Toxicity of CeO2 nanoparticles on a freshwater experimental trophic chain: A study in environmentally relevant conditions through the use of mesocosms

The toxicity of CeO2 NPs on an experimental freshwater ecosystem was studied in mesocosm, with a focus being placed on the higher trophic level, i.e. the carnivorous amphibian species Pleurodeles waltl. The system comprised species at three trophic levels: (i) bacteria, fungi and diatoms, (ii) Chironomus riparius larvae as primary consumers and (iii) Pleurodeles larvae as secondary consumers. NP contamination consisted of repeated additions of CeO2 NPs over 4 weeks, to obtain a final concentration of 1 mg/L. NPs were found to settle and accumulate in the sediment. No effects were observed on litter decomposition or associated fungal biomass. Changes in bacterial communities were observed from the third week of NP contamination. Morphological changes in CeO2 NPs were observed at the end of the experiment. No toxicity was recorded in chironomids, despite substantial NP accumulation (265.8±14.1mg Ce/kg). Mortality (35.3±6.8%) and a mean Ce concentration of 13.5±3.9mg/kg were reported for Pleurodeles. Parallel experiments were performed on Pleurodeles to determine toxicity pathways: no toxicity was observed by direct or dietary exposures, although Ce concentrations almost reached 100 mg/kg. In view of these results, various toxicity mechanisms are proposed and discussed. The toxicity observed on Pleurodeles in mesocosm may be indirect, due to microorganism’s interaction with CeO2 NPs, or NP dissolution could have occurred in mesocosm due to the structural complexity of the biological environment, resulting in toxicity to Pleurodeles. This study strongly supports the importance of ecotoxicological assessment of NPs under environmentally relevant conditions, using complex biological systems

Peritoneal Sclerosis in a Patient on Long-term Continuous Ambulatory Peritoneal Dialysis (CAPD). : An Autopsy Case.

若年性ネフロン癆による慢性腎不全でCAPD (continuous ambulatory peritoneal dialysis)導入し, 6年6ヵ月後に死亡した20歳男性の1剖検例を報告した。CAPD導入数カ月後, 腹膜炎による除水能低下を起こしたが, 約5ヵ月後に回復した。CAPD導入1年5ヵ月以降重症な腹膜炎罹患により除水能低下状態が遷延したが, 次第に回復した。しかし, 体液貯留傾向のため, 3年2ヵ月後より高張透析液を使用し除水量の増加を得たが, 3年9ヵ月後に不可逆的な除水能低下状態となった。一方, クレアチニンの透析排液/血漿濃度比(D/P)から見た溶質除去能は, その約半年後まで保たれており, 血清クレアチニン値の上昇は軽度であった。剖検にて腹膜の線維性肥厚と高度の内腔狭窄を伴う動静脈硬化を認め, 腹膜硬化症と診断した。本例の腹膜硬化症は, 頻回の腹膜炎と高張透析液の使用が主な原因と考えられた。腹膜機能を長期に維持するためには, 腹膜炎の予防と高張透析液の使用を最小限にすることが重要と考えられた。A 20-year-old man, treated with continuous ambulatory peritoneal dialysis (CAPD) for 6.5 years because of-end-stage renal disease due to juvenile nephronophthysis, died of ultrafiltration failure, and the morphological examination of peritoneum was carried out at autopsy. Nine episodes of peritonitis developed, and ultrafiltration transiently decreased after each episodes. At 2 years after the start of CAPD, severe peritonitis occurred, and then his body weight and blood pressure gradually increased. At 4 years after the beginning of CAPD, when hyperosmotic dialysate was frequently used, ultrafiltration was irreversively deteriorated. On the other hand, creatinine dialysate/plasma ratio remained within normal limits for about several months, and the increase in the level of serum creatinine was very little. The peritoneum obtained at autopsy revealed marked fibrous thickening as well as the conspicuous luminal narrowing of arteries and veins due to intimal thickening. The development of peritoneal sclerosis seemed to be related with the frequency and severity of peritonitis and the use of hyperosmotic dialysate

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Emulsions inverses cristallisables pour l'évolution dirigée

PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Synthesis, Characterisation and Reactions of Phosphine-Substituted Alkynylboronates and Alkynyltrifluoroborate Salts

The synthesis and structural characterisation of phosphine-substituted alkynylboronates is reported. A P(III)-centred alkynylboronate (2) was prepared that showed little evidence for the conjugation of the P-lone pair to the boron via the alkyne π-system, as judged by X-ray crystallography studies of 2 and a related P(V) compound, 3. In addition, corresponding alkynyltrifluoroborate salts were prepared that showed improved stability by comparison to their boronic ester counterparts. These salts undergo Pd-catalysed cross-coupling reactions with aryl halides

Lumière supercontinuum et plasmons de surface dans une valise !

International audienceCet article présente un montage optique compact et transportable illustrant la génération de supercontinuum dans une fibre optique suivie de l’excitation d’un plasmon de surface sur un film d’or. Mis sous la forme d’une valise pédagogique, ce montage est utilisé depuis 2015 (Année internationale de la lumière) comme support lors de visites de laboratoire ou d’expositions au grand public. Grâce à ses multiples facettes et sa richesse scientifique, il permet d’illustrer et d’expliquer de manière efficace et passionnante les phénomènes d’optique non linéaire et la physique des plasmons

Synthesis of new sulfated disaccharides for the modulation of TLR4-dependent inflammation

International audienceNatural sulfated glycans are key players in inflammation through TLR4 activation; therefore synthetic exogenous sulfated saccharides can be used to downregulate inflammation processes. We have designed and synthesized new sulfated compounds based on small and biocompatible carbohydrates that are able to cross the BBB. A suitable protected donor and acceptor, obtained from a unique precursor, have been stereoselectively glycosylated to give an orthogonally protected cellobiose disaccharide. Selective deprotection and sulfation allowed the syntheses of four differentially sulfated disaccharides, which have been characterized by NMR, HRMS and MS/MS. Together with their partially protected precursors, the new compounds were tested on HEK-TLR4 cells. Our results show the potential of small oligosaccharides to modulate TLR4 activity, confirming the need for sulfation and the key role of the 6-sulfate groups to trigger TLR4 signalization