined to be 2.13(4) eV. The structure most consistent with the observed spectrum has two oxygen bridge bonds between the Mo atoms.

H2CN+ and H2CNH+: New insight into the structure and dynamics from mass-selected threshold photoelectron spectra

NASA Astrophysics Data System (ADS)

Holzmeier, Fabian; Lang, Melanie; Hader, Kilian; Hemberger, Patrick; Fischer, Ingo

2013-06-01

In this paper, we reinvestigate the photoionization of nitrogen containing reactive intermediates of the composition H2CN and H2CNH, molecules of importance in astrochemistry and biofuel combustion. In particular, H2CN is also of considerable interest to theory, because of its complicated potential energy surface. The species were generated by flash pyrolysis, ionized with vacuum ultraviolet synchrotron radiation, and studied by mass-selected threshold photoelectron (TPE) spectroscopy. In the mass-selected TPE-spectrum of m/z = 28, contributions of all four isomers of H2CN were identified. The excitation energy to the triplet cation of the methylene amidogen radical H2CN was determined to be 12.32 eV. Considerable activity in the C-N mode of the cation is visible. Furthermore, we derived values for excitation into the triplet cations of 11.72 eV for cis-HCNH, 12.65 eV for trans-HCNH, and 11.21 eV for H2NC. The latter values are probably accurate to within one vibrational quantum. The spectrum features an additional peak at 10.43 eV that corresponds to excitation into the C2v-symmetric H2CN+. As this structure constitutes a saddle point, the peak is assigned to an activated complex on the singlet potential energy surface of the cation, corresponding to a hydrogen atom migration. For methanimine, H2CNH, the adiabatic ionization energy IEad was determined to be 9.99 eV and the vibrational structure of the spectrum was analyzed in detail. The uncertainty of earlier values that simply assigned the signal onset to the IEad is thus considerably reduced. The spectrum is dominated by the H-N-C bending mode ν1+ and the rocking mode ν3+. All experimental data were supported by calculations and Franck-Condon simulations.

Formation of positive cluster ions Li(n) Br (n = 2-7) and ionization energies studied by thermal ionization mass spectrometry.

PubMed

Veličković, S R; Đustebek, J B; Veljković, F M; Veljković, M V

2012-05-01

Clusters of the type Li(n)X (X = halides) can be considered as potential building blocks of cluster-assembly materials. In this work, Li(n)Br (n = 2-7) clusters were obtained by a thermal ionization source of modified design and selected by a magnetic sector mass spectrometer. Positive ions of the Li(n)Br (n = 4-7) cluster were detected for the first time. The order of ion intensities was Li(2)Br(+) > Li(4)Br(+) > Li(5)Br(+) > Li(6)Br(+) > Li(3)Br(+). The ionization energies (IEs) were measured and found to be 3.95 ± 0.20 eV for Li(2)Br, 3.92 ± 0.20 eV for Li(3)Br, 3.93 ± 0.20 eV for Li(4)Br, 4.08 ± 0.20 eV for Li(5)Br, 4.14 ± 0.20 eV for Li(6)Br and 4.19 ± 0.20 eV for Li(7)Br. All of these clusters have a much lower ionization potential than that of the lithium atom, so they belong to the superalkali class. The IEs of Li(n)Br (n = 2-4) are slightly lower than those in the corresponding small Li(n) or Li(n)H clusters, whereas the IEs of Li(n)Br are very similar to those of Li(n) or Li(n)H for n = 5 and 6. The thermal ionization source of modified design is an important means for simultaneously obtaining and measuring the IEs of Li(n)Br (n = 2-7) clusters (because their ions are hermodynamically stable with respect to the loss of lithium atoms in the gas phase) and increasingly contributes toward the development of clusters for practical applications. Copyright © 2012 John Wiley & Sons, Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacmann, K.; Maneira, M.J.P.; Moutinho, A.M.C.

The reaction K+ACl/sub 4/..-->..K/sup +/+(A-Cl/sub 4/)/sup -/* with A = Sn and C was examined as a function of the collision energy from threshold up to about 40 eV in the c.m. system. Total cross sections of the mass-selected negative ions and doubly differential cross sections (energy and angle) of the K/sup +/ ions have been determined. Electron affinities, bond energies, and electronic excitation were calculated from the appearance potentials. In addition, the total cross sections for SnCl/sub 4/ were measured and are contrasted with the earlier results of CCl/sub 4/ from Dispert and Lacmann. Although both parent molecules havemore » the same electron affinity within their error limits (2.2 eV for SnCl/sub 4/ and 2.0 eV for CCl/sub 4/) and the same dissociation energy for the negative ions of 1.4 +- 0.2 eV, the product ion yields differ drastically. The main negative ion yield in K+SnCl/sub 4/ results from SnCl/sup -//sub 4/ formation (over 80%). Its lowest dissociation channel leads to SnCl/sup -//sub 3/ formation, while Cl/sup -/ ions are the main ions produced (90%) from CCl/sub 4/, with only 7% leading to CCl/sup -//sub 3/+Cl formation at higher energies. These results support orbital energy considerations of electron addition to SnCl/sub 4/ and CCl/sub 4/ as applied to the results of reactive collisions of these molecules. The electron affinity and an electronically excited state of SnCl/sub 3/ have been also determined. Morse potentials of CCl/sup -//sub 4/ and SnCl/sup -//sub 4/ were fitted to the experimental results of energy loss measurements from this work. The vertical electron affinities thus derived are 1.15 eV for SnCl/sub 4/ and -1.0 eV for CCl/sub 4/.« less

Dissociative photoionization mechanism of methanol isotopologues (CH3OH, CD3OH, CH3OD and CD3OD) by iPEPICO: energetics, statistical and non-statistical kinetics and isotope effects.

PubMed

Borkar, Sampada; Sztáray, Bálint; Bodi, Andras

2011-07-28

The dissociative photoionization of energy selected methanol isotopologue (CH(3)OH, CD(3)OH, CH(3)OD and CD(3)OD) cations was investigated using imaging Photoelectron Photoion Coincidence (iPEPICO) spectroscopy. The first dissociation is an H/D-atom loss from the carbon, also confirmed by partial deuteration. Somewhat above 12 eV, a parallel H(2)-loss channel weakly asserts itself. At photon energies above 15 eV, in a consecutive hydrogen molecule loss to the first H-atom loss, the formation of CHO(+)/CDO(+) dominates as opposed to COH(+)/COD(+) formation. We see little evidence for H-atom scrambling in these processes. In the photon energy range corresponding to the B[combining tilde] and C[combining tilde] ion states, a hydroxyl radical loss appears yielding CH(3)(+)/CD(3)(+). Based on the branching ratios, statistical considerations and ab initio calculations, this process is confirmed to take place on the first electronically excited Ã(2)A' ion state. Uncharacteristically, internal conversion is outcompeted by unimolecular dissociation due to the apparently weak Renner-Teller-like coupling between the X[combining tilde] and the à ion states. The experimental 0 K appearance energies of the ions CH(2)OH(+), CD(2)OH(+), CH(2)OD(+) and CD(2)OD(+) are measured to be 11.646 ± 0.003 eV, 11.739 ± 0.003 eV, 11.642 ± 0.003 eV and 11.737 ± 0.003 eV, respectively. The E(0)(CH(2)OH(+)) = 11.6454 ± 0.0017 eV was obtained based on the independently measured isotopologue results and calculated zero point effects. The 0 K heat of formation of CH(2)OH(+), protonated formaldehyde, was determined to be 717.7 ± 0.7 kJ mol(-1). This yields a 0 K heat of formation of CH(2)OH of -11.1 ± 0.9 kJ mol(-1) and an experimental 298 K proton affinity of formaldehyde of 711.6 ± 0.8 kJ mol(-1). The reverse barrier to homonuclear H(2)-loss from CH(3)OH(+) is determined to be 36 kJ mol(-1), whereas for heteronuclear H(2)-loss from CH(2)OH(+) it is found to be 210 kJ mol(-1). This journal is © the Owner Societies 2011

A theoretical study of the adiabatic and vertical ionization potentials of water.

PubMed

Feller, David; Davidson, Ernest R

2018-06-21

Theoretical predictions of the three lowest adiabatic and vertical ionization potentials of water were obtained from the Feller-Peterson-Dixon approach. This approach combines multiple levels of coupled cluster theory with basis sets as large as aug-cc-pV8Z in some cases and various corrections up to and including full configuration interaction theory. While agreement with experiment for the adiabatic ionization potential of the lowest energy 2 B 1 state was excellent, differences for other states were much larger, sometimes exceeding 10 kcal/mol (0.43 eV). Errors of this magnitude are inconsistent with previous benchmark work on 52 adiabatic ionization potentials, where a root mean square of 0.20 kcal/mol (0.009 eV) was found. Difficulties in direct comparisons between theory and experiment for vertical ionization potentials are discussed. With regard to the differences found for the 2 A 1 / 2 Π u and 2 B 2 adiabatic ionization potentials, a reinterpretation of the experimental spectrum appears justified.

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice.

PubMed

Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Rajderkar, Sudha; Ray, Manas K; Mochida, Yoshiyuki; Allen, Benjamin; Lefebvre, Veronique; Hung, Irene H; Ornitz, David M; Kunieda, Tetsuo; Mishina, Yuji

2016-12-01

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome.

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice

PubMed Central

Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Ray, Manas K.; Mochida, Yoshiyuki; Lefebvre, Veronique; Hung, Irene H.; Kunieda, Tetsuo; Mishina, Yuji

2016-01-01

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome. PMID:28027321

Comparison of two equation-of-state models for partially ionized aluminum: Zel'dovich and Raizer's model versus the activity expansion code

NASA Astrophysics Data System (ADS)

Harrach, Robert J.; Rogers, Forest J.

1981-09-01

Two equation-of-state (EOS) models for multipy ionized matter are evaluated for the case of an aluminum plasma in the temperature range from about one eV to several hundred eV, spanning conditions of weak to strong ionization. Specifically, the simple analytical mode of Zel'dovich and Raizer and the more comprehensive model comprised by Rogers' plasma physics avtivity expansion code (ACTEX) are used to calculate the specific internal energy ɛ and average degree of ionization Z¯*, as functons of temperature T and density ρ. In the absence of experimental data, these results are compared against each other, covering almost five orders-of-magnitude variation in ɛ and the full range of Z¯* We find generally good agreement between the two sets of results, especially for low densities and for temperatures near the upper end of the rage. Calculated values of ɛ(T) agree to within ±30% over nearly the full range in T for densities below about 1 g/cm3. Similarly, the two models predict values of Z¯*(T) which track each other fairly well; above 20 eV the discrepancy is less than ±20% fpr ρ≲1 g/cm3. Where the calculations disagree, we expect the ACTEX code to be more accurate than Zel'dovich and Raizer's model, by virtue of its more detailed physics content.

Kinetic barriers for Cd and Te adatoms on Cd and Te terminated CdTe (111) surface using ab initio simulations

NASA Astrophysics Data System (ADS)

Naderi, Ebadollah; Nanavati, Sachin P.; Majumder, Chiranjib; Ghaisas, S. V.

2014-03-01

In the present work we have calculated using density functional theory (DFT), diffusion barrier potentials on both the CdTe (111) surfaces, Cd terminated (A-type) & Te terminated (B-type). We employ nudge elastic band method (NEB) for obtaining the barrier potentials. The barrier is computed for Cd and for Te adatoms on both A-type and B-type surfaces. We report two energetically favourable positions along the normal to the surface, one above and other below the surface. The one above the surface has binding energy slightly more the one below. According to the results of this work, binding energy (in all cases) for adatoms are reasonable and close to experimental data. The barrier potential for hopping adatoms (Cd and Te) on both the surfaces is less than 0.35 eV. Apart from these most probable sites, there are other at least two sites on both the types of surfaces which are meta stable. We have also computed barriers for hopping to and from these meta stable positions. The present results can shade light on the defect formation mechanism in CdTe thin films during growth. The authors would like to thank C-DAC for the computing time on its PARAM series of supercomputers and DST Govt. of India, for partial funding.

Signed, Sealed, Delivered: Microenvironmental Modulation of Extracellular Vesicle-Dependent Immunoregulation in the Lung.

PubMed

Schneider, Daniel J; Speth, Jennifer M; Peters-Golden, Marc

2016-01-01

Unconventional secretion and subsequent uptake of molecular cargo via extracellular vesicles (EVs) is an important mechanism by which cells can exert paracrine effects. While this phenomenon has been widely characterized in the context of their ability to promote inflammation, less is known about the ability of EVs to transfer immunosuppressive cargo. Maintenance of normal physiology in the lung requires suppression of potentially damaging inflammatory responses to the myriad of insults to which it is continually exposed. Recently, our laboratory has reported the ability of alveolar macrophages (AMs) to secrete suppressors of cytokine signaling (SOCS) proteins within microvesicles (MVs) and exosomes (Exos). Uptake of these EVs by alveolar epithelial cells (AECs) resulted in inhibition of pro-inflammatory STAT activation in response to cytokines. Moreover, AM packaging of SOCS within EVs could be rapidly tuned in response to exogenous or AEC-derived substances. In this article we will highlight gaps in knowledge regarding microenvironmental modulation of cargo packaging and utilization as well as EV secretion and uptake. Advances in these areas are critical for improving understanding of intercellular communication in the immune system and for therapeutic application of artificial vesicles aimed at treatment of diseases characterized by dysregulated inflammation.

Signed, Sealed, Delivered: Microenvironmental Modulation of Extracellular Vesicle-Dependent Immunoregulation in the Lung

PubMed Central

Schneider, Daniel J.; Speth, Jennifer M.; Peters-Golden, Marc

2016-01-01

Unconventional secretion and subsequent uptake of molecular cargo via extracellular vesicles (EVs) is an important mechanism by which cells can exert paracrine effects. While this phenomenon has been widely characterized in the context of their ability to promote inflammation, less is known about the ability of EVs to transfer immunosuppressive cargo. Maintenance of normal physiology in the lung requires suppression of potentially damaging inflammatory responses to the myriad of insults to which it is continually exposed. Recently, our laboratory has reported the ability of alveolar macrophages (AMs) to secrete suppressors of cytokine signaling (SOCS) proteins within microvesicles (MVs) and exosomes (Exos). Uptake of these EVs by alveolar epithelial cells (AECs) resulted in inhibition of pro-inflammatory STAT activation in response to cytokines. Moreover, AM packaging of SOCS within EVs could be rapidly tuned in response to exogenous or AEC-derived substances. In this article we will highlight gaps in knowledge regarding microenvironmental modulation of cargo packaging and utilization as well as EV secretion and uptake. Advances in these areas are critical for improving understanding of intercellular communication in the immune system and for therapeutic application of artificial vesicles aimed at treatment of diseases characterized by dysregulated inflammation. PMID:27626032

Field Evaluation of Medium-Duty Plug-in Electric Delivery Trucks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prohaska, Robert; Simpson, Mike; Ragatz, Adam

2016-12-01

This report focuses on medium-duty electric delivery vehicles operated by Frito-Lay North America (FLNA) at its Federal Way, Washington, distribution center. The 100% electric drive system is an alternative to conventional diesel delivery trucks and reduces both energy consumption and carbon dioxide (CO2) emissions. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific electric vehicle (EV) technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles,more » as well as a 46.4% reduction in CO 2 equivalent emissions based on the local energy generation source. In addition to characterizing the in-use performance of the EVs compared to the conventional diesels, detailed facility load data were collected at the main building power feed as well as from each of the 10 EV chargers to better understand the broader implications associated with commercial EV deployment. These facility loads were incorporated into several modeling scenarios to demonstrate the potential benefits of integrating onsite renewables.« less

Pathway to 50% efficient inverted metamorphic concentrator solar cells

NASA Astrophysics Data System (ADS)

Geisz, John F.; Steiner, Myles A.; Jain, Nikhil; Schulte, Kevin L.; France, Ryan M.; McMahon, William E.; Perl, Emmett E.; Horowitz, Kelsey A. W.; Friedman, Daniel J.

2017-09-01

Series-connected five (5J) and six junction (6J) concentrator solar cell strategies have the realistic potential to exceed 50% efficiency to enable low-cost CPV systems. We propose three strategies for developing a practical 6J device. We have overcome many of the challenges required to build such concentrator solar cell devices: We have developed 2.1 eV AlGaInP, 1.7 eV AlGaAs, and 1.7 eV GaInAsP junctions with external radiative efficiency greater than 0.1%. We have developed a transparent tunnel junction that absorbs minimal light intended for the second junction yet resists degradation under thermal load. We have developed metamorphic grades from the GaAs to the InP lattice constant that are transparent to sub-GaAs bandgap light. We have grown and compared low bandgap junctions (0.7eV - 1.2 eV) using metamorphic GaInAs, metamorphic GaInAsP, and GaInAsP lattice-matched to InP. And finally, we have demonstrated excellent performance in a high voltage, low current 4 junction inverted metamorphic device using 2.1, 1.7, 1.4, and 1.1 eV junctions with over 8.7 mA/cm2 one-sun current density that operates up to 1000 suns without tunnel junction failure.

Pathway to 50% Efficient Inverted Metamorphic Concentrator Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geisz, John F; Steiner, Myles A; Jain, Nikhil

Series-connected five (5J) and six junction (6J) concentrator solar cell strategies have the realistic potential to exceed 50% efficiency to enable low-cost CPV systems. We propose three strategies for developing a practical 6J device. We have overcome many of the challenges required to build such concentrator solar cell devices: We have developed 2.1 eV AlGaInP, 1.7 eV AlGaAs, and 1.7 eV GaInAsP junctions with external radiative efficiency greater than 0.1%. We have developed a transparent tunnel junction that absorbs minimal light intended for the second junction yet resists degradation under thermal load. We have developed metamorphic grades from the GaAsmore » to the InP lattice constant that are transparent to sub-GaAs bandgap light. We have grown and compared low bandgap junctions (0.7eV - 1.2 eV) using metamorphic GaInAs, metamorphic GaInAsP, and GaInAsP lattice-matched to InP. And finally, we have demonstrated excellent performance in a high voltage, low current 4 junction inverted metamorphic device using 2.1, 1.7, 1.4, and 1.1 eV junctions with over 8.7 mA/cm2 one-sun current density that operates up to 1000 suns without tunnel junction failure.« less

Properties of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions through photoelectron spectroscopy and density functional theory calculations.

PubMed

Yin, Shi; Bernstein, Elliot R

2016-10-21

A new magnetic-bottle time-of-flight photoelectron spectroscopy (PES) apparatus is constructed in our laboratory. The PES spectra of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide [FeS m (SH) n - ; m, n = 0-3, 0 < (m + n) ≤ 3] cluster anions, obtained at 2.331 eV (532 nm) and 3.492 eV (355 nm) photon energies, are reported. The electronic structure and bonding properties of these clusters are additionally investigated at different levels of density functional theory. The most probable structures and ground state spin multiplicity for these cluster anions are tentatively assigned by comparing their theoretical first vertical detachment energies (VDEs) with their respective experiment values. The behavior of S and (SH) as ligands in these iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions is investigated and compared. The experimental first VDEs for Fe(SH) 1-3 - cluster anions are lower than those found for their respective FeS 1-3 - cluster anions. The experimental first VDEs for FeS 1-3 - clusters are observed to increase for the first two S atoms bound to Fe - ; however, due to the formation of an S-S bond for the FeS 3 - cluster, its first VDE is found to be ∼0.41 eV lower than the first VDE for the FeS 2 - cluster. The first VDEs of Fe(SH) 1-3 - cluster anions are observed to increase with the increasing numbers of SH groups. The calculated partial charges of the Fe atom for ground state FeS 1-3 - and Fe(SH) 1-3 - clusters are apparently related to and correlated with their determined first VDEs. The higher first VDE is correlated with a higher, more positive partial charge for the Fe atom of these cluster anions. Iron sulfide/hydrosulfide mixed cluster anions are also explored in this work: the first VDE for FeS(SH) - is lower than that for FeS 2 - , but higher than that for Fe(SH) 2 - ; the first VDEs for FeS 2 (SH) - and FeS(SH) 2 - are close to that for FeS 3 - , but higher than that for Fe(SH) 3 - . The first VDEs of general iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide clusters [FeS m (SH) n - ; m, n = 0-3, 0 < (m + n) ≤ 3] are dependent on three properties of these anions: 1. the partial charge on the Fe atom, 2. disulfide bond formation (S-S) in the cluster, and 3. the number of hydrosulfide ligands in the cluster. The higher the partial charge on the Fe atom of these clusters, the larger the first VDE; however, cluster S-S bonding and more (SH) ligands in the cluster lower the cluster anion first VDE.

Properties of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions through photoelectron spectroscopy and density functional theory calculations

NASA Astrophysics Data System (ADS)

Yin, Shi; Bernstein, Elliot R.

2016-10-01

A new magnetic-bottle time-of-flight photoelectron spectroscopy (PES) apparatus is constructed in our laboratory. The PES spectra of iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide [FeSm(SH)n-; m, n = 0-3, 0 < (m + n) ≤ 3] cluster anions, obtained at 2.331 eV (532 nm) and 3.492 eV (355 nm) photon energies, are reported. The electronic structure and bonding properties of these clusters are additionally investigated at different levels of density functional theory. The most probable structures and ground state spin multiplicity for these cluster anions are tentatively assigned by comparing their theoretical first vertical detachment energies (VDEs) with their respective experiment values. The behavior of S and (SH) as ligands in these iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide cluster anions is investigated and compared. The experimental first VDEs for Fe(SH)1-3- cluster anions are lower than those found for their respective FeS1-3- cluster anions. The experimental first VDEs for FeS1-3- clusters are observed to increase for the first two S atoms bound to Fe-; however, due to the formation of an S-S bond for the FeS3- cluster, its first VDE is found to be ˜0.41 eV lower than the first VDE for the FeS2- cluster. The first VDEs of Fe(SH)1-3- cluster anions are observed to increase with the increasing numbers of SH groups. The calculated partial charges of the Fe atom for ground state FeS1-3- and Fe(SH)1-3- clusters are apparently related to and correlated with their determined first VDEs. The higher first VDE is correlated with a higher, more positive partial charge for the Fe atom of these cluster anions. Iron sulfide/hydrosulfide mixed cluster anions are also explored in this work: the first VDE for FeS(SH)- is lower than that for FeS2-, but higher than that for Fe(SH)2-; the first VDEs for FeS2(SH)- and FeS(SH)2- are close to that for FeS3-, but higher than that for Fe(SH)3-. The first VDEs of general iron sulfide, hydrosulfide, and mixed sulfide/hydrosulfide clusters [FeSm(SH)n-; m, n = 0-3, 0 < (m + n) ≤ 3] are dependent on three properties of these anions: 1. the partial charge on the Fe atom, 2. disulfide bond formation (S-S) in the cluster, and 3. the number of hydrosulfide ligands in the cluster. The higher the partial charge on the Fe atom of these clusters, the larger the first VDE; however, cluster S-S bonding and more (SH) ligands in the cluster lower the cluster anion first VDE.

Analysis of multiple scattering contributions in electron-impact ionization of molecular hydrogen

NASA Astrophysics Data System (ADS)

Ren, Xueguang; Hossen, Khokon; Wang, Enliang; Pindzola, M. S.; Dorn, Alexander; Colgan, James

2017-10-01

We report a combined experimental and theoretical study on the low-energy (E 0 = 31.5 eV) electron-impact ionization of molecular hydrogen (H2). Triple differential cross sections are measured for a range of fixed emission angles of one outgoing electron between {θ }1=-70^\\circ and -130° covering the full 4π solid angle of the second electron. The energy sharing of the outgoing electrons varies from symmetric ({E}1={E}2=8 eV) to highly asymmetric (E 1 = 1 eV and E 2 = 15 eV). In addition to the binary and recoil lobes, a structure is observed perpendicular to the incoming beam direction which is due to multiple scattering of the projectile inside the molecular potential. The absolutely normalized experimental cross sections are compared with results from the time-dependent close-coupling (TDCC) calculations. Molecular alignment dependent TDCC results demonstrate that these structures are only present if the molecule axis is lying in the scattering plane.

Summary of the ISEV workshop on extracellular vesicles as disease biomarkers, held in Birmingham, UK, during December 2017

PubMed Central

Carter, David R. F.; Cheng, Lesley; Compton, Carolyn; Daaboul, George; Devitt, Andrew; Falcon-Perez, Juan Manuel; Gardiner, Chris; Helmbrecht, Clemens; Hendrix, An; Hoffman, Andrew; Kalluri, Raghu; Kang, Ji Yoon; Lässer, Cecilia; Lawson, Charlotte; Lenassi, Metka; Levin, Carina; Llorente, Alicia; Martens-Uzunova, Elena S.; Möller, Andreas; Ochiya, Takahiro; Pink, Ryan C; Tahara, Hidetoshi; Wauben, Marca H. M.; Webber, Jason P.; Yin, Hang; Nieuwland, Rienk

2018-01-01

ABSTRACT This report summarises the presentations and activities of the ISEV Workshop on extracellular vesicle biomarkers held in Birmingham, UK during December 2017. Among the key messages was broad agreement about the importance of biospecimen science. Much greater attention needs to be paid towards the provenance of collected samples. The workshop also highlighted clear gaps in our knowledge about pre-analytical factors that alter extracellular vesicles (EVs). The future utility of certified standards for credentialing of instruments and software, to analyse EV and for tracking the influence of isolation steps on the structure and content of EVs were also discussed. Several example studies were presented, demonstrating the potential utility for EVs in disease diagnosis, prognosis, longitudinal serial testing and stratification of patients. The conclusion of the workshop was that more effort focused on pre-analytical issues and benchmarking of isolation methods is needed to strengthen collaborations and advance more effective biomarkers.

First measurement of Lyman alpha x-ray lines in hydrogen-like vanadium: results and implications for precision wavelength metrology and tests of QED

NASA Astrophysics Data System (ADS)

Gillaspy, J. D.; Chantler, C. T.; Paterson, D.; Hudson, L. T.; Serpa, F. G.; Takács, E.

2010-04-01

The first measurement of hydrogen-like vanadium x-ray Lyman alpha transitions has been made. The measurement was made on an absolute scale, fully independent of atomic structure calculations. Sufficient signal was obtained to reduce the statistical uncertainty to a small fraction of the total uncertainty budget. Potential sources of systematic error due to Doppler shifts were eliminated by performing the measurement on trapped ions. The energies for Ly α1 (1s-2p3/2) and Ly α2 (1s-2p1/2) are found to be 5443.95(25) eV and 5431.10(25) eV, respectively. These results are within approximately 1.5 σ (experimental) of the theoretical values 5443.63 eV and 5430.70 eV. The results are discussed in terms of their relation to the Lamb shift and the development of an x-ray wavelength standard based on a compact source of trapped highly charged ions.

Efficient RNA drug delivery using red blood cell extracellular vesicles.

PubMed

Usman, Waqas Muhammad; Pham, Tin Chanh; Kwok, Yuk Yan; Vu, Luyen Tien; Ma, Victor; Peng, Boya; Chan, Yuen San; Wei, Likun; Chin, Siew Mei; Azad, Ajijur; He, Alex Bai-Liang; Leung, Anskar Y H; Yang, Mengsu; Shyh-Chang, Ng; Cho, William C; Shi, Jiahai; Le, Minh T N

2018-06-15

Most of the current methods for programmable RNA drug therapies are unsuitable for the clinic due to low uptake efficiency and high cytotoxicity. Extracellular vesicles (EVs) could solve these problems because they represent a natural mode of intercellular communication. However, current cellular sources for EV production are limited in availability and safety in terms of horizontal gene transfer. One potentially ideal source could be human red blood cells (RBCs). Group O-RBCs can be used as universal donors for large-scale EV production since they are readily available in blood banks and they are devoid of DNA. Here, we describe and validate a new strategy to generate large-scale amounts of RBC-derived EVs for the delivery of RNA drugs, including antisense oligonucleotides, Cas9 mRNA, and guide RNAs. RNA drug delivery with RBCEVs shows highly robust microRNA inhibition and CRISPR-Cas9 genome editing in both human cells and xenograft mouse models, with no observable cytotoxicity.

Analysis of energy consumption and emission of the heterogeneous traffic flow consisting of traditional vehicles and electric vehicles

NASA Astrophysics Data System (ADS)

Xiao, Hong; Huang, Hai-Jun; Tang, Tie-Qiao

2017-12-01

Electric vehicle (EV) has become a potential traffic tool, which has attracted researchers to explore various traffic phenomena caused by EV (e.g. congestion, electricity consumption, etc.). In this paper, we study the energy consumption (including the fuel consumption and the electricity consumption) and emissions of heterogeneous traffic flow (that consists of the traditional vehicle (TV) and EV) under three traffic situations (i.e. uniform flow, shock and rarefaction waves, and a small perturbation) from the perspective of macro traffic flow. The numerical results show that the proportion of electric vehicular flow has great effects on the TV’s fuel consumption and emissions and the EV’s electricity consumption, i.e. the fuel consumption and emissions decrease while the electricity consumption increases with the increase of the proportion of electric vehicular flow. The results can help us better understand the energy consumption and emissions of the heterogeneous traffic flow consisting of TV and EV.

Probing optical band gaps at the nanoscale in NiFe₂O₄ and CoFe₂O₄ epitaxial films by high resolution electron energy loss spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dileep, K.; Loukya, B.; Datta, R., E-mail: ranjan@jncasr.ac.in

2014-09-14

Nanoscale optical band gap variations in epitaxial thin films of two different spinel ferrites, i.e., NiFe₂O₄ (NFO) and CoFe₂O₄ (CFO), have been investigated by spatially resolved high resolution electron energy loss spectroscopy. Experimentally, both NFO and CFO show indirect/direct band gaps around 1.52 eV/2.74 and 2.3 eV, and 1.3 eV/2.31 eV, respectively, for the ideal inverse spinel configuration with considerable standard deviation in the band gap values for CFO due to various levels of deviation from the ideal inverse spinel structure. Direct probing of the regions in both the systems with tetrahedral A site cation vacancy, which is distinct frommore » the ideal inverse spinel configuration, shows significantly smaller band gap values. The experimental results are supported by the density functional theory based modified Becke-Johnson exchange correlation potential calculated band gap values for the different cation configurations.« less

Extracellular vesicles in parasitic diseases

PubMed Central

Marcilla, Antonio; Martin-Jaular, Lorena; Trelis, Maria; de Menezes-Neto, Armando; Osuna, Antonio; Bernal, Dolores; Fernandez-Becerra, Carmen; Almeida, Igor C.; del Portillo, Hernando A.

2014-01-01

Parasitic diseases affect billions of people and are considered a major public health issue. Close to 400 species are estimated to parasitize humans, of which around 90 are responsible for great clinical burden and mortality rates. Unfortunately, they are largely neglected as they are mainly endemic to poor regions. Of relevance to this review, there is accumulating evidence of the release of extracellular vesicles (EVs) in parasitic diseases, acting both in parasite–parasite inter-communication as well as in parasite–host interactions. EVs participate in the dissemination of the pathogen and play a role in the regulation of the host immune systems. Production of EVs from parasites or parasitized cells has been described for a number of parasitic infections. In this review, we provide the most relevant findings of the involvement of EVs in intercellular communication, modulation of immune responses, involvement in pathology, and their potential as new diagnostic tools and therapeutic agents in some of the major human parasitic pathogens. PMID:25536932

Application of EVA guidelines and design criteria. Volume 2: EVA workstation conceptual designs

NASA Technical Reports Server (NTRS)

Brown, N. E.

1973-01-01

Several EV workstation concepts were developed and are documented. The workstation concepts were developed following a comprehensive analysis of potential EV missions, functions, and tasks as interpreted from NASA and contractor space shuttle and space station studies, mission models, and related reports. The design of a versatile, portable EVA workstation is aimed at reducing the design and development costs for each mission and aiding in the development of on-orbit serviceable payloads.

Direct Search for Low Mass Dark Matter Particles with CCDs

DOE PAGES

Barreto, J.; Cease, H.; Diehl, H. T.; ...

2012-05-15

A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (RMS ~7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses (~5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

Ultrafast internal conversion dynamics of highly excited pyrrole studied with VUV/UV pump probe spectroscopy.

PubMed

Horton, Spencer L; Liu, Yusong; Chakraborty, Pratip; Matsika, Spiridoula; Weinacht, Thomas

2017-02-14

We study the relaxation dynamics of pyrrole after excitation with an 8 eV pump pulse to a state just 0.2 eV below the ionization potential using vacuum ultraviolet/ultraviolet pump probe spectroscopy. Our measurements in conjunction with electronic structure calculations indicate that pyrrole undergoes rapid internal conversion to the ground state in less than 300 fs. We find that internal conversion to the ground state dominates over dissociation.

Investigation on the interfacial chemical state and band alignment for the sputtering-deposited CaF2/p-GaN heterojunction by angle-resolved X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Zhang, Kexiong; Liao, Meiyong; Sumiya, Masatomo; Koide, Yasuo; Sang, Liwen

2016-11-01

The interfacial chemical state and the band alignment of the sputtering-deposited CaF2/p-GaN hetero-structure were investigated by angle-resolved X-ray photoelectron spectroscopy. The dependence of Ga 3p core-level positions on the collection angles proves that the downward band bending of p-GaN is reduced from 1.51 to 0.85 eV after the deposition of CaF2, which may be due to the reduction of Mg-Ga-O-related interface states by the oxygen-free deposition of CaF2. The band gap of sputtering-deposited CaF2 is estimated to be about 7.97 eV with a potential gradient of 0.48 eV obtained by the variation of the Ca 2p3/2 position on different collection angles. By taking into account the p-GaN surface band bending and potential gradient in the CaF2 layer, large valence and conduction band offsets of 2.66 ± 0.20 and 1.92 ± 0.20 eV between CaF2 and p-GaN are obtained. These results indicate that CaF2 is a promising gate dielectric layer on the p-GaN for the application of metal-insulator-semiconductor devices.

Stability of an oscillating boundary layer

NASA Technical Reports Server (NTRS)

Levchenko, V. Y.; Solovyev, A. S.

1985-01-01

Levchenko and Solov'ev (1972, 1974) have developed a stability theory for space periodic flows, assuming that the Floquet theory is applicable to partial differential equations. In the present paper, this approach is extended to unsteady periodic flows. A complete unsteady formulation of the stability problem is obtained, and the stability characteristics over an oscillating period are determined from the solution of the problem. Calculations carried out for an oscillating incompressible boundary layer on a plate showed that the boundary layer flow may be regarded as a locally parallel flow.

Spectroscopic investigation, hirshfeld surface analysis and molecular docking studies on anti-viral drug entecavir

NASA Astrophysics Data System (ADS)

Fathima Rizwana, B.; Prasana, Johanan Christian; Abraham, Christina Susan; Muthu, S.

2018-07-01

Entecavir, a new deoxyguanine nucleoside analogue, is a selective inhibitor of the replication of the hepatitis B virus. In the present study, Quantum mechanical approach was carried out on the title compound to study the vibrational spectrum, the stability of the compound, the intermolecular and intramolecular interactions by using Density Functional Theory (DFT) with B3LYP 6-311++G(d,p) basis set. The B3LYP/DFT method was chosen because diverse studies have shown that the results obtained with it are in good agreement with those determined by other costly computational methods. The computational methods were aided by the experimental spectroscopic techniques, namely FTIR and FT Raman spectroscopies. The optimized molecular geometry, vibrational wavenumbers, infrared intensities and Raman scattering activities were calculated. The calculated HOMO and LUMO energies were found to be -6.397 eV and -1.504 eV which indicate the charge transfer within the molecule. The maximum absorption wavelength and the band gap energy of the title compound were obtained from the UV absorption spectrum computed theoretically. Natural Bond Orbital analysis has been carried out to explain the charge transfer (or) delocalization of charge due to the intra molecular interactions. The molecule orbital contributions are studied by using the total (TDOS), partial (PDOS), and overlap population (OPDOS) density of states. Molecular electrostatic potential (MEP), First order hyperpolarizability, Hirshfield surface analysis and Fukui functions calculation were also performed. From the calculations the first order hyperpolarizability was found to be 2.3854 × 10-30 esu. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures have been calculated. Molecular docking studies were made on the title compound to study the hydrogen bond interactions and the minimum binding energy was calculated.

Genetic variations in regions of bovine and bovine-like enteroviral 5'UTR from cattle, Indian bison and goat feces.

PubMed

Kosoltanapiwat, Nathamon; Yindee, Marnoch; Chavez, Irwin Fernandez; Leaungwutiwong, Pornsawan; Adisakwattana, Poom; Singhasivanon, Pratap; Thawornkuno, Charin; Thippornchai, Narin; Rungruengkitkun, Amporn; Soontorn, Juthamas; Pearsiriwuttipong, Sasipan

2016-01-25

Bovine enteroviruses (BEV) are members of the genus Enterovirus in the family Picornaviridae. They are predominantly isolated from cattle feces, but also are detected in feces of other animals, including goats and deer. These viruses are found in apparently healthy animals, as well as in animals with clinical signs and several studies reported recently suggest a potential role of BEV in causing disease in animals. In this study, we surveyed the presence of BEV in domestic and wild animals in Thailand, and assessed their genetic variability. Viral RNA was extracted from fecal samples of cattle, domestic goats, Indian bison (gaurs), and deer. The 5' untranslated region (5'UTR) was amplified by nested reverse transcription-polymerase chain reaction (RT-PCR) with primers specific to BEV 5'UTR. PCR products were sequenced and analyzed phylogenetically using the neighbor-joining algorithm to observe genetic variations in regions of the bovine and bovine-like enteroviral 5'UTR found in this study. BEV and BEV-like sequences were detected in the fecal samples of cattle (40/60, 67 %), gaurs (3/30, 10 %), and goats (11/46, 24 %). Phylogenetic analyses of the partial 5'UTR sequences indicated that different BEV variants (both EV-E and EV-F species) co-circulated in the domestic cattle, whereas the sequences from gaurs and goats clustered according to the animal species, suggesting that these viruses are host species-specific. Varieties of BEV and BEV-like 5'UTR sequences were detected in fecal samples from both domestic and wild animals. To our knowledge, this is the first report of the genetic variability of BEV in Thailand.

Adsorption and dissociation of molecular hydrogen on the (0001) surface of double hexagonal close packed americium

NASA Astrophysics Data System (ADS)

Dholabhai, P. P.; Ray, A. K.

2009-01-01

Hydrogen molecule adsorption on the (0001) surface of double hexagonal packed americium has been studied in detail within the framework of density functional theory using a full-potential all-electron linearized augmented plane wave plus local orbitals method (FP-L/APW+lo). Weak molecular hydrogen adsorptions were observed. Adsorption energies were optimized with respect to the distance of the adsorbates from the surface for three approach positions at three adsorption sites, namely t1 (one-fold top), b2 (two-fold bridge), and h3 (three-fold hollow) sites. Adsorption energies were computed at the scalar-relativistic level (no spin-orbit coupling NSOC) and at the fully relativistic level (with spin-orbit coupling SOC). The most stable configuration corresponds to a horizontal adsorption with the molecular approach being perpendicular to a lattice vector. The surface coverage is equivalent to one-fourth of a monolayer (ML), with the adsorption energies at the NSOC and SOC theoretical levels being 0.0997 eV and 0.1022 eV, respectively. The respective distance of the hydrogen molecule from the surface and hydrogen-hydrogen distance was found to be 2.645 Å and 0.789 Å, respectively. The work functions decreased and the net magnetic moments remained almost unchanged in all cases compared with the corresponding quantities of bare dhcp Am (0001) surface. The adsorbate-substrate interactions have been analyzed in detail using the partial charges inside the muffin-tin spheres, difference charge density distributions, and the local density of states. The effects of adsorption on the Am 5f electron localization-delocalization characteristics have been discussed. Reaction barrier for the dissociation of hydrogen molecule has been presented.

The adiabatic energy change of plasma electrons and the frame dependence of the cross-shock potential at collisionless magnetosonic shock waves

NASA Technical Reports Server (NTRS)

Goodrich, C. C.; Scudder, J. D.

1984-01-01

The adiabatic energy gain of electrons in the stationary electric and magnetic field structure of collisionless shock waves was examined analytically in reference to conditions of the earth's bow shock. The study was performed to characterize the behavior of electrons interacting with the cross-shock potential. A normal incidence frame (NIF) was adopted in order to calculate the reversible energy change across a time stationary shock, and comparisons were made with predictions made by the de Hoffman-Teller (HT) model (1950). The electron energy gain, about 20-50 eV, is demonstrated to be consistent with a 200-500 eV potential jump in the bow shock quasi-perpendicular geometry. The electrons lose energy working against the solar wind motional electric field. The reversible energy process is close to that modeled by HT, which predicts that the motional electric field vanishes and the electron energy gain from the electric potential is equated to the ion energy loss to the potential.

Effect of annealing on structural changes and oxygen diffusion in amorphous HfO2 using classical molecular dynamics

NASA Astrophysics Data System (ADS)

Shen, Wenqing; Kumari, Niru; Gibson, Gary; Jeon, Yoocharn; Henze, Dick; Silverthorn, Sarah; Bash, Cullen; Kumar, Satish

2018-02-01

Non-volatile memory is a promising alternative to present memory technologies. Oxygen vacancy diffusion has been widely accepted as one of the reasons for the resistive switching mechanism of transition-metal-oxide based resistive random access memory. In this study, molecular dynamics simulation is applied to investigate the diffusion coefficient and activation energy of oxygen in amorphous hafnia. Two sets of empirical potential, Charge-Optimized Many-Body (COMB) and Morse-BKS (MBKS), were considered to investigate the structural and diffusion properties at different temperatures. COMB predicts the activation energy of 0.53 eV for the temperature range of 1000-2000 K, while MBKS predicts 2.2 eV at high temperature (1600-2000 K) and 0.36 eV at low temperature (1000-1600 K). Structural changes and appearance of nano-crystalline phases with increasing temperature might affect the activation energy of oxygen diffusion predicted by MBKS, which is evident from the change in coordination number distribution and radial distribution function. None of the potentials make predictions that are fully consistent with density functional theory simulations of both the structure and diffusion properties of HfO2. This suggests the necessity of developing a better multi-body potential that considers charge exchange.

Molecular Evolution and Intraclade Recombination of Enterovirus D68 during the 2014 Outbreak in the United States

PubMed Central

Tan, Yi; Hassan, Ferdaus; Schuster, Jennifer E.; Simenauer, Ari; Selvarangan, Rangaraj; Halpin, Rebecca A.; Lin, Xudong; Fedorova, Nadia; Stockwell, Timothy B.; Lam, Tommy Tsan-Yuk; Chappell, James D.; Hartert, Tina V.; Holmes, Edward C.

2015-01-01

ABSTRACT In August 2014, an outbreak of enterovirus D68 (EV-D68) occurred in North America, causing severe respiratory disease in children. Due to a lack of complete genome sequence data, there is only a limited understanding of the molecular evolution and epidemiology of EV-D68 during this outbreak, and it is uncertain whether the differing clinical manifestations of EV-D68 infection are associated with specific viral lineages. We developed a high-throughput complete genome sequencing pipeline for EV-D68 that produced a total of 59 complete genomes from respiratory samples with a 95% success rate, including 57 genomes from Kansas City, MO, collected during the 2014 outbreak. With these data in hand, we performed phylogenetic analyses of complete genome and VP1 capsid protein sequences. Notably, we observed considerable genetic diversity among EV-D68 isolates in Kansas City, manifest as phylogenetically distinct lineages, indicative of multiple introductions of this virus into the city. In addition, we identified an intersubclade recombination event within EV-D68, the first recombinant in this virus reported to date. Finally, we found no significant association between EV-D68 genetic variation, either lineages or individual mutations, and a variety of demographic and clinical variables, suggesting that host factors likely play a major role in determining disease severity. Overall, our study revealed the complex pattern of viral evolution within a single geographic locality during a single outbreak, which has implications for the design of effective intervention and prevention strategies. IMPORTANCE Until recently, EV-D68 was considered to be an uncommon human pathogen, associated with mild respiratory illness. However, in 2014 EV-D68 was responsible for more than 1,000 disease cases in North America, including severe respiratory illness in children and acute flaccid myelitis, raising concerns about its potential impact on public health. Despite the emergence of EV-D68, a lack of full-length genome sequences means that little is known about the molecular evolution of this virus within a single geographic locality during a single outbreak. Here, we doubled the number of publicly available complete genome sequences of EV-D68 by performing high-throughput next-generation sequencing, characterized the evolutionary history of this outbreak in detail, identified a recombination event, and investigated whether there was any correlation between the demographic and clinical characteristics of the patients and the viral variant that infected them. Overall, these results will help inform the design of intervention strategies for EV-D68. PMID:26656685

Ab-initio calculations of structural, electronic, and optical properties of Zn3(VO4)2

NASA Astrophysics Data System (ADS)

Ahmed, Nisar; Mukhtar, S.; Gao, Wei; Zafar Ilyas, Syed

2018-03-01

The structural, electronic, and optical properties of Zn3(VO4)2 are investigated using full potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT). Various approaches are adopted to treat the exchange and correlation potential energy such as generalized gradient approximation (GGA), GGA+U, and the Tran–Blaha modified Becke–Johnson (TB-mBJ) potential. The calculated band gap of 3.424 eV by TB-mBJ is found to be close to the experimental result (3.3 eV). The optical anisotropy is analyzed through optical constants, such as dielectric function and absorption coefficient along parallel and perpendicular crystal orientations. The absorption coefficient reveals high absorption (1.5× {10}6 {cm}}-1) of photons in the ultraviolet region.

Postmidnight depletion of the high-energy tail of the quiet plasmasphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarno-Smith, Lois K.; Liemohn, Michael W.; Katus, Roxanne M.

The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures the high energy tail of the thermal plasmasphere allowing study of topside ionosphere and inner magnetosphere coupling. We statistically analyze a 22 month period of HOPE data, looking at quiet times with a Kp index of less than 3. We investigate the high energy range of the plasmasphere, which consists of ions at energies between 1-10 eV and contains approximately 5% of total plasmaspheric density. Both the fluxes and partial plasma densities over this energy range show H + is depleted the most in the post-midnight sector (1-4 MLT),more » followed by O + and then He +. The relative depletion of each species across the post-midnight sector is not ordered by mass, which reveals ionospheric influence. We compare our results with keV energy electron data from HOPE and the Van Allen Probes Electric Fields and Waves (EFW) instrument spacecraft potential to rule out spacecraft charging. Our conclusion is that the post-midnight ion disappearance is due to diurnal ionospheric temperature variation and charge exchange processes« less

Postmidnight depletion of the high-energy tail of the quiet plasmasphere

DOE PAGES

Sarno-Smith, Lois K.; Liemohn, Michael W.; Katus, Roxanne M.; ...

2015-03-06

The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures the high energy tail of the thermal plasmasphere allowing study of topside ionosphere and inner magnetosphere coupling. We statistically analyze a 22 month period of HOPE data, looking at quiet times with a Kp index of less than 3. We investigate the high energy range of the plasmasphere, which consists of ions at energies between 1-10 eV and contains approximately 5% of total plasmaspheric density. Both the fluxes and partial plasma densities over this energy range show H + is depleted the most in the post-midnight sector (1-4 MLT),more » followed by O + and then He +. The relative depletion of each species across the post-midnight sector is not ordered by mass, which reveals ionospheric influence. We compare our results with keV energy electron data from HOPE and the Van Allen Probes Electric Fields and Waves (EFW) instrument spacecraft potential to rule out spacecraft charging. Our conclusion is that the post-midnight ion disappearance is due to diurnal ionospheric temperature variation and charge exchange processes« less

Homogeneous Emission Line Broadening in the Organo Lead Halide Perovskite CH3NH3PbI3-xClx.

PubMed

Wehrenfennig, Christian; Liu, Mingzhen; Snaith, Henry J; Johnston, Michael B; Herz, Laura M

2014-04-17

The organic-inorganic hybrid perovskites methylammonium lead iodide (CH3NH3PbI3) and the partially chlorine-substituted mixed halide CH3NH3PbI3-xClx emit strong and broad photoluminescence (PL) around their band gap energy of ∼1.6 eV. However, the nature of the radiative decay channels behind the observed emission and, in particular, the spectral broadening mechanisms are still unclear. Here we investigate these processes for high-quality vapor-deposited films of CH3NH3PbI3-xClx using time- and excitation-energy dependent photoluminescence spectroscopy. We show that the PL spectrum is homogenously broadened with a line width of 103 meV most likely as a consequence of phonon coupling effects. Further analysis reveals that defects or trap states play a minor role in radiative decay channels. In terms of possible lasing applications, the emission spectrum of the perovskite is sufficiently broad to have potential for amplification of light pulses below 100 fs pulse duration.

First principles calculation of elastic and magnetic properties of Cr-based full-Heusler alloys

NASA Astrophysics Data System (ADS)

Aly, Samy H.; Shabara, Reham M.

2014-06-01

We present an ab-initio study of the elastic and magnetic properties of Cr-based full-Heusler alloys within the first-principles density functional theory. The lattice constant, magnetic moment, bulk modulus and density of states are calculated using the full-potential nonorthogonal local-orbital minimum basis (FPLO) code in the Generalized Gradient Approximation (GGA) scheme. Only the two alloys Co2CrSi and Fe2CrSi are half-metallic with energy gaps of 0.88 and 0.55 eV in the spin-down channel respectively. We have predicted the metallicity state for Fe2CrSb, Ni2CrIn, Cu2CrIn, and Cu2CrSi alloys. Fe2CrSb shows a strong pressure dependent, e.g. exhibits metallicity at zero pressure and turns into a half-metal at P≥10 GPa. The total and partial magnetic moments of these alloys were studied under higher pressure, e.g. in Co2CrIn, the total magnetic moment is almost unchanged under higher pressure up to 500 GPa.

[Genetic evidence for recombination and mutation in the emergence of human enterovirus 71].

PubMed

Liu, Ai-Ping; Tan, Hui; Xie, Qun; Chen, Bai-Tang; Liu, Xiao-Feng; Zhang, Yong

2014-09-01

We wished to understand the genetic recombination and phylogenetic characteristics of human en- terovirus A71 (EV-A71) and to explore its potential virulence-related sites. Full-length genomes of three EV-A71 strains isolated from patients in Chenzhou City (China) were sequenced and analyzed. Possible re- combination events and crossover sites were analyzed with Recombination Detection Program v4. 1. 6 by comparison with the complete genome sequences of 231 strains of EV-A71. Similarly, plot and bootscanning analyses were undertaken with SimPlot v3. 5. 1. Phylogenetic trees based on the sequences of VP1 regions were constructed with MEGA v5. 2 using the Kimura two-parameter model and neighbor-joining method. Results suggested that recombination events were detected among the three EV-A71 isolates from Chenzhou City. The common main parent sequence was from JF799986 isolated from samples in Guang- zhou City (China) in 2009, and the minor parent sequence was TW/70516/08. Intertypic recombination e- vents were found in the C4b strain (strain SHZH98 isolated in 1998) and C4a strain (Fuyang strain isola- ted in 2008) with the prototype strains of CVA4 and CVA14 in the 3D region. The chi-square test was used to screen-out potential virulence-related sites with nucleotide substitutions of different types of hand, foot, and mouth disease (HFMD) cases using SPSS v19.0. Results suggested that there were no significant nucleotide substitutions between death cases and severe-HFMD cases. Eighteen significant nucleotide substitutions were found between death/severe-HFMD cases and mild-HFMD cases, and all these 18 substitutions were distributed only in P2 and P3 regions. Intertypic recombination among the predominant circulating EV-A71 strains in the Chinese mainland and other EV-A strains probably dates before 1998, and intratypic recombination might have occurred frequently in the HFMD outbreak from 2008 to 2012. Substitutions in the non-capsid region may be correlated with the changes in virulence of EV-A71. These data suggest that researchers should pay more attention to the relationships between substitutions in the noncapsid region and the virulence of the virus.

Characterization of the non-polio enterovirus infections associated with acute flaccid paralysis in South-Western India.

PubMed

Laxmivandana, Rongala; Yergolkar, Prasanna; Gopalkrishna, Varanasi; Chitambar, Shobha D

2013-01-01

Non-polio enteroviruses (NPEVs) have been reported frequently in association with acute flaccid paralysis (AFP) cases during Polio Surveillance Programs (PSPs) worldwide. However, there is limited understanding on the attributes of their infections. This study reports characteristics of NPEVs isolated from AFP cases, investigated during PSPs held in 2009-2010, in Karnataka and Kerala states of south-western India having varied climatic conditions. NPEV cell culture isolates derived from stool specimens that were collected from 422 of 2186 AFP cases (<1-14 years age) and 17 of 41 asymptomatic contacts; and details of all AFP cases/contacts were obtained from National Polio Laboratory, Bangalore. The distribution of NPEV infections among AFP cases and circulation pattern of NPEV strains were determined by statistical analysis of the data. Genotyping of all NPEV isolates was carried out by partial VP1 gene sequencing and phylogenetic analysis. NPEV positive AFP cases were significantly higher in children aged <2 years; with residual paralysis; in summer months; and in regions with relatively hot climate. Genotyping of NPEVs identified predominance of human enteroviruses (HEV)-B species [81.9%-Echoviruses (E): 57.3%; coxsackieviruses (CV) B: 15%; numbered EVs: 8.9%; CVA9: 0.7%] and low levels of HEV-A [14.5%-CVA: 6%; numbered EVs: 8.5%] and HEV-C [3.6%-CVA: 2.6%; numbered EVs: 1%] species, encompassing 63 genotypes. EV76 (6.3%) and each of E3, CVB3 and E9 (4.97%) were found frequently during 2009 while E11 (6.7%), CVB1 (6.1%), E7 (5.1%) and E20 (5.1%) were detected commonly in 2010. A marked proportion of AFP cases from children aged <2 years; presenting with fever; and from north and south interior parts of Karnataka state was detected with E/numbered EVs than that found with CVA/CVB. This study highlights the extensive genetic diversity and diverse circulation patterns of NPEV strains in AFP cases from different populations and climatic conditions.

Synthetic and Enhanced Vision System for Altair Lunar Lander

NASA Technical Reports Server (NTRS)

Prinzell, Lawrence J., III; Kramer, Lynda J.; Norman, Robert M.; Arthur, Jarvis J., III; Williams, Steven P.; Shelton, Kevin J.; Bailey, Randall E.

2009-01-01

Past research has demonstrated the substantial potential of synthetic and enhanced vision (SV, EV) for aviation (e.g., Prinzel & Wickens, 2009). These augmented visual-based technologies have been shown to significantly enhance situation awareness, reduce workload, enhance aviation safety (e.g., reduced propensity for controlled flight -into-terrain accidents/incidents), and promote flight path control precision. The issues that drove the design and development of synthetic and enhanced vision have commonalities to other application domains; most notably, during entry, descent, and landing on the moon and other planetary surfaces. NASA has extended SV/EV technology for use in planetary exploration vehicles, such as the Altair Lunar Lander. This paper describes an Altair Lunar Lander SV/EV concept and associated research demonstrating the safety benefits of these technologies.

Measurement of non-Maxwellian electron velocity distributions in a reflex discharge

NASA Technical Reports Server (NTRS)

Phipps, C. R., Jr.; Bershader, D.

1978-01-01

The results of a ruby laser Thomson scattering study of the space and time-resolved electron velocity distributions in a pulsed Penning discharge in hydrogen are presented. Electron densities were to the order of 10 to the 13th/cu cm and temperatures were roughly 3 eV. This point is just prior to the cessation of the discharge ohmic heating pulse. For magnetic strengths less than 200 G, Maxwellian distributions were found over an energy range six times thermal energy. Temperatures agreed with Langmuir probe data. For fields of 450 G, chaotic plasma potentials were observed to be unstable and the Thomson scattering showed that the electron velocity distributions had central temperatures of 2 eV and wing temperatures of 15-12 eV.

Boron Doped Nanocrystalline Film with Improved Work Function as a Buffer Layer in Thin Film Silicon Solar Cells.

PubMed

Park, Jinjoo; Shin, Chonghoon; Park, Hyeongsik; Jung, Junhee; Lee, Youn-Jung; Bong, Sungjae; Dao, Vinh Ai; Balaji, Nagarajan; Yi, Junsin

2015-03-01

We investigated thin film silicon solar cells with boron doped hydrogenated nanocrystalline silicon/ hydrogenated amorphous silicon oxide [p-type nc-Si:H/a-SiOx:H] layer. First, we researched the bandgap engineering of diborane (B2H6) doped wide bandgap hydrogenated nanocryslline silicon (p-type nc-Si:H) films, which have excellent electrical properties of high dark conductivity, and low activation energy. The films prepared with lower doping ratio and higher hydrogen dilution ratio had higher optical gap (Eg), with higher dark conductivity (σ(d)), and lower activation energy (Ea). We controlled Eg from 2.10 eV to 1.75 eV, with σ(d) from 1.1 S/cm to 7.59 x 10(-3) S/cm, and Ea from 0.040 eV to 0.128 eV. Next, we focused on the fabrication of thin film silicon solar cells. By inserting p-type nc-Si:H film into the thin film silicon solar cells, we achieved a remarkable increase in the built-in potential from 0.803 eV to 0.901 eV. By forming p-type nc-Si:H film between SnO2:F/ZnO:Al (30 nm) and p-type a-SiOx:H layer, the solar cell properties of open circuit voltage (Voc), short circuit current density (Jsc), and efficiency (η) were improved by 3.7%, 9.2%, and 9.8%, respectively.

Analysis of Fast Charging Station Network for Electrified Ride-Hailing Services

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, Eric W; Rames, Clement L; Kontou, Eleftheria

Today's electric vehicle (EV) owners charge their vehicles mostly at home and seldom use public direct current fast charger (DCFCs), reducing the need for a large deployment of DCFCs for private EV owners. However, due to the emerging interest among transportation network companies to operate EVs in their fleet, there is great potential for DCFCs to be highly utilized and become economically feasible in the future. This paper describes a heuristic algorithm to emulate operation of EVs within a hypothetical transportation network company fleet using a large global positioning system data set from Columbus, Ohio. DCFC requirements supporting operation ofmore » EVs are estimated using the Electric Vehicle Infrastructure Projection tool. Operation and installation costs were estimated using real-world data to assess the economic feasibility of the recommended fast charging stations. Results suggest that the hypothetical transportation network company fleet increases daily vehicle miles traveled per EV with less overall down time, resulting in increased demand for DCFC. Sites with overhead service lines are recommended for hosting DCFC stations to minimize the need for trenching underground service lines. A negative relationship was found between cost per unit of energy and fast charging utilization, underscoring the importance of prioritizing utilization over installation costs when siting DCFC stations. Although this preliminary analysis of the impacts of new mobility paradigms on alternative fueling infrastructure requirements has produced several key results, the complexity of the problem warrants further investigation.« less

Standardization of sample collection, isolation and analysis methods in extracellular vesicle research

PubMed Central

Witwer, Kenneth W.; Buzás, Edit I.; Bemis, Lynne T.; Bora, Adriana; Lässer, Cecilia; Lötvall, Jan; Nolte-‘t Hoen, Esther N.; Piper, Melissa G.; Sivaraman, Sarada; Skog, Johan; Théry, Clotilde; Wauben, Marca H.; Hochberg, Fred

2013-01-01

The emergence of publications on extracellular RNA (exRNA) and extracellular vesicles (EV) has highlighted the potential of these molecules and vehicles as biomarkers of disease and therapeutic targets. These findings have created a paradigm shift, most prominently in the field of oncology, prompting expanded interest in the field and dedication of funds for EV research. At the same time, understanding of EV subtypes, biogenesis, cargo and mechanisms of shuttling remains incomplete. The techniques that can be harnessed to address the many gaps in our current knowledge were the subject of a special workshop of the International Society for Extracellular Vesicles (ISEV) in New York City in October 2012. As part of the “ISEV Research Seminar: Analysis and Function of RNA in Extracellular Vesicles (evRNA)”, 6 round-table discussions were held to provide an evidence-based framework for isolation and analysis of EV, purification and analysis of associated RNA molecules, and molecular engineering of EV for therapeutic intervention. This article arises from the discussion of EV isolation and analysis at that meeting. The conclusions of the round table are supplemented with a review of published materials and our experience. Controversies and outstanding questions are identified that may inform future research and funding priorities. While we emphasize the need for standardization of specimen handling, appropriate normative controls, and isolation and analysis techniques to facilitate comparison of results, we also recognize that continual development and evaluation of techniques will be necessary as new knowledge is amassed. On many points, consensus has not yet been achieved and must be built through the reporting of well-controlled experiments. PMID:24009894

Mechanism for degradation of Nafion in PEM fuel cells from quantum mechanics calculations.

PubMed

Yu, Ted H; Sha, Yao; Liu, Wei-Guang; Merinov, Boris V; Shirvanian, Pezhman; Goddard, William A

2011-12-14

We report results of quantum mechanics (QM) mechanistic studies of Nafion membrane degradation in a polymer electrolyte membrane (PEM) fuel cell. Experiments suggest that Nafion degradation is caused by generation of trace radical species (such as OH(●), H(●)) only when in the presence of H(2), O(2), and Pt. We use density functional theory (DFT) to construct the potential energy surfaces for various plausible reactions involving intermediates that might be formed when Nafion is exposed to H(2) (or H(+)) and O(2) in the presence of the Pt catalyst. We find a barrier of 0.53 eV for OH radical formation from HOOH chemisorbed on Pt(111) and of 0.76 eV from chemisorbed OOH(ad), suggesting that OH might be present during the ORR, particularly when the fuel cell is turned on and off. Based on the QM, we propose two chemical mechanisms for OH radical attack on the Nafion polymer: (1) OH attack on the S-C bond to form H(2)SO(4) plus a carbon radical (barrier: 0.96 eV) followed by decomposition of the carbon radical to form an epoxide (barrier: 1.40 eV). (2) OH attack on H(2) crossover gas to form hydrogen radical (barrier: 0.04 eV), which subsequently attacks a C-F bond to form HF plus carbon radicals (barrier as low as 1.00 eV). This carbon radical can then decompose to form a ketone plus a carbon radical with a barrier of 0.86 eV. The products (HF, OCF(2), SCF(2)) of these proposed mechanisms have all been observed by F NMR in the fuel cell exit gases along with the decrease in pH expected from our mechanism. © 2011 American Chemical Society

RNA Profiles of Circulating Tumor Cells and Extracellular Vesicles for Therapy Stratification of Metastatic Breast Cancer Patients.

PubMed

Keup, Corinna; Mach, Pawel; Aktas, Bahriye; Tewes, Mitra; Kolberg, Hans-Christian; Hauch, Siegfried; Sprenger-Haussels, Markus; Kimmig, Rainer; Kasimir-Bauer, Sabine

2018-05-16

Liquid biopsies are discussed to provide surrogate markers for therapy stratification and monitoring. We compared messenger RNA (mRNA) profiles of circulating tumor cells (CTCs) and extracellular vesicles (EVs) in patients with metastatic breast cancer (MBC) to estimate their utility in therapy management. Blood was collected from 35 hormone receptor-positive/HER2-negative patients with MBC at the time of disease progression and at 2 consecutive staging time points. CTCs were isolated from 5 mL of blood by positive immunomagnetic selection, and EVs from 4 mL of plasma by a membrane affinity-based procedure. mRNA was reverse transcribed, preamplified, and analyzed for 18 genes by multimarker quantitative polymerase chain reaction (qPCR) assays. RNA profiles were normalized to healthy donor controls (n = 20), and results were correlated with therapy outcome. There were great differences in mRNA profiles of EVs and CTCs, with only 5% (21/403) of positive signals identical in both fractions. Transcripts involved in the PI3K signaling pathway were frequently overexpressed in CTCs, and AURKA , PARP1 , and SRC signals appeared more often in EVs. Of all patients, 40% and 34% showed ERBB2 and ERBB3 signals, respectively, in CTCs, which was significantly associated with disease progression ( P = 0.007). Whereas MTOR signals in CTCs significantly correlated with response ( P = 0.046), signals in EVs indicated therapy failure ( P = 0.011). The presence of AURKA signals in EVs seemed to be a marker for the indication of unsuccessful treatment of bone metastasis. These results emphasize the potential of CTCs and EVs for therapy monitoring and the need for critical evaluation of the implementation of any liquid biopsy in clinical practice. © 2018 American Association for Clinical Chemistry.

Hand, Foot, and Mouth Disease in China: Modeling Epidemic Dynamics of Enterovirus Serotypes and Implications for Vaccination

PubMed Central

Takahashi, Saki; Liao, Qiaohong; Van Boeckel, Thomas P.; Xing, Weijia; Sun, Junling; Hsiao, Victor Y.; Metcalf, C. Jessica E.; Chang, Zhaorui; Liu, Fengfeng; Zhang, Jing; Wu, Joseph T.; Cowling, Benjamin J.; Leung, Gabriel M.; Farrar, Jeremy J.; van Doorn, H. Rogier; Grenfell, Bryan T.; Yu, Hongjie

2016-01-01

Background Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus. Methods and Findings Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible–infected–recovered (TSIR) epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R 0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40) and 27.13 for CV-A16 (IQR: 23.15, 31.34), with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation). EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the post-EV-A71-vaccination period remained either comparable to or only slightly increased from levels prior to vaccination. The duration and strength of cross-protection following infection with EV-A71 or CV-A16 was estimated to be 9.95 wk (95% confidence interval [CI]: 3.31, 23.40) in 68% of the population (95% CI: 37%, 96%). Our predictions are limited by the necessarily short and under-sampled time series and the possible circulation of unidentified serotypes, but, nonetheless, sensitivity analyses indicate that our results are robust in predicting that the vaccine should drastically reduce incidence of EV-A71 without a substantial competitive release of CV-A16. Conclusions The ability of our models to capture the observed epidemic cycles suggests that herd immunity is driving the epidemic dynamics caused by the multiple serotypes of enterovirus. Our results predict that the EV-A71 and CV-A16 serotypes provide a temporary immunizing effect against each other. Achieving high coverage rates of EV-A71 vaccination would be necessary to eliminate the ongoing transmission of EV-A71, but serotype replacement by CV-A16 following EV-A71 vaccination is likely to be transient and minor compared to the corresponding reduction in the burden of EV-A71-associated HFMD. Therefore, a mass EV-A71 vaccination program of infants and young children should provide significant benefits in terms of a reduction in overall HFMD burden. PMID:26882540

Hand, Foot, and Mouth Disease in China: Modeling Epidemic Dynamics of Enterovirus Serotypes and Implications for Vaccination.

PubMed

Takahashi, Saki; Liao, Qiaohong; Van Boeckel, Thomas P; Xing, Weijia; Sun, Junling; Hsiao, Victor Y; Metcalf, C Jessica E; Chang, Zhaorui; Liu, Fengfeng; Zhang, Jing; Wu, Joseph T; Cowling, Benjamin J; Leung, Gabriel M; Farrar, Jeremy J; van Doorn, H Rogier; Grenfell, Bryan T; Yu, Hongjie

2016-02-01

Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus. Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible-infected-recovered (TSIR) epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40) and 27.13 for CV-A16 (IQR: 23.15, 31.34), with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation). EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the post-EV-A71-vaccination period remained either comparable to or only slightly increased from levels prior to vaccination. The duration and strength of cross-protection following infection with EV-A71 or CV-A16 was estimated to be 9.95 wk (95% confidence interval [CI]: 3.31, 23.40) in 68% of the population (95% CI: 37%, 96%). Our predictions are limited by the necessarily short and under-sampled time series and the possible circulation of unidentified serotypes, but, nonetheless, sensitivity analyses indicate that our results are robust in predicting that the vaccine should drastically reduce incidence of EV-A71 without a substantial competitive release of CV-A16. The ability of our models to capture the observed epidemic cycles suggests that herd immunity is driving the epidemic dynamics caused by the multiple serotypes of enterovirus. Our results predict that the EV-A71 and CV-A16 serotypes provide a temporary immunizing effect against each other. Achieving high coverage rates of EV-A71 vaccination would be necessary to eliminate the ongoing transmission of EV-A71, but serotype replacement by CV-A16 following EV-A71 vaccination is likely to be transient and minor compared to the corresponding reduction in the burden of EV-A71-associated HFMD. Therefore, a mass EV-A71 vaccination program of infants and young children should provide significant benefits in terms of a reduction in overall HFMD burden.

Evaluation of serum extracellular vesicle isolation methods for profiling miRNAs by next-generation sequencing

PubMed Central

Kotschote, Stefan; Bonin, Michael

2018-01-01

ABSTRACT Extracellular vesicles (EVs) are intercellular communicators with key functions in physiological and pathological processes and have recently garnered interest because of their diagnostic and therapeutic potential. The past decade has brought about the development and commercialization of a wide array of methods to isolate EVs from serum. Which subpopulations of EVs are captured strongly depends on the isolation method, which in turn determines how suitable resulting samples are for various downstream applications. To help clinicians and scientists choose the most appropriate approach for their experiments, isolation methods need to be comparatively characterized. Few attempts have been made to comprehensively analyse vesicular microRNAs (miRNAs) in patient biofluids for biomarker studies. To address this discrepancy, we set out to benchmark the performance of several isolation principles for serum EVs in healthy individuals and critically ill patients. Here, we compared five different methods of EV isolation in combination with two RNA extraction methods regarding their suitability for biomarker discovery-focused miRNA sequencing as well as biological characteristics of captured vesicles. Our findings reveal striking method-specific differences in both the properties of isolated vesicles and the ability of associated miRNAs to serve in biomarker research. While isolation by precipitation and membrane affinity was highly suitable for miRNA-based biomarker discovery, methods based on size-exclusion chromatography failed to separate patients from healthy volunteers. Isolated vesicles differed in size, quantity, purity and composition, indicating that each method captured distinctive populations of EVs as well as additional contaminants. Even though the focus of this work was on transcriptomic profiling of EV-miRNAs, our insights also apply to additional areas of research. We provide guidance for navigating the multitude of EV isolation methods available today and help researchers and clinicians make an informed choice about which strategy to use for experiments involving critically ill patients. PMID:29887978

Evaluation of serum extracellular vesicle isolation methods for profiling miRNAs by next-generation sequencing.

PubMed

Buschmann, Dominik; Kirchner, Benedikt; Hermann, Stefanie; Märte, Melanie; Wurmser, Christine; Brandes, Florian; Kotschote, Stefan; Bonin, Michael; Steinlein, Ortrud K; Pfaffl, Michael W; Schelling, Gustav; Reithmair, Marlene

2018-01-01

Extracellular vesicles (EVs) are intercellular communicators with key functions in physiological and pathological processes and have recently garnered interest because of their diagnostic and therapeutic potential. The past decade has brought about the development and commercialization of a wide array of methods to isolate EVs from serum. Which subpopulations of EVs are captured strongly depends on the isolation method, which in turn determines how suitable resulting samples are for various downstream applications. To help clinicians and scientists choose the most appropriate approach for their experiments, isolation methods need to be comparatively characterized. Few attempts have been made to comprehensively analyse vesicular microRNAs (miRNAs) in patient biofluids for biomarker studies. To address this discrepancy, we set out to benchmark the performance of several isolation principles for serum EVs in healthy individuals and critically ill patients. Here, we compared five different methods of EV isolation in combination with two RNA extraction methods regarding their suitability for biomarker discovery-focused miRNA sequencing as well as biological characteristics of captured vesicles. Our findings reveal striking method-specific differences in both the properties of isolated vesicles and the ability of associated miRNAs to serve in biomarker research. While isolation by precipitation and membrane affinity was highly suitable for miRNA-based biomarker discovery, methods based on size-exclusion chromatography failed to separate patients from healthy volunteers. Isolated vesicles differed in size, quantity, purity and composition, indicating that each method captured distinctive populations of EVs as well as additional contaminants. Even though the focus of this work was on transcriptomic profiling of EV-miRNAs, our insights also apply to additional areas of research. We provide guidance for navigating the multitude of EV isolation methods available today and help researchers and clinicians make an informed choice about which strategy to use for experiments involving critically ill patients.

Prohibitin plays a critical role in Enterovirus 71 neuropathogenesis

PubMed Central

Too, Issac Horng Khit; Bonne, Isabelle; Tan, Eng Lee; Chu, Justin Jang Hann; Alonso, Sylvie

2018-01-01

A close relative of poliovirus, enterovirus 71 (EV71) is regarded as an important neurotropic virus of serious public health concern. EV71 causes Hand, Foot and Mouth Disease and has been associated with neurological complications in young children. Our limited understanding of the mechanisms involved in its neuropathogenesis has hampered the development of effective therapeutic options. Here, using a two-dimensional proteomics approach combined with mass spectrometry, we have identified a unique panel of host proteins that were differentially and dynamically modulated during EV71 infection of motor-neuron NSC-34 cells, which are found at the neuromuscular junctions where EV71 is believed to enter the central nervous system. Meta-analysis with previously published proteomics studies in neuroblastoma or muscle cell lines revealed minimal overlapping which suggests unique host-pathogen interactions in NSC-34 cells. Among the candidate proteins, we focused our attention on prohibitin (PHB), a protein that is involved in multiple cellular functions and the target of anti-cancer drug Rocaglamide (Roc-A). We demonstrated that cell surface-expressed PHB is involved in EV71 entry into neuronal cells specifically, while membrane-bound mitochondrial PHB associates with the virus replication complex and facilitates viral replication. Furthermore, Roc-A treatment of EV71-infected neuronal cells reduced significantly virus yields. However, the inhibitory effect of Roc-A on PHB in NSC-34 cells was not through blocking the CRAF/MEK/ERK pathway as previously reported. Instead, Roc-A treated NSC-34 cells had lower mitochondria-associated PHB and lower ATP levels that correlated with impaired mitochondria integrity. In vivo, EV71-infected mice treated with Roc-A survived longer than the vehicle-treated animals and had significantly lower virus loads in their spinal cord and brain, whereas virus titers in their limb muscles were comparable to controls. Together, this study uncovers PHB as the first host factor that is specifically involved in EV71 neuropathogenesis and a potential drug target to limit neurological complications. PMID:29324904

Extracellular MicroRNA Signature of Human Helper T Cell Subsets in Health and Autoimmunity.

PubMed

Torri, Anna; Carpi, Donatella; Bulgheroni, Elisabetta; Crosti, Maria-Cristina; Moro, Monica; Gruarin, Paola; Rossi, Riccardo L; Rossetti, Grazisa; Di Vizio, Dolores; Hoxha, Mirjam; Bollati, Valentina; Gagliani, Cristina; Tacchetti, Carlo; Paroni, Moira; Geginat, Jens; Corti, Laura; Venegoni, Luigia; Berti, Emilio; Pagani, Massimiliano; Matarese, Giuseppe; Abrignani, Sergio; de Candia, Paola

2017-02-17

Upon T cell receptor stimulation, CD4 + T helper (Th) lymphocytes release extracellular vesicles (EVs) containing microRNAs. However, no data are available on whether human CD4 + T cell subsets release EVs containing different pattern of microRNAs. The present work aimed at filling this gap by assessing the microRNA content in EVs released upon in vitro T cell receptor stimulation of Th1, Th17, and T regulatory (Treg) cells. Our results indicate that EVs released by Treg cells are significantly different compared with those released by the other subsets. In particular, miR-146a-5p, miR-150-5p, and miR-21-5p are enriched, whereas miR-106a-5p, miR-155-5p, and miR-19a-3p are depleted in Treg-derived EVs. The in vitro identified EV-associated microRNA signature was increased in serum of autoimmune patients with psoriasis and returned to healthy levels upon effective treatment with etanercept, a biological drug targeting the TNF pathway and suppressing inflammation. Moreover, Gene Set Enrichment Analysis showed an over-representation of genes relevant for T cell activation, such as CD40L, IRAK1, IRAK2, STAT1, and c-Myb in the list of validated targets of Treg-derived EV miRNAs. At functional level, Treg-derived (but not Th1/Th17-derived) EVs inhibited CD4 + T cell proliferation and suppressed two relevant targets of miR-146a-5p: STAT1 and IRAK2. In conclusion, our work identified the miRNAs specifically released by different human CD4 + T cell subsets and started to unveil the potential use of their quantity in human serum to mark the pathological elicitation of these cells in vivo and their biological effect in cell to cell communication during the adaptive immune response. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Extracellular MicroRNA Signature of Human Helper T Cell Subsets in Health and Autoimmunity*

PubMed Central

Torri, Anna; Carpi, Donatella; Bulgheroni, Elisabetta; Crosti, Maria-Cristina; Moro, Monica; Gruarin, Paola; Rossi, Riccardo L.; Rossetti, Grazisa; Di Vizio, Dolores; Hoxha, Mirjam; Bollati, Valentina; Gagliani, Cristina; Tacchetti, Carlo; Paroni, Moira; Geginat, Jens; Corti, Laura; Venegoni, Luigia; Berti, Emilio; Pagani, Massimiliano; Matarese, Giuseppe; Abrignani, Sergio; de Candia, Paola

2017-01-01

Upon T cell receptor stimulation, CD4+ T helper (Th) lymphocytes release extracellular vesicles (EVs) containing microRNAs. However, no data are available on whether human CD4+ T cell subsets release EVs containing different pattern of microRNAs. The present work aimed at filling this gap by assessing the microRNA content in EVs released upon in vitro T cell receptor stimulation of Th1, Th17, and T regulatory (Treg) cells. Our results indicate that EVs released by Treg cells are significantly different compared with those released by the other subsets. In particular, miR-146a-5p, miR-150-5p, and miR-21-5p are enriched, whereas miR-106a-5p, miR-155-5p, and miR-19a-3p are depleted in Treg-derived EVs. The in vitro identified EV-associated microRNA signature was increased in serum of autoimmune patients with psoriasis and returned to healthy levels upon effective treatment with etanercept, a biological drug targeting the TNF pathway and suppressing inflammation. Moreover, Gene Set Enrichment Analysis showed an over-representation of genes relevant for T cell activation, such as CD40L, IRAK1, IRAK2, STAT1, and c-Myb in the list of validated targets of Treg-derived EV miRNAs. At functional level, Treg-derived (but not Th1/Th17-derived) EVs inhibited CD4+ T cell proliferation and suppressed two relevant targets of miR-146a-5p: STAT1 and IRAK2. In conclusion, our work identified the miRNAs specifically released by different human CD4+ T cell subsets and started to unveil the potential use of their quantity in human serum to mark the pathological elicitation of these cells in vivo and their biological effect in cell to cell communication during the adaptive immune response. PMID:28077577

Market mature 1998 hybrid electric vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wyczalek, F.A.

Beginning in 1990, the major automotive passenger vehicle manufacturers once again re-evaluated the potential of the battery powered electric vehicle (EV). This intensive effort to reduce the battery EV to commercial practice focused attention on the key issue of limited vehicle range, resulting from the low energy density and high mass characteristics of batteries, in comparison to the high energy density of liquid hydrocarbon (HC) fuels. Consequently, by 1995, vehicle manufacturers turned their attention to hybrid electric vehicles (HEV). This redirection of EV effort was highlighted finally, in 1997, at the 57th Frankfurt Motor Show, the Audi Duo parallel typemore » hybrid was released for the domestic market as a 1998 model vehicle. Also at the 1997 32nd Tokyo Motor Show, the Toyota Hybrid System (THS) Prius was released for the domestic market as a 1998 model vehicle. This paper presents a comparative analysis of the key features of these two 1998 model year production hybrid propulsion systems. Among the conclusions, two issues are evident: one, the major manufacturers have turned to the hybrid concept in their search for solutions to the key EV issues of limited range and heating/air conditioning; and, two, the focus is now on introducing hybrid EV for test marketing domestically.« less

Electron collisions with small esters: A joint experimental-theoretical investigation

NASA Astrophysics Data System (ADS)

de Souza, G. L. C.; da Silva, L. A.; de Sousa, W. J. C.; Sugohara, R. T.; Iga, I.; dos Santos, A. S.; Machado, L. E.; Homem, M. G. P.; Brescansin, L. M.; Lucchese, R. R.; Lee, M.-T.

2016-03-01

A theoretical and experimental investigation on elastic electron scattering by two small esters, namely, methyl formate and ethyl acetate, is reported. Experimental differential, integral, and momentum-transfer cross sections are given in the 30-1000 eV and 10∘-120∘ ranges. The relative-flow technique was used to determine such quantities. Particularly for methyl formate, a theoretical study was also carried out in the 1-500 eV range. A complex optical potential derived from a Hartree-Fock molecular wave function was used to represent the collision dynamics, whereas the Padé approximation was used to solve the scattering equations. In addition, calculations based on the framework of the independent-atom model (IAM) were also performed for both targets. In general, there is good agreement between our experimental data and the present theoretical results calculated using the Padé approximation. The theoretical results using the IAM also agree well with the experimental data at 200 eV and above. Moreover, for methyl formate, our calculations reveal a 2A'' (π*) resonance at about 3.0 eV and a σ*-type resonance centered at about 8.0 eV in the 2A' scattering channel. The π* resonance is also seen in other targets containing a carbonyl group.

Extracellular vesicles: their role in cancer biology and epithelial-mesenchymal transition.

PubMed

Gopal, Shashi K; Greening, David W; Rai, Alin; Chen, Maoshan; Xu, Rong; Shafiq, Adnan; Mathias, Rommel A; Zhu, Hong-Jian; Simpson, Richard J

2017-01-01

Cell-cell communication is critical across an assortment of physiological and pathological processes. Extracellular vesicles (EVs) represent an integral facet of intercellular communication largely through the transfer of functional cargo such as proteins, messenger RNAs (mRNAs), microRNA (miRNAs), DNAs and lipids. EVs, especially exosomes and shed microvesicles, represent an important delivery medium in the tumour micro-environment through the reciprocal dissemination of signals between cancer and resident stromal cells to facilitate tumorigenesis and metastasis. An important step of the metastatic cascade is the reprogramming of cancer cells from an epithelial to mesenchymal phenotype (epithelial-mesenchymal transition, EMT), which is associated with increased aggressiveness, invasiveness and metastatic potential. There is now increasing evidence demonstrating that EVs released by cells undergoing EMT are reprogrammed (protein and RNA content) during this process. This review summarises current knowledge of EV-mediated functional transfer of proteins and RNA species (mRNA, miRNA, long non-coding RNA) between cells in cancer biology and the EMT process. An in-depth understanding of EVs associated with EMT, with emphasis on molecular composition (proteins and RNA species), will provide fundamental insights into cancer biology. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

DFT study on dry reforming of methane over Ni2Fe overlayer of Ni(1 1 1) surface

NASA Astrophysics Data System (ADS)

Xu, Li-li; Wen, Hong; Jin, Xin; Bing, Qi-ming; Liu, Jing-yao

2018-06-01

We reported the complete catalytic cycle of dry reforming of methane (DRM) on Ni2Fe overlayer of Ni(1 1 1) surface by periodic density functional theory (DFT) calculations. The pathways for dehydrogenation of CH4 and CO2 activation were located. Our results demonstrate that compared with pure Ni(1 1 1) surface, the introduction Fe into Ni increases the energy barrier of CH dissociation to carbon and hydrogen atoms, thereby suppressing coke deposition on the surface, while it promotes the H-induced CO2 activation pathway to form OH radical, and thus not only the surface oxygen but also OH are responsible for the oxidation of CHx (x = 0,1) on the Ni2Fe overlayer. The most favorable pathway of CH/C oxidation is found to be CH∗ + OH∗ → CHOH∗ → CHO∗ + H∗ → CO∗ + 2H∗, with the rate-limiting energy barrier of 1.12 eV. Furthermore, since Fe is oxidized partially to FeO leading to a partial dealloying under DRM conditions, we also studied the surface-carbon removal and the activity for the reforming of methane on the FeO ribbon supported Ni(1 1 1) (FeO/Ni) interface by DFT+U method. The surface C reacts with lattice oxygen of FeO to produce CO via a Mars-van Krevelen (MvK) mechanism, with a very lower energy barrier of 0.16 eV. The present results show that the introduction of Fe into Ni has a positive effect on the activity toward DRM and has an improved coke resistance.

Purification and Identification of Membrane Proteins from Urinary Extracellular Vesicles using Triton X-114 Phase Partitioning.

PubMed

Hu, Shuiwang; Musante, Luca; Tataruch, Dorota; Xu, Xiaomeng; Kretz, Oliver; Henry, Michael; Meleady, Paula; Luo, Haihua; Zou, Hequn; Jiang, Yong; Holthofer, Harry

2018-01-05

Urinary extracellular vesicles (uEVs) have become a promising source for biomarkers accurately reflecting biochemical changes in kidney and urogenital diseases. Characteristically, uEVs are rich in membrane proteins associated with several cellular functions like adhesion, transport, and signaling. Hence, membrane proteins of uEVs should represent an exciting protein class with unique biological properties. In this study, we utilized uEVs to optimize the Triton X-114 detergent partitioning protocol targeted for membrane proteins and proceeded to their subsequent characterization while eliminating effects of Tamm-Horsfall protein, the most abundant interfering protein in urine. This is the first report aiming to enrich and characterize the integral transmembrane proteins present in human urinary vesicles. First, uEVs were enriched using a "hydrostatic filtration dialysis'' appliance, and then the enriched uEVs and lysates were verified by transmission electron microscopy. After using Triton X-114 phase partitioning, we generated an insoluble pellet fraction and aqueous phase (AP) and detergent phase (DP) fractions and analyzed them with LC-MS/MS. Both in- and off-gel protein digestion methods were used to reveal an increased number of membrane proteins of uEVs. After comparing with the identified proteins without phase separation as in our earlier publication, 199 different proteins were detected in DP. Prediction of transmembrane domains (TMDs) from these protein fractions showed that DP had more TMDs than other groups. The analyses of hydrophobicity revealed that the GRAVY score of DP was much higher than those of the other fractions. Furthermore, the analysis of proteins with lipid anchor revealed that DP proteins had more lipid anchors than other fractions. Additionally, KEGG pathway analysis showed that the DP proteins detected participate in endocytosis and signaling, which is consistent with the expected biological functions of membrane proteins. Finally, results of Western blotting confirmed that the membrane protein bands are found in the DP fraction instead of AP. In conclusion, our study validates the use of Triton X-114 phase partitioning protocol on uEVs for a targeted isolation of membrane proteins and to reduce sample complexity. This method successfully facilitates detection of potential biomarkers and druggable targets in uEVs.

Tracking an Unusual Carbapenemase-producing Organism from Drains to Patient Using Whole Genome Sequencing

PubMed Central

Ramsburg, Amanda M; Weingarten, Rebecca A; Conlan, Sean P; Dekker, John P; Michelin, Angela V; Odom, Robin T; Bordner, MaryAnn; Zellmer, Caroline J; Henderson, David K; Segre, Julia A; Frank, Karen M; Palmore, Tara N

2017-01-01

Abstract Background The NIH Clinical Center conducts patient and environmental surveillance for carbapenemase-producing organisms (CPO). Previous investigation revealed that sink drains can become colonized with CPO. Subsequent surveillance targets included potential aqueous reservoirs, such as floor drains of environmental services (EVS) closets. Methods Premoistened swabs were used to culture sink drains, floor drains, and equipment for CPO. Perirectal swabs were ordered monthly for all patients in non-behavioral health wards. Specimens were plated to CRE- and ESBL-selective media, and colonies identified by MALDI-TOF. The presence of the blaKPC gene was confirmed by PCR. When environmental CPO isolates were detected, EVS procedures and practices were reviewed. Results In June 2016, blaKPC+ Leclercia adecarboxylata was isolated from an EVS closet floor drain, and in August 2016, from drains in four additional closets. In the previous 10 years, Leclercia sp. was isolated just once from a clinical culture. In September 2016, routine surveillance revealed new-onset blaKPC+ L. adecarboxylata colonization in a stem cell transplant recipient. Investigation included 33 cultures collected from sink and floor drains, EVS equipment, and other items. EVS equipment, especially mop buckets, were identified as a likely point source due to their use in patient care areas and closets with contaminated floor drains. Among seven mop buckets sampled, one grew blaKPC+ L. adecarboxylata. Whole genome sequencing demonstrated genetic relatedness of the Leclercia isolates. Floor cleaner was changed to a disinfectant solution. Extensive decontamination of 67 EVS closets and equipment was performed urgently. No further patient or environmental cultures have grown blaKPC+ L. adecarboxylata. Conclusion The recovery of a highly unusual organism, rarely found in clinical specimens, that was also carrying a blaKPC+ plasmid, allowed us to detect environmental spread of this organism in the hospital. The ability to track this organism using genome sequencing provided strong evidence of the mode of spread, leading to effective remediation. No evidence-based methods exist for remediating drain contamination, which can serve as a potential reservoir for transmission. Disclosures All authors: No reported disclosures.

MiR-145 detection in urinary extracellular vesicles increase diagnostic efficiency of prostate cancer based on hydrostatic filtration dialysis method.

PubMed

Xu, Yong; Qin, Sihua; An, Taixue; Tang, Yueting; Huang, Yiyao; Zheng, Lei

2017-07-01

Extracellular vesicles (EVs) can be detected in body fluids and may serve as disease biomarkers. Increasing evidence suggests that circulating miRNAs in serum and urine may be potential non-invasive biomarkers for prostate cancer (PCa). In the present study, we aimed to investigate whether hydrostatic filtration dialysis (HFD) is suitable for urinary EVs (UEVs) isolation and whether such reported PCa-related miRNAs can be detected in UEVs as PCa biomarkers. To analyze EVs miRNAs, we searched for an easy and economic method to enrich EVs from urine samples. We compared the efficiency of HFD method and conventional ultracentrifugation (UC) in isolating UEVs. Subsequently, UEVs were isolated from patients with PCa, patients with benign prostate hyperplasia (BPH) and healthy individuals. Differential expression of four PCa-related miRNAs (miR-572, miR-1290, miR-141, and miR-145) were measured in UEVs and paired serum EVs using SYBR Green-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The overall performance of HFD was similar to UC. In miRNA yield, both HFD and UC can meet the needs of further analysis. The level of miR-145 in UEVs was significantly increased in patients with PCa compared with the patients with BPH (P = 0.018). In addition, significant increase was observed in miR-145 levels when patients with Gleason score ≥8 tumors compared with Gleason score ≤7 (P = 0.020). Receiver-operating characteristic curve (ROC) revealed that miR-145 in UEVs combined with serum PSA could differentiate PCa from BPH better than PSA alone (AUC 0.863 and AUC 0.805, respectively). In serum EVs, four miRNAs were significantly higher in patients with PCa than with BPH. HFD is appropriate for UEVs isolation and miRNA analysis when compared with conventional UC. miR-145 in UEVs is upregulated from PCa patients compared BPH patients and healthy controls. We suggest the potential use of UEVs miR-145 as a biomarker of PCa. © 2017 Wiley Periodicals, Inc.

Prediction of a two-dimensional S3N2 solid for optoelectronic applications

NASA Astrophysics Data System (ADS)

Xiao, Hang; Shi, Xiaoyang; Liao, Xiangbiao; Zhang, Yayun; Chen, Xi

2018-02-01

Two-dimensional materials have attracted tremendous attention for their fascinating electronic, optical, chemical, and mechanical properties. However, the band gaps of most reported two-dimensional (2D) materials are smaller than 2.0 eV, which has greatly restricted their optoelectronic applications in the blue and ultraviolet range of the spectrum. Here, we propose a stable trisulfur dinitride (S3N2 ) 2D crystal that is a covalent network composed solely of S-N σ bonds. The S3N2 crystal is dynamically, thermally, and chemically stable, as confirmed by the computed phonon spectrum and ab initio molecular dynamics simulations. GW calculations show that the S3N2 crystal is a wide, direct band-gap (3.92 eV) semiconductor with a small-hole effective mass. In addition, the band gap of S3N2 structures can be tuned by forming multilayer S3N2 crystals, S3N2 nanoribbons, and S3N2 nanotubes, expanding its potential applications. The anisotropic optical response of the 2D S3N2 crystal is revealed by GW-Bethe-Salpeter-equation calculations. The optical band gap of S3N2 is 2.73 eV and the exciton binding energy of S3N2 is 1.19 eV, showing a strong excitonic effect. Our result not only marks the prediction of a 2D crystal composed of nitrogen and sulfur, but also underpins potential innovations in 2D electronics and optoelectronics.

Developing porous carbon with dihydrogen phosphate groups as sulfur host for high performance lithium sulfur batteries

NASA Astrophysics Data System (ADS)

Cui, Yanhui; Zhang, Qi; Wu, Junwei; Liang, Xiao; Baker, Andrew P.; Qu, Deyang; Zhang, Hui; Zhang, Huayu; Zhang, Xinhe

2018-02-01

Carbon matrix (CM) derived from biomass is low cost and easily mass produced, showing great potential as sulfur host for lithium sulfur batteries. In this paper we report on a dihydrogen phosphate modified CM (PCM-650) prepared from luffa sponge (luffa acutangula) by phosphoric acid treatment. The phosphoric acid not only increases the surface area of the PCM-650, but also introduces dihydrogen phosphate onto PCM-650 (2.28 at% P). Sulfur impregnated (63.6 wt%) PCM-650/S, in comparison with samples with less dihydrogen phosphate LPCM-650/S, shows a significant performance improvement. XPS analysis is conducted for sulfur at different stages, including sulfur (undischarged), polysulfides (discharge to 2.1 V) and short chain sulfides (discharge to 1.7 V). The results consistently show chemical shifts for S2p in PCM-650, suggesting an enhanced adsorption effect. Furthermore, density functional theory (DFT) calculations is used to clarify the molecular binding: carbon/sulfur (0.86 eV), carbon/Li2S (0.3 eV), CH3-O-PO3H2/sulfur (1.24 eV), and CH3-O-PO3H2/Li2S (1.81 eV). It shows that dihydrogen phosphate group can significantly enhance the binding with sulfur and sulfide, consistent with XPS results. Consequently a CM functionalised with dihydrogen phosphate shows great potential as the sulfur host in a Li-S battery.

The Role of Exosomes in Breast Cancer.

PubMed

Lowry, Michelle C; Gallagher, William M; O'Driscoll, Lorraine

2015-12-01

Although it has been long realized that eukaryotic cells release complex vesicular structures into their environment, only in recent years has it been established that these entities are not merely junk or debris, but that they are tailor-made specialized minimaps of their cell of origin and of both physiological and pathological relevance. These exosomes and microvesicles (ectosomes), collectively termed extracellular vesicles (EVs), are often defined and subgrouped first and foremost according to size and proposed origin (exosomes approximately 30-120 nm, endosomal origin; microvesicles 120-1000 nm, from the cell membrane). There is growing interest in elucidating the relevance and roles of EVs in cancer. Much of the pioneering work on EVs in cancer has focused on breast cancer, possibly because breast cancer is a leading cause of cancer-related deaths worldwide. This review provides an in-depth summary of such studies, supporting key roles for exosomes and other EVs in breast cancer cell invasion and metastasis, stem cell stimulation, apoptosis, immune system modulation, and anti-cancer drug resistance. Exosomes as diagnostic, prognostic, and/or predictive biomarkers and their potential use in the development of therapeutics are discussed. Although not fully elucidated, the involvement of exosomes in breast cancer development, progression, and resistance is becoming increasingly apparent from preclinical and clinical studies, with mounting interest in the potential exploitation of these vesicles for breast cancer biomarkers, as drug delivery systems, and in the development of future novel breast cancer therapies. © 2015 American Association for Clinical Chemistry.

First principles study of structural, electronic and optical properties of perovskites CaZrO3 and CaHfO3 in cubic phase

NASA Astrophysics Data System (ADS)

Hoat, D. M.; Silva, J. F. Rivas; Blas, A. Méndez

2018-07-01

In this work, we present the first principles calculations for structural, electronic and optical properties of perovskites CaZrO3 and CaHfO3 using the full-potential linearized augmented plane wave method (FP-LAPW) within the framework of density functional theory (DFT) as implemented in WIEN2k package. The exchange-correlation potential is treated with local density approximation (LDA) and generalized gradient approximation (GGA-PBE and PBESol). Additionally, the Tran Blaha modified Becke-Johnson exchange potential (mBJ) also is employed for electronic and optical calculations due to that it gives very accurate band gap of solids. Our obtained structural parameters are in good agreement with experimental datas and other theoretical results. The energy band gap obtained with mBJ is 4.56 eV for CaZrO3 and 5.27 eV for CaHfO3. The hybridization of states of O atom with those of Zr and Hf atoms in CaZrO3 and CaHfO3, respectively, is observed. The spin-orbit coupling effect on electronic properties of considered compounds also is investigated. Finally, the linear optical properties of CaZrO3 and CaHfO3 are derived from their complex dielectric function calculated with mBJ potential for wide energy range up to 45 eV, and all of them analyzed in details.

Supercharging of the Lunar Surface by Solar Wind Halo Electrons

NASA Astrophysics Data System (ADS)

Stubbs, T. J.; Farrell, W. M.; Collier, M. R.; Halekas, J. S.; Delory, G. T.; Holland, M. P.; Vondrak, R. R.

2007-12-01

Lunar surface potentials can reach several kilovolts negative during Solar Energetic Particle (SEPs) events, as indicated by recent analysis of data from the Lunar Prospector Electron Reflectometer (LP/ER). The lunar surface- plasma interactions that result in such extreme surface potentials are poorly characterized and understood. Extreme lunar surface charging, and the associated electrostatic discharges and transport of charged dust, will likely present significant hazards to future human explorers. This is of particular concern near the terminator and polar regions, such as the South Pole/Aiken Basin site planned for NASA's manned outpost. It is the flux of electrons from the ambient plasma that charges the surface of the Moon to negative potentials. In the solar wind, the electron temperature is typically ~10 eV which tends to charge the lunar surface to ~100 V negative in shadow. However, during space weather events the solar wind electrons are often better described by the sum of two Maxwellian distributions, referred to as the "core" and "halo" components. The core electrons are relatively cool and dense (e.g., ~10 eV and ~10/cc), whereas the halo electrons are hot and tenuous (e.g., ~100 eV and ~0.1/cc). Despite, the tenuous nature of the halo electrons, our surface charging model - using core and halo electron data derived from the Solar Wind Experiment (SWE) aboard the Wind spacrcraft - predicts that they are capable of "supercharging" the lunar surface to kilovolt potentials during space weather events, which could explain the LP/ER observations.

STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF PET POLYMER FILMS MODIFIED BY LOW ENERGY Ar+ ION BEAMS

NASA Astrophysics Data System (ADS)

Fawzy, Y. H. A.; Abdel-Hamid, H. M.; El-Okr, M. M.; Atta, A.

Polyethylene terephthalate (PET) films with thickness 40μm are irradiated with 3keV argon ion beams with different fluence ranging from 0.5×1018ions.cm-2 to 2×1018ions.cm-2 using locally designed broad ion source. The changes in the PET structure are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscope (SEM) techniques. The XRD patterns show that the peak intensity decreases with irradiation and the particle size decreases from 65.75 Å for the un-irradiated to 52.80 Å after irradiation. The FTIR indicates partial decrease and reduction in the intensity of the bands due to the degradation of the polymer after ion irradiation. The optical energy band gap decreases from 3.14eV to 3.05eV and the number of carbon cluster increases from 119 to 126 after ion irradiation. The results show a slight increase in the electrical conductivities and the dielectric constant (ɛ). The results indicate the effectiveness of using PET films as capacitors and resistors in industrial applications.

Evidence for Weakly Correlated Oxygen Holes in the Highest-Tc Cuprate Superconductor HgBa2 Ca2 Cu3 O8 +δ

NASA Astrophysics Data System (ADS)

Chainani, A.; Sicot, M.; Fagot-Revurat, Y.; Vasseur, G.; Granet, J.; Kierren, B.; Moreau, L.; Oura, M.; Yamamoto, A.; Tokura, Y.; Malterre, D.

2017-08-01

We study the electronic structure of HgBa2 Ca2 Cu3 O8 +δ (Hg1223; Tc=134 K ) using photoemission spectroscopy (PES) and x -ray absorption spectroscopy (XAS). Resonant valence band PES across the O K edge and Cu L edge identifies correlation satellites originating in O 2 p and Cu 3 d two-hole final states, respectively. Analyses using the experimental O 2 p and Cu 3 d partial density of states show quantitatively different on-site Coulomb energy for the Cu site (Ud d=6.5 ±0.5 eV ) and O site (Up p=1.0 ±0.5 eV ). Cu2 O7 -cluster calculations with nonlocal screening explain the Cu 2 p core level PES and Cu L -edge XAS spectra, confirm the Ud d and Up p values, and provide evidence for the Zhang-Rice singlet state in Hg1223. In contrast to other hole-doped cuprates and 3 d -transition metal oxides, the present results indicate weakly correlated oxygen holes in Hg1223.

Lattice sites of ion-implanted Mn, Fe and Ni in 6H-SiC

NASA Astrophysics Data System (ADS)

Costa, A. R. G.; Wahl, U.; Correia, J. G.; David-Bosne, E.; Amorim, L. M.; Augustyns, V.; Silva, D. J.; da Silva, M. R.; Pereira, L. M. C.

2018-01-01

Using radioactive isotopes produced at the CERN-ISOLDE facility, the lattice location of the implanted transition metal (TM) ions 56Mn, 59Fe and 65Ni in n-type single-crystalline hexagonal 6H-SiC was studied by means of the emission channeling technique. TM probes on carbon coordinated tetrahedral interstitial sites (T C) and on substitutional silicon sites (S Si,h+k ) were identified. We tested for but found no indication that the TM distribution on S Si sites deviates from the statistical mixture of 1/3 hexagonal and 2/3 cubic sites present in the 6H crystal. The TM atoms partially disappear from T C positions during annealing at temperatures between 500 °C and 700 °C which is accompanied by an increase on S Si and random sites. From the temperature associated with these site changes, interstitial migration energies of 1.7-2.7 eV for Mn and Ni, and 2.3-3.2 eV for Fe were estimated. TM lattice locations are compared to previous results obtained in 3C-SiC using the same technique.

Chasing the light sterile neutrino with the STEREO detector

NASA Astrophysics Data System (ADS)

Minotti, A.

2017-09-01

The standard three-family neutrino oscillation model is challenged by a number of observations, such as the reactor antineutrino anomaly (RAA), that can be explained by the existence of sterile neutrinos at the eV mass scale. The STEREO experiment detects {\\bar ν _e} produced in the 58.3MW Th compact core of the ILL research reactor via inverse beta decay (IBD) interactions in a liquid scintillator. Using 6 identical target cells, STEREO compares {\\bar ν _e} energy spectra at different baselines in order to observe possible distortions due to short-baseline oscillations toward eV sterile neutrinos. IBD events are effectively singled out from γ radiation by selecting events with a two-fold coincidence that is typical of an IBD interaction. External background is reduced by means of layers of shielding material. A Cherenkov veto allows to partially remove background produced by cosmic muons, and the remaining component is measured in reactor-off periods and subtracted statistically. If no evidence of sterile neutrinos after the full statistics of 6 reactor cycles is gathered, STEREO is expected to fully exclude the RAA allowed region.

Partial-wave analysis for positronium-xenon collisions in the ultralow-energy region

NASA Astrophysics Data System (ADS)

Shibuya, Kengo; Saito, Haruo

2018-05-01

We propose a method to convert measured positronium annihilation rates in gaseous xenon into total and differential cross sections of positronium-xenon collisions in an ultralow-energy region of less than 80 meV where their experimental determinations as functions of the positronium kinetic energy are extremely difficult. This method makes it possible to determine not only the s -wave collisional parameters but also the p -wave and d -wave parameters. We have found a small positive value of the scattering length, A0=2.06 ±0.10 a0 , which indicates that the positronium-xenon interaction in this energy region is repulsive and suggests that it is dominated by the scattering amplitude of the positron rather than that of the electron. An extrapolation of the analytical result into the experimentally inaccessible energy regions from 80 meV to 1.0 eV indicates that there should not be a Ramsauer-Townsend minimum but rather a peak in the total cross section at an energy of approximately 0.4 eV.

Controlling the electronic structure of graphene using surface-adsorbate interactions

DOE PAGES

Matyba, Piotr; Carr, Adra; Chen, Cong; ...

2015-07-15

Hybridization of atomic orbitals in graphene on Ni(111) opens up a large energy gap of ≈2.8eV between nonhybridized states at the K point. Here we use alkali-metal adsorbate to reduce and even eliminate this energy gap, and also identify a new mechanism responsible for decoupling graphene from the Ni substrate without intercalation of atomic species underneath. Using angle-resolved photoemission spectroscopy and density functional theory calculations, we show that the energy gap is reduced to 1.3 eV due to moderate decoupling after adsorption of Na on top of graphene. Calculations confirm that after adsorption of Na, graphene bonding to Ni ismore » much weaker due to a reduced overlap of atomic orbitals, which results from n doping of graphene. Finally, we show that the energy gap is eliminated by strong decoupling resulting in a quasifreestanding graphene, which is achieved by subsequent intercalation of the Na underneath graphene. Furthermore, the ability to partially decouple graphene from a Ni substrate via n doping, with or without intercalation, suggests that the graphene-to-substrate interaction could be controlled dynamically.« less

Dry reforming of methane on a highly-active Ni-CeO 2 catalyst: Effects of metal-support interactions on C–H bond breaking

DOE PAGES

Liu, Zongyuan; Grinter, David C.; Lustemberg, Pablo G.; ...

2016-05-04

Ni-CeO 2 is a highly efficient, stable and non-expensive catalyst for methane dry reforming at relative low temperatures (700 K). The active phase of the catalyst consists of small nanoparticles of nickel dispersed on partially reduced ceria. Experiments of ambient pressure XPS indicate that methane dissociates on Ni/CeO 2 at temperatures as low as 300 K, generating CH x and CO x species on the surface of the catalyst. Strong metal–support interactions activate Ni for the dissociation of methane. The results of density-functional calculations show a drop in the effective barrier for methane activation from 0.9 eV on Ni(111) tomore » only 0.15 eV on Ni/CeO 2–x(111). At 700 K, under methane dry reforming conditions, no signals for adsorbed CH x or C species are detected in the C1s XPS region. As a result, the reforming of methane proceeds in a clean and efficient way.« less

Close genetic relatedness of picornaviruses from European and Asian bats.

PubMed

Lukashev, Alexander N; Corman, Victor Max; Schacht, Daniel; Gloza-Rausch, Florian; Seebens-Hoyer, Antje; Gmyl, Anatoly P; Drosten, Christian; Drexler, Jan Felix

2017-05-01

Our investigation of 1004 faecal specimens from European bats for picornaviruses by broadly reactive nested reverse transcription-PCR found picornaviral RNA in 28 samples (2.8 %). Phylogenetic analysis of the partial 3D genomic region suggested that one bat virus belonged to the species Enterovirus G (EV-G, formerly Porcine enterovirus B). Bat infection was supported by relatively high EV-G concentrations of 1.1×106 RNA copies per gram of faeces. All other bat viruses belonged either to the bat-associated genus Mischivirus, or to an unclassified Picornaviridae group distantly related to the genus Sapelovirus. Members of this unclassified sapelovirus-related group had RNA secondary structures in their 3'-nontranslated regions that were typical of enteroviruses and that resembled structures that occur in bat-associated coronaviruses, suggesting ancient recombination events. Based on sequence distances, several picornaviruses from European and Chinese bats were likely conspecific, suggesting connectivity of virus populations. Due to their high mutation rates and their diversity, picornaviruses may be useful tools for studies of bat and virus ecology.

Greater decision-making competence is associated with greater expected-value sensitivity, but not overall risk taking: an examination of concurrent validity.

PubMed

Parker, Andrew M; Weller, Joshua A

2015-01-01

Decision-making competence reflects individual differences in the susceptibility to committing decision-making errors, measured using tasks common from behavioral decision research (e.g., framing effects, under/overconfidence, following decision rules). Prior research demonstrates that those with higher decision-making competence report lower incidence of health-risking and antisocial behaviors, but there has been less focus on intermediate processes that may impact real-world decisions, and, in particular, those implicated by normative models. Here we test the associations between measures of youth decision-making competence (Y-DMC) and one such process, the degree to which individuals make choices consistent with maximizing expected value (EV). Using a task involving hypothetical gambles, we find that greater EV sensitivity is associated with greater Y-DMC. Higher Y-DMC scores are associated with (a) choosing risky options when EV favors those options and (b) avoiding risky options when EV favors a certain option. This relationship is stronger for gambles that involved potential losses. The results suggest that Y-DMC captures decision processes consistent with standard normative evaluations of risky decisions.

Excitons emissions and Raman scattering of ZnO nanoparticles embedded in BaF2 matrices by reactive magnetron sputtering.

PubMed

Zang, C H; Su, J F; Liu, Y C; Tang, C J; Fang, S J; Zhang, D M; Zhang, Y S

2011-11-01

ZnO nanoparticles embedded in BaF2 matrix were fabricated by rf magnetic sputtering technology. The optical properties of high quality ZnO nanoparticles, thermally post treated in a N2 atmosphere, were investigated by temperature-dependence photoluminescence measurement. Free exciton and localized exciton were observed at the low temperature. Free exciton peak was at 3.374 eV and localized exciton peak was at 3.420 eV, dominating the PL spectrum at 77 K. Free exciton transition was observed at 3.310 eV at room temperature, whereas the localized exciton transition was at 3.378 eV. The multiple-phonon Raman scattering spectrum showed that ZnO nanoparticles embedded in BaF2 matrix had a large deformation energy originated from lattice mismatch between ZnO and BaF2 matrix. Analysis of the fitting results from the temperature dependence of FWHM of ZnO exciton illustrated that the large value of gamma(ph) was good qualitative agreement with the large deformation potential.

Band gap engineering of hydrogenated amorphous carbon thin films for solar cell application

NASA Astrophysics Data System (ADS)

Dwivedi, Neeraj; Kumar, Sushil; Dayal, Saurabh; Rauthan, C. M. S.; Panwar, O. S.; Malik, Hitendra K.

2012-10-01

In this work, self bias variation, nitrogen introduction and oxygen plasma (OP) treatment approaches have been used for tailoring the band gap of hydrogenated amorphous carbon (a-C:H) thin films. The band gap of a-C:H and modified a- C:H films is varied in the range from 1.25 eV to 3.45 eV, which is found to be nearly equal to the full solar spectrum (1 eV- 3.5 eV). Hence, such a-C:H and modified a-C:H films are found to be potential candidate for the development of full spectrum solar cells. Besides this, computer aided simulation with considering variable band gap a-C:H and modified a- C:H films as window layer for amorphous silicon p-i-n solar cells is also performed by AFORS-HET software and maximum efficiency as ~14 % is realized. Since a-C:H is hard material, hence a-C:H and modified a-C:H films as window layer may avoid the use of additional hard and protective coating particularly in n-i-p configuration.

Prediction of Protection against Asian Enterovirus 71 Outbreak Strains by Cross-neutralizing Capacity of Serum from Dutch Donors, The Netherlands

PubMed Central

Koen, Gerrit; van Eijk, Hetty; Koekkoek, Sylvie M.; de Jong, Menno D.; Wolthers, Katja C.

2016-01-01

Outbreaks of human enterovirus 71 (EV-71) in Asia are related to high illness and death rates among children. To gain insight into the potential threat for the population of Europe, we determined the neutralizing activity in intravenous immunoglobulin (IVIg) batches and individual serum samples from donors in the Netherlands against EV-71 strains isolated in Europe and in Asia. All IVIg batches and 41%, 79%, and 65% of serum samples from children ≤5 years of age, women of childbearing age, and HIV-positive men, respectively, showed high neutralizing activity against a Dutch C1 strain, confirming widespread circulation of EV-71 in the Netherlands. Asian B3–4 and C4 strains were efficiently cross-neutralized, predicting possible protection against extensive circulation and associated outbreaks of those types in Europe. However, C2 and C5 strains that had few mutations in the capsid region consistently escaped neutralization, emphasizing the importance of monitoring antigenic diversity among circulating EV-71 strains. PMID:27533024

The impact of proteomics on the understanding of functions and biogenesis of fungal extracellular vesicles.

PubMed

Rodrigues, Marcio L; Nakayasu, Ernesto S; Almeida, Igor C; Nimrichter, Leonardo

2014-01-31

Several microbial molecules are released to the extracellular space in vesicle-like structures. In pathogenic fungi, these molecules include pigments, polysaccharides, lipids, and proteins, which traverse the cell wall in vesicles that accumulate in the extracellular space. The diverse composition of fungal extracellular vesicles (EV) is indicative of multiple mechanisms of cellular biogenesis, a hypothesis that was supported by EV proteomic studies in a set of Saccharomyces cerevisiae strains with defects in both conventional and unconventional secretory pathways. In the human pathogens Cryptococcus neoformans, Histoplasma capsulatum, and Paracoccidioides brasiliensis, extracellular vesicle proteomics revealed the presence of proteins with both immunological and pathogenic activities. In fact, fungal EV have been demonstrated to interfere with the activity of immune effector cells and to increase fungal pathogenesis. In this review, we discuss the impact of proteomics on the understanding of functions and biogenesis of fungal EV, as well as the potential role of these structures in fungal pathogenesis. This article is part of a Special Issue entitled: Trends in Microbial Proteomics. Copyright © 2013 Elsevier B.V. All rights reserved.

Control Issues.

ERIC Educational Resources Information Center

Olsen, Florence

2003-01-01

Discusses how the potential effectiveness of Palladium, Microsoft's new approach to computer security, is worrying academics, who say it could allow publishers to dam the free flow of online information. (EV)

Hydrogen bond asymmetric local potentials in compressed ice.

PubMed

Huang, Yongli; Ma, Zengsheng; Zhang, Xi; Zhou, Guanghui; Zhou, Yichun; Sun, Chang Q

2013-10-31

A combination of the Lagrangian mechanics of oscillators vibration, molecular dynamics decomposition of volume evolution, and Raman spectroscopy of phonon relaxation has enabled us to resolve the asymmetric, local, and short-range potentials pertaining to the hydrogen bond (O:H-O) in compressed ice. Results show that both oxygen atoms in the O:H-O bond shift initially outwardly with respect to the coordination origin (H), lengthening the O-O distance by 0.0136 nm from 0.2597 to 0.2733 nm by Coulomb repulsion between electron pairs on adjacent oxygen atoms. Both oxygen atoms then move toward right along the O:H-O bond by different amounts upon being compressed, approaching identical length of 0.11 nm. The van der Waals potential VL(r) for the O:H noncovalent bond reaches a valley at -0.25 eV, and the lowest exchange VH(r) for the H-O polar-covalent bond is valued at -3.97 eV.

Structure, Immunogenicity, and Protective Mechanism of an Engineered Enterovirus 71-Like Particle Vaccine Mimicking 80S Empty Capsid.

PubMed

Wang, Xiaoli; Ku, Zhiqiang; Zhang, Xiang; Ye, Xiaohua; Chen, Jinhuan; Liu, Qingwei; Zhang, Wei; Zhang, Chao; Fu, Zhenglin; Jin, Xia; Cong, Yao; Huang, Zhong

2018-01-01

Enterovirus 71 (EV71) is the major causative agent of severe hand, foot, and mouth disease, which affects millions of young children in the Asia-Pacific region annually. In this study, we engineered a novel EV71 virus-like particle (VLP) that lacks VP4 (therefore designated VLP ΔVP4 ) and investigated its structure, antigenicity, and vaccine potential. The cryo-electron microscopy (cryo-EM) structure of VLP ΔVP4 was reconstructed to 3.71-Å resolution. Results from structural and biochemical analyses revealed that VLP ΔVP4 resembles the end product of the viral uncoating process, the 80S empty capsid. VLP ΔVP4 is able to elicit high-titer neutralizing antibodies and to fully protect mice against lethal viral challenge. Mechanistic studies showed that, at the cellular level, the anti-VLP ΔVP4 sera exert neutralization effects at both pre- and postattachment stages by inhibiting both virus attachment and internalization, and at the molecular level, the antisera can block multiple interactions between EV71 and its key receptors. Our study gives a better understanding of EV71 capsid assembly and provides important information for the design and development of new-generation vaccines for EV71, and perhaps for other enteroviruses, as well. IMPORTANCE Enterovirus 71 (EV71) infection may lead to severe hand, foot, and mouth disease, with significant morbidity and mortality. Knowledge regarding EV71 particle assembly remains limited. Here, we report the generation and characterization of a novel EV71 virus-like particle that lacks the VP4 capsid subunit protein. This particle, termed VLP ΔVP4 , structurally mimics the 80S empty capsid, which is the end stage of EV71 uncoating. We further show that VLP ΔVP4 exhibits desirable immunogenicity and protective efficacy in proof-of-concept studies. In addition, the inhibitory mechanisms of the VLP ΔVP4 -induced antibodies are unraveled at both the cellular and molecular levels. Our work provides the first evidence of picornaviral particle assembly in the complete absence of VP4 and identifies VLP ΔVP4 as an improved EV71 vaccine candidate with desirable traits. These findings not only enhance our understanding of particle assembly and uncoating of picornaviruses, but also provide important information for structure-guided vaccine design for EV71 and other enteroviruses. Copyright © 2017 American Society for Microbiology.

Upward electron beams measured by DE-1 - A primary source of dayside region-1 Birkeland currents

NASA Technical Reports Server (NTRS)

Burch, J. L.; Reiff, P. H.; Sugiura, M.

1983-01-01

Measurements made by the High Altitude Plasma Instrument on DE-1 have shown that intense upward electron beams with energies from about 20 eV to about 200 eV are a common feature of the region just equatorward of the morning-side polar cusp. Computations of the currents carried by these beams and by the precipitating cusp electrons show excellent agreement with the simultaneous DE-1 magnetometer measurements for both upward and downward Birkeland currents. The data indicate that cold ionospheric electrons, which carry the downward region-1 Birkeland currents on the morning side, are accelerated upward by potential drops of a few tens of eV at altitudes of several thousand kilometers. This acceleration process allows spacecraft above those altitudes to measure routinely the charge carriers of both downward and upward current systems.

HSP-enriched properties of extracellular vesicles involve survival of metastatic oral cancer cells.

PubMed

Ono, Kisho; Eguchi, Takanori; Sogawa, Chiharu; Calderwood, Stuart K; Futagawa, Junya; Kasai, Tomonari; Seno, Masaharu; Okamoto, Kuniaki; Sasaki, Akira; Kozaki, Ken-Ichi

2018-05-16

Cancer cells often secrete extracellular vesicles (EVs) that carry heat shock proteins (HSPs) with roles in tumor progression. Oral squamous cell carcinoma (OSCC) belongs to head and neck cancers (HNC) whose lymph-node-metastases often lead to poor prognosis. We have examined the EV proteome of OSCC cells and found abundant secretion of HSP90-enriched EVs in lymph-node-metastatic OSCC cells. Double knockdown of HSP90α and HSP90β, using small interfering RNA significantly reduced the survival of the metastatic OSCC cells, although single knockdown of each HSP90 was ineffective. Elevated expression of these HSP90 family members was found to correlate with poor prognosis of HNC cases. Thus, elevated HSP90 levels in secreted vesicles are potential prognostic biomarkers and therapeutic targets in metastatic OSCC. © 2018 Wiley Periodicals, Inc.

Theoretical surface core-level shifts for Be(0001)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feibelman, P.J.

1994-05-15

Core-ionization potentials (CIP's) are computed for Be(0001). Three core features are observed in corresponding photoelectron spectra, with CIP's shifted relative to the bulk core level by [minus]0.825, [minus]0.570, and [minus]0.265 eV. The computed CIP shifts for the outer and subsurface layers, [minus]0.60 and [minus]0.29 eV, respectively, agree with the latter two of these. It is surmised that the [minus]0.825-eV shift is associated with a surface defect. The negative signs of the Be(0001) surface core-level shifts do not fit into the thermochemical picture widely used to explain CIP shifts. The reason is that a core-ionized Be atom is too small tomore » bond effectively to the remainder of the unrelaxed Be lattice.« less

Enhancement of Thermoelectric Performances in a Topological Crystal Insulator Pb0.7Sn0.3Se via Weak Perturbation of the Topological State and Chemical Potential Tuning by Chlorine Doping.

PubMed

Lin, Chan-Chieh; Kim, Gareoung; Ginting, Dianta; Ahn, Kyunghan; Rhyee, Jong-Soo

2018-04-04

Topological insulators generally share commonalities with good thermoelectric (TE) materials because of their narrow band gaps and heavy constituent elements. Here, we propose that a topological crystalline insulator (TCI) could exhibit a high TE performance by breaking its crystalline symmetry and tuning the chemical potential by elemental doping. As a candidate material, we investigate the TE properties of the Cl-doped TCI Pb 0.7 Sn 0.3 Se. The infrared absorption spectra reveal that the band gap is increased from 0.055 eV for Pb 0.7 Sn 0.3 Se to 0.075 eV for Pb 0.7 Sn 0.3 Se 0.99 Cl 0.01 , confirming that the Cl doping can break the crystalline mirror symmetry of a TCI Pb 0.7 Sn 0.3 Se and thereby enlarge its bulk electronic band gap. The topological band inversion is confirmed by the extended X-ray absorption fine structure spectroscopy, which shows that the TCI state is weakened in a chlorine x = 0.05-doped compound. The small gap opening and partial linear band dispersion with massless and massive bands may have a high power factor (PF) for high electrical conductivity with an enhancement of the Seebeck coefficient. As a result, Pb 0.7 Sn 0.3 Se 0.99 Cl 0.01 shows a considerably enhanced ZT of 0.64 at 823 K, which is about 1200% enhancement in ZT compared with that of the undoped Pb 0.7 Sn 0.3 Se. This work demonstrates that the optimal n-type Cl doping tunes the chemical potential together with breaking the state of the TCI, suppresses the bipolar conduction at high temperatures, and thereby enables the Seebeck coefficient to increase up to 823 K, resulting in a significantly enhanced PF at high temperatures. In addition, the bipolar contribution to thermal conductivity is effectively suppressed for the Cl-doped samples of Pb 0.7 Sn 0.3 Se 1- x Cl x ( x ≥ 0.01). We propose that breaking the crystalline mirror symmetry in TCIs could be a new research direction for exploring high-performance TE materials.

2BC Non-Structural Protein of Enterovirus A71 Interacts with SNARE Proteins to Trigger Autolysosome Formation.

PubMed

Lai, Jeffrey K F; Sam, I-Ching; Verlhac, Pauline; Baguet, Joël; Eskelinen, Eeva-Liisa; Faure, Mathias; Chan, Yoke Fun

2017-07-04

Viruses have evolved unique strategies to evade or subvert autophagy machinery. Enterovirus A71 (EV-A71) induces autophagy during infection in vitro and in vivo. In this study, we report that EV-A71 triggers autolysosome formation during infection in human rhabdomyosarcoma (RD) cells to facilitate its replication. Blocking autophagosome-lysosome fusion with chloroquine inhibited virus RNA replication, resulting in lower viral titres, viral RNA copies and viral proteins. Overexpression of the non-structural protein 2BC of EV-A71 induced autolysosome formation. Yeast 2-hybrid and co-affinity purification assays showed that 2BC physically and specifically interacted with a N -ethylmaleimide-sensitive factor attachment receptor (SNARE) protein, syntaxin-17 (STX17). Co-immunoprecipitation assay further showed that 2BC binds to SNARE proteins, STX17 and synaptosome associated protein 29 (SNAP29). Transient knockdown of STX17, SNAP29, and microtubule-associated protein 1 light chain 3B (LC3B), crucial proteins in the fusion between autophagosomes and lysosomes) as well as the lysosomal-associated membrane protein 1 (LAMP1) impaired production of infectious EV-A71 in RD cells. Collectively, these results demonstrate that the generation of autolysosomes triggered by the 2BC non-structural protein is important for EV-A71 replication, revealing a potential molecular pathway targeted by the virus to exploit autophagy. This study opens the possibility for the development of novel antivirals that specifically target 2BC to inhibit formation of autolysosomes during EV-A71 infection.

2BC Non-Structural Protein of Enterovirus A71 Interacts with SNARE Proteins to Trigger Autolysosome Formation

PubMed Central

Lai, Jeffrey K. F.; Sam, I-Ching; Verlhac, Pauline; Baguet, Joël; Faure, Mathias

2017-01-01

Viruses have evolved unique strategies to evade or subvert autophagy machinery. Enterovirus A71 (EV-A71) induces autophagy during infection in vitro and in vivo. In this study, we report that EV-A71 triggers autolysosome formation during infection in human rhabdomyosarcoma (RD) cells to facilitate its replication. Blocking autophagosome-lysosome fusion with chloroquine inhibited virus RNA replication, resulting in lower viral titres, viral RNA copies and viral proteins. Overexpression of the non-structural protein 2BC of EV-A71 induced autolysosome formation. Yeast 2-hybrid and co-affinity purification assays showed that 2BC physically and specifically interacted with a N-ethylmaleimide-sensitive factor attachment receptor (SNARE) protein, syntaxin-17 (STX17). Co-immunoprecipitation assay further showed that 2BC binds to SNARE proteins, STX17 and synaptosome associated protein 29 (SNAP29). Transient knockdown of STX17, SNAP29, and microtubule-associated protein 1 light chain 3B (LC3B), crucial proteins in the fusion between autophagosomes and lysosomes) as well as the lysosomal-associated membrane protein 1 (LAMP1) impaired production of infectious EV-A71 in RD cells. Collectively, these results demonstrate that the generation of autolysosomes triggered by the 2BC non-structural protein is important for EV-A71 replication, revealing a potential molecular pathway targeted by the virus to exploit autophagy. This study opens the possibility for the development of novel antivirals that specifically target 2BC to inhibit formation of autolysosomes during EV-A71 infection. PMID:28677644

The Quantum Dynamics of Chemical Reactions.

DTIC Science & Technology

1983-03-31

of the potential formed by taking a cut perpendicular to the minimum energy path (in Delves coordinates) V (s) = VmeP(s) + Ev(S) (5) ve sn where s is...current density and profiles of the component of jo normal to various straight-line cuts along the streamline field, for the H + H2(0) - H 2 + H...In order to visualize the nature of this topology, we display in Fig. 31 cuts of the equipotentials of V by the XZ. (y. - 0, x) and Y.Z, (’. - n/2, -x

VUV and XUV reflectance of optically coated mirrors for selection of high harmonics

DOE PAGES

Larsen, K. A.; Cryan, J. P.; Shivaram, N.; ...

2016-08-08

We report the reflectance, ~1° from normal incidence, of six different mirrors as a function of photon energy, using monochromatic vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) radiation with energies between 7.5 eV and 24.5 eV. The mirrors examined included both single and multilayer optical coatings, as well as an uncoated substrate. Furthermore, we discuss the performance of each mirror, paying particular attention to the potential application of suppression and selection of high-order harmonics of a Ti:sapphire laser.

New rare earth hafnium oxynitride perovskites with photocatalytic activity in water oxidation and reduction.

PubMed

Black, Ashley P; Suzuki, Hajime; Higashi, Masanobu; Frontera, Carlos; Ritter, Clemens; De, Chandan; Sundaresan, A; Abe, Ryu; Fuertes, Amparo

2018-02-06

RHfO 2 N perovskites with R = La, Nd and Sm show a GdFeO 3 -type structure and are semiconductors with band gaps of 3.35, 3.40 and 2.85 eV and relative dielectric constants of 30, 16 and 28 respectively. These compounds have adequate reduction and oxidation potentials to conduct the overall water splitting reaction, and the analogous perovskite LaZrO 2 N with a band gap of 2.8 eV shows photocatalytic activity under visible light irradiation for O 2 evolution.

Band Edge Positions and Their Impact on the Simulated Device Performance of ZnSnN 2-Based Solar Cells

DOE PAGES

Arca, Elisabetta; Fioretti, Angela; Lany, Stephan; ...

2017-12-07

ZnSnN 2 (ZTN) has been proposed as a new earth abundant absorber material for PV applications. While carrier concentration has been reduced to values suitable for device implementation, other properties such as ionization potential, electron affinity and work function are not known. Here, we experimentally determine the value of ionization potential (5.6 eV), electron affinity (4.1 eV) and work function (4.4 eV) for ZTN thin film samples with Zn cation composition Zn/(Zn+Sn) = 0.56 and carrier concentration n = 2x10 19cm -3. Using both experimental and theoretical results, we build a model to simulate the device performance of a ZTN/Mg:CuCrOmore » 2 solar cell, showing a potential efficiency of 23% in the limit of no defects present. We also investigate the role of band tails and recombination centers on the cell performance. In particular device simulations show that band tails are highly detrimental to the cell efficiency, and recombination centers are a major limitation if present in concentration comparable to the net carrier density. The effect of the position of the band edges of the p-type junction partner was assessed too. Through this study, we determine the major bottlenecks for the development of ZTN-based solar cell and identify avenues to mitigate them.« less

Optical absorption edge of ZnO thin films: The effect of substrate

NASA Astrophysics Data System (ADS)

Srikant, V.; Clarke, D. R.

1997-05-01

The optical absorption edge and the near-absorption edge characteristics of undoped ZnO films grown by laser ablation on various substrates have been investigated. The band edge of films on C [(0001)] and R-plane [(1102)] sapphire, 3.29 and 3.32 eV, respectively, are found to be very close to the single crystal value of ZnO (3.3 eV) with the differences being accounted for in terms of the thermal mismatch strain using the known deformation potentials of ZnO. In contrast, films grown on fused silica consistently exhibit a band edge ˜0.1 eV lower than that predicted using the known deformation potential and the thermal mismatch strains. This behavior is attributed to the small grain size (50 nm) realized in these films and the effect of electrostatic potentials that exist at the grain boundaries. Additionally, the spread in the tail (E0) of the band edge for the different films is found to be very sensitive to the defect structure in the films. For films grown on sapphire substrates, values of E0 as low as 30 meV can be achieved on annealing in air, whereas films on fused silica always show a value >100 meV. We attribute this difference to the substantially higher density of high-angle grain boundaries in the films on fused silica.

X-ray photoelectron spectrum and electronic properties of a noncentrosymmetric chalcopyrite compound HgGa(2)S(4): LDA, GGA, and EV-GGA.

PubMed

Reshak, Ali Hussain; Khenata, R; Kityk, I V; Plucinski, K J; Auluck, S

2009-04-30

An all electron full potential linearized augmented plane wave method has been applied for a theoretical study of the band structure, density of states, and electron charge density of a noncentrosymmetric chalcopyrite compound HgGa(2)S(4) using three different approximations for the exchange correlation potential. Our calculations show that the valence band maximum (VBM) and conduction band minimum (CBM) are located at Gamma resulting in a direct energy gap of about 2.0, 2.2, and 2.8 eV for local density approximation (LDA), generalized gradient approximation (GGA), and Engel-Vosko (EVGGA) compared to the experimental value of 2.84 eV. We notice that EVGGA shows excellent agreement with the experimental data. This agreement is attributed to the fact that the Engel-Vosko GGA formalism optimizes the corresponding potential for band structure calculations. We make a detailed comparison of the density of states deduced from the X-ray photoelectron spectra with our calculations. We find that there is a strong covalent bond between the Hg and S atoms and Ga and S atoms. The Hg-Hg, Ga-Ga, and S-S bonds are found to be weaker than the Hg-S and Ga-S bonds showing that a covalent bond exists between Hg and S atoms and Ga and S atoms.

Extracellular vesicles: roles in gamete maturation, fertilization and embryo implantation

PubMed Central

Machtinger, Ronit; Laurent, Louise C.; Baccarelli, Andrea A.

2016-01-01

BACKGROUND Extracellular vesicles (EVs) are membrane-bound vesicles, found in biofluids, that carry and transfer regulatory molecules, such as microRNAs (miRNAs) and proteins, and may mediate intercellular communication between cells and tissues. EVs have been isolated from a wide variety of biofluids, including plasma, urine, and, relevant to this review, seminal, follicular and uterine luminal fluid. We conducted a systematic search of the literature to review and present the currently available evidence on the possible roles of EVs in follicular growth, resumption of oocyte development and maturation (meiosis), sperm maturation, fertilization and embryo implantation. METHODS MEDLINE, Embase and Web of Science databases were searched using keywords pertaining to EVs, including ‘extracellular vesicles’, ‘microvesicles’, ‘microparticles’ and ‘exosomes’, combined with a range of terms associated with the period of development between fertilization and implantation, including ‘oocyte’, 'sperm’, 'semen’, 'fertilization’, ‘implantation’, ‘embryo’, ‘follicular fluid’, ‘epididymal fluid’ and ‘seminal fluid’. Relevant research articles published in English (both animal and human studies) were reviewed with no restrictions on publication date (i.e. from earliest database dates to July 2015). References from these articles were used to obtain additional articles. RESULTS A total of 1556 records were retrieved from the three databases. After removing duplicates and irrelevant titles, we reviewed the abstracts of 201 articles, which included 92 relevant articles. Both animal and human studies unequivocally identified various types of EVs in seminal, follicular and ULFs. Several studies provided evidence for the roles of EVs in these biofluids. In men, EVs in seminal fluid were linked with post-testicular sperm maturation, including sperm motility acquisition and reduction of oxidative stress. In women, EVs in follicular fluid were shown to contain miRNAs with potential roles in follicular growth, resumption of oocyte meiosis, steroidogenesis and prevention of polyspermy after fertilization. EVs were also detected in the media of cultured embryos, suggesting that EVs released from embryos and the uterus may mediate embryo-endometrium cross-talk during implantation. It is important to note that many of the biologically plausible functions of EVs in reproduction discussed in the current literature have not yet been substantiated by conclusive experimental evidence. CONCLUSIONS A detailed understanding of the contributions of EVs in the series of events from gametogenesis to fertilization and then on to implantation, in both normal and pathological cases, may enable the development of valuable tools to advance reproductive health. Because of the early stage of the field, it is unsurprising that the current literature includes not only growing experimental evidence, but also as-yet unproven hypotheses pertaining to the roles of EVs in key reproductive processes. In this review, we present a comprehensive survey of the rapidly expanding literature on this subject, highlighting both relevant findings and gaps in knowledge. PMID:26663221

Insights on the Synthesis, Crystal and Electronic Structures, and Optical and Thermoelectric Properties of Sr1- xSb xHfSe3 Orthorhombic Perovskite.

PubMed

Moroz, Nicholas A; Bauer, Christopher; Williams, Logan; Olvera, Alan; Casamento, Joseph; Page, Alexander A; Bailey, Trevor P; Weiland, Ashley; Stoyko, Stanislav S; Kioupakis, Emmanouil; Uher, Ctirad; Aitken, Jennifer A; Poudeu, Pierre F P

2018-06-18

Single-phase polycrystalline powders of Sr 1- x Sb x HfSe 3 ( x = 0, 0.005, 0.01), a new member of the chalcogenide perovskites, were synthesized using a combination of high temperature solid-state reaction and mechanical alloying approaches. Structural analysis using single-crystal as well as powder X-ray diffraction revealed that the synthesized materials are isostructural with SrZrSe 3 , crystallizing in the orthorhombic space group Pnma (#62) with lattice parameters a = 8.901(2) Å; b = 3.943(1) Å; c = 14.480(3) Å; and Z = 4 for the x = 0 composition. Thermal conductivity data of SrHfSe 3 revealed low values ranging from 0.9 to 1.3 W m -1 K -1 from 300 to 700 K, which is further lowered to 0.77 W m -1 K -1 by doping with 1 mol % Sb for Sr. Electronic property measurements indicate that the compound is quite insulating with an electrical conductivity of 2.9 S/cm at 873 K, which was improved to 6.7 S/cm by 0.5 mol % Sb doping. Thermopower data revealed that SrHfSe 3 is a p-type semiconductor with thermopower values reaching a maximum of 287 μV/K at 873 K for the 1.0 mol % Sb sample. The optical band gap of Sr 1- x Sb x HfSe 3 samples, as determined by density functional theory calculations and the diffuse reflectance method, is ∼1.00 eV and increases with Sb concentration to 1.15 eV. Careful analysis of the partial densities of states (PDOS) indicates that the band gap in SrHfSe 3 is essentially determined by the Se-4p and Hf-5d orbitals with little to no contribution from Sr atoms. Typically, band edges of p- and d-character are a good indication of potentially strong absorption coefficient due to the high density of states of the localized p and d orbitals. This points to potential application of SrHfSe 3 as absorbing layer in photovoltaic devices.

An ab initio study of the adsorption and dissociation of molecular oxygen on the (0 0 0 1) surface of double hexagonal close-packed americium

NASA Astrophysics Data System (ADS)

Dholabhai, Pratik P.; Atta-Fynn, Raymond; Ray, Asok K.

2008-12-01

In our continuing attempts to understand theoretically various surface properties such as corrosion and potential catalytic activity of actinide surfaces in the presence of environmental gases, we report here the first ab initio study of molecular adsorption on the double hexagonal close-packed (dhcp) americium (Am) (0 0 0 1) surface. Specifically, molecular oxygen adsorption on the (0 0 0 1) surface of dhcp Am has been studied in detail within the framework of density functional theory using a full-potential all-electron linearized augmented plane wave plus local orbitals (FP-LAPW+lo) method. Dissociative adsorption is found to be energetically more favorable compared to molecular adsorption. Chemisorption energies were optimized with respect to the distance of adsorbates from the surface for three approach positions at three adsorption sites, namely t1 (one-fold top), b2 (two-fold bridge), and h3 (three-fold hollow) sites. Chemisorption energies were computed at the scalar-relativistic-no-spin-orbit-coupling (SR-NSOC) and at the fully relativistic-with-spin-orbit-coupling (FR-SOC) levels of theory. The most stable configuration corresponds to a horizontal approach molecular dissociation with the oxygen atoms occupying neighboring h3 sites, with chemisorption energies at the NSOC and SOC theoretical levels being 9.395 and 9.886 eV, respectively. The corresponding distances of the oxygen molecule from the surface and oxygen-oxygen distance were found to be 0.953 and 3.731 Å, respectively. Overall our calculations indicate that chemisorption energies in cases with SOC are slightly more stable than those with NSOC in the 0.089-0.493 eV range. The work functions and net magnetic moments, respectively, increased and decreased in all cases compared to corresponding quantities of the bare dhcp-Am (0 0 0 1) surface. Adsorbate-substrate interactions have been analyzed in detail using partial charges inside muffin-tin spheres, difference charge density distributions, and the local density of states. The effects, if any, of chemisorption on Am5f electron localization-delocalization characteristics in the vicinity of the Fermi level are also discussed.

Local time variations of high-energy plasmaspheric ion pitch angle distributions

DOE PAGES

Sarno-Smith, Lois K.; Liemohn, Michael W.; Skoug, Ruth M.; ...

2016-07-01

Recent observations from the Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument revealed a persistent depletion in the 1–10 eV ion population in the postmidnight sector during quiet times in the 2 < L < 3 region. This study explores the source of this ion depletion by developing an algorithm to classify 26 months of pitch angle distributions measured by the HOPE instrument. We correct the HOPE low energy fluxes for spacecraft potential using measurements from the Electric Field and Waves (EFW) instrument. A high percentage of low count pitch angle distributions is found in the postmidnight sector coupledmore » with a low percentage of ion distributions peaked perpendicular to the field line. A peak in loss cone distributions in the dusk sector is also observed. Here, these results characterize the nature of the dearth of the near 90° pitch angle 1–10 eV ion population in the near-Earth postmidnight sector. This study also shows, for the first time, low-energy HOPE differential number fluxes corrected for spacecraft potential and 1–10 eV H + fluxes at different levels of geomagnetic activity.« less

Design of Metastable Tin Titanium Nitride Semiconductor Alloys

DOE PAGES

Bikowski, Andre; Siol, Sebastian; Gu, Jing; ...

2017-07-07

Here, we report on design of optoelectronic properties in previously unreported metastable tin titanium nitride alloys with spinel crystal structure. Theoretical calculations predict that Ti alloying in metastable Sn 3N 4 compound should improve hole effective mass by up to 1 order of magnitude, while other optical bandgaps remains in the 1–2 eV range up to x ~ 0.35 Ti composition. Experimental synthesis of these metastable alloys is predicted to be challenging due to high required nitrogen chemical potential (Δμ N ≥ +1.0 eV) but proven to be possible using combinatorial cosputtering from metal targets in the presence of nitrogenmore » plasma. Characterization experiments confirm that thin films of such (Sn 1–xTi x) 3N 4 alloys can be synthesized up to x = 0.45 composition, with suitable optical band gaps (1.5–2.0 eV), moderate electron densities (10 17 to 10 18 cm –3), and improved photogenerated hole transport (by 5×). Overall, this study shows that it is possible to design the metastable nitride materials with properties suitable for potential use in solar energy conversion applications.« less

AFM Study of Charge Transfer Between Metals Due to the Oxygen Redox Couple in Water

NASA Astrophysics Data System (ADS)

Trombley, Jeremy; Panthani, Tessie; Sankaran, Mohan; Angus, John; Kash, Kathleen

2010-03-01

The oxygen redox couple in an adsorbed water film can pin the Fermi level at the surfaces of diamond, GaN and ZnO.footnotetextV. Chakrapani, C. Pendyala, K. Kash, A. B. Anderson, M. K. Sunkara and J. C. Angus, J. Am. Chem. Soc. 130 (2008) 12944-12952, and ref. 6 therein. We report here preliminary observations of the same phenomenon at metal surfaces. A Pt-coated atomic force microscope (AFM) tip was used to take force-distance measurements on Au, Ag, and Pt surfaces placed in pH-controlled water. The work functions of these surfaces vary over ˜2eV and span the electrochemical potential range of the oxygen redox couple, which varies with pH according to the Nernst equation. Adjusting the pH of the water from 4 to 12 allowed us to change the redox potential energy from -5.42eV to -4.95eV, changing the surface charge and the associated screening charge and modulating the pull-off force. This work has relevance to AFM of many materials in air, and to contact electrification, mechanical friction, and nanoscale corona discharges.

Assessment of the Electrification of the Road Transport Sector on Net System Emissions

NASA Astrophysics Data System (ADS)

Miller, James

As worldwide environmental consciousness grows, electric vehicles (EVs) are becoming more common and despite the incredible potential for emissions reduction, the net emissions of the power system supply side plus the transportation system are dependent on the generation matrix. Current EV charging patterns tend to correspond directly with the peak consumption hours and have the potential to increase demand sharply allowing for only a small penetration of Electric Vehicles. Using the National Household Travel Survey (NHTS) data a model is created for vehicle travel patterns using trip chaining. Charging schemes are modeled to include uncontrolled residential, uncontrolled residential/industrial charging, optimized charging and optimized charging with vehicle to grid discharging. A charging profile is then determined based upon the assumption that electric vehicles would directly replace a percentage of standard petroleum-fueled vehicles in a known system. Using the generation profile for the specified region, a unit commitment model is created to establish not only the generation dispatch, but also the net CO2 profile for variable EV penetrations and charging profiles. This model is then used to assess the impact of the electrification of the road transport sector on the system net emissions.

Atomistic modeling trap-assisted tunneling in hole tunnel field effect transistors

NASA Astrophysics Data System (ADS)

Long, Pengyu; Huang, Jun Z.; Povolotskyi, Michael; Sarangapani, Prasad; Valencia-Zapata, Gustavo A.; Kubis, Tillmann; Rodwell, Mark J. W.; Klimeck, Gerhard

2018-05-01

Tunnel Field Effect Transistors (FETs) have the potential to achieve steep Subthreshold Swing (S.S.) below 60 mV/dec, but their S.S. could be limited by trap-assisted tunneling (TAT) due to interface traps. In this paper, the effect of trap energy and location on OFF-current (IOFF) of tunnel FETs is evaluated systematically using an atomistic trap level representation in a full quantum transport simulation. Trap energy levels close to band edges cause the highest leakage. Wave function penetration into the surrounding oxide increases the TAT current. To estimate the effects of multiple traps, we assume that the traps themselves do not interact with each other and as a whole do not modify the electrostatic potential dramatically. Within that model limitation, this numerical metrology study points to the critical importance of TAT in the IOFF in tunnel FETs. The model shows that for Dit higher than 1012/(cm2 eV) IO F F is critically increased with a degraded IO N/IO F F ratio of the tunnel FET. In order to have an IO N/IO F F ratio higher than 104, the acceptable Dit near Ev should be controlled to no larger than 1012/(cm2 eV) .

Deposition of nanocomposite Cu-TiO2 using heterogeneous colliding plasmas

NASA Astrophysics Data System (ADS)

Pandey, Pramod K.; Thareja, Raj K.; Singh, Ravi Pratap; Costello, John T.

2018-03-01

The formation of CuTiO2 nanocomposites has been observed in an experiment in which laser plasma plumes of Cu and Ti collide and stagnate in an oxygen atmosphere. The inherent advantage of this technique lies in its simplicity and flexibility where laser, target composition and geometry along with ambient atmosphere are all controllable parameters through which the stoichiometry of the deposited nanocomposites may be selected. The experiment has been performed at three oxygen ambient pressures 10-4, 10-2, 100 mbar and we observe its effect on stoichiometry, and morphology of the deposited nanocomposites. Here, we show how the stoichiometry of deposited nanocomposites can be readily controlled by changing just one parameter, namely the ambient oxygen pressure. The different peaks of photoluminescence spectra λ =390{ nm}( {E=3.18{ eV}} ) corresponding to the anatase phase of TiO2, along with the peaks at λ = 483 nm ( E = 2.56 eV) and 582 nm ( E = 2.13 eV) of deposited nanocomposites, shows the doping/blending effect on the band gaps which may potentially be of value in solar cell technology. The technique can, in principle, be extended to include nanocomposites of other materials making it potentially more widely applicable.

Temperature-Dependent, Linearly Interpolable, Tabulated Cross Section Library Based on ENDF/B-VI, Release 8.

DOE Office of Scientific and Technical Information (OSTI.GOV)

CULLEN, D. E.

2005-02-21

Version 00 As distributed, the original evaluated data include cross sections represented in the form of a combination of resonance parameters and/or tabulated energy dependent cross sections, nominally at 0 Kelvin temperature. For use in applications this library has been processed into the form of temperature dependent cross sections at eight neutron reactor like temperatures, between 0 and 2100 Kelvin, in steps of 300 Kelvin. It has also been processed to five astrophysics like temperatures, 1, 10, 100 eV, 1 and 10 keV. For reference purposes, 300 Kelvin is approximately 1/40 eV, so that 1 eV is approximately 12,000 Kelvin.more » At each temperature the cross sections are tabulated and linearly interpolable in energy. POINT2004 contains all of the evaluations in the ENDF/B-VI general purpose library, which contains evaluations for 328 materials (isotopes or naturally occurring elemental mixtures of isotopes). No special purpose ENDF/B-VI libraries, such as fission products, thermal scattering, or photon interaction data are included. The majority of these evaluations are complete, in the sense that they include all cross sections over the energy range 10-5 eV to at least 20 MeV. However, the following are only partial evaluations that either contain only single reactions and no total cross section (Mg24, K41, Ti46, Ti47, Ti48, Ti50 and Ni59), or do not include energy dependent cross sections above the resonance region (Ar40, Mo92, Mo98, Mo100, In115, Sn120, Sn122 and Sn124). The CCC-638/TART20002 code package is recommended for use with these data. Codes within TART can be used to display these data or to run calculations using these data.« less

Portal Hypertension in Patients with Liver Cirrhosis: Diagnostic Accuracy of Spleen Stiffness.

PubMed

Takuma, Yoshitaka; Nouso, Kazuhiro; Morimoto, Youichi; Tomokuni, Junko; Sahara, Akiko; Takabatake, Hiroyuki; Matsueda, Kazuhiro; Yamamoto, Hiroshi

2016-05-01

To evaluate the accuracy of spleen stiffness (SS) and liver stiffness (LS) measured by using acoustic radiation force impulse imaging in the diagnosis of portal hypertension in patients with liver cirrhosis, with the hepatic venous pressure gradient (HVPG) as a reference standard. Institutional review board approval and informed consent were obtained for this prospective single-center study. From February 2012 to August 2013, 60 patients with liver cirrhosis (mean age, 70.8 years; age range, 34-88 years; 34 men, 26 women) with HVPG, LS, and SS measurements and gastrointestinal endoscopy and laboratory data were included if they met the following criteria: no recent episodes of gastrointestinal bleeding, no history of splenectomy, no history of partial splenic embolization, no history of β-blocker therapy, and absence of portal thrombosis. The efficacy of the parameters for the evaluation of portal hypertension was analyzed by using the Spearman rank-order correlation coefficient and receiver operating characteristic (ROC) curve analysis. The correlation coefficient between SS and HVPG (r = 0.876) was significantly better than that between LS and HVPG (r = 0.609, P < .0001). The areas under the ROC curve of SS for the identification of clinically important portal hypertension (HVPG ≥ 10 mm Hg), severe portal hypertension (HVPG ≥ 12 mm Hg), esophageal varices (EVs), and high-risk EVs were significantly higher (0.943, 0.963, 0.937, and 0.955, respectively) than those of LS, spleen diameter, platelet count, and platelet count to spleen diameter ratio (P < .05 for all). SS could be used to accurately rule out the presence of clinically important portal hypertension, severe portal hypertension, EVs, and high-risk EVs (negative likelihood ratios, 0.051, 0.056, 0.054, and 0.074, respectively). SS is reliable and has better diagnostic performance than LS for identifying portal hypertension in liver cirrhosis. (©) RSNA, 2015 Online supplemental material is available for this article.

Current status of the Essential Variables as an instrument to assess the Earth Observation Networks in Europe

NASA Astrophysics Data System (ADS)

Blonda, Palma; Maso, Joan; Bombelli, Antonio; Plag, Hans Peter; McCallum, Ian; Serral, Ivette; Nativi, Stefano Stefano

2016-04-01

ConnectinGEO (Coordinating an Observation Network of Networks EnCompassing saTellite and IN-situ to fill the Gaps in European Observations" is an H2020 Coordination and Support Action with the primary goal of linking existing Earth Observation networks with science and technology (S&T) communities, the industry sector, the Group on Earth Observations (GEO), and Copernicus. The project will end in February 2017. Essential Variables (EVs) are defined by ConnectinGEO as "a minimal set of variables that determine the system's state and developments, are crucial for predicting system developments, and allow us to define metrics that measure the trajectory of the system". . Specific application-dependent characteristics, such as spatial and temporal resolution of observations and data quality thresholds, are not generally included in the EV definition. This definition and the present status of EV developments in different societal benefit areas was elaborated at the ConnectinGEO workshop "Towards a sustainability process for GEOSS Essential Variables (EVs)," which was held in Bari on June 11-12, 2015 (http://www.gstss.org/2015_Bari/). Presentations and reports contributed by a wide range of communities provided important inputs from different sectors for assessing the status of the EV development. In most thematic areas, the development of sets of EVs is a community process leading to an agreement on what is essential for the goals of the community. While there are many differences across the communities in the details of the criteria, methodologies and processes used to develop sets of EVs, there is also a considerable common core across the communities, particularly those with a more advanced discussion. In particular, there is some level of overlap in different topics (e.g., Climate and Water), and there is a potential to develop an integrated set of EVs common to several thematic areas as well as specific ones that satisfy only one community. The thematic areas with a more mature development of EV lists are Climate (ECV), Ocean (EOV) and Biodiversity (EBV). Water is also developing a set of EVs in GEOSS. Agriculture is working with a common set of variables that can be considered essential to them such as Crop Area, Crop Type, Crop Condition, etc.. More work is required for an agreement on other sets of EVs for Disasters, Health and Ecosystems. Being cross-domain topics, these areas can make use of existing sets of EVs (such as ECVs, EOVs and EBVs) complemented by socioeconomic variables that can help to characterize services (e.g., ecosystem services) to human societies. Renewable energy also makes use of the ECVs but there is a need for additional ones: solar surface irradiance and wind at different heights are good candidates to explore. ConnectinGEO will link with Climate, Ocean and Biodiversity communities and support Water, Agriculture, Renewable Energy, Health, Disasters and Ecosystems to make progress in the EV development by stimulating the debate in their respective international forums (mainly in GEOSS). The final objective is to foster EV extraction from the integrated use of in-situ and satellite Earth Observation data.

Ground and excited state dissociation dynamics of ionized 1,1-difluoroethene.

PubMed

Gridelet, E; Dehareng, D; Locht, R; Lorquet, A J; Lorquet, J C; Leyh, B

2005-09-22

The kinetic energy release distributions (KERDs) for the fluorine atom loss from the 1,1-difluoroethene cation have been recorded with two spectrometers in two different energy ranges. A first experiment uses dissociative photoionization with the He(I) and Ne(I) resonance lines, providing the ions with a broad internal energy range, up to 7 eV above the dissociation threshold. The second experiment samples the metastable range, and the average ion internal energy is limited to about 0.2 eV above the threshold. In both energy domains, KERDs are found to be bimodal. Each component has been analyzed by the maximum entropy method. The narrow, low kinetic energy components display for both experiments the characteristics of a statistical, simple bond cleavage reaction: constraint equal to the square root of the fragment kinetic energy and ergodicity index higher than 90%. Furthermore, this component is satisfactorily accounted for in the metastable time scale by the orbiting transition state theory. Potential energy surfaces corresponding to the five lowest electronic states of the dissociating 1,1-C2H2F2+ ion have been investigated by ab initio calculations at various levels. The equilibrium geometry of these states, their dissociation energies, and their vibrational wavenumbers have been calculated, and a few conical intersections between these surfaces have been identified. It comes out that the ionic ground state X2B1 is adiabatically correlated with the lowest dissociation asymptote. Its potential energy curve increases in a monotonic way along the reaction coordinate, giving rise to the narrow KERD component. Two states embedded in the third photoelectron band (B2A1 at 15.95 eV and C2B2 at 16.17 eV) also correlate with the lowest asymptote at 14.24 eV. We suggest that their repulsive behavior along the reaction coordinate be responsible for the KERD high kinetic energy contribution.

Design and analysis of aluminum/air battery system for electric vehicles

NASA Astrophysics Data System (ADS)

Yang, Shaohua; Knickle, Harold

Aluminum (Al)/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars. From our design analysis, it can be seen that the cost of aluminum as an anode can be as low as US 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected) comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

Protein and Molecular Characterization of a Clinically Compliant Amniotic Fluid Stem Cell-Derived Extracellular Vesicle Fraction Capable of Accelerating Muscle Regeneration Through Enhancement of Angiogenesis.

PubMed

Mellows, Ben; Mitchell, Robert; Antonioli, Manuela; Kretz, Oliver; Chambers, David; Zeuner, Marie-Theres; Denecke, Bernd; Musante, Luca; Ramachandra, Durrgah L; Debacq-Chainiaux, Florence; Holthofer, Harry; Joch, Barbara; Ray, Steve; Widera, Darius; David, Anna L; Huber, Tobias B; Dengjel, Joern; De Coppi, Paolo; Patel, Ketan

2017-09-15

The secretome of human amniotic fluid stem cells (AFSCs) has great potential as a therapeutic agent in regenerative medicine. However, it must be produced in a clinically compliant manner before it can be used in humans. In this study, we developed a means of producing a biologically active secretome from AFSCs that is free of all exogenous molecules. We demonstrate that the full secretome is capable of promoting stem cell proliferation, migration, and protection of cells against senescence. Furthermore, it has significant anti-inflammatory properties. Most importantly, we show that it promotes tissue regeneration in a model of muscle damage. We then demonstrate that the secretome contains extracellular vesicles (EVs) that harbor much, but not all, of the biological activity of the whole secretome. Proteomic characterization of the EV and free secretome fraction shows the presence of numerous molecules specific to each fraction that could be key regulators of tissue regeneration. Intriguingly, we show that the EVs only contain miRNA and not mRNA. This suggests that tissue regeneration in the host is mediated by the action of EVs modifying existing, rather than imposing new, signaling pathways. The EVs harbor significant anti-inflammatory activity as well as promote angiogenesis, the latter may be the mechanistic explanation for their ability to promote muscle regeneration after cardiotoxin injury.

Electron affinity and surface states of GaN m -plane facets: Implication for electronic self-passivation

NASA Astrophysics Data System (ADS)

Portz, V.; Schnedler, M.; Eisele, H.; Dunin-Borkowski, R. E.; Ebert, Ph.

2018-03-01

The electron affinity and surface states are of utmost importance for designing the potential landscape within (heterojunction) nanowires and hence for tuning conductivity and carrier lifetimes. Therefore, we determined for stoichiometric nonpolar GaN (10 1 ¯0 ) m -plane facets, i.e., the dominating sidewalls of GaN nanowires, the electron affinity to 4.06 ±0.07 eV and the energy of the empty Ga-derived surface state in the band gap to 0.99 ±0.08 eV below the conduction band minimum using scanning tunneling spectroscopy. These values imply that the potential landscape within GaN nanowires is defined by a surface state-induced Fermi-level pinning, creating an upward band bending at the sidewall facets, which provides an electronic passivation.

Impact of Fast Charging on Life of EV Batteries; NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neubauer, Jeremy; Wood, Eric; Burton, Evan

Installation of fast charging infrastructure is considered by many as one of potential solutions to increase the utility and range of electric vehicles (EVs). This is expected to reduce the range anxiety of drivers of EVs and thus increase their market penetration. Level 1 and 2 charging in homes and workplaces is expected to contribute to the majority of miles driven by EVs. However, a small percentage of urban driving and most of inter-city driving could be only achieved by a fast-charging network. DC fast charging at 50 kW, 100 kW, 120 kW compared to level 1 (3.3 kW) andmore » level 2 (6.6 kW) results in high-current charging that can adversely impact the life of the battery. In the last couple of years, we have investigated the impact of higher current rates in batteries and potential of higher temperatures and thus lower service life. Using mathematical models, we investigated the temperature increase of batteries due to higher heat generation during fast charge and have found that this could lead to higher temperatures. We compared our models with data from other national laboratories both for fine-tuning and calibration. We found that the incremental temperature rise of batteries during 1C to 3C fast charging may reduce the practical life of the batteries by less than 10% over 10 to 15 years of vehicle ownership. We also found that thermal management of batteries is needed for fast charging to prevent high temperature excursions leading to unsafe conditions.« less

Stress distribution and mechanical properties of free and assembled Ni3Al nanoclusters

NASA Astrophysics Data System (ADS)

Zhurkin, E. E.; Hautier, G.; Hou, M.

2006-03-01

Classical molecular dynamics with a semiempirical N -body potential is used to study the distribution of local stress in bimetallic Ni3Al nanoparticles and in cluster-assembled materials. The materials considered are synthesized with these particles by low-energy deposition at 0.5eV per atom and by compaction with an external pressure of 2GPa , thus featuring different nanostructures. Both are nanoporous, the lowest density being obtained by deposition. Their mechanical response to a uniaxial external load is then studied and deformation mechanisms are identified and are found to be similar in both nanostructures. In the core of isolated clusters, the partial pressures on the nickel and aluminium subsystems are found to differ by several GPa and, as a balance to surface tension, the hydrostatic core pressure is positive and depends on the cluster size. The surface stress is tensile and, because of structural disorder, the partial pressures distributions on Ni and Al at the surface are scattered. When nanostructured systems are formed, strong and highly inhomogeneous shear stress appears, the cluster cores may become tensile, and the interfacial areas remain mainly tensile as well. The partial pressure difference between Ni and Al is somewhat reduced. It is shown that the effect of temperature is to reduce this difference still further and to homogenize the spatial stress distribution. When subjected to a uniaxial stress, both materials display an elastic and a plastic regime. The elastic limit is the lowest for the most porous material and decreases with increasing temperature. Plastic deformation is dominated by both grain boundary sliding and by the enlargement of the open volumes, without evidence for the nucleation of cracks. These open volumes are found to facilitate dislocation activity which is evidenced in grains with sizes as small as two nanometers. This dislocation activity is found to result in the production of stacking faults as well as to the recovery of defects induced by the deposition or by the compaction.

Influence of nuclear exchange on nonadiabatic electron processes in H(+)+H2 collisions.

PubMed

Errea, L F; Illescas, Clara; Macías, A; Méndez, L; Pons, B; Rabadán, I; Riera, A

2010-12-28

H(+)+H(2) collisions are studied by means of a semiclassical approach that explicitly accounts for nuclear rearrangement channels in nonadiabatic electron processes. A set of classical trajectories is used to describe the nuclear motion, while the electronic degrees of freedom are treated quantum mechanically in terms of a three-state expansion of the collision wavefunction. We describe electron capture and vibrational excitation, which can also involve nuclear exchange and dissociation, in the E = 2-1000 eV impact energy range. We compare dynamical results obtained with two parametrizations of the potential energy surface of H(3)(+) ground electronic state. Total cross sections for E > 10 eV agree with previous results using a vibronic close-coupling expansion, and with experimental data for E < 10 eV. Additionally, some prototypical features of both nuclear and electron dynamics at low E are discussed.

Al/Ti/Al phonon-mediated KIDs for UV–vis light detection over large areas

NASA Astrophysics Data System (ADS)

Cardani, L.; Casali, N.; Cruciani, A.; le Sueur, H.; Martinez, M.; Bellini, F.; Calvo, M.; Castellano, M. G.; Colantoni, I.; Cosmelli, C.; D’Addabbo, A.; Di Domizio, S.; Goupy, J.; Minutolo, L.; Monfardini, A.; Vignati, M.

2018-07-01

The development of wide-area cryogenic light detectors with baseline energy resolution lower than 20 eV RMS is essential for next generation bolometric experiments searching for rare interactions. Indeed the simultaneous readout of the light and heat signals will enable background suppression through particle identification. Because of their excellent intrinsic energy resolution, as well as their well-established reproducibility, kinetic inductance detectors (KIDs) are good candidates for the development of next generation light detectors. The CALDER project is investigating the potential of phonon-mediated KIDs. The first phase of the project allowed to reach a baseline resolution of 80 eV using a single KID made of aluminum on a 2 × 2 cm2 silicon substrate acting as photon absorber. In this paper we present a new prototype detector implementing a trilayer aluminum–titanium–aluminum KID. Taking advantage of superconducting proximity effect the baseline resolution improves down to 26 eV.

Complete chemical transformation of a molecular film by subexcitation electrons (<3 eV).

PubMed

Balog, Richard; Illenberger, Eugen

2003-11-21

The potential of slow electrons to act as a soft tool to control a chemical reaction in the condensed phase is demonstrated. By setting the energy of a well defined electron beam to values below 3 eV, the surface of a thin film of 1,2-C(2)F(4)C(l2) molecules can completely be transformed into molecular chlorine (and by-products, possibly perfluorinated polymers). At higher energies (>6 eV) some equilibrium state between product and educt composition can be achieved, however, accompanied by a gradual overall degradation of the film. The effect of complete transformation is based on both the selectivity and particular energy dependence of the initial step of the reaction which is dissociative electron attachment to C(2)F(4)C(l2), but also the fact that the initial molecule is efficiently decomposed by subexcitation electrons while the product C(l2) is virtually unaffected.

DINS measurements on VESUVIO in the Resonance Detector configuration: proton mean kinetic energy in water

NASA Astrophysics Data System (ADS)

Pietropaolo, Antonino; Andreani, Carla; Filabozzi, Alessandra; Senesi, Roberto; Gorini, Giuseppe; Perelli-Cippo, Enrico; Tardocchi, Marco; Rhodes, Nigel J.; Schooneveld, Erik M.

2006-04-01

Deep Inelastic Neutron Scattering (DINS) measurements have been performed on a liquid water sample at two different temperatures and pressures. The experiments were carried out using the VESUVIO spectrometer at the ISIS spallation neutron source. This experiment represents the first DINS measurement from water using the Resonance Detector configuration, employing yttrium-aluminum-perovskite scintillator and a 238U analyzer foil. The maximum energy of the scattered neutrons was about 70 eV, allowing to access an extended kinematic space with energy and wave vector transfers at the proton recoil peak in the range 1 eV <= hbarω <= 20 eV and 25 Å-1 <= q <= 90 Å-1, respectively. Comparison with DINS measurements on water performed in the standard Resonance Filter configuration indicates the potential advantages offered by the use of Resonance Detector approach for DINS measurements at forward scattering angles.

Spectroscopic analysis of transition state energy levels - Bending-rotational spectrum and lifetime analysis of H3 quasibound states

NASA Technical Reports Server (NTRS)

Zhao, Meishan; Mladenovic, Mirjana; Truhlar, Donald G.; Schwenke, David W.; Sharafeddin, Omar

1989-01-01

Converged quantum mechanical calculations of scattering matrices and transition probabilities are reported for the reaction of H with H2 with total angular momentum 0, 1, and 4 as functions of total energy in the range 0.85-1.15 eV on an accurate potential energy surface. The resonance structure is illustrated with Argand diagrams. State-to-state reactive collision delay times and lifetimes are presented. For J = 0, 1, and 4, the lowest-energy H3 resonance is at total energies of 0.983, 0.985, and 1.01 eV, respectively, with lifetimes of about 16-17 fs. For J = 1 and 4 there is a higher-energy resonance at 1.10-1.11 eV. For J = 1 the lifetime is about 4 fs and for J = 4 it is about 1 fs.

Analytical Pipeline for Discovery and Verification of Glycoproteins from Plasma-Derived Extracellular Vesicles as Breast Cancer Biomarkers.

PubMed

Chen, I-Hsuan; Aguilar, Hillary Andaluz; Paez Paez, J Sebastian; Wu, Xiaofeng; Pan, Li; Wendt, Michael K; Iliuk, Anton B; Zhang, Ying; Tao, W Andy

2018-05-15

Glycoproteins comprise more than half of current FDA-approved protein cancer markers, but the development of new glycoproteins as disease biomarkers has been stagnant. Here we present a pipeline to develop glycoproteins from extracellular vesicles (EVs) through integrating quantitative glycoproteomics with a novel reverse phase glycoprotein array and then apply it to identify novel biomarkers for breast cancer. EV glycoproteomics show promise in circumventing the problems plaguing current serum/plasma glycoproteomics and allowed us to identify hundreds of glycoproteins that have not been identified in blood. We identified 1,453 unique glycopeptides representing 556 glycoproteins in EVs, among which 20 were verified significantly higher in individual breast cancer patients. We further applied a novel glyco-specific reverse phase protein array to quantify a subset of the candidates. Together, this study demonstrates the great potential of this integrated pipeline for biomarker discovery.

Ab-initio calculations of electronic, transport, and structural properties of boron phosphide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ejembi, J. I.; Nwigboji, I. H.; Franklin, L.

2014-09-14

We present results from ab-initio, self-consistent density functional theory calculations of electronic and related properties of zinc blende boron phosphide (zb-BP). We employed a local density approximation potential and implemented the linear combination of atomic orbitals formalism. This technique follows the Bagayoko, Zhao, and Williams method, as enhanced by the work of Ekuma and Franklin. The results include electronic energy bands, densities of states, and effective masses. The calculated band gap of 2.02 eV, for the room temperature lattice constant of a=4.5383 Å, is in excellent agreement with the experimental value of 2.02±0.05 eV. Our result for the bulk modulus,more » 155.7 GPa, agrees with experiment (152–155 GPa). Our predictions for the equilibrium lattice constant and the corresponding band gap, for very low temperatures, are 4.5269 Å and 2.01 eV, respectively.« less

A Complete Set of Radiative and Auger Rates for K-vacancy States in Fe XVIII-Fe-XXV

NASA Technical Reports Server (NTRS)

Palmeri, P.; Mendoza, C.; Kallman, T. R.; Bautista, M. A.

2003-01-01

A complete set of level energies, wavelengths, A-values, and total and partial Auger rates have been computed for transitions involving the K-vacancy states within the n = 2 complex of Fe XVIII-Fe XXV. Three different standard numerical packages are used for this purpose, namel y AUTOSTRUCTURE, the Breit-Pauli R-matrix suite (BPRM) and HFR, which allow reliable estimates of the physical effects involved and of the accuracy of the resulting data sets. The Breit interaction is taken i nto account because its contributions to the small A-values and partial Auger rates cannot be neglected with increasing electron occupancy. Semiempirical adjustments can also lead to large differences in both the radiative and Auger decay data of strongly mixed levels. Several experimental level energies and wavelengths are questioned, and significant discrepancies are found with previously computed decay rates th at are attributed to numerical problems. The statistical accuracy of the present level energies and wavelengths is ranked at +/-3 eV and +/ -2 mA, respectively, and that for A-values and partial Auger rates greater than lO(exp 13)/s at better than 20%.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merkulov, O.V., E-mail: merkulov@ihim.uran.ru; Samigullin, R.R.; Markov, A.A.

The electrical conductivity of SrFe{sub 1–x}Sn{sub x}O{sub 3–δ} (x=0.05, 0.10, 017) was measured by a four-probe dc technique in the partial oxygen pressure range of 10{sup –18}–0.5 atm at temperatures between 800 °Ð ÐŽ and 950 °Ð ÐŽ. The oxygen content in these oxides was measured under the same ambient conditions by means of coulometric titration. The thermodynamic analysis of oxygen nonstoichiometry data was carried out to determine the equilibrium constants for defect-formation reactions and to calculate the concentrations of ion and electron charge carriers. The partial contributions of oxygen ions, electrons and holes to charge transport were assessed, and the mobilitymore » of respective carriers was evaluated by an integral examination of the electrical conductivity and oxygen nonstoichiometry data. It has been found that the mobility of holes in SrFe{sub 1−x}Sn{sub x}O{sub 3−δ} varies in the range of ~0.005–0.04 cm{sup 2} V{sup −1} s{sup −1}, linearly increasing with the oxygen content and decreasing with increased tin concentration. The mobility of electron carriers was shown to be independent of the oxygen content. The average migration energy of an electron was estimated to be ~0.45 eV, with that of a hole being ~0.3 eV. - Highlights: • The conductivity and oxygen nonstoichiometry in SrFe{sub 1−x}Sn{sub x}O{sub 3−δ} were measured. • Tin substitution was found to affect insignificantly defect formation reactions. • The hole mobility was found to increase linearly with the oxygen content. • The hole mobility was found to be much higher than the electron mobility.« less

Water Splitting with Series-Connected Polymer Solar Cells.

PubMed

Esiner, Serkan; van Eersel, Harm; van Pruissen, Gijs W P; Turbiez, Mathieu; Wienk, Martijn M; Janssen, René A J

2016-10-12

We investigate light-driven electrochemical water splitting with series-connected polymer solar cells using a combined experimental and modeling approach. The expected maximum solar-to-hydrogen conversion efficiency (η STH ) for light-driven water splitting is modeled for two, three, and four series-connected polymer solar cells. In the modeling, we assume an electrochemical water splitting potential of 1.50 V and a polymer solar cell for which the external quantum efficiency and fill factor are both 0.65. The minimum photon energy loss (E loss ), defined as the energy difference between the optical band gap (E g ) and the open-circuit voltage (V oc ), is set to 0.8 eV, which we consider a realistic value for polymer solar cells. Within these approximations, two series-connected single junction cells with E g = 1.73 eV or three series-connected cells with E g = 1.44 eV are both expected to give an η STH of 6.9%. For four series-connected cells, the maximum η STH is slightly less at 6.2% at an optimal E g = 1.33 eV. Water splitting was performed with series-connected polymer solar cells using polymers with different band gaps. PTPTIBDT-OD (E g = 1.89 eV), PTB7-Th (E g = 1.56 eV), and PDPP5T-2 (E g = 1.44 eV) were blended with [70]PCBM as absorber layer for two, three, and four series-connected configurations, respectively, and provide η STH values of 4.1, 6.1, and 4.9% when using a retroreflective foil on top of the cell to enhance light absorption. The reasons for deviations with experiments are analyzed and found to be due to differences in E g and E loss . Light-driven electrochemical water splitting was also modeled for multijunction polymer solar cells with vertically stacked photoactive layers. Under identical assumptions, an η STH of 10.0% is predicted for multijunction cells.

In the driver`s seat

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-03-01

At the 1996 North American Electric Vehicle Infrastructure (NAEVI) Conference in San Diego, there were plenty of electric vehicles, plenty of people who could sell you electric vehicles, and plenty of people who had plans to roll out entire lines of electric vehicles. Several companies offered EV retrofits and have been offering them for years. Some companies would put electronics in a {open_quotes}glider{close_quotes} (the empty chassis and body of another manufacturer`s car). Some bigger companies had EVs that were {open_quotes}ground-up{close_quotes} vehicles--original EVs built without using another manufacturer`s glider. The biggest companies--Ford, Chrysler, Honda, Toyota, and Nissan--all had EVs that weremore » well on their way to moving past the prototype stage and into real line production for the 1998 model year. But only one car targeted to the general population was actually available to retail customers from a major automaker; only one car had entered the market as a true production vehicle. General Motors` EV1, available through 26 Saturn Corporation retail facilities in Los Angeles, San Diego, Phoenix, and Tucson. The EV1 goes 0 to 60 miles per hour in less than nine seconds. It has a range potential of 70 miles (in the city) to 90 miles (on the highway). Among other things, it has air-conditioning, a CD player, power windows and doors, cruise control, airbags, and intermittent wipers. You can choose from red, dark green, and blue-silver. Plus, it has keyless entry and ignition (in EV terms, {open_quotes}vehicle activation{close_quotes}) and a tire-pressure monitoring system. And it`s all electric. It has a portable 110-volt charger hook-up in the trunk when you don`t have access to a stationary 220-volt MagneCharge charger. The convenience charger takes about 15 hours for a full charge; the stationary one, 3 to 4 hours.« less

Cultured human amniocytes express hTERT, which is distributed between nucleus and cytoplasm and is secreted in extracellular vesicles.

PubMed

Radeghieri, Annalisa; Savio, Giulia; Zendrini, Andrea; Di Noto, Giuseppe; Salvi, Alessandro; Bergese, Paolo; Piovani, Giovanna

2017-01-29

An increasing number of studies on stem cells suggests that the therapeutic effect they exert is primarily mediated by a paracrine regulation through extracellular vesicles (EVs) giving solid grounds for stem cell EVs to be exploited as agents for treating diseases or for restoring damaged tissues and organs. Due to their capacity to differentiate in all embryonic germ layers, amniotic fluid stem cells (AFCs), represent a highly promising cell type for tissue regeneration, which however is still poorly studied and in turn underutilized. In view of this, we conducted a first investigation on the expression of human hTERT gene - known to be among the key triggers of organ regeneration - in AFCs and in the EVs they secrete. Isolated AFCs were evaluated by RT-qPCR for hTERT expression. The clones expressing the highest levels of transcript, were analyzed by Immunofluorescence imaging and Nuclear/cytoplasmic fractionation in order to evaluate hTERT subcellular localization. We then separated EVs from FBS depleted culture medium by serial (ultra) centrifugations steps and characterized them using Western blotting, Atomic force Microscopy and Nanoplasmonic assay. We first demonstrated that primary cultures of AFCs express the gene hTERT at different levels. Then we evidenced that in AFCs with the higher transcript levels, the hTERT protein is present in the nuclear and cytoplasmic compartment. Finally, we found that cytosolic hTERT is embodied in the EVs that AFCs secrete in the extracellular milieu. Our study demonstrates for the first time the expression of the full protein hTERT by AFCs and its release outside the cell mediated by EVs, indicating a new extra telomeric role for this protein. This finding represents an initial but crucial evidence for considering AFCs derived EVs as new potential sources for tissue regeneration. Copyright © 2016 Elsevier Inc. All rights reserved.