Development of a new particulate 4-μm adsorbent layer for ultrathin-layer chromatography (miniaturized chromatogram).

The performance of particulate layers of a smaller particle size than given HPTLC plates was investigated. However, reducing the particle size and thus interporous space, the capillary flow is substantially reduced. For the first time, optimizations led to the successful use of a layer made of mainly 4-μm irregular silica gel particles as stationary phase in planar chromatography.

Fast Equivalency Estimation of Unknown Enzyme Inhibitors in Situ the Effect-Directed Fingerprint, Shown for Bacillus Lipopeptide Extracts.

The hyphenation of high-performance thin-layer chromatography (HPTLC) with enzyme inhibition assays followed by high-resolution mass spectrometry (HRMS) represents a targeted profiling of complex natural samples required in the development of new natural pharmaceuticals, functional foods, and cosmetics. This direct combination of a chromatogram with an enzymatic assay substantially extents the understanding of inhibitor properties in vitro. For the first time, a straightforward workflow was established for estimating the equivalency of unknown inhibitors directly in the autogram.

eicCluster software, an open-source in silico tool, and on-surface syntheses, an in situ concept, both exploited for signal highlighting in high-resolution mass spectrometry to ease structure elucidation in planar chromatography.

Optimization of the ionization parameters in mass spectrometry does not guarantee a sufficient response and successful signal assignment when analyzing unknown compounds presenting signals of low intensity. The interpretation is difficult as the mass signals of degradation products are often less intense than background signals. Important information may be overlooked.

Office Chromatography: Miniaturized All-in-One Open-Source System for Planar Chromatography.

Current high-performance-thin-layer-chromatography instrumentation is offline and stepwise automated. However, moderate miniaturization offers many advantages and together with the transfer of modern print and media technologies to the field of chromatography (office chromatography) it opens up new avenues. This is demonstrated in an all-in-one open-source system developed for planar chromatography and especially for ultrathin-layer chromatography.

All on one high-performance thin-layer chromatography plate: solvent-free nanomole-scaled on-surface synthesis, workup and online high-resolution mass spectrometry for elucidation of two new degradation products in an ifosfamide formulation.

On-surface reactions were introduced as a new strategy for rapid structure elucidation. This strategy is illustrated by the miniaturized synthesis-guided identification of two new degradation products (impurities) occurring in a pharmaceutical formulation of the anti-cancer drug ifosfamide, especially in the presence of urea. Synthesis on the silica gel surface bypassed the need for solvents, as the large nm-porous surface favoured a fast conversion of the reaction partners.

Direct bioautography hyphenated to direct analysis in real time mass spectrometry: Chromatographic separation, bioassay and mass spectra, all in the same sample run.

Mass spectra were recorded directly in situ the bioautogram, i.e., in the presence of microorganisms, bioassay medium and substrate reagent.

Endotoxinemia contributes to steatosis, insulin resistance and atherosclerosis in chronic hepatitis C: the role of pro-inflammatory cytokines and oxidative stress.

Purpose: Endotoxin is a component of the outer membrane of gram-negative bacteria that live in the intestine. Endotoxinemia is reported in non-alcoholic fatty liver disease and in cirrhotic patients, causing various biological and clinical effects in the host. It is not known whether endotoxinemia occurs in chronic hepatitis C patients (CHC), therefore we evaluated the occurrence of endotoxinemia and its effect on inflammation, liver damage, insulin resistance (IR) and atherosclerosis.

Simultaneous determination of mono-, di-, oligo- and polysaccharides via planar chromatography in 4 different prebiotic foods and 60 naturally degraded inulin samples.

Oligo- and polysaccharides, especially fructooligosaccharides and inulin, are increasingly used as food ingredients. They are reported to stimulate the growth of bifidobacteria and are therefore used as prebiotics. As mono-, di-, oligo- and polysaccharides can together be present in food, an HPTLC method was developed for analyzing all in a single development.

Bioprofiling of Cosmetics with Focus on Streamlined Coumarin Analysis.

Facing the widespread use of cosmetic products in daily use and recognizing the very limited information obtained by target analysis, a method suited for comprehensive characterization of cosmetics was aimed at. The biological activity of ingredients of 20 cosmetics taken from 16 different product groups and their coumarin contents were investigated via chromatography linked to bioassays (direct bioautography) and mass spectrometry. It allows for screening a large number of cosmetic products within a short time to generate a more valid database on their coumarin content and their contribution to the overall exposure.

Electromagnetic Energy Redistribution in Coupled Chiral Particle Chain-Film System.

Metal nanoparticle-film system has been proved that it has the ability of focusing light in the gap between particle and film, which is useful for surface-enhanced Raman scattering and plasmon catalysis. The rapid developed plasmonic chirality can also be realized in such system. Here, we investigated an electromagnetic energy focusing effect and chiral near-field enhancement in a coupled chiral particle chain on gold film.

quanTLC, an online open-source solution for videodensitometric quantification.

The image is the key feature of planar chromatography. Videodensitometry by digital image conversion is the fastest way of its evaluation. Instead of scanning single sample tracks one after the other, only few clicks are needed to convert all tracks at one go.

Powerful Artificial Neural Network for Planar Chromatographic Image Evaluation, Shown for Denoising and Feature Extraction.

An artificial neural network (ANN) is presented as a new and superior technique for processing planar chromatography images. Though several algorithms are available for image processing in planar chromatography, the use of ANN has not been explored so far. It simulates how the human brain interprets images, and the intrinsic features of the image were captured on patches of pixels and successfully reconstructed afterward.

Effect-directed classification of biological, biochemical and chemical profiles of 50 German beers.

Biological and biochemical fingerprints were investigated for the first time for the feasibility of effect-directed classification, and thus, to allow the choice of a distinct beer with regard to beneficial health effects. A high-performance thin-layer chromatography method was newly developed and combined with in situ effect-directed analysis for profiling 50 German beers for multipotent active compounds, and thus, their health-related potential. Discovered multipotent active zones were online eluted and characterized by high resolution mass spectrometry.

Electromagnetic Field Redistribution in Metal Nanoparticle on Graphene.

Benefiting from the induced image charge on metal film, the light energy is confined on a film surface under metal nanoparticle dimer, which is called electromagnetic field redistribution. In this work, electromagnetic field distribution of metal nanoparticle monomer or dimer on graphene is investigated through finite-difference time-domain method. The results point out that the electromagnetic field (EM) redistribution occurs in this nanoparticle/graphene hybrid system at infrared region where light energy could also be confined on a monolayer graphene surface.

Simulating the ideal geometrical and biomechanical parameters of the pulmonary autograft to prevent failure in the Ross operation.

Objectives: Reinforcements for the pulmonary autograft (PA) in the Ross operation have been introduced to avoid the drawback of conduit expansion and failure. With the aid of an in silico simulation, the biomechanical boundaries applied to a healthy PA during the operation were studied to tailor the best implant technique to prevent reoperation.

Methods: Follow-up echocardiograms of 66 Ross procedures were reviewed.

Analysis of unauthorized Sudan dyes in food by high-performance thin-layer chromatography.

Food authenticity and food safety are of high importance to organizations as well as to the food industry to ensure an accurate labeling of food products. Respective analytical methods should provide a fast screening and a reliable cost-efficient quantitation. HPTLC was pointed out as key analytical technique in this field.

Discovered acetylcholinesterase inhibition and antibacterial activity of polyacetylenes in tansy root extract via effect-directed chromatographic fingerprints.

The knowledge about the activity of polyacetylenes was extended by their new acetylcholinesterase inhibition and antibacterial activity against plant pathogenic bacteria. For this discovery, an utmost streamlined workflow, which we consider to be of high potential in the field of natural product or superfood search was developed. It demonstrates the combined power of biological, biochemical and chemical fingerprints.

How the microbiome challenges our concept of self.

Today, the three classical biological explanations of the individual self--the immune system, the brain, the genome--are being challenged by the new field of microbiome research. Evidence shows that our resident microbes orchestrate the adaptive immune system, influence the brain, and contribute more gene functions than our own genome. The realization that humans are not individual, discrete entities but rather the outcome of ever-changing interactions with microorganisms has consequences beyond the biological disciplines.

Effect-directed analysis via hyphenated high-performance thin-layer chromatography for bioanalytical profiling of sunflower leaves.

High-performance thin-layer chromatography (HPTLC) coupled with effect-directed analysis was used for non-targeted screening of sunflower leaf extract for components exhibiting antioxidant, antibacterial and/or cholinesterase enzyme inhibitory effects. The active compounds were characterized by HPTLC-electrospray ionization-high resolution mass spectrometry (ESI-HRMS) and HPTLC-Direct Analysis in Real Time (DART)-MS/MS. The latter ambient ionization technique (less soft than ESI) resulted in oxidation and fragmentation products and characteristic fragment ions.

Hypoxia-inducible factor 2α drives nonalcoholic fatty liver progression by triggering hepatocyte release of histidine-rich glycoprotein.

Unlabelled: Mechanisms underlying progression of nonalcoholic fatty liver disease (NAFLD) are still incompletely characterized. Hypoxia and hypoxia-inducible factors (HIFs) have been implicated in the pathogenesis of chronic liver diseases, but the actual role of HIF-2α in the evolution of NAFLD has never been investigated in detail. In this study, we show that HIF-2α is selectively overexpressed in the cytosol and the nuclei of hepatocytes in a very high percentage (>90%) of liver biopsies from a cohort of NAFLD patients at different stages of the disease evolution.

A secreted antibacterial neuropeptide shapes the microbiome of Hydra.

Colonization of body epithelial surfaces with a highly specific microbial community is a fundamental feature of all animals, yet the underlying mechanisms by which these communities are selected and maintained are not well understood. Here, we show that sensory and ganglion neurons in the ectodermal epithelium of the model organism hydra (a member of the animal phylum Cnidaria) secrete neuropeptides with antibacterial activity that may shape the microbiome on the body surface. In particular, a specific neuropeptide, which we call NDA-1, contributes to the reduction of Gram-positive bacteria during early development and thus to a spatial distribution of the main colonizer, the Gram-negative Curvibacter sp.

Analyzing intrinsic plasmonic chirality by tracking the interplay of electric and magnetic dipole modes.

Plasmonic chirality represents significant potential for novel nanooptical devices due to its association with strong chiroptical responses. Previous reports on plasmonic chirality mechanism mainly focus on phase retardation and coupling. In this paper, we propose a model similar to the chiral molecules for explaining the intrinsic plasmonic chirality mechanism of varies 3D chiral structures quantitatively based on the interplay and mixing of electric and magnetic dipole modes (directly from electromagnetic field numerical simulations), which forms mixed electric and magnetic polarizability.

Hollow Au-Ag Alloy Nanorices and Their Optical Properties.

Hollow noble metal nanoparticles have excellent performance not only in surface catalysis but also in optics. In this work, the hollow Au-Ag alloy nanorices are fabricated by the galvanic replacement reaction. The dark-field spectrum points out that there is a big difference in the optical properties between the pure Ag nanorices and the hollow alloy nanorices that exhibit highly tunable localized surface plasmon resonances (LSPR) and that possess larger radiative damping, which is also indicated by the finite element method.