A5057002822- Photoreceptor and optogenetics research
- Advanced Glycation End Products research
- Neuroscience and Neural Engineering
- Neural dynamics and brain function
- Tea Polyphenols and Effects
- Phytochemicals and Antioxidant Activities
- Religion, Gender, and Enlightenment
- Force Microscopy Techniques and Applications
- Natural product bioactivities and synthesis
- Bacterial biofilms and quorum sensing
- Natural Antidiabetic Agents Studies
- American Constitutional Law and Politics
- Carbohydrate Chemistry and Synthesis
- Reformation and Early Modern Christianity
- Biochemical and Structural Characterization
- Phytoestrogen effects and research
- Surface Chemistry and Catalysis
- Molecular Communication and Nanonetworks
- Vietnamese History and Culture Studies
- Molecular Junctions and Nanostructures
- Phytochemical Studies and Bioactivities
- Advanced Memory and Neural Computing
- Ginseng Biological Effects and Applications
- Analytical Chemistry and Chromatography
- Diet, Metabolism, and Disease
University College London
2024
Newcastle University
2019-2024
Bioengineering Center
2024
University of St Andrews
2018-2019
University of Sheffield
2014-2015
Queen's University
2001-2011
University of Reading
1991-2005
University of Waterloo
1990-1991
ABSTRACT Most bacterial cells are enclosed in a single macromolecule of the cell wall polymer, peptidoglycan, which is required for shape determination and maintenance viability, while peptidoglycan biosynthesis an important antibiotic target. It hypothesized that cellular enlargement requires regional expansion through coordinated insertion hydrolysis peptidoglycan. Here, group (apparent glucosaminidase) hydrolases identified together correct morphology Staphylococcus aureus , demonstrating...
Abstract The non‐volatile, water‐soluble constituents of black tea were studied by using reversed‐phase HPLC with a photodiode‐array detector, linear gradient developed for this purpose. data generated detector from one injection liquor allowed information on the nature and purity to be obtained. following identified spectral retention times given reference compounds: caffeine, theobromine, (−)‐epicatechin gallate, (−)‐ epigallocatechin gallic acid, chlorogenic acid (5‐O‐caffeoylquinic...
Abstract A brown thearubigin fraction was isolated from a black tea liquor, using chromatography on column of Solka‐Floc cellulose. The paper chromatograms the resembled fractions produced in past. substance contained no protein or caffeine, and free flavonol glycosides. Reversed phase HPLC showed to be mixture polymers, showing convex broad band. Infra‐red spectroscopy phenolic, 13 C NMR it flavanol polymer with various linkages proanthocyanidin polymers. spectra this are first polymeric...
Abstract The chemical oxidation of polyphenols has been used to produce black tea pigments. (+)‐Catechin, (−)‐epicatechin, (−)‐epicatechin gallate and (−)‐epigallocatechin were isolated from convenient sources, their identity being confirmed by mass spectrometry HPLC. a mixture gallic acid gave an product in addition epitheaflavic 3‐gallate. catechins oxidised chemically the products analysed HPLC, chromatograms compared with chromatogram. reactions both resolved unresolved pigments, many...
An HPLC-diode array detection (HPLC-DAD) method was developed for the direct analysis of reaction products aqueous Maillard model systems. The applied to mixtures xylose or glucose refluxed with glycine lysine up 120 min pH maintained at 5 throughout heating. Four types chromatographic behaviour were apparent, ie unretained peaks, resolved peaks and two broad bands. Glycine systems dominated by while based on showed all four behaviour. By reference HPLC-DAD data standard compounds, some...
Melchior Hoffman, the Swabian furrier turned Reformation lay preacher, played a minor role in early stages of Danish Reformation, as polemicist, and printer. This paper will address some remaining problems narrative Hoffman's tenure reassess longstanding interpretations.
Aqueous sugar (xylose or glucose)−glycine model systems were refluxed for 2 h with the pH maintained at 5. Reverse-phase HPLC of total reaction products gave two resolved peaks (one which was colored) xylose system and five (two glucose system. The components responsible these isolated from ethyl acetate extracts by semipreparative HPLC. Using mainly NMR, colored compound identified as new 2-acetyl-6-(hydroxymethyl)-5,6-dihydro-4H-pyridinone. compounds most likely to be novel cis/trans ring...
Brain-machine Interfaces (BMI) hold great potential for treating neurological disorders such as epilepsy. Technological progress is allowing a shift from open-loop, pacemaker-class, intervention towards fully closed-loop neural control systems. Low power programmable processing systems are therefore required which can operate within the thermal window of 2° C medical implants and maintain long battery life. In this work, we have developed low engine with an optimized set algorithms under...
Abstract This paper describes the application of liquid chromatography‐mass spectrometry to analysis a black tea liquor, and shows that much useful information can be obtained without sample pretreatment. A liquor was applied wide‐pore high‐performance liquid‐chromatography column connected mass spectrometer by VG Plasmaspray interface. Pseudo‐molecular ions were from flavanols, flavanol gallates, chlorogenic acids, 4‐coumarylquinic caffeine, but flavonol glycosides extensively fragmented...
Abstract The HPLC chromatograms, mass spectra, and acid degradation of a theafulvin fraction (a polymeric thearubigins) proanthocyanidin polymers from cider wine were compared. cider, wine, fractions ran as broad bands on Hamilton PRP‐1 column. gave positive‐ion FAB spectra characteristic polymers, but the theafulvins low‐molecular‐mass flavanol fragments only. cyanidin degradation, reaction products being analysed by mainly material that close to void volume These experiments provided...
Abstract Electrical neurostimulation is effective in treating neurological disorders, but associated recording artefacts generally limit applications to ‘open-loop’ stimuli. Since light does not prevent concurrent electrical recordings, optogenetics enables real-time, continuous ‘closed-loop’ control of brain activity. Here we show that closed-loop optogenetic stimulation with excitatory opsins (CLOSe) affords precise manipulation neural dynamics, both vitro , slices from transgenic mice,...
Aqueous sugar (glucose or xylose)-lysine model systems were heated at 80 degrees C for 6 h with the pH maintained a predetermined value (3, 4, 5). Selected compounds isolated by combinations of solvent extraction and semipreparative HPLC, prior to identification NMR mass spectrometry. Two identified from 5 glucose system as epsilon-[2-formyl-5-(hydroxymethyl)pyrrole-1-yl]-L-norleucine (pyrraline) new compound, 1-(5-carboxy-5-aminopentyl)-2-formyl-3-(1,2,3-trihydroxypropyl)pyrrole. A third...
Neuromodulation is an established treatment for numerous neurological conditions, but to expand the therapeutic scope there a need improve spatial, temporal and cell-type specificity of stimulation. Optogenetics promising area current research, enabling optical stimulation genetically-defined cell types without interfering with concurrent electrical recording closed-loop control neural activity. We are developing open-source system provide platform optogenetic neuromodulation, incorporating...
Traditional methods to prepare chiral surfaces involve either the adsorption of a molecule onto an achiral surface, or species that forms template creating lattices with long range order. To date only limited alternative strategies have been studied. In this manuscript "bottom-up" approach is developed allows preparation by direct enantioselective organocatalytic reactions on functionalized silicon oxide supported self-assembled monolayer (SAM). The efficient catalytic generation...
Activation and suppression of the complement system compete on every serum-exposed surface, host or foreign. Potentially harmful outcomes this competition depend surface molecules through mechanisms that remain incompletely understood. Combining plasmon resonance (SPR) with atomic force microscopy (AFM), here we studied two proteins at single-molecule level: C3b, proteolytically activated form C3, factor H (FH), surface-sensing C3b-binding regulator. We used SPR to monitor initiation...