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In this paper, an overmodulation (OVM) technique is proposed based on Fourier analysis. The OVM trajectory is a mixture of six arc segments of the inscribed circle and six vertices of the voltage hexagon. By adjusting the holding angle at each vertex, the modulation index is determined. The fundamental component is expressed as a function of the holding angle, and the linearity with the modulation index is obtained by the inverse relation. This algorithm guarantees seamless transitions from the space vector pulsewidth modulation to OVM and finally to the six-step. Apart from the variable voltage variable frequency control, the proposed algorithm works well with the interior permanent magnet synchronous motor current controller. By computer simulation and experimental evidence, the effectiveness is demonstrated.

Sjögren’s syndrome (SS) is a chronic and systemic autoimmune disease characterized by lymphocytic infiltration in the exocrine glands. Although an association between inflammasome activation in peripheral blood cells and disease activity of SS has been reported, little is known about inflammasome activation in exocrine glands and its underlying mechanisms. We investigated the levels of AIM2, ASC, caspase-1, IL-1β, and IL-18 in salivary gland tissues and saliva from SS patients. We found that AIM2, ASC, Caspase-1, and IL-18 were increased in the saliva from primary SS patients compared with healthy and sicca controls. Numbers of AIM2-ASC speck also were elevated in the salivary gland epithelial cells of SS patients. The expression of caspase-1 correlated with type I interferon (IFN) signature gene expressions in the minor salivary glands (MSG) of SS patients, and was increased by type I IFN stimulation in salivary gland epithelial cells (SGECs). The AIM2 inflammasome was activated in SGECs after stimulation by the AIM2 ligand, poly(dA:dT). In addition, type I IFN accelerated AIM2 inflammasome activation as determined by the increased expression of caspase-1 in SGECs. In conclusion, the AIM2 inflammasome activation is increased in the SGECs of SS patients, and therefore should be considered an important pathogenic mediator of SS disease.

An overmodulation (OVM) technique is proposed based on Fourier analysis. The OVM trajectory is a mixture of 6 arc segments of the inscribed circle and 6 vertices of the voltage hexagon. By adjusting the dwell time at each vertex, the modulation index is determined. The fundamental component is expressed as a function of the dwell time, and the linearity with the modulation index is obtained by the inverse relation. This algorithm guarantees seamless transitions from the space vector PWM (SVPWM) to OVM and finally to the six-step. Apart from the VVVF control, the proposed algorithm works well with the interior permanent magnet synchronous motor (IPMSM) current controller. By computer simulation and experimental evidences, the effectiveness is demonstrated.

Total synthesis of d-fagomine and 6-deoxyfagomine from readily available d-lyxose is described. The key steps included regioselective and diastereoselective amination, hydroboration–oxidation, and Appel reaction. The reaction of 3,4-anti-tribenzyl ether with chlorosulfonyl isocyanate in toluene at 0 °C afforded 3,4-anti-amino alcohol, an essential compound for the preparation of d-fagomine and 6-deoxyfagomine, with a high diastereoselectivity (dr=26:1) in 74% yield. The origin of diastereoselectivity can be explained by the neighboring group effect, which leads to retention of the stereochemistry.

The stereoselective synthesis of (–)-α-conhydrine and its pyrrolidine analogue was achieved from readily available D-erythronolactone. The key step of this synthesis includes a highly regioselective and diastereoselective addition of chlorosulfonyl isocyanate to 1,2-anti-dibenzyl ether to afford the 1,2-anti-amino alcohol.

Small amounts of hydrogen-bonding comonomers such as N-(2-methacryloxyethyl)ethylene urea (MEEU) are often included in latex particle synthesis to promote adhesion of latex films to metals and old surfaces. Little is known about how these monomers affect the latex film formation process. Here we examine the influence of 1–7 wt.% MEEU on butyl acrylate-methyl methacrylate copolymer latex films using fluorescence resonance energy transfer (FRET) measurements, in conjunction with donor- and acceptor-labeled latex particles, to study the rates of polymer diffusion in these films. The presence of MEEU in the copolymer leads to small increases in the polymer glass transition temperature (Tg). It also tends to retard the rate of polymer diffusion. This effect, however, is very sensitive to the humidity of the surrounding atmosphere. It appears that moisture taken up in the film minimizes the influence of MEEU groups on the rate of polymer diffusion.

We propose that the non-equilibrium current measured in the $a-b$ plane of an underdoped cuprate (in either the strange metal or pseudogap regime) in contact with either an overdoped cuprate or a standard Fermi liquid can be used diagnose how different the pseudogap and strange metals are from a Fermi liquid. Naively one expects the strange metal to be more different from a Fermi liquid than is the pseudogap. We compute the expected non-equilibrium transport signal with the three Green functions that are available in the literature: 1) marginal Fermi liquid theory, 2) the phenomenological ansatz for the pseudogap regime and 3) the Wilsonian reduction of the Hubbard model which contains both the strange metal and pseudogap. All three give linear IV curves at low bias voltages. Significant deviations from linearity at higher voltages obtain only in the marginal Fermi liquid approach. The key finding, however, is that IV curves for the strange metal/Fermi liquid contact that exceed that of the pseudogap/Fermi liquid system. If this is borne out experimentally, this implies that the strange metal is less orthogonal to a Fermi liquid than is the pseudogap. Within the Wilsonian reduction of the Hubbard model, this result is explained in terms of a composite-particle picture. Namely, the pseudogap corresponds to a confinement transition of the charge degrees of freedom present in the strange metal. In the strange metal the composite excitations break up and electron quasiparticles scatter off bosons. The bosons here, however, do not arise from phonons but from the charge degrees of freedom responsible for dynamical spectral weight transfer., submitted to PRB

We study thermoelectric transport at low temperatures in correlated Kondo insulators, motivated by the recent observation of a high thermoelectric figure of merit(ZT) in $FeSb_2$ at $T \sim 10 K$. Even at room temperature, correlations have the potential to lead to high ZT, as in $YbAl_3$, one of the most widely used thermoelectric metals. At low temperature correlation effects are especially worthy of study because fixed band structures are unlikely to give rise to the very small energy gaps $E_g \sim 5 kT$ necessary for a weakly correlated material to function efficiently at low temperature. We explore the possibility of improving the thermoelectric properties of correlated Kondo insulators through tuning of crystal field and spin-orbit coupling and present a framework to design more efficient low-temperature thermoelectrics based on our results., Comment: 8 pages, 9 figures

We investigate the instabilities of the Mott-insulating phase of the weakly disordered Bose-Hubbard model within a renormalization group analysis of the replica field theory obtained by a strong-coupling expansion around the atomic limit. We identify a new order parameter and associated correlation length scale that is capable of capturing the transition from a state with zero compressibility, the Mott insulator, to one in which the compressibility is finite, the Bose glass. The order parameter is the relative variance of the disorder-induced mass distribution. In the Mott insulator, the relative variance renormalizes to zero, whereas it diverges in the Bose glass. The divergence of the relative variance signals the breakdown of self-averaging. The length scale governing the breakdown of self-averaging is the distance between rare regions. This length scale is finite in the Bose glass but diverges at the transition to the Mott insulator with an exponent of $\nu=1/D$ for incommensurate fillings. Likewise, the compressibility vanishes with an exponent of $\gamma=4/D-1$ at the transition. At commensurate fillings, the transition is controlled by a different fixed point at which both the disorder and interaction vertices are relevant., Comment: Extended, published version

Two remarkable features emerge from the exact Wilsonian procedure for integrating out the high-energy scale in the Hubbard model. At low energies, the number of excitations that couple minimally to the electromagnetic gauge is less than the conserved charge, thereby implying a breakdown of Fermi liquid theory. In addition, two charge $e$ excitations emerge in the lower band, the standard projected electron and a composite entity (comprised of a hole and a charge $2e$ bosonic field) which give rise to poles and zeros of the single-particle Green function, respectively. The poles generate spectral weight along an arc centered at $(\pi/2,\pi/2)$ while the zeros kill the spectral intensity on the back-side of the arc. The result is the Fermi arc structure intrinsic to cuprate phenomenology. The presence of composite excitations also produces a broad incoherent pseudogap feature at the $(\pi,0)$ region of the Brillouin zone, thereby providing a mechanism for the nodal/anti-nodal dichotomy seen in the cuprates., Comment: 8 pages, 4 figures: Extended version accepted to PRB. Additions include: 1) proof that the (\pi,\pi) solution is a global minimum, 2) extensive discussion of relation to SU(2) gauge theory of t-J model and 3) the meaning of the zero modes given the absence of Luttinger's theorem established in arXiv:1207.4201. New Published version

Hall and optical conductivity experiments on the cuprates indicate that the low-energy fermionic degrees of freedom in a doped Mott insulator posess a component that is dynamcially generated and hence determined by the temperature. We show explicitly how the spectrum in the lower Hubbard band should be partitioned to describe such dynamically generated charge degrees of freedom and corroborate this picture with the results from the exact low-energy theory of the Hubbard model. A consequence of such dynamics is that the Landau one-to-one correspondence between bare electrons and the effective fermionic degrees of freedom at low energies breaks down explicitly. This state of affairs obtains because the total hole number is not conserved as it contains a dynamical contribution. We propose that any experimental probe that couples to the low-energy dynamics of a doped Mott insulator, quantum oscillation experiments included, should be interpreted in terms of the total dynamically generated hole number rather than the bare value., Comment: 6 pages, 2 figures: Published version