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We have developed a direct comparison between microwave and optical frequencies by an ultra-fast mode-locked laser comb broadened with a photonic-crystal fiber. Control of the comb frequency to improve the measurement precision is presented.

It is well known that high temperature superconducting (HTS) bulk can be levitated stably on a permanent magnet. A new type HTS bulk linear synchronous motor (LSM) theory is proposed by authors which is based on an idea of considering the pinning force as a synchronizing one in using current-carrying-armature-winding instead of permanent magnets. So, to design HTS LSM, before its manufacture, it is necessary to do numerical evaluation. This paper proposes a new method which can treat HTS bulk as a permanent magnet with the same magnetization on finite element method (FEM). The proposed method is used under the assumption that the penetration thickness of the magnetic field applied parallel to side surface of HTS bulk is the same as that of HTS slab. The thrust and normal forces in the HTS LSM model are calculated by the FEM capable of modeling HTS bulk with flux penetration. (2 pages)

High-resolution long-distance measurements have been required in many application fields such as optical geodesy, shape measurement of parabola antennae, and sensors. Conventionally, several methods have been used for length measurements. Optical length-measuring interferometer and time-of-flight measurement of optical pulses have been used for high-resolution measurements, however they are not suitable for long distances, because they require continuous scanning of the optical path as a reference. On the other hand, phase measurement of a sinusoidally modulated cw optical wave has been used for long distance measurement because real-time measurement without a scanning reference is possible [1]. In this method, either high-resolution phase meter or high-frequency modulation is required to realize high resolution in the distance measurement. Recently, high-frequency cw modulation as 28 GHz has been reported [2], but there was an inevitable problem that caused a large cyclic error, which was independent of the distance originating from electric and optical crosstalk due to an external modulator with a complex setup. We have developed an optical distance meter based on phase measurement of an intermode beat of a frequency comb using a mode-locked femtosecond laser [3]. It does not require an external modulator, thus we can significantly suppress the cyclic error and, moreover, the setup is simple, which is important for practical application. Furthermore, the femtosecond distance meter has marked advantages over cw methods in that it is suitable for multicolor measurement and is less sensitive to sharp absorption lines in air. These qualities are important for reliability and accuracy. In the previous study, we achieved 50 um resolution at a 240 m distance using 1 GHz beat frequency. Without a modulator, it is easy to utilize high frequency by simply selecting one of the beat components in the broad and stable frequency comb. In this study, we achieved ultrahigh one-micrometer resolution in the femtosecond distance meter by using up to 10 GHz components of beat frequencies.

We demonstrate microscopic time-resolved two-dimensional (2D) imaging that is based on a femtosecond amplifying optical Kerr gate (fs-amp OKG). The contribution of the optical nonlinear effects to the transverse imaging performance and the limit of the transverse resolving power are investigated. The optical Kerr effect in the excited state with amplification, used in the fs-amp OKG, does not deteriorate the quality of the time-resolved image at transverse resolutions up to at least 5.5 microm. We obtain a femtosecond-time-resolved 2D image of a microscopic object with a transverse resolution of 1.7 microm.

Single-switch bridge leg with a snubber energy recovery feature is studied for buck rectifier applications. To recover the snubber energy, two snubber capacitors are arranged across an active power device. An example of a single-phase rectifier applying a proposed bridge leg is implemented to investigate the operation. The experimental results under the sinusoidal pulse-width modulation confirm that the rectifier can recover the snubber energy and the input current is almost wave-shaped sinusoidally with a near-unity power factor.

A unique absolute length measurement method is proposed and demonstrated for the first time. Since it takes advantage of both the high-accuracy measurement capability of a pulse train interference method and the ability of a two-color method to compensate for environmental changes, the present method is expected to be useful for high-precision length measurement for not only the purposes of laboratory science but also for satisfying the requirements of industry. A length measurement was performed to demonstrate the feasibility of the proposed method.

Metastasis is a major cause of death in cancer patients and involves a multistep process including detachment of cancer cells from a primary cancer, invasion of surrounding tissue, spread through circulation, re-invasion and proliferation in distant organs. KiSS-1 is a human metastasis suppressor gene1, that suppresses metastases of human melanomas2 and breast carcinomas3 without affecting tumorigenicity. However, its gene product and functional mechanisms have not been elucidated. Here we show that KiSS-1 (refs 1, 4) encodes a carboxy-terminally amidated peptide with 54 amino-acid residues, which we have isolated from human placenta as the endogenous ligand of an orphan G-protein-coupled receptor (hOT7T175) and have named ‘metastin’. Metastin inhibits chemotaxis and invasion of hOT7T175-transfected CHO cells in vitro and attenuates pulmonary metastasis of hOT7T175-transfected B16-BL6 melanomas in vivo. The results suggest possible mechanisms of action for KiSS-1 and a potential new therapeutic approach.

The low-coherence interferometric technique is proposed for the in-situ measurement of the refractive index of dispersive samples with high accuracy. A tandem configuration of a Michelson interferometer and a triangular interferometer is used to compensate for the chirping effect which results from the broad spectrum of the light source. Thick samples can be successfully measured with the low- coherence interferometer, therefore the relative accuracy of the refractive index can be improved.

We have established four I2-stabilized Nd:YAG lasers to verify the frequency reproducibility of the lasers. The observed square root Allan variance of the four lasers was between 1 to approximately 4 X 10-14 depending on the obtained signal-to-noise ratio of the spectra, when the integration time is larger than 300 s. The observed frequency reproducibility of each laser was ranged from 9.1 X 10-14 approximately 1.5 X 10-13 (corresponding to frequency uncertainties of +/- 51 approximately 87 Hz). Frequency reproducibility of a group of lasers (four NRLM lasers) has been evaluated to be 8.2 X 10-13 (corresponding to a frequency uncertainty of +/- 640 Hz). One of the four NRLM lasers is a compact I2- stabilized Nd:YAG laser which is suitable to be transported to other laboratories for international frequency comparisons. Using this portable laser, we have accomplished frequency comparisons of Nd:YAG lasers between several metrological institutes in different countries. The absolute optical frequencies of the NRLM lasers were determined with an uncertainty of about 1.5 kHz by the frequency comparison between the NRLM and the JILA (formerly the Joint Institute for Laboratory of Astrophysics), Boulder, CO.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The use of an optical frequency comb generated by an ultrafast mode-locked laser has been realized as a promising method of the direct comparison between microwave and optical frequencies. We are currently investigating frequency control of a chirped-mirror-dispersion-controlled mode-locked Ti:Al2O3 laser. We stabilized the pulse repetition rate frep to a rf synthesizer locked to a cesium (Cs) clock to the Allan deviation of 4 X 10-12 in 1 s. We found that the position of the crystal, rotation of the chirped mirrors, and change of the pump-laser power can be used in controlling the carrier-envelope offset frequency fCEO. We extended the span of the comb to over one octave, i.e., from 530 nm to 1190 nm, at -20 dB using a photonic-crystal fiber made at the University of Bath. We are currently trying to measure the frequency of an iodine-stabilized Nd:YAG laser using a floating ruler of a f:2f frequency interval chain. We detected the self-referencing beat between the fundamental and second- harmonic frequencies of the comb, which will enable further precise comparison between microwave and optical frequencies through the control of the fCEO.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A1/A2 noradrenergic neurons in the medulla oblongata are well known to mediate stress signals in the central nervous system. Stress activates A1/A2 noradrenergic neurons, and then noradrenaline (NA) stimulates ACTH secretion through hypothalamic CRH. On the other hand, PRL-releasing peptide (PrRP) was recently isolated and was found to be produced by some A1/A2 neurons and the dorsomedial hypothalamic nucleus. We previously demonstrated that PrRP neurons make synapse-like contact with hypothalamic CRH neurons. In fact, we demonstrated that the central administration of PrRP stimulates CRH-mediated ACTH secretion. Furthermore, it has been reported that PrRP neurons in A1/A2 cell groups are colocalized with tyrosine hydroxylase (TH), which is known as the marker enzyme of catecholaminergic neurons. These data strongly suggest that PrRP is related to stress-responsive signal transduction, and PrRP and NA cooperatively modulate the hypothalamo-pituitary-adrenal axis. We therefore examined the effect of water immersion-restraint stress on c-Fos protein accumulation in PrRP- and TH-immunoreactive neurons. The synergistic effects of PrRP and NA on plasma ACTH elevation were also examined. The results clearly showed that c-Fos protein accumulation dramatically increased in the nuclei of A1/A2 and dorsomedial hypothalamic nucleus PrRP neurons. In addition, it was revealed that c-Fos protein was specifically expressed in the PrRP/TH double positive cells in the A1/A2 cell groups. We also demonstrated that the central administration of PrRP and NA in combination at subactive (noneffective) doses clearly induced plasma ACTH elevation. Here we report that PrRP is a novel and important mediator of the hypothalamo-pituitary-adrenal axis for the stress response.

Summary form only given. We propose a new method of direct group-refractive-index measurement using a repetition rate of a stabilized femtosecond pulse laser. For conventional phase-refractive-index measurement, the comparison between an optical path through air and an equivalent path in vacuum is necessary. In contrast, our new method utilizes an interferometer between adjacent femtosecond pulses in a mode-locked train without the necessity of a long reference arm in vacuum, which makes the setup simple. Tunable and stabilized repetition rate of a femtosecond pulse laser gives a high-accuracy in the measurement.

This paper presents a model of a three-phase contactless power transfer system with short gap between the primary and secondary armatures. The model of the system is derived from typical equivalent circuit equations of a three-phase induction motor. On the basis of this model, robustness of the system for the horizontal displacement between the primary and secondary armatures is proved.

A high-accuracy length-measuring two-colour interferometer for the compensation of the refractive index of air is described. It counts two types of interference fringes which are in phase quadrature by means of a lambda /8 plate. The light source is a diode laser pumped YAG laser of about 40 mW output power; its second harmonic wave is generated by a KTiOPO4 (KTP) crystal. The resolution in determining the refractive index of air is improved by averaging the numbers of the interference fringes counted. The interferometer is evaluated to be better than 2*10-7 in accuracy.

Heterodyne white-light interferometer that uses an optical grating to shift the optical frequency of the white light is proposed. By moving the optical grating, the diffracted lights undergo the frequency shift. The dependency of diffraction angle on wavelength can be resolved by using a spherical mirror, and then heterodyne detection of white-light can be realized with the combination of the optical grating and the spherical mirrors. In practical uses, a tandem-configuration interferometer is useful. The principle was demonstrated and the effect was confirmed experimentally for the first time The surface profile of a step-like object was measured. The signal-to-noise ratio of heterodyne signal is increased by thousand times from that of homodyne signal.

Single-phase boost rectifier with snubber energy recovery feature operating under the current-mode control with a turn-on at constant clock time is studied. In this rectifier, the resonant circuit consisting of small inductor and capacitor is added in DC circuit. The snubber energy is transferred to an additional resonant capacitor and can next be transferred to the load circuit when an insulated-gate bipolar transistor as the active power device is turned off. The experimental prototype is implemented to investigate the operation. The experimental results confirm that the proposed snubber energy recovery scheme has the feasibility.

Single-phase boost rectifier with parallel-input/series-output structure is studied by the simulation. In this rectifier, the output capacitor is charged by the series connection of intermediate capacitors arranged in parallel. To improve the input current distortion just after a zero-crossing, moreover, the snubber capacitor voltage is superimposed on the supply by using the snubber energy recovery switch cell. The simulated results confirm that the low-order input current harmonics can be reduced under the operating condition with the output voltage almost twice the peak supply voltage.

The prolactin-releasing peptide (PrRP) is a novel hypothalamic peptide that has been purified as a ligand of an orphan receptor which is expressed in pituitary cells, and is known to stimulate prolactin release both in vitro and in vivo. We previously determined the immunocytochemical localization of PrRP neurons in the rat brain and our results suggest that PrRP takes part in a variety of brain functions. Additionally, in rats we have demonstrated the synaptic contact of PrRP neurons with oxytocin cell bodies in the paraventricular hypothalamic nucleus (PVH) and supraoptic nucleus (SON). This observation indicates that PrRP may regulate oxytocin secretion. In the present study, we performed intra-cerebroventricular administration of PrRP to conscious rats, and examined the effect of PrRP on the plasma levels of oxytocin and vasopressin. Our results show that central administration of PrRP increased the plasma oxytocin and vasopressin levels in female rats, but in male rats only oxytocin was increased. These results suggest that the PrRP acts as a neuro-modulator of the function of magnocellular neurons, especially oxytocin neurons, in the brain.

A novel low-coherence interferometer has been developed, based on the heterodyne technique for highly accurate and sensitive positioning of a three-dimensional (3-D) object, which uses two acousto-optic modulators (AOM's) and two spherical reflecting mirrors in a Michelson interferometer. By using this technique in a tandem interferometer, the profiles of diffusing and mirror-likes surfaces of the 3-D objects are measured with a high accuracy of 50 nm from the heterodyne signals of 200 kHz.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A hypothalamic peptide that stimulates PRL release has recently been found as a ligand of an orphan receptor and named PRL-releasing peptide (PrRP). PrRP and its receptor were mainly detected in the hypothalamus and pituitary gland, respectively. Its characteristics suggested PrRP to be a novel hypophysiotropic peptide that stimulates the anterior pituitary PRL cell; however, this remained to be confirmed morphologically. We therefore performed an immunocytochemical study to locate PrRP in the rat brain using the region-specific monoclonal antibodies, P2L-1C and P2L-1T, which recognize the C-terminal and the internal sequence of PrRP, respectively. Our results clearly show that dense immunoreactive nerve fiber networks are present in the paraventricular hypothalamic nucleus, supraoptic nucleus, paratenial thalamic nucleus, basolateral amygdaloid nucleus, and bed nucleus of the stria terminalis. A small number of PrRP nerve fibers was also observed in the neural lobe of the hypophysis. However, no immunopositive fiber was observed in the external region of the median eminence, which is known to be the release site of the classical hypophysiotropic hormones. Also, the distribution of PrRP was not changed during the estrous cycle. We therefore concluded that PrRP probably differs from classical hypothalamic releasing hormones. We found the immunoreactive cell bodies to be mainly in the caudal portion of the dorsomedial hypothalamic nucleus and solitary nucleus. A double immunocytochemical procedure revealed that some PrRP-positive neurons showed synaptic contact with oxytocin-positive cell bodies in the paraventricular hypothalamic nucleus, which suggests that PrRP regulates the function of oxytocin neurons. This is the first report to demonstrate the localization of the novel hypothalamic peptide, PrRP, and we therefore suggest that it takes part in a variety of brain functions. However, it is not yet known how PrRP is transported to the pituitary gland, which is the site that contains the greatest concentration of receptors to this new peptide. Therefore, additional work will be required to resolve this discrepancy between ligand and receptor site location.

We have developed a laser interferometer to calibrate gauge block utilizing 2 lasers, 633 nm He-Ne and 1,064 nm Nd:YAG. At only 633 nm of wavelength, several kinds of practical He- Ne lasers have been developed and manufactured, while there is not practical laser light source for interferometer other than at 633 nm. To realize practical light source in addition to 633 nm, we stabilized the wavelength of 1,064 nm Nd:YAG laser, utilizing linear absorption of iodine at 532 nm. The iodine cell was inserted between two non linear crystals for second harmonic generation and first derivative signal was generated by dispersion effect near the absorption line of iodine, without electric circuit for modulation or for phase sensitive detection. Gauge blocks were measured with the two wavelengths of 633 and 1,064 nm. The fringe pattern was detected by CCD camera and the length was estimated by excess fraction method. It is easy to determine the integer part of the fringe order, since the wavelength difference between these two is large and the wavelength ratio is not expressed by a simple combination on integers. The results agreed with those obtained by conventional method with 198Hg isotope lamp.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The domestic round-robin testing for interferometric length measurements of gauge blocks was initiated in 1960 in Japan, to evaluate and also to improve the proficiency of calibration laboratories. It had been arranged by the National Research Laboratory of Metrology (NRLM) and Japan Precision Measuring Instrument Association 16 times prior to 1992. A 100 mm gauge block was used as the test object on each occasion and measurement result of the NRLM was used as the reference value. When the difference between the result of each laboratory and the NRLM was larger than 30 nm, the laboratory repeated the measurement and the reason for the discrepancy was investigated. About 10 laboratories, including those of local governments, private companies and semigovernment organizations, participated regularly and many of them maintained their proficiency in the measurement of gauge blocks.

Hypothalamic peptide hormones regulate the secretion of most of the anterior pituitary hormones, that is, growth hormone, follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone and adrenocorticotropin. These peptides do not regulate the secretion of prolactin, at least in a specific manner, however. The peptides act through specific receptors, which are referred to as seven-transmembrane-domain receptors or G-protein-coupled receptors. Although prolactin is important in pregnancy and lactation in mammals, and is involved in the development of the mammary glands and the promotion of milk synthesis, a specific prolactin-releasing hormone has remained unknown. Here we identify a potent candidate for such a hormone. We first proposed that there may still be unknown peptide hormone factors that control pituitary function through seven-transmembrane-domain receptors. We isolated the complementary DNA encoding an 'orphan' receptor (that is, one for which the ligand is unknown). This receptor, hGR3, is specifically expressed in the human pituitary. We then searched for the hGR3 ligand in the hypothalamus and identified a new peptide, which shares no sequence similarity with known peptides and proteins, as an endogenous ligand. We show that this ligand is a potent prolactin-releasing factor for rat anterior pituitary cells; we have therefore named this peptide prolactin-releasing peptide.

A multi-point dynamic displacement probe was developed for measuring dynamic displacement and deformation. This method uses an acousto-optic deflector (AOD) as a diffractive scanner to allow the laser beam to scan a self-focusing microlens array (SMLA), and then uses the resulting focused spot to scan the diffuse surface. The focus information contained in the laser beam reflected from the diffuse surface is then transformed into the variations in shape of spot for detection. Due to the very high scanning speed of the AOD, the relative position of many points, and thus the dynamic deformation, can be measured in near real-time. This paper describes the method's principles, accuracy, and error sources.

A scanning beam collimation (SBC) method is developed for measuring dynamic angle variations in which an acousto-optic deflector is used as a diffractive scanner to compensate the angle variation in real time, and a position sensor is used to detect the position of the beam that is reflected from the reflector (i.e., object) to be measured. The angle variation can be measured at high speed due to the very high scanning speed available in the acousto-optic deflector. There was good agreement between the angle variation measured using the SBC method and that using a conventional electronic autocollimator. The repeatability, resolution, and linearity of the scanning beam collimation method were determined using a piezo translator to generate tilt angle; the results showing that high accuracy also can be achieved in dynamic angle variation measurement. The SBC method was applied to measure the tilt angle variation caused by the beating force of a dragonfly attached to one end of a gauge block. The results confirmed the effectiveness of this new method.

A new method has been developed to simultaneously measure the thickness and shape of a thin film, such as a dragonfly wing. The innovation in the method is the combining of a heterodyne interferometer and a laser triangulation displacement sensor into one optical system. We confirmed the accuracy of the method by measuring the displacement of a glass plate and the thickness variation generated by a rotated glass plate. The system has a relative accuracy of 1% in the shape measurement and 1.3% in the thickness variation measurement. The method was then applied to a dragonfly wing. The results indicated that the method is very effective in biomechanics studies, such as evaluating the flight performance of dragonflies. In such evaluations, it is essential to measure the high accuracy the variations in both shape and thickness of the wing simultaneously.

The study of the flight performance of a dragonfly requires a simple method to measure the torsional angle and flapping angle of a dragonfly wing during beating motion, we developed a fringe projection method in which the flapping angle and torsional angle of a dragonfly wing can be measured during beating motion using only one high-speed camera. The measured sections can be easily recognized from the number of fringes, without having to use any diffuse marks.

Three-dimensional (3-D) shape measurements have been scientifically and practically attractive and several methods have been proposed. Most of the conventional methods require either rather complex image processing or some mechanism to scan the laser beam and/or delay time.[1,2] We have proposed a new method in which simultaneous 3-D imaging is possible without the need for scanning by means of conversion between the time and color axes mediated by the chirped pulse.[3] The applicability of this method was demonstrated by measuring highly reflecting gauge blocks. In this paper, we apply the method to measure the internal structure of the transmission objects and the surface structure of the diffusing objects.

Noncontacting surface sensor based on the principle of laser triangulation has been developed for measuring the displacement of objects that have diffuse surfaces. However, (here are two major drawbacks when such a method is used for diffuse surfaces that have low reflectivity, such as a dragonfly wing. The first drawback is that the measured displacement range is limited by the poor linearity that is due to using a short focal-length lens to collect sufficient light. This problem can be understood by looking at the dashed line in Fig. 1. The second drawback is that, due to light-transfer noise inherent in every position sensor cell, reflectivity variations in the diffuse surface produce measurement errors.

A new cell line (TtT/GF) established from a murine pituitary thyrotropic tumor having characteristics similar to those of pituitary folliculo-stellate cell (FS cell) was implanted into nude mice together with cells from a rat pituitary somatotrophic tumor cell line (MtT/S) to determine whether the former enhances pituitary tumor growth. For as long as 2-3 mo after implantation, MtT/S cells implanted either alone or together with fibroblasts formed either no tumors or only very small tumors in the nude mice. In contrast, all of the nude mice that had received MtT/S cells implanted together with TtT/GF cells developed large tumors. Furthermore, the mice bearing the MtT/S and TtT/GF implants showed a significantly higher body weight and serum growth hormone level than those bearing only MtT/S cells or a combination of MtT/S cells and fibroblasts. The TtT/GF cell line itself had no tumorigenicity during the experimental period. Therefore, the TtT/GF cell line as a model of FS cells enhanced pituitary endocrine cell tumor formation. Additionally, immunocytochemistry showed that TtT/GF cells positive for glial fibrillary acidic protein (GFAP) or S-100 protein were present in the parenchymatous tissue elements or connective tissue surrounding the tumor nests. In the parenchymatous tissue, the TtT/GF cells exhibited a stellate appearance and surrounded neighboring tumor cells with their long cell processes. These results suggest that TtT/GF cells can serve as a model for pituitary FS cells, and are capable of stimulating pituitary tumor growth either by modifying the microenvironment or producing growth factors.

Novel crystalline polymer, crystalline hydrogenated poly(endo-dicyclopentadiene), was developed on the basis of the development of new cis- and iso-specific ROMP catalysts such as MoO(rac-5,5′,6,6′...

In a dual-frequency-excited parallel plate capacitively coupled plasma employing a heptafluoro-cyclo-pentene (C5HF7) gas with addition of O2 and dilution in Ar gas, highly selective etching of SiO2 at selectivities of 40 against Si3N4 and 57 against polycrystalline Si was realized. Gas phase fluorocarbon species containing H atoms such as C x HF y (x>2) played key roles in the selective deposition of thick hydrofluorocarbon films that covered the Si3N4 and polycrystalline silicon (poly-Si) surfaces and in the selective etching of SiO2 over the photoresist, SiN, and Si.

A robust fluorocarbon film was successfully deposited on a substrate at a temperature above 400 °C by the new microwave plasma-enhanced chemical vapor deposition (MWPE-CVD) method using the linear C5F8 precursor instead of a conventional cyclic C5F8 one. The fluorocarbon performed keeping the dielectric constant low as a value of 2.25 by controlling the molecular structure forming cross-linked poly(tetrafluoroethylene) (PTFE) chains with configurational carbon atoms. The novel fluorocarbon demonstrates less fluorine degassing at an elevated temperature, with high mechanical strength and without degradation of adhesion of the fluorocarbon film to SiCN and SiO x stacked films after thermal stress at 400 °C and 1 atm N2 for 1 h. Consequently, this robust fluorocarbon film is considered a promising candidate for general porous silicon materials with applications to practical integration processes as an interlayer dielectric.

A heterodyne interference system is developed for baseline measurement by using an acoustic optical modulator and an optical frequency comb stabilized by a rubidium atomic clock. Temporal coherence interference occurs at discrete spatial positions, when two pulse trains overlap. An optical delay of the interferometer with a piezoelectric transducer is created to determine the peak positions of the interference fringe patterns, and the absolute distance is obtained at a high resolution of several tens of nanometers. The experimental results at baseline distances up to 403.2 m show a high reproducibility of about 6 µm.

We developed a Fabry–Perot etalon to select high-frequency parts of repetition-frequency modes of a short pulsed, mode-locked fiber laser at the wavelength of 1.55 µm. The 2 GHz repetition-modified laser is transmitted to an unbalanced Michelson interferometer with gauge blocks wrung on a platen. Two interference fringes were generated from the gauge block and platen at different positions. The interference fringes have a temporal coherence pattern and can make positioning in space easy. The length of the gauge block was directly determined from different positions of the two interference fringes, without using the excess fractions method.

A heterodyne interference system was developed for position measurement. A stabilized optical-frequency comb is used as the laser source. The preliminary experiment to measure a distance of 22.478 m shows a drift of 1.6 μm in 20 minutes after the temperature compensation. Comparison and frequency shift experiments have been done for a distance of about 7.493 m. The experimental results show that the drift is mainly caused by environmental condition changes and the vibration of the table and floor also has some effects. It was verified that the absolute distance measurement can be realized by fringe scanning and frequency-shifting methods.

A new method for measuring vibrations using a quadrant position sensor has been developed. It allows non-contact measurement of natural frequencies of objects which are small or light and transparent. The natural frequencies in two dimensions can be received at the same time. The system consists of a laser light source, a quadrant position sensor and spectrum analyzer. The object is illuminated by divergence laser rays coming from a microscope objective. The vibration amplitudes are magnified and detected by the position sensor. By adjusting the distance between object and microscope objective or detector, the sensitivity and linearity of the system can be changed. The natural frequencies of a plastic plate were measured by this method. The experimental results agreed well with the calculation results according to the theory of material mechanics. This method is very useful in the research field of millibioflight. The natural frequencies of the dragonfly wing, which is lighter than 0.1 mg, has been measured by this method. We can determine the natural frequencies of bending and torsional deformation by using the information of two dimensions.

To understand the biosynthesis of the human ET family, three kinds of cloned cDNA for human prepro-endothelin-1 (prepro-ET-1), prepro-ET-2, and prepro-ET-3 were stably expressed in Chinese hamster ovary cells (CHO-K1). Immunoreactive (ir-) ET polypeptides in the culture media of the transformants were purified by reverse-phase high-performance liquid chromatography (HPLC) coupled with sandwich-type enzyme immunoassay (EIA). Amino acid sequencing and FAB mass spectrometry of the purified ir-ET polypeptides revealed the presence of human big ET-1 (1-38), big ET-2 (1-38), and big ET-3 (1-41)NH2 as intermediate forms. These results directly revealed the biosynthetic pathways of three human ETs at the peptide level.

Molecular forms and concentrations of endothelin (ET) family peptides in normal human plasma and urine were investigated using five different sandwich-type enzyme immunoassays (sandwich-EIAs) and reverse-phase high performance liquid chromatography (RP-HPLC). We found that immunoreactive (IR-) big ET-3 and IR-big ET-2 were the major species in both plasma and urine from normal humans. Big ET-2(1–38) was found to be the major form of IR-big ET-2 in plasma. Urinary IR-big ET-2 and plasma and urinary IR-big ET-3 were heterogeneous, and the IR-big ET-3s were larger ( M r 6,000–12,000 ) than authentic big ET-3. IR-big ET-1, IR-ET-1, and IR-ET-3 were found at relatively low concentrations in human plasma and urine, and their major forms were identical to authentic big ET-1, ET-1, and ET-3, respectively. Although Et-1 and other ET family peptides have often been measured using RIAs with board-spectrum antibodies, the presence of high concentrations of IR-big ET-2 and IR-big ET-3, but not IR-ET-1, in plasma and urine indicates that the clinical significance of ET family peptides should be investigated with assay methods specific to each ET and big ET.