The methyl group as phosphate protecting group in nucleotide syntheses

A novel method is described for the removal of a methyl protecting group from phosphotriesters in oligonucleotides.     

Study on Angelica and its different extracts by Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy

In order to develop a rapid and effective analysis method for studying integrally the main constituents in the medicinal materials and their extracts, discriminating the extracts from different extraction process, comparing the categories of chemical constituents in the different extracts and monitoring the qualities of medicinal materials, we applied Fourier transform infrared spectroscopy (FT-IR) associated with second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy (2D-IR) to study the main constituents in traditional Chinese medicine Angelica and its different extracts (extracted by petroleum ether, ethanol and water in turn). The findings indicated that FT-IR spectrum can provide many holistic variation rules of chemical constituents. Use of the macroscopical fingerprint characters of FT-IR and 2D-IR spectrum can not only identify the main chemical constituents in medicinal materials and their different extracts, but also compare the components differences among the similar samples. This analytical method is highly rapid, effective, visual and accurate for pharmaceutical research.     

Measuring energy differences by BEC interferometry on a chip

We investigate the use of a Bose-Einstein condensate trapped on an atom chip for making interferometric measurements of small energy differences. We measure and explain the noise in the energy difference of the split condensates, which derives from statistical noise in the number difference. We also consider systematic errors. A leading effect is the variation of the rf magnetic field in the trap with distance from the wires on the chip surface. This can produce energy differences that are comparable with those due to gravity.     

Numerical solutions to 2D Maxwell–Bloch equations

Rare-earth-doped crystals contain inhomogeneously broadened two-level atoms. Optical propagation and nonlinear interaction in the crystals can be described by the Maxwell–Bloch equations. We show a consistent numerical approach that solves Maxwell’s equations by using the FFT-finite difference beam propagation method and the Bloch equations by using the finite difference method. Numerical simulation results are given for an off-axis 3-pulse photon echo.     

Synthesis and application of a recyclable ionic liquid-supported imidazolidinone catalyst in enantioselective 1,3-dipolar cycloaddition

The synthesis of recyclable ionic liquid-supported imidazolidinone catalyst I and its application in 1,3-dipolar cycloaddition of nitrone with α,β-unsaturated aldehyde with high performance were described. Most importantly, the catalyst I can be recovered and recycled for up to five runs without observing significant decrease in catalytic activity.     

Ionic rectification by electrostatically actuated tethers on single walled carbon nanotube membranes

Large electrostatically actuating charged tethers (~2.5 nm) at the tip entrances of single walled carbon nanotubes (i.d. ~ 1.5 nm) can dramatically enhance ionic gating at the CNT core entrance. Significant rectification of small ions at physiological ionic strengths is observed and this system closely mimics the function of protein channels.     

Longitudinal analysis of novel Alzheimer's disease proteomic cerebrospinal fluid biomarkers during intravenous immunoglobulin therapy

Intravenous immunoglobulin (IVIg) therapy has shown promising results in treating Alzheimer's disease (AD). In this study, a Random Forest (RF) classification model was used to identify possible effects of IVIg on a group of eight subjects who underwent immunotherapy. Cerebrospinal fluid (CSF) samples from eight AD subjects who underwent IVIg therapy were collected before therapy, after 6 months of therapy, and after a 3-month drug washout period. Samples were analyzed using 2DE and further studied using a RF classification model to identify effects of IVIg on a panel of 23 putative diagnostic AD biomarkers previously identified. Six of the eight subjects showed improvements with respect to the 23 AD diagnostic biomarkers after 6 months of therapy compared to the samples taken at the outset of the trial. All subjects reverted back to baseline during drug washout. These results are also consistent with clinical observations. The observed improvements in subjects during 6 months of IVIg therapy and the reversion back to baseline during drug washout provides preliminary evidence regarding the potential use of IVIg as an AD immunotherapy.