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Auzinsh M Blushs K Ferber R Gahbauer F Jarmola A Tamanis M 《Physical review letters》2006,97(4):043002
We report the experimental observation of alignment to orientation conversion in the 7D3/2 and 9D3/2 states of Cs in the presence of an external dc electric field and without the influence of magnetic fields or atomic collisions. Initial alignment of angular momentum states was created by two-step excitation with linearly polarized laser radiation. The appearance of transverse orientation of angular momentum was confirmed by the observation of circularly polarized light. We present experimentally measured signals and compare them with the results of a detailed theoretical model based on the optical Bloch equations. The effect is odd under time reversal and should be taken into account in ever more sensitive searches for an electron electric dipole moment. 相似文献
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Andris Ozols Valdis Kokars Peteris Augustovs Ilze Uiska Kaspars Traskovskis Dmitry Saharov 《Central European Journal of Physics》2011,9(2):547-552
Light polarization effects on a holographic grating recording in a glassy chalcogenide a-As40S15Se45 film has been experimentally studied and compared with previously studied glassy molecular azobenzene film 8a at 633, using s − s,p − p, CE-1 and CE-2 circular-elliptic recording-beam polarizations (differing by light electric field rotation directions). The
azocompound exhibited much higher self-diffraction efficiency (SDE) and diffraction efficiency whereas chalcogenide was more
sensitive. Their recording efficiency polarization dependences also were different. SDE up to 45% was achieved in 8a with p − p and up to 2.6% in a-As40S15Se45 with CE-2 polarized recording beams. The polarization changes in the diffraction process were studied as well in these and
other materials (11, 16, 19 and a-As2S3 film, LiTaO3:Fe crystal). It was found that light polarization changes in the process of diffraction from gratings recorded vectorially
by s−p polarizations depended on chemical composition, wavelength, and exposure time. Vector gratings with SDE up to 25% were recorded
in 8a, rotating a linear polarization by 90°. No light polarization changes were found in azobenzene 19 and chalcogenide films and in LiTaO3:Fe crystal, thus showing a vector recording of scalar holograms. The recording mechanisms in azocompounds and chalcogenides
are discussed and compared. 相似文献
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NMR Spectroscopic Assignment of Backbone and Side‐Chain Protons in Fully Protonated Proteins: Microcrystals,Sedimented Assemblies,and Amyloid Fibrils
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Dr. Jan Stanek Dr. Loren B. Andreas Dr. Kristaps Jaudzems Dr. Diane Cala Dr. Daniela Lalli Andrea Bertarello Dr. Tobias Schubeis Dr. Inara Akopjana Dr. Svetlana Kotelovica Prof. Kaspars Tars Dr. Andrea Pica Dr. Serena Leone Prof. Delia Picone Dr. Zhi‐Qiang Xu Prof. Nicholas E. Dixon Dr. Denis Martinez Mélanie Berbon Nadia El Mammeri Dr. Abdelmajid Noubhani Dr. Sven Saupe Dr. Birgit Habenstein Dr. Antoine Loquet Dr. Guido Pintacuda 《Angewandte Chemie (International ed. in English)》2016,55(50):15504-15509
We demonstrate sensitive detection of alpha protons of fully protonated proteins by solid‐state NMR spectroscopy with 100–111 kHz magic‐angle spinning (MAS). The excellent resolution in the Cα‐Hα plane is demonstrated for 5 proteins, including microcrystals, a sedimented complex, a capsid and amyloid fibrils. A set of 3D spectra based on a Cα–Hα detection block was developed and applied for the sequence‐specific backbone and aliphatic side‐chain resonance assignment using only 500 μg of sample. These developments accelerate structural studies of biomolecular assemblies available in submilligram quantities without the need of protein deuteration. 相似文献
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Glutathione transferase (GST) A2-2 is the most efficient human enzyme in the biotransformation of the prodrug azathioprine (Aza). The activation of Aza has therapeutic potential for possible use of GSTs in targeted enzyme-prodrug treatment of diseases. Based on the assumed catalytic mechanism and computational docking of Aza to the active site of the enzyme, active-site residues were selected for construction of focused mutant libraries, which were thereafter screened for Aza activity. Mutants with elevated Aza activity were identified, DNA sequenced, and the proteins purified. The two most active mutants showed up to 70-fold higher catalytic efficiency than the parental GST A2-2. The structure of the most active triple mutant (L107G/L108D/F222H) enzyme was determined by X-ray crystallography demonstrating significant changes in the topography of the active site facilitating productive binding of Aza as a substrate. 相似文献
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Intermolecular Charge-Transfer Luminescence by Self-Assembly of Pyridinium Luminophores in Solutions
Designing a luminophore for application both in solution and in the solid state is a highly challenging task given the distinct nature of intermolecular interactions in these phases. In this context, we demonstrate that self-assembly of non-emissive charged pyridinium luminophores enables luminescence in solutions through a mechanism that is characteristic for the crystal state. Specifically, protonation of pyridine luminophore subunits in a solution promotes oligomer formation through intermolecular π+-π interactions, leading to an intermolecular charge-transfer type luminescence. The luminescence turn-on by protonation is utilized for a highly efficient solution-state luminescent sensing of hydrogen chloride and sulfonic acids (TfOH, TsOH and MsOH) with detection limits spanning the range from 0.06 to 0.33 ppm. The protonation followed by self-assembly results in a bathochromic shift of the emission from 420 nm to 550 nm. 相似文献
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Jan Stanek Loren B. Andreas Kristaps Jaudzems Diane Cala Daniela Lalli Andrea Bertarello Tobias Schubeis Inara Akopjana Svetlana Kotelovica Kaspars Tars Andrea Pica Serena Leone Delia Picone Zhi‐Qiang Xu Nicholas E. Dixon Denis Martinez Mlanie Berbon Nadia El Mammeri Abdelmajid Noubhani Sven Saupe Birgit Habenstein Antoine Loquet Guido Pintacuda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(50):15730-15735
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Frontispiece: NMR Spectroscopic Assignment of Backbone and Side‐Chain Protons in Fully Protonated Proteins: Microcrystals,Sedimented Assemblies,and Amyloid Fibrils
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Dr. Jan Stanek Dr. Loren B. Andreas Dr. Kristaps Jaudzems Dr. Diane Cala Dr. Daniela Lalli Andrea Bertarello Dr. Tobias Schubeis Dr. Inara Akopjana Dr. Svetlana Kotelovica Prof. Kaspars Tars Dr. Andrea Pica Dr. Serena Leone Prof. Delia Picone Dr. Zhi‐Qiang Xu Prof. Nicholas E. Dixon Dr. Denis Martinez Mélanie Berbon Nadia El Mammeri Dr. Abdelmajid Noubhani Dr. Sven Saupe Dr. Birgit Habenstein Dr. Antoine Loquet Dr. Guido Pintacuda 《Angewandte Chemie (International ed. in English)》2016,55(50)
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