The mobility of protonated aminoalcohols: Evidence for proton-induced cyclization

The reduced mobility in air, at 200C, of protonated aminoalcohols was measured by ion mobility spectrometry (IMS). The relatively high mobilities that were measured indicated that proton-induced cyclization took place in the aminoalcohols, similar to what was previously observed in diamines. This conclusion is in agreement with the proton affinities (PA) of these compounds that indicated that the proton was more strongly attached to the molecule than in normal aliphatic amines. It was also found that the, = aminoalcohols had slightly higher mobilities than their corresponding 1,2 isomers, further supporting the conclusion for proton-induced cyclization.     

Mono- and binuclear ruthenium corroles: synthesis,spectroscopy, electrochemistry,and structural characterization

The aim of this research was to prepare mononuclear ruthenium corroles, because of the well-documented potency of analogous porphyrin complexes in catalysis. The syntheses of the mononuclear nitrosyl complexes [Ru(tpfc)(NO)] and [Ru(tdcc)(NO)] (tpfc=trianion of 5,10,15-tris(pentafluorophenyl)corrole, tdcc=trianion of 5,10,15-tris(2,6-dichlorophenyl)corrole), and of the binuclear [[Ru(tpfc)](2)] were achieved by using [[Ru(cod)Cl(2)](x)] (cod=cyclooctadiene) as the metal source. The NMR spectra of all three complexes clearly demonstrate that they are diamagnetic; this is consistent with a triple bond between the metal ions in [[Ru(tpfc)](2)] and is expected for classical [MNO](6) complexes. These features were further substantiated by the stretching frequencies of the [MNO] moieties, electrochemical measurements on all complexes, and the X-ray crystal structures of [Ru(tpfc)(NO)] and [[Ru(tpfc)](2)]. A comparison of the spectroscopic and structural characteristics of these new complexes with analogous iron corroles, as well as with iron and ruthenium porphyrins, suggests that it will be hard to obtain mononuclear ruthenium corroles without pi-accepting ligands.     

Laser-based double beam absorption detection for aggregation immunoassays using gold nanoparticles

A laser-based double beam absorption detection system for aggregation immunoassays has been developed. The assay was based on the aggregation of gold nanoparticles that are coated with protein antigens in the presence of their corresponding antibodies. The aggregation of the gold nanoparticles results in an absorption change that is monitored at 635 nm using the double beam spectrometer. The noise level of the spectrometer is 1x10(-6)arbitrary units. This corresponds to a tenfold improvement in comparison to commercial absorption detectors and is comparable with previously reported more complicated laser-based absorption spectrometers. The dye Nile-Blue-A was used to test the analytical performance of the system. A limit of detection of 3x10(-8 )M Nile-Blue-A was observed. The relative standard deviation between consecutive measurements was lower than 1.5%. The system is suitable for field applications of aggregation-based immunoassays.     

GENERAL PURPOSE LAMPS INDUCE POLYOMA DNA REPLICATION IN H3 CELLS

Abstract— We have previously demonstrated the ability of UVC (254 nm) radiation to induce asynchronous polyoma replication in rat fibroblast cells (H3 line) that contain an integrated copy of polyoma virus. In the present study we show that general purpose lamps can induce polyoma replication in these cells as well. The amount of UV radiation emitted by three different light sources was determined and the effects of each source on the replication of polyoma DNA was assessed. Our findings indicate that a 100 W incandescent lamp had a minimal effect on replication, whereas a 90 s exposure to a halogen lamp or a 160 W mercury vapor lamp induced replication 1.5-fold and 2-fold, respectively, in comparison with nontreated controls. We have previously shown that asynchronous polyoma replication in H3 cells involves UV-inducible cellular protein factors. Our present results indicate that these factors are also activated by exposure to commonly used lamps that emit comparable doses of UV radiation.     

The mobility and ion structure of protonated aminoazoles

The reduced mobility of protonated pyrazole derivatives was measured by ion mobility spectrometry (IMS) in air, nitrogen, and carbon dioxide, at temperatures between 150 and 250°C. It was found that the mobility of protonated 5-amino-1-phenylpyrazole was higher than that of its 3- and 4-isomers. This was attributed to the fact that in the 5-isomer the preferred site of protonation is on the endocyclic nitrogen, which leads to delocalization of the ionic charge, and thus to a diminished interaction with the drift gas molecules. On the other hand, protonated 5-amino-1-methylpyrazole has a slightly lower mobility than its isomers, which is indicative of a different protonation mechanism.     

Platinum determination by instrumental neutron activation analysis with special reference to the spectral interference of Sc-47 on the platinum indicator nuclide Au-199

A method of instrumental neutron activation analysis (INAA) is developed for the determination of platinum by the ¹⁹⁹Au daughter of ¹⁹⁹Pt in the presence of the spectral interference from the ⁴⁷Sc daughter of ⁴⁷Ca. The contributions of the Pt and Ca signals to the integral 157–161 keV peak were separated by calculating the number of disintegrations due to the ⁴⁷Sc from the signal of her parent ⁴⁷Ca at 1297.1 keV γ-ray. The method was used to calculate the trace concentrations of Pt in air samples, collected on filters.     

Tight lower bounds for linear 2-query LCCs over finite fields

A Locally Correctable Code (LCC) is an error correcting code that has a probabilistic self-correcting algorithm that, with high probability, can correct any coordinate of the codeword by looking at only a few other coordinates, even if a δ fraction of the coordinates is corrupted. LCCs are a stronger form of LDCs (Locally Decodable Codes) which have received a lot of attention recently due to their many applications and surprising constructions.In this work, we show a separation between linear 2-query LDCs and LCCs over finite fields of prime order. Specifically, we prove a lower bound of the form p ^Ω(δd) on the length of linear 2-query LCCs over F _p , that encode messages of length d. Our bound improves over the known bound of 2 ^Ω(δd) [8,10,6] which is tight for LDCs. Our proof makes use of tools from additive combinatorics which have played an important role in several recent results in theoretical computer science.We also obtain, as corollaries of our main theorem, new results in incidence geometry over finite fields. The first is an improvement to the Sylvester-Gallai theorem over finite fields [14] and the second is a new analog of Beck's theorem over finite fields.The paper also contains an appendix, written by Sergey Yekhanin, showing that there do exist nonlinear LCCs of size 2 ^O(d) over F _p , thus highlighting the importance of the linearity assumption for our result.