6,470 research outputs found
Evaluation of the silver species nature in Ag-ITQ2 zeolites by the CO oxidation reaction
The authors thank the Spanish Ministry of Economy and Competitiveness through RTI2018-101784-B-I00 (MINECO/FEDER) and SEV-2016-0683 projects for the financial support. We gratefully acknowledge ALBA synchrotron for allocating beamtime (proposal 2015091414) and the CLAESS beamline staff for their help and technical support during our experiment. CG and NB thank the TUW Innovative Project GIP165CDGC. CG, SP, VT, NB and GR are thankful for financial support from the Austrian Science Fund (FWF) through projects DK+ Solids4Fun (W1243) and ComCat (I 1041-N28). I. Lopez Hernandez is grateful to Generalitat Valenciana and European Social Fund for the pre doctoral grant ACIF2017.López-Hernández, I.; García Yago, CI.; Truttmann, V.; Pollit, S.; Barrabés, N.; Rupprechter, G.; Rey Garcia, F.... (2020). Evaluation of the silver species nature in Ag-ITQ2 zeolites by the CO oxidation reaction. Catalysis Today. 345:22-26. https://doi.org/10.1016/j.cattod.2019.12.001S2226345Serhan, N., Tsolakis, A., Wahbi, A., Martos, F. J., & Golunski, S. (2019). Modifying catalytically the soot morphology and nanostructure in diesel exhaust: Influence of silver De-NOx catalyst (Ag/Al2O3). Applied Catalysis B: Environmental, 241, 471-482. doi:10.1016/j.apcatb.2018.09.068Góra-Marek, K., Tarach, K. A., Piwowarska, Z., Łaniecki, M., & Chmielarz, L. (2016). Ag-loaded zeolites Y and USY as catalysts for selective ammonia oxidation. Catalysis Science & Technology, 6(6), 1651-1660. doi:10.1039/c5cy01446hHu, X., Bai, J., Hong, H., & Li, C. (2016). Supercritical carbon dioxide anchored highly dispersed silver nanoparticles on 4A-zeolite and selective oxidation of styrene performance. CrystEngComm, 18(14), 2469-2476. doi:10.1039/c5ce02435hCerrillo, J. L., Palomares, A. E., Rey, F., Valencia, S., Pérez-Gago, M. B., Villamón, D., & Palou, L. (2018). Functional Ag-Exchanged Zeolites as Biocide Agents. 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Chemical Reviews, 118(10), 4981-5079. doi:10.1021/acs.chemrev.7b00776Zhao, J., & Jin, R. (2018). Heterogeneous catalysis by gold and gold-based bimetal nanoclusters. Nano Today, 18, 86-102. doi:10.1016/j.nantod.2017.12.009Zhang, B., Kaziz, S., Li, H., Hevia, M. G., Wodka, D., Mazet, C., … Barrabés, N. (2015). Modulation of Active Sites in Supported Au38(SC2H4Ph)24 Cluster Catalysts: Effect of Atmosphere and Support Material. The Journal of Physical Chemistry C, 119(20), 11193-11199. doi:10.1021/jp512022vZhang, B., Sels, A., Salassa, G., Pollitt, S., Truttmann, V., Rameshan, C., … Barrabés, N. (2018). Ligand Migration from Cluster to Support: A Crucial Factor for Catalysis by Thiolate‐protected Gold Clusters. ChemCatChem, 10(23), 5372-5376. doi:10.1002/cctc.201801474Natarajan, G., Mathew, A., Negishi, Y., Whetten, R. L., & Pradeep, T. (2015). A Unified Framework for Understanding the Structure and Modifications of Atomically Precise Monolayer Protected Gold Clusters. The Journal of Physical Chemistry C, 119(49), 27768-27785. doi:10.1021/acs.jpcc.5b08193Tsukuda, T., & Häkkinen, H. (2015). Introduction. Protected Metal Clusters - From Fundamentals to Applications, 1-7. doi:10.1016/b978-0-08-100086-1.00001-4Zhang, X., Qu, Z., Li, X., Wen, M., Quan, X., Ma, D., & Wu, J. (2010). Studies of silver species for low-temperature CO oxidation on Ag/SiO2 catalysts. Separation and Purification Technology, 72(3), 395-400. doi:10.1016/j.seppur.2010.03.012Kolobova, E., Pestryakov, A., Mamontov, G., Kotolevich, Y., Bogdanchikova, N., Farias, M., … Cortes Corberan, V. (2017). Low-temperature CO oxidation on Ag/ZSM-5 catalysts: Influence of Si/Al ratio and redox pretreatments on formation of silver active sites. Fuel, 188, 121-131. doi:10.1016/j.fuel.2016.10.037Ausavasukhi, A., Suwannaran, S., Limtrakul, J., & Sooknoi, T. (2008). Reversible interconversion behavior of Ag species in AgHZSM-5: XRD, 1H MAS NMR, TPR, TPHE, and catalytic studies. 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A., López, J. M. R., & Boix, A. V. (2013). Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques. The Journal of Physical Chemistry C, 117(48), 25433-25442. doi:10.1021/jp4046269Veronesi, G., Deniaud, A., Gallon, T., Jouneau, P.-H., Villanova, J., Delangle, P., … Michaud-Soret, I. (2016). Visualization, quantification and coordination of Ag+ions released from silver nanoparticles in hepatocytes. Nanoscale, 8(38), 17012-17021. doi:10.1039/c6nr04381jVeronesi, G., Aude-Garcia, C., Kieffer, I., Gallon, T., Delangle, P., Herlin-Boime, N., … Carrière, M. (2015). Exposure-dependent Ag+release from silver nanoparticles and its complexation in AgS2sites in primary murine macrophages. Nanoscale, 7(16), 7323-7330. doi:10.1039/c5nr00353aHudson-Smith, N. V., Clement, P. L., Brown, R. P., Krause, M. O. P., Pedersen, J. A., & Haynes, C. L. (2016). Research highlights: speciation and transformations of silver released from Ag NPs in three species. Environmental Science: Nano, 3(6), 1236-1240. doi:10.1039/c6en90025aShimizu, K., Sugino, K., Kato, K., Yokota, S., Okumura, K., & Satsuma, A. (2007). Formation and Redispersion of Silver Clusters in Ag-MFI Zeolite as Investigated by Time-Resolved QXAFS and UV−Vis. The Journal of Physical Chemistry C, 111(4), 1683-1688. doi:10.1021/jp066995aChen, D., Qu, Z., Shen, S., Li, X., Shi, Y., Wang, Y., … Wu, J. (2011). Comparative studies of silver based catalysts supported on different supports for the oxidation of formaldehyde. Catalysis Today, 175(1), 338-345. doi:10.1016/j.cattod.2011.03.059Schuricht, F., & Reschetilowski, W. (2012). Simultaneous selective catalytic reduction (SCR) of NOx and N2O over Ag/ZSM-5 – Catalytic studies and mechanistic implications. Microporous and Mesoporous Materials, 164, 135-144. doi:10.1016/j.micromeso.2012.07.018Akolekar, D. B., & Bhargava, S. K. (2000). 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Combinatorial RNA Design: Designability and Structure-Approximating Algorithm
In this work, we consider the Combinatorial RNA Design problem, a minimal
instance of the RNA design problem which aims at finding a sequence that admits
a given target as its unique base pair maximizing structure. We provide
complete characterizations for the structures that can be designed using
restricted alphabets. Under a classic four-letter alphabet, we provide a
complete characterization of designable structures without unpaired bases. When
unpaired bases are allowed, we provide partial characterizations for classes of
designable/undesignable structures, and show that the class of designable
structures is closed under the stutter operation. Membership of a given
structure to any of the classes can be tested in linear time and, for positive
instances, a solution can be found in linear time. Finally, we consider a
structure-approximating version of the problem that allows to extend bands
(helices) and, assuming that the input structure avoids two motifs, we provide
a linear-time algorithm that produces a designable structure with at most twice
more base pairs than the input structure.Comment: CPM - 26th Annual Symposium on Combinatorial Pattern Matching, Jun
2015, Ischia Island, Italy. LNCS, 201
Pro-and Anti-Inflammatory Cytokines Release in Mice Injected with Crotalus durissus terrificus Venom
The effects of Crotalus durissus terrificus venom (Cdt) were analyzed with respect to the susceptibility and the inflammatory mediators in an experimental model of severe envenomation. BALB/c female mice injected intraperitoneally presented sensibility to Cdt, with changes in specific signs, blood biochemical and inflammatory mediators. The venom induced reduction of glucose and urea levels and an increment of creatinine levels in serum from mice. Significant differences were observed in the time-course of mediator levels in sera from mice injected with Cdt. The maximum levels of IL-6, NO, IL-5, TNF, IL-4 and IL-10 were observed 15 min, 30 min, 1, 2 and 4 hours post-injection, respectively. No difference was observed for levels of IFN-γ. Taken together, these data indicate that the envenomation by Cdt is regulated both pro-and anti-inflammatory cytokine responses at time-dependent manner. In serum from mice injected with Cdt at the two first hours revealed of pro-inflammatory dominance. However, with an increment of time an increase of anti-inflammatory cytokines was observed and the balance toward to anti-inflammatory dominance. In conclusion, the observation that Cdt affects the production of pro-and anti-inflammatory cytokines provides further evidence for the role played by Cdt in modulating pro/anti-inflammatory cytokine balance
Pro- and Anti-Inflammatory Cytokines Release in Mice Injected with Crotalus durissus terrificus
Isoscalar off-shell effects in threshold pion production from pd collisions
We test the presence of pion-nucleon isoscalar off-shell effects in the
reaction around the threshold region. We find that these
effects significantly modify the production cross section and that they may
provide the missing strength needed to reproduce the data at threshold.Comment: 6 pages, REVTeX, twocolumn, including 3 figures (Postscript), uses
psfig, updated and extended versio
Working towards a consensus on the oncological approach of breakthrough pain: A Delphi survey of Spanish experts
Purpose: There is a lack of standards for the diagnosis, assessment and management of breakthrough cancer pain (BTcP). La Fundación ECO (the Foundation for Excellence and Quality in Oncology) commissioned a study to establish a consensus and lay the foundations for the appropriate management of BTcP in oncology patients.
Patients and methods: A modified Delphi survey comprising two rounds was used to gather and analyze data, which was conducted over the Internet. Each statement that reached a consensus with the respondents was defined as a median consensus score (MED) of =7, and agreement among panelists as an interquartile range (IQR) of =3.
Results: In total, 69 medical oncologists responded, with a broad consensus that BTcP implied exacerbations of high-intensity pain, as opposed to moderate pain. Furthermore, they concurred that appropriate diagnostic equipment is needed, and that rapid-onset fentanyl formulations should be the preferred treatment for BTcP management. The panelists agreed that a lack of appropriate information and training to attend to patients, as well as limited patient visitation rights, were barriers to effective BTcP management. Regarding gaps in detected knowledge, the panelists were unsure of the measures necessary to assess the burden of the disease on the patient’s quality of life and associated medication costs. Alongside this, there was a lack of awareness of the technical specifics of the different formulations of rapid-onset fentanyl.
Conclusion: These results represent the current status of BTcP management. They may inform recommendations and provide a framework for future research
A primordial star in the heart of the Lion
Context: The discovery and chemical analysis of extremely metal-poor stars
permit a better understanding of the star formation of the first generation of
stars and of the Universe emerging from the Big Bang. aims: We report the study
of a primordial star situated in the centre of the constellation Leo (SDSS
J102915+172027). method: The star, selected from the low resolution-spectrum of
the Sloan Digital Sky Survey, was observed at intermediate (with X-Shooter at
VLT) and at high spectral resolution (with UVES at VLT). The stellar parameters
were derived from the photometry. The standard spectroscopic analysis based on
1D ATLAS models was completed by applying 3D and non-LTE corrections. results:
An iron abundance of [Fe/H]=--4.89 makes SDSS J102915+172927 one of the lowest
[Fe/H] stars known. However, the absence of measurable C and N enhancements
indicates that it has the lowest metallicity, Z<= 7.40x10^{-7} (metal-mass
fraction), ever detected. No oxygen measurement was possible. conclusions: The
discovery of SDSS J102915+172927 highlights that low-mass star formation
occurred at metallicities lower than previously assumed. Even lower metallicity
stars may yet be discovered, with a chemical composition closer to the
composition of the primordial gas and of the first supernovae.Comment: To be published in A&
Spitzer/IRAC view of Sh 2-284: Searching for evidence of triggered star formation in an isolated region in the outer Milky Way
Using Spitzer/IRAC observations of a region to be observed by the CoRoT
satellite, we have unraveled a new complex star-forming region at low
metallicity in the outer Galaxy. We perform a study of S284 in order to outline
the chain of events in this star-forming region. We used four-band Spitzer/IRAC
photometry as well as Halpha imaging obtained with INT/WFC. Combining these
data with the optical photometry obtained in the frame of CoRoTs preparation
and the 2MASS catalog we analysed the properties and distribution of young
stellar objects (YSOs) associated with point-like sources. We also studied the
SEDs of regions of extended emission, complementing our dataset with IRAS and
MSX data. We find that S284 is unique in several ways: it is very isolated at
the end of a spiral arm and both the diffuse dust and ionized emission are
remarkably symmetric. We have partially resolved the central clusters of the
three bubbles present in this region. Despite the different scales present in
its multiple-bubble morphology, our study points to a very narrow spread of
ages among the powering high-mass clusters. In contrast, the particular
sawtooth structure of the extended emission at the rim of each ionized bubble
harbours either small lower-mass clusters with a younger stellar population or
individual young reddened protostars. In particular, triggered star formation
is considered to be at work in these regions.Comment: Accepted by A&A. 13 pages, 10 figures, 2 Table
Origin of the inverse spin-switch behavior in manganite/cuprate/manganite trilayers
We studied ferromagnet/superconductor/ferromagnet trilayers based on La_(0.7)Ca_(0.3)MnO_(3) manganite and YBa_(2)Cu_(3)O_(7−δ) (YBCO) high-T_(c) cuprate with magnetoresistance and magnetization measurements. We find an inverse superconducting spin-switch behavior, where superconductivity is favored for parallel alignment of the magnetization in the ferromagnetic layers. We argue that this inverse superconducting spin switch originates from the transmission of spin-polarized carriers into the superconductor. In this picture, the thickness dependence of the magnetoresistance yields the spin-diffusion length in YBCO as 13 nm. A comparison of bilayers and trilayers allows ruling out the effect of the stray fields of the domain structure of the ferromagnet as the source of the inverse superconducting spin switch
Potential Use of Near-Infrared Spectroscopy to Predict Fatty Acid Profile of Meat from Different European Autochthonous Pig Breeds
Autochthonous pig breeds provide products of differentiated quality, among which quality control is difficult to perform and insufficient for current market requirements. The present research evaluates the predictive ability of near‐infrared (NIR) spectroscopy, combined with chemometric methods as a rapid and affordable tool to assure traceability and quality control. Thus, NIR technology was assessed for intact and minced muscle Longissimus thoracis et lumborum samples collected from 12 European autochthonous pig breeds for the quantification of lipid content and fatty acid composition. Different tests were performed using different numbers of samples for calibration and validation. The best predictive ability was found using minced presentation and set with 80% of the samples for the calibration and the remaining 20% for the external validation test for the following traits: lipid content and saturated and polyunsaturated fatty acids, which attained both the highest determination coefficients (0.89, 0.61, and 0.65, respectively) and the lowest root mean square errors in external validation (0.62, 1.82, and 1.36, respectively). Lower predictive ability was observed for intact muscles. These results could contribute to improve the management of autochthonous breeds and to ensure quality of their products by traditional meat industry chains
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