Asymmetric Total Synthesis of Stagonolide G

A simple asymmetric total synthesis of stagonolide G ( 1 ) is described. Asymmetric dihydroxylation, regioselective epoxide ring opening, and vinyl Grignard reactions are involved in generating the stereogenic centers C(4) and C(8), followed by Grubbs‐II‐catalyzed ring‐closing metathesis (RCM).     

Synthesis and linear and nonlinear absorption properties of dendronised ruthenium(II) phthalocyanine and naphthalocyanine

Ruthenium phthalocyanines and naphthalocyanines with axial dendronised pyridine ligands show high solubility in a variety of solvents, and exhibit solid-state absorption spectra that are comparable to those obtained in dilute solution, making them interesting candidates for optical limiting in the visible.     

Refining comparative proteomics by spectral counting to account for shared peptides and multiple search engines

Spectral counting has become a widely used approach for measuring and comparing protein abundance in label-free shotgun proteomics. However, when analyzing complex samples, the ambiguity of matching between peptides and proteins greatly affects the assessment of peptide and protein inventories, differentiation, and quantification. Meanwhile, the configuration of database searching algorithms that assign peptides to MS/MS spectra may produce different results in comparative proteomic analysis. Here, we present three strategies to improve comparative proteomics through spectral counting. We show that comparing spectral counts for peptide groups rather than for protein groups forestalls problems introduced by shared peptides. We demonstrate the advantage and flexibility of this new method in two datasets. We present four models to combine four popular search engines that lead to significant gains in spectral counting differentiation. Among these models, we demonstrate a powerful vote counting model that scales well for multiple search engines. We also show that semi-tryptic searching outperforms tryptic searching for comparative proteomics. Overall, these techniques considerably improve protein differentiation on the basis of spectral count tables.     

Live cell refractometry using microfluidic devices

Using Hilbert phase microscopy for extracting quantitative phase images, we measured the average refractive index associated with live cells in culture. To decouple the contributions to the phase signal from the cell refractive index and thickness, we confined the cells in microchannels. The results are confirmed by comparison with measurements of spherical cells in suspension.     

Stuffing improves the stability of fullerenelike boron clusters

First-principles electronic structure calculations show that boron clusters B98, B99, B100, B101, and B102 based on icosahedral-B12 stuffed fullerenes are more stable than the fullerenelike boron clusters. These more stable structures are envisaged as an icosahedral B12 each vertex of which is connected to the apex of a pentagonal pyramid (B6) via radial 2c-2e sigma bonds. The resulting B84 (B(12)@B(12)@B(60)) retains the same symmetry as C60, and the B(n) (n=84-116) clusters are generated around it. We further project the possibility of producing such B12 based giant clusters.     

Synthesis and characterization of Y2Ti2O7 and ErxY2−xTi2O7 nanofibers

Journal of Sol-Gel Science and Technology - 1-D nanostructures are deemed to be important building blocks for future optical and optoelectronic nanodevices. We have used electrospinning methods to...     

Design,Synthesis, and Anti-Proliferative Activity of Some New Quinoxaline Containing 1,2,4-Thiadiazoles Amide Hybrids

Russian Journal of General Chemistry - A series of new quinoxaline-1,2,4-thiadiazoles amide hybrids has been synthesized and evaluated for their anti-proliferative activity on four different human...