268 research outputs found
Electropolishing Valve Metals with a Sulfuric Acid-Methanol Electrolyte at Low Temperature
This study reports the electropolishing Ti and Nb metals using a fluoride-free electrolyte of sulfuric acid and methanol at low temperature (-70°C) without prior treatment. A fluoride-free electrolyte provides a less hazardous and more environmentally friendly option for electropolishing procedure. Experimental studies are presented on electropolishing with sulfuric acid electrolyte, which provides high quality macro- and micro-smoothing of the metal surfaces. Optimal conditions yielded leveling and brightening of the surface of Ti and Nb metals beyond that of the currently utilized electropolishing procedures with fluoride-containing electrolytes. The root mean squared roughness (Rq) from atomic force microscopy (AFM) analysis was 1.64 and 0.49 nm for Ti and Nb, respectively. Lower temperature experiments led to noticeable kinetic effects, indicated by a dramatic drop in current densities and the expansion of the steady-state current density plateau in anodic polarization curves. In addition, the voltage range of the current plateau expanded with increasing acid concentration. Surface characterization of Ti and Nb metals after polishing provided evidence of salt film formation. In addition, these metals were used as substrates in the formation of nanostructured metal oxides. The overall quality of the polishing led to a dramatic improvement in the uniformity of the nanostructures
Triterpenic Acids and Flavonoids from Satureja parvifolia: Evaluation of their Antiprotozoal Activity
Bioassay-guided fractionation of a Satureja parvifolia MeOH extract led to the isolation of eriodictyol, luteolin and ursolic and oleanolic acids as its active components against Plasmodium falciparum K1. This is the first time these compounds are reported as constituents of S. parvifolia. Ursolic acid showed an IC50 of 4.9,Mg/ml, luteolin 6.4,μg/ml, oleanolic acid 9.3,μg/ml and eriodictyol 17.2,μg/ml. Antiplasmodial activity of eriodictyol and luteolin is reported here for the first time. Besides, the four compounds showed activity against P falciparum 3D7 strain and Trypanosoma brucei rhodesiense. Eriodictyol showed moderate activity on all the parasites but was the most selective compound as a result of its rather low cytotoxicity (IC50 174.2,μg/ml) on the mammalian KB cell line.Facultad de Ciencias Exacta
Retrieving opinions from discussion forums
Understanding the landscape of opinions on a given topic or issue is important for policy makers, sociologists, and intelligence analysts. The first step in this process is to retrieve relevant opinions. Discussion forums are potentially a good source of this information, but comes with a unique set of retrieval challenges. In this short paper, we test a range of existing techniques for forum retrieval and develop new retrieval models to differentiate between opinionated and factual forum posts. We are able to demonstrate some significant performance improvements over the baseline retrieval models, demonstrating that this as a promising avenue for further study. Copyright is held by the owner/author(s).EI
Triterpenic Acids and Flavonoids from Satureja parvifolia: Evaluation of their Antiprotozoal Activity
Bioassay-guided fractionation of a Satureja parvifolia MeOH extract led to the isolation of eriodictyol, luteolin and ursolic and oleanolic acids as its active components against Plasmodium falciparum K1. This is the first time these compounds are reported as constituents of S. parvifolia. Ursolic acid showed an IC50 of 4.9,Mg/ml, luteolin 6.4,μg/ml, oleanolic acid 9.3,μg/ml and eriodictyol 17.2,μg/ml. Antiplasmodial activity of eriodictyol and luteolin is reported here for the first time. Besides, the four compounds showed activity against P falciparum 3D7 strain and Trypanosoma brucei rhodesiense. Eriodictyol showed moderate activity on all the parasites but was the most selective compound as a result of its rather low cytotoxicity (IC50 174.2,μg/ml) on the mammalian KB cell line.Facultad de Ciencias Exacta
Large scale anisotropies on halo infall
We perform a statistical analysis of the peculiar velocity field around dark
matter haloes in numerical simulations. We examine different properties of the
infall of material onto haloes and its relation to central halo shapes and the
shape of the large scale surrounding regions (LSSR). We find that the amplitude
of the infall velocity field along the halo shape minor axis is larger than
that along the major axis. This is consistent for general triaxial haloes, and
for both prolate and oblate systems. We also report a strong anisotropy of the
velocity field along the principal axes of the LSSR. The infall velocity field
around dark matter haloes reaches a maximum value along the direction of the
minor axis of the LSSR, whereas along the direction of its major axis, it
exhibits the smallest velocities. We also analyse the dependence of the matter
velocity field on the local environment. The amplitude of the infall velocity
at high local density regions is larger than at low local density regions. The
velocity field tends to be more laminar along the direction towards the minor
axis of the LSSR, where the mean ratio between flow velocity and velocity
dispersion is of order unity and nearly constant up to scales of 15 Mpc/h. We
also detect anisotropies in the outflowing component of the velocity field,
showing a maximum amplitude along the surrounding LSSR major axis.Comment: 12 pages, 9 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Societ
Reviews
The Collected Poems of C.S. Lewis: A Critical Edition. Edited by Don W. King. Reviewed by Joe R. Christopher.
Tree of Salvation: Yggdrasil and the Cross in the North. G. Ronald Murphy. Reviewed by Jon Garrad.
Anglo-Saxon Community in J.R.R. Tolkien\u27s The Lord of the Rings. Deborah A. Higgins. Reviewed by Yvette Kisor.
Surprised by the Feminine: A Rereading of C.S. Lewis and Gender. Monika B. Hilder. Reviewed by Laura Lee Smith.
Arda Inhabited: Environmental Relationships in The Lord of The Rings. Susan Jeffers. Reviewed by Jeremy Larson.
Joy: Poet, Seeker, and the Woman Who Captivated C.S. Lewis. Abigail Santamaria. Reviewed by Crystal Hurd.
A Naked Tree: Love Sonnets to C.S. Lewis and Other Poems. Joy Davidman. Ed. Don W. King. Reviewed by Joe R. Christopher.
The Hero Enkidu. Lewis Turco. Reviewed by Nicholas Birns.
Encyclopedia of Goddesses & Heroines. Patricia Monaghan. Reviewed by Cait Coker.
The Oxford Inklings. Colin Duriez. Reviewed by Crystal Hurd.
The Fellowship: The Literary Lives of the Inklings. Philip Zaleski and Carol Zaleski. Reviewed by Crystal Hurd.
The Pilgrim\u27s Regress: Wade Annotated Edition. C.S. Lewis. Edited and introduced by David C. Downing. Reviewed by Mike Foster.
North Wind: A Journal of George MacDonald Studies. Editors John Pennington and Fernando Soto. Reviewed by Janet Brennan Croft.
Supernatural Studies. Special Issue: Television and the Supernatural. Editor Leah Richards; Guest editor Marisa C. Hayes. Reviewed by Janet Brennan Croft.
Journal of Inklings Studies: Theology, Philosophy, Literature. Special Issue: Inklings and the Bible. Executive editor Judith Wolfe. Reviewed by Janet Brennan Croft
Nestor-Guillermo Progeria Syndrome: a biochemical insight into Barrier-to-Autointegration Factor 1, alanine 12 threonine mutation
Background - Premature aging syndromes recapitulate many aspects of natural aging and provide an insight into this phenomenon at a molecular and cellular level. The progeria syndromes appear to cause rapid aging through disruption of normal nuclear structure. Recently, a coding mutation (c.34G > A [p.A12T]) in the Barrier to Autointegration Factor 1 (BANF1) gene was identified as the genetic basis of Néstor-Guillermo Progeria syndrome (NGPS). This mutation was described to cause instability in the BANF1 protein, causing a disruption of the nuclear envelope structure. Results - Here we demonstrate that the BANF1 A12T protein is indeed correctly folded, stable and that the observed phenotype, is likely due to the disruption of the DNA binding surface of the A12T mutant. We demonstrate, using biochemical assays, that the BANF1 A12T protein is impaired in its ability to bind DNA while its interaction with nuclear envelope proteins is unperturbed. Consistent with this, we demonstrate that ectopic expression of the mutant protein induces the NGPS cellular phenotype, while the protein localizes normally to the nuclear envelope. Conclusions - Our study clarifies the role of the A12T mutation in NGPS patients, which will be of importance for understanding the development of the disease
Structure-based design, synthesis and biological evaluation of a novel series of isoquinolone and pyrazolo[4,3-c]pyridine inhibitors of fascin 1 as potential anti-metastatic agents
Fascin is an actin binding and bundling protein that is not expressed in normal epithelial tissues but overexpressed in a variety of invasive epithelial tumors. It has a critical role in cancer cell metastasis by promoting cell migration and invasion. Here we report the crystal structures of fascin in complex with a series of novel and potent inhibitors. Structure-based elaboration of these compounds enabled the development of a series with nanomolar affinities for fascin, good physicochemical properties and the ability to inhibit fascin-mediated bundling of filamentous actin. These compounds provide promising starting points for fascin-targeted anti-metastatic therapies
LUCIFER@LBT view of star-forming galaxies in the cluster 7C 1756+6520 at z~1.4
Galaxy clusters are key places to study the contribution of {\it nature}
(i.e. mass, morphology) and {\it nurture} (i.e.environment) in the formation
and evolution of galaxies. Recently, a number of clusters at z1, i.e.
corresponding to the first epochs of the cluster formation, has been discovered
and confirmed spectroscopically. We present new observations obtained with the
{\sc LUCIFER} spectrograph at Large Binocular Telescope (LBT) of a sample of
star-forming galaxies associated with a large scale structure around the radio
galaxy 7C1756+6520 at z=1.42. Combining our spectroscopic data and the
literature photometric data, we derived some of the properties of these
galaxies: star formation rate, metallicity and stellar mass. With the aim of
analyzing the effect of the cluster environment on galaxy evolution, we have
located the galaxies in the plane of the so-called Fundamental Metallically
Relation (FMR), which is known not to evolve with redshift up to z for
field galaxies, but it is still unexplored in rich environments at low and high
redshift. We found that the properties of the galaxies in the cluster 7C
1756+6520 are compatible with the FMR which suggests that the effect of the
environment on galaxy metallicity at this early epoch of cluster formation is
marginal. As a side study, we also report the spectroscopic analysis of a
bright AGN, belonging to the cluster, which shows a significant outflow of gas.Comment: Accepted for publication by MNRAS, 10 pages, 6 figures, 3 table
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