Structural role of PufX in the dimerization of the photosynthetic core complex of Rhodobacter sphaeroides.

Monomeric and dimeric PufX-containing core complexes have been purified from membranes of wild-type Rhodobacter sphaeroides. Reconstitution of both samples by detergent removal in the presence of lipids leads to the formation of two-dimensional crystals constituted of dimeric core complexes. Two-dimensional crystals were further analyzed by cryoelectron microscopy and atomic force microscopy. A projection map at 26-A resolution reveals that core complexes assemble in an "S"-shaped dimeric complex. Each core complex is composed of one reaction center, 12 light-harvesting 1 alpha/beta-heterodimers, and one PufX protein. The light-harvesting 1 assemblies are open with a gap of density of approximately 30-A width and surround oriented reaction centers. A maximum density is found at the dimer junction. Based on the projection map, a model is proposed, in which the two PufX proteins are located at the dimer junction, consistent with the finding of dimerization of monomeric core complexes upon reconstitution. This localization of PufX in the core complex implies that PufX is the structural key for the dimer complex formation rather than a channel-forming protein for the exchange of ubiquinone/ubiquinol between the reaction center and the cytochrome bc1 complex

Estudio de las necesidades recreacionales de los habitantes del cantón Milagro y su relación con el turismo en el año 2015.

La palabra recreación define a la acción y efecto de recrear. Por lo tanto, puede hacer referencia a crear o producir de nuevo algo. También se refiere a divertir, alegrar o deleitar, en una búsqueda de distracción en medio del trabajo y de las obligaciones cotidianas. El presente proyecto tiene como finalidad llegar a los centros turísticos de recreación para que puedan ofrecer a niños y adultos una opción de descanso, entretenimiento y diversión a través de las diferentes actividades turísticas que puedan ofrecer a los mismos. El descanso se le otorgo, tanto el sentido de compensación a la fatiga producto del trabajo, como el de la respuesta natural a las necesidades filosóficas del organismo que imponen a la necesidad de dormir. Se descansaba para poder recuperar y para compensar el agotamiento que produce el trabajo intelectual o las tensiones emocionales. El ser humano necesita tiempo de ocio o tiempo libre ya que es importante que se encuentre en óptimas condiciones físicas, emocionalmente y mentalmente para que realicen un mejor desempeño en los estudios como en lo laboral. En esta investigación se busca que los centros recreacionales dispongan de variedades actividades turísticas para que así, la demanda turística realice gasto por turismo interno el mismo que favorecerá a nuestra ciudad

Study of large hemispherical photomultiplier tubes for the ANTARES neutrino telescope

The ANTARES neutrino telescope, to be immersed depth in the Mediterranean Sea, will consist of a 3 dimensional matrix of 900 large area photomultiplier tubes housed in pressure resistant glass spheres. The selection of the optimal photomultiplier was a critical step for the project and required an intensive phase of tests and developments carried out in close collaboration with the main manufacturers worldwide. This paper provides an overview of the tests performed by the collaboration and describes in detail the features of the PMT chosen for ANTARES

Em torno da mesa do rei: artefatos, convivialidade e celebração no Rio de Janeiro joanino

Este artigo aborda um aspecto relevante do ritual das refeições na corte de D. João VI, no Rio de Janeiro: a prataria de mesa. Isto é, objetos de luxo destinados a servir e a consumir os alimentos. Com base em um inventário de bens de mesa enviados do Rio de Janeiro para Lisboa junto com o monarca em seu retorno a Portugal, em 1821, este artigo procura refletir sobre as funções e possíveis usos desses objetos, assim como sobre a importância desse universo material para o funcionamento, representação e celebração da Casa Real portuguesa na sua nova sede. O artigo argumenta que a presença e o uso de baixelas de prata de serviço, mas também de grande aparato, nas refeições públicas da família real pode contribuir para se repensar a imagem de uma corte pobre e sem brilho recorrentemente reforçada na historiografia do período joanino.This article discusses a specific issue of the royal dinner's rituals at the Court of Rio de Janeiro: the silver service: some luxury artifacts of different forms specially made to serve and consume food. Based on a inventory of these silver objects and also on a stock of table linen which were shipped to Lisbon, along with the royal family in 1821, The article intend to explore the functions and utilities of those objects at the table, as well as, analyze the importance of this material universe for the functioning, representation and celebration of the Portuguese Royal House in its new headquarters.The article argues that the use and even the exhibition of the banquet silver in public ceremonies may contribute to change a rather depreciative image of poverty the royal court in Brazil, which has being explored by the historiography for more than a hundred years

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

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 non–critically 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 (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free 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 support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (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 support–free 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

ATP synthesis by the F₀F₁-ATPase from the thermophilic Bacillus PS3 co-reconstituted with bacteriorhodopsin into liposomes:Evidence for stimulation of ATP synthesis by ATP bound to a noncatalytic binding site

F-type ATPase from the thermophilic Bacillus PS3, TF0F1, which was essentially free of bound nucleotides after isolation and purification, was co-reconstituted into liposomes with the light-driven proton pump bacteriorhodopsin. The time course of the light-induced ATP synthesis was biphasic; an initial slow phase accelerated to a final steady-state rate two to three times faster. Adding ATP before initiating the reaction suppressed the slow phase, suggesting that the state of occupancy of specific sites by ATP regulated the synthetic activity of TF0F1. Incubating the purified TF0F1 with ADP and ATP revealed one ADP and two ATP binding sites that were stable to gel filtration. We analyzed the time courses of light-induced ATP synthesis for the enzyme with different nucleotide content, after co-reconstitution into liposomes with bacteriorhodopsin. The two ATP sites were identified to have regulatory function. A complex containing TF0F1·ADP, 1:1, was co-reconstituted with various quantities of ATP to obtain a range of molar ratios of TF0F1·ADP:ATP of between 1:0 and 1:1.7. It was found that the initial rate of ATP synthesis increased with the level of ATP bound to the enzyme. After binding one ATP, a stimulation of ATP synthesis by a factor of 2 was observed. The second ATP site also exhibited regulatory properties. It stimulated ATP synthesis but to a much smaller extent; the stimulation did not exceed 20%. Binding of the photoreactive analogues 2-azido-[α-32P]ADP and 2-azido-[α-32P]ATP to the TF0F1 and their effects on the rate of ATP synthesis are described further. Importantly, after covalent labeling of the enzyme, tryptic digestion, and high performance liquid chromatography purification, the label was found associated with the βY364-containing tryptic peptide in all cases. βY364 is in the region of conserved residues GXEHYXXA, which is in the β subunit and known to be part of the noncatalytic site.</p

La conquête de Majorque par Jacques d'Aragon. Iconographie d'un plafond peint montpelliérain du XIIIe siècle

National audienceCette publication nous fait partager le mystère de la découverte d’une œuvre majeure, unique en Occitanie, un plafond peint conservé dans une maison de Montpellier inscrite au titre des Monuments historiques. Elle relate une épopée qui fait songer à celle de la tapisserie de la reine Mathilde.L’histoire est plus jeune de deux siècles et nous renvoie au 31 décembre 1229, à l’époque des rois d’Aragon et représente la prise de l’île de Majorque, épisode essentiel de la Reconquista de la péninsule Ibérique par Jacques d’Aragon (1208-1276), comte de Barcelone, seigneur de Montpellier. Il s’engage dans un vaste projet d’extension de son domaine en reprenant les royaumes occupés par les musulmans d’al-Andalus. Au cours de l’épopée, les seigneurs catalans, aragonais, languedociens, béarnais, provençaux, navarrais et français qui l’accompagnaient, trouvèrent leurs heures de gloire et de fortune.Ces peintures nous rappellent que Montpellier a appartenu successivement aux souverains aragonais puis majorquins entre 1204 et 1349. [Source éditeur

La conquête de Majorque par Jacques d'Aragon. Iconographie d'un plafond peint montpelliérain du XIIIe siècle

National audienceCette publication nous fait partager le mystère de la découverte d’une œuvre majeure, unique en Occitanie, un plafond peint conservé dans une maison de Montpellier inscrite au titre des Monuments historiques. Elle relate une épopée qui fait songer à celle de la tapisserie de la reine Mathilde.L’histoire est plus jeune de deux siècles et nous renvoie au 31 décembre 1229, à l’époque des rois d’Aragon et représente la prise de l’île de Majorque, épisode essentiel de la Reconquista de la péninsule Ibérique par Jacques d’Aragon (1208-1276), comte de Barcelone, seigneur de Montpellier. Il s’engage dans un vaste projet d’extension de son domaine en reprenant les royaumes occupés par les musulmans d’al-Andalus. Au cours de l’épopée, les seigneurs catalans, aragonais, languedociens, béarnais, provençaux, navarrais et français qui l’accompagnaient, trouvèrent leurs heures de gloire et de fortune.Ces peintures nous rappellent que Montpellier a appartenu successivement aux souverains aragonais puis majorquins entre 1204 et 1349. [Source éditeur