917 research outputs found
Chemical modeling for pH prediction of acidified musts with gypsum and tartaric acid in warm regions
Winemaking of musts acidified with up to 3 g/L of gypsum (CaSO4 2H2O) and tartaric acid, both individually and in combination, as well as a chemical modeling have been carried out to study the behaviour of these compounds as acidifiers. Prior to fermentation gypsum and tartaric acid reduce the pH by 0.12 and 0.17 pH units/g/L, respectively, but while gypsum does not increase the total acidity and reduces buffering power, tartaric acid shows the opposite behaviour. When these compounds were used in combination, the doses of tartaric acid necessary to reach a suitable pH were reduced. Calcium concentrations increase considerably in gypsum-acidified must, although they fell markedly after fermentation over time. Sulfate concentrations also increased, although with doses of 2 g/L they were lower than the maximum permitted level (2.5 g/L). Chemical modeling gave good results and the errors in pH predictions were less than 5% in almost all case
Isolation and characterization of few-layer black phosphorus
Isolation and characterization of mechanically exfoliated black phosphorus
flakes with a thickness down to two single-layers is presented. A modification
of the mechanical exfoliation method, which provides higher yield of atomically
thin flakes than conventional mechanical exfoliation, has been developed. We
present general guidelines to determine the number of layers using optical
microscopy, Raman spectroscopy and transmission electron microscopy in a fast
and reliable way. Moreover, we demonstrate that the exfoliated flakes are
highly crystalline and that they are stable even in free-standing form through
Raman spectroscopy and transmission electron microscopy measurements. A strong
thickness dependence of the band structure is found by density functional
theory calculations. The exciton binding energy, within an effective mass
approximation, is also calculated for different number of layers. Our
computational results for the optical gap are consistent with preliminary
photoluminescence results on thin flakes. Finally, we study the environmental
stability of black phosphorus flakes finding that the flakes are very
hydrophilic and that long term exposure to air moisture etches black phosphorus
away. Nonetheless, we demonstrate that the aging of the flakes is slow enough
to allow fabrication of field-effect transistors with strong ambipolar
behavior. Density functional theory calculations also give us insight into the
water-induced changes of the structural and electronic properties of black
phosphorus.Comment: 11 main figures, 7 supporting figure
Activation of amino acid metabolic program in cardiac HIF1-alpha-deficient mice.
HIF1-alpha expression defines metabolic compartments in the developing heart, promoting glycolytic program in the compact myocardium and mitochondrial enrichment in the trabeculae. Nonetheless, its role in cardiogenesis is debated. To assess the importance of HIF1-alpha during heart development and the influence of glycolysis in ventricular chamber formation, herein we generated conditional knockout models of Hif1a in Nkx2.5 cardiac progenitors and cardiomyocytes. Deletion of Hif1a impairs embryonic glycolysis without influencing cardiomyocyte proliferation and results in increased mitochondrial number and transient activation of amino acid catabolism together with HIF2α and ATF4 upregulation by E12.5. Hif1a mutants display normal fatty acid oxidation program and do not show cardiac dysfunction in the adulthood. Our results demonstrate that cardiac HIF1 signaling and glycolysis are dispensable for mouse heart development and reveal the metabolic flexibility of the embryonic myocardium to consume amino acids, raising the potential use of alternative metabolic substrates as therapeutic interventions during ischemic events.This project has been supported by FundaciĂłn Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Spain and by grants to S.M.-P. from the European Research Council, European Union, FP7-PEOPLE-2010-RG_276891; FundaciĂłn TV3 La MaratĂł, Spain, 201507.30.31; Comunidad de Madrid (CAM); Spain and European Union (EU), B2017/BMD-3875; Instituto de Salud Carlos III, Spain, PI17/01817; Universidad Francisco de Vitoria (UFV), Spain and LeDucq Foundation, France, 17CVD04. I.M.-M. was supported by La Caixa-CNIC and Fundacion Alfonso MartĂn Escudero fellowships, Spain. T.A.-G. was supported by a predoctoral award granted by CAM/EU and UFV, Spain, PEJD-2018-PRE/SAL-9529 and SM-P by a Contrato de Investigadores Miguel Servet (CPII16/00050) and UFV, Spain.S
Functional characterization of E- and P-cadherin in invasive breast cancer cells
Background: Alterations in the cadherin-catenin adhesion complexes are involved in tumor initiation, progression and metastasis. However, the functional implication of distinct cadherin types in breast cancer biology is still poorly understood. Methods: To compare the functional role of E-cadherin and P-cadherin in invasive breast cancer, we stably transfected these molecules into the MDA-MB-231 cell line, and investigated their effects on motility, invasion and gene expression regulation. Results: Expression of either E-and P-cadherin significantly increased cell aggregation and induced a switch from fibroblastic to epithelial morphology. Although expression of these cadherins did not completely reverse the mesenchymal phenotype of MDA-MB-231 cells, both E-and P-cadherin decreased fibroblast-like migration and invasion through extracellular matrix in a similar way. Moreover, microarray gene expression analysis of MDA-MB-231 cells after expression of E-and P-cadherins revealed that these molecules can activate signaling pathways leading to significant changes in gene expression. Although the expression patterns induced by E-and P-cadherin showed more similarities than differences, 40 genes were differentially modified by the expression of either cadherin type. Conclusion: E-and P-cadherin have similar functional consequences on the phenotype and invasive behavior of MDA-MB-231 cells. Moreover, we demonstrate for the first time that these cadherins can induce both common and specific gene expression programs on invasive breast cancer cells. Importantly, these identified genes are potential targets for future studies on the functional consequences of altered cadherin expression in human breast cancer
Entanglement of single-photons and chiral phonons in atomically thin WSe
Quantum entanglement is a fundamental phenomenon which, on the one hand,
reveals deep connections between quantum mechanics, gravity and the space-time;
on the other hand, has practical applications as a key resource in quantum
information processing. While it is routinely achieved in photon-atom
ensembles, entanglement involving the solid-state or macroscopic objects
remains challenging albeit promising for both fundamental physics and
technological applications. Here, we report entanglement between collective,
chiral vibrations in two-dimensional (2D) WSe host --- chiral phonons (CPs)
--- and single-photons emitted from quantum dots (QDs) present in it. CPs which
carry angular momentum were recently observed in WSe and are a
distinguishing feature of the underlying honeycomb lattice. The entanglement
results from a "which-way" scattering process, involving an optical excitation
in a QD and doubly-degenerate CPs, which takes place via two indistinguishable
paths. Our unveiling of entanglement involving a macroscopic, collective
excitation together with strong interaction between CPs and QDs in 2D materials
opens up ways for phonon-driven entanglement of QDs and engineering chiral or
non-reciprocal interactions at the single-photon level
The Use of Virtual Reality Facilitates Dialectical Behavior TherapyÂź âObserving Sounds and Visualsâ Mindfulness Skills Training Exercises for a Latino Patient with Severe Burns: A Case Study
Sustaining a burn injury increases an individual's risk of developing psychological problems such as generalized anxiety, negative emotions, depression, acute stress disorder, or post-traumatic stress disorder. Despite the growing use of Dialectical Behavioral TherapyÂź (DBTÂź) by clinical psychologists, to date, there are no published studies using standard DBTÂź or DBTÂź skills learning for severe burn patients. The current study explored the feasibility and clinical potential of using Immersive Virtual Reality (VR) enhanced DBTÂź mindfulness skills training to reduce negative emotions and increase positive emotions of a patient with severe burn injuries. The participant was a hospitalized (in house) 21-year-old Spanish speaking Latino male patient being treated for a large (>35% TBSA) severe flame burn injury.Methods: The patient looked into a pair of Oculus Rift DK2 virtual reality goggles to perceive the computer-generated virtual reality illusion of floating down a river, with rocks, boulders, trees, mountains, and clouds, while listening to DBTÂź mindfulness training audios during 4 VR sessions over a 1 month period. Study measures were administered before and after each VR session.Results: As predicted, the patient reported increased positive emotions and decreased negative emotions. The patient also accepted the VR mindfulness treatment technique. He reported the sessions helped him become more comfortable with his emotions and he wanted to keep using mindfulness after returning home.Conclusions: Dialectical Behavioral Therapy is an empirically validated treatment approach that has proved effective with non-burn patient populations for treating many of the psychological problems experienced by severe burn patients. The current case study explored for the first time, the use of immersive virtual reality enhanced DBTÂź mindfulness skills training with a burn patient. The patient reported reductions in negative emotions and increases in positive emotions, after VR DBTÂź mindfulness skills training. Immersive Virtual Reality is becoming widely available to mainstream consumers, and thus has the potential to make this treatment available to a much wider number of patient populations, including severe burn patients. Additional development, and controlled studies are needed
Taxonomic variations in the gut microbiome of gout patients with and without tophi might have a functional impact on urate metabolism
Objective: To evaluate the taxonomic composition of the gut microbiome in gout patients with and without tophi
formation, and predict bacterial functions that might have an impact on urate metabolism.
Methods: Hypervariable V3âV4 regions of the bacterial 16S rRNA gene from fecal samples of gout patients with
and without tophi (n=33 and n=25, respectively) were sequenced and compared to fecal samples from 53 healthy
controls. We explored predictive functional profles using bioinformatics in order to identify diferences in taxonomy
and metabolic pathways.
Results: We identifed a microbiome characterized by the lowest richness and a higher abundance of Phascolarctobacterium, Bacteroides, Akkermansia, and Ruminococcus_gnavus_group genera in patients with gout without tophi
when compared to controls. The Proteobacteria phylum and the Escherichia-Shigella genus were more abundant
in patients with tophaceous gout than in controls. Fold change analysis detected nine genera enriched in healthy
controls compared to gout groups (Bifdobacterium, Butyricicoccus, Oscillobacter, Ruminococcaceae_UCG_010, Lachnospiraceae_ND2007_group, Haemophilus, Ruminococcus_1, Clostridium_sensu_stricto_1, and Ruminococcaceae_
UGC_013). We found that the core microbiota of both gout groups shared Bacteroides caccae, Bacteroides stercoris ATCC
43183, and Bacteroides coprocola DSM 17136. These bacteria might perform functions linked to one-carbon metaboâ
lism, nucleotide binding, amino acid biosynthesis, and purine biosynthesis. Finally, we observed diferences in key
bacterial enzymes involved in urate synthesis, degradation, and elimination.
Conclusion: Our fndings revealed that taxonomic variations in the gut microbiome of gout patients with and withâ
out tophi might have a functional impact on urate metabolism.
Keywords: Gout, Gut microbiota, Uric acid metabolis
Identification of lptA, lpxE, and lpxO, Three Genes Involved in the Remodeling of Brucella Cell Envelope.
The brucellae are facultative intracellular bacteria that cause a worldwide extended zoonosis. One of the pathogenicity mechanisms of these bacteria is their ability to avoid rapid recognition by innate immunity because of a reduction of the pathogen-associated molecular pattern (PAMP) of the lipopolysaccharide (LPS), free-lipids, and other envelope molecules. We investigated the Brucella homologs of lptA, lpxE, and lpxO, three genes that in some pathogens encode enzymes that mask the LPS PAMP by upsetting the core-lipid A charge/hydrophobic balance. Brucella lptA, which encodes a putative ethanolamine transferase, carries a frame-shift in B. abortus but not in other Brucella spp. and phylogenetic neighbors like the opportunistic pathogen Ochrobactrum anthropi. Consistent with the genomic evidence, a B. melitensis lptA mutant lacked lipid A-linked ethanolamine and displayed increased sensitivity to polymyxin B (a surrogate of innate immunity bactericidal peptides), while B. abortus carrying B. melitensis lptA displayed increased resistance. Brucella lpxE encodes a putative phosphatase acting on lipid A or on a free-lipid that is highly conserved in all brucellae and O. anthropi. Although we found no evidence of lipid A dephosphorylation, a B. abortus lpxE mutant showed increased polymyxin B sensitivity, suggesting the existence of a hitherto unidentified free-lipid involved in bactericidal peptide resistance. Gene lpxO putatively encoding an acyl hydroxylase carries a frame-shift in all brucellae except B. microti and is intact in O. anthropi. Free-lipid analysis revealed that lpxO corresponded to olsC, the gene coding for the ornithine lipid (OL) acyl hydroxylase active in O. anthropi and B. microti, while B. abortus carrying the olsC of O. anthropi and B. microti synthesized hydroxylated OLs. Interestingly, mutants in lptA, lpxE, or olsC were not attenuated in dendritic cells or mice. This lack of an obvious effect on virulence together with the presence of the intact homolog genes in O. anthropi and B. microti but not in other brucellae suggests that LptA, LpxE, or OL ÎČ-hydroxylase do not significantly alter the PAMP properties of Brucella LPS and free-lipids and are therefore not positively selected during the adaptation to intracellular life
Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP
An experimental study of the normalized three-jet rate of b quark events with
respect to light quarks events (light= \ell \equiv u,d,s) has been performed
using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by
the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are
found to agree with theoretical predictions treating mass corrections at
next-to-leading order. Measurements of the b quark mass have also been
performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data
are found to be better described when using the running mass. The measurement
yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12
(theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise
measurement of the b mass derived from a high energy process. When compared to
other b mass determinations by experiments at lower energy scales, this value
agrees with the prediction of Quantum Chromodynamics for the energy evolution
of the running mass. The mass measurement is equivalent to a test of the
flavour independence of the strong coupling constant with an accuracy of 7
permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.
Search for CP violation in decays
A model-independent search for direct CP violation in the Cabibbo suppressed
decay in a sample of approximately 370,000 decays is
carried out. The data were collected by the LHCb experiment in 2010 and
correspond to an integrated luminosity of 35 pb. The normalized Dalitz
plot distributions for and are compared using four different
binning schemes that are sensitive to different manifestations of CP violation.
No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.
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