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Recently, nanodiamonds with negatively charged luminescent color centers based on atoms of the fourth group (SiV−, GeV−) have been proposed for use as biocompatible luminescent markers. Further improvement of the functionality of such systems by expanding the frequencies of the emission can be achieved by the additional formation of luminescent tungsten complexes in the diamond matrix. This paper reports the creation of diamond matrices by a hot filament chemical vapor deposition method, containing combinations of luminescing Si-V and Ge-V color centers and tungsten complexes. The possibility is demonstrated of creating a multicolor light source combining the luminescence of all embedded emitters. The emission properties of tungsten complexes and Si-V and Ge-V color centers in the diamond matrices were investigated, as well as differences in their luminescent properties and electron-phonon interaction at different temperatures.

The investigation of the hot filament chemical vapor deposition nanodiamonds with simultaneously embedded luminescent GeV− and SiV− color centers from solid sources showed that both the absolute and relative intensities of their zero-phonon lines (at 602 and 738 nm) depend on nanodiamond growth conditions (a methane concentration in the CH4/H2 gas mixture, growth temperature, and time). It is shown that a controlled choice of parameters of hot filament chemical vapor deposition synthesis makes it possible to select the optimal synthesis conditions for tailoring bicolor fluorescence nanodiamond labels for imaging biological systems.

The purpose of this research was to study the quality of life of patients on hemodialysis. At the same time, both own data and data from literary sources and electronic resources were used. Quality of life assessment is an important element of health assessment and helps to suggest appropriate measures that need to be taken to improve the quality of life of patients with end-stage renal failure. Own data were collected in one of the hemodialysis centers of Tambov in 2020. To assess the quality of life, we have adapted the assessment questionnaire WHOQOL-BREF (short form WHO-100), which is used worldwide. It included information on socio-demographic characteristics, the main diagnosis, concomitant diseases, the type of vascular access, the duration of hemodialysis, and the serological status of hepatitis. Patients ( n = 138) were divided into 3 subgroups according to the duration of dialysis: 1 year, 2 years, and 3 years. The socio-economic status of the participating patients was divided into categories of upper, middle, and low socio-economic status, depending on income, level of education, and type of employment. The results of this research indicate that the quality of life of patients on hemodialysis is significantly reduced. Such determinants as age, longer duration of dialysis, diabetes, and hypertension, central venous catheter as vascular access for dialysis, lower socio-economic status and a positive result of a serological study of hepatitis are all statistically significant factors that negatively affect the quality of life. Some of these factors can be controlled, leveled, or compensated for. Therefore, in order to improve the quality of life of hemodialysis patients, it is necessary to strive for better control of diabetes and hypertension, encourage the use of an AV fistula rather than a central catheter, and improve infection control for hepatitis viruses.

The optical properties of chemically synthesized carbon dots (CDs) can be widely tuned via doping and surface modification with heteroatoms such as nitrogen, which results in a range of potential applications. Herein, two most commonly used synthesis approaches, namely, solvothermal and microwave-assisted thermal treatments, have been used for the preparation of CDs from phloroglucinol using three different nitrogen containing solvents, namely, ethylenediamine, dimethylformamide, and formamide. Based on the analysis of the morphology and optical properties, we demonstrate the tenability of the CD appearance from amorphous or well-carbonized spherical particles to onion-like ones, which is controlled by solvent polarity, whereas the thermal treatment conditions mostly influence the degree of N-doping and the nature of emissive centers of CDs formed. The findings of this study expand the toolkit of the available CDs with variable morphology and energy structure.

We consider the main conceptual basic principles of the theory of assessing the quality of life (QoL) and the quality of life associated with health (HRQoL). We reveal the essence and socio-economic significance of the concept of “quality of life”, its semantic and operational fullness. We present the analysis of the essence of the “health-related quality of life” concept, its significance for evaluating the effectiveness of the therapeutic and diagnostic process, important aspects of the use of HRQoL tools in real clinical conditions, differences and orientation of non-specific and specific questionnaires used in medicine. It is noted that measuring the quality of life is an important component of interviewing a patient, involving him in treatment, making decisions about medical interventions and limiting the possibilities of modern medicine by suspending or stopping treatment, so as not to prolong life at any cost, but to improve subjective perceptions during the remaining life span. Making the quality of life measurable is a methodological task, since it cannot be directly displayed; the development of objective and subjective indicators is indicative here, but they should also be sensitive enough to changes to correctly assess the quality of life. At the same time, the development of questionnaires for measuring the quality of life is subject to quality assurance criteria that must be met in the research process. In conclusion, an example of comprehensive studies of the quality of life conducted at the Public Health and Healthcare Department of Medical Institute in Derzhavin Tambov State University, where a regional center for the study of the quality of life of various population groups, as well as the quality of life of patients suffering from various diseases, has been successfully operating in the last few years.

The purpose of this review was to generalize and systematize the methodological and organizational approaches that have developed at present in diagnosis and treatment of acute pancreatitis. We conducted a systematic search on Ovid MEDLINE (http://www.ovid.com/site/catalog/ DataBase/901.jsp), EMBASE (http://www.embase.com/), CINAHL (http://www.ebscohost.com/ cinahl/), Web of Science (www.isiknowledge.com/), ETOH (http://etoh.niaaa.nih.gov/) and AIM (http://www.aim-digest.com/gateway/m%20index.htm) to research epidemiological studies conducted in foreign countries and published from January 2008 to January 2018, which considered current issues of treatment and diagnostic organization for acute pancreatitis. The search was carried out using any combination of keywords: acute pancreatitis, organization, therapeutic and diagnostic process, severity assessment, methodological approaches, severity classifications, evaluation scales. In addition, we manually reviewed the content pages of the main epidemiological journals and lists of links to relevant publications in review articles. A database of 142 units from literary and information sources was created. The final analysis included 52 sources that reflect the methodological aspects of the treatment and diagnostic process for acute pancreatitis.

The charge density wave (CDW) phase transition between the nearly commensurate (NCCDW) and incommensurate (ICCDW) phases in 1T-TaS2 around 350 K was investigated by electrical resistance measuremen...

The photostability of the luminescent properties of CuInS2/ZnS quantum dots (CIS/ZnS QDs) as a monolayer on a dielectric substrate and as part of a hybrid structure with multilayer graphene nanoribbons (ML GNRs) has been studied. Analysis of the luminescence kinetics of quantum dots has revealed the presence of three main components of luminescence attenuation, characterized by times of the order of 20, 100, and 300 ns. It has been shown that the efficiency of the interaction between CIS/ZnS quantum dots and multilayer graphene nanoribbons has a dependence on the number of graphene monolayers similar to that of CdSe quantum dots. The photostability of CIS/ZnS QDs on a dielectric substrate and in structures with multilayer graphene nanoribbons has been estimated, which allowed us to estimate the energy/charge transfer rates from QDs to multilayer graphene nanoribbons as 106–107 s–1.

Relatively weak red photoluminescence of carbon dots (CDots) is a major challenge on the way to their successful implementation in biological and optoelectronic devices. We present a theoretical analysis of the interaction among the surface emission centers of CDots, showing that it may determine efficiency of the red photoluminescence of CDots. Based on the previous experimental studies, it is assumed that the optical response of the CDots is determined by the molecule-like subunits of polycyclic aromatic hydrocarbons (PAHs) attached to the CDots' surface. Three characteristic types of coupling of these PAH subunits are considered: non-interacting monomers, noncovalently bound dimers, and covalently bound dimers with two, three, or four carbon linkers. We demonstrate that the CDots' photoluminescence broadens, redshifts, and weakens by 2 orders of magnitude when the free monomers are substituted by the covalently bridged centers. These and other results of our study show that the realization of CDots with many weakly interacting surface emission centers may constitute an efficient way to achieve their efficient red photoluminescence, which is highly desirable for biological and optoelectronic applications.

The impact of irradiation with higher and lower quantum energy than that corresponding to the fundamental absorption band of CdSe nanoplatelets has been studied. We show that the irradiation wavelength and oxygen strongly influence the photoluminescence of nanoplatelets. We demonstrate also that irradiation of CdSe nanoplatelets dry layers leads to a reversible change in their photoluminescence quantum yield.

Here, we report an investigation of optical activity which was photochemically induced by illumination of QRs and DiRs with circularly polarized light; the photo-induced circular dichroism was quantitatively estimated, and it was shown that the photo-induced chemical reaction proceeds selectively, depending on the handedness of circularly polarized light.

The effects of a high background count and a microsecond dead time interval on a gated InGaAs/InP single-photon avalanche photodiode (SPAD) during microsecond luminescence decay registration are discussed. It is shown that the background count rate of the SPAD limits its use for time-resolved and steady-spectral measurements, and that a “pile-up” effect appears in the microsecond range.

We synthesized diamond particles with germanium-vacancy color centers on a germanium substrate by hot-filament chemical vapor deposition. The formation of color centers occurred during the growth of diamond particles by the introduction of germanium atoms formed by the etching of a crystalline germanium wafer with atomic hydrogen. The conditions of the vapor phase deposition, which affect the photoluminescence of germanium-vacancy color centers in diamond particles, are considered. The highest photoluminescence intensity of germanium-vacancy color centers was achieved for diamond particles obtained on a substrate at a temperature of its surface close to the melting point of germanium. In the photoluminescence spectra of diamond particles, we also observed the lines presumably related to optical centers including tu-ngsten.

Carbon dots (CDs) are light-emitting nanoparticles that show great promise for applications in biology and medicine due to the ease of fabrication, biocompatibility, and attractive optical properties. Optical chirality, on the other hand, is an intrinsic feature inherent in many objects in nature, and it can play an important role in the formation of artificial complexes based on CDs that are implemented for enantiomer recognition, site-specific bonding, etc. We employed a one-step hydrothermal synthesis to produce chiral CDs from the commonly used precursors citric acid and ethylenediamine together with a set of different chiral precursors, namely, L-isomers of cysteine, glutathione, phenylglycine, and tryptophan. The resulting CDs consisted of O,N-doped (and also S-doped, in some cases) carbonized cores with surfaces rich in amide and hydroxyl groups; they exhibited high photoluminescence quantum yields reaching 57%, chiral optical signals in the UV and visible spectral regions, and two-photon absorption. Chiral signals of CDs were rather complex and originated from a combination of the chiral precursors attached to the CD surface, hybridization of lower-energy levels of chiral chromophores formed within CDs, and intrinsic chirality of the CD cores. Using DFT analysis, we showed how incorporation of the chiral precursors at the optical centers induced a strong response in their circular dichroism spectra. The optical characteristics of these CDs, which can easily be dispersed in solvents of different polarities, remained stable during pH changes in the environment and after UV exposure for more than 400 min, which opens a wide range of bio-applications.

The method of hot-filament chemical vapor deposition has been employed to synthesize diamond particles with germanium–vacancy and silicon–vacancy color centers. In the next stage, the reactive ion-plasma etching of the particles was performed. This, yielded diamond nanoparticles with photoluminescence spectra constituted by two narrow high-intensity zero-phonon lines of the centers introduced. These fluorescent diamond nanoparticles are promising for application as sources of double-wave narrow-band emission in luminescent nanothermometry.

We understand the medical and demographic situation as a set of demographic phenomena and processes that are factors that negatively affect the state of health of the population in this territory, and actualize the need for making scientifically sound management decisions in the regional health system. The purpose of the study: on the basis of official statistics, to research the features of the demographic situation in the Tambov Region and to identify fundamental demographically determined patterns of formation, the state of health of the region's population. Materials and methods. As an information base, we used the following: official statistics on the demography of Tambovstat for 2000–2020; data from statistical collections of the Ministry of Health of the Russian Federation for 2007–2019. Results. The demographic situation in the region has been in deep crisis over the past decades and is characterized by a steady downward trend in the total population, averaging 10276 per year; lack of female population of fertile age, which is 41,4 % of all women instead of the necessary 50 %; adverse changes in the structure of women of fertile age, which consisted in a decrease in the proportion of intervals of 20–24 years and 25–29 years, which are the most reproductive; the low level of the total fertility rate, according to which the Tambov Region occupies 84th place among 85 subjects of the Russian Federation; completion of the formation of a low-density family model; 90 % of families in the Tambov Region have 1–2 children and only 10 % – more than two; sustainable narrowing of the population; in 2018, the average number of children a woman gives birth to during the re-productive period was 1.33 (TFR); negative natural growth and negative migration balances, which represent steady trends since 1990. In the Tambov Region, it is necessary to conduct fundamental demographic studies that will make it possible to develop scientifically justified models of the reproduction of the population of a typical agro-industrial region of the Central Federal District of the Russian Federation, calculate the forecast and offer management structures recommendations for the formation of a rational and productive regional demographic policy.

Formation of a non-emissive wide bandgap CsPb2Br5 component often accompanies the synthesis of CsPbBr3 perovskites, introducing undesired energy states and impeding the charge transport. Here, we demonstrate that a small amount of a methanol additive can promote the CsBr release rate, facilitating CsPbBr3 formation and suppressing CsPb2Br5 formation. Some of the methanol ionizes into CH5O+ and CH3O−, which act as surface ligands and change the crystallization environment, inducing shape evolution from spherical nanocrystals to rectangular nanoplatelets (NPLs), leading to monodispersed and phase-pure 8 unit-cell-thick CsPbBr3 NPLs. Meanwhile, nonradiative recombination processes are inhibited as a result of NPL surface passivation. Bright CsPbBr3 NPLs with a photoluminescence quantum yield reaching 90% were employed as emitters for electroluminescent light-emitting devices.

In the therapeutic practice of a therapist, patients in post-cholecystectomy syndrome or “Oddy sphincter dysfunction” are quite common. To rationally build the therapeutic and diagnostic process the gastroenterologist needs to know the “surgical background” of the patient. The peculiarities of surgery can also be of significant importance for the quality of life of patients with post-cholecystectomy syndrome. Patients' quality of life is a relevant topic in patient care after surgery, as well as in medical practice in general. This review analyses the concept of quality of life associated with the health of patients after cholecystectomy. We outlined state-of-the-art health-related ideas of Western researchers about quality of life, as well as methods for assessing it and the results of applying different methodological approaches among patients after cholecystectomy. We presented the results of analysis of 34 literary and informational foreign sources. We searched literature using the Medline database. We showed significance of assessment of patients' quality of life after cholecystectomy as an indicator of treatment effectiveness. We made a comparison of quality of life indicators after an open intervention and laparoscopic cholecystectomy and noted the advantages of the latter.

In this work, we present a comprehensive theoretical modelling of a chiral dimer made of two perovskite quantum dots (QDs). Taking into account the bright triplet exciton of QDs, we calculate the energies of the dimer’s quantum states and analyze the dependence of these energies on the dimer geometry. We also compute the circular dichroism (CD) spectra of the dimer and establish the optimal dimer parameters for maximizing its CD response. Our results show that the perovskite QD dimers feature a strong and tunable chiroptical response, making these superstructures attractive for chiral application.

Materials with perovskite-type crystal structure attract much attention due to their unique optical properties, such as high quantum yield of photoluminescence and high carrier mobility. However, their further utilization as an active media in photonic and optoelectronic devices is limited by the lack of stability of their optical responses together with the presence of lead cations in the chemical composition. Here, a detailed study of the optical properties and their stability under ambient conditions of perovskite films with the chemical composition (CH3NH3)xAyIz, where A = Pb, Bi, Sb, was performed. The changes in optical responses of the samples were monitored for 3 months. It was shown that the stability of perovskite films was improved by surface passivation with a thin layer of polymethylmethacrylate onto their surface. The developed procedures of film formation and following surface passivation are of interest in the design of active optical materials based on perovskite films with the increased optical performance.

The efficient and sensitive detection of pathogenic microorganisms in aqueous environments, such as water used in medical applications, drinking water, and cooling water of industrial plants, requires simple and fast methods suitable for multiplexed detection such as flow cytometry (FCM) with optically encoded carrier beads. For this purpose, we combine fluorescent Cd-free Ag-In-S ternary quantum dots (t-QDs) with fluorescence lifetimes (LTs) of several hundred nanoseconds and superparamagnetic Fe3O4 nanoparticles (SPIONs) with mesoporous CaCO3 microbeads to a magneto-fluorescent bead platform that can be surface-functionalized with bioligands, such as antibodies. This inorganic bead platform enables immuno-magnetic separation, target enrichment, and target quantification with optical readout. The beads can be detected with steady-state and time-resolved fluorescence microscopy and flow cytometry (FCM). Moreover, they are suited for readout by time gated emission. In the following, the preparation of these magneto-fluorescent CaCO3 beads, their spectroscopic and analytic characterization, and their conjugation with bacteria-specific antibodies are presented as well as proof-of-concept measurements with Legionella pneumophila including cell cultivation and plating experiments for bacteria quantification. Additionally, the possibility to discriminate between the long-lived emission of the LT-encoded capture and carrier CaCO3 beads and the short-lived emission of the dye-stained bacteria with time-resolved fluorescence techniques and single wavelength excitation is demonstrated.

Carbon dots (CDots) are a promising biocompatible nanoscale source of light, yet the origin of their emission remains under debate. Here, we show that all the distinctive optical properties of CDots, including the giant Stokes shift of photoluminescence and the strong dependence of emission color on excitation wavelength, can be explained by the linear optical response of the partially sp2-hybridized carbon domains located on the surface of the CDots' sp3-hybridized amorphous cores. Using a simple quantum chemical approach, we show that the domain hybridization factor determines the localization of electrons and the electronic bandgap inside the domains and analyze how the distribution of this factor affects the emission properties of CDots. Our calculation data fully agree with the experimental optical properties of CDots, confirming the overall theoretical picture underlying the model. It is also demonstrated that fabrication of CDots with large hybridization factors of carbon domains shifts their emission to the red side of the visible spectrum, without a need to modify the size or shape of the CDots. Our theoretical model provides a useful tool for experimentalists and may lead to extending the applications of CDots in biophysics, optoelectronics, and photovoltaics.

Development of chiral quantum dots (QDs) is an emerging field, as these nanomaterials could find a range of potential applications including sensing, imaging, asymmetric catalysis, enantiomeric sep...

Nanocrystals of AgInS2 demonstrate giant Stokes shifts ∼1 eV, the nature of which is still not clearly understood. We propose a theoretical model of this phenomenon, bringing together several diffe...

Cd-free I-III-VI group semiconductor quantum dots (QDs) like Ag-In-S and Cu-In-S show unstructured absorption spectra with a pronounced Urbach tail, rendering the determination of their band gap energy (Eg) and the energy structure of the exciton difficult. Additionally, the origin of the broad photoluminescence (PL) band with lifetimes of several hundred nanoseconds is still debated. This encouraged us to study the excitation energy dependence (EED) of the PL maxima, PL spectral band widths, quantum yields (QYs), and decay kinetics of AIS/ZnS QDs of different size, composition, and surface capping ligands. These results were then correlated with the second derivatives of the corresponding absorption spectra. The excellent match between the onset of changes in PL band position and spectral width with the minima found for the second derivatives of the absorption spectra underlines the potential of the EED approach for deriving Eg values of these ternary QDs from PL data. The PL QY is, however, independent of excitation energy in the energy range studied. From the EED of the PL features of the AIS/ZnS QDs we could also derive a mechanism of the formation of the low-energy electronic structure. This was additionally confirmed by a comparison of the EED of PL data of as-synthesized and size-selected QD ensembles and the comparison of these PL data with PL spectra of single QDs. These results indicate a strong contribution of intrinsic inhomogeneous PL broadening to the overall emission features of AIS/ZnS QDs originating from radiative transitions from a set of energy states of defects localized at different positions within the quantum dot volume, in addition to contributions from dimensional and chemical broadening. This mechanism was confirmed by numerically modelling the absorption and PL energies with a simple mass approximation for spherical QDs and a modified donor-acceptor model, thereby utilizing the advantages of previously proposed PL mechanisms of ternary QDs. These findings will pave the road to a deeper understanding of the nature of PL in quantum confined I-III-VI group semiconductor nanomaterials.

Magneto-optic Faraday effect in unaligned single-wall carbon nanotube thin films with different geometric parameters on transparent float glass substrates was experimental studied in a frequency range 0:2–0:8 THz (corresponding to a range from ~1:50mm to ~0:37mm) at a controlled room temperature of 291–293K, and a relative humidity of 40–45%. A change of 15° in an azimuth angle, and of 10° in an ellipticity angle was achieved. The results show that by using carbon nanomaterials-based structures it is possible to devise efficient tunable polarizers that can be used in the advanced areas of terahertz nanophotonics.