Adaptive downregulation of Cl- /HCO3 - exchange activity in rat hepatocytes under experimental obstructive cholestasis

In obstructive cholestasis, there is an integral adaptive response aimed to diminish the bile flow and minimize the injury of bile ducts caused by increased intraluminal pressure and harmful levels of bile salts and bilirrubin. Canalicular bicarbonate secretion, driven by the anion exchanger 2 (AE2), is an influential determinant of the canalicular bile salt-independent bile flow. In this work, we ascertained whether AE2 expression and/or activity is reduced in hepatocytes from rats with common bile duct ligation (BDL), as part of the adaptive response to cholestasis. After 4 days of BDL, we found that neither AE2 mRNA expression (measured by quantitative real-time PCR) nor total levels of AE2 protein (assessed by western blot) were modified in freshly isolated hepatocytes. However, BDL led to a decrease in the expression of AE2 protein in plasma membrane fraction as compared with SHAM control. Additionally, AE2 activity (J(OH)-, mmol/L/min), measured in primary cultured hepatocytes from BDL and SHAM rats, was decreased in the BDL group versus the control group (1.9 +/- 0.3 vs. 3.1 +/- 0.2, p<0.005). cAMP-stimulated AE2 activity, however, was not different between SHAM and BDL groups (3.7 +/- 0.3 vs. 3.5 +/- 0.3), suggesting that cAMP stimulated insertion into the canalicular membrane of AE2-containing intracellular vesicles, that had remained abnormally internalized after BDL. In conclusion, our results point to the existence of a novel adaptive mechanism in cholestasis aimed to reduce biliary pressure, in which AE2 internalization in hepatocytes might result in decreased canalicular HCO3- output and decreased bile flow.This work was supported by grants from Spanish Carlos III Health Institute (ISCIII) [J. M. Banales (FIS PI15/01132, PI18/01075 and Miguel Servet Program CON14/00129) cofinanced by "Fondo Europeo de Desarrollo Regional" (FEDER); "Instituto de Salud Carlos III" [CIBERehd: J. M. Banales], Spain; BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/BD to J. M. Banales), Department of Health of the Basque Country (J. M. Banales: 2017111010) and Euskadi RIS3 (J. M. Banales: 2016222001, 2017222014, 2018222029). "Fundacion Cientifica de la Asociacion Espanola Contra el Cancer" (AECC Scientific Foundation, to J. M. Banales). F. A. Crocenzi was recipient of a Young Investigator Scholarship from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Argentina. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Notulae to the Italian native vascular flora: 6

In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations and status changes to the Italian administrative regions for taxa in the genera Alchemilla, Arundo, Bupleurum, Clematis, Clinopodium, Cota, Crassula, Cytisus, Euphorbia, Hieracium, Isoëtes, Lamium, Leontodon, Linaria, Lychnis, Middendorfia, Ophrys, Philadelphus, Pinus, Sagina, Sedum, Taeniatherum, Tofieldia, Triticum, Veronica, and Vicia. Nomenclature and distribution updates, published elsewhere, and corrigenda are provided as supplementary material

Notulae to the Italian native vascular flora: 6

In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations and status changes to the Italian administrative regions for taxa in the genera Alchemilla, Arundo, Bupleurum, Clematis, Clinopodium, Cota, Crassula, Cytisus, Euphorbia, Hieracium, Isoëtes, Lamium, Leontodon, Linaria, Lychnis, Middendorfia, Ophrys, Philadelphus, Pinus, Sagina, Sedum, Taeniatherum, Tofieldia, Triticum, Veronica, and Vicia. Nomenclature and distribution updates, published elsewhere, and corrigenda are provided as supplementary material

Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

[no abstract available

Study of the doubly charmed tetraquark T+cc

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

On the synergistic corrosion inhibition and polymer healing effects of polyolefin coatings modified with Ce-loaded hydroxyapatite particles applied on steel

pH-sensitive hydroxyapatite particles were loaded with cerium ions (Ce-HAP) and incorporated into polyolefin coatings applied on carbon steel. The Ce-modified hydroxyapatite particles were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The protective performance of modified and reference polyolefin coatings applied on carbon steel was studied by electrochemical impedance spectroscopy (EIS), and the self-healing capability was evidenced by combining the scanning vibrating electrode technique (SVET) and pH micro-potentiometry with video-imaging, SEM and Raman. The modified coatings showed significantly improved long-term corrosion protection compared to reference coatings. The effect was attributed to the synergistic combination of the corrosion inhibition effect of cerium ions loaded in the HAP particles and polyolefin healing capability.This publication was made possible by NPRP11S-1226–170132 from Qatar National Research Fund (a member of the Qatar Foundation). The authors from Centro de Química Estrutural acknowledge the financial support of Fundação para a Ciência e Tecnologia (UIDB/00100/2020 and UIDP/00100/2020). Statements made herein are solely the responsibility of the authors. The authors acknowledge Dow Chemical Company (Dr. Bernhard Kainz, Global Application Development Leader Metal Packaging Coatings, Dow Coating Materials) for providing polyolefin CANVERA 1110 coating formulation; Voestalpine AG for providing carbon steel; Dr. Marta Alves (Instituto Superior Técnico) for conducting the XRD tests; Prof. Ana Clara Marques for valuable discussions; Mário Vale (Instituto Superior Técnico) for performing TG/DTG studies; Ana Mafalda Macatrão for helping with RAMAN characterization. Pedro Prazeres (PARALAB) for help with SEM visualization of self-healing; Mario Dias (LAIST, Técnico Lisboa) for determination of cerium, nitrate and total nitrogen contents in Ce-HAP particles.Scopu

Calcium carbonate particles loaded with triethanolamine and polyethylenimine for enhanced corrosion protection of epoxy coated steel

Calcium carbonate particles were synthesized and loaded with a mixture of two corrosion inhibitors, triethanolamine (TEA) and polyethylenimine (PEI). These particles can serve as pH-sensitive additives in epoxy coatings to provide "smarter" corrosion protection of carbon steel. Electrochemical impedance spectroscopy revealed that calcium carbonate particles loaded with the mixture of corrosion inhibitors improved corrosion resistance of coated panels and did not damage the barrier properties of the coating. Localized electrochemical studies of artificially damaged coatings on steel confirmed the corrosion inhibition effect.This publication was made possible by NPRP Grant NPRP-9-080-2-039 from Qatar National Research Fund (a member of the Qatar Foundation). L.M. Calado acknowledges Fundação para a Ciência e Tecnologia (FCT) for Ph.D. grant SFRH/BD/127341/2016. Authors from Portugal acknowledge FCT for the additional funding under the project UID/QUI/00100/2019; UIDB/00100/2020 and UIDP/00100/2020. Sherwin-Williams for providing the coating formulations; Voestalpine AG for providing carbon steel; Mario Vale for performing FTIR and TGA studies; Dr. Nick Laycock and Dr. Abitha Ramesh (Qatar Shell Research and Technology Centre) for the helpful technical guidance. Statements made herein are solely the responsibility of the authors.Scopu

Multimedialita' e nuove forme di didattica. Statistici ed esperti a confronto

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal