Steady thermal convection representing the ultimate scaling.

Nonlinear simple invariant solutions representing the ultimate scaling have been discovered to the Navier-Stokes equations for thermal convection between horizontal no-slip permeable walls with a distance [Formula: see text] and a constant temperature difference [Formula: see text]. On the permeable walls, the vertical transpiration velocity is assumed to be proportional to the local pressure fluctuations, i.e.

Nanoparticle size and 3D shape measurement by electron tomography: An Inter-Laboratory Comparison.

Electron tomography (ET) has been used for quantitative measurement of shape and size of objects in three dimensions (3D) for many years. However, systematic investigation of repeatability and reproducibility of ET has not been evaluated in detail. To assess the reproducibility and repeatability of a protocol for measuring size and three-dimensional (3D) shape parameters for nanoparticles (NPs) by ET, an inter-laboratory comparison (ILC) has been performed.

Fast and accurate defocus modulation for improved tunability of cryo-EM experiments.

Current data collection strategies in electron cryo-microscopy (cryo-EM) record multiframe movies with static optical settings. This limits the number of adjustable parameters that can be used to optimize the experiment. Here, a method for fast and accurate defocus (FADE) modulation during movie acquisition is proposed.

Hole free phase plate tomography for materials sciences samples.

We report, for the first time, the three dimensional reconstruction (3D) of a transistor from a microprocessor chip and roughness of molecular electronic junction obtained by electron tomography with Hole Free Phase Plate (HFPP) imaging. The HFPP appears to enhance contrast between inorganic materials and also increase the visibility of interfaces between different materials. We demonstrate that the degree of enhancement varies depending on material and thickness of the samples using experimental and simulation data.

Transglycosylation Activity of Catalytic Domain Mutant of Endo-1,3-β-glucanase from Cellulosimicrobium cellulans.

Background: Oligosaccharides are of great value in drug discovery programs which address a wide range of therapeutic strategies in medical specialties. However, owing to difficulties in oligosaccharide synthesis by conventional methods, oligosaccharide assembly using enzymes has been explored. The transglycosylases have been demonstrated to be effective for the oligosaccharide synthesis.

Practical Experience with Hole-Free Phase Plates for Cryo Electron Microscopy.

Phase plate (PP) imaging has proven to be valuable in transmission cryo electron microscopy of unstained, native-state biological specimens. Many PP types have been described, however until the recent implementation of the "hole-free" phase plate (HFPP), imaging has been challenging. We found the HFPP to be simple to construct and to set up in the transmission electron microscopy, but care in implementing automated data collection is needed.

Posttranslationally caused bioluminescence burst of the Escherichia coli luciferase reporter strain.

We continuously monitored bioluminescence from a wild-type reporter strain of Escherichia coli (lacp::luc+/WT), which carries the promoter of the lac operon (lacp) fused with the firefly luciferase gene (luc+). This strain showed a bioluminescence burst when shifted into the stationary growth phase. Bioluminescence profiles of other wild-type reporter strains (rpsPp::luc+ and argAp::luc+) and gene-deletion reporter strains (lacp::luc+/crp- and lacp::luc+/lacI-) indicate that transcriptional regulation is not responsible for generation of the burst.

Firefly luciferase as the reporter for transcriptional response to the environment in Escherichia coli.

We demonstrate that firefly luciferase is a good reporter in Escherichia coli for transcription dynamics in response to the environment. E. coli strains, carrying a fusion of the promoter of the ycgZ gene and the coding region of the luciferase gene, showed transient bioluminescence on receiving blue light.

Transmission electron microtomography in soft materials.

This review summarizes the recent advances in three-dimensional (3D) imaging techniques and their application to polymer nanostructures, for example, microphase-separated structures of block copolymers. We place particular emphasis on the method of transmission electron microtomography (electron tomography for short; hereafter abbreviated as ET). As a result of recent developments in ET, truly quantitative 3D images of polymer nanostructures can now be obtained with subnanometer resolution.

Effects of various asparagus production methods on rutin and protodioscin contents in spears and cladophylls.

The purpose of this study was to clarify the relationship between various cultivation conditions and the amounts of the rutin (RT) and protodioscin (PD) in asparagus spears. Green and white spears were grown in open culture and under two different blanching conditions. Although RT was detected only in the green spears, PD was detected mainly in white spears produced by covering with soil.

Isopimarane diterpene glycosides, apoptosis inducers, obtained from fruiting bodies of the ascomycete Xylaria polymorpha.

The methanol extract of fruiting bodies of the ascomycete Xylaria polymorpha afforded three isopimarane diterpene glycosides, namely, 16-alpha-D-mannopyranosyloxyisopimar-7-en-19-oic acid (1), 15-hydroxy-16-alpha-D-mannopyranosyloxyisopimar-7-en-19-oic acid (2), and 16-alpha-D-glucopyranosyloxyisopimar-7-en-19-oic acid (3). Their structures were determined by spectroscopic methods and by single-crystal X-ray analysis. They showed cytotoxicity against human cancer cell lines and exhibited IC50 values ranging from 71 to 607 microM.

Major anthocyanins from purple asparagus (Asparagus officinalis).

Two major anthocyanins (A1 and A2) were isolated from peels of the spears of Asparagus officinalis cv. Purple Passion. They were purified by column, paper and high-performance liquid chromatographic separations, and their structures were elucidated by high-resolution Fourier transform ion cyclotron resonance mass spectrometry (HR-FT-ICR MS), 1H, 13C and two-dimensional NMR spectroscopic analyses and either acid or alkaline hydrolysis, respectively.

Direct probe of the shape resonance mechanism in 2sigma(g)-shell photoionization of the N2 molecule.

Angular distributions of photoelectrons from a 2sigma(g) shell of fixed-in-space N2 molecules have been measured for left- and right-elliptically polarized and for linearly polarized light at several photon energies in the region of sigma(*) shape resonance. That allowed the determination of a set of dipole matrix elements and phase shift differences characterizing the process. These data clearly show the enhancement of the fsigma(u) partial cross section in the resonance simultaneously with an abrupt increase of the corresponding phase shift by pi, which is the first experimental demonstration of the nature of the sigma(*) shape resonance in homonuclear diatomic molecules.

Application of nitrifying and denitrifying processes to waste management of aquatic life support in space.

Since a biological filter with nitrifying bacteria was firstly applied to aquatic animal experiments in IML-2 mission, the reactor system has been further studied to combine both nitrifying and denitrifying reactions under aerobic environment allowing an efficient removal of inorganic nitrogen from animal wastes. The isolated denitrifying bacteria had an activity under aerobic condition with rice straw providing a metabolic carbon source for the reaction. The advantage of the aerobic biological filter having both nitrifying and denitrifying activities may allow to reduce the size of the life support system and also for its manageability.

Manifestation of many-electron correlations in photoionization of the K shell of N2.

It is demonstrated theoretically in the random phase approximation (RPA) that due to the intershell many-electron correlations the sigma(*) shape resonance in the photoionization of K shells of the N2 molecule appears not only in the 1sigma(g)-->varepsilonsigma(u) channel as it was believed earlier on the basis of single particle calculations, but in both 1sigma(g)-->varepsilonsigma(u) and 1sigma(u)-->varepsilonsigma(g) channels. As a confirmation of this phenomenon we show that the experimental angular distributions of photoelectrons ejected from fixed-in-space N2 molecules can be reproduced theoretically only after taking into account many-electron correlations.

Photoelectron angular distributions from O K shell of oriented CO molecules: A critical comparison between theory and experiment.

The dynamical information (ten dipole matrix elements and eight phase differences) has been deduced from the measured angular distributions of photoelectrons from O K shell of oriented CO molecules near the ionization threshold in the region of a sigma(*) shape resonance. Light polarization parallel and perpendicular to the molecular axis has been used. An important contribution of six lsigma partial waves with 0 View Article and Find Full Text PDF

Potent inhibitors of histamine release, two novel triterpenoids from the Okinawan marine sponge Penares incrustans.

Two novel triterpenoids with an unusual 14-carboxyl group, penasterone [1] and acetylpenasterol [2], were isolated from the Okinawan marine sponge Penares incrustans. The structures of 1 and 2 were established mainly on the basis of nmr spectroscopic data. The relative stereochemistry of 1 was confirmed by single-crystal X-ray diffraction analysis.