Synthesis of Some New Thienylazetidinones and Thiazolidinones Containing Pyrazolines

Condensation of thiophene-2-carboxa.ldehyde with 4-aminoacetophenone gave a quantitative yield of 4-(thienylideneamino)acetophenone( I). Condensation of I with aromatic aldehydes yielded the corresponding 4-( 4-substituted-phenyl)-4\u27 -(2-thienyleneamino )chalcone( II). Interaction of II with hydrazines gave 3-(4-2\u27-thienylideneamino) phenylpyrazolines (III, IV). Cyclocondensation of chloroacetyl chloride (or mercaptoa cetic acid) on III or IV gave 3-chloro-1-( 4-pheny lpyrazolin-3\u27 -yl)-4-(2" - thieny l)azetidin -2- ones (V, VI) and 3-(4-phenylpyrazolin-3\u27-yl)-2-(2"-thienyl)thiazolidin-4- -ones (VII, VIII), respectivel

Regulation of Osteogenic Differentiation of Placental-Derived Mesenchymal Stem Cells by Insulin-Like Growth Factors and Low Oxygen Tension

Placental mesenchymal stem cells (PMSCs) are multipotent cells that can differentiate in vitro to multiple lineages, including bone. Insulin-like growth factors (IGFs, IGF-1 and IGF-2) participate in maintaining growth, survival, and differentiation of many stem cells, including osteoprogenitors. Low oxygen tension (PO2) can maintain stem cell multipotency and impede osteogenic differentiation. In this study, we investigated whether PMSC osteogenic differentiation is influenced by low PO2 and by IGFs. Our results indicated that low PO2 decreased osteogenic markers RUNX2 and OPN; however, re-exposure to higher oxygen tension (room air) restored differentiation. IGFs, especially IGF-1, triggered an earlier expression of RUNX2 and enhanced OPN and mineralization. RUNX2 was phosphorylated in room air and augmented by IGFs. IGF-1 receptor (IGF-1R) was increased in low PO2 and reduced by IGFs, while insulin receptor (IR) was increased in differentiating PMSCs and enhanced by IGF-1. Low PO2 and IGFs maintained higher IR-A which was switched to IR-B in room air. PI3K/AKT was required for osteogenic differentiation, while MEK/ERK was required to repress an RUNX2 and OPN increase in low PO2. Therefore, IGFs, specifically IGF-1, trigger the earlier onset of osteogenic differentiation in room air, whereas, reversibly, low PO2 impedes complete differentiation by maintaining higher multipotency and lower differentiation markers

Multiresolution analysis of point processes and statistical thresholding for wavelet-based intensity estimation

We take a wavelet based approach to the analysis of point processes and the estimation of the first order intensity under a continuous time setting. A multiresolution analysis of a point process is formulated which motivates the definition of homogeneity at different scales of resolution, termed $J$-th level homogeneity. Further to this, the activity in a point processes' first order behavior at different scales of resolution is also defined and termed $L$-th level innovation. Likelihood ratio tests for both these properties are proposed with asymptotic distributions provided, even when only a single realization of the point process is observed. The test for $L$-th level innovation forms the basis for a collection of statistical strategies for thresholding coefficients in a wavelet based estimator of the intensity function. These thresholding strategies are shown to outperform the existing local hard thresholding strategy on a range of simulation scenarios.Comment: 48 pages, 8 figure

Observation of the spin Peltier effect

We report the observation of the spin Peltier effect (SPE) in the ferrimagnetic insulator Yttrium Iron Garnet (YIG), i.e. a heat current generated by a spin current flowing through a Platinum (Pt)|YIG interface. The effect can be explained by the spin torque that transforms the spin current in the Pt into a magnon current in the YIG. Via magnon-phonon interactions the magnetic fluctuations modulate the phonon temperature that is detected by a thermopile close to the interface. By finite-element modelling we verify the reciprocity between the spin Peltier and spin Seebeck effect. The observed strong coupling between thermal magnons and phonons in YIG is attractive for nanoscale cooling techniques.Comment: 5 pages, 3 figures, 4 pages supplementary information, 4 supplementary figure

The Roles of Insulin-Like Growth Factors in Mesenchymal Stem Cell Niche

Many tissues contain adult mesenchymal stem cells (MSCs), which may be used in tissue regeneration therapies. However, the MSC availability in most tissues is limited which demands expansion in vitro following isolation. Like many developing cells, the state of MSCs is affected by the surrounding microenvironment, and mimicking this natural microenvironment that supports multipotent or differentiated state in vivo is essential to understand for the successful use of MSC in regenerative therapies. Many researchers are, therefore, optimizing cell culture conditions in vitro by altering growth factors, extracellular matrices, chemicals, oxygen tension, and surrounding pH to enhance stem cells self-renewal or differentiation. Insulin-like growth factors (IGFs) system has been demonstrated to play an important role in stem cell biology to either promote proliferation and self-renewal or enhance differentiation onset and outcome, depending on the cell culture conditions. In this review, we will describe the importance of IGFs, IGF-1 and IGF-2, in development and in the MSC niche and how they affect the pluripotency or differentiation towards multiple lineages of the three germ layers

Anesthesie topique par oxybuprocaine dans la chirurgie de cataracte: à propos de 100 cas

L'anesthésie topique lors de la chirurgie de la cataracte par phacoemulsification est devenue le meilleur choix pour les ophtalmologistes, Nous rapportons les résultats d'une étude prospective incluant 100 cas de cataractes simples opérées sous anesthésie topique par Oxybuprocaïne 0.4%, l'objectif est d'évaluer les avantages et les inconvénients, l'efficacité et la tolérance de ce protocole dans la chirurgie de cataracte par phacoemulsification. Étude prospective portant sur 100 patients opérés pour cataracte simple stade I, II et III sous anesthésie topique par instillation de quatre gouttes d'Oxybuprocaïne 0.4% collyre, nous avons analysé les complications rencontrées et le confort des patients à l'aide de l'échelle visuelle analogique. La tolérance du patient durant l'acte chirurgical est excellente ainsisur échelle visuelle analogique(EVA) de la douleur était de au alentour de 1 dans la majorité des cas (87 cas/ 92) soit (94% des cas). Ce protocole d'anesthésie topique permet l'éviction de toutes les complications liées aux anesthésies péribulbaire, latérobulbaire ou sous ténonienne et les risques de toxicité endothéliale par injection d'anesthésique intracamérulaire et semble apporter une efficacité anesthésique suffisante, une excellente tolérance. Dans 92% des cas, une anesthésie topique de surface par Oxybuprocaïne 0.4% collyre apparaît suffisante pour une chirurgie de cataracte simple

Simplified Numeric Simulation Approach for CO2,g_{2,g}-Water Flow and Trapping at Near-Surface Conditions

To simulate CO$_{2,g}$-water flow in tank experiments, subject to viscous, gravitational and capillary forces as well as the dissolution of this gas (CO$_{2,aq}$), we constructed a simple pseudo black-oil model. Simple PVT correlations were used for gas density, viscosity, and solubility as based on experimental studies and equations of state from the literature. These solubility calculations assume instantaneous chemical equilibrium. The applicability of the approach is investigated by modeling the FluidFlower tank experiment (Nordbotten et al., 2022). The simulation captures the expected physical phenomena, including capillary filtration, gravitational segregation, and dissolution fingering. An error in the total mass, due to ignoring solubility variations with pressure remains acceptable as long as the pressure variation in the tank is small.Comment: Submitted to Transport in Porous Medi

Turbulent film condensation in a vertical tube in presence of non condensable gas

This paper presents the simulation of the condensation of methanol vapour in the presence of non-condensable gas in turbulent flows in a vertical tube. The liquid and gas stream are approached by two coupled turbulent boundary layer. For solving the coupled governing equations for liquid film and gas flow together with the interfacial matching conditions an implicit finite difference method is employed. The effect of the influencing parameters are studied so the effect of inlet Reynolds number, the effect of temperature gradient, mass fraction are illustrated. The numerical results demonstrate that an important concentration of no-condensable gas reduces the heat transfer coefficient and film thickness considerably. The local heat flux and film thickness increase as tube surface temperature decreases at any bulk concentration of non-condensable gas. Moreover, inlet velocity increases as film thickness decreases and heat flux increases