29 research outputs found
Juan Antonio Gonzålez Calderón, Académico del Derecho
This paper examines the induction of Argentine Professor Juan Antonio GonzaÌlez CalderoÌn to the National Academy of Law and Social Science of Buenos Aires in 1929. It discusses the academic work of Professor GonzaÌlez CalderoÌn prior to his induction to the aforementioned Academy (section II). It documents the process of his nomination, eligibility, review, voting, and the induction ceremony (section III). And it analyses the wealth of sources of law that the Argentine jurist used in his dissertation âThe necessary and permanent bases of the [Argentine] Constitutionâ delivered at the induction ceremony (section IV).Este trabajo examina la incorporacioÌn del Profesor Juan Antonio GonzaÌlez CalderoÌn a la Academia Nacional de Derecho y Ciencias Sociales de Buenos Aires en 1929. Para ello, aborda su labor acadeÌmica antes de su ingreso a esa Academia (II); documenta el proceso de incorporacioÌn a esa corporacioÌn (III); y analiza la riqueza de fuentes del derecho que el jurista argentino empleoÌ en su disertacioÌn âLas bases necesarias y permanentes de la ConstitucioÌnâ, pronunciada en la ceremonia de incorporacioÌn a esa Academia (IV).
Distinctive dielectric properties of nematic liquid crystal dimers
We provide an overview of the effect of the molecular structure on the dielectric properties of dimers exhibiting nematic and twist-bend nematic phases with special focus on how the conformational distribution changes are reflected by the dielectric behaviour. Nematic dimers show distinctive dielectric properties which differ from those of archetypical nematic liquid crystals, as for example, unusual temperature dependence of the static permittivity or dielectric spectra characterised by two low-frequency relaxation processes with correlated strengths. The interpretation of such characteristic behaviour requires that account is taken of the effect of molecular flexibility on the energetically favoured molecular shapes. The anisotropic nematic interactions greatly influence the conformational distribution. Dielectric behaviour can be used to track those conformational changes due to dependence of the averaged molecular dipole moment on the averaged molecular shape. Results for a number of dimers are compared and analysed on the basis of the influence of details of the molecular structure, using a recently developed theory for the dielectric properties of dimers.Postprint (author's final draft
Molecular dynamics of a binary mixture of twist-bend nematic liquid crystal dimers studied by dielectric spectroscopy
We report a comprehensive dielectric characterization of a liquid crystalline binary mixture composed of the symmetric mesogenic dimer CB7CB and the nonsymmetric mesogenic dimer FFO9OCB. In addition to the high-temperature nematic phase, such a binary mixture shows a twist-bend nematic phase at room temperature which readily vitrifies on slow cooling. Changes in the conformational distribution of the dimers are reflected in the dielectric permittivity and successfully analyzed by means of an appropriate theoretical model. It is shown that the dielectric spectra of the mixture reflect the different molecular dipole properties of the components, resembling in the present case the characteristic dielectric spectra of nonsymmetric dimers. Comparison of the nematic and twist-bend nematic phases reveals that molecular dynamics are similar despite the difference in the molecular environment.Postprint (author's final draft
Miscibility studies of two twist-bend nematic liquid crystal dimers with different average molecular curvatures. A comparison between experimental data and predictions of a Landau mean-field theory for the NTB-N phase transition
We report a calorimetric study of a series of mixtures of two twist-bend liquid crystal dimers, the 1'',7''-bis(4-cyanobiphenyl)-4'-yl heptane (CB7CB) and 1''-(2',4-difluorobiphenyl-4'-yloxy)-9''-(4-cyanobiphenyl-4'-yloxy) nonane (FFO9OCB), the molecules of which have different effective molecular curvatures. High-resolution heat capacity measurements in the vicinity of the NTB-N phase transition for a selected number of binary mixtures clearly indicate a first order NTB-N phase transition for all the investigated mixtures, the strength of which decreases when the nematic range increases. Published theories predict a second order NTB-N phase transition, but we have developed a self-consistent mean field Landau model using two key order parameters: A symmetric and traceless tensor for the orientational order and a short-range vector field which is orthogonal to the helix axis and rotates around of the heliconical structure with an extremely short periodicity. The theory, in its simplified form, depends on two effective elastic constants and explains satisfactorily our heat capacity measurements and also predicts a first-order NTB-N phase transition. In addition, as a complementary source of experimental measurements, the splay (K1) and bend (K3) elastic constants in the conventional nematic phase for the pure compounds and some selected mixtures have been determined.Postprint (author's final draft
Influence of internal flexibility on the double glass transition in a series of odd non-symmetric liquid crystal dimers characterised by dielectric measurements
Dielectric measurements (thermally stimulated depolarisation currents and broadband dielectric spectroscopy) have been performed near the glass transition to study the glass transition on the odd non-symmetric liquid crystal (LC) dimers of the series -(4-cyanobiphenyl-4'-oxy)--(1-pyreniminebenzylidene-4'-oxy) alkanes (CBOnO.Py) with n ranging from 3 to 9. A previous study [S. Diez-Berart et al., Materials 8 (2015) 3334] carried out in CBO11O.Py showed the presence of two glass transition temperatures, attributed to different molecular motions of the terminal groups. The study performed allows us to analyse the molecular dynamics in the rest of the series and determine the role played by the flexible spacer. Parallel and perpendicular orientations of the molecular director with regards to the probe electric field have been investigated. The low and intermediate observed relaxations are explained in the framework of Stocchero's theoretical model [M. Stocchero, J. Chem. Phys. 121 (2004) 8079] for the dielectric behaviour of non-symmetric LCs dimers, as independent end-over-end rotations of each terminal semi-rigid unit. As the length of the spacer chain in the series of compounds decreases, the different relaxations become progressively more coupled at the glass transition. Numerical simulations of the calorimetric response from the obtained kinetic parameters show good agreement with experimental behaviour.Postprint (author's final draft
Association of Candidate Gene Polymorphisms With Chronic Kidney Disease: Results of a Case-Control Analysis in the Nefrona Cohort
Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2, 445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionizationtime of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (nâ=â143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (nâ=â152), or no hydrocortisone (nâ=â108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (nâ=â137), shock-dependent (nâ=â146), and no (nâ=â101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions
Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41â6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000â2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2â79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999â2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Planning London's transport
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