Palladium-catalysed direct regioselective C5-arylation of a thiophene bearing a cyclopropyl ketone group at C2

International audienceA thiophene bearing a cyclopropyl ketone group at C2 was successfully employed in palladium-catalysed direct arylation. The reaction proceeds regioselectively at C5 without decomposition of the cyclopropyl ketone substituent. These couplings were performed employing as little as 0.5 mol% of ligand-free Pd(OAc)2 catalyst with electron-deficient aryl bromides. A wide variety of functional groups on the aryl bromide such as nitrile, nitro, acetyl, formyl, benzoyl, ester, trifluoromethyl, fluoro or methoxy was tolerated. © 2013 Elsevier Science. All rights reserved

Unveiling the hidden universe with JWST: The contribution of dust-obscured galaxies to the stellar mass function at z∼3−8\mathbf{z\sim3-8}

The emergence of massive, optically-faint galaxies in infrared observations has revealed that our view of the high-redshift Universe was previously incomplete. With the advent of JWST, we can for the first time probe the rest-frame optical emission of galaxies at $z>3$ with high sensitivity and spatial resolution, thus moving towards a more complete census of the galaxy population at high redshifts. To this end, we present a sample of 148 massive, dusty galaxies from the JWST/CEERS survey, colour-selected using solely JWST bands. With deep JWST/NIRCam data from 1.15$\mu$m to 4.44$\mu$m and ancillary HST/ACS and WFC3 data, we determine the physical properties of our sample using spectral energy distribution fitting with BAGPIPES. We demonstrate that our selection method efficiently identifies massive ($\mathrm{\langle \log M_\star/M_\odot \rangle \sim 10}$) and dusty ($\mathrm{\langle A_V\rangle \sim 2.7\ mag}$) sources, with a majority at $z>3$ and predominantly lying on the galaxy main-sequence. The main results of this work are the stellar mass functions (SMF) of red, optically-faint galaxies from redshifts between $3<z<8$: these galaxies make up a significant fraction of the pre-JWST total SMF at $3<z<4$, and dominate the high-mass end of the pre-JWST SMF at $4<z<6$ and $6<z<8$, suggesting that our census of the galaxy population needs amendment at these epochs. While larger areas need to be surveyed in the future, our results suggest already that the integrated stellar mass density at $\mathrm{\log M_\star/M_\odot>9.25}$ may have been underestimated by $\sim$20-25% at $z\sim3-6$, and $\sim$110% at $z\sim6-8$.Comment: 19 pages, 10 figures, submitted to MNRA

Ventilation and outcomes following robotic-assisted abdominal surgery: an international, multicentre observational study

Background: International data on the epidemiology, ventilation practice, and outcomes in patients undergoing abdominal robotic-assisted surgery (RAS) are lacking. The aim of the study was to assess the incidence of postoperative pulmonary complications (PPCs), and to describe ventilator management after abdominal RAS. Methods: This was an international, multicentre, prospective study in 34 centres in nine countries. Patients ≥18 yr of age undergoing abdominal RAS were enrolled between April 2017 and March 2019. The Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score was used to stratify for higher risk of PPCs (≥26). The primary outcome was the incidence of PPCs. Secondary endpoints included the preoperative risk for PPCs and ventilator management. Results: Of 1167 subjects screened, 905 abdominal RAS patients were included. Overall, 590 (65.2%) patients were at increased risk for PPCs. Meanwhile, 172 (19%) patients sustained PPCs, which occurred more frequently in 132 (22.4%) patients at increased risk, compared with 40 (12.7%) patients at lower risk of PPCs (absolute risk difference: 12.2% [95% confidence intervals (CI), 6.8–17.6%]; P&lt;0.001). Plateau and driving pressures were higher in patients at increased risk, compared with patients at low risk of PPCs, but no ventilatory variables were independently associated with increased occurrence of PPCs. Development of PPCs was associated with a longer hospital stay. Conclusions: One in five patients developed one or more PPCs (chiefly unplanned oxygen requirement), which was associated with a longer hospital stay. No ventilatory variables were independently associated with PPCs. Clinical trial registration: NCT02989415

Unveiling the nature of infrared bright, optically dark galaxies with early JWST data

Over the last few years, both Atacama Large Millimeter/submillimeter Array (ALMA) and Spitzer observations have revealed a population of likely massive galaxies at z > 3 that was too faint to be detected in Hubble Space Telescope (HST) rest-frame ultraviolet imaging. However, due to the very limited photometry for individual galaxies, the true nature of these so-called HSTdark galaxies has remained elusive. Here, we present the first sample of such galaxies observed with very deep, high-resolution NIRCam imaging from the Early Release Science programme CEERS. 30 HST-dark sources are selected based on their red colours across 1.6–4.4 μm. Their physical properties are derived from 12-band multiwavelength photometry, including ancillary HST imaging. We find that these galaxies are generally heavily dust-obscured (AV ∼ 2 mag), massive (log (M/M☉) ∼ 10), star-forming sources at z ∼ 2-8 with an observed surface density of ∼0.8 arcmin-2. This suggests that an important fraction of massive galaxies may have been missing from our cosmic census at z > 3 all the way into the Epoch of Reionization. The HST-dark sources lie on the main sequence of galaxies and add an obscured star formation rate density of 3.2+1.8-1.3 × 10-3 M☉ yr-1 Mpc-3 at z ∼ 7, showing likely presence of dust in the Epoch of Reionization. Our analysis shows the unique power of JWST to reveal this previously missing galaxy population and to provide a more complete census of galaxies at z = 2-8 based on rest-frame optical imaging

A systematic review and consensus definitions for standardised end-points in perioperative medicine: pulmonary complications

BackgroundThere is a need for robust, clearly defined, patient-relevant outcome measures for use in randomised trials in perioperative medicine. Our objective was to establish standard outcome measures for postoperative pulmonary complications research

Palladium-catalyzed C4 direct arylation of 2,5-disubstituted furans with aryl bromides

International audienc

Palladium-catalysed C3 or C4 direct arylation of heteroaromatics via a C-H bond activation using aryl halides

International audienceIn recent years, palladium-catalyzed direct C2 or C5 arylation of heteroaromatic compounds with aryl halides by C[BOND]H bond activation has become a popular method for generating carbon-carbon bonds. For this reaction, a wide variety of heteroaromatics, such as furans, thiophenes, pyrroles, thiazoles, oxazoles, imidazoles, pyrazoles, indoles, triazoles, or even pyridines, can be employed. C3 and C4 arylations of heteroaromatics by C[BOND]H bond activation have also been described. Such reactions initially attracted much less attention than the C2 or C5 arylations due to the lower reactivity of the C3 and C4 positions. How- ever, in more recent years, several results from using modified and improved catalysts and reaction conditions have been reported, which permit C3 and C4 arylations in synthetically useful yields. Several intramolecular cyclizations of 2-substituted heterocycles have been described, with formation of a C[BOND]C bond on C3 resulting in the formation of five- to nine-membered rings incorporating pyrroles, indoles, thiophenes, furans, isoxazoles, or pyridines. Intermolecular C3 or C4 direct arylations are still quite rare for some heteroaromatics and are in several cases not highly regioselective. For such reactions, the best results have been obtained using pyrroles, thiophenes, or furans. For selected substrates, regioselective arylation at C3 or C4 of the heteroaromatic compounds took place under appropriate reaction conditions. Only a few examples of intermolecular couplings using oxazoles, thiazoles, imidazoles, isoxazoles, pyrazoles, triazoles, or pyridines have been reported. For most of these reactions, aryl iodides or bromides have been used as coupling partners, although a few examples with aryl chlorides are also known. This method allows the synthesis of complex molecules in only a few steps, and will provide access to a very wide variety of new heteroaryl derivatives in the next years