IL-28B (IFN-λ3) and IFN-α synergistically inhibit HCV replication

Genetic variation in the IL-28B (interleukin-28B; interferon lambda 3) region has been associated with sustained virological response (SVR) rates in patients with chronic hepatitis C treated with peginterferon-α and ribavirin. However, the mechanisms by which polymorphisms in the IL-28B gene region affect host antiviral responses are not well understood. Using the HCV 1b and 2a replicon system, we compared the effects of IFN-λs and IFN-α on HCV RNA replication. The anti-HCV effect of IFN-λ3 and IFN-α in combination was also assessed. Changes in gene expression induced by IFN-λ3 and IFN-α were compared using cDNA microarray analysis. IFN-λs at concentrations of 1 ng/mL or more exhibited concentration- and time-dependent HCV inhibition. In combination, IFN-λ3 and IFN-α had a synergistic anti-HCV effect; however, no synergistic enhancement was observed for interferon-stimulated response element (ISRE) activity or upregulation of interferon-stimulated genes (ISGs). With respect to the time course of ISG upregulation, the peak of IFN-λ3-induced gene expression occurred later and lasted longer than that induced by IFN-α. In addition, although the genes upregulated by IFN-α and IFN-λ3 were similar to microarray analysis, interferon-stimulated gene expression appeared early and was prolonged by combined administration of these two IFNs. In conclusion, IFN-α and IFN-λ3 in combination showed synergistic anti-HCV activity in vitro. Differences in time-dependent upregulation of these genes might contribute to the synergistic antiviral activity.

Contrast media injection into right coronary artery caused thrombus extraction to aorta that may have resulted in left main trunk thrombosis

A 59-year-old man with inferior acute myocardial infarction underwent an urgent coronary angiography and as a result a total occlusion of the ostial right coronary artery (RCA) was observed. Interestingly, the thrombus in the RCA clearly shortened within 2.3 s during the contrast media injection. While we prepared for percutaneous coronary intervention (PCI) of the RCA, ventricular fibrillation occurred and pulseless electrical activity continued in spite of repeated cardioversion. Despite no stenosis in the left main trunk (LMT) in the initial coronary angiography, the LMT was totally occluded. Following aspiration therapy on the LMT with percutaneous cardiopulmonary support, PCI of the RCA was performed. A coronary angiography should be carefully performed if a lot of thrombi exist in the coronary ostium because LMT embolism may have been caused by thrombus extraction from the RCA by contrast media injection.

Quantum dynamics of a driven correlated system coupled to phonons

Nonequilibrium interplay between charge, spin, and lattice degrees of freedom on a square lattice is studied for a single charge carrier doped in the t-J-Holstein model. In the presence of a static electric field we calculate the quasistationary state. With increasing electron-phonon (e-ph) coupling the carrier mobility decreases; however, we find increased steady state current due to e-ph coupling in the regime of negative differential resistance. We explore the distribution of absorbed energy between the spin and the phonon subsystem. For model parameters as relevant for cuprates, the majority of the gained energy flows into the spin subsystem.

Continuous generation of spinmotive force in a patterned ferromagnetic film

We study, both experimentally and theoretically, the generation of a dc spinmotive force. By exciting a ferromagnetic resonance of a comb-shaped ferromagnetic thin film, a continuous spinmotive force is generated. Experimental results are well reproduced by theoretical calculations, offering a quantitative and microscopic understanding of this spinmotive force.

Long-range spin Seebeck effect and acoustic spin pumping

Imagine that a metallic wire is attached to a part of a large insulator, which itself exhibits no magnetization. It seems impossible for electrons in the wire to register where the wire is positioned on the insulator. Here we found that, using a Ni₈₁Fe₁₉/Pt bilayer wire on an insulating sapphire plate, electrons in the wire recognize their position on the sapphire. Under a temperature gradient in the sapphire, surprisingly, the voltage generated in the Pt layer is shown to reflect the wire position, although the wire is isolated both electrically and magnetically. This non-local voltage is due to the coupling of spins and phonons: the only possible carrier of information in this system. We demonstrate this coupling by directly injecting sound waves, which realizes the acoustic spin pumping. Our finding provides a persuasive answer to the long-range nature of the spin Seebeck effect, and it opens the door to 'acoustic spintronics' in which sound waves are exploited for constructing spin-based devices.

Electrically tunable spin injector free from the impedance mismatch problem

Injection of spin currents into solids is crucial for exploring spin physics and spintronics. There has been significant progress in recent years in spin injection into high-resistivity materials, for example, semiconductors and organic materials, which uses tunnel barriers to circumvent the impedance mismatch problem; the impedance mismatch between ferromagnetic metals and high-resistivity materials drastically limits the spin-injection efficiency. However, because of this problem, there is no route for spin injection into these materials through low-resistivity interfaces, that is, Ohmic contacts, even though this promises an easy and versatile pathway for spin injection without the need for growing high-quality tunnel barriers. Here we show experimental evidence that spin pumping enables spin injection free from this condition; room-temperature spin injection into GaAs from Ni(81)Fe(19) through an Ohmic contact is demonstrated through dynamical spin exchange. Furthermore, we demonstrate that this exchange can be controlled electrically by applying a bias voltage across a Ni(81)Fe(19)/GaAs interface, enabling electric tuning of the spin-pumping efficiency.

Fatigue Properties for Micro-Sized Ni-P Amorphous Alloy Specimens

Fatigue crack propagation tests at different stress ratios of 0.1 and 0.5 have been performed on microsized Ni-P amorphous alloy specimens to investigate the influence of stress ratio in the crack growth properties of microsized materials. The specimens tested were cantileverbeam-type with dimensions of 10 × 12 × 50 νm3 prepared by focused ion beam machining. Notches with a depth of 3 [m were introduced in all specimens. The entire set of fatigue tests as performed using a newly developed fatigue testing machine in air at room temperature. Fine stripes deduced to be striations were observed on the fatigue fracture surface. Careful measurements of the striation spacings were made. Fatigue crack propagation rate, that is striation spacing, is plotted as a function stress intensity factor range. Fatigue crack propagation rate at stress-ratios of 0.1 and 0.5 in microsized Ni-P amorphous alloy specimens are given by da/dN ∼ 1.3 × 10−8 ΔK;1.16 and da/dN ∼ 3.7 × 10−8 ΔK0.5, respectively. At a given ΔK, crack propagation rate at a stress ratio of 0.5 was higher than that at 0.1. It is considered that a decrease in crack propagation rate at stress ratio of 0.1 is due to adecrease in effective stress intensity factor range ΔKeff, by the effect of crack closure.

Fracture Behavior of Micro-Sized Ni-P Amorphous Alloy Specimens

Fracture behavior of micro-sized Ni-P Amorphous alloy specimens has been investigated using a newly developed mechanical testing machine. Specimens with dimensions of 10 × 12 × 50 μm were prepared by focused ion beam machining. Two types of specimens with different crack geometries were prepared. One specimen has a notch with root radius is 0.25 μtm and the other has a fatigue pre-crack. The shapes of the loaddisplacement curves are different for each type of specimen. The fracture strength of the specimens with a notch is higher than that with a fatigue pre-crack and the fracture surfaces of the specimens are also different for each type of specimen. This may be due to the difference in stress concentration at the crack (notch) tip, and indicates that even a notch with a root radius of 0.25 μm is not able to be regarded as a crack for micro-sized specimens. Therefore, the introduction of a fatigue pre-crack is essential for the evaluation of fracture toughness for such micro-sized specimens.

Surface-assisted spin Hall effect in Au films with Pt impurities

We show, both experimentally and theoretically, a novel route to obtain giant room temperature spin-Hall effect due to surface-assisted skew scattering. In the experiment, we report the spin-Hall effect in Pt-doped Au films with different thicknesses t(N). The giant spin-Hall angle γ(S)=0.12±0.04 is obtained for t(N)=10 nm at room temperature, while it is much smaller for the t(N)=20 nm sample. Combined ab initio and quantum Monte Carlo calculations for the skew scattering due to a Pt impurity show γ(S)≅0.1 on the Au (111) surface, while it is small in bulk Au. The quantum Monte Carlo results show that the spin-orbit interaction of the Pt impurity on the Au (111) surface is enhanced, because the Pt 5d levels are lifted to the Fermi level due to the valence fluctuation. In addition, there are two spin-orbit interaction channels on the Au (111) surface, while only one in bulk Au.

Spin Seebeck insulator

Thermoelectric generation is an essential function in future energy-saving technologies. However, it has so far been an exclusive feature of electric conductors, a situation which limits its application; conduction electrons are often problematic in the thermal design of devices. Here we report electric voltage generation from heat flowing in an insulator. We reveal that, despite the absence of conduction electrons, the magnetic insulator LaY(2)Fe(5)O(12) can convert a heat flow into a spin voltage. Attached Pt films can then transform this spin voltage into an electric voltage as a result of the inverse spin Hall effect. The experimental results require us to introduce a thermally activated interface spin exchange between LaY(2)Fe(5)O(12) and Pt. Our findings extend the range of potential materials for thermoelectric applications and provide a crucial piece of information for understanding the physics of the spin Seebeck effect.

Hyperuricemia as a risk factor for progressive renal insufficiency after coronary intervention in patients with chronic kidney disease

The development of renal insufficiency after percutaneous coronary intervention (PCI) is associated with increases in morbidity and mortality. Recent studies have reported that hyperuricemia (HU) results in hypertension, intrarenal vascular disease, and renal injury. We postulated that HU contributes to progressive renal disease after PCI. We studied 139 patients with chronic kidney disease (CKD) undergoing elective PCI including 59 HU patients. We assessed the relationship between HU and the development of renal insufficiency after PCI by estimating traditional contrast-induced nephropathy (CIN) and persistent postprocedural nephropathy (PPN) defined as an increase in creatinine ≥0.2 mg/dl of the baseline value 2 weeks after procedure. CIN and PPN were seen in 6.5 and 28.8% respectively. The incidence of PPN was higher in HU patients than in non-HU patients (p < 0.001) although the incidence of CIN was not significantly different between the two groups. PPN was more frequently observed in hyperuricemic patients irrespective of association with hypertension (with and without hypertension, p < 0.001 and p = 0.034, respectively). By univariate analysis, HU and hypertension are associated with PPN although there was no significant predictor of CIN in this study. Multivariate analysis showed HU and hypertension were independent predictors of PPN. HU is a predictor of slow and mild development of renal insufficiency after PCI in patients with CKD.

Spatially homogeneous ferromagnetism of (Ga, Mn)As

Mn-doped GaAs is a ferromagnetic semiconductor, widely studied because of its possible application for spin-sensitive 'spintronics' devices. The material also attracts great interest in fundamental research regarding its evolution from a paramagnetic insulator to a ferromagnetic metal. The high sensitivity of its physical properties to preparation conditions and heat treatments and the strong doping and temperature dependencies of the magnetic anisotropy have generated a view in the research community that ferromagnetism in (Ga, Mn)As may be associated with unavoidable and intrinsic strong spatial inhomogeneity. Muon spin relaxation (muSR) probes magnetism, yielding unique information about the volume fraction of regions having static magnetic order, as well as the size and distribution of the ordered moments. By combining low-energy muSR, conductivity and a.c. and d.c. magnetization results obtained on high-quality thin-film specimens, we demonstrate here that (Ga, Mn)As shows a sharp onset of ferromagnetic order, developing homogeneously in the full volume fraction, in both insulating and metallic films. Smooth evolution of the ordered moment size across the insulator-metal phase boundary indicates strong ferromagnetic coupling between Mn moments that exists before the emergence of fully itinerant hole carriers.

Bipolaron in the t-J model coupled to longitudinal and transverse quantum lattice vibrations

We explore the influence of two different polarizations of quantum oxygen vibrations on the spacial symmetry of the bound magnetic bipolaron in the context of the t-J model by using exact diagonalization within a limited functional space. Linear as well as quadratic electron-phonon coupling to transverse polarization stabilize d-wave symmetry. The existence of a magnetic background is essential for the formation of a d-wave bipolaron state. With increasing linear electron-phonon coupling to longitudinal polarization the symmetry of a d-wave bipolaron state changes to a p wave. Bipolaron develops a large anisotropic effective mass.

Observation of the spin Seebeck effect

The generation of electric voltage by placing a conductor in a temperature gradient is called the Seebeck effect. Its efficiency is represented by the Seebeck coefficient, S, which is defined as the ratio of the generated electric voltage to the temperature difference, and is determined by the scattering rate and the density of the conduction electrons. The effect can be exploited, for example, in thermal electric-power generators and for temperature sensing, by connecting two conductors with different Seebeck coefficients, a device called a thermocouple. Here we report the observation of the thermal generation of driving power, or voltage, for electron spin: the spin Seebeck effect. Using a recently developed spin-detection technique that involves the spin Hall effect, we measure the spin voltage generated from a temperature gradient in a metallic magnet. This thermally induced spin voltage persists even at distances far from the sample ends, and spins can be extracted from every position on the magnet simply by attaching a metal. The spin Seebeck effect observed here is directly applicable to the production of spin-voltage generators, which are crucial for driving spintronic devices. The spin Seebeck effect allows us to pass a pure spin current, a flow of electron spins without electric currents, over a long distance. These innovative capabilities will invigorate spintronics research.

Unusually small electrical resistance of three-dimensional nanoporous gold in external magnetic fields

We report the electric conductivity of three-dimensional (3D) nanoporous gold at low temperatures and in strong magnetic fields. It was found that topologically disordered 3D nanoporosity leads to extremely low magnetoresistance and anomalous temperature dependence as the characteristic length of nanoporous gold is tuned to be approximately 14 nm. This study underscores the importance of 3D topology of a nanostructure on electronic transport properties and has implications in manipulating electron transport by tailoring 3D nanostructures.

Twin hook fixation for proximal femoral fractures

PURPOSE

To report results of twin hook fixation for proximal femoral fractures in comparison to those fixed with the conventional lag screw.

METHODS

Between August 2005 and July 2006, 2 men and 15 women aged 74 to 94 (mean, 85) years with proximal femoral fractures underwent open reduction and internal fixation using the twin hook system. The tip-apex distance was compared with that in 20 patients treated with the sliding hip screw between August 2004 and July 2005.

RESULTS

In the 17 patients, the hook was inserted into the centre of the femoral head. Bone union was achieved and no intra- or post-operative cut-out or device failure was encountered. In patients using the twin hook and sliding hip screw respectively, the mean tip-apex distance was 22.3 mm and 14.6 mm (p<0.001).

CONCLUSION

Using the twin hook system requires more surgical skill than using the sliding hip screw, because failure to insert the pin into the centre of the femoral head risks intra-articular perforation by the hooks.

Electric manipulation of spin relaxation using the spin Hall effect

Using the spin Hall effect, magnetization relaxation in a Ni_{81}Fe_{19}/Pt film is manipulated electrically. An electric current applied to the Pt layer exerts spin torque on the entire magnetization of the Ni81Fe19 layer via the macroscopic spin transfer induced by the spin Hall effect and modulates the magnetization relaxation in the Ni81Fe19 layer. This method allows us to tune the magnetization dynamics regardless of the film size without applying electric currents directly to the magnetic layer.

Endoscopic mucosal resection for early gastric cancer: comparison of two modifications of the cap method

BACKGROUND AND STUDY AIM

Endoscopic mucosal resection using a cap (EMR-C) is an established method for curative resection of early neoplastic lesions; prelooping of the snare may however be difficult and lead to imprecise resection. We therefore compared two modifications of the conventional technique using outer snare placement with an accessory channel in a prospective, nonrandomized study.

PATIENTS AND METHODS

Between October 2004 and March 2007, 54 patients (men 37, women 17; mean age 71 years) underwent EMR. One method involved an internally retained snare (IRS) cap, with a fixed prelooped snare inside the cap; the other method used an externally guided snare (EGS) cap with the snare guided over an oblique cap. The main outcome parameters were specimen size, en bloc resection, and complications.

RESULTS

There was no difference between use of the IRS and EGS cap methods in relation to specimen size (27.6 vs. 27.1 mm), or rates of en bloc resection (88.9 % vs. 83.3 %); only one perforation occurred, and this was in the EGS group.

CONCLUSION

Both techniques appeared to provide similar efficacy, the inner rim of the IRS cap stabilizes aspiration of the lesion compared with the EGS cap that does not have it.

[Long term outcome of arterial switch surgery for transposition of the great arteries: evaluation of the reconstruction of the pulmonary artery]

We assessed the effect of reconstructing the pulmonary artery during arterial switch surgery for transposition of the great arteries on late pulmonary stenosis. Sixty-five patients who underwent Lecompte procedure between September 1991 and December 2006 were divided, by the procedure used chronologically to reconstruct the pulmonary artery, into group XP (single pantaloon patch with equine pericardium, n = 11), group P (direct reconstruction, n = 47), and group AP (single pantaloon patch with fresh autopericardium, n = 7). Outcome and pulmonary stenosis on the most recent ultrasound cardiography (UCG) were compared in the 3 groups. The median follow-up was 13, 7.5, and 1.3 years, respectively. Both early and late mortalities were 1.5% (1/65). Although percutaneous trans-pulmonary angioplasty was necessary in 1, 13, and 3 patients, there was 1, 1, and 0 reoperation for pulmonary stenosis in the 3 groups, respectively. Pulmonary stenosis (pulmonary arterial maximum flow velocity > 3 m/sec on UCG) was present in 4 (40%). 14 (30%). and 3 patients (43%). Although there was no significant difference among the 3 procedures in preventing pulmonary stenosis 10 years after arterial switch surgery, direct reconstruction of the pulmonary artery may show a superior outcome, in particular, over 10 years after arterial switch surgery.

Back extensor strength and lumbar spinal mobility are predictors of quality of life in patients with postmenopausal osteoporosis

To assess the effect of multiple factors on quality of life (QOL) in osteoporosis, relationships between the QOL and possible spinal factors were analyzed in 174 postmenopausal women with osteoporosis. Back extensor strength and lumbar spinal mobility were the most important factors for QOL in these patients.

INTRODUCTION

Quality of life (QOL) in patients with osteoporosis and vertebral fractures is impaired by the decline of total spinal mobility, although it is not clear to what extent. This study aimed to assess the effect of multiple factors on QOL in patients with osteoporosis.

METHODS

QOL of 174 postmenopausal women with osteoporosis (mean, 68 years old) was evaluated using the Japanese Osteoporosis QOL Questionnaire (JOQOL). Correlations between the JOQOL score, bone mineral density (BMD) of the lumbar spine/proximal femur/whole body, the kyphosis angle and mobility of thoracic and lumbar spine, the number of vertebral fractures, grip strengths of dominant and non-dominant hands, and isometric back extensor strength (BES) were analyzed.

RESULTS

JOQOL showed significant correlation (p < 0.05) with age (r = -0.303), BES (r = 0.455), dominant and non-dominant grip strengths (r = 0.273 and r = 0.255, respectively), number of vertebral fractures (r = -0.282), BMDs of proximal femur and whole body (r = 0.200 and r = 0.157, respectively), lumbar kyphosis angle (r = -0.296), and lumbar spinal mobility (r = 0.345). Multiple regression analysis revealed that the BES and lumbar spinal mobility were the significant contributors to the JOQOL (p < 0.05).

CONCLUSION

BES and lumbar spinal mobility are the important factors for QOL in patients with postmenopausal osteoporosis.

Effect of low-intensity back exercise on quality of life and back extensor strength in patients with osteoporosis: a randomized controlled trial

Randomized controlled study in 80 postmenopausal women with osteoporosis was conducted to investigate the effect of a home-based, simple, low-intensity exercise. Low-intensity back-strengthening exercise was effective in improving the quality of life and back extensor strength.

INTRODUCTION AND HYPOTHESIS

Back-strengthening exercise is effective in increasing back extensor strength and decreasing risk of vertebral fractures. We hypothesized that a home-based, simple, low-intensity exercise could enhance back extensor strength and improve the quality of life and/or spinal range of motion in postmenopausal women in a short-term follow-up.

METHODS

Eighty postmenopausal women with osteoporosis were randomly assigned to a control group (n = 38) or an exercise group (n = 42). Subjects were instructed to lift their upper trunk from a prone position antigravity and maintain the neutral position. Isometric back extensor strength, spinal range of motion, and scores for quality of life were evaluated at baseline and 4 months.

RESULTS

Back extensor strength significantly increased both in the exercise group (26%) and in the control group (11%). Scores for quality of life increased in the exercise group (7%), whereas it remained unchanged in the control group (0%). There was a significant difference in quality of life score between the groups (p = 0.012).

CONCLUSIONS

Low-intensity back-strengthening exercise was effective in improving the quality of life and back extensor strength in patients with osteoporosis.