Influence of skew and cross-coupling on flux-weakening performance of permanent-magnet brushless AC machines

A method is proposed for predicting the flux-weakening performance of permanent-magnet (PM) brushless ac machines accounting for skew and d-q axis cross-coupling. The method is based on a d-q-axis flux-linkage model, a hybrid 2-D finite-element (FE)-analytical method being used to predict the d- and q-axis inductances. However, it only requires 2-D FE analysis of the magnetic field distribution over a cross section of the machine. The developed method is used to predict the torque-speed characteristic of an interior PM brushless ac machine with one stator slot-pitch skew. This is compared with predictions from a direct FE analysis of the machine and validated by measurements

Retinal S-antigen Th1 cell epitope mapping in patients with Behcet's disease

Background - Retinal S-antigen (S-Ag) is a most characterized autoantigen of autoimmune uveitis. The recognized immunodominant epitope of human S-Ag in patients with uveitis has not been identified. In this study, we selected certain patients with active uveitis to map the Th1 cell epitope spectrum of human S-Ag in Behcet's disease(BD). Methods - Blood samples were taken from eight active BD patients who showed an immune response to 40 mixed overlapping peptides spanning the entire sequence of human S-Ag. Peripheral blood mononuclear cells were isolated and stimulated with single S-Ag peptide at 5 mu g/ml or 20 mu g/ml. Single-cell immune responses were measured by IFN-gamma ELIspot assay. Results - BD patients heterogeneously responded to the S-Ag peptides at two concentrations. In general, the responses to 5 mu g/ml peptides were slightly stronger than those to 20 mu g/ml peptides, while the maximum SFC frequency to single peptide at the two concentrations was similar. Several peptides including P31, P35 and P40 induced a prominent response, with the frequency of S-Ag specific cells being about 0.007%. Significant reactivity pattern shift was noted in patients with different disease courses. Conclusions - Certain active BD patients have S-Ag specific Th1 cells with a low frequency. The S-Ag epitope specificity between patients is highly heterogeneous, and varies with the uveitis cours

Interaction of the S6 Proline Hinge with N-Type and C-Type Inactivation in Kv1.4 Channels

AbstractSeveral voltage-gated channels share a proline-valine-proline (proline hinge) sequence motif at the intracellular side of S6. We studied the proline hinge in Kv1.4 channels, which inactivate via two mechanisms: N- and C-type. We mutated the second proline to glycine or alanine: P558A, P558G. These mutations were studied in the presence/absence of the N-terminal to separate the effects of the interaction between the proline hinge and N- and C-type inactivation. Both S6 mutations slowed or removed N- and C-type inactivation, and altered recovery from inactivation. P558G slowed activation and N- and C-type inactivation by nearly an order of magnitude. Sensitivity to extracellular acidosis and intracellular quinidine binding remained, suggesting that transmembrane communication in N- and C-type inactivation was preserved, consistent with our previous findings of major structural rearrangements involving S6 during C-type inactivation. P558A was very disruptive: activation was slowed by more than an order of magnitude, and no inactivation was observed. These results are consistent with our hypothesis that the proline hinge and intracellular S6 movement play a significant role in inactivation and recovery. Computer modeling suggests that both P558G and P558A mutations modify early voltage-dependent steps and make a final voltage-insensitive step that is rate limiting at positive potentials

Crystal structure, magnetic properties, and the magnetocaloric effect of Gd5Rh4 and GdRh

The crystal structures of Gd5Rh4 and GdRh have been studied by powder and single crystal x-ray diffraction. The results show that Gd5Rh4 is isotypic with Pu5Rh4 and the bond length of the short Rh-Rh dimer is 2.943(4) Å. According to heat capacity measurements in zero magnetic field, the magnetic ordering temperature of Gd5Rh4 is 13 K, in agreement with magnetization measurements. Both the heat capacity peak shape and the positive slope of the Arrott plots at Curie temperature (TC) indicate the second-order nature of the magnetic transition. The temperature dependence of magnetization of Gd5Rh4 measured in 1 kOe applied field indicates noncollinear magnetic ordering that may change into nearly collinear ferromagnetic ordering by increasing the magnetic field. GdRh is ferromagnetic below T C  = 22 K. Moderate magnetocaloric effects and relatively high refrigerant capacities are observed in Gd5Rh4 and GdRh

Topological Phase Transition and Electrically Tunable Diamagnetism in Silicene

Silicene is a monolayer of silicon atoms forming a honeycomb lattice. The lattice is actually made of two sublattices with a tiny separation. Silicene is a topological insulator, which is characterized by a full insulating gap in the bulk and helical gapless edges. It undergoes a phase transition from a topological insulator to a band insulator by applying external electric field. Analyzing the spin Chern number based on the effective Dirac theory, we find their origin to be a pseudospin meron in the momentum space. The peudospin degree of freedom arises from the two-sublattice structure. Our analysis makes clear the mechanism how a phase transition occurs from a topological insulator to a band insulator under increasing electric field. We propose a method to determine the critical electric field with the aid of diamagnetism of silicene. Diamagnetism is tunable by the external electric field, and exhibits a singular behaviour at the critical electric field. Our result is important also from the viewpoint of cross correlation between electric field and magnetism. Our finding will be important for future electro-magnetic correlated devices.Comment: 4 pages,5 figure

Supersymmetry in carbon nanotubes in a transverse magnetic field

Electron properties of Carbon nanotubes in a transverse magnetic field are studied using a model of a massless Dirac particle on a cylinder. The problem possesses supersymmetry which protects low energy states and ensures stability of the metallic behavior in arbitrarily large fields. In metallic tubes we find suppression of the Fermi velocity at half-filling and enhancement of the density of states. In semiconducting tubes the energy gap is suppressed. These features qualitatively persist (although to a smaller degree) in the presence of electron interactions. The possibilities of experimental observation of these effects are discussed.Comment: A new section on electron interaction effects added and explanation on roles of supersymmetry expanded. Revtex4, 6 EPS figure file

Evolutionary pathways to NS5A inhibitor resistance in genotype 1 hepatitis C virus

Direct-acting antivirals (DAAs) targeting NS5A are broadly effective against hepatitis C virus (HCV) infections, but sustained virological response rates are generally lower in patients infected with genotype (gt)-1a than gt-1b viruses. The explanation for this remains uncertain. Here, we adopted a highly accurate, ultra-deep primer ID sequencing approach to intensively study serial changes in the NS5A-coding region of HCV in gt-1a- and gt-1b-infected subjects receiving a short course of monotherapy with the NS5A inhibitor, elbasvir. Low or undetectable levels of viremia precluded on-treatment analysis in gt-1b-infected subjects, but variants with the resistance-associated substitution (RAS) Y93H in NS5A dominated rebounding virus populations following cessation of treatment. These variants persisted until the end of the study, two months later. In contrast, while Y93H emerged in multiple lineages and became dominant in subjects with gt-1a virus, these haplotypes rapidly decreased in frequency off therapy. Substitutions at Q30 and L31 emerged in distinctly independent lineages at later time points, ultimately coming to dominate the virus population off therapy. Consistent with this, cell culture studies with gt-1a and gt-1b reporter viruses and replicons demonstrated that Y93H confers a much greater loss of replicative fitness in gt-1a than gt-1b virus, and that L31M/V both compensates for the loss of fitness associated with Q30R (but not Y93H) and also boosts drug resistance. These observations show how differences in the impact of RASs on drug resistance and replicative fitness influence the evolution of gt-1a and gt-1b viruses during monotherapy with an antiviral targeting NS5A. © 2018 Elsevier B.V

Protection induced by simultaneous subcutaneous and endobronchial vaccination with BCG/BCG and BCG/adenovirus expressing antigen 85A against Mycobacterium bovis in cattle

The incidence of bovine tuberculosis (bTB) in the GB has been increasing since the 1980s. Immunisation, alongside current control measures, has been proposed as a sustainable measure to control bTB. Immunisation with Mycobacterium bovis bacillus Calmette-Guerin (BCG) has been shown to protect against bTB. Furthermore, much experimental data indicates that pulmonary local immunity is important for protection against respiratory infections including Mycobacterium tuberculosis and that pulmonary immunisation is highly effective. Here, we evaluated protection against M. bovis, the main causative agent of bTB, conferred by BCG delivered subcutaneously, endobronchially or by the new strategy of simultaneous immunisation by both routes. We also tested simultaneous subcutaneous immunisation with BCG and endobronchial delivery of a recombinant type 5 adenovirus expressing mycobacterial antigen 85A. There was significantly reduced visible pathology in animals receiving the simultaneous BCG/BCG or BCG/Ad85 treatment compared to naïve controls. Furthermore, there were significantly fewer advanced microscopic granulomata in animals receiving BCG/Ad85A compared to naive controls. Thus, combining local and systemic immunisation limits the development of pathology, which in turn could decrease bTB transmission

Determination of third-order nonlinear optical susceptibilities of polysilane thin films

Third-order nonlinear optical susceptibilities χ(3)(−3ω; ω, ω, ω) have been measured by third-harmonic generation for thin films of a series of polysilane polymers and copolymers and polycarbosilanes with different alkyl and aryl side groups. χ(3)(−3ω; ω, ω, ω) values for all the polymers studied were found to be in the range 0.3 × 10−12–4.5 × 10−12 esu. Factors affecting the magnitude of χ(3), including the nature of the substituents, Si sequence length, polymer conformation, and film preparation, are discussed

Transition from fractal to non-fractal scalings in growing scale-free networks

Real networks can be classified into two categories: fractal networks and non-fractal networks. Here we introduce a unifying model for the two types of networks. Our model network is governed by a parameter $q$. We obtain the topological properties of the network including the degree distribution, average path length, diameter, fractal dimensions, and betweenness centrality distribution, which are controlled by parameter $q$. Interestingly, we show that by adjusting $q$, the networks undergo a transition from fractal to non-fractal scalings, and exhibit a crossover from `large' to small worlds at the same time. Our research may shed some light on understanding the evolution and relationships of fractal and non-fractal networks.Comment: 7 pages, 3 figures, definitive version accepted for publication in EPJ