Mesure des enthalpies de solution du CO2 dans les solutions aqueuses d'alcanolamines primaires aux très faibles taux de charge

National audienceLa détermination des enthalpies de solution des gaz, en particulier CO 2 et H 2 S, dans les solutions aqueuses d'alcanolamines a permis d'obtenir de nombreuses données pour alimenter les modèles thermodynamiques et améliorer les procédés de captage de ces gaz dans les fumées industrielles. Cependant le dispositif utilisé jusqu'alors ne permettait pas d'obtenir des résultats fiables pour les faibles taux de charge en gaz ( inférieur à 0.2). Les chaleurs de solution de CO 2 dans les solutions aqueuses d'amine ont été obtenues en utilisant un calorimeter BT2.15 de type calvet de la société SETARAM. Les cellules utilisées pour réaliser le mélange sont des cellules à écoulement développées au laboratoire. Lors de la mesure, les deux fluides, respectivement le gaz et la solution aqueuse, sont injectés dans la cellule de mélange à l'aide de deux pompes seringues haute pression (ISCO), à température et à pression constantes. L'enthalpie de solution est obtenue à partir de la différence entre le flux thermique mesuré par les thermopiles lors du mélange et celui obtenu lorsque la solution aqueuse circule dans le calorimètre sans CO 2. En faisant varier le débit des pompes, il est possible de déterminer l'enthalpie pour différents taux de charge en CO 2 (, en mol CO 2 / mol Amine). Cependant, les débits respectifs de gaz et de liquide qui doivent être utilisés pour mesurer l'enthalpie de solution pour des taux de charge inférieurs à 0.2 sont extrêmement différents et le débit de liquide trop important pour pouvoir réaliser la mesure. Afin de réduire cette différence entre les débits, nous remplacé le CO 2 pur par des mélanges de gaz (CO 2-N 2) de composition connue. L'azote n'étant pas soluble dans la solution aqueuse d'amine, l'effet thermique obtenu lors du mélange est alors directement lié à l'enthalpie de dissolution du CO 2. L'azote est alors considéré comme un gaz de dilution du CO 2. Un exemple est présenté ici pour les systèmes aqueux contenant de la monoéthanolamine (MEA) ou de l'aminométhylpropanol (AMP), ou un mélange des deux amines. Les résultats obtenus sont en très bon accord avec ceux obtenus pour les mesures avec du CO2 pur

Effect of Quinoa Seeds (Chenopodium quinoa) in Diet on some Biochemical Parameters and Essential Elements in Blood of High Fructose-Fed Rats

The effect of Chenopodium quinoa seeds on lipid profile, glucose level, protein metabolism and selected essential elements (Na, K, Ca, Mg) level was determined in high—fructose fed male Wistar rats. Fructose decreased significantly LDL [42%, p < 0.01] and activity of alkaline phosphatase [20%, p < 0.05], and increased triglycerides level [86%, p < 0.01]. The analysis of blood of rats fed quinoa indicated, that these seeds effectively reduced serum total cholesterol [26%, p < 0.05], LDL [57%, p < 0.008] and triglycerides [11%, p < 0.05] when compared to the control group. Quinoa seeds also significantly reduced the level of glucose [10%, p < 0.01] and plasma total protein level [16%, p < 0.001]. Fructose significantly decreased HDL [15%, p < 0.05] level in control group but when the quinoa seeds were added into the diet the decrease of HDL level was inhibited. Quinoa seeds did not prevent any adverse effect of increasing triglyceride level caused by fructose. It was shown in this study that quinoa seeds can reduce most of the adverse effects exerted by fructose on lipid profile and glucose level

Gut microbiota-derived propionate reduces cancer cell proliferation in the liver

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Nuclear translocation of haeme oxygenase-1 is associated to prostate cancer

The role of oxidative stress in prostate cancer has been increasingly recognised. Acute and chronic inflammations generate reactive oxygen species that result in damage to cellular structures. Haeme oxygenase-1 (HO-1) has cytoprotective effects against oxidative damage. We hypothesise that modulation of HO-1 expression may be involved in the process of prostate carcinogenesis and prostate cancer progression. We thus studied HO-1 expression and localisation in 85 samples of organ-confined primary prostate cancer obtained via radical prostatectomy (Gleason grades 4–9) and in 39 specimens of benign prostatic hyperplasia (BPH). We assessed HO-1 expression by immunohistochemical staining. No significant difference was observed in the cytoplasmic positive reactivity among tumours (84%), non-neoplastic surrounding parenchyma (89%), or BPH samples (87%) (P=0.53). Haeme oxygenase-1 immunostaining was detected in the nuclei of prostate cancer cells in 55 of 85 (65%) patients but less often in non-neoplastic surrounding parenchyma (30 of 85, 35%) or in BPH (9 of 39, 23%) (P<0.0001). Immunocytochemical and western blot analysis showed HO-1 only in the cytoplasmic compartment of PC3 and LNCaP prostate cancer cell lines. Treatment with hemin, a well-known specific inducer of HO-1, led to clear nuclear localisation of HO-1 in both cell lines and highly induced HO-1 expression in both cellular compartments. These findings have demonstrated, for the first time, that HO-1 expression and nuclear localisation can define a new subgroup of prostate cancer primary tumours and that the modulation of HO-1 expression and its nuclear translocation could represent new avenues for therapy

Honey, a Gift from Nature to Health and Beauty: A Review

Benefits of honey are contributed by the composition of its elements such as glucose, fructose, glucose oxidase, vitamins and phenolic compounds. For health, honey can be used to treat wounds due to the antibacterial activity conferred by the hydrogen peroxide produced by glucose oxidase in honey. Anti-inflammatory, anti-oxidant, deodorizing and tissue regeneration activities in honey also help in the wound healing process. It can also be an alternative sweetener for diabetic patients to ensure compliance to a healthy diet. Moreover, honey exerts several effects such as lowering low density lipids and increasing high density lipids, thus reducing risk of atherosclerosis. In terms of beauty, honey can be used on skin and hair. It moisturizes skin through its natural humectant properties contributed by high contents of fructose and glucose. Honey treats acne on the skin due to its antibacterial activity, anti-inflammatory action and tissue repair. The hair can benefit from honey in such a way that the hair has abundance, and becomes easier to comb. However, there have not been as many studies regarding the use of honey in skin in comparison to its use for health. Therefore, future studies on honey could research its use, action and benefits in both cosmetics and dermatology

Cobalt protoporphyrin represses osteoclastogenesis through blocking multiple signaling pathways

Cobalt protoporphyrin (CoPP) is a metallo-protoporphyrin that works as a powerful inducer of heme oxigenase-1 (HO-1) in various tissues and cells. Our recent studies have demonstrated that induction of HO-1 by several reagents inhibited differentiation and activation of osteoclasts (OCLs), which are multinucleated bone resorbing cells. However, the effects of CoPP on osteoclastogenesis remain to be elucidated. In this study, we report that CoPP inhibits receptor activator of nuclear factor κB ligand (RANKL)-induced OCL formation in a dose dependent manner. Importantly, CoPP had little cytotoxicity, but rather enhanced cell proliferation of OCLs. CoPP suppressed the protein levels of nuclear factor of activated T cells cytoplasmic-1 (NFATc1) as well as those of OCLs markers such as Src and cathepsin K, which are transcriptionally regulated by NFATc1 in mature OCLs. Western blot analyses also showed that CoPP abolished RANKL-stimulated phosphorylation of several major signaling pathways such as IκB, Akt, ERK, JNK and p38 MAPKs in OCL precursor cells. Thus, our results show that CoPP represses osteoclastogenesis through blocking multiple signaling pathways

Ecology and biogeography of megafauna and macrofauna at the first known deep-sea hydrothermal vents on the ultraslow-spreading Southwest Indian Ridge

0000-0002-9489-074X© The Author(s) 2016. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ The attached file is the published version of the article

Calorimetric methods for key properties in refrigeration cycles.

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