Single-shot digital holography separating the real and imaginary parts of a signal beam in the rhombic region of the Fourier plane

Optical Review - We propose a new single-shot digital holography that measures the complex amplitude high precisely using a single image sensor. In this technology, a signal beam passes through a...     

An incremental theory of large strain and large displacement problems and its finite element formulation

Summary This paper is concerned with the development of an incremental finite'element theory for the large strain and the large displacement problems, referred to the current configuration of the body. Using the convected coordinate system which is embedded in the body, the incremental representations of strain and stress tensors and the energy relations are presented, and then the general procedure to construct the so-called element stiffness matrix in incremental form is considered. The finite element formulation is developed for a typical constitutive relation and it is shown that some correction matrices, some of which have been omitted in the previous works, are to be added to the element stiffness matrix. Finally the method to assemble the equations of the element to the global system is discussed and a simple finite element model satisfying the compatibility condition is presented.The finite element theory developed in this paper is able to be extended to the problems for the general thermodynamical process of a broad class of nonlinear materials.

---

Übersicht Mit Hilfe der Methode der finiten Elemente wird eineZuwachstheorie zurBehandlung von Problemen mit endlicher Verformung abgeleitet. Dabei wird ein im Körper eingebettetes, der momentanen Form angepaßtes Bezugssystem verwendet. Es werden Ausdrücke für die Energie sowie für die Änderungen der Spannungs- und Verformungs-Tensoren abgeleitet und es wird ein Verfahren zur Konstruktion der Steifigkeitsmatrix für ein Element angegeben. Ein typisches Stoffgesetz wird dabei zugrundegelegt. Dabei zeigt es sich, daß einige in früheren Arbeiten vernachlässigte Korrektur-Matrizen zu der Steifigkeits-Matrix des Elementes hinzugefügt werden müssen. Die Möglichkeiten der Zusammenfassung der für die Elemente geltenden Gleichungen zu einem globalen Gleichungssystem werden diskutiert und es wird ein den Verträglichkeitsbedingungen genügendes Elemente-Modell angegeben.Das angegebene Verfahren kann für allgemeine thermodynamische Prozesse in einer breiten Klasse nichtlinearer Materialien erweitert werden.

     

Hydrogen Production from a Methanol–Water Solution Catalyzed by an Anionic Iridium Complex Bearing a Functional Bipyridonate Ligand under Weakly Basic Conditions

An efficient catalytic system for the production of hydrogen from a methanol–water solution has been developed using a new anionic iridium complex bearing a functional bipyridonate ligand as a catalyst. This system can be operated under mild conditions [weakly basic solution (0.046 mol L^?1 NaOH) below 100 °C] without the use of an additional organic solvent. Long‐term continuous hydrogen production from a methanol–water solution catalyzed by the anionic iridium complex was also achieved.     

A simultaneous space sampling method for DNA fraction collection using a comb structure in microfluidic devices

Fraction collection of selected components from a complex mixture plays a critical role in biomedical research, environmental analysis, and biotechnology. Here, we introduce a novel electrophoretic chip device based on a signal processing theorem that allows simultaneous space sampling for fractionation of ssDNA target fragments. Ten parallel extraction channels, which covered 1.5-mm-long sampling ranges, were used to facilitate the capturing of fast-moving fragments. Furthermore, the space sampling extraction made it possible to acquire pure collection, even from partly overlapping fragments that had been insufficiently separated after a short electrophoretic run. Fragments of 180, 181, and 182 bases were simultaneously collected, and then the recovered DNA was PCR amplified and assessed by CE analysis. The 181-base target was shown to be isolated in a 70-mm-long separation length within 10 min, in contrast to the >50 min required for the 300-mm-long separation channel in our previous study. This method provides effective combination of time and space, which is a breakthrough in the traditional concept of fraction collection on a chip.     

Regulation of cellular responses to macroporous inorganic films prepared by the inverse-opal method

Regenerative medicine for repairing damaged body tissues has recently become critically important. Cell culture scaffolds are required for the control of cell attachment, proliferation, and differentiation in in vitro cell cultures. A new strategy to control cell adhesion, morphology, and proliferation was developed by culturing mouse osteoblast-like MC3T3-E1 cells on novel cell culture scaffolds fabricated using ordered nanometer-sized pores (100, 300, 500, and 1000 nm). Results of this study indicate that after 72 h of incubation, the number of cells cultured on a silica film with a pore size of 1000 nm was similar to or slightly lower than that cultured on a non-porous control silica film. Films with 100-500 nm pore sizes, however, resulted in the cell growth inhibition. Morphology of the cultured cells revealed increased elongation and the formation of actin stress fibers was virtually absent on macroporous silica films with 100-500 nm pore size. Vinculin molecules expressed in cells cultured on the non-porous silica films showed many clear focal adhesions, whereas focal contacts were insufficiently formed in cells cultured on macroporous films. The influence of hydroxyapatite (HAp) and alumina scaffolds on the behavior of MC3T3-E1 cells was also evaluated. The proliferation rate of MC3T3-E1 cells cultured on HAp films with 1000 nm pore size was increased to approximately 20% above than that obtained of cells cultured on non-porous HAp films. These results demonstrate that the pore size and constituents of films play a role in controlling the morphology and proliferation rate of MC3T3-E1 cells.     

On-chip fraction collection for multiple selected ssDNA fragments using isolated extraction channels

High efficiency and high-purity fraction collection is highly sought in analysis of fragments-of-interest from selective polymerase chain reaction (PCR) products generated by High Coverage Gene Expression Profiling (HiCEP) methods. Here we demonstrate a new electrophoretic chip device enabling automatic high-efficient fractionation of multiple ssDNA target fragments during a run of separation. We used thoroughly isolated extraction channels for each selected target to reduce the risk of cross-contamination between targets due to cross-talk of extraction channels. Fragments of 35, 108 and 138 b, were successfully isolated, then the recovery was PCR-amplified and assessed by capillary electrophoresis (CE) analysis. Total impurity level of the targets due to unwanted fragments of 0.7%, 2% and 6% respectively, was estimated. Difficulties in collecting multiple target factions are due to band diffusion and DNA adsorption to the walls for the fragments in the separation channel, which is generated by transferring the DNA target fraction from the extraction section to the target reservoir. Therefore, we have carefully measured band broadening and analyzed its influence on the separation resolution due to the delay.     

Chromophores of the green fluorescent protein studied in the gas phase

Absorption of gas-phase biomolecules has been studied at the heavy-ion storage ring ELISA. Here we discuss the absorption characteristics of the chromophores of the Green Fluorescent Protein (GFP). The gas-phase absorption maximum of the deprotonated chromophore (anion form) is at 479 nm. This is almost identical to one of the two absorption maxima of the protein, being at 477 nm, which is ascribed to a deprotonated chromophore in the protein. The protonated chromophore (cation form) has a maximum at 406 nm in the gas phase. We compare the gas-phase results with absorption profiles of GFP and chromophores in liquids, and argue that the absorption characteristics of GFP are mainly ascribed to intrinsic chemical properties of the chromophore. Evidently, the special β-can structure of GFP provides shielding of the chromophore from the surroundings without significantly changing the electronic structure of the chromophore through interactions with amino acid side chains. Received 28 December 2001 Published online 13 September 2002     

Delayed ionisation of C70

A delayed ionisation experiment has been carried out on laser excited C₇₀ molecules. Ions and electrons are detected in coincidence to distinguish the ionisation of C₇₀ from that of C₆₈ molecules created by the dominant process, emission of C₂. From the time dependence of the C₇₀⁺ yield and the ratio to the C₆₈⁺ yield, we can deduce both the dissociation energy, E_d = 9.7 ±0.3 eV, and the pre–exponential factor, A_d = 1.7 ×10²⁰ s^-1, in the Arrhenius decay law for C₂ emission. The power of photon emission from neutral C₇₀ is also determined.