Insight into intrinsic ferromagnetism in quasi-2D Cr5-yTe8.

Cr5Te8is a half metal with 2D van der Waals ferromagnetic structure and its magnetic properties can be tuned by changing the proportionality of Cr and Te. We report an investigation of magnetization and magnetic anisotropy near the critical transition region of a Cr5-yTe8single crystal with the static and dynamic probes, to unravel the nature of field-dependent spin-spin interactions. The magnetic transition temperatureTCincreasing from 255 K (at near zero-field) to 279 K (at 65 kOe along theab-plane) has been identified. Accordingly, a phase diagram of field versus transition temperature has been established. From the analysis of the field dependence of the critical behavior, we provided evidence that the scenario of 2D Heisenberg-type interactions can be employed to interpret the field-dependent magnetic transitions in Te-rich Cr4.8Te8. The precise picture for the field-reduced spin-spin interaction range has been obtained. The conclusion drawn from the present study demonstrated that Cr4.8Te8is a promising candidate for the spintronic applications with a tunable magnetic transition temperature.

Atomic replacement effects on the band structure of doped perovskite thin films.

The potential applications of perovskite manganite R1-xAxMnO3 (R = rare earth element; A = Sr, Ca) thin films have been continuously explored due to their multi-functional properties. In particular, the optimally hole-doped La0.67Ca0.33MnO3 thin film demonstrates a colossal magneto-resistance that is beneficial to the performance of spintronic devices. To understand the effect of R and A ions on the material properties, we systematically measure the resistivity, magnetization, and electronic energy states for three optimally hole-doped R0.67A0.33MnO3 thin films with R = La, Sm and A = Sr, Ca. Various energy parameters are derived based on the X-ray absorption and X-ray photoelectron spectra, including the band gap, the charge frustration energy and the magnetic exchange energy. It is interesting to find that the replacement of La with Sm is more effective than that of Sr with Ca in terms of tuning the electrical property, the Curie temperature, and the band gap. The strain-induced reduction of the O 2p- Mn 3d hybridization and the interplay of R/A site disorder and strain effect are discussed. The results of this study provide useful information for the band design of perovskite oxide films.

Strain effect on orbital and magnetic structures of Mn ions in epitaxial Nd0.35Sr0.65MnO3/SrTiO3 films using X-ray diffraction and absorption.

This study probes the temperature-dependent strain that is strongly correlated with the orbital and magnetic structures of epitaxial films of Nd0.35Sr0.65MnO3 (NSMO) that are fabricated by pulsed laser deposition with two thicknesses, 17 (NS17) and 103 nm (NS103) on SrTiO3 (STO) substrate. This investigation is probed using X-ray diffraction (XRD) and absorption-based techniques, X-ray linear dichroism (XLD) and the X-ray magnetic circular dichroism (XMCD). XRD indicates a significant shift in the (004) peak position that is associated with larger strain in NS17 relative to that of NS103 at both 30 and 300 K. Experimental and atomic multiplet simulated temperature-dependent Mn L3,2-edge XLD results reveal that the stronger strain in a thinner NS17 film causes less splitting of Mn 3d eg state at low temperature, indicating an enhancement of orbital fluctuations in the band above the Fermi level. This greater Mn 3d orbital fluctuation can be the cause of both the enhanced ferromagnetism (FM) as a result of spin moments and the reduced Néel temperature of C-type antiferromagnetism (AFM) in NS17, leading to the FM coupling of the canted-antiferromagnetism (FM-cAFM) state in NSMO/STO epitaxial films at low temperature (T = 30 K). These findings are also confirmed by Mn L3,2-edge XMCD measurements.

Reduced use of emergency care and hospitalization in patients with post-stroke cognitive impairment treated with traditional Chinese medicine.

BACKGROUND: The effect of traditional Chinese medicine (TCM) on the outcomes of dementia remains unclear. Our purpose is to compare the use of emergency care and hospitalization in patients with post-stroke cognitive impairment (PSCI) with or without treatment of TCM. METHODS: In a stroke cohort of 67 521 patients with PSCI aged over 40 years obtained from the 23 million people in Taiwan's national health insurance between 2000 and 2007, we identified 6661 newly diagnosed PSCI patients who were treated with TCM and 6661 propensity score-matched PSCI patients who were not treated with TCM. Under the control of immortal time bias, we calculated the adjusted rate ratios (RRs) and 95% CIs of the 1-year use of emergency care and hospitalization associated with TCM. RESULTS: The means of the emergency care medical visits (0.40 ± 0.98 vs. 0.47 ± 1.01, P = 0.0001) and hospitalization (0.72 ± 1.29 vs. 0.96 ± 1.49, P < 0.0001) were lower in the PSCI patients treated with TCM than in those without the TCM treatment. The RRs of emergency care and hospitalization associated with TCM were 0.87 (95% CI = 0.82-0.92) and 0.81 (95% CI = 0.78-0.84), respectively. The PSCI patients treated with a combination of acupuncture and herbal medicine had the lowest risk of emergency care visits and hospitalization. CONCLUSIONS: Our study raises the possibility that TCM use was associated with reduced use of emergency care and hospitalization after PSCI. However, further randomized clinical trials are needed to provide solid evidence of this benefit and identify the underlying mechanism.

Microstructures and mechanical properties of in situ TiC-ß-Ti-Nb composites with ultrafine grains fabricated by high-pressure sintering.

In this study, an in situ ß-Ti-Nb composites reinforced with TiC particles with an ultrafine grain size were fabricated using a powder metallurgical (PM) method. The microstructures and mechanical properties of the composites were characterized using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and compression tests. TiC particles were formed in the ball-milled powders after annealing at 600 °C due to a chemical reaction between stearic acid and titanium. Using high-pressure sintering (HPS) on an apparatus with six tungsten carbide anvils, a fully dense ß-Ti-Nb composite reinforced with fine in situ TiC particles was obtained. The TiC particles exhibit particle sizes of ~500 nm, uniformly distributed in the composite matrix, which had grain sizes of ~600 nm. Thus, the TiC-ß-Ti-Nb composite show very high compression yield strength and relatively high plasticity contributed by grain refinement and TiC particles strengthening. The composite with 45 vol.% TiC exhibited excellent mechanical properties, with a yield compressive strength of 1990 MPa and plastic strain of 9.12%. More over, a modified rule-of-mixture (ROM) was presented to describe the combined strengthening effect of grain refinement and TiC particles.

Spin pump and probe in lanthanum strontium manganite/platinum bilayers.

Ferromagnetic resonance driven spin pumping (FMR-SP) is a novel method to transfer spin current from the ferromagnetic (FM) layer into the adjacent normal metal (NM) layer in an FM/NM bilayer system. Consequently, the spin current could be probed in NM layer via inverse spin Hall effect (ISHE). In spite of numerous ISHE studies on FM/Pt bilayers, La0.7Sr0.3MnO3(LSMO)/Pt system has been less explored and its relevant information about interface property (characterized by spin mixing conductance) and spin-charge conversion efficiency (characterized by spin Hall angle) is a matter of importance for the possible applications of spintronic devices. In this work, the technique of FMR-SP has been applied on two series of LSMO/Pt bilayers with the thickness of each layer being varied. The thickness dependences of ISHE voltage allow to extract the values of spin mixing conductance and spin Hall angle of LSMO/Pt bilayers, which are (1.8 ± 0.4) × 1019 m-2 and (1.2 ± 0.1) % respectively. In comparison with other FM/Pt systems, LSMO/Pt has comparable spin current density and spin mixing conductance, regardless its distinct electronic structure from other ferromagnetic metals.

Utilization of Western medicine and traditional Chinese medicine among patients with Alzheimer's disease in Taiwan: a nationwide population-based study.

BACKGROUND AND PURPOSE: Large-scale studies of utilization of medical services among patients with Alzheimer's disease (AD) are lacking. We aimed to investigate the usage of Western medicine and traditional Chinese medicine (TCM) among these patients in Taiwan. METHODS: We analyzed one million samples from the National Health Insurance Research Database in Taiwan. Patients (n = 1814) newly diagnosed with AD in 2001-2010 were divided into TCM users (n = 528) and non-TCM users (n = 1286). RESULTS: Compared with non-TCM users, TCM users were younger, had a higher female:male ratio and higher utilization rate of Western medicine. The median interval between diagnosis and the first TCM consultation was 7.92 months. Donepezil and rivastigmine were commonly prescribed medications. Chinese herbal medicine was the most popular treatment among TCM users. CONCLUSIONS: This study revealed the specific usage patterns of TCM and non-TCM medical services among patients with AD. The information could be used for improving the healthcare of patients with AD.

New metal chalcogenides found in MnN-1(Gd2-xInx)SN+2 (N = 3, 4, 5): syntheses, structures, and magnetic properties.

Three new metal chalcogenides have been identified in MnN-1(Gd2-xInx)SN+2 with N = 3, 4, and 5 via a flux-growth synthesis. All compounds crystallize in the same space group of orthorhombic Cmcm with cell constants: Mn2GdInS5 (1), a = 3.789(1) Å, b = 12.411(1) Å, and c = 15.489(1) Å; Mn3Gd2S6 (2), a = 3.778(1) Å, b = 12.505(2) Å, and c = 19.114(2) Å; Mn4Gd2S7 (3), a = 3.769(1) Å, b = 12.466(2) Å, and c = 22.289(3) Å. Compounds 1-3 form a homologous series through the modulation of the MnS unit, whose structures represent a complete system of the corresponding lillianites (N1,N2L) of 3,3L, 4,4L and 5,5L. The gradually wider slabs formed in the series result in a monotonic increase along the c dimensions from 1 to 3. Crystal 3 is the first to achieve a predicted structure of 5,5L. Mn2GdInS5 (1) displays a weak antiferromagnetic (AFM) ordering at 10 K and the Weiss constant (θ) of -0.76 K. Mn2Gd1.5In0.5S5 (1a), an isostructure of 1, shifts the AFM transition temperature to 12 K and possesses a slightly larger θ constant of -6.06 K. Mn4Gd2S7 (3), featuring the thickest slabs in this series, shows a significant antiferromagnetic behavior beginning at a high temperature of 70 K and has a largest θ constant of -40.25 K. A small amount of impurity α-Gd2S3 with an AFM transition temperature around 4 K was characterized in sample 3, which does not interfere with the magnetic ordering of 3 at much higher temperatures. These magnetic chalcogenides display band gaps of 1.66 eV for 1, 1.75 eV for 1a, and 1.44 eV for 3.

Birth month and risk of atopic dermatitis: a nationwide population-based study.

BACKGROUND: An individual's birth month has been associated with allergic diseases, but little is known about the association between birth month and atopic dermatitis (AD). OBJECTIVE: The aim of this study was to investigate the risk of AD in children born in various months. METHODS: Using Taiwan's National Health Insurance Research Database, we conducted a case-control study that included 31 237 AD cases and 124 948 age- and gender-matched controls without AD. Data regarding sociodemographic factors and coexisting medical conditions were collected and controlled in the multivariate logistic regression to determine the adjusted odds ratios and 95% confidence intervals for AD associated with the participant's birth month. RESULTS: Compared with people born in May, people born in December had the highest risk of AD (OR 1.17, 95% CI 1.10-1.25), followed by people born in October (OR 1.15, 95% CI 1.08-1.22) and November (OR 1.13, 95% CI 1.06-1.20). Low income (OR 1.28), asthma (OR 1.88), allergic rhinitis (OR 1.70), psoriasis (OR 2.36), vitiligo (OR 1.99), urticaria (OR 2.14), and systemic lupus erythematosus (OR 1.91) were significant coexisting medical conditions associated with AD. CONCLUSION: Being born in December, October, or November may be associated with an increased risk of AD. Future investigations are needed to evaluate the possible mechanism behind the association between birth month and AD.

Thickness controlled proximity effects in C-type antiferromagnet/superconductor heterostructure.

Modulation of the superconducting state possessing a C-type antiferromagnetic phase in the Nd0.35Sr0.65MnO3/YBa2Cu3O7 heterostructure is investigated, with the Nd0.35Sr0.65MnO3 thickness (t) varying from 40 to 200 nm. Both the superconducting transition temperature and the upper critical field along the c-axis decrease with increasing t; while the in-plane coherence length increases from 2.0 up to 3.6 nm. Meanwhile, the critical current density exhibits a field-independent behavior, indicating an enhanced flux pinning effect. Furthermore, low-temperature spin canting induces a breakdown and re-entrance of the superconductivity, demonstrating a dynamic completion between the superconducting pairing and the exchange field. An unexpected colossal magnetoresistance is observed below the superconducting re-entrance temperature at t = 200 nm, which is attributed to the dominant influence of the exchange field over the pairing energy.

Effect of thermomechanical treatment on the superelasticity of Ti-7.5Nb-4Mo-2Sn biomedical alloy.

Effects of thermomechanical treatment on the microstructure and superelasticity of Ti-7.5Nb-4Mo-2Sn biomedical alloy were investigated by using XRD measurement, optical microscope (OM), transmission electron microscope (TEM) and tensile tests. The titanium alloy samples were prepared by annealing at a temperature in the range of 600 to 1000°C after severe cold rolling; and the samples that were annealed at 800°C were further aged at 600 and 700°C. The volume fraction of α phases decreased while that of ω phases increase with increasing annealing temperature. The αâ†’ß transformation temperature of the alloy was determined to be between 700 and 800°C. The alloy that was annealed at 700°C exhibited a high level of superelasticity with relatively high first yield stress (σSIM) at room temperature because it contained a fine α phase. A certain amount of ω phases also resulted in an increase in σSIM, leading to an improvement in the superelasticity of the alloys that were annealed at 900 and 1000°C. Aging treatment led to the precipitations of α and ω phases in the alloy after annealing at 800°C; and the volume fraction of α phases decreased while that of ω phases increased with increasing aging temperature. Excellent superelasticity with high recovered strain (εrecoverable) and strain recovery rate (η) were obtained in the aged alloy due to the reinforcement of α and ω phases induced by aging treatment. The alloy annealed at 700°C for 0.5h exhibited the best superelasticity in all the thermomechanically treated alloys due to the strengthening from the subgrain refining and the precipitating of fine α phases.

Influence of damping constant on inverse spin hall voltage of La0.7Sr0.3MnO3(x)/platinum bilayers.

Pure spin transport via spin pumping in the condition of ferromagnetic resonance can be transformed to charge current in the ferromagnetic/paramagnetic bilayer systems, based on inverse spin Hall effect (ISHE). Here, we explore La0.7Sr0.3MnO(x)/Pt(5.5 nm) [x = 10 to 65 nm] bilayers to investigate the influence of damping constant on spin pumping efficiency. The results show that the ISHE voltage depend on the damping constant of magnetic moment, suggesting that the precession energy tansferred to lattice/electron of normal metal is a key parameter to control the magnitude of spin current.

Condensation of two-dimensional oxide-interfacial charges into one-dimensional electron chains by the misfit-dislocation strain field.

The success of semiconductor technology is largely ascribed to controlled impacts of strains and defects on the two-dimensional interfacial charges. Interfacial charges also appear in oxide heterojunctions such as LaAlO3/SrTiO3 and (Nd0.35Sr0.65)MnO3/SrTiO3. How the localized strain field of one-dimensional misfit dislocations, defects resulting from the intrinsic misfit strains, would affect the extended oxide-interfacial charges is intriguing and remains unresolved. Here we show the atomic-scale observation of one-dimensional electron chains formed in (Nd0.35Sr0.65)MnO3/SrTiO3 by the condensation of characteristic two-dimensional interfacial charges into the strain field of periodically arrayed misfit dislocations, using chemical mapping and quantification by scanning transmission electron microscopy. The strain-relaxed inter-dislocation regions are readily charge depleted, otherwise decorated by the pristine charges, and the corresponding total-energy calculations unravel the undocumented charge-reservoir role played by the dislocation-strain field. This two-dimensional-to-one-dimensional electronic condensation represents a novel electronic-inhomogeneity mechanism at oxide interfaces and could stimulate further studies of one-dimensional electron density in oxide heterostructures.

Influences of recovery and recrystallization on the superelastic behavior of a ß titanium alloy made by suction casting.

The influences of cold rolling (CR), recovery and recrystallization on the microstructure, mechanical properties and superelasticity of the suction cast Ti-7.5Nb-4Mo-2Sn alloy were investigated. It has been found that, with the increase of the CR thickness reduction rate, the volume fraction of the strain-induced martensite transiting from the ß phase increases. During annealing treatment, the precipitation of α and ω phases occurred at 700 and 800 °C, respectively, and the volume fraction of the α and ω phases increases with increasing CR thickness reduction rate. The high density of dislocations introduced by cold rolling can accelerate the course of α and ω transformation. The cold rolled alloy after annealing at 700 °C exhibits excellent superelasticity with a high first yielding stress (σSIM), a large recoverable strain (εrecoverable) and a high strain recovery rate (η) due to the retention of massive dislocations and α phase precipitates in the recovery process. The grain size shows a strong effect on the martensitic transformation, and the relationship between the critical stress for the martensite transformation and grain size follows the Hall-Petch equation with a slope of approximately 0.27 MN m-3/2.

Superelastic behavior of a ß-type titanium alloy.

The superelasticity of a ß Ti alloy, Ti-7.5Nb-4Mo-2Sn (in atom percent) was evaluated by using loading and unloading cyclic tensile tests under different thermomechanical conditions, and the effects of the plastic deformation, temperature, strain rate and cyclic loading on the superelasticity of the alloy were studied. It is found that, with the applied strain increasing, the stress inducing the reverse martensitic transformation σα″-ß and the strain recovery rate η decreases. The increase of deformation temperature promotes σß-α″, σα″-ß and Δσ, and the temperature dependency of the stresses obeys the Clausius-Clapeyron relation. σß-α″, σα″-ß and Δσ are independent on the strain rate when it is lower than 8.35×10(-4)s(-1). However, when the strain rate is higher than 8.35×10(-4)s(-1), σß-α″ and Δσ increase, but σα″-ß decreased with increasing the strain rate. By cyclic loading and unloading to the maximum strain of 6% at 25°C under the strain rate of 1.67×10(-4)s(-1), the alloy exhibits a improved superelasticity after seventh cycles due to the training effect.

Effect of Sn addition on the microstructure and superelasticity in Ti-Nb-Mo-Sn alloys.

Ti-7.5Nb-4Mo-xSn (x=0-4at%) alloys were developed as the biomedical materials. The effect of the Sn content on the microstructure and superelasticity of the alloys was investigated. It is found that Sn is a strong stabilizer of the ß phase, which is effective in suppressing the formation of α″ and ω phases in the alloys. Moreover, the Sn addition has a significant impact on the mechanical properties of the alloys. With the increase of Sn addition, the yield stress of the alloys increase, but their elastic modulus, the fracture strength and the ductility decrease, and the deformation mode of the alloys changes from (322) twining to α″ transformation and then to slip. The Ti-7.5Nb-4Mo-1Sn and Ti-7.5Nb-4Mo-3Sn alloys exhibit a good superelasticity with a high σ(SIM) due to the relatively high athermal ω phases containing or the solution hardening at room temperature. Under the maximum strain of 5%, Ti-7.5Nb-4Mo-3Sn (at%) alloy exhibits higher super elastic stability than that of Ti-7.5Nb-4Mo-1Sn alloy.

Optical control of phase transformation in Fe-doped TiO2 nanoparticles.

A series of anatase phase Fe-doped TiO2 nanoparticles are prepared by a modified sol-gel method. Spontaneous Raman spectroscopy is utilized to characterize the crystal structures of these nanoparticles and investigate their structural transformation under the exposure of a 532 nm green laser. The anatase phase of TiO2 can be effectively converted into the rutile phase with the assistance of Fe doping. It is found that the critical laser intensity for phase transformation decreases with increasing the Fe content. We ascribe this tendency to the enhanced optical absorption and the photo-induced thermal heating effect, which can be associated with the defect structure within the bandgap of Fe- TiO2 nanoparticles. Our study demonstrates an all-optical approach to pump and probe the phase transformation of metal-doped TiO2 nanoparticles.

HLA-E gene polymorphism associated with susceptibility to Kawasaki disease and formation of coronary artery aneurysms.

OBJECTIVE: Kawasaki disease (KD) is a pediatric systemic vasculitis of unknown cause for which a genetic influence is supposed. The purpose of this study was to identify possible genetic variants in the major histocompatibility complex (MHC) region that are associated with KD and the development of coronary artery aneurysms (CAAs) in a Taiwanese population. METHODS: The 168 genetic variants covering the MHC locus were analyzed in an association study of a Taiwanese cohort of 93 KD patients and 680 unrelated healthy children matched for sex and age with the study patients. RESULTS: Eleven single-nucleotide polymorphisms (SNPs) were associated with the occurrence of KD. The SNP located at the 3'-untranslated region of HLA-E (rs2844724) was highly associated (P < 1 x 10(-7)). In addition, the frequency of the C allele was higher in KD patients without CAAs than in controls (P < 0.001) due to a significantly increased frequency of the CC and CT genotypes. Plasma levels of soluble HLA-E were significantly higher in KD patients than in controls regardless of the presence of CAAs. Furthermore, there was a trend toward higher plasma levels of soluble HLA-E in KD patients with the CT and TT genotypes of the HLA-E gene polymorphism. CONCLUSION: Our results suggest that the HLA-E gene polymorphism may play a role in the pathogenesis of KD.

Inhibitions of mast cell-derived histamine release by different Flos Magnoliae species in rat peritoneal mast cells.

Flos Magnoliae (FM) is a commonly used Chinese medicinal herb for symptomatic relief of allergic rhinitis, sinusitis and headache. A number of FM species have been used as substitutes or adulterants for clinical application, although the differences in their pharmacological actions have not been reported. The present study investigated the effects of six identified FM species M. biondii, M. denudata, M. kobus, M. liliflora, M. sargentiana and M. sprengeri, as well as the marker compounds magnolin and fargesin on compound 48/80-induced histamine release in rat peritoneal mast cells (RPMC) in vitro. Ethanolic extracts of all FM species produced a concentration-dependent inhibition of compound 48/80-induced histamine release in RPMC. The rank order of the IC(50)s was M. biondii