The induction of cytochrome P450 1A was studied in gudgeon (Gobio gobio), a common European cyprinid, using both farm-raised and field-caught fish. The effects of sex, reproductive status and past ...exposure to xenobiotics were assessed. When exposed to beta-naphthoflavone (bNF), reared gudgeon showed a dose-dependent increase of EROD activity with a plateau observed at doses from 20 mg/kg (females) and 5 mg/kg (males). The sexual difference in EROD activity was related to the gonadosomatic index (GSI) of the female whatever the level of induction. Dose and sex effects were confirmed by the immunodetection of CYP1A protein. More than one month was necessary for EROD activity to decrease to baseline levels. A second bNF injection after 32 days gave similar levels of induction, suggesting that EROD induction by bNF was not impaired by a pre-treatment. Wild fish were brought from two sites in the Rhône river basin: a low contaminated site (Ain) and a highly contaminated site (Rhône). Wild gudgeon were highly induced by bNF in laboratory, except males from the Rhône site which exhibited EROD levels as high as the EROD plateau found in laboratory conditions. A 2-month depuration period in clean water was necessary for EROD activity in wild gudgeon to decrease to baseline levels. These results provide better knowledge on the main factors of modulation of the induction in gudgeon as well as on the influence of the history of exposure to inducers.
Nous avons choisi d'étudier en laboratoire, sur le goujon, l'influence des facteurs : dose d'inducteur, maturité sexuelle et exposition préalable du poisson à des inducteurs. Ces expériences de laboratoire ont permis d'estimer la plage de variation de l'induction de l'EROD pour le goujon dans le cas de l'induction par la bNF. Avec cette espèce, l'influence de la maturité sexuelle des femelles a été confirmée et quantifiée. Nos résultats montrent que la rémanence de l'induction par la bNF (inducteur modèle) est de l'ordre du mois tandis que la rémanence de l'induction dans le site de Serrières est de l'ordre du double. Nous avons montré que la pré-induction, qu'elle soit artificielle ou " naturelle " (terrain), ne remet pas en cause l'inductibilité des poissons. Ces résultats ont ainsi un intérêt opérationnel car ils montrent que les activités EROD mesurées sur le terrain, dans une gamme de variation, sont directement liées à l'exposition récente du poisson sans influence des expositions passées.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The transcriptomic profile in a biofilm model of ribotypes (RT) 001 and 027 associated with recurrent Clostridioides difficile infection (R-CDI) and not associated with recurrent (NR)-CDI was ...analyzed to identify genes that may favor the recurrence. Twenty strains were selected, 10 RT001 and 10 RT027. From each ribotype, 5 were R-CDI and 5 NR-CDI. Biofilm and nonadherent cells were prepared from each clinical isolate, and the RNA was extracted. RNA samples were pooled in 8 combinations implying ribotype, recurrence, and biofilm formation. Each pool was separately labeled with Cy3 dye and hybridized on a microarray designed for this study. Slides were scanned, analyzed, and gene expression was compared between unique and grouped pools using the Student's t-test with Benjamini-Hochberg correction when appropriate. Validation was carried out by qRT-PCR for selected genes. Results: After comparisons of differentially expressed genes from both ribotypes of R-CDI strains (nonadherent cells vs. biofilm) and both ribotypes in biofilm (R-CDI vs. NR-CDI), we found 3 genes over-expressed and 1 under-expressed in common (adj. p ≤ 0.05). Overexpressed genes were CAJ70148 (a putative dehydrogenase), CAJ68100 (a secretion type II system protein from the GspH (pseudopilins) family), and CAJ69725 (a putative membrane protein); under-expressed was CAJ68151 (a segregation and condensation protein A). Because CAJ70148, CAJ68100, CAJ69725 and CAJ68151 were differentially expressed in biofilm in strains associated with R-CDI, they may support the biofilm favoring the recurrence of CDI. However, further studies will be needed for poorly studied genes.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report on microwave operation of top-gated single carbon nanotube transistors. From transmission measurements in the 0.1–1.6 GHz range we deduce device transconductance gm and gatenanotube ...capacitance Cg of micro- and nanometric devices. A large and frequency-independent gm ∼ 20 µS is observed on short devices which meets best dc results. The capacitance per unit gatelength ∼ 60 aF/µm is typical of top gates on conventional oxide with ǫ ∼ 10. This value is a factor 3–5 below the nanotube quantum capacitance which, according to recent simulations, favors high transit frequencies fT = gm/2πCg. For our smallest devices, we find a large fT ∼ 50 GHz with no evidence of saturation in length dependence
We report on shot noise measurements in carbon nanotube based Fabry-Perot electronic interferometers. As a consequence of quantum interferences, the noise power spectral density oscillates as a ...function of the voltage applied to the gate electrode. The quantum shot noise theory accounts for the data quantitatively. It allows to confirm the existence of two nearly degenerate orbitals. At resonance, the transmission of the nanotube approaches unity, and the nanotube becomes noiseless, as observed in quantum point contacts. In this weak backscattering regime, the dependence of the noise on the backscattering current is found weaker than expected, pointing either to electron-electron interactions or to weak decoherence.
The cosmic microwave background (CMB), a remnant of the Big Bang, provides unparalleled insights into the primordial universe, its energy content, and the origin of cosmic structures. The success of ...forthcoming terrestrial and space experiments hinges on meticulously calibrated data. Specifically, the ability to achieve an absolute calibration of the polarization angles with a precision of < 0.1 deg is crucial to identify the signatures of primordial gravitational waves and cosmic birefringence within the CMB polarization. We introduce the COSMOCal project, designed to deploy a polarized source in space for calibrating microwave frequency observations. The project aims to integrate microwave polarization observations from small and large telescopes, ground-based and in space, into a unified scale, enhancing the effectiveness of each observatory and allowing robust combination of data. To demonstrate the feasibility and confirm the observational approach of our project, we developed a prototype instrument that operates in the atmospheric window centered at 260 GHz, specifically tailored for use with the NIKA2 camera at the IRAM 30 m telescope. We present the instrument components and their laboratory characterization. The results of tests performed with the fully assembled prototype using a KIDs-based instrument, similar concept of NIKA2, are also reported. This study paves the way for an observing campaign using the IRAM 30m telescope and contributes to the development of a space-based instrument.
The Cosmic Microwave Background (CMB) radiation offers a unique window into the early Universe, facilitating precise examinations of fundamental cosmological theories. However, the quest for ...detecting B-modes in the CMB, predicted by theoretical models of inflation, faces substantial challenges in terms of calibration and foreground modeling. The COSMOCal (COsmic Survey of Millimeter wavelengths Objects for CMB experiments Calibration) project aims at enhancing the accuracy of the absolute calibration of the polarization angle \(\psi\) of current and future CMB experiments. The concept includes the build of a very well known artificial source emitting in the frequency range 20-350 GHz that would act as an absolute calibrator for several polarization facilities on Earth. A feasibility study to place the artificial source in geostationary orbit, in the far field for all the telescopes on Earth, is ongoing. In the meanwhile ongoing hardware work is dedicated to build a prototype to test the technology, the precision and the stability of the polarization recovering in the 1 mm band (220-300 GHz). High-resolution experiments as the NIKA2 camera at the IRAM 30m telescope will be deployed for such use. Once carefully calibrated (\(\Delta\psi\) < 0.1 degrees) it will be used to observe astrophysical sources such as the Crab nebula, which is the best candidate in the sky for the absolute calibration of CMB experiments.
Current implementations of quantum bits (qubits) continue to undergo too many errors to be scaled into useful quantum machines. An emerging strategy is to encode quantum information in the two ...meta-stable pointer states of an oscillator exchanging pairs of photons with its environment, a mechanism shown to provide stability without inducing decoherence. Adding photons in these states increases their separation, and macroscopic bit-flip times are expected even for a handful of photons, a range suitable to implement a qubit. However, previous experimental realizations have saturated in the millisecond range. In this work, we aim for the maximum bit-flip time we could achieve in a two-photon dissipative oscillator. To this end, we design a Josephson circuit in a regime that circumvents all suspected dynamical instabilities, and employ a minimally invasive fluorescence detection tool, at the cost of a two-photon exchange rate dominated by single-photon loss. We attain bit-flip times of the order of 100 seconds for states pinned by two-photon dissipation and containing about 40 photons. This experiment lays a solid foundation from which the two-photon exchange rate can be gradually increased, thus gaining access to the preparation and measurement of quantum superposition states, and pursuing the route towards a logical qubit with built-in bit-flip protection.
Case Report: We report the case of a 77-year-old man who was admitted to the intensive care unit with a serum digoxin level of 45.9 ng mL. The patient was hemodynamically stable throughout his ...hospital course and did not require antidigoxin antibody fragments. The elevated digoxin level was determined by subsequent testing to be falsely elevated by interference from human antimouse antibodies in his serum. A repeat digoxin measurement using an assay not affected by human antimouse antibodies indicated a level of 1.3 ng mL. Newer digoxin assays are not affected by human antimouse antibody interference, but clinicians should be aware of possible human antimouse antibody interference with older digoxin assays and in other tests utilizing mouse monoclonal antibody reagents.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Effect of methidathion (organophosphate) on the P-450 1A induction was assessed both by measurements of the induction of the EROD activity and of the immunodetection of the CYP1A protein in gudgeon. ...Fish were pre-treated with 5 mg kg
−1 of
β-naphthoflavone (BNF) and exposed to environmental concentrations of methidathion in laboratory. Methidathion proved to inhibit EROD induction in vivo and in vitro. In contrast, levels of immunoquantified CYP1A were found to be slightly higher in microsomes from fish exposed to 10–30 μg l
−1 of methidathion than in control fish exposed to BNF alone. This suggests that the inhibition of the EROD activity by methidathion resulted from a catalytic inhibition without decrease of the CYP1A protein.
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