Reversal of crystallization in cryoprotected samples by laser editing.

Advances in cryobiology techniques commonly target either the cooling or the warming cycle, while little thought has been given to ≪repair≫ protocols applicable during cold storage. In particular, crystallization is the dominant threat to cryopreserved samples but proceeds from small nuclei that are innocuous if further growth is forestalled. To this end, we propose a laser editing technique that locally heats individual crystals above their melting point by a focused nanosecond pulse, followed by amorphization during rapid resolidification. As a reference, we first apply the approach to ice crystals in cryoprotected solution and use Raman confocal mapping to study the deactivation of crystalline order. Then, we examine dimethyl sulfoxide trihydrate crystals that can germinate at low temperatures in maximally freeze concentrated regions, as commonly produced by equilibrium cooling protocols. We show how to uniquely identify this phase from Raman spectra and evidence retarded growth of laser-edited crystals during warming.

Free-space combiner based on holographic mirrors for head-mounted displays.

The paper presents an augmented reality display based on the free-space combiner, consisting of two holographic mirrors: flat and spherical. A feature of such a system is a high-reflection coefficient of mirrors up to 90% for one wavelength and a high transmittance to the lumen up to 67% throughout the rest of the visible spectrum, unlike similar solutions implementing principles of polarization or dichroic beam splitting. The recording scheme and calculation of a separate flat holographic mirror and spherical holographic mirror are described. The proposed augmented reality display can provide multifocality, i.e., reproduction of virtual images at several distances, which demonstrates a certain perspective of this implementation in terms of compensation for the vergence accommodation conflict.

Strategies to enhance stress tolerance in lactic acid bacteria across diverse stress conditions.

Lactic acid bacteria (LAB) hold significant importance in diverse fields, including food technology, industrial biotechnology, and medicine. As basic components of starter cultures, probiotics, immunomodulators, and live vaccines, LAB cells resist a variety of stressors, including temperature fluctuations, osmotic and pH shocks, exposure to oxidants and ultraviolet radiation, substrate deprivation, mechanical damage, and more. To stay alive in these adversities, LAB employ a wide range of stress response strategies supported by various mechanisms, for example rearrangement of metabolism, expression of specialized biomolecules (e.g., chaperones and antioxidants), exopolysaccharide synthesis, and complex repair and regulatory systems. LAB can coordinate responses to various stressors using global regulators. In this review, we summarize current knowledge about stress response strategies used by LAB and consider mechanisms of response to specific stressful factors, supported by illustrative examples. In addition, we discuss technical approaches to increase the stress resistance of LAB, including pre-adaptation, genetic modification of strains, and adjustment of cultivation conditions. A critical analysis of the recent findings in this field augments comprehension of stress tolerance mechanisms in LAB, paving the way for prospective research directions with implications in fundamental and practical areas.

[Genetic factors in degenerative disc disease]. / Rol' geneticheskikh faktorov v razvitii degenerativno-distroficheskogo porazheniya mezhpozvonkovykh diskov.

OBJECTIVE: To analyze available literature data on the role of genetic factors in degenerative disc disease. METHODOLOGY: We reviewed the PubMed, MEDLINE, Cohrane Library, e-Library databases using the following keywords: degenerative spine lesions, intervertebral disc herniation, pathogenesis, genetic regulation. RESULTS: Searching depth was 2002-2022. We reviewed 84 references. Exclusion criteria: duplicate publications, reviews without detailed description of results, opinions. Finally, we included 43 the most significant studies. CONCLUSION: There are literature data on proinflammatory cytokines, growth factors and osteodestructive processes in pathogenesis of degenerative disc disease. However, there is only fragmentary information about the role of genetic regulation of these processes. Some factors, such as microRNA, TGF-b, VEGF, MMP are still poorly understood.

[Spatial Reconstruction of TRPC Mechanoreceptors of the Ctenophore Mnemiopsis leidyi A. Agassiz, 1865].

The ctenophore Mnemiopsis leidyi A. Agassiz, 1865 responds to gentle mechanical stimulus with intense luminescence; however, the mechanism of this phenomenon is unknown. We searched for possible mechanosensitive receptors that initiate signal transduction resulting in photoprotein luminescence. The three orthologous genes of mouse (5z96) and drosophila (5vkq) TRPC-proteins, such as ML234550a-PA (860 a.a.), ML03701a-PA (828 a.a.), and ML038011a-PA (1395 a.a.), were found in the M. leidyi genome. The latter protein contains a long ankyrin helix consisting of 16 ANK domains. Study of the annotated domains and the network of interactions between the interactome proteins suggests that the ML234550a-PA and ML03701a-PA proteins carry out cytoplasmic transduction, but ML038011a-PA provides intranuclear transduction of mechanical signals. Spatial reconstruction of the studied proteins revealed differences in their structure, which may be related to various functions of these proteins in the cell. The question of which of these proteins is involved in the initiation of luminescence after mechanical stimulation is discussed.

[Spatial Models of Piezo Proteins and Protein-Protein Interaction Networks in Trichoplax Animals (Placozoa)].

The marine free-living organism Trichoplax (phylum Placozoa) resembles a unicellular amoeba in shape and type of movement. Trichoplax diverged from the main evolutionary tree in the Neoproterozoic Era. Trichoplax provides one of the simplest models of multicellular animals and a strong example of how cells of an organism interact to form an ensemble during its development and movement. Two orthologs of the mouse Piezo1 protein (6B3R) were found in two Trichoplax haplotypes, H1 and H2, as a result of a search for similar sequences in the NCBI databases. Spatial models of the respective proteins XP_002112008.1 and RDD46920.1 were created via a structural alignment with 6KG7 (mouse Piezo2) template. Their domain structures were analyzed, and a limited graph of protein-protein interactions was constructed for the hypothetical mechanosensor XP_002112008.1. The possibility of signal transduction from the mechanoreceptor to membrane complexes, the cytoplasm, and the cell nucleus was shown. Trichoplax mechanoreceptors were assumed to play a role in perception of force stimuli from neighbor cells and the environment. Based on the results, the primitive Trichoplax organism was proposed as the simplest multicellular model of mechanical and morphogenetic movements.

[In-hospital mortality in acute abdominal diseases in the Central Federal District of Russia depending on availability of laparoscopic procedures]. / Dinamika gospital'noi letal'nosti pri ostrykh abdominal'nykh zabolevaniyakh v Tsentral'nom federal'nom okruge Rossii v zavisimosti ot chastoty primeneniya laparoskopicheskikh operatsii.

OBJECTIVE: To study in-hospital mortality in acute abdominal diseases in the Central Federal District and compared effectiveness of laparoscopic and open surgeries. MATERIAL AND METHODS: The study was based on the previous data for 2017-2021. The odds ratio (OR) was used to assess significance of between-group differences. RESULTS: The absolute number of deceased patients with acute abdominal diseases increased significantly and exceeded 23 thousand in the Central Federal District between 2019 and 2021. This value approached 4% for the first time over the last 10 years. In-hospital mortality from acute abdominal diseases in the Central Federal District increased for 5 years and reached maximum value in 2021. The greatest changes occurred in perforated ulcers (mortality increased from 8.69% in 2017 to 14.01% in 2021), acute intestinal obstruction (from 4.7% to 9.0%) and ulcerative gastroduodenal bleeding (from 4.5% to 5.5%). In other diseases, in-hospital mortality is lower, but trends are similar. Laparoscopic surgeries are common in acute cholecystitis (71-81%). At the same time, in-hospital mortality is significantly lower in regions with more active use of laparoscopy (0.64% and 1.25% in 2020; 0.52% and 1.16% in 2021). Laparoscopic surgeries are significantly less actively used for other acute abdominal diseases. We analyzed availability of laparoscopic surgeries using the «Hype Cycle¼. Percentage range of introduction reached conditional «productivity plateau¼ only in acute cholecystitis. CONCLUSION: Most regions are stagnating in laparoscopic technologies for acute appendicitis and perforated ulcers. Laparoscopic operations are actively used for acute cholecystitis in most regions of the Central Federal District. Annual increase in the number of laparoscopic operations and their technical improvement are promising in reducing in-hospital mortality associated with acute appendicitis, perforated ulcers and acute cholecystitis.

[Etiopathogenetic substantiation of surgical treatment of neurogenic pain syndromes]. / Etiopatogeneticheskoe obosnovanie khirurgicheskogo lecheniya neirogennykh bolevykh sindromov.

The purpose of the study was to improve classification of neurogenic (neuropathic) pain syndromes. This will make it possible to define the indications for appropriate analgesic surgery for each type of drug-resistant neurogenic pain syndrome. Incorrect management of neurogenic pain syndromes is usually associated with underestimation of pathogenetic prerequisites for its occurrence. Differentiation of compression, deafferentation and mixed neurogenic pain syndromes makes it possible to determine appropriate surgery and avoid tactical errors. Moreover, this approach allows you to save patients from unreasonable long-standing suffering. Patients with chronic pain syndromes often become disabled, sometimes in the prime of life, and isolated from society and family. Therefore, treatment of chronic pain is currently an urgent problem.

Broad temperature range ferrielectric liquid crystal as a highly sensitive quadratic electro-optical material.

A chiral smectic liquid crystal in which a ferrielectric phase with a helix pitch p0 less than 125 nm exists over a temperature range of at least from -3°C to +36°C has been developed. Such a wide temperature range (including room temperatures) of the ferrielectric phase with a subwavelength helix pitch has been achieved for the first time, to the best of our knowledge, which creates opportunities for the practical use of ferrielectric liquid crystals. A quadratic electro-optical effect caused by deformations of the helix in an electric field is observed in the ferrielectric phase, and the Kerr coefficient, which reaches almost 200 nm/V2, is significantly higher than the same coefficient for the blue phase and for the smectic C* phase, which means a higher sensitivity of the developed ferrielectric liquid crystal to the electric field. The electro-optical response time does not exceed 300 µs at room temperatures for this ferrielectric liquid crystal.

Postpartum Involution of Mouse Myometrium in Acute CCl4-Induced Hepatosis and Its Correction with Immobilized Hyaluronidase.

We studied structural rearrangement of the myometrium of C57BL/6 mice during the postpartum period under conditions of acute toxic hepatosis induced by CCl4 injection and its correction with immobilized hyaluronidase. In contrast to physiological pregnancy, involution of the myometrium in mice under conditions of acute toxic hepatosis were not completed by the 10th day of the postpartum period. When toxic hepatosis was corrected with immobilized hyaluronidase, the main mechanism of postpartum involution of the mouse myometrium was clasmacytosis, the process of postpartum involution was significantly accelerated, but not completed by the 10th day, probably due to reduced vascularization of the myometrium.

[Mortality in acute appendicitis in Russia]. / Letal'nost' pri ostrom appenditsite v Rossii.

OBJECTIVE: To analyze the causes of mortality in patients with acute appendicitis in Russia. MATERIAL AND METHODS: We retrospectively studied mortality in patients with acute appendicitis in the Russian Federation in 2020. We surveyed the hospitals with mortality reported in the electronic database of annual reports to the chief surgeon of the Ministry of Health of the Russian Federation. RESULTS: There were 259 deaths among 150.393 patients with acute appendicitis aged ≥18 years (in-hospital mortality 0.17%). We obtained data about 95.8% (n=248) of lethal cases including 86.3% (n=214) complicated and 13.7% (n=34) uncomplicated forms of disease. Two patients died without surgery (0.8%). Among the deceased, 58.2% (n=145) were men and 41.8% (n=103) were women. Mean patient age was 66.2 years [0.95% CI 64.2-68.1]. The main cause of death in complicated appendicitis was late presentation (after 4.9 days [0.95% CI 4.3-5.4]) that resulted peritonitis and sepsis in 71.5% (n=153) of patients. Cardiovascular diseases were noted in 23.4% (n=50) of cases. A new coronavirus infection was detected in 7.0% (n=15) of patients. However, COVID-19 as a direct cause of death was recognized in 2.8% (n=6) of cases. Other reasons accounted for 2.3% (n=5). In uncomplicated appendicitis, cardiovascular diseases were the main cause of mortality (73.5%, n=25). Peritonitis and sepsis were found in 11.8% (n=4) of cases, COVID-19 - in 5.9% (n=2). Other causes accounted for 8.8% (n=3). Diagnostic, tactical, technical problems and their combination were revealed in 54.4% of lethal outcomes. CONCLUSION: Mortality from acute appendicitis in the Russian Federation is low, comparable with international data, and mainly associated with delayed treatment and complicated course of disease. However, the impact of diagnostic, tactical and technical errors on the outcome of acute appendicitis is significant.

[Surgical treatment of thoracic spine fracture in a patient with ankylosing spondylitis: case report and literature review]. / Khirurgicheskoe lechenie pereloma grudnogo otdela pozvonochnika na fone ankiloziruyushchego spondilita: klinicheskii sluchai i obzor literatury.

OBJECTIVE: To describe the features of diagnosis and surgical treatment of thoracic spine fracture in a patient with ankylosing spondylitis. MATERIAL AND METHODS: We present a patient with ankylosing spondylitis, blunt thoracic spine trauma and Th10-Th11 fracture, spinal cord compression and contusion and moderate lower extremity paresis. Preoperative and postoperative CT and MRI (after 8 months) were performed for control of decompression. RESULTS: The authors identified the main factors affecting the quality of life of patients with spine fractures following ankylosing spondylitis and formulated treatment algorithm. CONCLUSION: Active strategy is advisable for spine fractures following ankylosing spondylitis: spinal cord decompression, creation of anatomical compliance in the damaged vertebral segment and its fixation by transpedicular system. A similar surgical treatment of spine fractures following ankylosing spondylitis makes it possible to achieve early activation of patients and reduce rehabilitation period.

[Impact of staffing on the results of treatment among surgical patients. Statistical study]. / Vliyanie kadrovoi ukomplektovannosti na rezul'taty lecheniya khirurgicheskikh bol'nykh. Statisticheskoe issledovanie.

OBJECTIVE: To study the influence of staffing index on the results of surgical treatment. MATERIAL AND METHODS: The study was based on the data of surgical service in the Russian Federation upon 2018 (A.Sh. Revishvili et al., 2019). Correlation and regression analysis was carried out using the Microsoft Excel 2019 software. To assess between-group differences, we analyzed odds ratio (OR) and contingency table using χ2 test. RESULTS: Correlation and regression analysis revealed strong direct functional relationships (r=0.889) between the staffing of surgical service and in-hospital mortality rates. We distinguished 3 formalized levels of surgical staffing (high, medium and low). Gradation of these categories depends on the annual average reference indicator of staffing (88.4% in 2018). In high level of surgical staffing (≥88.4%), in-hospital mortality was 2.19%. Low level of surgical staffing (<88.4%) is accompanied by in-hospital mortality of 2.65% (OR 0.83; 95% CI 0.81-0.84; p<0.05). CONCLUSION: We confirmed the hypothesis about correlation of in-hospital mortality and staffing of surgical personnel. Validation of scientific data requires further studies with multivariate analysis of various covariates. Long-term prospects of surgical personnel policy in Russia are associated with formulation of specific tasks for surgical services at each level of surgical care.

[Comparison of robot-assisted and conventional endoscopic surgeries in the Russian Federation. (A systematic review and meta-analysis)]. / Sravnenie robot-assistirovannykh i traditsionnykh videoendoskopicheskikh operatsii v RF. (Rezul'taty sistematicheskogo obzora i metaanaliza).

OBJECTIVE: Comparative assessment of immediate and long-term results of robot-assisted and conventional endoscopic technologies in the Russian Federation. MATERIAL AND METHODS: Searching for primary trials devoted to robot-assisted (RAE) and traditional video endoscopic (TVE) surgeries in the Russian Federation was carried out in the e-library and CENTRAL Cochrane databases. We used the recommendations of the Center for Expertise and Quality Control of Medical Care (2017, 2019) and the current version of the Cochrane Community Guidelines (2021). These guidelines define the features of meta-analysis of non-randomized comparative studies. Review Manager 5.4 software was used for statistical analysis. RESULTS: We enrolled 26 Russian-language primary sources (3111 patients) including 1174 (38%) ones in the RAE group and 1937 (62%) patients in the TVE group. There were no randomized controlled trials in the Russian Federation, and all primary studies were non-randomized. We found no significant between-group differences in surgery time, incidence of intraoperative complications, intraoperative blood loss in thoracic surgery, urology and gynecology, conversion rate, postoperative hospital-stay, postoperative morbidity (in abdominal surgery, urology and gynecology), postoperative mortality. We observed slightly lower intraoperative blood loss for RAE in abdominal surgery and lower incidence of postoperative complications in robot-assisted thoracic surgery. These results can be compromised by methodological quality of comparative studies, significant heterogeneity and systematic errors. CONCLUSION: Currently, we cannot confirm the benefits of robot-assisted technologies, since this approach does not worsen or improve treatment outcomes. Further high-quality studies are needed.

[Kinesiophobia in patients requiring hip and knee endoprosthetics: severity and provoking factors]. / Kineziofobiya u patsientov, nuzhdayushchikhsya v endoprotezirovanii tazobedrennogo i kolennogo sustavov: vyrazhennost' i provotsiruyushchie faktory.

Kinesiophobia (KP), or an irrational fear of physical activity, significantly hinders the active rehabilitation of patients with joint pathology. PURPOSE OF THE STUDY: To study the severity and risk factors of KP in patients requiring total hip and knee endoprosthetics (EP). MATERIAL AND METHODS: We examined 50 patients requiring total EP of the hip and knee joints. Pain syndrome was assessed in the preoperative and early postoperative periods in all patients using a visual analog scale, as well as the levels of kinesiophobia, anxiety, and depression using the Hospital Anxiety and Depression Scale and the Tampa Scale for Kinesiophobia (TSK). Quality of patients life was studied in the preoperative period (RAND SF36 questionnaire). RESULTS: In the majority of cases, both before and after EP, the level of KP corresponded to an average degree of severity. Both in the preoperative and in the early postoperative periods, not a single case of the absence of KP was detected (≤17 points according to the TSK); at the same time, a very high level of KP (≥55 points according to TSK) was also rarely recorded - in 3 patients in the postoperative period after EP of the hip joint. KP level significantly correlated with the duration of the pain syndrome, while the mental component of the KP, in addition to the duration of the pain syndrome, was influenced by the social status: in patients who had a steady job, the psychological component of the KP was expressed in a less degree. KP level was negatively correlated with such indicators of quality of life as vitality and physical functioning. In addition, the physical component of the KP significantly correlated with the pain intensity, the mental component - with role-playing behavior. CONCLUSION: Early detection of KP and timely correction of distorted ideas about physical activity are necessary for successful rehabilitation of patients requiring total joint endoprosthetics of the lower limb.

Multimode LD-pumped all-fiber Raman laser with excellent quality of 2nd-order Stokes output beam at 1019†nm.

A multimode all-fiber Raman laser enabling cascaded generation of high-quality 1019-nm output beam at direct pumping by highly-multimode (M2>30) 940-nm laser diodes has been demonstrated. The laser is made of a 100/140 graded-index fiber with special in-fiber Bragg gratings which secure sequential generation of the 1st (976 nm) and 2nd (1019 nm) Stokes orders. Comparing different 1019-nm cavity structures shows that the half-open cavity with one FBG and distributed feedback via random Rayleigh backscattering provides excellent quality (M2∼1.3) with higher slope efficiency of pump-to-2nd Stokes conversion than in the conventional 2-FBG cavity. The maximum achieved slope efficiency amounts to about 40% at output powers of up to 12 W limited by the 3rd Stokes generation.

Broad Diversity of Near-Infrared Single-Photon Emitters in Silicon.

We report the detection of individual emitters in silicon belonging to seven different families of optically active point defects. These fluorescent centers are created by carbon implantation of a commercial silicon-on-insulator wafer usually employed for integrated photonics. Single photon emission is demonstrated over the 1.1-1.55 µm range, spanning the O and C telecom bands. We analyze their photoluminescence spectra, dipolar emissions, and optical relaxation dynamics at 10 K. For a specific family, we show a constant emission intensity at saturation from 10 K to temperatures well above the 77 K liquid nitrogen temperature. Given the advanced control over nanofabrication and integration in silicon, these individual artificial atoms are promising systems to investigate for Si-based quantum technologies.

Magnetospherically driven optical and radio aurorae at the end of the stellar main sequence.

Aurorae are detected from all the magnetized planets in our Solar System, including Earth. They are powered by magnetospheric current systems that lead to the precipitation of energetic electrons into the high-latitude regions of the upper atmosphere. In the case of the gas-giant planets, these aurorae include highly polarized radio emission at kilohertz and megahertz frequencies produced by the precipitating electrons, as well as continuum and line emission in the infrared, optical, ultraviolet and X-ray parts of the spectrum, associated with the collisional excitation and heating of the hydrogen-dominated atmosphere. Here we report simultaneous radio and optical spectroscopic observations of an object at the end of the stellar main sequence, located right at the boundary between stars and brown dwarfs, from which we have detected radio and optical auroral emissions both powered by magnetospheric currents. Whereas the magnetic activity of stars like our Sun is powered by processes that occur in their lower atmospheres, these aurorae are powered by processes originating much further out in the magnetosphere of the dwarf star that couple energy into the lower atmosphere. The dissipated power is at least four orders of magnitude larger than what is produced in the Jovian magnetosphere, revealing aurorae to be a potentially ubiquitous signature of large-scale magnetospheres that can scale to luminosities far greater than those observed in our Solar System. These magnetospheric current systems may also play a part in powering some of the weather phenomena reported on brown dwarfs.

Strain Modulation of Si Vacancy Emission from SiC Micro- and Nanoparticles.

Single-photon emitting point defects in semiconductors have emerged as strong candidates for future quantum technology devices. In the present work, we exploit crystalline particles to investigate relevant defect localizations, emission shifting, and waveguiding. Specifically, emission from 6H-SiC micro- and nanoparticles ranging from 100 nm to 5 µm in size is collected using cathodoluminescence (CL), and we monitor signals attributed to the Si vacancy (VSi) as a function of its location. Clear shifts in the emission wavelength are found for emitters localized in the particle center and at the edges. By comparing spatial CL maps with strain analysis carried out in transmission electron microscopy, we attribute the emission shifts to compressive strain of 2-3% along the particle a-direction. Thus, embedding VSi qubit defects within SiC nanoparticles offers an interesting and versatile opportunity to tune single-photon emission energies while simultaneously ensuring ease of addressability via a self-assembled SiC nanoparticle matrix.

[Simultaneous surgery for papillary thyroid cancer with lymph node metastases combined with common carotid artery stenosis]. / Simul'tannoe khirurgicheskoe vmeshatel'stvo pri sochetanii papillyarnogo raka shchitovidnoi zhelezy s metastazami v limfaticheskie uzly shei i ateroskleroticheskogo stenoza bifurkatsii levoi obshchei sonnoi arterii.

The authors report simultaneous surgical treatment of papillary cancer of the left thyroid lobe with lymph nodes metastases and left common carotid artery stenosis over 70%. Carotid endarterectomy at the first stage made it possible to reduce the risk of perioperative stroke, restore adequate blood flow through the carotid arteries and simultaneously perform total resection for thyroid carcinoma.