Modifying infrared scattering effects of single yeast cells with plasmonic metal mesh

The scattering effects in the infrared (IR) spectra of single, isolated bread yeast cells (Saccharomyces cerevisiae) on a ZnSe substrate and in metal microchannels have been probed by Fourier transform infrared imaging microspectroscopy. Absolute extinction [(3.4±0.6)×10(-7) cm(2) at 3178 cm(-1)], scattering, and absorption cross sections for a single yeast cell and a vibrational absorption spectrum have been determined by comparing it to the scattering properties of single, isolated, latex microspheres (polystyrene, 5.0 μm in diameter) on ZnSe, which are well modeled by the Mie scattering theory. Single yeast cells were then placed into the holes of the IR plasmonic mesh, i.e., metal films with arrays of subwavelength holes, yielding "scatter-free" IR absorption spectra, which have undistorted vibrational lineshapes and a rising generic IR absorption baseline. Absolute extinction, scattering, and absorption spectral profiles were determined for a single, ellipsoidal yeast cell to characterize the interplay of these effects.     

Antideuteron yield at the AGS and coalescence implications

We present Experiment 864's measurement of invariant antideuteron yields in 11.5A GeV/c Au+Pt collisions. The analysis includes 250x10(6) triggers representing 14x10(9) 10% central interactions sampled for events with high mass candidates. We find (1/2pip(t))d(2)N/dydp(t) = 3.5+/-1.5(stat)+0.9-0.5(syst)x10(-8) GeV-2 c(2) for 1.8 = 0.35 GeV/c ( y(c.m.) = 1.6) and 3.7+/-2.7(stat)+1.4-1.5(syst)x10(-8) GeV-2 c(2) for 1.4 = 0.26 GeV/c, and a coalescence parameter B2; of 4.1+/-2. 9(stat)+2.3-2.4(syst)x10(-3) GeV2 c(-3). Implications for coalescence and antimatter annihilation are discussed.     

The stabilisation of final focus system

The StaFF (stabilisation of final focus) system will use interferometers to monitor the relative positions and orientations of several key components in the beamdelivery and interaction region. Monitoring the relative positions of the ILC final focus quadrupole magnets will be the most demanding application, where mutual and beam-relative stability will have a direct impact on machine luminosity. Established, laser-based frequency scanning interferometry (FSI) and fixed-frequency interferometry (FFI) offer positional resolution at length scales of the laser wavelength (1500 nm to 1560 nm) and a thousandth of the wavelength, respectively. As part of the ATF at KEK, StaFF will use interferometers to measure lines of a geodetic network to record relative motion between two beam position monitors. Interferometers are being designed and tested in Oxford prior to deployment at the ATF.      

trans‐4‐[(4‐Di­methyl­amino­phenyl)­imino­methyl]‐N‐methyl­pyridinium para‐toluene­sulfonate

In the title compound, C₁₅H₁₈N₃⁺·C₇H₇O₃S^?, the phenyl­ene and pyridyl rings are somewhat twisted with respect to each other, forming a dihedral angle of 23.49 (6)°. The compound contains a dipolar chromophoric cation, but crystallizes in the centrosymmetric space group P2₁/n and is thus not expected to display quadratic non‐linear optical effects.     

High‐Throughput Ligand Screening Enables the Enantioselective Conjugate Borylation of Cyclobutenones to Access Synthetically Versatile Tertiary Cyclobutylboronates

Cyclobutane rings are important in medicinal chemistry, yet few enantioselective methods exist to access this scaffold. In particular, cyclobutylboronates are receiving increasing attention in the literature due to the synthetic versatility of alkylboronic esters and the increasing role of boronic acids in drug discovery. Herein, a conjugate borylation of α‐alkyl,β‐aryl/alkyl cyclobutenones is reported leading to the first synthesis of enantioenriched tertiary cyclobutylboronates. Cyclobutanones with two stereogenic centers are obtained in good to high yield, with high enantioselectivity and diastereoselectivity. Vital to this advance are the development of a novel approach to α,β unsymmetrically disubstituted cyclobutenone substrates and the use of a high‐throughput chiral ligand screening platform. The synthetic utility of both the boronic ester and ketone functionalities is displayed, with remarkable chemoselectivity for either group being possible in this small ring scaffold.     

Recent Advances in Visible Light-Mediated Radical Fluoro-alkylation, -alkoxylation, -alkylthiolation, -alkylselenolation,and -alkylamination

In the last few years, many reagents and protocols have been developed to allow for the efficient fluorofunctionalization of a diverse set of scaffolds ranging from alkanes, alkenes, alkynes, and (hetero)arenes. The concomitant rise of organofluorine chemistry and visible light-mediated synthesis have synergistically expanded the fields and have mutually benefitted from developments in both fields. In this context, visible light driven formations of radicals containing fluorine have been a major focus for the discovery of new bioactive compounds. This review details the recent advances and progress made in visible light-mediated fluoroalkylation and heteroatom centered radical generation.     

Anodic acetamidoselenation of alkenes

Anodic oxidation of diphenyldiselenide in acetonitrile in the presence of an alkene gives acetamidoselenides.     

Highly fluorinated heterocycles part XV [1]. The metal catalysed defluorinative rearrangement of polyfluorinated pyrrolidines to polyfluoropyridines

Pyrolysis of a number of polyfluoro-1-alkyl pyrrolidines over iron gauze at 500–525° affords a small conversion to polyfluoropyridines.     

Why hyperpolarizabilities fall short of the fundamental quantum limits

Quantum sum rules impose limits on the hyperpolarizability, beta. A survey of the largest second-order molecular susceptibilities finds what appears to be a universal gap between the experimental results and the fundamental limits. In this work, we use theory, linear spectroscopy, Raman spectroscopy, and measured values of beta (using hyper-Rayleigh scattering and Stark Spectroscopy) to show that this gap is due to an unfavorable arrangement of excited state energies. The question of whether this result is a universal property of a quantum system or a matter of present paradigms for making molecules is discussed.