Tatyana Khromova

Russian Academy of Sciences | RAS · Institute of Biophysics

The results of 20 years of field data (1963–1982) and 50 years of remote observations (1963–2012) on Medvezhy Glacier in the Pamirs by the Institute of Geography, Russian Academy of Sciences, are considered. The prevalence of the influence of climatic factors over internal ones (features of ice deformation) on glacial surges is shown. A conclusion...

This paper reports that in the period of global warming continuing over 150 years, there are the glaciers growing in size.

Contemporary conditions and dynamics of glaciers in mountain areas of Russia have been evaluated based on satellite imagery interpretations and field surveys, analysis of the data of the Glacier Inventory of the USSR, topographic maps and aerial photographs, as well as published research papers. Glacier systems in Russia have been studied unevenly...

Changes of the glacier areas were analyzed. Rates of the area reduction of glaciers and glacier systems were compared over the course of the past 160 years as well as during shorter time intervals for the same period. On average for the whole period, the glacier areas decreased by a few tenths of a percent from the original in a year. Note, that th...

Based on systematic surveys and analysis of the satellite images under the GLIMS international project, the rate of glacier shrinkage and the increase in this rate for the past 15 years are estimated.

The history of studies of ten mountain glacier systems in Russian Subarctic is analyzed in the paper (Fig. 1). The intensity of these systems reduction and the vertical extent of glaciers during last 150 and 50 years are compared with the climate warming in this part of Russia, the map of accumulation–ablation on glaciers of this region is given (F...

Recently we introduced a Sub-THz spectroscopic system for characterizing vibrational resonance features from biological materials. This new, continuous-wave, frequency-domain spectroscopic sensor operates at room temperature between 315 and 480 GHz with spectral resolution of at least 1 GHz and utilizes the source and detector components from Virgi...

Radiation in the Terahertz frequency range interacts with vibrations in the weakest molecular couplings such as hydrogen bonding, van der Waals forces, and hydrophobic interactions. The work presented demonstrates our efforts towards the development of a microfluidic device as the sample cell for presenting liquid samples within the detection regio...

Sub-terahertz (sub-THz) vibrational spectroscopy for biosensing is based on specific resonance features, vibrational modes or group of modes at close frequencies, in the absorption (transmission) spectra of large biological molecules and entire bacterial cells/spores. Further improvements in sensitivity, especially in the discriminative capability...

We will present result of combined experimental and computational study of sub-THz absorption spectra from Escherichia coli (E.coli) DNA. Measurements were conducted using a Bruker FTIR spectrometer with a liquid helium cooled bolometer and a recently developed frequency domain sensor operating at room temperature, with spectral resolution of 0.25...

The four-way DNA junction that is a structural building block for DNA self-assemblies has been widely studied by diffraction methods and other physical techniques. However, terahertz (THz) spectroscopic characterization, which can reveal specific absorption fingerprints from different DNA structures and sequences, has not been reported yet. In this...

Analysis of current and historical data demonstrates that the cryosphere component are very sensitive to the climate change thus proving its role as the climate indicator. In the process of this a pattern of the changes clearly reflect regional climate characteristics. International cryospheric community works very hard for efficient organization o...

This paper examines changes in the surface area of glaciers in the North and South Chuya Ridges, Altai Mountains in 1952-2004 and their links with regional climatic variations. The glacier surface areas for 2004 were derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery. Data from the World Glacier Inventor...

As part of a broad study to survey and parse the fundamental spectroscopic features of double stranded DNA in the THz domain, we have performed a comparative study of a 2900 bp basic sequence, 3200 bp basic sequence with inserts, and segments of the basic sequence of 1000 and 500 bp over the range 10-25 cm^-1. Samples were generated by am...

We investigated resonance spectroscopic features from several widely used explosives materials including RDX and PETN in the low THz range with the goal of understanding the mechanism of interaction between radiation and material in the form of solid films, gels and dilute solutions (suspensions). FTIR spectroscopy was used to measure spectra in tr...

Biological macromolecules such as DNA, proteins, and polysaccharides often display unique absorptive signatures in the THz region, useful in their identification and imaging through Raman and Fourier transform transmission spectroscopy. The optoelectronic properties of nanostructure-DNA complexes immobilized on transparent, semi-rigid substrates su...

Two conformations of the retinal molecule have been studied in order to characterize the molecule's THz transmission spectra in both the ground and metastable states. When subjected to an adequate external excitation the retinal molecule can experience a change in conformation and associated THz transmission spectra. In an attempt to accomplish thi...

The experimental and computational study of bacterial thioredoxin, an E. coli protein, at THz frequencies is presented. The absorption spectrum of the entire protein in water was studied numerically in the terahertz range (0.1 – 2 THz). In our work, the initial X-ray molecular structure of thioredoxin was optimized using the molecular dynamical (MD...

The molecular structure of the entire transfer RNA (tRNA) molecule of E. coli was simulated and the associated THz vibrational spectra was derived theoretically. The molecular structure was optimized using the potential energy minimization and molecular dynamical (MD) simulations. Solvation effects (water molecules) were also included explicitly in...

In this work we present the results on combined experimental and computational study of sub-THz spectra of liquid water. The important new result is the detection of hydrogen bonds in liquid water. The experimental study was performed by employing Fourier Transform terahertz (THz) spectroscopy with spectral resolution of 0.25 cm-1. Resonance featur...

The development of an effective biological (bio) agent detection capability based upon terahertz (THz) frequency absorption spectra will require insight into how the constituent cellular components contribute to the overall THz signature. In this work, the specific contribution of ribonucleic acid (RNA) to THz spectra is analyzed in detail. Previou...

A summary is provided for terahertz attenuation signatures measured in spore-laden samples of Bacillus subtilis in three different forms: 1) concentrated powder; 2) dilute powder; and 3) aerosol. In addition to a surprising spectral narrowness, some signatures also display an increase in peak signature strength (per spore) with dilution of the samp...

Significant progress has been achieved during the last several years relating to experimental and theoretical aspects of terahertz (or submillimetre wave) Fourier transform spectroscopy of biological macromolecules. However, previous research in this spectral range has been focused on bio-materials in solid state since it was common opinion that hi...

This paper reports on the THz frequency characterization of highly diluted mixtures of Bacillus Subtilis (BG) cells and spores pressed into pellets with high densities of polyethylene (PE) micro-powders. This technique of forming matrices of sparsely distributed biological (bio) materials by mixing them into larger concentrations of PE is one that...

Only few studies have attempted to characterize biological materials by THz spectroscopy. Most of these used either solid samples or biological tissues. In this work, we present results of THz spectroscopic characterization of dilute solutions of DNA samples. Water and heavy water (D2O) have strong absorbance that overlap significantly with importa...

Only few studies have attempted to characterize biological materials by THz spectroscopy. Most of these used either solid samples or biological tissues. In this work, we present results of THz spectroscopic characterization of dilute solutions of DNA samples. Water and heavy water (D2O) have strong absorbance that overlap significantly with importa...

The development of efficient biological agent detection techniques requires in-depth understanding of THz absorption spectral features of different cell components. Chromosomal DNA, RNAs, proteins, bacterial cell wall, proteinaceous coat might be essential for bacterial cells and spores THz signature. As a first step, the DNA's contribution into en...

In this work, results from parallel measurements of reflection and transmission spectra of biological molecules were utilized to enable detailed and direct calculation of the refractive index and absorption coefficient spectra in the Terahertz gap. The DNA samples from herring and salmon, as well as the protein Ovalbumin sample, have been character...

This work demonstrates application of Fourier Transform Infrared Spectroscopy (FTIR) technique in the low terahertz frequency range of 10-25 cm-1 to discriminate between different protein conformations and evaluate possible application of THz spectroscopy for monitoring of protein folding-unfolding process. A specific procedure developed earlier fo...

This work presents the first demonstration of the characterization of cancer cells using Fourier Transform Infrared Spectroscopy (FTIR) technique in the low terahertz frequency range of 10-25 cm-1 and shows how this technique can be used to discriminate between two types of cancer (prostate and bladder) in cell culture. Samples of cancer cells susp...

Terahertz Spectroscopy has been recently introduced as a promising technique for the collection of signature data in transmission spectra of biological materials including warfare agent simulants. To characterize material rather than sample, it is always desirable to obtain the material's optical properties as functions of frequency. In this work,...

This work presents spectroscopic characterization results for biological simulant materials measured in the terahertz gap. Signature data have been collected between 3 cm-1 and 10 cm-1 for toxin Ovalbumin, bacteria Erwinia herbicola, Bacillus Subtilis lyophilized cells and RNA MS2 phage, BioGene. Measurements were conducted on a modified Bruker FTI...

Significant progress has been achieved during the last several years relating to experimental and theoretical aspects of Terahertz (or Sub-millimeter wave) Fourier transform spectroscopy of biological macromolecules. Multiple resonance due to low frequency vibrational modes within biological macromolecules have been unambiguously demonstrated. Howe...

Significant progress has been achieved during the last several years relating to experimental and theoretical aspects of Terahertz (or Sub-millimeter wave) Fourier transform spectroscopy of biological macromolecules. Multiple resonance due to low frequency vibrational modes within biological macromolecules have been unambiguously demonstrated. Howe...

The terahertz frequency absorption spectraof DNA molecules reflect low-frequencyinternal helical vibrations involvingrigidly bound subgroups that are connectedby the weakest bonds, including thehydrogen bonds of the DNA base pairs,and/or non-bonded interactions. Althoughnumerous difficulties make the directidentification of terahertz phonon modes i...

Terahertz (THz) Fourier transform spectroscopy of biological materials demonstrate the existence of multiple species-specific low frequency resonance modes associated with weak bonds in molecules. Transmission measurement results are reported for synthetic polynucleotides with different but known base combination and sequences and for more complex...

The conformational transition collagen-like triple helix in equilibrium with chains of oligotripeptides Z-(Gly-Pro-Pro)n-OMe with n = 6, 7, 8 in water by variation of solution temperature and sample concentration has been studied using IR-, CD-spectroscopy and microcalorimetry methods. The straight line correlation between the obtained value of the...

The conformational transition collagen-like triple helix↔dissociated chains of ogotripeptides Z-(Gly-Pro-Pro)n-OMe with n=6,7,8 in water by variation of solution temperature and sample concentration has been studied using IR-, CD-spectroscopy and microcalorimetry methods. The straight line correlation between the obtained value of the transition en...

The ir amide bands of the triple-helical polytripeptides and collagens upon hydration of films are investigated. On the basis of our assignment of the amide I components, the formation of hydrogen bonds between the peptide backbone and structural water is studied. The C1O1--HOH hydrogen bonds are found more ordered than the C3O3--HOH hydrogen bonds...

By the IR-spectroscopy method successive stages of hydrate envelope formation of the collagen-like triple-helical structure of the monodisperse synthetic polytripeptide Z-(Gly-Pro-Pro)8-OMe were studied. The multistep-type process is followed by isomorphic transitions of the triple-helical structure and by the increasing of hydrogen bond strength.

As a result of investigating special glacial maps, the conclusion is made that accumulation conditions prevail over the ablation conditions in their impact on glacier distribution and dynamics of two regional glacial systems of the temperate climatic belt.

The authors have investigated the conformational transition of triple helix-unordered chains of a collagen-like polytripeptide Z-(glypropro)8-OMe by infrared and c.d. spectroscopy and microcalorimetry. It is shown that the transition is of a one-stage character. The value of the enthalpy of the transition found per mole tripeptide unit corresponds...

The infrared amide I band of collagens (rat and cod skin) and related compounds (polyproline, polyglycine, and polytripeptides) was studied. Assignment of amide I-band components for polyproline II and polytripeptides (Gly-Pro-Pro)n and (Gly-Pro-Gly)n in the solid state and water solution was made. Three amide I components observed in the polypepti...

Infrared spectra were measured for both aqueous (D2O) solution and the solid state of form II poly-L-proline in the amide I region as a function of the temperature. The temperature range includes the region where a precipitation is known to occur. From the analysis of spectra of hydrated films and aqueous solutions at different temperatures one can...