SIRT3 controls brown fat thermogenesis by deacetylation regulation of pathways upstream of UCP1.

Objective Brown adipose tissue (BAT) is important for thermoregulation in many mammals. Uncoupling protein 1 (UCP1) is the critical regulator of thermogenesis in BAT. Here we aimed to investigate the deacetylation control of BAT and to investigate a possible functional connection between UCP1 and sirtuin 3 (SIRT3), the master mitochondrial lysine deacetylase.Methods We carried out physiological, molecular, and proteomic analyses of BAT from wild-type and Sirt3KO mice when BAT is activated. Mice were either cold exposed for 2 days or were injected with the β3-adrenergic agonist, CL316,243 (1 mg/kg; i.p.). Mutagenesis studies were conducted in a cellular model to assess the impact of acetylation lysine sites on UCP1 function. Cardiac punctures were collected for proteomic analysis of blood acylcarnitines. Isolated mitochondria were used for functional analysis of OXPHOS proteins.Results Our findings showed that SIRT3 absence in mice resulted in impaired BAT lipid use, whole body thermoregulation, and respiration in BAT mitochondria, without affecting UCP1 expression. Acetylome profiling of BAT mitochondria revealed that SIRT3 regulates acetylation status of many BAT mitochondrial proteins including UCP1 and crucial upstream proteins. Mutagenesis work in cells suggested that UCP1 activity was independent of direct SIRT3-regulated lysine acetylation. However, SIRT3 impacted BAT mitochondrial proteins activities of acylcarnitine metabolism and specific electron transport chain complexes, CI and CII.Conclusions Our data highlight that SIRT3 likely controls BAT thermogenesis indirectly by targeting pathways upstream of UCP1

Вплив збільшення концентрацій при отриманні тонкої плівки Cu2ZnSnS4

Спрей-піроліз – це проста техніка, що використовується для виробництва великих тонких плівок. У роботі ми повідомляємо про виготовлення тонких плівок Cu2ZnSnS4 (CZTS) методом спрей-піролізу на скляних підкладках з використанням різних водних розчинів. Отже, ми вирішили змінювати концентрації аніонів (S) та катіонів (Cu, Zn, Sn). Метою цього вибору є аналіз EDX, щоб відсоток міді був ближче до 25 %; з іншого боку, цинк і олово складають близько 12.5 %, а сірка – 50 %. Структурний та хімічний склад, морфологічні та оптичні властивості тонких плівок CZTS досліджували за допомогою рентгенівської дифракції (XRD) та Раманівської спектроскопії, енергетично-дисперсійного рентгенівського аналізу (EDAX), скануючої електронної мікроскопії (SEM) та атомно-силової мікроскопії (AFM) та спектроскопічного аналізу в ультрафіолетовому та видимому діапазонах відповідно. Рентгенівська дифракція показала утворення кестеритової структури з домінуючими піками в напрямках (112), (220) та (312). Раманівська спектроскопія підтвердила наявність внутрішньої напруги стиску в тонких плівках CZTS. Аналіз EDX показав кращу стехіометрію при оптимізації концентрацій прекурсора. Тонкі плівки CZTS демонстрували низьку оптичну пропускну здатність та оптичне поглинання вище 5×104 см – 1, завдяки чому тонкі плівки CZTS, підготовлені методом спрей-піролізу, підходять для сонячних батарей CZTS.Spray pyrolysis is a simple and low cost technique used for large thin films fabrication. In this paper, we reported the preparation of Cu2ZnSnS4 (CZTS) thin films with spray pyrolysis on glass substrates using different aqueous solutions. So, we chose to vary anions (S) and cations (Cu, Zn, Sn) concentrations. The purpose of this choice is the EDX analysis so that the percentage of copper is closer to 25 %; on the other hand, zinc and tin are around 12.5 % and sulfur at 50 %. The structural, chemical composition, morphological and optical properties of CZTS thin films were investigated using X-ray diffraction (XRD) and Raman spectroscopy, energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM) and atomic force microscopy (AFM), and UV-visible spectroscopy analysis, respectively. The X-ray diffraction showed the formation of kesterite structure with dominant peaks along (112), (220) and (312) directions. Raman spectroscopy confirmed the existence of internal compressive stress in the CZTS thin films. The EDX analysis showed a better stoichiometry when optimizing the precursor concentrations. CZTS thin films showed low optical transmission and optical absorbance higher than 5×104 сm–1, which make the CZTS thin films prepared by spray pyrolysis technique suitable for CZTS solar cells

QSAR studies of 1,2,5-thiadiazole derivatives analogues of aceclidine as potent M1 muscarinic agonists

International audienceIn the present study, Quantitative structure-activity relationship (QSAR) study have been performed on twenty molecules of 1,2,5-thiadiazole derivatives. The compounds studied are the analogues of aceclidine as potent M1 muscarinic agonists. A multiple linear regression (MLR) procedure was used to design the relationships between molecular descriptors and biological activity of the 1,2,5- thiadiazole derivatives. The predictivity of the model was estimated by cross-validation with the leave-one-outmethod. Our results suggest a QSAR model based on the following descriptors Log P , HE, Pol, MR, MV, and MW, SAG, and Etotal. High correlation between experimental and predicted activity values was observed, indicating the validation and the good quality of the established QSAR models. © 2018 American Scientific Publishers

Measuring static thermal permeability and inertial factor of rigid porous materials

International audienceAn acoustic method based on sound transmission is proposed for deducing the static thermal permeability and the inertial factor of porous materials having a rigid frame at low frequencies. The static thermal permeability of porous material is a geometrical parameter equal to the inverse trapping constant of the solid frame [Lafarge et al., J. Acoust. Soc. Am. 102, 1995 (1997)] and is an important characteristic of the porous material. The inertial factor [Norris., J. Wave Mat. Interact. 1, 22 365 (1986)] describes the fluid structure interactions in the low frequency range (1-3 kHz). The proposed method is based on a temporal model of the direct and inverse scattering problems for the propagation of transient audible frequency waves in a homogeneous isotropic slab of porous material having a rigid frame. The static thermal permeability and the inertial factor are determined from the solution of the inverse problem. The minimization between experiment and theory is made in the time domain. Tests are performed using industrial plastic foams. Experimental and theoretical data are in good agreement. Furthermore, the prospects are discussed. This method has the advantage of being simple, rapid, and efficient