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Based on the density functional theory, we investigate the electronic and magnetic properties of various types of defect complexes formed by dopant Tm and Ga vacancies, N vacancies, or O interstitial in Tm-doped GaN. Formation energies are first calculated for all defect complexes to assess their stability. The single Tm dopant is found to introduce the local magnetic moment of about 2 μB/Tm in GaN. However, in the case of defect complexes, the magnetic moments of Tm can be suppressed by the existence of Ga vacancies around it, while the presence of N vacancies or O interstitial does not influence the magnetic moment of Tm. In addition, each Ga vacancy in the neutral charge state induces the local magnetic moment of about 2.1 μB and one octahedral O interstitial can lead to the local moment of about 1.6 μB. [ABSTRACT FROM AUTHOR]

Fe48Co52 nanowire arrays with various diameters and interpore distances were fabricated by electrochemical deposition. The dependences of the permanent magnetic properties on the diameter and interpore distance of the nanowire were investigated. The magnetic dipolar interaction among nanowires was employed to explain the experimental results. After annealing at 550 °C, the excellent permanent magnetic properties were obtained. The coercivity Hc is 3.99 kOe, the squareness Mr/Ms is 0.96, and the maximum energy product of the whole composite film (BH)mf is estimated to be 7.1 MGOe, which avails Fe–Co nanowire arrays prospective as a kind of potential permanent magnet film. [ABSTRACT FROM AUTHOR]

Aims Parkinson disease ( PD) is a common neurodegenerative disease. The aim of this study was to evaluate the risk of PD in patients with organophosphate ( OP) or carbamate ( CM) poisoning by using the Taiwan National Health Insurance Research Database. Methods We conducted a retrospective study involving a cohort of 45 594 patients (9128 patients with a history of OP or CM poisoning and 36 466 control patients) who were selected from the Taiwan National Health Insurance Research Database. The patients were observed for a maximum of 12 years to determine the rates of new-onset PD, and a Poisson regression model was used to identify the predictors of PD. The cumulative incidence of PD between the two cohorts was plotted through Kaplan-Meier analysis. Results During the study period, the incidence rate ratio ( IRR) of PD in the OP or CM poisoning patients was 1.36-fold [95% confidence interval ( CI)=1.26-1.47] higher than that in the control patients in the multivariable model. The absolute incidence of PD was the highest for the group aged ≥75 years in both cohorts (77.4 vs 43.7 per 10 000 person-years). However, the age-specific relative risk was higher for the group aged <50 years (adjusted IRR=3.88; 95% CI=3.44-4.39). Conclusion Our results suggest that the likelihood of developing PD is greater in patients with OP or CM poisoning than in those without poisoning. OP or CM poisoning may be an independent risk factor for PD. [ABSTRACT FROM AUTHOR]

To probe the origin of p-type conductivity in Sb-doped ZnO, a careful and detailed synchrotron radiation study was performed. The extended X-ray absorption fine structure and X-ray photoelectron spectroscopy investigations provided the evidence for the formation of the complex defects comprising substitution Sb ions at Zn sites (SbZn) and Zn vacancies within the Sb-doped ZnO lattice. Such complex defects result in the increases of Sb-O coordination number and the Sb valence and thereby lead to the p-type conductivity of Sb-doped ZnO. The back-gate field-effect-transistors based on single nanorod of Sb-doped ZnO were constructed, and the stable p-type conduction behavior was confirmed. [ABSTRACT FROM AUTHOR]

The authors present novel high-performance polariser designs. The polarisers provide perfect linear-to-circular polarisation transformation without insertion loss at the centre frequency. Four designs are discussed for use in two situations. In the first situation, a polariser is inserted into an isotropic medium and, in the second, a polariser is sandwiched between two isotropic media with different intrinsic impedances. For the first situation, two designs are proposed based on the dielectric window and impedance matching. For the second, two further designs are proposed. In the first, two anisotropic media are cascaded in a special manner to perform the polarisation transformation without insertion loss. For a simpler uniaxial medium, the design utilises an impedance transformer and the polariser mentioned in the first situation. One of the resulting polarisers has an infinite transmission bandwidth, if the medium is nondispersive. Hence, the bandwidth of the polariser is solely determined by the axial ratio bandwidth. Based on the two-transmission-lines model, the polariser can be examined easily using commercial radio-frequency software. Some examples and simulated results are presented to validate these designs. [ABSTRACT FROM AUTHOR]

Single-phase PbPd0.81Co0.19O2 film with a body-centered orthorhombic structure was prepared using the sol-gel spin-coating technique and an oxidation treatment. Film resistivity has a power dependence on temperature. The insulator-metal transition temperature was 358 K, markedly higher than the reported values of similar material systems. Ferromagnetism and superparamagnetism coexisted in the film and the ferromagnetism persisted up to 380 K. As temperature increased, the notable increasing tendencies were found for the film's saturation magnetization and for the magnetic field where saturation magnetization decreases abruptly. The special spin gapless band structure and the film's nanograin microstructure are likely responsible for these interesting properties. [ABSTRACT FROM AUTHOR]

By combining the first-principles with Monte Carlo method, we investigate the magnetic exchange interactions and the magnetic entropy changes in the vicinity of the second-order transition in Ni2Mn1.4In0.6(R)(R=Si, Ge, Al) alloys with R substituting for In atoms. The results show that the substitution of R for In atoms can lead to the reduction of the Curie temperature and an increase in the total magnetic moments of the systems. The Si substitution gives rise to the increase in the magnetic entropy changes, whereas the Ge and Al substitutions make the entropy change decrease. In addition, our calculated Curie temperatures for Ni2Mn1.4In0.6-xSix(x=0.04,0.08,0.12,0.16) are in good agreement with available experimental results. [ABSTRACT FROM AUTHOR]

A compact dual-band insulator for multiple-input, multiple-output (MIMO) antennas is presented. The capacitively loaded loops are designed for different operating frequencies and printed on both sides of the substrate of the MIMO antenna of the portable devices. When the proposed insulators are inserted in between MIMO antennas, the isolation shows good improvement at both 2.6 and 3.5 GHz bands. The isolation is suppressed under -20 dB at the lower band of 2550-2730 MHz and at the upper band of 3390-3820 MHz. The proposed insulators are also validated through measurements. [ABSTRACT FROM AUTHOR]

Based on the density functional theory, we systematically investigate the stability and magnetic moment of various defect complexes, which are formed by Gd and Ga vacancies, N vacancy, N interstitial, or O interstitial in GaN doped with Gd. The point defects and dopant Gd are found to attract each other, i.e., cooperative effect, which means that defects would make it relatively easy to incorporate Gd into GaN. However, the formation of defects, especially Ga vacancies in GaN:Gd, is not energetically stable. The more discretely Ga vacancies distribute, the larger is the local magnetic moment that they can introduce in GaN:Gd. In comparison, N vacancies do not contribute to the local magnetic moment irrespective of their concentration and symmetry. For the case of the interstitial atom, the octahedral N can induce the local magnetic moment, while the tetrahedral N or O sites would not contribute to the local magnetic moment. Only the octahedral O near the Gd is found to induce the magnetic moment. [ABSTRACT FROM AUTHOR]

Fe–Si–Cr–B amorphous and carbonyl-iron powders insulated with phosphoric acid solution were used to prepare soft magnetic composites. The mass ratios of phosphoric acid insulation solution and the carbonyl-iron powder dependences of the magnetic spectrum, the density, and the resistivity were studied. Both the real part and the imaginary part of the core's complex permeability increased after an initial decrease with the acid mass ratio increasing. This is similar to the variation tendency of the core's density and opposite to the variation tendency of the core's resistivity. The amount of the air gap, reflected by the density, was proposed to be the most important factor that has a great influence on the composite's magnetic properties. The increase of the air gap reduced the effective demagnetizing field and the resistivity. This improved the permeability and the hysteresis loss and deteriorated the eddy-current loss. Carbonyl-iron powder addition was found to improve the moldability and the permeability of the composite based on the Fe-Si-Cr-B amorphous powder, although its loss was higher than that of the amorphous powder. All these findings can be referenced when designing an amorphous-based soft magnetic composite (SMC) core with balanced permeability, loss, and cost for high-frequency inductor within a MHz band. [ABSTRACT FROM AUTHOR]

Fe-6.5wt%Si soft magnetic powder cores were prepared by using an improved bluing insulation method. A high-quality oxide insulation layer with good temperature stability was found to distribute continuously in the intervals between the Fe-Si particles. The effects of the annealing temperature and the compaction pressure on the core’s magnetic properties were investigated in detail. It was found that high temperature and low compaction pressure are beneficial to decrease the core’s inner stress and high compaction pressure is helpful to reduce the air gap. All the variations of the magnetic performance for the powder cores discussed in this paper were explained reasonably by considering these two factors. From the point of view of low loss, 760 °C and 2090 MPa were confirmed to be the relatively best annealing temperature and compaction pressure, respectively. The μe, the % μe at 100 Oe, and the loss at 50 kHz/1000 Gs for the core prepared under these two conditions are 63.57, 72.82%, and 547.66 mW/cm3, respectively. [ABSTRACT FROM AUTHOR]

A new design of a circularly polarised square slot antenna loaded with a cross patch is presented. A cross patch inclined diagonally with respect to the square slot is placed at the centre of the square slot. By choosing proper dimensions of the cross patch, two orthogonal resonant modes with a 90° phase difference for circular polarisation can be excited and feed the square slot antenna using a 50 Ω CPW with a protruded signal strip. 10 dB return loss bandwidth of 846 MHz (39.6%) and 3 dB axial ratio bandwidth of 240 MHz (12.4%) for the proposed antenna are achieved. Gain variation within the CP bandwidth is observed to be less than 1 dB. [ABSTRACT FROM AUTHOR]

Ketamine, an N-methyl-D-aspartate receptor (NMDAR) channel blocker, has been found to induce rapid and robust antidepressant-like effects in rodent models and in treatment-refractory depressed patients. However, the marked acute psychological side effects of ketamine complicate the interpretation of both preclinical and clinical data. Moreover, the lack of controlled data demonstrating the ability of ketamine to sustain the antidepressant response with repeated administration leaves the potential clinical utility of this class of drugs in question. Using quantitative electroencephalography (qEEG) to objectively align doses of a low-trapping NMDA channel blocker, AZD6765 (lanicemine), to that of ketamine, we demonstrate the potential for NMDA channel blockers to produce antidepressant efficacy without psychotomimetic and dissociative side effects. Furthermore, using placebo-controlled data, we show that the antidepressant response to NMDA channel blockers can be maintained with repeated and intermittent drug administration. Together, these data provide a path for the development of novel glutamatergic-based therapeutics for treatment-refractory mood disorders. [ABSTRACT FROM AUTHOR]

Objective – The clinical differentiation between early Parkinson's disease (PD) and essential tremor (ET) could be difficult, therefore, the aim of this study was to investigate 99mTc-TRODAT-1 SPECT as an applicable tool in this field. Methods – 99mTc-TRODAT-1 single photon emission computed tomography (SPECT) was performed in 10 healthy volunteers, 27 patients with idiopathic PD (Hoehn and Yahr 1–1.5) and 12 patients with ET. The ratio of striatal 99mTc-TRODAT-1 binding was calculated as the index of (striatum − occipital cortex)/occipital cortex. Results – Compared with the striatal 99mTc-TRODAT-1 uptake in the ET group (0.49 ± 0.07) or healthy controls (0.54 ± 0.18), there was a significant decrease in the bilateral striatums of early PD, with a greater reduction in the contralateral striatum (0.27 ± 0.08) than ipsilateral one (0.36 ± 0.10, P < 0.01). Its sensitivity and specificity of differentiating early PD from ET was 96.4% and 91.7% respectively. Conclusion – 99mTc-TRODAT-1 SPECT can detect the dysfunction of nigrostriatal system in patients with early PD and provided a feasible tool to help differentiate early PD from ET. [ABSTRACT FROM AUTHOR]

PrxTb1-xFe1.9 (0≤=x≤=1) magnetostrictive alloys with cubic Laves phase have been synthesized by a high-pressure synthesis method. Crystal structure, magnetic properties, magnetocrystalline anisotropy, and the magnetostriction of PrxTb1-xFe1.9 (0≤=x≤=1) alloys are investigated. Composition anisotropy compensation is realized in Pr0.9Tb0.1Fe1.9 alloy, which shows low magnetocrystalline anisotropy and a large magnetostriction value (λ∥-λ⊥=1497 ppm) at 13 kOe at room temperature. These characters suggest that Pr0.9Tb0.1Fe1.9 alloy may be a promising candidate for magnetostriction application [ABSTRACT FROM AUTHOR]

Nanocrystalline Tb-doped ZnO films have been prepared by ion-beam sputtering technique. Magnetic characterization showed that the films are ferromagnetic with Curie temperature (TC) higher than room temperature. By further treated with a rapid thermal annealing process, both the grain size and the carrier concentration of the films increase, while the saturation magnetization of the films decreases. This magnetic behavior can be hardly explained by either bound magnetic polaron model or free carrier mediation model, thus suggests that the grain boundaries play a key role for the origin of ferromagnetism in these films. [ABSTRACT FROM AUTHOR]