2,144 research outputs found
MECHANISTIC STUDY OF A RUTHENIUM HYDRIDE COMPLEX OF TYPE [RuH(CO)(N-N)(PR3)2]+ AS CATALYST PRECURSOR FOR THE HYDROFORMYLATION REACTION OF 1-HEXENE
Indexación: Web of Science; Scopus; Scielo.The catalytic activity of systems of type [RuH(CO)(N-N)(PR3)(2)](+) was evaluated in the hydroformylation reaction of 1-hexene. The observed activity is explained through a reaction mechanism on the basis of the quantum theory. The mechanism included total energy calculations for each of the intermediaries of the elemental steps considered in the catalytic cycle. The deactivation of the catalyst precursors takes place via dissociation of the polypyridine ligand and the subsequent formation of thermodynamically stable species, such as RuH(CO)(3)(PPh3)(2) and RuH3(CO)(PPh3)(2), which interrupt the catalytic cycle. In addition, the theoretical study allows to explain the observed regioselectivity which is defined in two steps: (a) the hydride migration reaction with an anti-Markovnikov orientation to produce the alkyl-linear-complex (3.1a), which is more stable by 19.4 kJ/mol than the Markovnikov orientation (alkyl-branched-complex) (3.1b); (b) the carbon monoxide insertion step generates the carbonyl alkyl-linear specie (4.1a) which is more stable by 9.5 kJ/mol than the alternative species (4.1b), determining the preferred formation of heptanal in the hydroformylation of 1-hexene.
Palabras clavehttp://ref.scielo.org/db4yc
Validity of a four-factor modelunderlying the physical fitness in adults with intellectual disabilities a confirmatory factor analysis
Purpose: To use confirmatory factor analysis to test whether a four factor might explain the clustering of the components of the physical fitness in adults with intellectual disabilities (FID).
Relevance: Individuals with intellectual disabilities (ID) are significantly weaker than individuals without ID at all stages of life. These subjects might be particularly susceptible to loss of basic function because of poor physical fitness.
Participants: We studied 267 adults with intellectual disability of the Spanish Special Olympics Games.
Methods: The four-factor model included: the flexibility, the strength, the balance and the cardiorespiratory endurance with 9 variables of the fitness assessment.
Analysis: The construct validity of the model was assessed through the factor loadings, interpreted as the correlation between the variables in the model and their underlying factor, which is the FID construct.
Results: Factor loading were 0,55 for the passive knee extension, o,52 for Functional shoulder rotation, −0.71 for the timed-stand test, 0.58 for the grip test, 0.75 the single leg stance with eyes open, 0.69 single leg stance with eyes closed, 0.72 for the resting heart rate, 0.56 for the two-minute step test (2MST) 0,97 for 2 minutes after finish 2MST. The four-factor model also showed a good fit to the data, as indicated by a high comparative fit index (CFI=0,93) and a low standardized root mean square residual (SRMR=0,072)
Conclusions: A four underlying factor has shown acceptable validity to represent FID
Implications: The new model of FID can offer understanding better these construct in this special populationUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Multicorporalidad frente a ocularcentrismo: de la ciudad ojo-individuo a la ciudad sensorial-participada
Algunos autores/as, como Jay (1988, 2003, 2007, 2008), Levin (1988, 1993) o Jenks (1995), han investigado acerca de la influencia del ocularcentrismo en la cultura occidental. Otros/as, como Pallasmaa (2006), han especificado esta influencia en el ámbito arquitectónico y urbanístico. Finalmente, a partir de la década de los ochenta, la antropología sensorial cuestionó el visualismo del pensamiento y cultura occidentales, haciendo hincapié en trascender este sesgo con el fin de conectar con la experiencia cultural de los sujetos no occidentales. Sin embargo, y atendiendo a los avances en esta última disciplina, las taxonomías de los sentidos en las culturas responden a un orden cultural y social determinado por la asignación de mayor o menor valor a nuestros sentidos. ¿Y si cuestionamos dicha taxonomía ocularcéntrica dentro de nuestra propia cultura occidental, valiéndonos de las experiencias de los cuerpos que resisten a dicha jerarquización?
En este artículo se analiza cómo se gestó el ocularcentrismo en la Modernidad y cómo continúa siendo el principal paradigma en la construcción de las ciudades. Más tarde, atendiendo al desmontaje de dichas taxonomías de la mano de la antropología sensorial y utilizando la multiplicidad de tecnologías que en nuestro tiempo permiten la sinestesia e interdependencia de los sentidos, se presenta un proyecto multisensorial para habitar la ciudad. Este proyecto tiene por objetivo facilitar a los participantes habitar los espacios urbanos de maneras diversas, alejadas de las formas normalizadas de interacción.
Certain authors, such as Jay (1988, 2003, 2007, 2008), Levin (1988, 1993) and Jenks (1995), have investigated the influence of ocular-centrism in Western culture. Others such as Pallasmaa (2006) have specifically considered this influence in the architectural and planning context. Finally and since the 1980s, sensory anthropology has questioned the visualism of Western thought and culture, emphasising a need to transcend this bias in order to connect with the cultural experience of non-Western subjects. However, and taking into account the advances of the latter field, cultural taxonomies of the senses follow a cultural and social order that is determined by the assignment of greater or lesser value to our senses. But we may use the experience of bodies that resist this hierarchical process to question the ocular-centric taxonomy present in our own Western culture. This article analyses how ocular-centrism was managed in modernity and how it remains the main paradigm in the construction of the cities. The paper then presents a multisensorial project for inhabiting cities based on the dismantling of said taxonomies through sensory anthropology, making use of the range of contemporary technologies that permit synaesthesia and the interdependence of our senses. The aim of this project is to enable participants to inhabit urban spaces in diverse ways that differ from the normalised forms of interaction
Multiphoton processes via conditional measurements in the two-field interaction
In this contribution, we show that the use of conditional measurements in the
resonant interaction of two quantized electromagnetic fields gives rise to
nonclassical multiphoton processes. Furthermore, we demonstrate that this
phenomenon may enable a robust integrated-optics protocol to engineer quantum
states containing a high number of photons, thus making it a potentially
appealing platform for exploring mesoscopic quantum phenomena.Comment: 12 pages, 6 figure
Analysis of the role of AMPK activity as the possible cause of the longevity phenotype of the sul-2 mutants
Aging is a biological process caused by cell impairment that increase susceptibility to diseases and death. Some of these diseases, such as Alzheimer or Parkinson, are originated by loss of proteostasis and the generation of protein aggregates. Sulfated steroid hormones are of great importance in the maintenance of proteostasis, and by inhibiting the steroid sulfatase enzyme, it is possible to generate a reservoir of sulfated hormones that prevents cells from generating protein aggregates. Loss of function of the steroid sulfatase sul-2 gene has been proved to increase longevity and to ameliorate protein aggregates diseases in Caenorhabditis elegans. To explain the metabolic pathways involved in this process, two RNAseq have been performed with sul-2 mutants and the resulting data were uploaded to WormExp, where it was found that sul-2 mutants share expression patterns with AMPK activation mutants (Pérez-Jiménez et al. (2021)). AMPK activation mutants are also long-lived (Burkewizt et al. 2016), which suggests that AMPK activity could cause the sul-2 increased-longevity phenotype. To improve the understanding of this subject, we have backcrossed three times AMPK deficient hermaphrodite aak2-(ok524) with N2 males obtaining a deficient mutant with a known background. In the following experiments we will try to confirm the similar expression pattern of AMPK and sul-2 mutants and then will be evaluated the role of AMPK in sul-2 mutant longevity and proteostasis. In addition, we are evaluating other phenotypes of the sul-2 mutants, in particular stress resistance
Coherent Quantum Transport in Photonic Lattices
Transferring quantum states efficiently between distant nodes of an
information processing circuit is of paramount importance for scalable quantum
computing. We report on the first observation of a perfect state transfer
protocol on a lattice, thereby demonstrating the general concept of trans-
porting arbitrary quantum information with high fidelity. Coherent transfer
over 19 sites is realized by utilizing judiciously designed optical structures
consisting of evanescently coupled waveguide ele- ments. We provide unequivocal
evidence that such an approach is applicable in the quantum regime, for both
bosons and fermions, as well as in the classical limit. Our results illustrate
the potential of the perfect state transfer protocol as a promising route
towards integrated quantum computing on a chip
Mapping Bromodomains in breast cancer and association with clinical outcome
A specific family of proteins that participate in epigenetic regulation is the bromodomain (BRD) family of proteins. In this work, we aimed to explore the expression of the BRD family at a transcriptomic level in breast cancer, and its association with patient survival. mRNA level data from normal breast and tumor tissues were extracted from public datasets. Gene set enrichment analysis (GSEA) was performed to identify relevant biological functions. The KM Plotter Online tool was used to evaluate the relationship between the presence of different genes and patient clinical outcome. mRNA level data from HER2+ breast cancer patients sensible and resistant to trastuzumab were also evaluated. The BRD family was an enriched function. In HER2 positive tumors the combined analyses of BRD2, BAZ1A, TRIM33 and ZMYND8 showed a detrimental relapse free survival (RFS). Similarly, the combined analysis of BRD2, BAZ1A, PHIP, TRIM33, KMT2A, ASH1L, PBRM1, correlated with an extremely poor overall survival (OS). The prognosis was confirmed using an independent dataset from TCGA. Finally, no relation between expression of BRD genes and response to trastuzumab was observed in the HER2 population. Upregulation of some BRD genes is associated with detrimental outcome in HER2 positive tumors, regardless trastuzumab treatment
Severity-Related Changes of Bronchial Microbiome in Chronic Obstructive Pulmonary Disease
Bronchial colonization by potentially pathogenic microorganisms (PPMs) is often demonstrated in chronic obstructive pulmonary disease (COPD), but culture-based techniques identify only a portion of the bacteria in mucosal surfaces. The aim of the study was to determine changes in the bronchial microbiome of COPD associated with the severity of the disease. The bronchial microbiome of COPD patients was analyzed by 16S rRNA gene amplification and pyrosequencing in sputum samples obtained during stable disease. Seventeen COPD patients were studied (forced expiratory volume in the first second expressed as a percentage of the forced vital capacity [FEV1%] median, 35.0%; interquartile range [IQR], 31.5 to 52.0), providing a mean of 4,493 (standard deviation [SD], 2,598) sequences corresponding to 47 operational taxonomic units (OTUs) (SD, 17) at a 97% identity level. Patients were dichotomized according to their lung function as moderate to severe when their FEV1% values were over the median and as advanced when FEV1% values were lower. The most prevalent phyla in sputum were Proteobacteria (44%) and Firmicutes (16%), followed by Actinobacteria (13%). A greater microbial diversity was found in patients with moderate-to-severe disease, and alpha diversity showed a statistically significant decrease in patients with advanced disease when assessed by Shannon (ρ = 0.528; P = 0.029, Spearman correlation coefficient) and Chao1 (ρ = 0.53; P = 0.028, Spearman correlation coefficient) alpha-diversity indexes. The higher severity that characterizes advanced COPD is paralleled by a decrease in the diversity of the bronchial microbiome, with a loss of part of the resident flora that is replaced by a more restricted microbiota that includes PPMs
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
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