Functional Limit Theorems for the Fractional Ornstein–Uhlenbeck Process

Journal of Theoretical Probability - We prove a functional limit theorem for vector-valued functionals of the fractional Ornstein–Uhlenbeck process, providing the foundation for the...     

Drying of guaco leaves: experimental and modeling kinetic,equilibrium isotherms and heat of desorption

Journal of Thermal Analysis and Calorimetry - Due to the huge variety of therapeutic properties found in plant leaves, many of these are widely used in traditional medicine. Among these plants,...     

Design and Synthesis of High‐Affinity Dimeric Inhibitors Targeting the Interactions between Gephyrin and Inhibitory Neurotransmitter Receptors

Gephyrin is the central scaffolding protein for inhibitory neurotransmitter receptors in the brain. Here we describe the development of dimeric peptides that inhibit the interaction between gephyrin and these receptors, a process which is fundamental to numerous synaptic functions and diseases of the brain. We first identified receptor‐derived minimal gephyrin‐binding peptides that displayed exclusive binding towards native gephyrin from brain lysates. We then designed and synthesized a series of dimeric ligands, which led to a remarkable 1220‐fold enhancement of the gephyrin affinity (K_D=6.8 nM ). In X‐ray crystal structures we visualized the simultaneous dimer‐to‐dimer binding in atomic detail, revealing compound‐specific binding modes. Thus, we defined the molecular basis of the affinity‐enhancing effect of multivalent gephyrin inhibitors and provide conceptually novel compounds with therapeutic potential, which will allow further elucidation of the gephyrin–receptor interplay.     

Electrogenerated Chemiluminescence of Cationic Triangulene Dyes: Crucial Influence of the Core Heteroatoms

Trianguleniums are fascinating conjugated hexacyclic cations that exhibit interesting electronic and optical properties. Herein, the electrogenerated chemiluminescence (ECL) emission of this family of fluorescent dyes is reported for the first time. Redox behavior and fluorescence properties of eight cationic triangulene luminophores with different heteroatom patterns in the core structure and various pending substituents were examined to rationalize the ECL. Clearly, the more electron‐rich the carbocation, the more efficient the corresponding ECL; two very distinct classes of triangulenes can be drawn from these studies by using an ECL wall sufficiency formalism.     

Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography

A collaborative study on the robustness and portability of a capillary electrophoresis‐mass spectrometry method for peptide mapping was performed by an international team, consisting of 13 independent laboratories from academia and industry. All participants used the same batch of samples, reagents and coated capillaries to run their assays, whereas they utilized the capillary electrophoresis‐mass spectrometry equipment available in their laboratories. The equipment used varied in model, type and instrument manufacturer. Furthermore, different types of sheath‐flow capillary electrophoresis–mass spectrometry interfaces were used. Migration time, peak height and peak area of ten representative target peptides of trypsin‐digested bovine serum albumin were determined by every laboratory on two consecutive days. The data were critically evaluated to identify outliers and final values for means, repeatability (precision within a laboratory) and reproducibility (precision between laboratories) were established. For relative migration time the repeatability was between 0.05 and 0.18% RSD and the reproducibility between 0.14 and 1.3% RSD. For relative peak area repeatability and reproducibility values obtained were 3–12 and 9–29% RSD, respectively. These results demonstrate that capillary electrophoresis‐mass spectrometry is robust enough to allow a method transfer across multiple laboratories and should promote a more widespread use of peptide mapping and other capillary electrophoresis‐mass spectrometry applications in biopharmaceutical analysis and related fields.     

The Reaction of Cs2[Tc(NO)F5] with BF3 in Acetonitrile: Formation and Structure of [{Tc(NO)(CH3CN)4}2(μ‐F)](BF4)3

The deep blue, paramagnetic Cs₂[Tc^II(NO)F₅] is formed during reactions of pertechnetate, acetohydroxamic acid, and CsF in aqueous HF. A reaction of Cs₂[Tc(NO)F₅] with BF₃ · MeOH in acetonitrile gives yellow blocks of the fluorido‐bridged dimer [{Tc^I(NO)(CH₃CN)₄}₂F](BF₄)₃. The compound is stable as solid and in acetonitrile solutions. The complex cation contains a bent μ‐F^– ligand and two linear nitrosyl groups.     

Recent Progress in the Simulation of Chiral Systems with Real Time Propagation Methods

In this brief review, an overview about recent efforts to simulate the spectroscopic signatures of chiral molecules is given with focus on real time propagation approaches to solve the time-dependent Schrödinger equation. In particular the simulation of electric circular dichroism spectra and vibrational Raman optical activity is discussed. In comparison to linear absorption spectra, where only the response of the electric dipole moment is necessary, the response of the magnetic dipole moment and electric quadrupole moment is more intricate. Issues such as gauge origin dependence, basis set dependence, non-local potentials and the dipole approximation are addressed.     

Batch tautomer generation with MolTPC

Besides all their conformational degrees of freedom, drug‐like molecules and natural products often also undergo tautomeric interconversions. Compared to the huge efforts made in experimental investigation of tautomerism, open and free algorithmic solutions for prototropic tautomer generation are surprisingly rare. The few freely available software packages limit their output to a subset of the possible configurational space by sometimes unwanted prior assumptions and complete neglection of ring‐chain tautomerism. Here, we describe an adjustable fully automatic tautomer enumeration approach, which is freely available and also incorporates the detection of ring‐chain variants. The algorithm is implemented in the MolTPC framework and accessible on SourceForge. © 2013 Wiley Periodicals, Inc.     

FIBSIMS: A review of secondary ion mass spectrometry for analytical dual beam focussed ion beam instruments

Secondary ion mass spectrometry (SIMS) is a well-known technique for 3D chemical mapping at the nanoscale, with detection sensitivity in the range of ppm or even ppb. Energy dispersive X-ray spectroscopy (EDS) is the standard chemical analysis and imaging technique in modern scanning electron microscopes (SEM), and related dual-beam focussed ion beam (FIBSEM) instruments. Contrary to the use of an electron beam, in the past the ion beam in FIBSEMs has predominantly been used for local milling or deposition of material. Here, we review the emerging FIBSIMS technique which exploits the focused ion beam as an analytical probe, providing the capability to perform secondary ion mass spectrometry measurements on FIBSEM instruments: secondary ions, sputtered by the FIB, are collected and selected according to their mass by a mass spectrometer. In this way a complete 3D chemical analysis with high lateral resolution <?50 nm and a depth resolution <?10 nm is attainable.We first report on the historical developments of both SIMS and FIB techniques and review recent developments in both instruments. We then review the physics of interaction for incident particles using Monte Carlo simulations. Next, the components of modern FIBSIMS instruments, from the primary ion generation in the liquid metal source in the FIB column, the focussing optics, the sputtered ion extraction optics, to the different mass spectrometer types are all detailed. The advantages and disadvantages of parallel and serial mass selection in terms of data acquisition and interpretation are highlighted, while the effects of pressure in the FIBSEM, acceleration voltage, ion take-off angles and charge compensation techniques on the analysis results are then discussed. The capabilities of FIBSIMS in terms of sensitivity, lateral and depth resolution and mass resolution are reviewed. Different data acquisition strategies related to dwell time, binning and beam control strategies as well as roughness and edge effects are discussed. Data analysis routines for mass identification based on isotope ratios and molecular fragments are outlined. Application examples are then presented for the fields of thin films, polycrystalline metals, batteries, cultural heritage materials, isotope labelling, and geological materials. Finally, FIBSIMS is compared to EDS, and the potential of the technique for correlative microscopy with other FIBSEM based imaging techniques is discussed.