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In the early 1990s, Yamazaki et al. developed a partly intra-ventricular pump, which was inserted into the left ventricle via the apex and then into the aorta through the aortic valve. The pump delivered blood flow directly from the left ventricle to the aorta, like a natural heart, and needed no inflow and outflow connecting tubes; it could be weaned off after the left ventricle had been recovered. The shortcomings were that the driving DC motor remained outside of the ventricle, causing an anatomic space problem, and the sealing and bearing were not appropriate for a durable device. Recently, a totally implantable trans-ventricular pump has been developed in the authors' laboratory. The device has a motor and a pump entirely contained within one cannula. The motor has a motor coil with iron core and a rotor with four-pole magnet; the pump has an impeller and an outflow guide vane. The motor part is 60 mm in length and 13 mm in diameter; the pump part is 55 mm in length and 11 mm in diameter. The total length of the device is therefore 115 mm. The total weight of the device is 53 g. The motor uses rolling bearing with eight needles on each side of the rotor magnets. A special purge system is devised for the infusion of saline mixed with heparin through bearing to the pump inlet (30 - 50 cc per hour). Thus neither mechanical wear nor thrombus formation along the bearing will occur. In haemodynamic testing, the pump can produce a flow of 4 l min-1 with 60 mmHg pressure increase, at a pump rotating speed of 12,500 rpm. At zero flow rate, corresponding to the diastolic period of the heart, the pump can maintain aortic blood pressure over 80 mmHg at the same rotating speed. This novel pump can be quickly inserted in an emergency and easily removed after recovery of natural heart. It will be useful for patients with acute left ventricular failure.

Orbital magnetism in an integrable model of a multichannel ring with long-ranged electron-electron interactions is investigated. In a noninteracting multichannel system, the response to an external magnetic flux is the sum of many diamagnetic and paramagnetic contributions, but we find that for sufficiently strong correlations, the contributions of all channels add constructively, leading to a parity (diamagnetic or paramagnetic) which depends only on the total number of electrons. Numerical results confirm that this parity-locking effect is robust with respect to subband mixing due to disorder., Comment: part of lecture presented in the conference ``Unconventional quantum liquids", appearing in Z. Phys

In this work, we have studied the invariants of motion of two SU(N) supersymmetric t-J models of 1/r 2 hopping and exchange in one dimension. The first model is defined on a lattice of equal spaced sites, and the second on a nonequal spacing lattice. Using the “exchange operator formalism”, we are able to construct all the invariants for the models, by mapping the systems to mixtures of fermions and bosons. This identification shows that the supersymmetric t-J model on the chain with equal-spaced sites also belongs to Shastry-Sutherland’s “super-lax-pair” family.

In this work, I generalize Merton's approach of pricing risky debt to the case where the interest rate risk is modeled by the CIR term structure. Closed form result for pricing the debt is given for the case where the firm value has non-zero correlation with the interest rate. This extends previous closed form pricing formular of zero-correlation case to the generic one of non-zero correlation between the firm value and the interest rate., 7 pages, Revtex style

Abstract This paper describes, for the first time, a unique investigation of ASR using synthetic sandstone samples formed under applied polyaxial stresses. The strain relaxation in all tests invariably gave a good indication of the principal stress orientations. Measured strain relaxation ratios were approximately equal to corresponding applied stress ratios up 1.5, suggesting that, with a knowledge of one of the principal stresses, in regions of low stress anisotropy, stress can be calculated directly from strain. At stress ratios of 2 and above, corresponding relaxation strain ratios were variable, time- dependent and generally higher than the stress ratios. This suggests that shear stresses associated with stress anisotropy result in material damage that is partly responsible for the measured relaxation strain. Correction of strains for "Poisson" effects reduced data scatter at the higher stress anisotropies but gave a poor correlation between applied stress and a) strain magnitudes, b) calculated stress, for a measured Poisson ratio (v) of 0.3. Lower v values gave better data fit, but it is suggested that the use of a Poisson correction of (he measured strain. Using low values of v, is unrealistic. The strain relaxation mode was assessed using the Kelvin-Voight model. The strain relaxation curves are not perfectly linear in normalised strain/time space. The material behaviour cannot therefore be fully reproduced using this visco-elastic model. Anisotropic samples especially seem to deviate from a linear trend, again suggesting that stress anisotropy and related fabric damage have an effect on the ASR response. P. 161

In this letter, I consider the issue of pricing risky debt by following Merton's approach. I generalize Merton's results to the case where the interest rate is modeled by the CIR term structure. Exact closed forms are provided for the risky debt's price., Comment: Revtex, 8 pages

The persistent current $I$ in integrable models of multichannel rings with both short- and long-ranged interactions is investigated. $I$ is found to oscillate in sign and increase in magnitude with increasing interaction strength due to interaction-induced correlations in the currents contributed by different channels. For sufficiently strong interactions, the contributions of all channels are found to add constructively, leading to a giant enhancement of $I$. Numerical results confirm that this parity-locking effect is robust with respect to subband mixing due to disorder., Latex, prerpint of Univ. Fribourg and Ecole Fed. Polytech, submitted to PRL for publication

The integrability of the one-dimensional long range supersymmetric t-J model has previously been established for both open systems and those closed by periodic boundary conditions through explicit construction of its integrals of motion. Recently the system has been extended to include the effect of magnetic flux, which gives rise to a closed chain with twisted boundary conditions. While the t-J model with twisted boundary conditions has been solved for the ground state and full energy spectrum, proof of its integrability has so far been lacking. In this letter we extend the proof of integrability of the long range supersymmetric t-J model and its SU(m|n) generalization to include the case of twisted boundary conditions., preprint of Rockefeller-ETH, submitted to PRB rapid communication

In this work, we study a continuous quantum system of a mixture of bosons and fermions with the supersymmetry SU(m|n). The particles are confined in a harmonic well and interact with each other through the 1/r2 interaction. The ground state wavefunction is constructed explicitly for the most general SU(m|n) case, with the ground state energy given explicitly. The full energy spectrum of excitations in the SU(m|n) model is also equal spaced. In the limiting case where there are no bosons in the system, our results reduce to those obtained previously., 9 pages, preprint of ETH-Lausanne (August 1996)

We examine the ground state and excitations of the one-dimensional supersymmetric extended Hubbard model with long-range interaction. The ground state wave-function and low lying excitations are given explicitly in the form of a Jastrow product of two-body terms. This result motivates an asymptotic Bethe ansatz solution for the model. We present evidence that this solution is in fact exact and spans the complete spectrum of states. {copyright} {ital 1996 The American Physical Society.}

Epidermal growth factor (EGF) receptor was detected in the human Chang liver and human hepatoma HepG2 cells. Both cell lines were found to be able to bind EGF. The expression of EGF receptor in Chang liver and HepG2 cells was 1.3 x 10(5) EGF receptors/cell and 1.8 x 10(5) EGF receptors/cell, respectively. In both cells, this receptor was identified by ECL Western blotting using monoclonal anti-EGF receptor antibody and by immunohistochemical assay using polyclonal anti-EGF receptor antibody. Some of internalized EGF was recycled in Chang liver cells, but not in HepG2 cells.

In this work, we introduce long range version of the extended Hubbard model. The system is defined on a non-uniform lattice. We show that the system is integrable. The ground state, the ground state energies, the energy spectrum are also found for the system. Another long range version of the extended Hubbard model is also introduced on a uniform lattice, and this system is proven to be integrable., 10 pages, Latex. Typoes are fixed in this revised version

The Hofstadter problem is studied on hexagonal lattice. We first establish a relation between the spectra for the hexagonal lattice and for its dual he triangular lattice. Following the idea of Faddeev and Kashaev, we then obtain the Bethe-ansatz equations for this system., 8 pages, latex, revised version for Phys. Lett. A

In this work, the stability of the insulating phase of the 1D chiral Kondo lattice model is studied at half-filling, within the framework of self-consistent variational theory. It is found that arbitrarily small interaction would drive the system from a conducting phase to an insulating phase, in spite of the chirality of the conducting band., 10 pages, IPT-EPFL preprint, submitted to PRB as a brief report for publication

Photoenhanced electrochemical (PEC) etching in an unstirred KOH solution under He–Cd laser illumination was used for delineating extended defects in GaN films. When a low-excitation intensity was employed, the process yielded threading vertical features at dislocation sites. Application of an external voltage or a higher-illumination intensity led to high-etch rates with smooth surfaces. Some highly resistive samples, for which no etching was obtained under normal etching conditions, could be etched with the application of a single-polarity external voltage. Finally, in a GaN sample with an AlN/GaN superstructure inside, high selectivity between AlN and GaN was achieved; in this case, the PEC process stopped at the thin AlN stop layer.

In this work, we exactly solve a Kondo lattice model in the thermodynamic limit. The system consists of an electronic conduction band described by unconstrained hopping matrix elements between the lattice sites. The conducting electrons interact with a localized impurity spin at each lattice cell. We have found the exact thermodynamics, the ground state energies of the system. At T=0, we explicitly demonstrate that the system exhibits a metal-insulator phase transition at half-filling. In the limit of strong coupling between the impurity spin and the electrons, J=\infty, we have solved the system on a lattice of any size L. The ground states are the resonating-valence-bond type Jastrow product wavefunctions. Various correlation functions may be computed for the impurity spins, and for the singlets formed by the electrons and impurities., Comment: Revtex, 15 pages, minor errors fixed, wavefunctions added Final version on PRB (1995)

In this work we introduce one dimensional multi-component Hubbard model of 1/r hopping and U on-site energy. The wavefunctions, the spectrum and the thermodynamics are studied for this model in the strong interaction limit $U=\infty$. In this limit, the system is a special example of $SU(N)$ Luttinger liquids, exhibiting spin-charge separation in the full Hilbert space. Speculations on the physical properties of the model at finite on-site energy are also discussed., 9 pages, revtex, Princeton-May12

In this work, we study the wave functions of the one-dimensional 1/r Hubbard model in the strong-interaction limit U = ∞. A set of Gutzwiller-Jastorw wave functions are shown to be eigenfunctions of the Hamiltonian. The entire excitation spectrum and the thermodynamics are also studied in terms of more generalized Jastrow wave functions. For the wave functions and integrability conditions at finite on-site energy, further investigations are needed.

Velvetleaf (Abutilon theophrasti Medic), a tall, fecund, self-fertile annual plant in the family Malvaceae, is widely grown in China as a fiber crop and for its medicinal properties. In July of 2008, we observed diffuse chlorotic and necrotic spots on the oldest leaves of velvetleaf plants in the field in Shanxi Province. Sap extracts from six symptomatic plants were tested by direct antigen coated ELISA using polyclonal antibodies specific to Potato virus Y (PVY) and monoclonal antibodies specific to Tomato mosaic virus (ToMV), Cucumber mosaic virus (CMV), and Tobacco mosaic virus (TMV). Five of the six samples were negative for ToMV, CMV, and PVY but positive for TMV. Double-stranded RNA extracted from leaves of the five velvetleaf plants was used as template for reverse transcription (RT)-PCR as described by Krajačića et al. (1) and Li et al. (2) with some modifications. One-step RT-PCR was performed using a Quant One Step RT-PCR Kit (TIANGEN BIOTECH CO., LTD., Beijing, China) with sense (5′-CTGTTTAGCCGGTTTGGT-3′), and antisense (5′-TCCCTTTACGGACATCAC-3′) primers (3) designed to specifically amplify a fragment of the movement protein coding region of TMV. The expected 470-bp fragments were amplified from dsRNA from these five plants and the amplicon from each plant was cloned and sequenced (GenBank Accession No. FJ873800). Comparisons of a consensus sequence derived from the five amplicons with the nucleotide sequences available in the NCBI database using BLAST showed 99% identity with TMV from South Korea (GenBank Accession No. AB354955) and Spain (Accession No. AJ308692) and 98% with TMV from China (Accession No. AF165190). The serological, RT-PCR results and sequence data revealed that these velvetleaf plants were infected by TMV. On the basis of the serological analysis and genome sequence comparisons, this isolate was tentatively designated as TMV-Velvetleaf. To our knowledge, this is the first report of TMV in Abutilon theophrasti Medic in China. References: (1) M. Krajačić et al. J. Chromatogr A. 1144:111, 2007. (2) H. Li et al. Agric. Sci. Chin. 6:86, 2007. (3) Y. B. Niu et al. Chin. Biotechnol. 29:76, 2009.

During a period of 36 years, the rate of hysterectomy was 0.054% of all obstetric patients in our hospital, 0.0446% of cesarean section cases, and 0.005% of vaginal deliveries respectively. From 50 s to 80 s, the cesarean section rate greatly increased while the hysterectomy rate in parturition decreased. The indications for cesarean hysterectomy change from ruptured uterus, abruptio placenta and intrapartum infection to uterine atony highly increased placenta or myoma of the uterus. Cesarean hysterectomy rate due to splitting of uterine wound after cesarean section highly increased in 80 s. Bleeding for more than 1,000 ml during operation accounted for 62.7% of them. However, operative complication rate reached to 11.8%. To reduce cesarean hysterectomy rate, we suggest emphasizing maternal health care, use of uterine packing to lessen bleeding and careful management of operation as important means for reducing uterine incision wound splitting after cesarean section.

Zn0.96Mn0.04O∕ZnO coaxial nanocable and Zn0.96Mn0.04O film were prepared by two-step method and magnetron sputtering, respectively. The x-ray diffraction analysis reveals that Mn is incorporated well into the wurtzite ZnO without formation of Mn or Mn oxide. The high resolution transmission electron microscopy image and the selected-area electron diffraction pattern demonstrate that both ZnO and Zn0.96Mn0.04O layers are single crystalline and an epitaxial growth is achieved between Zn0.96Mn0.04O and ZnO in the coaxial nanocable. The magnetic property measurements show that both Zn0.96Mn0.04O∕ZnO nanocable and Zn0.96Mn0.04O film are ferromagnetic at room temperature. Moreover, the saturated magnetization and the coercive field of Zn0.96Mn0.04O∕ZnO coaxial nanocable are larger than those of Zn0.96Mn0.04O film.

The primary structures and the disulfide-bond pairings of two chromatographic forms A and B of a venom protein from white-faced hornet (Dolichovespula maculata) were determined. This protein, designated as antigen 5 (Dol m V), has 204-205 amino acid residues and it contains 4 disulfide bonds. This protein is an allergen in man but its biologic function in hornet is not yet known. Dol m V is found to have partial sequence similarity with pathogenesis-related proteins from tobacco and tomato leaves and with a sperm-coating protein from rat epididymis.

This paper describes an experimental study of the anelastic strain relaxation (ASR) behaviour of a synthetic sandstone aimed at assessing the use of core-based techniques for stress measurement. The “sandstone” was compacted and “cemented” under stress, unloaded and placed in an ASR cell to monitor its strain response. The relationships between the axial and radial strains and applied stresses were studied for a number of stress fields including isotropic (7 to 28 MPa), anisotropic (7, 14 MPa) and complex (7, 14 MPa, reversed to 14, 7 MPa). The ASR response of the material was generally consistent with theory, showing greater relaxation in the direction of the larger stress, and isotropic relaxation after isotropic loading. The behaviour became more consistent at loads exceeding 10 MPa, applied for durations exceeding 12 hours. The ratio of relaxation strain to applied stress was remarkably consistent in the radial and axial directions for isotropic and anisotropic loading cases. However, the relaxation strain decreased with increasing stress, showing a non-linear “stress-strain” response. The preliminary results from the complex stress field experiments show a “memory” of both applied stress fields, which seems to be controlled by duration of loading. These findings promise to give us greater confidence in the use of the ASR stress measurement technique on sandstones.

The 200‐MeV electron linac at the Hefei National Synchrotron Radiation Laboratory (HESYRL) is described. It is not only an injector of the 800‐MeV storage ring, but an electron accelerator used for nuclear physics experiments and some other applications as well. The main design parameters and measuring results of the LINAC are given. The linac is a travelling wave structure, operating at a frequency of 2856 MHz, constant impedance, in a 2/3π mode. Its total length is about 35 m. Five klystrons are used as rf power; each klystron will provide 15 MW. In November 1987, the machine was successfully commissioned and typical operating parameters are 220 MeV, and 50 mA with an energy spread of ±0.8%.

The use of a laser-Doppler anemometer to measure velocities in a fluid with a larger variation in its refractive index perpendicular to the laser beams may introduce appreciable errors. This situation is commonly encountered in convective heat transfer studies. The beams are refracted as they pass through the fluid and the distance of the intersection of the beams, control volume, from the surface may be significantly different than the distance of the beams from the surface when they entered the fluid. If the flow is unsteady or turbulent, the relative movement of the beams may be such that the size and location of the control volume is constantly changing causing appreciable errors.

Photoenhanced electro-chemical (PEC) wet etching has been shown to be suitable for dislocation-density estimation in n-GaN films as well as for GaN-based device fabrication. We report on PEC etching of n-GaN samples grown by MBE and HVPE methods in unstirred aqueous KOH solution under He-Cd laser illumination. Characterization of the etched samples was carried out using atomic force microscopy (AFM) in both cross-sectional and plan-view configurations and scanning electron microscopy (SEM). At moderate illumination densities, the SEM and AFM analyses reveal sub-100 nm scale threading vertical wires on the etched surfaces. The calculated density (∼1×10 9cm−2) is in agreement with dislocation density found by transmission electron microscopy. Using cross-sectional AFM, we find that these vertical wires are ∼1[.proportional]m high and are perpendicular to the sapphire surface. Applying a higher illumination density or an external voltage, we obtain a higher etch rate with a smooth free-feature etched surface. Some highly resistive samples that cannot be etched under normal conditions because the band bending is too small to confine the holes to the surface for them to participate in the PEC process, can be etched with the application of a voltage to the sample. In this case, the etch rate depends on both the polarity and the magnitude of the voltage applied. In an MBE-grown sample with an AlN/GaN superstructure inside, we report on high selectivity between AlN and GaN (AlN is an etch stop); the selectivity is due to the etching mechanism of the PEC process.

Ultrastructure of cellular inclusions in the cerebral cortex and in renal tubule epithelial cells in a case of late infantile metachromatic leukodystrophy were investigated. Four patterns of shape were illustrated as multi-lamellated structure, zebra bodies, dense bodies and vacuoles with the two latter being more predominant in the renal tubule cells. Histochemical studies of the cellular deposits with toluidine blue and cresyl violet all revealed metachromatic in character. Significance of these findings and their pathogenesis were discussed.

The ethanolic extract of the flower of Althaea rosea inhibits significantly the acetic acid-induced twisting of mice and the heat induced (tail) flicking of rats, the acetic acid-induced increase in permeability of abdominal bloud capillaries, the edema of the rat paw induced by carrageenin or dextran, and the release of PGE from inflammatory tissue.

Wire routing is the problem of determining the physical locations of all the wires interconnecting the circuit components on a chip. Since the wires cannot intersect with each other, they are competing for limited spaces, thus making routing a difficult combinatorial optimization problem. We present a new approach to wire routing that uses action languages and satisfiability planning. Its idea is to think of each path as the trajectory of a robot, and to understand a routing problem as the problem of planning the actions of several robots whose paths are required to be disjoint. The new method differs from the algorithms implemented in the existing routing systems in that it always correctly determines whether a given problem is solvable, and it produces a solution whenever one exists.

The structural quality of the buffer layer juxtaposed to the substrate is pivotal in attaining high quality GaN layers. In MBE deposition, low temperature, medium temperature and high temperature AlN buffer layers are at the disposal of the grower. There are quite a few reports, some discussing the benefits of high temperature buffer layers and others doing the same for low temperature buffer layers. The reports emanate from different laboratories; and due to stringent parameter control required, it is difficult to compare one type of buffer with another. To gain some insight, we undertook an investigation wherein these varieties of buffer layers were grown on nitridated sapphire substrate under similar conditions for a comparative analysis. In addition to the single buffer layers of both GaN and AlN varieties, some combinations of stacked buffer layers, including cases where these buffer layers were separated by GaN layers, were employed. Structural analysis by high resolution X-ray diffractometry and topological analysis by AFM were carried out to assess the quality of the epilayers grown on these buffers. Hall measurements at room temperature were carried out to characterize the electrical transport properties.