444 research outputs found
Thallium under extreme compression
We present a combined theoretical and experimental study of the high-pressure
behavior of thallium. X-ray diffraction experiments have been carried out at
room temperature up to 125 GPa using diamond-anvil cells, nearly doubling the
pressure range of previous experiments. We have confirmed the hcp-fcc
transition at 3.5 GPa and determined that the fcc structure remains stable up
to the highest pressure attained in the experiments. In addition, HP-HT
experiments have been performed up to 8 GPa and 700 K by using a combination of
x-ray diffraction and a resistively heated diamond-anvil cell. Information on
the phase boundaries is obtained, as well as crystallographic information on
the HT bcc phase. The equation of state for different phases is reported. Ab
initio calculations have also been carried out considering several potential
high-pressure structures. They are consistent with the experimental results and
predict that, among the structures considered in the calculations, the fcc
structure of thallium is stable up to 4.3 TPa. Calculations also predict the
post-fcc phase to have a close-packed orthorhombic structure above 4.3 TPa.Comment: 29 pages, 14 figure
Analysis of Synaptic Proteins in the Cerebrospinal Fluid as a New Tool in the Study of Inborn Errors of Neurotransmission
Abstract In a few rare diseases, specialised studies in cerebrospinal fluid (CSF) are required to identify the underlying metabolic disorder. We aimed to explore the
possibility of detecting key synaptic proteins in the CSF, in particular dopaminergic and gabaergic, as new procedures
that could be useful for both pathophysiological and diagnostic purposes in investigation of inherited disorders
of neurotransmission. Dopamine receptor type 2 (D2R), dopamine transporter (DAT) and vesicular monoamine transporter type 2 (VMAT2) were analysed in CSF samplesfrom 30 healthy controls (11 days to 17 years) by western blot analysis. Because VMAT2 was the only protein with intracellular localisation, and in order to compare results, GABA vesicular transporter, which is another intracellular protein, was also studied. Spearmanâs correlation and
Studentâs t tests were applied to compare optical density signals between different proteins. All these synaptic proteins could be easily detected and quantified in the
CSF. DAT, D2R and GABA VT expression decrease with age, particularly in the first months of life, reflecting the expected intense synaptic activity and neuronal circuitry formation. A statistically significant relationship was found
between D2R and DAT expression, reinforcing the previous evidence of DAT regulation by D2R. To our knowledge, there are no previous studies on human CSF reporting a reliable
analysis of these proteins. These kinds of studies could help elucidate new causes of disturbed dopaminergic and gabaergic
transmission as well as understanding different responses to L-dopa in inherited disorders affecting dopamine metabolism.
Moreover, this approach to synaptic activity in vivo can be extended to different groups of proteins and diseases
Solidification of small para-H2 clusters at zero temperature
We have determined the ground-state energies of para-H clusters at zero
temperature using the diffusion Monte Carlo method. The liquid or solid
character of each cluster is investigated by restricting the phase through the
use of proper importance sampling. Our results show inhomogeneous
crystallization of clusters, with alternating behavior between liquid and solid
phases up to N=55. From there on, all clusters are solid. The ground-state
energies in the range N=13--75 are established and the stable phase of each
cluster is determined. In spite of the small differences observed between the
energy of liquid and solid clusters, the corresponding density profiles are
significantly different, feature that can help to solve ambiguities in the
determination of the specific phase of H clusters.Comment: 17 pages, accepted for publication in J. Phys. Chem.
Inhibition of HIV-1 Replication in Human Monocyte-Derived Macrophages by Parasite Trypanosoma cruzi
and HIV-1 to date.0.01). inhibits HIV-1 replication at several replication stages in macrophages, a major cell target for both pathogens
Usefulness of analysis of cerebrospinal fluid for the diagnosis of neurotransmitters and pterin defects and glucose and folate transport deficiencies across blood brain barrier
Med Clin (Barc). 2006 Jun 17;127(3):81-5.
[Usefulness of analysis of cerebrospinal fluid for the diagnosis of neurotransmitters and pterin defects and glucose and folate transport deficiencies across blood brain barrier]
[Article in Spanish]
Ormazabal A, GarcĂa Cazorla A, PĂ©rez Dueñas B, Pineda M, Ruiz A, LĂłpez Laso E, GarcĂa Silva M, Carilho I, Barbot C, Cormand B, Ribases M, Moller L, FernĂĄndez Alvarez E, Campistol J, Artuch R.
Hospital Sant Joan de Déu, Esplugues, Barcelona, España.
Abstract
BACKGROUND AND OBJECTIVE: In the last few years, it has been described inborn errors of neurotransmitter and pterin metabolism and defects in folate and glucose transport across blood brain barrier. All these defects are classified as rare diseases and needs cerebrospinal fluid (CSF) sample analysis for diagnosis. Our aim was to evaluate the results of the application of a CSF analysis protocol in a pediatric population from Spain and Portugal presenting with neurological disorders of unknown origin.
PATIENTS AND METHOD: We studied CSF samples from and 283 patients with neurological disorders of unknown origin and 127 controls. Neurotransmitters were analysed by HPLC with electrochemical detection, and pterins and 5-methyltetrahydrofolate were determined by HPLC with fluorescence detection.
RESULTS: We diagnosed 3 patients with tyrosine hidroxylase deficiency, 2 with dopa responsive dystonia, 14 with GTP-ciclohydrolase deficiency, 2 with glucose transport deficiency and 43 with cerebral folate deficiency.
CONCLUSIONS: This study allowed us to diagnose new patients, and more importantly, the establishment in all of them of a pharmacological or nutritional treatment. The most frequent defect found was CSF 5-methyltetrahydrofolate deficiency, which was present in different groups of patients.
PMID: 16827996 [PubMed - indexed for MEDLINE
Testing Reactive Probabilistic Processes
We define a testing equivalence in the spirit of De Nicola and Hennessy for
reactive probabilistic processes, i.e. for processes where the internal
nondeterminism is due to random behaviour. We characterize the testing
equivalence in terms of ready-traces. From the characterization it follows that
the equivalence is insensitive to the exact moment in time in which an internal
probabilistic choice occurs, which is inherent from the original testing
equivalence of De Nicola and Hennessy. We also show decidability of the testing
equivalence for finite systems for which the complete model may not be known
South American medicinal flora: a promising source of novel compounds with antiprotozoal activity
Native populations of South America have employed herb-based preparations for the treatment
of parasite diseases. In this review, some examples of South American medicinal plants from which
bioactive molecules have been isolated are presented. Results of our research related to the study of novel
compounds with antiprotozoal activity are also presented herein. Peruvin and psilostachyin, two sesquiterpene
lactones isolated from the Argentine medicinal species Ambrosia tenuifolia, presented significative in
vitro activity on Trypanosoma cruzi epimastigotes and trypomastigotes. Psilostachyin also presented in vivo
activity in T. cruzi infected mice. Both compounds were also active on Leishmania spp. The results obtained
suggest that psilostachyin could be considered a potential lead molecule in the development of novel
trypanocidal agents.Colegio de Farmacéuticos de la Provincia de Buenos Aire
The MEGARA view of outflows in LINERs
Outflows are believed to be ubiquitous in all AGNs, although their presence
in low luminosity AGNs, in particular, for LINERs, has only started to be
explored. Their properties (geometry, mass and energetics) are still far from
being properly characterised. We use integral field spectroscopic data from the
MEGARA instrument, at GTC, to analyse a small sample of nine LINERs, candidates
of hosting ionised gas outflows. We aim to study the main emission lines in the
optical to identify their properties and physical origin. We obtained data
cubes at the lowest (R6000) and highest (R20000) spectral
resolution of MEGARA. We modelled and subtracted the stellar continuum to
obtain the ionised gas contribution, and then fitted the emission lines to
extract their kinematics (velocity and velocity dispersion). We identified
outflows as a secondary component in the emission lines. The primary component
of the emission lines was typically associated to gas in the galactic disc. For
some objects, there is an enhanced- region co-spatial with the
secondary component. We associated it to turbulent gas produced due to the
interaction with the outflows. We find signatures of outflows in six LINERs,
with mass outflow rates ranging from 0.004 to 0.4 Myr and energy
rates from 10 to 10 erg s. Their mean
electronic density is 600cm, extending to distances of 400 pc at
an (absolute) velocity of 340 km s (on average). They tend to be
compact and unresolved, although for some sources they are extended with a
bubble-like morphology. Our results confirm the existence of outflows in the
best LINER candidates identified using previous long-slit spectroscopic and
imaging data. These outflows do not follow the scaling relations obtained for
more luminous AGNs. For some objects we discuss jets as the main drivers of the
outflowsComment: 31 pages, 15 figures. Accepted for publication in Astronomy &
Astrophysic
Utilization study in real clinical practice of ceftolozane/tazobactam vs aminoglycosides and/or colistin in the treatment of multirresistant or extremely resistant Pseudomonas aeruginosa
Introduction. Comparative âreal lifeâ data on the effectiveness and safety of ceftolozane/tazobactam (C/T) versus other regimens (aminoglycosides/colistin/combination), in the treatment of multi-resistant (MDR) and extremely resistant (XDR) Pseudomonas aeruginosa (PA), are needed to establish positions. Material and methods. Observational, retrospective study of patients with microbiological confirmation of MDR and XDR PA from July 2016 up to December 2018 in a tertiary hospital. Variables: age, sex, comorbidities, risk factors for multidrug resistance, variables related to infection, source of infection, microorganism and type of sample, antibiotic treatment, clinical cure, microbiological cure, recurrence, mortality on admission and 30 days post-discharge. Patients were classified according to received antibiotic treatment, C/T or aminoglycosides/colistin/combination Results. A total of 405 patients with PA MDR and XDR infection (73.1% men, mean age 63 ± 15 years) were studied. An 87.1% of PA XDR and a 12.9% MDR were observed. All patients received C/T as targeted therapy and in the amino-glycosides/colistin/combination group were 73.5%. Patients in the C/T group present worse prognostic factors: septic shock (30.0%) and catheterization (90.0%) (p<0.05). There were not statistically significant differences in microbiological cure (p=0.412), recurrence (p=0.880) and clinical cure (p=0.566). There were not statistically significant differences in mortality at admission (p=0.352) or at 30 days after discharge (p=0.231). A 17.2% of the patients with aminoglycosides/colistin/combination had acute kidney injury according to RIFLE criteria and 4.3% with C/T. Conclusions. The data obtained suggest that there have been no differences in effectiveness (clinical or microbiological cure) in favour of C/T, although, in the period studied, it was used in most cases in multitreated patients with a worse prognosis. Randomized and prospective studies would be needed to establish an adequate positioning. © The Author 2021
The pilot project of the mineral collections from the University of Barcelona: An opportunity to create updated teaching material to be shared with other universities
The Mineralogy teaching collection from the University of Barcelona has proved to be a successful tool for students. The urge of its renewal to meet the necessities of modernCindustry brought the idea to replicate this collection in order to offer high quality teaching material to other universities worldwide. This project has led to an international collaboration aiming to enhance international solidarity among universities and make evident the importance of Mineralogy in Geology studies
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