In this paper, a compact model of nonquasi-static (NQS) carrier-transport effects in MOSFETs is reported, which takes into account the carrier-response delay to form the channel. The NQS model, as ...implemented in the surface-potential-based MOSFET Hiroshima University STARC IGFET model, is verified to predict the correct transient terminal currents and to achieve a stable circuit simulation. Simulation results show that the NQS model can even reduce the circuit simulation time in some cases due to the elimination of unphysical overshoot peaks normally calculated by a QS-model. An average additional computational cost of only 3% is demonstrated for common test circuits. Furthermore, harmonic distortion characteristics are investigated using the developed NQS model. While the distortion characteristics at low drain bias and low switching frequency are determined mainly by carrier mobility, distortion characteristics at high frequency are found to be strongly influenced by channel charging/discharging
The low-energy quasiparticle structures in the vicinity of the specular surface of the superfluid
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He-B are theoretically investigated, based on the Bogoliubov-de Gennes (BdG) framework. A ...non-trivial topological invariant in the bulk of
3
He-B ensures the existence of surface Andreev bound states, called the edge states. The anisotropic spin dynamics arising from the self-Hermitian property of the topologically protected edge states is studied in detail based on the numerical diagonalization of the BdG equation, where the effect of the pair creation and annihilation is underlined. We also propose an experimental way to detect the low-lying spectra of the edge modes through the power law behavior of the low-temperature surface specific heat.
Here, we report the identification and characterization of a novel tyrosine phosphorylation site in the carboxy-terminal Src Homology 3 (SH3) (SH3C) domain of the Crk adaptor protein. Y251 is located ...in the highly conserved RT loop structure of the SH3C, a region of Crk involved in the allosteric regulation of the Abl kinase. Exploiting kinase assays to show that Y251 is phosphorylated by Abl in vitro, we generated affinity-purified antisera against phosphorylated Y251 in Crk and showed that Abl induces phosphorylation at Y251 in vivo, and that the kinetics of phosphorylation at Y251 and the negative regulatory Y221 site in vitro are similar. Y251 on endogenous Crk was robustly phosphorylated in chronic myelogenous leukemia cell lines and in A431 and MDA-MB-468 cells stimulated with epidermal growth factor. Using streptavidin-biotin pull downs and unbiased high-throughput Src Homology 2 (SH2) profiling approaches, we found that a pY251 phosphopeptide binds specifically to a subset of SH2 domains, including Abl and Arg SH2, and that binding of pY251 to Abl SH2 induces transactivation of Abl 1b. Finally, the Y251F Crk mutant significantly abrogates Abl transactivation in vitro and in vivo. These studies point to a yet unrealized positive regulatory role resulting from tyrosine phosphorylation of Crk, and identify a novel mechanism by which an adaptor protein activates a non-receptor tyrosine kinase by SH2 domain displacement.
The phenanthroline adduct of the tris(2-thenoyltrifluoroaceto-O,O‘)europium(III) complex, Eu(TTA)3phen, was doped into organically modified silicate (ORMOSIL) matrixes via the sol−gel process, and ...the luminescence properties of the resultant ORMOSIL composite phosphors (ORMOSIL:Eu(TTA)3phen) were characterized. The emission intensity of the composite phosphors maximized at ∼50% vs the commercially available lamp phosphor Y(P,V)O4:Eu, and transparent ORMOSIL:Eu(TTA)3phen composite phosphor disks (45 mm in diameter by 1.5 mm) were obtained under appropriate complex concentration and matrix composition. Moreover, the emission intensity of the composite phosphors was found to be maintained at the same level even after standing for up to 180 days in air, but lowered after heat treatments (100−300 °C), possibly due to the transformation of the β-diketonate ligand from the photoactive π electron-conjugated enolate to the corresponding nonphotoactive ketone form. In particular, the ORMOSIL:Eu(TTA)3phen composite phosphor powders treated with (CH3)3SiNHSi(CH3)3 (hexamethyldisilazane, HMDS) showed a remarkable increase in emission intensity, owing to the improved water repellency resulting from the implantation of the −OSi(CH3)3 (trimethylsilyl substituent: TMS) in the ORMOSIL composites and the favorable reconversion of the ligand from the nonconjugated β-diketone to the photoactive conjugated enolate form as induced by the NH3 evolved during the TMS modification process. A composite phosphor with high emission intensity (∼70% vs Y(P,V)O4:Eu) was obtained after the modification.
In chiral p-wave superconductors a flux lattice of doubly quantized vortices is shown to be energetically stable for fields Hc1 < HFL < H < Hc2, while at low fields a lattice of singly quantized ...vortices is stable. Here we report self-consistent calculations by Eilenberger theory for spatial structures of the pair potential and current density for vortex states of single- and double-winding vortices in chiral p-wave superconductors with a cylindrical Fermi surface.
The complete low-energy collective-excitation spectrum of vortex lattices is discussed for rotating Bose-Einstein condensates by solving the Bogoliubov-de Gennes equation, yielding, e.g., the ...Tkachenko mode recently observed at JILA. The totally symmetric subset of these modes includes the transverse shear, common longitudinal, and differential longitudinal modes. We also solve the time-dependent Gross-Pitaevskii equation to simulate the actual JILA experiment, obtaining the Tkachenko mode and identifying a pair of breathing modes. Combining both approaches allows one to unambiguously identify every observed mode.
Prokineticin 2 (PK2) is a putative output molecule from the SCN. PK2 RNA levels are rhythmic in the mouse SCN, with high levels during the day, and PK2 administration suppresses nocturnal locomotor ...activity in rats. The authors examined the PK2 system in a diurnal rodent, Arvicanthis niloticus, to determine whether PK2 or PK2 receptors differ between diurnal and nocturnal species. The major transcript variant of A. niloticus PK2 (AnPK2) encodes a 26-residue signal peptide followed by the presumed mature peptide of 81 residues. Within the grass rat signal sequence, polymorphic sequences and amino acid substitutions were observed relative to mouse and laboratory rats, but the hydrophobic core and cleavage site of the signal sequence were preserved. The mature PK2 peptide is identical among A. niloticus, rat, and mouse. AnPK2 mRNA is rhythmically expressed in the SCN, with peak RNAlevels occurring in the morning, preceding peaks of Per1 and Per2 as in mouse SCN. Analysis of prokineticin receptor 2 (PKR2) sequences revealed polymorphisms among the grass rats studied. PKR2 mRNAwas expressed in the SCN and paraventricular nuclei of the thalamus and hypothalamus. While further analysis is necessary, there is no clear evidence indicating that a difference in the PK2 ligand/receptor system accounts for diurnality in this rodent species. These data contribute to a growing body of evidence suggesting that the key to diurnality lies downstream of the SCN in A. niloticus.
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