Valentyn Stadnytskyi

Valentyn Stadnytskyi
National Institutes of Health | NIH · National Institute of Diabetes, Digestion and Kidney Diseases

Doctor of Philosophy

About

24
Publications
6,418
Reads
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1,356
Citations
Additional affiliations
January 2012 - present
Purdue University
Position
  • Research Assistant (PhD Candidate)
Description
  • Study of electronic structure of the Fenna-Matthews-Olson antenna protein complex. Time-resolved circular dichroism
Education
August 2011 - March 2017
Purdue University
Field of study
  • Biophysics
September 2009 - May 2011
National Taras Shevchenko University of Kyiv
Field of study
  • Physics: Laser and Optical Science
September 2005 - May 2009
National Taras Shevchenko University of Kyiv
Field of study
  • Physics: laser and Optical Science

Publications

Publications (24)
Article
BACKGROUND & AIMS Upper gastrointestinal (GI) endoscopy is speculated to be an aerosol-generating procedure (AGP). Robust evidence exists for aerosol transmission of SARS-CoV-2. The quality of data available confirming aerosol generation during GI endoscopy is limited. We aimed to objectively demonstrate that GI endoscopy is an AGP and illustrate t...
Article
Time-resolved small- and wide-angle X-ray scattering studies of proteins in solution based on the pump-probe approach unveil structural information from intermediates over a broad range of length and time scales. In spite of the promise of this methodology, only a fraction of the wealth of information encoded in scattering data has been extracted i...
Article
Full-text available
The SARS-CoV-2 virus is highly contagious, as demonstrated by numerous well-documented superspreading events. The infection commonly starts in the upper respiratory tract (URT) but can migrate to the lower respiratory tract (LRT) and other organs, often with severe consequences. Whereas LRT infection can lead to shedding of virus via breath and cou...
Article
Full-text available
Speech droplets generated by asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly considered to be a likely mode of disease transmission. Highly sensitive laser light scattering observations have revealed that loud speech can emit thousands of oral fluid droplets per second. In a closed, stagnant ai...
Preprint
Full-text available
Speaking may be a primary mode of transmission of SARS-CoV-2. Considering that reports of asymptomatic transmission account for 50-80% of COVID-19 cases and that saliva has peak viral loads at time of patient presentation, droplet emission while speaking could be a significant factor driving transmission and warrants further study. We used a planar...
Article
High efficiency of light harvesting in photosynthetic pigment-protein complexes is governed by evolutionary-perfected protein-assisted tuning of individual pigment properties and inter-pigment interactions. Due to the large number of spectrally overlapping pigments in a typical photosynthetic complex, experimental methods often fail to unambiguousl...
Article
The 2.5 Å structure of the cytochrome b6f complex provides a basis for control of the rate‐limiting electron transfer step of oxygenic photosynthesis associated with the plastoquinol/quinone exchange pathway. Here, a structural change was made at a site containing two proline residues which border the intra‐cytochrome pathway for plastoquinol/quino...
Article
Full-text available
It is well known that tetrameric hemoglobin binds ligands cooperatively by undergoing a ligand-induced T→R quaternary structure transition, a structure-function relationship that has long served as a model system for understanding allostery in proteins. However, kinetic studies of the reverse, R→T quaternary structure transition following photolysi...
Article
Full-text available
We describe an optical shot-noise limited time-resolved circular dichroism (TRCD) pump-probe spectrometer capable of reliably measuring {\mu}deg circular dichroism signal with nanosecond time resolution. Such improvement is achieved through modification of existing instrumentation designs and introduction a new data processing protocol that elimina...
Article
In this paper we report the steady-state optical properties of a series of site-directed mutants in the Fenna-Matthews-Olson (FMO) complex of Chlorobaculum tepidum, a photosynthetic green sulfur bacterium. The FMO antenna complex has historically been used as a model system for energy transfer due to the water-soluble nature of the protein, its sta...
Article
The intra-membrane cytochrome bc1 complex of the photosynthetic bacterium, Rhodobacter capsulatus, and the cytochrome b6f complex which functions in oxygenic photosynthesis, utilize two pairs of b-hemes in a symmetric dimer to accomplish proton-coupled electron transfer. The trans-membrane electron transfer pathway in each complex was identified th...
Article
The cytochrome b6f complex, a member of the cytochrome bc family that mediates energy transduction in photosynthetic and respiratory membranes, is a hetero-oligomeric complex that utilizes two pairs of b-hemes in a symmetric dimer to accomplish trans-membrane electron transfer, quinone oxidation-reduction, and generation of a proton electrochemical...
Article
Electron transfer in the dimeric cytochrome b6f complex, which includes four b-type hemes organized as two pairs in symmetric monomers, was studied by simultaneous measurement of the kinetics of heme reduction by dithionite and an associated amplitude increase of Soret band split circular dichroism (CD) spectra diagnostic of heme-heme exciton inter...
Article
The relaxation kinetics of laser-induced scattering and absorption was investigated in a liquid epoxy resin suspension of carbon microparticles. The scattered light intensity and the optical transmittance at temperatures below +10°C demonstrate anomalous kinetics with a distinct build-up stage. The observed behavior is interpreted as a manifestatio...
Article
Laser-induced incandescence (LII) of carbon microparticles in epoxy matrixes is studied. Non-monotonical behaviour of LII from doze of laser irradiation is observed. The proposed model interprets the majority of the observed experimental data.
Article
Full-text available
The effect of optical limiting is investigated in the suspensions of carbon microparticles in aqueous gelatin gel and epoxy resin. Both transient and permanent changes of optical transmittance are observed after the irradiation by a Q-switched YAG:Nd 3+ laser pulses. The experimental results are explained with taking into account the formation of m...
Article
Full-text available
PACS 44.40.+a, 78.90.+t, 82.70.Kj c Laser-induced incandescence (LII) of carbon microparticle suspen-sions in high-viscosity media under powerful excitation with a Q-switched neodymium laser has been investigated. The effect of LII buildup was detected, when suspensions of synthetic resins and polymers were irradiated with a sequence of laser pulse...

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Projects

Projects (4)
Project
The Fenna-Matthews-Olson (FMO) complex from green sulfur bacteria acts as an energy transfer wire, connecting the chlorosome complex (where most excitations are generated) to the reaction center (where charge--separation and electron transfer is performed). The goal of this project was to study the regulatory features of the complex and describe new energy transfer phenomena.