Color confinement and long-distance color fields in QCD

We use an effective lagrangian previously derived from a long-distance self-consistent solution of the Schwinger-Dyson equations of Yang-Mills theory to study some long-distance problems in QCD. In particular we show: (i) the long-distance contribution to the energy of a system containing a net color electric charge is infinite and hence there are no such states in the physical spectrum; (ii) the long-distance contribution to the energy of a system containing a net color magnetic charge is completely screened at distances r > 1/Λ_rmQCD.     

Behavioral effects of exposure to nuclear magnetic resonance imaging: II. Spatial memory tests

In order to determine possible effects of exposure to nuclear magnetic resonance imaging (MRI) on cognitive processes, the performance of imaged, sham exposed, and control rats on a spatial memory task was examined. This particular task was chosen because, under some conditions, animals use the magnetic field as a compass when navigating. The rats were required to collect food from eight different locations before returning to an already chosen location. All three groups of rats achieved a high level of performance, and there were no differences between groups in any of the performance measures examined. These results indicate that the MRI procedure has no significant effect on spatial memory processes in rats.     

Arylsulfenylation of 2,3-dialkylindoles; preparation of 3-arylthioindolenines and thermal conversion to an n-sulfenylindole

Reaction of 2,3-dialkylindoles with o-nitrophenylsulfenyl chloride in the presence of triethylamine gives good yields of previously unknown 3-o-nitrophenylsulfenyl-2,3-dialkylindolenines which decompose thermally to give the corresponding 2,3-dialkylindole and N₁-o-nitrophenylsulfenyl indoles.     

Towards High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry Coupled to Shear Force Microscopy

Constant mode ambient mass spectrometry imaging (MSI) of tissue sections with high lateral resolution of better than 10 μm was performed by combining shear force microscopy with nanospray desorption electrospray ionization (nano-DESI). Shear force microscopy enabled precise control of the distance between the sample and nano-DESI probe during MSI experiments and provided information on sample topography. Proof-of-concept experiments were performed using lung and brain tissue sections representing spongy and dense tissues, respectively. Topography images obtained using shear force microscopy were comparable to the results obtained using contact profilometry over the same region of the tissue section. Variations in tissue height were found to be dependent on the tissue type and were in the range of 0–5 μm for lung tissue and 0–3 μm for brain tissue sections. Ion images of phospholipids obtained in this study are in good agreement with literature data. Normalization of nano-DESI MSI images to the signal of the internal standard added to the extraction solvent allowed us to construct high-resolution ion images free of matrix effects.

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Graphical Abstract ?

     

Kemp elimination in cationic micelles: designed enzyme‐like rates achieved through the addition of long‐chain bases

The Kemp elimination is prototypical reaction used to study proton abstraction from carbon. Several hydrophobic systems are known to accelerate this reaction, including two classes of computationally designed enzymes. However, it is unclear whether these computationally designed enzymes establish specific interactions with their substrates, as natural enzymes do, or if most of the rate acceleration is due to the hydrophobicity of the substrate. We used a simple system composed of cationic micelles and a long chain base (such as lauryl phosphate or lauric acid) to measure the rate acceleration for the Kemp elimination. Remarkably, we found that this simple system can accelerate the reaction by four orders of magnitude, approaching the rates of more complex designed systems. Use of different substrates suggests that the reaction takes place at the interface between the micellar head and water (the Stern layer) with the long‐chain base embedded in the micelle and the substrate in the aqueous solution. Thus, we suggest that significant rate accelerations can be achieved regardless of the precise positioning of substrates. Because natural enzymes use specific interactions to position their substrates, we propose that acceleration of the Kemp elimination is not a suitable benchmark for the success of the design process, and we suggest that more complex reactions should be used. Copyright © 2015 John Wiley & Sons, Ltd.     

Osteoblast Adhesion and Proliferation on Poly(3‐octylthiophene) Thin Films

In this study we assessed the suitability of semiconducting P3OT thin films (30 nm) to sustain attachment, spreading, and proliferation of MC3T3‐E1 osteoblasts. Cell area correlated with surface wettability: area was larger on the more hydrophilic surface (TCPS) and lower on the more hydrophobic surface (P3OT). Cells were rounder, characterized by higher circularity values, on TCPS and Si compared to P3OT. P3OT proliferation rate at 24 h fell twofold after 48 h, then recovered at 72 h to a value significantly higher than that on TCPS. Presoaking experiments showed no evidence of cytotoxic effects or leachants from P3OT. Overall, we conclude that P3OT is a viable substrate for osteoblast attachment and proliferation.