An efficient synthetic approach towards a single diastereomer of (2R,3R)-N2,N3-bis((S)-1-phenylethyl)butane-2,3-diamine via metalation and demetalation

Transition Metal Chemistry - A facile synthetic approach has been adopted towards the synthesis of (2R,3R)-N2,N3-bis((S)-1-phenylethyl)butane-2,3-diamine via demetalation of its dichloro Zn(II)...     

Amino-acid-mediated epoxidation of α,β-unsaturated ketones by hydrogen peroxide in aqueous media

Amino acids, such as arginine and lysine, can be used as an efficient catalyst in the epoxidation of α,β-unsaturated ketones with aqueous hydrogen peroxide. Up to >99% conversion was obtained in the reaction toward 11 α,β-unsaturated ketones.     

Pion–Rho Meson Lagrangian in Nuclear Matter

We present an in-medium modified pion and rho meson Lagrangian which describes the pion, rho meson and the corresponding soliton properties in nuclear matter. Within the present approach pion properties in nuclear matter is closely related to the low-energy pion-nucleus scattering phenomenology. We discuss the possible modifications of rho meson properties in nuclear matter.     

Synthesis,characterisation, and X-ray structures of zinc(II) complexes bearing camphor-based ethyleneamineimines as pre-catalysts for heterotactic-enriched polylactide from rac-lactide

Transition Metal Chemistry - A series of Zn(II) complexes bearing camphor-based ethyleneamine derivatives, [LnZnCl2]...     

Ion conducting properties of poly(ethylene oxide)-based electrolytes incorporating amorphous silica attached with imidazolium salts

Poly(ethylene oxide) (PEO)-based polymer electrolytes containing amorphous silica attached ionic liquid (IL) were studied in order to improve electrochemical and interfacial properties. An imidazolium salt such as IL was attached to modified ceramic fillers. The modified ceramic fillers were amorphous silica with the immobilized 1-methyl-3-propyl-imidazolium bromide (MPIm-AS). PEO-based polymer electrolytes were prepared by using the solution casting technique. In order to investigate the ionic conductivity, studies on the modified filler addition effects on the ion-conducting behavior of polymer electrolytes having specific amounts of MPIm-AS were carried out. The addition of MPIm-AS in polymer electrolytes has resulted in higher ionic conductivity at room temperature. The structure, crystallinity, and morphology of the solid polymer electrolytes were evaluated using X-ray diffraction, differential scanning calorimetry, and scanning electron microscope measurement. The ionic conductivity was measured by an AC impedance method. The enhanced conductivity was dependent on the decreased crystallinity and the changed morphologies of composites.     

Soybean Hulls Pretreated Using Thermo-Mechanical Extrusion—Hydrolysis Efficiency,Fermentation Inhibitors,and Ethanol Yield

Soybean hulls were subjected to thermo-mechanical extrusion pretreatment at various in-barrel moisture contents and screw speeds. Extrusion degraded the lignocellulosic structure and enhanced enzymatic hydrolysis of soybean hulls, with up to 155% increase in glucose yield as compared to untreated substrate. Greater glucose yields were observed at higher in-barrel moistures (45% and 50%) and lower screw speed (280 and 350 rpm). Maximum 74% cellulose to glucose conversion resulted from using a two-enzyme cocktail consisting of cellulase and β-glucosidase. Conversion increased to 87% when a three-enzyme cocktail having a cell wall degrading enzyme complex was used for hydrolysis. Fermentation inhibitors, such as furfural, 5-(hydroxymethyl)-2-furaldehyde (HMF), and acetic acid, were found in the extrusion pretreated soybean hulls and hydrolysate. However, their concentrations were below the known thresholds for inhibition. Fermentation of hydrolysate by Saccharomyces cerevisiae led to high yields of ethanol, with concentration ranging from 13.04 to 15.44 g/L.     

Algorithms for Fitting the Constrained Lasso

We compare alternative computing strategies for solving the constrained lasso problem. As its name suggests, the constrained lasso extends the widely used lasso to handle linear constraints, which allow the user to incorporate prior information into the model. In addition to quadratic programming, we employ the alternating direction method of multipliers (ADMM) and also derive an efficient solution path algorithm. Through both simulations and benchmark data examples, we compare the different algorithms and provide practical recommendations in terms of efficiency and accuracy for various sizes of data. We also show that, for an arbitrary penalty matrix, the generalized lasso can be transformed to a constrained lasso, while the converse is not true. Thus, our methods can also be used for estimating a generalized lasso, which has wide-ranging applications. Code for implementing the algorithms is freely available in both the Matlab toolbox SparseReg and the Julia package ConstrainedLasso. Supplementary materials for this article are available online.     

Ultra-fast Cycling for Multiplexed Cellular Fluorescence Imaging

Rapid analysis of single and scant cell populations is essential in modern diagnostics, yet existing methods are often limited and slow. Herein, we describe an ultra-fast, highly efficient cycling method for the analysis of single cells based on unique linkers for tetrazine (Tz)/trans-cyclooctene (TCO)-mediated quenching. Surprisingly, the quenching reaction rates were more than 3 orders of magnitude faster (t_1/2 <1 s) than predicted. This allowed multi-cycle staining and immune cell profiling within an hour, leveraging the accelerated kinetics to open new diagnostic possibilities for rapid cellular analyses.     

Synthesis and structures of copper complexes bearing unsymmetric derivatives of (R,R)‐1,2‐diaminocyclohexane: An efficient catalyst for asymmetric Henry reaction

A series of Cu (II) complexes bearing asymmetric derivatives of (R,R)‐1,2‐diaminocyclohexane were synthesised and characterised. The X‐ray structures of the complexes showed distorted square planar geometry. The catalytic activities of in situ‐generated copper acetate complexes in the presence of 10 mol% of N,N‐diisopropylethylamine were evaluated in the asymmetric Henry reaction. The current catalysts showed high enantioselectivity (up to 99%) for (S)‐1‐nitro‐4‐phenylbutan‐2‐ol from the reaction of 3‐phenylpropanal and nitromethane.     

Layer‐by‐Layer Spin Self‐Assembled Hole Injection Layers Containing a Perfluorinated Ionomer for Efficient Polymer Light‐Emitting Diodes

Deposition of hole injection layers including a perfluorinated ionomer has been demonstrated using layer‐by‐layer spin self‐assembly for enhanced device efficiency and lifetime in PLEDs. We show that the LBL spin self‐assembled thin films enable to control work functions of indium‐tin oxide anodes by changing the PFI concentration and that a resulting green‐emitting device has an enhanced luminescence efficiency and 18 times longer half lifetime than a device using a conventional HIL. We also fabricate a gradient of energy levels by the LBL self‐assembly of the PFI that results in a work function of 5.74 eV, which can be used to improve carrier injection even for an emitting layer whose ionization potential is over 5.7 eV.