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Currently, the Kurchatov Laser−Synchrotron Complex is conducting research on the interaction of powerful femtosecond laser radiation with matter. The purpose of these studies is to develop new techniques and approaches for the characterization of high−temperature plasma, X−rays and particle acceleration, which can be the basis for the work planned within the framework of the synchrotron−neutron project. Laser−driven X−ray production, electron acceleration, nuclear fusion, ultrafast structural dynamics of nanoparticles in intense laser fields remains an active research topic, aimed at generating advanced controllable sources.

The results of studying the attitude of the population to the confidentiality of personal data on the Internet are presented. In empirical terms, this article is based on a representative survey of the Moscow population of May‒June 2020. It is recorded that the practice of presenting personal information when using various Internet services has become widespread. At the same time, two-thirds of the respondents expressed concerns about the security of personal information on the Internet. According to a binary regression model, the strongest predictors of this anxiety correlate with the prevailing privacy attitudes among respondents, practices of leaving personal information on the network (primarily about one’s children), negative assessments of security provision as a norm of life in a democratic society, and general dissatisfaction with the functioning of the political system.

The article considers the dynamics of the TV and Internet consumption of different cohorts under the dramatic changes in the Russian media landscape. In the last decade, the media environment has reached the mass scale in the use of the latest communication technologies based on the high-speed mobile Internet and its various apps. The results of the comparison of the studies of 2012 and 2017 indicate multidirectional trends: an increase in the average daily time of the Internet use in the middle-age and partly elder cohorts, and a moderate increase in the younger groups. The duration of TV viewing is a cyclic phenomenon determined by the stages of life cycle and socialization: the TV consumption of the same cohorts tends to decrease in a five-year interval. According to the theory of media substitution, the Internet is partly a functional alternative to TV for it allows the needs of the audience to be more fully satisfied and to develop on the basis of new technological opportunities. The article also considers features of the media consumption of the digital generation (millennials). This group is internally very different: it consists of several age and social-professional subgroups with serious differences in the average daily TV and Internet consumption. All these trends of the media consumption changed under the covid-19 crisis: changes in the mode of life and a fundamentally different information agenda determined an increase in the media use, primarily TV and the Internet. The long-term trend of the gradual decrease of the TV-audience changed: the average TV viewing increased in all cohorts. Under the crisis, the leading functions of the media - information and recreation - are more in demand than before.

The main reason for the alternation of terahertz (THz) response in biological samples is the transition of a part of water from its free to bound state and back. To analyze such results, a precise spectrum of bound water within THz range should be known. The suggested wet powder spectroscopy method is optimal for this task. We measured the THz transmission of dry glucose pressed into pellets. Then, we added a small amount of water to these pellets and again measured the THz spectra. The contribution from the free water state starts to appear in resulting THz spectra after water concentration in glucose samples reaches 14–16%. Just below is the optimal point to extract the spectral contribution from bound water. We extracted the absorption and refraction spectra of bound water and confirmed that they are an order of magnitude weaker than those of free water within 0.07–1-THz range.

Media is one of the most important social institutions that mediates the attitude of citizens to other institutions of society. Thus, one of the key features of the contemporary society is the trust of citizens in basic social institutions. The article considers the issue of public trust in the Russian media and focuses on the question to what extent the trust of Russian citizens in the mass media depends on the trust in other state and public institutions. The authors’ conclusions are based on the comparative empirical studies in the metropolitan region conducted in 2016-2018. The data show that people do not really trust in media: about a half of respondents do not trust this institution. This is a common trend for the post-Soviet period in general. The authors used binary logistic regression, and found out that distrust in media is significantly correlated with distrust in other institutions such as the president, State Duma, law enforcement agencies, political parties, church, banks and businesses. Moreover, according to the statistical model, the lack of trust in media is determined by social-economic problems, general dissatisfaction with political system, and negative attitudes to media content and its role in the society. When studying trust in media one should take into account the ongoing transformations of media landscape: today the most trusted media are Internet and television (practically the same level of trust). There is also a clear age differentiation: trust in media generally grows with age, although the situation is opposite considering trust in the Internet. The development of media technologies and online services and networks makes it increasingly difficult to assess the level of public trust in media and other institutions.

The status and dynamics of religiosity in modern Russia are considered. The distinctive features of religious consciousness and behavior have been fixed proceeding from the system of indexes and empirical indicators developed. In the course of comparative representative studies, which have been accomplished in the metropolitan area over the last three decades on the basis of a single methodology, it has been fixed that, at the level of self-identification, approximately half of the population define themselves as believers, this value decreasing over time. The use of the complex typology of religiosity shows that the share of church believers proper, who observe the canons at the level of both consciousness and behavior, is substantially smaller: in the last five years, it has been within 6–8%. The motives to participate in religious rites are predominantly of a general cultural character, determined by family, relational, and national traditions.

Early diagnosis of glioma may be achieved by detecting the molecular biomarkers in brain tissues and body fluids. Terahertz (THz) and infrared (IR) absorption spectra of mouse blood plasma were studied in the dynamics of the U87 glioblastoma development. Machine learning methods were used to identify the most informative THz and IR spectral ranges associated with glioma molecular markers provided the best distinguishing animals with and without glioblastoma.

Significance: The creation of fundamentally new approaches to storing various biomaterial and estimation parameters, without irreversible loss of any biomaterial, is a pressing challenge in clinical practice. We present a technology for studying samples of diabetic and non-diabetic human blood plasma in the terahertz (THz) frequency range. Aim: The main idea of our study is to propose a method for diagnosis and storing the samples of diabetic and non-diabetic human blood plasma and to study these samples in the THz frequency range. Approach: Venous blood from patients with type 2 diabetes mellitus and conditionally healthy participants was collected. To limit the impact of water in the THz spectra, lyophilization of liquid samples and their pressing into a pellet were performed. These pellets were analyzed using THz time-domain spectroscopy. The differentiation between the THz spectral data was conducted using multivariate statistics to classify non-diabetic and diabetic groups’ spectra. Results: We present the density-normalized absorption and refractive index for diabetic and non-diabetic pellets in the range 0.2 to 1.4 THz. Over the entire THz frequency range, the normalized index of refraction of diabetes pellets exceeds this indicator of non-diabetic pellet on average by 9% to 12%. The non-diabetic and diabetic groups of the THz spectra are spatially separated in the principal component space. Conclusion: We illustrate the potential ability in clinical medicine to construct a predictive rule by supervised learning algorithms after collecting enough experimental data.

This work describes the promising approach for the diagnostic of diseases, such as diabetes, by using the THz spectroscopy and THz holography method. In this paper, dry pellets consisting of human blood plasma (normal and diabetic) were designed; these objects were analyzed in various THz Russian laboratories, PCA-analysis of THz spectra was applied to separate the normal and diabetic groups; the holographic approach was proposed that provides sufficient information to reconstruct the spatial distribution of complex refractive index of the samples.

2-TW, 30-fs, 800-nm laser radiation and its second harmonic are used to form a filament in low pressure gas cell. This filament forms a bright source of terahertz pulses. For 1-20 mbar gas pressure we registered a hundred-fold increase of THz yield compared with ambient air conditions. The dynamics of local intensity in the filament was measured by filament foil ablation and X-ray generation techniques.

The dependence of the THz transmission spectra of bovine serum albumin (BSA) solution on the temperature is experimentally studied. The differences between BSA solutions absorption with concentrations from 0 to 500 mg/ml with a change in their temperature (from 20 to 80°C) are analyzed. With increasing protein concentration, the transmission amplitude increases, and with increasing solution temperature — it decreases.

The article presents the results of the comparative study of political-ideological views of the Russian population on the values of freedom, democracy, social justice, the role of the state, etc. The research covers almost a quarter of a century - the surveys based on the same questionnaire were conducted among Muscovites in 1992 and 2016. The results of the comparative study show that the structure of the views on basic political values has not changed significantly. However, there are still different, often opposite social-political representations in the Russian society, which is clearly manifested when opposing freedom and inequality, democracy and socialism, social justice and individualism. Moreover, the shares of respondents expressing opposite views are approximately equal. At the same time, the attitudes structure revealed at the end of the last century has changed if compared to the data of 2016 survey, especially considering the role of individual activities in determining life trajectories. There is growing support for the importance of individualism as opposed to social justice and for the expectations of various types of state social guarantees. The results of the multidimensional statistical classification prove that there are several groups with different political-ideological orientations - from supporters of liberal democratic ideas to those who prefer socialist values. However, most groups still support the paternalistic ideas of the Soviet period such as the importance of social guarantees and social role of the state.

We demonstrate a multicompartment, power-scalable beam-line design in which sub-40-fs, terawatt field waveforms are tailored in space and time for downstream pulse compression to few-cycle pulse widths attained right at the site where the intense laser field interacts with a target. An accurate field-waveform characterization performed at multiple locations along the beam path shows that, despite all the complexity of their upstream nonlinear electrodynamics, field waveforms shorter than three field cycles can be delivered to a laser–matter interaction site in such a system, enabling a vast class of ultrafast strong-field laser–matter interaction studies.

The key characteristics of the social situation in their interconnection with the population’s orientations to various forms of protest activity are considered. The empirical base of this paper is the data of the comparative representative studies conducted in Moscow in 2008–2016. Analysis of these data has made it possible to fix negative trends in the development of the social feeling of citizens in recent years. The authors characterize the dynamics of social tension and citizens’ attitude to various forms of defending their interests. The use of binary logistic regression makes it possible to build a hierarchy of the social situation’s factors that demonstrate the probability of active participation in protest. Such factors include negative phenomena of social life, a critical attitude to the existing political system, and adoption of orientations at participating in a conflict on the side of one’s ethnic group. Consideration of the above factors in the practice of social management can minimize the potential of social tension.

Ultrafast ionization of a gas medium driven by ultrashort midinfrared laser pulses provides a source of bright ultrabroadband radiation whose spectrum spans across the entire microwave band, reaching for the sub-gigahertz range. We combine multiple, mutually complementary detection techniques to provide an accurate polarization-resolved characterization of this broadband output as a function of the gas pressure. At low gas pressures, the lowest-frequency part of this output is found to exhibit a drastic enhancement as this field builds up its coherence, developing a well-resolved emission cone, dominated by a radial radiation energy flux. This behavior of the intensity, coherence, and polarization of the microwave output is shown to be consistent with Cherenkov-type radiation by ponderomotively driven plasma currents.

We discovered that intensity of ∼1016 W/cm2 and 20 mJ energy in femtosecond laser pulse is enough to observe THz emission from the rear side of metal foil in a vacuum. In the same experiment for 2-10 mbar air pressure and two-color pump similar energy of THz pulse form gas plasma was detected. Comparable amplitude and spectra of THz emission are also observed in reflection from the metal foil front side. X-ray emission is also studied as a criterion of intensity optimization. For much lower (1014 W/cm2) intensity reflected THz emission was detected as a result of optical rectification in a thin metal film with 10−6 efficiency. While for sub-relativistic intensities the observed efficiency 10−5 of THz generation from metal is higher than predicted by known theories. The main benefit of THz generation in metal is the absence of yield saturation at TW level of laser energy and above.

Intense electromagnetic fields can be obtained now in THz frequency range. THz pulses with electric field intensity above 1 MV/cm are now requested for strong-field applications like particle acceleration, short electron bunches measurements, controlling the state of the matter. The advantage of a THz pulse in comparison with the visible frequency range is the almost non-oscillating field that interacts with charged particles more efficiently. The advantage over a direct field is the ability to remotely focus this radiation in space and in time. Except for the huge free-electron lasers facilities, the only way to get THz pulses of MV/cm intensity is the conversion of high-power femtosecond laser pulses. We compare two ways of generating intense THz pulses using the radiation of TW and GW laser systems operating at 800 nm. They are two-color filamentation in gas and optical rectification in nonlinear crystals. The prospects for scaling of THz generation methods for a petawatt laser are discussed.

Terahertz time-domain spectroscopy (THz-TDS) in the 0.05–1.0 THz frequency range was used to study the blood serum of rats in the dynamics of experimental liver cancer. It was shown that the THz transmission spectra of samples from healthy animals and 14 and 28 days after tumor cells implantation are similar in shape, but differ in amplitude. There is a change in the biochemical composition of the blood, including a decrease in the protein content, by the 28th day of the experiment. The observed changes in the THz response are explained by a decrease in the number of protein molecules and bound water and correlate with changes in the refractive index in the visible and near-IR ranges from 480 to 1550 nm, measured using a multiwave refractometer.

We study experimentally the absorption and refraction spectra for a number of amino acids, proteins and nucleic acids in the frequency range 0.1–3.5 THz. The characteristic absorption lines are revealed. The spectroscopy of water solutions of proteins and nucleic acids is carried out under conditions of total internal refraction. This method can be used for studies of the functional properties of biomolecules and the dynamics of their interaction.

The generation of terahertz (THz) pulses by the optical rectification of femtosecond laser pulses in a ZnTe crystal is studied. A substantial decrease in the THz radiation power was observed upon tight focusing of laser radiation into the crystal. It is shown that the consideration of competing two-photon absorption and second-harmonic generation processes proceeding simultaneously with optical rectification cannot explain this effect even qualitatively. It is assumed that the observed decrease in the THz radiation power is caused by a decrease in the size of a source of nonlinear polarisation. The conditions are found for the most efficient generation of THz radiation in the ZnTe crystal.

The terahertz time-domain and Raman spectra of steroids in the region of 0.1-3.5 THz have been measured. Steroids have several intense and specific absorption features in the THz frequency region. The features are uniquely determined by a hormone structure. This allows us to analyze steroids in complex samples such as pharmaceuticals, foodstuffs and biological fluids, and in process of the pharmacological and chemical synthesis.

The object of this investigation is the political consciousness of the population in mid-1992. We have attempted to determine attitudes to basic sociopolitical values under conditions of a deepening systemic crisis, as well as to ascertain the level of support for the most influential political forces during the period of the investigation. We should stipulate from the outset that the ethnonational components of ideological conceptions remained outside the framework of the study.

The THz and Raman spectra of progesterone, 17a-hydroxyprogesterone and cortisone in the region of low-frequency infrared vibrations have been measured. Several intensive bands have unusual temperature dependence. Vibration frequencies are calculated by density functional theory.

The theory of guided waves in metal-dielectric planar multilayer structures is applied to reduce the loss and maximize optical nonlinearity for efficient terahertz-field generation in a surface electromagnetic wave by femtosecond laser pulses confined in a (chi)((2)) nonlinear planar waveguide. For typical parameters of thin-film polymer waveguides and metal-dielectric interfaces, the optimal size of the (chi)((2)) waveguide core providing the maximum efficiency of terahertz plasmon-field generation is shown to be less than the wavelength of the optical pump field.

A diffraction grating engraved in a limited area of a flat aluminum surface serves as coupler to excite surface plasmon that propagates along the flat surface. At the flat surface edge, THz radiation is scattered into free space and impinges the edge of a similar antenna, on which a surface plasmon is excited and diffracted by a grating towards a detector. Using THz time-domain spectroscopy, we study the plasmon-plasmon coupling. We report a strong coupling efficiency over several cm of propagation in air.

Chiral molecules have no plane of symmetry and occur as right- or left-handed enantiomers. Although these molecules play an essential role in chemistry and especially in biology, their physics has not been much studied until quite recently. For that purpose highly sensitive reliable informative methods for detection and quantitative analysis of chirality in molecular structure are needed.

A new technique for investigating the surface plasmons by means of a scanning acoustic microscope is proposed. Within this technique, the surface electromagnetic wave (plasmon polariton) is excited by laser radiation on one side of a metal film, while a scanning acoustic microscope excites surface acoustic waves on the other side of the film. Obtained for the first time, the acoustic images of plasmons, propagating on the grating surface, demonstrate the possibility of studying the plasmon wave field distribution by means of a scanning acoustic microscope.