Light optical deformation measurements in microbars with nanometer resolution

 In a microsample tensile test the deformation of the testing region is observed with a light microscope. Using a new vision algorithm, elongations are determined with nanometer resolution. The image analysis system operates with adaptive least squares correlation and contains a diagnostic tool which provides information about the computational precision and determinability of the parameters to be estimated. Various tests are performed to verify the reliability and sensitivity of the presented method and to show its potential in the field of micromechanics. Received: 18 August 1995/Accepted: 20 December 1995     

The treatment of older adult patients with acute myeloid leukemia by triple infusion chemotherapy

This retrospective study analyzed 202 toe-to-hand transplants performed over the last 20 years at the Davies Medical Center, San Francisco (USA). The overall success rate was 97%. Toe transplants for finger reconstruction yielded optimal functional and cosmetic results due to their anatomical similarity to fingers. The great toe was preferably used for thumb reconstruction, whereas the other toes were used for reconstruction of the long fingers. Early reconstructions, multiple simultaneous toe transplants, and interventions combining toe transplantation with free flaps seemed to be advantageous because of shorter rehabilitation and comparable results.     

Light optical deformation measurements in microbars with nanometer resolution

In a microsample tensile test the deformation of the testing region is observed with a light microscope. Using a new vision algorithm, elongations are determined with nanometer resolution. The image analysis system operates with adaptive least squares correlation and contains a diagnostic tool which provides information about the computational precision and determinability of the parameters to be estimated. Various tests are performed to verify the reliability and sensitivity of the presented method and to show its potential in the field of micromechanics. This paper was not presented at the International Conference on High Aspect-Ratio Microstructure Technology HARMST '95 in July 1995.     

Experimental determination of mechanical properties of Ni and Ni-Fe microbars

In this study, nickel and nickel-iron alloy microsamples produced using the LIGA technique are investigated. With vibration tests and tensile tests, design parameters such as Young’s modulus, elastic limit, and failure stress are determined. A new microsample tensile test apparatus is presented, in which forces and elongation are separately measured with very high accuracy. The comparison between the Young’s modulus which is determined with vibration experiments and the Young’s modulus derived from tensile tests ensures the reliability of the measurements presented. The error sources are analysed with the help of finite element models and the uncertainty in determining the Young’s modulus is calculated. The strength values measured for LIGA specimens are about 3 times higher than for comparable macroscopic specimens. This paper was not presented at the International Conference of High Aspect-Ratio Microstructure Technology HARMST ’95 in July 1995.     

Application of LC and LC-MS to the analysis of melatonin and serotonin in edible plants

Melatonin is a neurohormone produced by the pineal gland of animals. Serotonin is a monoamine neurotransmitter and one of the precursors of melatonin biosynthesis. These two indoleamines have recently been reported to have widespread occurrence in many edible plants. Consuming foodstuffs containing melatonin and serotonin could raise their physiologic concentrations in blood and enhance human health. Literature concerning analytical methods suitable for determination of melatonin and serotonin in edible plants is limited, although several liquid chromatographic (LC) techniques have been used for their quantification. Liquid chromatography-mass spectrometry (LC-MS) methods combine selectivity, sensitivity, and high precision, and enable the simultaneous determination of melatonin and serotonin. This work reviews LC and LC-MS techniques used to determine melatonin and serotonin, and the available data on melatonin and serotonin levels in edible plants.     

Mullite-Type Structures in the Systems Al2O3–Me2O (Me = Na, K) and Al2O3–B2O3

A morphous solids belonging to the systems Al₂O₃–Me₂O (Me = Na, K) and Al₂O₃–B₂O₃ were prepared by nitrate decomposition, introducing boron in the form of boric acid. Crystalline metastable solids with pseudotetragonal symmetry were obtained from thermal treatment at 850° to 900°C for the compositions Al₆Me_xO_{(9+0.5 x )} ( x ≅ 1; Me = Na, K) and Al_{6- x} B _x O₉ (1 x 3). The resultant solids were stable only within a difinite temperature range and transformed, with further treatment increases, into stable equilibrium phases. The structures of the metastable phases were examined by X-ray diffraction and Fourier transform infrared spectroscopy, and both analyses showed a mullite type of framework, inside of which the atomic coordinates were refined in the Pbam (no. 55) space group. The present results indicate that these silica-free mullite structures are stabilized by two different mechanisms: (1) interstitial occupation of bulky cations (Na⁺, K⁺) or (2) substitution of B for Al in some of the tetrahedral positions.