Single hole motion in LaMnO3_3

We study single hole motion in LaMnO$_3$ using the classical approximation for JT lattice distortions, a modified Lang-Firsov approximation for dynamical breathing-mode phonons, and the self-consistent Born approximation (verified by exact diagonalization) for hole-orbital-excitation scattering. We show that in the realistic parameter space for LaMnO$_3$, quantum effects of electron-phonon interaction are small. The quasiparticle bandwidth $W \simeq 2.2J$ in the purely orbital t-J model. It is strikingly broadened to be of order $t$ by strong static Jahn-Teller lattice distortions even when the polaronic band narrowing is taken into account.Comment: 4 pages, 4 eps figure

The role of domain E in the activity of Bacillus macerans cyclodextrin glucanotransferase

Cyclodextrin glucanotransferase (CGT) folds into five domains A, B, C, D and E. Domain E has the ability to bind starch and cyclodextrins (CDs) and is considered the starch-binding domain of CGT. The role of domain E in the catalysis of Bacillus macerans cyclodextrin glucanotransferase was investigated by constructing five CGT mutants. The truncated CGT (CGT[delta]E) mutant was constructed by deleting domain E, and the chimeric CGT (CGT-SBD) by replacing domain E with the starch-binding domain (SBD) of Aspergillus glucoamylase I. The modified CGT (CGT+6) was constructed by inserting a six-amino-acid pseudo linker between domains D and E. The Tyr634 residue in the maltose binding site in Domain E (MBS2) was replaced with a glycine and phenylalanine residue, respectively, to produce the Y634G and Y634F mutants;CGT[delta]E exhibited no detectable activity, whereas CGT-SBD had very low cyclization, starch-degrading, and coupling activities. CGT+6 exhibited about 50-60% of the wild-type CGT (WT-CGT) activity, and its thermostability was lower than that of WT-CGT. The Km value of the cyclization activity of CGT+6 was about 2.6 fold greater than that of WT-CGT. The overall properties of the Y634F mutant were similar to that of WT-CGT. The thermostability of the Y634G mutant was significantly lower than that of WT-CGT, Y634F, and CGT+6. The starch substrate provided little stabilization to Y634G indicating that the aromatic side chains of Tyr634 or Phe634 participated in binding soluble starch. The Km value of the cyclization reaction with Y634G was about 1.4 times greater than that of WT-CGT. The results of this study suggest that domain E cooperates with the catalytic domain in binding long substrates. The groove, extending from the active site to domain E, can be considered as an extension of the active site cleft which assists in the binding and/or directing the binding of long substrates in the active site. The optimal orientation and distance of domain E from the catalytic domain appears important for maintaining the integrity of the groove structure

Design of Compact Planar Diplexer Based on Novel Spiral-Based Resonators

A miniaturized planar diplexer utilizing the novel spiral-based resonators is proposed. The given cell which is initially proposed in this article is composed of two separated rectangular spirals which are asymmetrical to each other and thus, it is called as ‘asymmetrical separated spirals resonator’ (ASSR). ASSR has more superior transmission property than the previous prototype and extremely compact dimension is also achieved. It is demonstrated that ASSR can exhibit bandpass performance with high frequency selectivity and good transmission property within the relatively low frequency band. Based on the given characteristic, one planar diplexer composed of T-junction and two ASSRs is synthesized and the fabricated prototype with compact dimension is achieved, thanks to ASSRs explored. Simultaneously, the transversal dimension of each channel is extremely compact because ASSRs are completely embedded in the feed lines. Both the simulated and measured results indicate that satisfactory impedance matching and high isolation between two channels are achieved. Furthermore, the proposed diplexer is uniplanar and no defected ground structure is introduced