Microwave Receiving System Based on Cryogenic Sensors for the Optical Big Telescope Alt-Azimuth.

This article presents the results of evaluating the possibility of conducting radio astronomy studies in the windows of atmospheric transparency ~100, ~230, and ~350 GHz using the optical Big Telescope Alt-Azimuthal (BTA) of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). A list of some promising astronomical tasks is proposed. The astroclimat conditions at the BTA site and possible optical, cryogenic, and mechanical interfaces for mounting a superconducting radio receiver at the focus of the optical telescope are considered. As a receiving system, arrays of detectors cooled to ~0.3 K based on the superconductor-insulator-normal metal-insulator-superconductor (SINIS) structure are proposed. The implementation of the project will make it possible to use the BTA site of the SAO RAS not only to solve some astronomical problems (it is possible to consider the implementation of a single observatory, the VLBI (very-long-baseline interferometry) mode in the Suffa, EHT (Event Horizon Telescope), and Millimetron projects), but it will also be used to test various cryogenic detectors in a real observatory.

Post-Implantation Inflammatory Responses to Xenogeneic Tissue-Engineered Cartilage Implanted in Rabbit Trachea: The Role of Cultured Chondrocytes in the Modification of Inflammation.

Immune responses to tissue-engineered grafts made of xenogeneic materials remain poorly studied. The scope of current investigations is limited by the lack of information on orthotopically implanted grafts. A deeper understanding of these processes is of great importance since innovative surgical approaches include the implantation of xenogeneic decellularized scaffolds seeded by cells. The purpose of our work is to study the immunological features of tracheal repair during the implantation of tissue-engineered constructs based on human xenogeneic scaffolds modified via laser radiation in rabbits. The samples were stained with hematoxylin and Safranin O, and they were immunostained with antibodies against tryptase, collagen II, vimentin, and CD34. Immunological and inflammatory responses were studied by counting immune cells and evaluating blood vessels and collagen. Leukocyte-based inflammation prevailed during the implantation of decellularized unseeded scaffolds; meanwhile, plasma cells were significantly more abundant in tissue-engineered constructs. Mast cells were insignificantly more abundant in tissue-engineered construct samples. Conclusions: The seeding of decellularized xenogeneic cartilage with chondrocytes resulted in a change in immunological reactions upon implantation, and it was associated with plasma cell infiltration. Tissue-engineered grafts widely differed in design, including the type of used cells. The question of immunological response depending on the tissue-engineered graft composition requires further investigation.

Microwave Cavity Sensor for Measurements of Air Humidity under Reduced Pressure.

A high-sensitivity sensor for measuring moisture content in the air or air humidity under low pressure was designed on the basis of a half-wave coaxial microwave cavity. The method of measuring small variations in the signal phase at a cavity excitation frequency of 1.63 GHz was applied to detect low densities of water vapor. It allows the detection of variations in dielectric air permittivity in the seventh decimal place. A prototype of the sensor was tested in a vacuum chamber. It was calibrated by comparing the test results with the readings of a commercial pressure gauge and using the independent method of measuring the moisture content in rarefied air on the basis of the absorption of millimeter waves in the local line of water vapor at 183 GHz. The developed sensor can be used in laboratory experiments and full-scale geophysical research in the atmosphere onboard various aircrafts.

Millimeter-Wave Imaging System Based on Direct-Conversion Focal-Plane Array Receiver.

A new approach to millimeter-wave imaging was suggested and experimentally studied. This approach can be considered as the evolution of the well-established focal-plane array (FPA) millimeter-wave imaging. The significant difference is the use of a direct-conversion array receiver, instead of the direct-detection array receiver, along with the frequency-modulated continuous-wave (FMCW) radar technique. The sensitivity of the direct-conversion receiver is several orders higher than the sensitivity of the direct-detection one, which allows us to increase the maximum imaging range by more than one order of magnitude. The additional advantage of the direct-conversion technique is the opportunity to obtain information about the range to an object. The realization of the direct-conversion FPA imaging system was made possible due to original sensitive simple-designed receiving elements based on low-barrier Mott diodes. The suggested imaging method's main characteristics, which include the achievable angular and range resolution and the achievable maximum imaging range, were studied. A maximum range of up to 100 m was experimentally determined. A 94 GHz 8 × 8 imaging system was developed for demonstration purposes and studied in detail. The suggested technique is assumed to be useful for creating a long-range millimeter-wave camera, in particular, for robotic systems that operate in poor environmental conditions.

A method for intra-percardial PDT for malignant mesothelioma.

We describe a case of a 35-year-old patient with recurrent non-resectable pleural mesothelioma cT4N0M0 with a confirmed malignant pericardial effusion, threatening for cardiac tamponade. We performed and described our experience of intrapericardial photodynamic therapy which was well tolerated and with a good survival result. After 12 months of follow-up our patient showed no signs of pericardial effusion and in stable condition, keeping high level of quality of life. This clinical case is an example of the excellent palliative effect of photodynamic therapy together with concomitant immunotherapy.

On the possibility of photodynamic inactivation of tracheobronchial tree pathogenic microbiota using methylene blue (in vitro study).

BACKGROUND: The treatment of patients after mechanical ventilation of lungs suffering from a multi-species infection of the tracheobronchial tree can be complicated.. The situation is aggravated in patients with post-intubation tracheal stenosis, where infection plays a leading pathogenetic role in damage to the tracheal wall. As a result of such a pathological process, cicatricial stenosis of the trachea of purulent-inflammatory infectious genesis or infected tracheal stenosis (ITS) may occur. METHODS: In this work, we studied the possibility of photodynamic inactivation of pathogenic microbiota typical for patients with ITS using methylene blue (MB) as a photosensitizer. RESULTS: 13 clinical isolates of 8 species of bacteria from 9 patients were susceptible to photodynamic inactivation with MB. 30 µM of MB at a light irradiation dose of 25 J/cm2 and incubation with MB for 15 min allows to completely inactivate bacteria found in the tracheobronchial secretions of patients with ITS. CONCLUSIONS: MB retains its optico-physical properties in the range of 3-30 µM and provides effective inactivation of isolated Gram-positive and Gram-negative bacteria, including multi- and pan-resistant to antibiotics.

Engineering of Tracheal Grafts Based on Recellularization of Laser-Engraved Human Airway Cartilage Substrates.

OBJECTIVE: Implantation of tissue-engineered tracheal grafts represents a visionary strategy for the reconstruction of tracheal wall defects after resections and may develop into a last chance for a number of patients with severe cicatricial stenosis. The use of a decellularized tracheal substrate would offer an ideally stiff graft, but the matrix density would challenge efficient remodeling into a living cartilage. In this study, we hypothesized that the pores of decellularized laser-perforated tracheal cartilage (LPTC) tissues can be colonized by adult nasal chondrocytes (NCs) to produce new cartilage tissue suitable for the repair of tracheal defects. DESIGN: Human, native tracheal specimens, isolated from cadaveric donors, were exposed to decellularized and laser engraving-controlled superficial perforation (300 µm depth). Human or rabbit NCs were cultured on the LPTCs for 1 week. The resulting revitalized tissues were implanted ectopically in nude mice or orthotopically in tracheal wall defects in rabbits. Tissues were assayed histologically and by microtomography analyses before and after implantation. RESULTS: NCs were able to efficiently colonize the pores of the LPTCs. The extent of colonization (i.e., percentage of viable cells spanning >300 µm of tissue depth), cell morphology, and cartilage matrix deposition improved once the revitalized constructs were implanted ectopically in nude mice. LPTCs could be successfully grafted onto the tracheal wall of rabbits without any evidence of dislocation or tracheal stenosis, 8 weeks after implantation. Rabbit NCs, within the LPTCs, actively produced new cartilage matrix. CONCLUSION: Implantation of NC-revitalized LPTCs represents a feasible strategy for the repair of tracheal wall defects.

Biomedical Applications of Non-Small Cell Lung Cancer Spheroids.

Lung malignancies accounted for 11% of cancers worldwide in 2020 and remained the leading cause of cancer deaths. About 80% of lung cancers belong to non-small cell lung cancer (NSCLC), which is characterized by extremely high clonal and morphological heterogeneity of tumors and development of multidrug resistance. The improvement of current therapeutic strategies includes several directions. First, increasing knowledge in cancer biology results in better understanding of the mechanisms underlying malignant transformation, alterations in signal transduction, and crosstalk between cancer cells and the tumor microenvironment, including immune cells. In turn, it leads to the discovery of important molecular targets in cancer development, which might be affected pharmaceutically. The second direction focuses on the screening of novel drug candidates, synthetic or from natural sources. Finally, "personalization" of a therapeutic strategy enables maximal damage to the tumor of a patient. The personalization of treatment can be based on the drug screening performed using patient-derived tumor xenografts or in vitro patient-derived cell models. 3D multicellular cancer spheroids, generated from cancer cell lines or tumor-isolated cells, seem to be a helpful tool for the improvement of current NSCLC therapies. Spheroids are used as a tumor-mimicking in vitro model for screening of novel drugs, analysis of intercellular interactions, and oncogenic cell signaling. Moreover, several studies with tumor-derived spheroids suggest this model for the choice of "personalized" therapy. Here we aim to give an overview of the different applications of NSCLC spheroids and discuss the potential contribution of the spheroid model to the development of anticancer strategies.

Rare diseases of esophagus: Surgical treatment of cysts in adults. Case report.

INTRODUCTION AND IMPORTANCE: Esophageal cysts (EC) are congenital, extremely rare malformation. Up to 80% of EC are diagnosed in childhood, therefore, we can find only few clinical observations of EC in adults in literature. CASE PRESENTATION: During the period from October to December 2019, a successful surgical treatment of 2 patients (1 male and 1 female) with enterogenous and duplication cysts of esophagus was performed at the Clinic of Faculty Surgery at Sechenov University. In both cases thoracic tumors were incidental findings during routine health investigation. CLINICAL DISCUSSION: Clinical manifestations of ECs are caused by compression or displacement of the adjacent anatomical structures, therefore, most often patients complain of dysphagia, vomiting, pain in the chest, which may be constant or occur during an act of breathing. There are also observations of neurological symptoms due to compression of the radicular nerves The method of choice in the treatment of ECs is their surgical removal. CONCLUSION: Patients with mediastinal tumors should be treated in specialized hospitals by experienced surgeons who can cope with an unexpected intraoperative finding and carry out the appropriate surgery.

Experimental animal model for assessment of tracheal epithelium regeneration.

OBJECTIVES/HYPOTHESIS: To develop an experimental model in rabbits for assessment of tracheal epithelium regeneration through application of either natural or artificial polymer scaffolds. STUDY DESIGN: First, we identified the size of full-thickness mucosal defect, which does not allow self-healing (a "critical defect"), thus representing an adequate experimental model for regenerative therapy of tracheal epithelium damage. Then, two methods of polymer scaffold fixation at the site of the epithelium defect were compared: suturing and fixation with a stent. This was done through: 1) formation of a full-thickness anterolateral mucosal defect by tracheal mucosa excision; and 2) fixation of the scaffold at the site of the tracheal epithelium defect using sutures (through a tracheal wall "window") or a vascular stent (through a small tracheal incision). RESULTS: The dimension of a critical anterolateral mucosal defect of the trachea for rabbits was found to be 1.5 cm in length and more than 50% of the tracheal circumference. Fixation of the scaffold with a stent proved to be more efficient due to a uniform distribution of the pressure over the entire surface of the scaffold, whereas the suturing of the scaffold provided unsatisfactory results. In addition, fixation of the scaffold by suturing required formation of a large "window" in the tracheal wall. Thus, using the stent appeared to be technically less complicated and much less traumatic as compared to suturing. CONCLUSION: We present an experimental in vivo animal model of tracheal epithelium injury and recovery. It can be effectively used with certain further modifications as a basis for routine testing of bioengineered constructs. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E213-E219, 2019.

Risk of thyroid cancer after exposure to 131I in childhood.

BACKGROUND: After the Chernobyl nuclear power plant accident in April 1986, a large increase in the incidence of childhood thyroid cancer was reported in contaminated areas. Most of the radiation exposure to the thyroid was from iodine isotopes, especially 131I. We carried out a population-based case-control study of thyroid cancer in Belarus and the Russian Federation to evaluate the risk of thyroid cancer after exposure to radioactive iodine in childhood and to investigate environmental and host factors that may modify this risk. METHODS: We studied 276 case patients with thyroid cancer through 1998 and 1300 matched control subjects, all aged younger than 15 years at the time of the accident. Individual doses were estimated for each subject based on their whereabouts and dietary habits at the time of the accident and in following days, weeks, and years; their likely stable iodine status at the time of the accident was also evaluated. Data were analyzed by conditional logistic regression using several different models. All statistical tests were two-sided. RESULTS: A strong dose-response relationship was observed between radiation dose to the thyroid received in childhood and thyroid cancer risk (P<.001). For a dose of 1 Gy, the estimated odds ratio of thyroid cancer varied from 5.5 (95% confidence interval [CI] = 3.1 to 9.5) to 8.4 (95% CI = 4.1 to 17.3), depending on the risk model. A linear dose-response relationship was observed up to 1.5-2 Gy. The risk of radiation-related thyroid cancer was three times higher in iodine-deficient areas (relative risk [RR]= 3.2, 95% CI = 1.9 to 5.5) than elsewhere. Administration of potassium iodide as a dietary supplement reduced this risk of radiation-related thyroid cancer by a factor of 3 (RR = 0.34, 95% CI = 0.1 to 0.9, for consumption of potassium iodide versus no consumption). CONCLUSION: Exposure to (131)I in childhood is associated with an increased risk of thyroid cancer. Both iodine deficiency and iodine supplementation appear to modify this risk. These results have important public health implications: stable iodine supplementation in iodine-deficient populations may substantially reduce the risk of thyroid cancer related to radioactive iodines in case of exposure to radioactive iodines in childhood that may occur after radiation accidents or during medical diagnostic and therapeutic procedures.

Non-cancer thyroid diseases among children in the Kaluga and Bryansk regions of the Russian Federation exposed to radiation following the Chernobyl accident.

This paper presents results of estimated radiation risks of non-cancer thyroid diseases in the people from Kaluga and Bryansk regions of the Russian Federation exposed in their childhood to radioiodine as a result of the Chernobyl accident. This work was carried out under the Joint Medical Research Project on non-cancer thyroid diseases conducted by Sasakawa Memorial Health Foundation and the Medical Radiological Research Center of the Russian Academy of Medical Sciences. The subjects were 2,457 people who underwent health examinations from 1997 to the end of 1999 who had individual radiometric thyroid data obtained between May and June 1986 and were aged 10 y or less at the time of exposure. The thyroid absorbed doses from incorporated 131I were estimated on the basis of measurements of exposure dose rate in the vicinity of the subject's thyroid and liver. A compartment model accounting for 131I metabolism in humans and cows was used. The estimated dose varied from 0 to 6 Gy, and its distribution was approximately lognormal with a mean of 0.132 Gy and standard deviation of 0.45 Gy. The prevalence of diffuse goiter in males showed a significant dose-response (p = 0.03) with an estimated odds ratio 1.36 at 1 Gy.