Rapid Cycling and Exceptional Yield in a Metal-Organic Framework Water Harvester.

Sorbent-assisted water harvesting from air represents an attractive way to address water scarcity in arid climates. Hitherto, sorbents developed for this technology have exclusively been designed to perform one water harvesting cycle (WHC) per day, but the productivities attained with this approach cannot reasonably meet the rising demand for drinking water. This work shows that a microporous aluminum-based metal-organic framework, MOF-303, can perform an adsorption-desorption cycle within minutes under a mild temperature swing, which opens the way for high-productivity water harvesting through rapid, continuous WHCs. Additionally, the favorable dynamic water sorption properties of MOF-303 allow it to outperform other commercial sorbents displaying excellent steady-state characteristics under similar experimental conditions. Finally, these findings are implemented in a new water harvester capable of generating 1.3 L kgMOF -1 day-1 in an indoor arid environment (32% relative humidity, 27 °C) and 0.7 L kgMOF -1 day-1 in the Mojave Desert (in conditions as extreme as 10% RH, 27 °C), representing an improvement by 1 order of magnitude over previously reported devices. This study demonstrates that creating sorbents capable of rapid water sorption dynamics, rather than merely focusing on high water capacities, is crucial to reach water production on a scale matching human consumption

Le botulisme expérimental du Cheval provoqué par la toxine D. Evolution et essai de sérothérapie

Jacquet Jean, Prévot A. R. Le botulisme expérimental du Cheval provoqué par la toxine D. Evolution et essai de sérothérapie. In: Bulletin de l'Académie Vétérinaire de France tome 105 n°6, 1952. pp. 247-253

Nouvelles recherches sur le botulisme du vison et du furet et la vaccination antibotulique de ces mustélidés

Prévot A. R., Silloc R. Nouvelles recherches sur le botulisme du vison et du furet et la vaccination anti-bolutique de ces mustélidés. In: Bulletin de l'Académie Vétérinaire de France tome 110 n°2, 1957. pp. 93-102

Le botulisme expérimental du cheval provoqué par la toxine D Symptômes, pathogénie, diagnostic, lésions

Jacquet Jean, Prévot A. R. Le botulisme expérimental du Cheval provoqué par la toxine D. Symptômes, pathogénie, diagnostic, lésions. In: Bulletin de l'Académie Vétérinaire de France tome 106 n°2, 1953. pp. 135-140

Hybrides de Cobayes sauvages et de cobayes domestiques.

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Enzootie à « W. perfringens A » dans un élevage de visons

Prévot A., Villemin Martial, Kréguer A., Vallée A. Enzootie à “W. perfringens A” dans un élevage de visons. In: Bulletin de l'Académie Vétérinaire de France tome 114 n°3, 1961. pp. 115-117

The mechanism of self-reversal of thermoremanence in natural hemoilmenite crystals: new experimental data and model

17 pages, including 7 figuresNew magnetic and mineralogical findings on self-reversing hemoilmenite (Fe2-y Tiy O3) grains from Pinatubo lavas (1991 eruption) provide important clues regarding the acquisition process of reverse thermoremanent magnetization (rTRM) in this solid solution series. Magnetic Force Microscopy indicates the presence of multidomain magnetic structures in coexisting strongly and weakly magnetic crystallographic regions having compositions of y0.54 and y0.53, respectively. Yet, continuous thermal demagnetization of natural and laboratory TRM carried out on both whole rock samples and single hemoilmenite crystals shows that the magnitude of a normal TRM (nTRM) component, observed at temperatures above the Curie point of the strongly magnetic self-reversing regions, is much too large to be carried by a phase that is entirely cation-disordered. Consistent with this observation are findings using Transmission Electron Microscopy (TEM) which, in contrast to that what is commonly assumed, reveals the weakly magnetic regions to be magnetically heterogeneous. Specifically, these regions are found to contain tiny (20-40nm) domains that are cation-ordered and evidently ferrimagnetic dispersed within the cation-disordered, presumably spin-canted antiferromagnetic matrix. Given these findings, we argue that the so-called nTRM-carrying x-phase is itself partially cation-ordered, and thus ferrimagnetic, as postulated first by Ishikawa and Syono (1962). We propose a “nanophase” self-reversal model for the ilmenite-hematite solid solution series in which the rTRM and nTRM components are carried by the cores and margins, respectively, of the tiny, partially cation-ordered nano-sized domains observed by TEM. Due to the partial cation order, both the core and the margin of each domain are expected to behave in a ferrimagnetic fashion at temperatures below their respective Curie points. However, given the kinetics of the ordering process, their cation distributions need be antiphase, which causes their magnetic moments to be oppositely aligned. Since it is most reasonable to consider each margin to be slightly more Fe-rich than the inside core, upon cooling the margins acquire a magnetic remanence first (a nTRM). Then, upon further cooling, given that the intralayer and interlayer nearest-neighbor superexchange interactions are ferromagnetic and antiferromagnetic, respectively, the net magnetic moment of the core material need be oppositely aligned (producing a rTRM). The nano-sized regions would indeed behave in a superparamagnetic (SP) fashion if magnetically uncoupled to adjacent material; however, the spins in the margins (the x-phase) must be locked through superexchange to those of the surrounding disordered matrix, which we also claim to be locally enriched in iron. If so, then the magnetization of the x-phase can be both highly-coercive and thermally stable, as observed experimentally. Upon stepwise thermal demagnetization, the self-reversed remanence measured at room temperature is not destroyed until the unblocking temperature of the disordered Fe-enriched aureole (approximately 410°C) is reached. Mineralogical considerations and magnetic evidence from previous works suggest that this model is generally valid for self-reversed dacitic pumice, in particular the Mt. Haruna dacite and the 1985 Nevado del Ruiz dacitic andesite

Disparate effects of chronic and acute theophylline on cyclosporine A nephrotoxicity

Abstract : We previously developed a model of acute cyclosporine A (CsA)-induced vasomotor nephrotoxicity in rabbits. As exogenous adenosine infusion mimics the haemodynamic changes that characterize acute renal failure (ARF), we wanted to know whether adenosine was a mediator in this model and whether an adenosine receptor blocker could prevent the CsA-induced ARF. Group 1 were untreated controls. Group 2 received CsA (25 mg/kg per day) for 5 days. Renal function parameters were measured, showing ARF in all animals compared to controls. Theophylline (1 mg/kg i.v. bolus) was then administered and renal function was reassessed. Theophylline significantly reduced renal vascular resistance (-8%) and increased renal blood flow (RBF) (+20%), glomerular filtration rate (GFR) (+50%), filtration fraction (+24%) and diuresis (+73%), suggesting that adenosine was involved in the CsA-induced ARF. In group 3, theophylline (30 mg/kg per day) was given concomitantly with CsA for 5 days. GFR was normalized, but theophylline did not hinder the drop in RBF seen with CsA alone in group 2. Microscopy observation of the kidneys showed that chronic theophylline administration aggravated the morphological changes induced by CsA alone. We conclude that CsA administration for 5 days induced a vasomotor nephropathy with an adenosine-mediated afferent arteriolar constriction which cannot be prevented by concomitant theophylline administratio