Live Imaging at the Onset of Cortical Neurogenesis Reveals Differential Appearance of the Neuronal Phenotype in Apical versus Basal Progenitor Progeny

The neurons of the mammalian brain are generated by progenitors dividing either at the apical surface of the ventricular zone (neuroepithelial and radial glial cells, collectively referred to as apical progenitors) or at its basal side (basal progenitors, also called intermediate progenitors). For apical progenitors, the orientation of the cleavage plane relative to their apical-basal axis is thought to be of critical importance for the fate of the daughter cells. For basal progenitors, the relationship between cell polarity, cleavage plane orientation and the fate of daughter cells is unknown. Here, we have investigated these issues at the very onset of cortical neurogenesis. To directly observe the generation of neurons from apical and basal progenitors, we established a novel transgenic mouse line in which membrane GFP is expressed from the beta-III-tubulin promoter, an early pan-neuronal marker, and crossed this line with a previously described knock-in line in which nuclear GFP is expressed from the Tis21 promoter, a pan-neurogenic progenitor marker. Mitotic Tis21-positive basal progenitors nearly always divided symmetrically, generating two neurons, but, in contrast to symmetrically dividing apical progenitors, lacked apical-basal polarity and showed a nearly randomized cleavage plane orientation. Moreover, the appearance of beta-III-tubulin–driven GFP fluorescence in basal progenitor-derived neurons, in contrast to that in apical progenitor-derived neurons, was so rapid that it suggested the initiation of the neuronal phenotype already in the progenitor. Our observations imply that (i) the loss of apical-basal polarity restricts neuronal progenitors to the symmetric mode of cell division, and that (ii) basal progenitors initiate the expression of neuronal phenotype already before mitosis, in contrast to apical progenitors

Effects of Ce addition and Pt precursor on the activity of Pt/Al2O3 catalysts for wet oxidation of phenol

The effects of Ce addition on the activity of Pt/Al2O3 catalysts were investigated for the wet oxidation of phenol. Platinum was impregnated on gamma-Al2O3 by using two different precursors: one is anionic (i.e., H2PtCl6) and the other is cationic (i.e., Pt(NH3)(4)Cl-2). The Pt catalysts from the former showed much higher activity than that from the latter, because the former resulted in a better metal dispersion than the latter. Cerium addition lowered the catalytic activity of Pt/Al2O3 catalysts from H2PtCl6, while it improved the activity of Pt/Al2O3 catalysts from Pt(NH3)(4)Cl-2. The effect of Ce addition on the wet oxidation activity of Pt-Ce/Al2O3 could be explained by the differences in Pt dispersion and the Pt-Ce interactions

Nature of carbonaceous deposits on the alumina supported transition metal oxide catalysts in the wet air oxidation of phenol

Al2O3 supported transition metal (Mn, Fe, Co, Ni, and Cu) oxide catalysts were prepared and tested for the wet oxidation of phenol. The supported copper oxide catalysts showed the highest catalytic activity due to their highest surface reducibility. There was carbonaceous deposits on the used catalysts for the wet oxidation of phenol and the supported manganese oxide catalysts showed the highest amount of carbonaceous deposits. These carbonaceous deposits must have their own micropores which resulted in the decrease of the pore volume and the increase of the surface area. The NMR and FTIR spectroscopy showed that the carbonaceous deposits were mostly of aromatic nature and contained some oxygen-bearing groups such as carboxylic acids and alcohols

Effect of lanthanum addition on the thiophene hydrodesulfurization activity over Al-MCM-41 supported molybdenum catalysts

A series of Al-MCM-41 modified with 1-7% lanthanum were used as supports to prepare the Mo/La-Al-MCM-41 catalysts containing 10 wt.% molybdenum. The supports and catalysts were characterized with XRD, BET, XPS, TPD, TEM and SEM, and their catalytic activities were tested for thiophene hydrodesulfurization. The La addition did not cause any significant collapse of the structure and morphology of Al-MCM-41 samples, and increased the acidity of Al-MCM-41 samples. The Mo/La-Al-MCM-41 catalysts showed higher thiophene HDS activity than nonmodified catalysts. The La-modified catalysts showed an enhanced butene selectivity but a decreased tetrahydrothiophene selectivity, indicating that the La-Al-MCM-41 supports contained a larger amount of acid sites. (c) 2005 Elsevier B.V. All rights reserved

Characteristics of CoMo catalysts supported on modified MCM-41 and MCM-48 materials for thiophene hydrodesulfurization

The potential of two different mesoporous materials, MCM-41- and MCM-48-supported sulfided CoMo bimetallic catalysts, for hydrodesulfurization (HDS) of thiophene at specific conditions was explored to investigate the effect of channel connectivity on HDS activity. The hydrothermal stability of MCM-41 and MCM-48 was improved remarkably by a post-salt treatment technique. Aluminum incorporation to mesoporous material frameworks improved acidity and hydrothermal stability. Mesoporous-material-supported CoMo catalysts with different Co/Mo atomic ratios were prepared by coimpregnation of Co(NO3)(2)center dot 6H(2)O and (NH4)(6)Mo(7)O(24)center dot 4H(2)O. The characterization of the catalysts was carried out by X-ray diffraction (XRD), N-2 adsorption/desorption, NH3-temperature-programmed desorption (NH3-TPD), transmission electron microscopy (TEM), CO chemisorption, elemental analysis (EA), and C-13 NMR. MCM-41-supported catalysts showed a small decrease in activity compared to MCM-48-supported catalysts. The optimal Co/Mo atomic ratio for MCM-41- and MCM-48-supported series of catalysts was 3:7. The aluminosilicate-supported CoMo catalysts showed higher activities than their siliceous counterparts

Selective hydrogenation of cinnamaldehyde to cinnamyl alcohol on L-zeolite supported catalysts

The selective hydrogenation of cinnamaldehyde was studied on Al2O3 and L zeolites supported catalysts. The addition of Sn improves the selectivity to cinnamyl alcohol on Pt/Al2O3 catalysts while the reaction activity has a maximum at Sn/Pt atomic ratio of 0.5. It is interesting to find that Pt/L catalysts show both high activities and selectivities to carbonyl hydrogenated product cinnamyl alcohol. On Pt/RbL and Pt/SrL catalysts, the selectivities to cinnamyl alcohol are higher than 90% even with the cinnamaldehyde conversion of 95%. The effects of metal morphology, channel structures and basicities of L-zeolites are discussed

FPGA-based trigger system for the LUX dark matter experiment

LUX is a two-phase (liquid/gas) xenon time projection chamber designed to detect nuclear recoils resulting from interactions with dark matter particles. Signals from the detector are processed with an FPGA-based digital trigger system that analyzes the incoming data in real-time, with just a few microsecond latency. The system enables first pass selection of events of interest based on their pulse shape characteristics and 3D localization of the interactions. It has been shown to be >99% efficient in triggering on S2 signals induced by only few extracted liquid electrons. It is continuously and reliably operating since its full underground deployment in early 2013. This document is an overview of the systems capabilities, its inner workings, and its performance

신증후군환자에 대한 사이크로스포린의 유효성 및 안전성 평가를 위한 16주 공개 다기관 제 3상 임상시험

A multicenter prospective study was done in four-university hospital to evaluate the efficacy and safety of cyclosporin A(CyA, Cipol-N) in 64 patients with adult nephrotic syndrome mean age 34.8 years, male:female 2.4:1, duration of disease 38.0±40.9months, 31 patients with MCD, 33 patients with Non-MCD(8 FSGS, 14 MGN, 7 MPGN, 2 lupus nephritis, 1 HBsAg associated GN)]. The prior steroid responses of these patients were 17 steroid dependent, 9 frequent relapser, 4 steroid resistant and 1 other in MCD patients, and 5 steroid dependent, 5 frequent relapser, 22 steroid resistant and 1 other in Non-MCD patients. After a 2-week steroid(predni-solon 10mg/day or deflazacort 12mg/day) run-in period, CyA 5mg/kg/day and prednisolone 10mg/day (or deflazacort 12mg/day) were administered for up to 16 weeks. Of the 64 patients enrolled, ll patients were dropped out prematurely due to adverse events or protocol violation. Of the 53 patients who completed the study, 27 had MCD and 26 had Non- MCD. High response(CR and PR) rate of 68%(36/53) were obtained with CyA treatment in all patients. Although the response rate in MCD was significantly higher than that in Non-MCD(89 vs. 46%, p<0.05) and response rates were significantly different according to the previous steroid responses by univariate analysis, only previous steroid responses affected the response to CyA significantly by Logistic multiple regression analysis(p=0.03, RR 7.08); responses were 84%(27/32) in steroid dependent and frequent relapser patients, and 37%(7/19) in steroid resistant patients. 24-hr proteinuria significantly decreased after 2 weeks and serum albumin and cholesteroi increased significantly after 4 weeks of treatment compared to baseline level. The serum creatinine level was not changed during the study. No serious and unexpected side event was observed. In conclusion, cyclosporine therapy is a safe and effective mode of treatment in patients with ne-phrotic syndrome, especially in those who need pro- longed administration of steroids with resulting in unavoidable steroid complications such as frequent relapser and steroid dependent type. The patients with steroid resistant type and contraidications of steroid administration such as DM, aseptic bone neerosis etc. can also be candidates for this treatment