Two-Photon Absorption in a Conformationally Twisted D-π-A Oligomer : A Synergic Photosensitizing Approach for Multiphoton Lithography

International audienceA comparative study of the linear and nonlinear optical properties of a novel triphenylamine–pyrimidine alternated oligomer and its corresponding V-shaped quadrupolar monomer is presented. Both chromophores strikingly exhibit the same spectral shape when considering their respective one- and two-photon absorption spectra. This effect was attributed to a weak interchromophore coupling within the oligomer which exhibits a highly distorted geometry resulting in a strong reduction of the effective conjugation length. The recursive implementation of nine monomers into a three-dimensional architecture leads however to a cooperative enhancement of the two-photon absorption (2PA) cross-section with a δMAX of 5093 GM at 800 nm. This very high 2PA ability has been oriented to improve the two-photon induced polymerization efficiency of a bicomponent photoinitiator system implying a hexaarylbiimidazole used as a H-abstractor and an aliphatic amine used as a H-donor. The photosensitizing mechanism is investigated and we clearly show that the intrinsic photoinitiation efficiency of the oligomer is increased by a factor 3 as compared to its corresponding monomer. We therefore demonstrate that such a two-photon sensitizing strategy leads to a synergy effect combining a higher photoinitiation reactivity and a very large two-photon absorption cross-section

Tripodal molecules with triphenylamine core, diazine peripheral groups and extended π-conjugated linkers

International audienceA series of five octupolar molecules with central triphenylamine donor and peripheral diazine electron-withdrawing groups has been prepared. These structures possess extended π-spacer comprising multiple bonds in a combination with 1,4-phenylene and 2,5-thienylene subunits. Starting from tris(4-ethynylphenyl)amine, the key step in the preparation of the chromophores involves triple Sonogashira cross-coupling reaction. The photophysical properties of the compounds are described. A strong positive emission solvatochromism, typical for dyes featuring Intramolecular Charge Transfer (ICT), is observed, two-photon absorption (2PA) properties were also measured. Linear and nonlinear optical properties as well as electronic properties measured by cyclic voltametry and supported by DFT calculation were used to elucidate structure-property relationship

Synthesis, photophysics and nonlinear optical properties of stilbenoid pyrimidine-based dyes bearing methylenepyran donor groups.

International audienceThe nonlinear properties and the photophysical behavior of two π-conjugated chromophores that incorporate an electron-deficient pyrimidine core (A) and γ-methylenepyrans as terminal donor (D) groups have been thoroughly investigated. Both dipolar and quadrupolar branching strategies are explored and rationalized on the basis of the Frenkel exciton model. Even though a cooperative effect is clearly observed if the dimensionality is increased, the nonlinear optical (NLO) response of this series is moderate if one considers the nature of the D/A couple and the size of the chromophores (as measured by the number of π electrons). This effect was attributed to a disruption in the electronic conjugation within the dyes' scaffold for which the geometry deviates from planarity owing to a noticeable twisting of the pyranylidene end-groups. This latter structural parameter also has a strong influence on the excited-state dynamics, which leads to a very efficient fluorescence quenching

ANTARES: the first undersea neutrino telescope

The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given

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

Apport de l'échographie pour le diagnostic du reflux vésico-urétéral dans les infections urinaires de l'enfant

RENNES1-BU Santé (352382103) / SudocSudocFranceF

Evaluation d un indice non invasif de monitorage du remplissage au cours de la transplantation rénale (le pleth variability index)

La volémie joue un rôle central dans la reprise de fonction du greffon après transplantation rénale. L index de variabilité de la courbe de pléthysmographie (PVI), corrélé aux variations respiratoires de la pression artérielle pulsée, est un nouvel indice non invasif dynamique de prédiction de la réponse au remplissage vasculaire. L objectif de cette étude est d évaluer la capacité du PVI à prédire la réponse au remplissage au cours de la transplantation rénale. Après accord du comité de protection des personnes et consentement écrit, 19 patients ont été inclus et étudiés au cours de la transplantation rénale, sous anesthésie générale. Les paramètres hémodynamiques fournis par le Doppler œsophagien (volume d éjection systolique, VES) et le PVI ont été relevés avant et après une épreuve de remplissage de 250 ml de cristalloïdes. Les patients répondeurs au remplissage étaient définis par une augmentation du VES ( VES) d au moins 10%.Soixante-dix huit épreuves de remplissage ont été réalisées. Le PVI avant remplissage n était pas différent entre les cas répondeurs et les cas non répondeurs (11+-1 vs. 11+-2 respectivement, p=0,99). L aire sous la courbe ROC (Receiver Operating Characteristic) pour le PVI n est pas différente de 0,5 (p=0,34). Il n existait pas de corrélation significative entre le PVI et le VES (r=-0,04, p=0,70).Le PVI ne permet pas de prédire la réponse au remplissage au cours de la transplantation rénale. L optimisation hémodynamique dans ce cadre peut être guidée par le Doppler œsophagien.PARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocSudocFranceF

Reasons for rejecting hormonal contraception in Western countries: A systematic review

International audienceOver the past decade, women in Western countries have taken to various social media platforms to share their dissatisfactory experiences with hormonal contraception, which may be pills, patches, rings, injectables, implants or hormonal intrauterine devices (IUDs). These online testimonials have been denounced as spreading “hormonophobia”, i.e. an excessive fear of hormones based on irrational causes such as an overestimation of health risks associated with their use, that was already aroused by the recurring media controversies over hormonal contraception. In order to move toward a reproductive justice framework, we propose to study the arguments that women and men (as partners of female users) recently put forward against hormonal contraception to see whether they are related to hormonophobia. The aim of this article is to conduct a systematic review of the recent scientific literature in order to construct an evidence-based typology of reasons for rejecting hormonal contraception, in a continuum perspective from complaints to choosing not to use it, cited by women and men in Western countries in a recent time. The published literature was systematically searched using PubMed and the database from the French National Institute for Demographic Studies (Ined). A total of 42 articles were included for full-text analysis. Eight main categories emerged as reasons for rejecting hormonal contraception: problems related to physical side effects; altered mental health; negative impact on sexuality; concerns about future fertility; invocation of nature; concerns about menstruation; fears and anxiety; and the delegitimization of the side effects of hormonal contraceptives. Thus, arguments against hormonal contraception appeared complex and multifactorial. Future research should examine the provider-patient relationship, the gender bias of hormonal contraception and demands for naturalness in order to understand how birth control could better meet the needs and expectations of women and men in Western countries today

Why some women went off the pill: Adverse side-effects and claims of naturalness as reasons for rejecting hormonal contraception in Western countries

International audienc

Why some women went off the pill: Adverse side-effects and claims of naturalness as reasons for rejecting hormonal contraception in Western countries

International audienc