255 research outputs found
Architekton en Manhattan
Architekton en Manhattan es un trabajo que describe y relata una situación histórica,
cultural y política de los años 20 entre Estados Unidos y Rusia a través del estudio del
fotomontaje manual realizado por Kazimir Malevich: “Architekton in Front of a Skyscraper
(Suprematist transformation of New York)”. Este trabajo busca entender la dialéctica y el
símbolo de qué significaba para el artista superponer una axonométrica en una fotografía
del sector financiero de Manhattan, cuál era el mensaje detrás de esta intervención.
Abstract: Manhattan’s Architekton is a descriptive work about a historic, cultural and
politic situation amid 1920’s between United States and Russia constructed through the
study of the handcrafted photomontage by Kazimir Malevich: “Architekton in Front of a
Skyscraper (Suprematist transformation of New York)”. This work pursues the understanding
the dialectic and iconography of what really meant to the artist the juxtaposition of an
axonometric into a photography of Manhattan’s financial district, what was the true
message behind this intervention
Utility of Masson’s Trichrome Stain in the Quantification of Mean Vascular Density in Normal Oral Mucosa, Epithelial Dysplasia and Oral Squamous Cell Carcinoma
Indexación: Scopus; Scielo.El objetivo de este estudio fue valuar la utilidad del uso de la tinción de Tricrómico de Masson (TM) en la cuantificación de la densidad media vascular (DMV) en Mucosa Oral Normal (MON), Displasia Epitelial Oral (DEO) y Carcinoma Oral de Células Escamosas (COCE). Estudio descriptivo de serie de casos. Se analizaron 17 muestras de MON, 15 muestras de DEO y 16 de COCE, teñidas con TM. Para determinar su utilidad, se compararon con las mismas muestras analizadas con técnica de inmunohistoquímica contra CD31. La cuantificación de la DMV se realizó en las 3 áreas de mayor vascularización de cada muestra. Se determinó la DMV según diagnóstico mediante la tinción TM e inmunohistoquímica contra CD31, y se calculó la correlación entre ambos. La DMV cuantificada con TM y contra CD31 difiere según el diagnóstico, observándose un aumento de la DMV al malignizarse el diagnóstico. No se encontraron diferencias al comparar la DMV cuantificada con TM y contra CD31. La correlación de la DMV analizado por TM y contra CD31 es significativa y moderada. La cuantificación de vasos sanguíneos es posible mediante la tinción de TM en muestras de MON, DEO y COCE, con una correlación moderada con la inmunohistoquímica contra CD31.The objective of this study was to evaluate the utility of Masson's Trichrome (TM) staining in the quantification of the mean vascular density (DMV) in samples of normal oral mucosa (MON), oral epithelial dysplasia (ODE) and oral squamous cell carcinoma (COCE). The design - a descriptive study of case series. We analyzed 17 samples of MON, 15 samples of DEO and 16 samples of COCE, stained with TM. To determine usefulness, we compared and analyzed the same samples, either stained with TM or with immunohistochemical technique against CD31. Quantification of the DMV was performed in the 3 areas of greatest vascularization in each sample. DMV was determined according to diagnosis by TM staining and immunohistochemistry against CD31, and the correlation between the two was then calculated. DMV quantified with TM and against CD31 differs according to the diagnosis, with an increase in DMV upon malignant diagnosis. No differences were found when comparing DMV quantified with TM and against CD31. The correlation of the DMV analyzed by TM and against CD31 is significant and moderate. Quantification of blood vessels is possible by TM staining in samples of MON, DEO and COCE. TM staining is moderately correlated with immunohistochemistry against CD31.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-95022017000401576&lng=en&nrm=iso&tlng=e
Synthesis and NMR structure determination of new linear geranylphenols by direct geranylation of activated phenols.
Indexación: Web of Science; ScieloThe known geranylhydroquinone 2, geranylorcinol 4 and the derivative (E)-4-(3,7-dimethylocta-2,6-dienyl)-5-methylbenzene-1,3-diol 5, were prepared by Electrophilic Aromatic Substitution (EAS) reactions between the corresponding phenol derivatives containing electron-donor subtituents and geraniol using BF3XOEt2 as a catalyst. In addition, spectroscopic NMR information for 4 and 5 is complemented. Furthermore, the new (E)-2-(3,7-dimethylocta-2,6-dienyl) benzene-1,3,5-triol (geranylphloroglucinol) 13, (E)-2-(3,7-dimethylocta-2,6-dienyl)-1,3,5-trimethoxybenzene 14, (E)-2-(3,7-dimethylocta-2,6-dienyl)-6-methoxyphenol 15, (E)-3-(3,7-dimethylocta-2,6-dienyl)-2-methoxyphenol 16, (E)-5-(3,7-dimethylocta-2,6-dienyl)-2-methoxyphenol 17, (E)-4-(3,7-dimethylocta-2,6-dienyl)benzene-1,3-diol 18, (E)-3-(3,7-dimethylocta-2,6-dienyl)benzene-1,2-diol 19, (E)-4-(3,7-dimethylocta-2,6-dienyl)-5-isopropyl-2-methylphenol 20, (E)-2-(3,7-dimethylocta-2,6-dienyl)-4-isopropyl-3-methylphenol 21, (E)-2-(3,7-dimethylocta-2,6-dienyl)-4-isopropyl-5-methylphenol 22, and(E)-2-tert-butyl-4-(3,7-dimethylocta-2,6-dienyl)-5-methylphenol 23 were also prepared with this synthesis strategy. All the synthesized compounds were fully characterized and their structures were established by IR, MS and mainly NMR spectroscopic dates.http://ref.scielo.org/3cj5t
Magnetic and electronic Co states in layered cobaltate GdBaCo2O5.5-x
We have performed non-resonant x-ray diffraction, resonant soft and hard
x-ray magnetic diffraction, soft x-ray absorption and x-ray magnetic circular
dichroism measurements to clarify the electronic and magnetic states of the
Co3+ ions in GdBaCo2O5.5. Our data are consistent with a 3+ Py Co HS state at
the pyramidal sites and a 3+ Oc Co LS state at the octahedral sites. The
structural distortion, with a doubling of the a axis (2ap x 2ap x 2ap cell),
shows alternating elongations and contractions of the pyramids and indicates
that the metal-insulator transition is associated with orbital order in the t2g
orbitals of the 3+ Py Co HS state. This distortion corresponds to an
alternating ordering of xz and yz orbitals along the a and c axes for the 3+ Py
Co . The orbital ordering and pyramidal distortion lead to deformation of the
octahedra, but the 3+ Oc Co LS state does not allow an orbital order to occur
for the 3+ Oc Co ions. The soft x-ray magnetic diffraction results indicate
that the magnetic moments are aligned in the ab plane but are not parallel to
the crystallographic a or b axes. The orbital order and the doubling of the
magnetic unit cell along the c axis support a non-collinear magnetic structure.
The x-ray magnetic circular dichroism data indicate that there is a large
orbital magnetic contribution to the total ordered Co moment
Experimental magnetic form factors in Co3V2O8: A combined study of ab initio calculations, magnetic Compton scattering and polarized neutron diffraction
We present a combination of ab initio calculations, magnetic Compton
scattering and polarized neutron experiments, which elucidate the density
distribution of unpaired electrons in the kagome staircase system Co3V2O8. Ab
initio wave functions were used to calculate the spin densities in real and
momentum space, which show good agreement with the respective experiments. It
has been found that the spin polarized orbitals are equally distributed between
the t2g and the eg levels for the spine (s) Co ions, while the eg orbitals of
the cross-tie (c) Co ions only represent 30% of the atomic spin density.
Furthermore, the results reveal that the magnetic moments of the cross-tie Co
ions, which are significantly smaller than those of the spine Co ions in the
zero-field ferromagnetic structure, do not saturate by applying an external
magnetic field of 2 T along the easy axis a, but that the increasing bulk
magnetization originates from induced magnetic moments on the O and V sites.
The refined individual magnetic moments are mu(Co_c)=1.54(4) mu_B,
mu(Co_s)=2.87(3) mu_B, mu(V)=0.41(4) mu_B, mu(O1)=0.05(5) mu_B, mu(O2)=0.35(5)
mu_B, and; mu(O3)=0.36(5) mu_B combining to the same macroscopic magnetization
value, which was previously only attributed to the Co ions
The genetic population structure of Robinson Crusoe Island, Chile
Studies examining genetic conditions common in Latin America are highly underrepresented in the scientific literature. Understanding of the population structure is limited, particularly Chile, in part due to the lack of available population specific data. An important first-step in elucidating disease mechanisms in Latin America countries is to understand the genetic structure of isolated populations. Robinson Crusoe Island (RCI) is a small land mass off the coast of Chile. The current population of over 900 inhabitants are primarily descended from a small number of founders who colonized the island in the late 1800s. Extensive genealogical records can trace the ancestry of almost the entire population. We perform a comprehensive genetic analysis to investigate the ancestry of the island population, examining ancestral mitochondrial and Y chromosome haplogroups, as well as autosomal admixture. Mitochondrial and Y chromosome haplogroups indicated a substantial European genetic contribution to the current RCI population. Analysis of the mitochondrial haplogroups found in the present-day population revealed that 79.1% of islanders carried European haplogroups, compared to 60.0% of the mainland Chilean controls from Santiago. Both groups showed a substantially lower contribution of indigenous haplogroups than expected. Analysis of the Y chromosome haplogroups also showed predominantly European haplogroups detected in 92.3% of male islanders and 86.7% of mainland Chilean controls. Using the near-complete genealogical data collected from the RCI population, we successfully inferred the ancestral haplogroups of 16/23 founder individuals, revealing genetic ancestry from Northern and Southern Europe. As mitochondrial and Y investigations only provide information for direct maternal and paternal lineages, we expanded this to investigate genetic admixture using the autosomes. Admixture analysis identified substantial indigenous genetic admixture in the RCI population (46.9%), higher than that found in the Santiago mainland Chilean controls (43.4%), but lower than a more representative Chilean population (Chile_GRU) (49.1%). Our study revealed the Robinson Crusoe Island population show a substantial genetic contribution for indigenous Chileans, similar to the level reported in mainland Chileans. However, direct maternal and paternal haplogroup analysis revealed strong European genetic contributions consistent with the history of the Island
Arsenite sorption and co-precipitation with calcite
Sorption of As(III) by calcite was investigated as a function of As(III)
concentration, time and pH. The sorption isotherm, i.e. the log As(III) vs. log
[As(OH)3 degrees / Assat] plot is S-shaped and has been modelled on an extended
version of the surface precipitation model. At low concentrations, As(OH)3
degrees is adsorbed by complexation to surface Ca surface sites, as previously
described by the X-ray standing wave technique. The inflexion point of the
isotherm, where As(OH)3 degrees is limited by the amount of surface sites (ST),
yields 6 sites nm-2 in good agreement with crystallographic data. Beyond this
value, the amount of sorbed arsenic increases linearly with solution
concentration, up to the saturation of arsenic with respect to the
precipitation of CaHAsO3(s). The solid solutions formed in this concentration
range were examined by X-ray and neutron diffraction. The doped calcite lattice
parameters increase with arsenic content while c/a ratio remains constant. Our
results made on bulk calcite on the atomic displacement of As atoms along
[0001] direction extend those published by Cheng et al., (1999) on calcite
surface. This study provides a molecular-level explanation for why As(III) is
trapped by calcite in industrial treatments.Comment: 9 page
DD04107-Derived neuronal exocytosis inhibitor peptides: Evidences for synaptotagmin-1 as a putative target
The analgesic peptide DD04107 (Pal-EEMQRR-NH2) and its acetylated analogue inhibit a-calcitonin gene-related peptide (a-CGRP) exocytotic release from primary sensory neurons. Examining the crystal structure of the SNARE-Synaptotagmin-1(Syt1) complex, we hypothesized that these peptides could inhibit neuronal exocytosis by binding to Syt1, hampering at least partially its interaction with the SNARE complex. To address this hypothesis, we first interrogate the role of individual side-chains on the inhibition of a-CGRP release, finding that E1, M3, Q4 and R6 residues were crucial for activity. CD and NMR conformational analysis showed that linear peptides have tendency to adopt a-helical conformations, but the results with cyclic analogues indicated that this secondary structure is not needed for activity. Isothermal titration calorimetry (ITC) measurements demonstrate a direct interaction of some of these peptides with Syt1-C2B domain, but not with Syt7-C2B region, indicating selectivity. As expected for a compound able to inhibit a-CGRP release, cyclic peptide derivative Pal-E-cyclo[EMQK]R-NH2 showed potent in vivo analgesic activity, in a model of inflammatory pain. Molecular dynamics simulations provided a model consistent with KD values for the interaction of peptides with Syt1-C2B domain, and with their biological activity. Altogether, these results identify Syt1 as a potential new analgesic target. © 202
Exome sequencing of an isolated Chilean population affected by Specific Language Impairment (SLI)
Speech and language impairments that are a primary deficit and have no obvious cause (e.g. a comorbid neurological disorder like autism) are diagnosed as Specific Language Impairment (SLI). SLI affects 5–8 % of preschool children and represents a lifelong disability associated with an increased risk of behavioural disorders, social problems and literacy deficits. SLI is highly heritable and twin studies indicate a strong genetic basis. Nonetheless, the underlying genetic mechanisms are expected to be multifactorial and, to date, only three risk variants have been identified. One way to increase the power to detect contributory genetic factors is to study isolated populations derived from relatively recent shared ancestors (founder populations). In 2008, Villanueva described a founder population with a particularly high incidence of SLI (10 times that expected). They inhabit the Robinson Crusoe Island, which lies 677 km to the west of Chile and was colonised in the late 19th century by 8 European and Amerindian families. 77 % of the current island population have a colonising surname and 14 % of marriages involve consanguineous unions. More than 80 % of language impaired individuals can be traced to a pair of founder brothers. This population thus has a short (5-generations) and well documented history and represents a unique resource which could make valuable contributions to the elucidation of genetic mechanisms underpinning SLI. We applied exome sequencing technologies to five language impaired individuals from this population and identified nine nonsynonymous coding changes or splice site mutations that were present in at least three of the five affected individuals sequenced. Sequencing of the entire cohort identified a single non-synonymous coding change that was significantly more frequent in cases than controls (genotype frequencies of 46 and 11 % respectively, p = 4.48 9 10-5). We suggest that this rare coding variant may contribute to the elevated frequency of SLI in this population
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