Easy Access to a Library of Alkylindoles: Reductive Alkylation of Indoles with Carbonyl Compounds and Hydrosilanes under Indium Catalysis

By applying carbonyl compounds as sources of alkyl groups to the indium‐catalyzed reductive alkylation of indoles, a reliable and practical method capable of offering a wide range of alkylindoles with structural diversity has been developed. An important feature of this method is that the loading of the indium catalyst can be reduced by more than that of the original alkyne‐based system.

     

Interconnected pores on the walls of a polymeric honeycomb monolith structure created by the unidirectional freezing of a binary polymer solution

Interconnected submicron pores were created on the walls of a honeycomb monolith structure by the unidirectional freezing of a binary polymer solution. Agglomerated globules of polyethylene glycol (PEG) in a binary solution of polystyrene (PS) and PEG in 1,4-dioxane solvent were frozen unidirectionally in a liquid nitrogen bath. Removing the frozen solvent and the agglomerated globules of PEG by freeze-drying and leaching, respectively, enabled us to create interconnected pores in the PS walls. The combination of PS and PEG was effective in creating interconnected pores in the walls because PS and PEG are poorly soluble in one another. The higher freezing rate and lower PEG weight fraction of the binary solution effectively reduced the pore size in the microtube walls.     

Elastic large deflection analysis of plates subjected to uniaxial thrust using meshfree Mindlin-Reissner formulation

A meshfree approach for plate buckling/post-buckling problems in the case of uniaxial thrust is presented. A geometrical nonlinear formulation is employed using reproducing kernel approximation and stabilized conforming nodal integration. The bending components are represented by Mindlin–Reissner plate theory. The formulation has a locking-free property in imposing the Kirchhoff mode reproducing condition. In addition, in-plane deformation components are approximated by reproducing kernels. The deformation components are coupled to solve the general plate bending problem with geometrical non-linearity. In buckling/post-buckling analysis of plates, the in-plane displacement of the edges in their perpendicular directions is assumed to be uniform by considering the continuity of plating, and periodic boundary conditions are considered in assuming the periodicity of structures. In such boundary condition enforcements, some node displacements/rotations should be synchronized with others. However, the enforcements introduce difficulties in the meshfree approach because the reproducing kernel function does not have the so-called Kronecker delta property. In this paper, the multiple point constraint technique is introduced to treat such boundary conditions as well as the essential boundary conditions. Numerical studies are performed to examine the accuracy of the multiple point constraint enforcements. As numerical examples, buckling/post-buckling analyses of a rectangular plate and stiffened plate structure are presented to validate the proposed approach.     

Formation of carbamates and cross-linking of microbial poly(ε-<Emphasis Type="SmallCaps">l</Emphasis>-lysine) studied by <Superscript>13</Superscript>C and <Superscript>15</Superscript>N solid-state NMR

Formation of carbamates by amino groups of poly(ε-l-lysine) (ε-PL) and cross-linking of ε-PL were studied by using ¹³C and ¹⁵N solid-state NMR. It is a characteristic found in ε-PL cast from basic aqueous solution exposed to the air or gaseous CO₂. It is not observed in ε-PL cast from acidic aqueous solution and ε-PL cast from degassed aqueous solution under CO₂ free environment. The carboxyl carbon and amide nitrogen appear at 164 ppm in ¹³C spectrum and 92 ppm in ¹⁵N spectrum, respectively, which arise when some amino groups of ε-PL react with gaseous CO₂ to make carbamates. In addition to these peaks a peak at 171 ppm appears. We assigned it to amide C=O carbons which can not make intermolecular hydrogen bondings since there exist bulky carbamates groups close to these C=O groups. Self-assembly of ionic pairs of ammonium groups and carbamate anions leads to cross-linking of ε-PL.     

FTY720 Inhibits Expansion of Breast Cancer Stem Cells via PP2A Activation

Growing evidence suggests that breast cancer originates from a minor population of cancer cells termed cancer stem cells (CSCs), which can be identified by aldehyde dehydrogenase (ALDH) activity-based flow cytometry analysis. However, novel therapeutic drugs for the eradication of CSCs have not been discovered yet. Recently, drug repositioning, which finds new medical uses from existing drugs, has been expected to facilitate drug discovery. We have previously reported that sphingosine kinase 1 (SphK1) induced proliferation of breast CSCs. In the present study, we focused on the immunosuppressive agent FTY720 (also known as fingolimod or Gilenya), since FTY720 is known to be an inhibitor of SphK1. We found that FTY720 blocked both proliferation of ALDH-positive cells and formation of mammospheres. In addition, we showed that FTY720 reduced the expression of stem cell markers such as Oct3/4, Sox2 and Nanog via upregulation of protein phosphatase 2A (PP2A). These results suggest that FTY720 is an effective drug for breast CSCs in vitro.     

Simulated microgravity triggers characteristic morphology and stress response in Saccharomyces cerevisiae

Reduction of gravity results in changes in gene expression and morphology in the budding yeast Saccharomyces cerevisiae. We studied the genes responsible for the morphological changes induced by simulated microgravity (SMG) using the yeast morphology data. We comprehensively captured the features of the morphological changes in yeast cells cultured in SMG with CalMorph, a high-throughput image-processing system. Statistical analysis revealed that 95 of 501 morphological traits were significantly affected, which included changes in bud direction, the ratio of daughter to mother cell size, the random daughter cell shape, the large mother cell size, bright nuclei in the M phase, and the decrease in angle between two nuclei. We identified downregulated genes that impacted the morphological changes in conditions of SMG by focusing on each of the morphological features individually. Gene Ontology (GO)-enrichment analysis indicated that morphological changes under conditions of SMG were caused by cooperative downregulation of 103 genes annotated to six GO terms, which included cytoplasmic ribonucleoprotein granule, RNA elongation, mitotic cell cycle phase transition, nucleocytoplasmic transport, protein–DNA complex subunit organization, and RNA localization. P-body formation was also promoted under conditions of SMG. These results suggest that cooperative downregulation of multiple genes occurs in conditions of SMG.     

Investigation of meshing phenomenon of hypoid gears with different offsets via high response infrared video thermography

Forschung im Ingenieurwesen - Hypoid gears are widely used in automobile differentials. Furthermore, it is well known that the efficiency of hypoid gears is lower than that of other gears due to...     

Single image dehazing through improved atmospheric light estimation

Image contrast enhancement for outdoor vision is important for smart car auxiliary transport systems. The video frames captured in poor weather conditions are often characterized by poor visibility. Most image dehazing algorithms consider to use a hard threshold assumptions or user input to estimate atmospheric light. However, the brightest pixels sometimes are objects such as car lights or streetlights, especially for smart car auxiliary transport systems. Simply using a hard threshold may cause a wrong estimation. In this paper, we propose a single optimized image dehazing method that estimates atmospheric light efficiently and removes haze through the estimation of a semi-globally adaptive filter. The enhanced images are characterized with little noise and good exposure in dark regions. The textures and edges of the processed images are also enhanced significantly.