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Magnetic relaxation of Bi2212 has been measured by use of a micro Hall sensor array. The activation energy (U) of vortex below the second peak increases with decreasing M with an exponent expected from the collective creep theory. On the contrary the U above the second peak seems to saturate with decreasing M. These observations conclude a presence of a definite vortex- matter phase boundary just below the second-peak field. The vortex phase at high field region above this boundary is suggested to be a ‘viscous vortex liquid’.

Local magnetization (M) of overdoped BSCCO-2212, in which the first-order vortex-lattice transition (FOT) has been obscured by the irreversibility behavior, is measured using an array of micro Hall sensors. The spatial profile of M at high temperature side is found to be almost “dome-shaped”, while an effect from the Bean model is observed just below the irreversibility field. The FOT melting-field line at the high temperature side smoothly connects to the line of the second-peak field at the low temperature side, and a relaxing-type irreversibility line starts from the crossover region. Magnetization anomaly at the sample edge is verified to be a good measure of these phase boundaries.

We have studied differences of electrical transports, magnetic properties and crystal structures between superconducting Prl23 single crystals and nonsuperconducting crystals. We synthesized Prl23 polycrystals under low partial pressure of oxygen. These samples show nearly metallic temperature dependence of resistivity. We suggest that in Prl23 crystals, atomic disordering and/or deficiencies influence on electrical transport property and cause insulating behaviour, so the disordering of Pr and Ba is important to suppression of superconductivity in Prl23 compounds.

We describe a family with Liddle's disease caused by a novel mutation of the beta subunit of the human epithelial sodium channel (ENaC). A 15-year-old Japanese female was referred to our outclinic because of hypertension. The physical examination showed no abnormal findings except mild hypertension, but the laboratory data revealed low levels of plasma renin activity, plasma aldosterone and serum potassium. A comprehensive analysis of steroid hormones showed only high levels of urinary free cortisol and 17-hydroxycorticosteroids. During loading tests, blood pressure and serum potassium responded well to triamterene and slightly to spironolactone, but did not respond to dexamethasone. In addition, the normal ratio of tetrahydrocortisol plus 5alpha-tetrahydrocortisol to tetrahydrocortisone in a 24 h urinary excretion test strongly suggested a diagnosis of Liddle's disease rather than apparent mineralocorticoid excess syndrome. DNA sequence analysis of members of this family revealed a single cytosine base insertion at Arg-597 of the beta human ENaC in the proband and her mother, leading to a loss of the last 34 amino acids from the normally encoded protein as the result of a frameshift. We conclude that a de novo cytosine insertion into the final exon of the C-terminus of the beta human ENaC is responsible for Liddle's disease in this Japanese family.

The melting transition of the flux line lattice (FLL) has been investigated in a BSCCO crystal under small transport currents (≤ 10 A/cm2). It is found that while this small transport current does not significantly shift the position of the melting transition, it reduces irreversibility just below the transition. A change in the slope of the local induction is detected prior to the melting transition when the transport current is present. The results could indicate a transition from a ‘weak glass’ to a precursor phase before melting.

In order to investigate the effect of Pr3+ ion in the rare earth (RE) site of PrBa2Cu3O7-δ , we prepared polycrystalline samples of PrBa2-xCaxCu3O7-δ and measured X-ray diffraction, electrical resistivity, and magnetic susceptibility. Differences in physical properties between PrBa2Cu3O7-δ and PrBa2-xCaxCu3O7-δ are reported in this paper.

In vivo microdialysis was used to determine SRIF release from the hypothalamus in unanesthetized male rats over a period of 24 h and in rats deprived of food for 72 h, in relation to changes in plasma GH levels. Before the experiment, a microdialysis probe was inserted into the anterior pituitary gland of the rats with an indwelling right atrial cannula. Dialysates and blood samples were collected serially, after normal feeding or 72-h deprivation of food. Normal rats implanted with the microdialysis probe showed an episodical pattern of GH secretion at intervals of 3 h. SRIF was secreted in a pulsatile fashion in the dark period in a similar manner to the light period. Mean SRIF pulse amplitude and mean SRIF level were significantly increased in the dark period. There was no significant correlation between the SRIF and GH pulses in the light period. SRIF levels in dialysates obtained from fed rats and food-deprived rats showed a pulsatile pattern. Food deprivation resulted in significant increases in mean SRIF level and mean SRIF pulse amplitude. These results suggest that the existence of circadian rhythm in SRIF release and the increase in SRIF release play an important role in suppressing GH secretion during prolonged food deprivation.

For the development of lead-free piezoelectric ceramics, which have a tetragonal–rhombohedral morphotropic phase boundary (MPB), 0.90(Na0.5K0.5)NbO3–xBaZrO3–(0.10 - x)(Bi0.5Li0.5)TiO3 ceramics have been synthesized by the conventional solid state reaction method. A phase diagram was summarized from the X-ray diffraction pattern and the dielectric measurements. It is found that 0.90(Na0.5K0.5)NbO3–xBaZrO3–(0.10 - x)(Bi0.5Li0.5)TiO3 ceramics have an MPB between x = 0.07 and 0.08. In the vicinity of the MPB, it was observed that the dielectric and piezoelectric properties were enhanced.

Magnetic measurements were carried out on Ho2Ru2O7 and Dy2Ru2O7 pyrochlores to study the possibility of spin ice type magnetism in these systems. Curie Weiss law fits to inverse susceptibility data in the temperature range 200– 350 K gave peff=9.60, θ=−4 K for the Ho and peff=10.54, θ=−8.4 K for the Dy system. The saturation magnetization at 2 K was only half the value expected for the ground-state configurations of the rare earth ions. The effective nearest neighbor interaction was estimated to have small positive values for both the systems. This suggests that these pyrochlore systems have a magnetic behavior similar to the other spin ice systems despite the presence of the small moment bearing 4d Ru ions which themselves order into antiferromagnetic state at an elevated temperature of about 100 K .

We report the spin flop transition on LaSrFeO4. A single crystal of LaSrFeO4 has been prepared by the floating-zone method. The Mossbauer spectrum below 370 K consists of a single Fe3+ hyperfine sextet. We observed a magnetization jump around 1.8 T in the magnetization curve below 20 K . From the analysis of the transition field on [1 0 0] and [1 1 0] direction, we found the magnetization jump corresponds to the spin flop transition in the antiferromagnetic ground state of [1 1 0] and [−1 1 0] spin direction in the c plane.

High-density perovskite titanate zirconate-modified potassium niobate solid solutions 0.92(Na0.5K0.5)NbO3–xBaZrO3–(0.08-x)(Bi0.5K0.5)TiO3 (BBK) and Mn-added BBK have been prepared by the solid-state reaction method. The phase diagram summarized from the dielectric measurement reveals that there exists a tetragonal–rhombohedral morphotropic phase boundary (MPB) for both solid solutions. The piezoelectric properties show enhanced behavior at around the tetragonal–rhombohedral MPB. Mn addition could increase Q m as well as k p and d 33. The behavior is attributed to oxygen vacancy formation and grain size growth, respectively.

A 76-year-old man with small cell lung cancer associated with the syndrome of inappropriate secretion of ADH (SIADH) visited our hospital. The serum Na level was normal on the first visit, but 2 weeks later it decreased to 114 mEq/L with an extremely high plasma vasopressin (VP) level of 1520 pg/ml. Serum Na was normalized after the reduction of the tumor size by chemotherapy, but the plasma VP level remained between 150 to 600 pg/ml. On gel filtration of plasma VP two peaks of immunoreactive VP were eluted at the positions of a larger molecule than authentic VP and authentic VP, and VP in urine gave only one peak compared to that of authentic VP. The dilution curve of plasma VP was almost parallel and that of urine was completely parallel to the standard curve. These findings suggest that a larger VP with low physiological activity was predominantly secreted in the present patient and manifested relatively mild symptoms despite the extremely high plasma VP level.

The electronic structure of reduced SrTiO3(110) surface prepared by annealing in ultrahigh vacuum (UHV), has been studied using photoemission spectroscopy (PES) and scanning tunneling microscopy/spectroscopy (STM/STS). In the photoemission spectra of reduced SrTiO3(110) surface after annealing in UHV at 800°C, a clear metallic state with a sharp Fermi cut-off and a broad state centered at ∼1.1eV below the Fermi level are observed in the band gap region. A Ti3p->3d resonance enhancement is occurred for the metallic state, but not for the ∼1.1eV state. On the other hand, after the sample was annealed in UHV at 1000°C, it has been shown that the metallic state becomes drastically weak, and that only the ∼1.1eV state is seen in the band gap region. Thereafter, the ∼1.1eV state exhibits a clear Ti3p->3d resonance enhancement. The difference in the spectral feature of these band gap states is directly related to the surface geometric structural change.

(1-x)(Na0.5K0.5)NbO3–xAZrO3 (A = Sr, Ca) solid solutions have been prepared to study the effcts of A-site ions on the successive phase transition temperatures. It is found that the phase diagram for the solid solutions are very similar: with increasing x, the cubic–tetragonal phase transition temperature T C–T and the tetragonal–orthorhombic phase transition temperature T T–O shift to the lower-temperature region, while the orthorombic–rhombohedral phase transition temperature T O–R shifts to the higher temperature region. When x is between 8 and ∼15 molar percentage, the orthorhombic–rhombohedral phase transition temperature is higher than room temperature and the (1-x)(Na0.5K0.5)NbO3–xAZrO3 solid solutions exhibit rhombohedral symmetry at room temperature. It is found that T C–T is affected by A-site ions; while T T–O and T O–R are almost independent of A-site ions.

Effect of Mn substitution in paramagnetic metal CaRuO3 was studied by magnetization measurements. Development of ferromagnetic order was observed for x ≥ 0.2 in CaRu1-xMnxO3. The ratio of the effective moment and the spontaneous magnetization Peff/M(0) is much larger than one in this ferromagnetic state. At low temperatures the antiferromagnetic order coexists with the ferromagnetic one and the magnetization is significantly suppressed with decreasing temperature. The magnetic phase diagram in CaRu1-xMnxO3 with 0.3 ≤ x ≤ 0.8 estimated from the magnetization measurements is reported.

The clinical significance of parathyroid hormone-related protein in humoral hypercalcemia of malignancy was investigated by determining the serum parathyroid hormone-related protein concentrations in 167 normal subjects, 56 patients with hematologic malignancy and 144 patients with solid tumor. Serum parathyroid hormone-related protein was measured with a radioimmunoassay kit that recognizes the C-terminal portion of the molecule. The serum parathyroid hormone-related protein concentrations were 20.2–50.8 pmol/l (mean±2 sd) in normal subjects, and were elevated in 80% of the patients with malignancies with hypercalcemia, including squamous cell carcinoma and adult T cell leukemia. Moreover, two cases of B cell non-Hodgkin's lymphoma with hypercalcemia had high serum parathyroid hormone-related protein concentrations, which varied in parallel with the tumor size during the clinical course. Of 136 patients with solid tumors with normocalcemia, the serum parathyroid hormone-related protein concentration was slightly elevated in only 5.1%, all of whom were at an advanced stage. These data indicate that determination of the serum parathyroid hormone-related protein concentration is useful for differential diagnosis of humoral hypercalcemia of malignancy and prediction of its development.

The function of the growth hormone-releasing hormone (GHRH)-growth hormone (GH) axis in Cushing's disease was studied by monitoring (a) the GH responses to GHRH loading and L-dopa loading, (b) the GHRH response to L-dopa loading, and (c) the daytime profiles of plasma GH concentration. GH release following GHRH and L-dopa was blunted in patients as compared to that in age-matched control subjects. However, GHRH release following L-dopa was similar in patients and controls. The plasma GH levels in four patients measured every 20 min by a highly sensitive immunoradiometric assay for GH showed pulsatile GH secretion at low levels during the observation period. These results indicate that GHRH release from the hypothalamus is preserved in patients with Cushing's disease, and support the hypothesis that glucocorticoid inhibits GH secretion by altering the hypothalamic somatostatin tone.

Detailed phase diagrams are necessary for improving the temperature stability of piezoelectric properties of (Na,K)NbO3-based solid solutions. We report the phase diagrams of the (1−x)Na0.5K0.5NbO3–xMTiO3 (M=Pb, Ba, Sr, Ca, and Bi0.5Li0.5) solid solutions over a broad temperature range of 10 K≤T≤∼770 K. It is found that the phase diagrams show several universal characteristics: (a) Curie temperature TC-T decreases sharply at low x range; (b) the relation between TC-T and x deviates from Vegard’s law; and (c) the tetragonal-orthorhombic phase transition temperature TT-O and the orthorhombic-rhombohedral phase transition temperature TO-R are almost independent of M. We suggest that valence mismatch is the main reason for the rapid decrease in TC-T and the deviation of TC-T from Vegard’s law. It is also found that TC-T is mainly affected by the A-site cations, whereas TT-O and TO-R are mainly affected by the B-site cations.

The possibility that a pairing boson might act as the 'glue' to bind electrons into a Cooper pair in superconductors with a high critical temperature (T(c)) is being actively pursued in condensed-matter physics. Gweon et al. claim that there is a large and unusual oxygen-isotope effect on the electronic structure, indicating that phonons have a special importance in high-temperature superconductors. However, we are unable to detect this unusual oxygen-isotope effect in new data collected under almost identical material and experimental conditions. Our findings point towards a more conventional influence of phonons in these materials.

Effect of doping electrons on the electronic structure of single-crystalline LaxSr1−xTiO3 samplex (x=0.001, 0.01, 0.05) has been studied for the fractured surface by ultraviolet photoemission spectroscopy (UPS). Two peaks in the band gap region of SrTiO3 (in-gap peaks) are induced by La substitution for Sr; a peak with a sharp Fermi cut-off (metallic peak) and a broad peak centered at ∼1.5 eV below EF(∼1.5 eV peak). The spectral intensity of the metallic peak and the ∼1.5 eV peak increases with the carrier concentration, but the spectral width of the metallic peak does not depend upon it. The behaviors of doping electrons on the electronic structure near EF of LaxSr1−xTiO3, such as no change in the spectral width of the metallic peak and the appearance of the ∼1.5 eV peak, can not be simply explained by the band theory.

We present detailed energy dispersions near the Fermi level along the high symmetry line GammaX on the monolayer and bilayer strontium ruthenates Sr2RuO4 and Sr3Ru2O7, determined by high-resolution angle-resolved photoemission spectroscopy. A kink in the dispersion is clearly shown for the both ruthenates. The energy position of the kink and the slope in the low-energy part near the Fermi level are almost identical between them, whereas the dispersion in the high-energy part varies, like the behavior of the kink for the cuprate superconductors.

The electronic structure of reduced SrTiO3(110) surface prepared by annealing in ultrahigh vacuum (UHV), has been studied using photoemission spectroscopy (PES) and scanning tunneling microscopy/spectroscopy (STM/STS). In the PES spectra of reduced SrTiO3(110) surface after annealing in UHV at 800°C, a clear metallic state with a sharp Fermi cut-off and a broad state centered at ∼1.1eV below the Fermi level are observed in the band gap region. A Ti3p->3d resonance enhancement is occurred for the metallic state, but not for the ∼1.1eV state. On the other hand, after the sample was annealed in UHV at 1000°C, it has been shown that the metallic state becomes drastically weak, and that only the ∼1.1eV state is seen in the band gap region. Thereafter, the ∼1.1eV state exhibits a clear Ti3p->3d resonance enhancement. The difference in the spectral feature of these band gap states is directly related to the surface geometric structural change.

We investigated a method for obtaining a sintered bulk sample of single-phase Sr2MoO4, which has recently increased in importance due to its similarities to superconducting Sr2RuO4. We discovered that with the aid of Ti2O3 as a p(O2) buffer, high-purity Sr2MoO4 is successfully synthesized in a sealed tube. We confirmed the space group and determined the exact elemental composition of the compound in order to establish its stoichiometry. The guideline for the rational choice of a p(O2)-buffer material is discussed., Comment: 4 pages, 4 figures

We studied phonon-assisted tunneling and the peak-to-valley ratio ( P/V ratio) of magnetically confined “dot-like” electron systems in an InGaAs/InAlAs triple barrier resonant tunneling diode. We observe phonon bottleneck, i.e., suppression of the nonresonant valley current and two mode narrow band GaAs- and AlAs-like longitudinal optical (LO)-phonon-assisted tunneling peaks. The P/V ratio increases remarkably with the magnetic confinement and has a maximum each time the energy separation of the confined states matches the GaAs-LO-phonon energy.

Microscopic structure and electronic states on the BaTiO3(100) single-crystal surfaces annealed in ultrahigh vacuum were observed by scanning tunneling microscopy and spectroscopy (STM/S). The surface step edges aligned preferentially along the [001] family of axes as the annealing temperature was increased. After annealing at temperatures above 800° C, spatial ordering of Ti 3d-oxygen vacancy complexes appeared on the surface. The STS spectra showed in-gap electronic states at about 1.0 eV below Fermi energy, which agreed well with the results of ultraviolet photoelectron spectroscopy previously reported.

Structure and electronic states on the (100) surface of reduced BaTiO3 single crystals were observed by scanning tunneling microscopy and spectroscopy. After annealing at 1150 °C, the direction of the edges ordered to run along the equivalents of [011] and [001] directions. All the observed step edges were of unit‐cell height. On each terrace atomlike corrugation with the periodicity multiples of the √5×√5 R26.6° superlattice was observed in the filled state images. A straightforward method to deduce the local density of states from the scanning tunneling spectroscopy data was introduced, based on multiplication of an inverted triangular transfer matrix, and was applied to the scanning tunneling spectroscopy data on the terraces. The amplitude of the local density of states at EF−1 eV varied in phase with the atomlike corrugation on the terrace, which was consequently ascribed to electronic states at the spatially ordered Ti 3d–oxygen vacancy complexes on the surface.

The scanning tunneling microscope (STM) was invented less than five years ago by G. Binnig and H. Rohrer. In 1986 they were honored with the Nobel prize in physics, together with E. Ruska who invented the transmission electron microscope in 1933. The principles of the STM and the construction of the instruments are described by dividing them into several key technologies: (i) vibration isolation; (ii) course and fine positionings and scannings; (iii) thermal drift, hysteresis, and creep of piezoactuaters; (iv) metal probes; and (v) electronic control circuits. Surface structures recently observed by the STM on metals, semiconductors, etc. are reviewed. The future development of the STM is mentioned very briefly.

The ambient-pressure superconductivity in β-(BEDT-TTF) 2 I 3 and its mixed trihalide homologues has been studied, where BEDT-TTF is bis-(ethylenedithio-tetrathiafulvalene. In β-(BEDT-TTF) 2 I 3 , two superconductivity states are observed, i.e. , a low- T c state with T c = 1.1 – 1.5 K and a high- T c state with T c = 7 – 8 K. The high- T c state, which was originally discovered under a pressure of 1.3 kbar, is found to remain stable after removal of pressure. Moreover it has also been observed even without application of pressure. In order to realize an intrinsic high- T c ambient-pressure organic superconductor, we propose an introduction of ‘lattice pressure’ by substitution of triiodide anion (I 3 − ) with smaller mixed trihalide anions, such as I 2 Br − and IBr 2 − . The result is discussed using a model based on the T c vs. pressure phase diagram for β-(BEDT-TTF) 2 I 3 .

Low temperature phase diagram of β-(BEDT-TTF) 2 I 3 as a function of pressure ( P ) is determined by resistivity measurement. The superconducting transition temperature ( T c ) rises from 1.1–1.5 K ( P =0 kbar) to around 7.4 K ( P =1.3 kbar) and decreases to 1.2 K ( P =7 kbar). We propose that two kinds of superconducting states exist in this salt and that ambient pressure gives two stable states which have T c 's of around 8 K as well as around 1.3 K. The upper critical field, H c2 , along the c * -axis is also presented.

The transverse magnetoresistance along the a axis exhibits anomalous angular dependence with respect to the direction of a magnetic field. The behavior varies with the temperature and the field intensity.

The high T c superconducting state of β -(BEDT-TTF) 2 I 3 was investigated through the measurement of the upper critical field, H c2 . In relation to the anisotropy of the superconductivity and the pressure dependence of superconducting transition temperature, the anisotropy of the normal state conductivity was studied as a function of pressure and temperature. We show that the ratio of conductivity, and then the ratio of the transfer energy between a- and c ∗ - axes changes little in a wide range of temperature and pressure. The ratio of H c2 near T c is explained by that of the conductivity.

The transverse magnetoresistances along both the a (σaa) and the b (σbb) directions are compared with the calculated based on the tight binding band model. The magnetic field dependence of σbb can be well explained with the model, whereas Paa cannot be. This suggests that some mechanism other than the single particle transport is dominating. Possibilities of the contribution from the fluctuating superconductivity, the magnetic breakthrough, and the SDW are discussed.

Hypothalamic-pituitary function was evaluated in a combination of tests with four hypothalamic releasing hormones (4RHs) and L-dopa in normal subjects and in patients with hypothalamic and/or pituitary disorders. Plasma concentrations of anterior pituitary hormones (GH, ACTH, TSH, PRL, LH and FSH) were measured before and after simultaneous iv administration of GHRH, CRH, TRH and LHRH. In addition, changes in the plasma levels of GHRH and GH were investigated before and after oral administration of L-dopa. Normal subjects showed appreciable responses to both tests. In five patients with hypothalamic disorders, the response of plasma anterior pituitary hormones varied, but plasma GHRH and GH did not respond to L-dopa. Patients with idiopathic and postpartum hypopituitarism showed low response to 4RHs or none at all, but L-dopa evoked a normal GHRH response in 2 of the 4 cases having no GH response. In the patients with hypopituitarism due to resection of a pituitary tumor, the response of anterior pituitary hormones to 4RHs was low, and L-dopa administration induced a normal GHRH and low GH response in 5 out of the 7 cases. After 4RHs administration, the patients with ACTH deficiency syndrome showed different patterns of impaired ACTH secretion, and isolated, combined or limited ACTH reserve. Seven patients with anorexia nervosa showed exaggerated GH, delayed TSH and FSH, low ACTH and LH, that is, normal PRL response to 4RHs, but no response of plasma GHRH or GH to L-dopa, suggesting the presence of hypothalamic dysfunction. These results indicate that the combination of the 4RHs test and L-dopa test is a simple and useful means for evaluating hypothalamic-pituitary function by measuring the response of plasma GHRH and six anterior pituitary hormones in the patients with endocrine disorders.

HCG産生鞍上部胚芽腫により,尿崩症,高Na血症,視床下部性下垂体前葉機能低下症,高プロラクチン血症などの視床下部症候群を呈し,経過中に急性腎不全を合併した14才男性例を報告した. TRH・LHRH・LVP・GHRHによる4者負試験およびinsulin, arginine, L-dopaの各負荷試験を用いて,放射線照射と化学療法による治療前後の視床下部下垂体機能の変化を明らかにした.急性糸球体腎炎に起因すると思われる急性腎不全期には,尿量の減少,クレアチニンクリアランスの低下およびNa血症の改善を認めた.尿崩症に腎不全が合併した症例は未だ報告がなく,尿崩症の場合の尿量も糸球体〓過率によって強く影響をうけることが示された.

The thrombolytic mechanism of pro-urokinase (Pro-UK) was investigated. Pro-UK is of a single-chain form, and is converted to UK with plasmin-Sepharose. The [3H]DFP incorporation was strongly enhanced by plasmin treatment, which induces conformational changes as observed from the circular dichroism. A relatively higher affinity of Pro-UK for fibrin than that of UK was found by adsorption on fibrin-Sepharose and also by incorporation into fibrin during fibrinogen-fibrin conversion. Pro-UK produced effective thrombolysis without degrading fibrinogen. The presence of t-PA in the thrombus promoted thrombolysis effectively. Further, coexistence of t-PA and Pro-UK in the plasma markedly enhanced the thrombolysis. The adsorption of Pro-UK, plasminogen and t-PA on fibrin-Sepharose induced rapid activation of Pro-UK to UK as well as rapid production of plasmin on the fibrin surface. These results suggest that a trace amount of t-PA causes marked enhancement of Pro-UK induced thrombolysis.

A review is given on applications of scanning tunneling microscopy to the study of various superconductor surfaces. Measurements on surfaces of Nb3Sn films, NbN films, and oxide superconductors are described following a brief introduction to the characteristics of scanning tunneling microscopy and spectroscopy.

We have fabricated (TMTSF)2ClO4/a-Si/Pb junctions using CVD a-Si film as low-potential tunnel barriers. From measurements well below TC, 3D superconducting transition temperature of (TMTSF)2ClO4, the superconducting energy gap comparable to the BCS theory was detected. At higher temperatures no significant change other than the superconducting transition of Pb was observed. In the quenched crystals much larger gap structure 2Δ≃ 3 meV was observed, resulting from the SDW state.

Transverse magnetoconductivity tensor components have been measured in dilute Bi:Sn and Bi:Te alloys up to magnetic field/temperature = 13T / 0.5 K and compared with those of high purity sample. As was expected, perfect phase inversion and enhancement of the quantum oscillation of the magnetoresistivity component were observed. It was also found that peaks of Hall resistivity tensor component due to the hole Fermi surface in the highest magnetic field region revealed dispersion-type line shape in Bi:Sn alloy in contrast to those in Bi:Te alloy or in pure Bi, which may be ascribed to the difference between the screening of anions and that of cations by electrons and holes in these semimetals.

Oscillations in the transverse magnetoresistance of β-(BEDT-TTF) 2 I 3 and β-(BEDT-TTF) 2 IBr 2 were observed below 4.2 K in fields above 9 Tesla applied perpendicular to the a – b plane. The period of the resistance oscillation vs the inverse magnetic field proved that the cross-sectional area of the two-dimensional Fermi surface was nearly a quarter of the first Brillouin zone for both β-(BEDT-TTF) 2 I 3 and β-(BEDT-TTF) 2 IBr 2 . Beat-like phenomenon in the magnetoresistance oscillation was also observed in both salts, and its origin is discussed. The fact that the two salts are quite similar in Shubnikov-de Haas effect suggests that the difference in the band structure in the low- and high- T c states of β-(BEDT-TTF) 2 I 3 is small.

SUMMARY Investigations of charge-density waves (CDW) in 4Hb-TaS2 and the shifted Fermi level in a CoCl2 graphite intercalation compound (GIC) were performed by scanning tunnelling microscopy (STM) and scanning tunnelling spectroscopy (STS) A discrimination of the surface electronic structure of the octahedral structure and of the trigonal-prismatic structure in 4Hb-TaS2 was made successfully in terms of the electronic properties. The measured value of the charge-density-wave gap in 4Hb-TaS2 at room temperature was about 85 meV. The shifted Fermi level in CoCl2-GIC was measured to be about 400 meV.

High-performance affinity chromatography was performed on five ligand-bound columns in an attempt to purify tissue-type plasminogen activator (t-PA), which is a glycoprotein with a high affinity for fibrin and also has two Kringle structures and finger-domain in its molecule. The five columns were concanavalin A-5PW, p-aminobenzamidine-5PW, imidinodiacetic acid-5PW, boric acid-5PW and lysine-5PW. All five were able to rapidly separate t-PA from contaminating proteins, with high resolution and recovery.