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131.
Ravi Pant David Marpaung Irina V. Kabakova Blair Morrison Christopher G. Poulton Benjamin J. Eggleton 《Laser \u0026amp; Photonics Reviews》2014,8(5):653-666
Demonstration of continuously tunable delay, low‐noise lasers, dynamically controlled gratings, and optical phase shifting using the stimulated Brillouin scattering (SBS) process has lead to the emergence of SBS as a promising technology for microwave photonics. On‐chip realization of SBS enables photonic integration of microwave photonic signal processing and offers significantly enhanced performance and improved efficiency. On‐chip stimulated Brillouin scattering is reviewed in the context of slow‐light based tunable delay, low‐noise narrow linewidth lasers and filtering for integrated microwave photonics. A discussion on key material and device properties, necessary to enable on‐chip Brillouin scattering using both the single‐pass and resonator geometry, is presented along with an outlook for photonic integration of microwave signal processing and generation in other platforms. 相似文献
132.
We prove that a complex (κ, μ)-space with κ < 1 is a locally homogeneous complex contact metric manifold. Also, a complex (κ, μ)-space has either κ = 1 or is GH-locally symmetric. 相似文献
133.
Baillie SE Blair VL Blakemore DC Hay D Kennedy AR Pryde DC Hevia E 《Chemical communications (Cambridge, England)》2012,48(14):1985-1987
Comparing the reactivity of the related lithium zincates [(THF)LiZn(TMP)(t)Bu(2)] (1) and [(PMDETA)LiZn(t)Bu(3)] (2) towards pyrazine discloses two new bimetallic approaches for the selective 2,5-dideprotonation and room temperature C-H alkylation of this sensitive heterocycle. 相似文献
134.
Catherine J. Fletcher Daniel J. Blair Katherine M.P. Wheelhouse Varinder K. Aggarwal 《Tetrahedron》2012,68(37):7598-7604
A concise, highly enantioselective synthesis of sesquiterpene natural products (?)-debromoaplysin and (?)-aplysin has been completed. The key steps included lithiation–borylation of a secondary benzylic carbamate to give a tertiary boronic ester followed by propenylation which installed the quaternary stereocenter with complete enantioselectivity. Subsequent RCM followed by deprotection and in situ cyclization led to debromoaplysin with good diastereoselectivity from which the target compound was prepared in just eight overall steps. 相似文献
135.
Filippo Favretto Jeremy D. Baker Timo Strohker Loren B. Andreas Laura J. Blair Stefan Becker Markus Zweckstetter 《Angewandte Chemie (International ed. in English)》2020,59(14):5643-5646
Peptidylprolyl isomerases (PPIases) catalyze cis/trans isomerization of prolines. The PPIase CypA colocalizes with the Parkinson's disease (PD)‐associated protein α‐synuclein in cells and interacts with α‐synuclein oligomers. Herein, we describe atomic insights into the molecular details of the α‐synuclein/CypA interaction. NMR spectroscopy shows that CypA catalyzes isomerization of proline 128 in the C‐terminal domain of α‐synuclein. Strikingly, we reveal a second CypA‐binding site formed by the hydrophobic sequence 47GVVHGVATVA56, termed PreNAC. The 1.38 Å crystal structure of the CypA/PreNAC complex displays a contact between alanine 53 of α‐synuclein and glutamine 111 in the catalytic pocket of CypA. Mutation of alanine 53 to glutamate, as found in patients with early‐onset PD, weakens the interaction of α‐synuclein with CypA. Our study provides high‐resolution insights into the structure of the PD‐associated protein α‐synuclein in complex with the most abundant cellular cyclophilin. 相似文献
136.
Dr. Samantha A. Orr Dr. John A. Kelly Aaron J. Boutland Dr. Victoria L. Blair 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4947-4951
This study details the isolation and characterisation of three novel silver(I) amides in solution and solid-state, [Ag(Cy3P)(HMDS)] 2 , [Ag(Cy3P){N(TMS)(Dipp)}] 3 and [Ag(Cy3P)2(NPh2)] 4 . Their catalytic abilities have proved successful in hydroboration and hydrosilylation reactions with a full investigation performed with complex 2 . Both protocols proceed under mild conditions, displaying exceptional functional-group tolerance and chemoselectivity, in excellent conversions at competitive reaction times. This work reveals the first catalytic hydroboration of aldehydes and ketones performed by a silver(I) catalyst. 相似文献
137.
Commercially available chiral columns were unable to provide adequate resolution of enantiomers of the antiarrhythmic drug encainide or its major metabolites. The homochiral derivatizing agent, (-)-menthyl chloroformate, was found to react at the tertiary piperidine nitrogen of racemic encainide providing two menthyl carbamate diastereomers. The individual diastereomers could be separated with baseline resolution on normal-phase high-performance liquid chromatography on a silica column. Structures of the derivatives were confirmed by electron impact mass spectrometry and 1H NMR spectroscopy. The method was adapted for the chiral analysis of the major metabolites of encainide. The limit of sensitivity for racemic encainide was 10 ng on column and it was possible to detect a mixture containing (+)- and (-)-encainide in a ratio of 1:99. Preliminary studies indicated that (-)-encainide was O-demethylated to a greater extent than the (+)-enantiomer by rat liver microsomes. 相似文献
138.
A sphere of dimension 4n+3 admits three Sasakian structures and it is natural to ask if a submanifold can be an integral submanifold for more than one of the contact structures. In the 7-sphere it is possible to have curves which are Legendre curves for all three contact structures and there are 2 and 3-dimensional submanifolds which are integral submanifolds of two of the contact structures. One of the results here is that if a 3-dimensional submanifold is an integral submanifold of one of the Sasakian structures and invariant with respect to another, it is an integral submanifold of the remaining structure and is a principal circle bundle over a holmophic Legendre curve in complex projective 3-space. 相似文献
139.
An asymptotic formula is given for the number of integers n≤x for which φ(n) is not divisible by a given odd prime. 相似文献
140.
Charles Blair 《Annals of Operations Research》1992,34(1):13-19
We show that (L+1)-level linear programs are as difficult as levelL of the polynomial-time hierarchy, even if one only considers problems with unique optimal solutions.Dedicated to Robert Jeroslow (1942–1988) 相似文献