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In this paper analytic and invariant solution of the electron motion in crossed electric and magnetic fields where H < E is examined. It is shown that the invariant solution of the proposed problem is formally similar to that of quantum harmonic oscillator. Examining the polarity operator in external field, it is deduced that there is an expression consisting of spin components which remains constant throughout the motion and therefore is integral of motion. Eigenvalues and eigenfunctions corresponding to spin integral of motion are found and analyzed. [ABSTRACT FROM AUTHOR]

The daily activities of two isolated populations of endangered species of rock lizards Darevkia rostombekowi were studied. The main aim of our study was the show the competition among syntopic species of rock lizards. Our results have shown the similarity of patterns of daily activities for lizards belonging to different species and sharing the same territories and differences in peak of their activities, which allow them to avoid the competition. [ABSTRACT FROM AUTHOR]

The article discusses the use of Digital twins technology (digital twin) in the operation of construction projects. Its application contributes to the most efficient operation of buildings and structures. The "digital twin" is constantly updated with up-to-date information: maintenance companies are engaged in updating the needs of residents, conducts diagnostics of the condition of the building as a whole. This technology helps to determine the exact timing of equipment replacement. The operated building and its systems are under constant supervision and control of management organizations. The cost of operating the building is reduced, as the building is under constant monitoring and diagnostics.

The article considers the calculation of the ultimate rupture load of multilayer floor slabs supported on three sides (two short and one long). The calculation is carried out taking into account three fracture schemes: the first scheme consists of three main destructive cracks that converge at one point, forming an "envelope"; the second scheme consists of two main inclined cracks passing from the corners towards the non-supported side and not converging on the plate field; the third scheme consists of a horizontal crack forming trapezoid in combination with angular cracks, which is the case when testing prototypes. The reduction of a three-layer section to a single-layer section is carried out according to the elasticity modules of the concretes that make up the section. The value of the rupture load is determined from the condition of equilibrium of external and internal forces. The results of the VAT analysis of multilayer reinforced concrete structures according to the proposed schemes were carried out by the authors on the basis of static tests of prototypes of flat reinforced concrete three-layer slabs. The obtained research results allow us to determine rational parameters for the design of multilayer slab structures with reinforced concrete layers of various strength.

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The choice of the optimal option for the production of in the construction of buildings and structures is based on a preliminary generalization and analysis of the most promising options for the implementation of construction and installation from which the most rational optimal in the is selected conditions under consideration. The purpose of the study is to determine the optimal option for production of at the convex cost function. We used the method of the determination of costs on the duration of works, represented by a convex function showing the shorter the duration of the project the more costs are required when it is reduced by the same amount. The key parameters affecting the final result of construction are the duration cost and quality of performed. Consequently, one of the main tasks is to draw up a works schedule with close coordination of the resources necessary for their implementation. To do this we have to solve problems associated with the distribution of limited resources. In this case, the technological interdependence between the works performed, which may be of a different nature, should be taken into account. As the results, new approaches were founded to developing a strategy for the selection of options for construction and installation works in order to ensure contractual deadlines for their implementation and minimize the funds spent on their implementation taking into account the nature of the dependencies between the works performed is an urgent and important problem.

The purpose of this article is the development of management process of redevelopment of industrial real estate, based on the criteria-based approach for accepting the form of development. Developing the proposed approach was feasible due to the study of the efforts of foreign experts and experience of the redevelopment projects in Russia. In addition, the article presents the classification of redevelopment of non-residential property, based on three main criteria’s. The proposed algorithm extends the core taking into account the specifics of the three forms of development of objects of real estate (reconstruction, modernization and redevelopment) and is focused on the development of the industrial estate.

The purpose of the study is to develop theoretical provisions and practical tools for attracting investment resources for the renewal of the fixed assets of the housing and communal services enterprises (hereinafter Housing and Communal Services). In the article the condition and reveals, the trends in the development of the housing and communal services have been analyzed, the forms and methods of the attracting investment resources have been explored, a model for identifying the most priority projects for the reconstruction and renovation of the communal infrastructure have been formed, a mechanism for searching for and attracting extra-budgetary sources of the investment has been developed, and an algorithm for monitoring the effectiveness of the using extra-budgetary sources of the investment has been formed. The research was carried out using a system approach, economic and mathematical modeling, general scientific methods, methods and statistical analysis. The processing of the information obtained through analysis and modeling was carried out using modern methods that support collection procedures.

Background: Data to guide dialysis decision-making for transplant-ineligible patients with cirrhosis are lacking., Aims: We aimed to describe the processes, predictors, and outcomes of renal replacement therapy (RRT) initiation for transplant-ineligible patients with cirrhosis at a single liver transplantation center., Methods: We conducted a mixed-methods study of a retrospective cohort of 372 transplant-ineligible inpatients with cirrhosis with acute kidney injury (AKI) due to hepatorenal syndrome (HRS-AKI) or acute tubular necrosis (ATN) between 2008 and 2015. We performed survival analyses to evaluate 6-month survival and renal recovery and examined end-of-life care outcomes. We used a consensus-driven medical record review to characterize processes leading to RRT initiation., Results: We identified 266 (71.5%) patients who received RRT and 106 (28.5%) who did not receive RRT (non-RRT). Median survival was 12.5 days (RRT) vs. 2.0 days (non-RRT) (HR 0.36, 95%CI 0.28-0.46); 6-month survival was 15% (RRT) vs. 0% (non-RRT). RRT patients were more likely to die in the intensive care unit (88% vs. 32%, p < 0.001). HRS-AKI patients were more likely to be RRT dependent at 6 months than ATN patients (86% vs. 27%, p = 0.007). The most common reasons for RRT initiation were unclear etiology of AKI on presentation (32%) and belief of likely reversibility of ATN (82%)., Conclusion: Most transplant-ineligible patients who were initiated on RRT experienced very short-term mortality and received intensive end-of-life care. However, approximately 1 in 6 were alive at 6 months. Our findings underscore the critical need for structured clinical processes to support high-quality serious illness communication and RRT decision-making for this population., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Cerebrovascular accident (CVA) is a major global contributor to death and disability. As part of its medical management, researchers have recognized the importance of promising neuroprotective strategies, where stem cell transplantation (SCT) is thought to confer advantages via trophic and neuroprotective effects., Aim: To evaluate the current state of research on SCT in patients with CVA, assess key trends and highlight literature gaps., Methods: PubMed was screened for SCT in CVA-related articles in October 2023, for each country during the period between 2000 and 2023. Using the World Bank data, total population and gross domestic product were collected for comparison. VOSviewer&#95;1.6.19 was used to create the VOS figure using the results of the same query. Graphs and tables were obtained using Microsoft Office Excel., Results: A total of 6923 studies were identified on SCT in CVA, making 0.03% of all published studies worldwide. Approximately, 68% were conducted in high-income countries, with a significant focus on mesenchymal stem cells. The journal " Stroke " featured the largest share of these articles, with mesenchymal SCT having the highest rate of inclusion, followed by hematopoietic SCT. Over time, there has been a noticeable shift from in vitro studies, which assess stem cell proliferation and neurogenesis, to in vivo studies aimed at evaluating efficacy and safety. Additionally, the number of reviews increased along this approach., Conclusion: This bibliometric analysis provides a comprehensive guide for physicians and researchers in the field through an objective overview of research activity, and highlights both current trends and gaps. Having a potential therapeutic role in CVA, more research is needed in the future to focus on different aspects of SCT, aiming to reach a better treatment strategy and improve life quality in patients., Competing Interests: Conflict-of-interest statement: The authors have no conflicts of interest to declare., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Among vertebrates, obligate parthenogenesis occurs exclusively in squamate reptiles. Premeiotic endoreplication in a small subset of developing oocytes has been documented as the mechanism of production of unreduced eggs in minutely explored obligate parthenogenetic lineages, namely in teiids and geckos. The situation in the lacertid genus Darevskia has been discussed for decades. Certain observations suggested that the ploidy level is restored during egg formation through a fusion of egg and polar body nuclei in Darevskia unisexualis and D. armeniaca . In this study, we re-evaluated the fusion hypothesis by studying diplotene chromosomes in adult females of sexual species D. raddei nairensis and obligate parthenogens D. armeniaca, D. dahli and D. unisexualis . We revealed 19 bivalents in the sexual species and 38 bivalents in the diploid obligate parthenogens, which uncovers premeiotic endoreplication as the mechanism of the production of non-reduced eggs in parthenogenetic females. The earlier contradicting reports can likely be attributed to the difficulty in identifying mispairing of chromosomes in pachytene, and the fact that in parthenogenetic reptiles relying on premeiotic endoreplication only a small subset of developing oocytes undergo genome doubling and overcome the pachytene checkpoint. This study highlights co-option of premeiotic endoreplication for escape from sexual reproduction in all independent hybrid origins of obligate parthenogenesis in vertebrates studied to date.

Background: Patients with cirrhosis and acute kidney injury (AKI) are critically ill and have high health care resource utilization (HCRU). The impact and timing of goals of care discussions on HCRU are not well described., Methods: 221 patients enrolled in a prospective cohort study of patients admitted with AKI and cirrhosis were reviewed. Documentation and timing of a goals of care discussions were analyzed as predictors of HCRU, defined as a composite outcome of intubation, initiation of renal replacement therapy, and/or admission to the intensive care unit., Results: Median MELD score was 26 [IQR 19, 33]. 29% patients were listed for liver transplant. 90-day mortality was 61%. 51% patients had at least one HCRU episode. Code status changed from admission to discharge from 91%/7%/0% to 68%/14%18% (full code/do not resuscitate/comfort measures, p < 0.001). 28% patients underwent goals of care discussions, with change in code status at a median of 16 [9, 22] days into admission. Only 18% of discussions were within 7 days of admission and all were after an HCRU event. Being listed for liver transplant was not associated with whether goals of care discussions occurred (23% listed vs. 31% non-listed, p = 0.24) but was associated with higher HCRU (69% vs. 43%; p < 0.001)., Conclusion: Goals of care discussions occurred late into the hospital course, after episodes of HCRU. Efforts should be made to engage in these discussions earlier in the hospital stay, which may decrease HCRU rates in this critically ill population and align with patients' goals of care., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Internal medicine (IM) residency is a notoriously challenging time generally characterized by long work hours and adjustment to new roles and responsibilities. The COVID-19 pandemic has led to multiple emergent adjustments in training schedules to accommodate increasing needs in patient care. The physician training period, in itself, has been consistently shown to be associated with vulnerability with respect to mental well-being. The impact of the COVID-19 pandemic on the experience of IM trainees is not well established., Objective: Characterize the impact of the COVID-19 pandemic on trainee clinical education, finances, and well-being., Methods: We developed a survey composed of 25 multiple choice questions, 6 of which had an optional short-answer component. The survey was distributed by the American College of Physicians (ACP) to 23,289 IM residents and subspecialty fellows. We received 1,128 complete surveys and an additional 269 partially completed surveys., Results: The majority of respondents reported a disruption in their clinical schedule (76%) and a decrease in both didactic conferences (71%) and protected time for education (56%). A majority of respondents (81%) reported an impact on their well-being with an increase in their level of burnout and 41% of respondents reported a decrease in level of direct supervision. Despite these changes, the majority of trainee respondents (78%) felt well prepared for clinical practice after graduation., Conclusions: These results outline the vulnerable position of internal medicine physicians in training. Preserving educational experiences, adequate supervision, and humane work hours are essential in protecting trainees from mental illness and burnout during global emergencies., (© 2023. The Author(s).)

Prion diseases are fatal neurodegenerative diseases caused by pathogenic misfolding of the prion protein, PrP. They are transmissible between hosts, and sometimes between different species, as with transmission of bovine spongiform encephalopathy to humans. Although PrP is found in a wide range of vertebrates, prion diseases are seen only in certain mammals, suggesting that infectious misfolding was a recent evolutionary development. To explore when PrP acquired the ability to misfold infectiously, we reconstructed the sequences of ancestral versions of PrP from the last common primate, primate-rodent, artiodactyl, placental, bird, and amniote. Recombinant ancestral PrPs were then tested for their ability to form β-sheet aggregates, either spontaneously or when seeded with infectious prion strains from human, cervid, or rodent species. The ability to aggregate developed after the oldest ancestor (last common amniote), and aggregation capabilities diverged along evolutionary pathways consistent with modern-day susceptibilities. Ancestral bird PrP could not be seeded with modern-day prions, just as modern-day birds are resistant to prion disease. Computational modeling of structures suggested that differences in helix 2 could account for the resistance of ancestral bird PrP to seeding. Interestingly, ancestral primate PrP could be converted by all prion seeds, including both human and cervid prions, raising the possibility that species descended from an ancestral primate have retained the susceptibility to conversion by cervid prions. More generally, the results suggest that susceptibility to prion disease emerged prior to ~100 million years ago, with placental mammals possibly being generally susceptible to disease., (© 2022 The Protein Society.)

The trematode Dicrocoelium lanceatum known as lancet fluke, is a causative agent of dicrocoeliosis, a widespread parasitic disease of the grazing ruminants. The investigation of the major neurotransmitters and their functions are an important step in the development of a new pharmacological strategy of the struggle against the dicrocoeliosis affecting the neuronal signal substances and the functions of its nervous system. The aim of this work was to study the presence and localization of the neurotransmitter serotonin (5-HT, 5-Hydroxytryptamine) in the nervous system of D. lanceatum using immunocytochemical technique and confocal laser scanning microscopy. For the first time the data on the presence and distribution of serotonin-immunopositive components in the central and peripheral compartments of the nervous system of D. lanceatum has been obtained. Serotonin-immunopositive neurons and neurites were identified in paired brain ganglia, in the brain commissure, longitudinal nerve cords and connective nerve commissures. The innervation of the oral and ventral suckers by serotonergic nerve structures was revealed. The distal part of the reproductive system and the region of the reproductive pore were intensively innervated by serotonergic neurites. Serotonin-immunopositive neurons and neurites were also revealed in the proximal region of the reproductive system. The data obtained suggest that the serotonergic nervous system is involved in the regulation of the attachment organs and the reproductive system functions in D. lanceatum. The new results on the morphological and functional organization of the D. lanceatum nervous system increase our knowledge of the structure and function of nervous system of trematodes of various taxonomic groups and support the possibility of the exploitation of the serotonergic system of the parasite as a target for anthelmintic drugs., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The use of force probes to induce unfolding and refolding of single molecules through the application of mechanical tension, known as single-molecule force spectroscopy (SMFS), has proven to be a powerful tool for studying the dynamics of protein folding. Here we provide an overview of what has been learned about protein folding using SMFS, from small, single-domain proteins to large, multi-domain proteins. We highlight the ability of SMFS to measure the energy landscapes underlying folding, to map complex pathways for native and non-native folding, to probe the mechanisms of chaperones that assist with native folding, to elucidate the effects of the ribosome on co-translational folding, and to monitor the folding of membrane proteins., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Prion and prion-like diseases involve the propagation of misfolded protein conformers. Small-molecule pharmacological chaperones can inhibit propagated misfolding, but how they interact with disease-related proteins to prevent misfolding is often unclear. We investigated how pentosan polysulfate (PPS), a polyanion with antiprion activity in vitro and in vivo, interacts with mammalian prion protein (PrP) to alter its folding. Calorimetry showed that PPS binds two sites on natively folded PrP, but one PPS molecule can bind multiple PrP molecules. Force spectroscopy measurements of single PrP molecules showed PPS stabilizes not only the native fold of PrP but also many different partially folded intermediates that are not observed in the absence of PPS. PPS also bound tightly to unfolded segments of PrP, delaying refolding. These observations imply that PPS can act through multiple possible modes, inhibiting misfolding not only by stabilizing the native fold or sequestering natively folded PrP into aggregates, as proposed previously, but also by binding to partially or fully unfolded states that play key roles in mediating misfolding. These results underline the likely importance of unfolded states as critical intermediates on the prion conversion pathway., Competing Interests: The authors declare no competing interest.

Background: It has been reported that transjugular intrahepatic portosystemic shunting (TIPS) might be utilized as a salvage option for hepatorenal syndrome (HRS), while randomized controlled trials are pending and real-world contemporary data on inpatient mortality is lacking., Methods: We conducted an observational retrospective cohort study from the National Inpatient Sample from 2005 to 2014. We included all adult patients admitted with HRS and cirrhosis, using ICD 9-CM codes. We excluded cases with variceal bleeding, Budd-Chiari, end-stage renal disease, liver transplant and transfers to acute-care facilities. TIPS' association with inpatient mortality was assessed using multivariable mixed-effects logistic regression, as well as exact-matching, thus mitigating for TIPS selection bias. The exact-matched analysis was repeated among TIPS-only versus dialysis-only patients., Results: A total of 79,354 patients were included. Nine hundred eighteen (1.2%) underwent TIPS. Between TIPS and non-TIPS groups, mean age (58 years) and gender (65% males) were similar. Overall mortality was 18% in TIPS and 48% in dialysis-only cases (n = 10,379; 13.1%). Ninety six (10.5%) TIPS patients underwent dialysis. In-hospital mortality in TIPS patients was twice less likely than in non-TIPS patients (adjusted odds ratio [aOR] = 0.43, 95% CI 0.30-0.62; p < 0.001), with similar results in matched analysis [exact-matched (em) OR = 0.39, 95% CI 0.17-0.89; p < 0.024; groups = 96; unweighted n = 463]. Head-to-head comparison showed that TIPS-only patients were 3.3 times less likely to succumb inpatient versus dialysis-only patients (contrast aOR = 0.31, 95% CI 0.20-0.46; p < 0.001), with similar findings post-matching (emOR = 0.22, 95% CI 0.15-0.33; p < 0.001; groups = 54, unweighted n = 1457)., Conclusions: Contemporary, real-world data reveal that TIPS on its own, and when compared to dialysis, is associated with decreased inpatient mortality when utilized in non-bleeders-HRS patients. Further randomized studies are needed to establish the long-term benefit of TIPS in these patients.

Valentin's rock lizard ( Darevskia valentini ) is suggested to be the parent for several parthenogenetic species (e.g., D. armeniaca , D. bendimahiensis, D. sapphirina , and D. unisexualis ) that evolved through hybridization. Complex evolutionary processes (including reticulate evolution) are occurring within the areas where Valentin's rock lizard coexists with these and other rock lizards. Hence, a detailed biological specification of this species is important for understanding how vertebrates evolve. Valentin's rock lizard is a long-lived (up to 9 years), small diurnal lizard with larger females than males, which is unlike other species of the genus. Their relatively large eggs and early reproduction period, which occurs just after emergence from winter shelters, are adaptations for living in a high elevation climate (higher than 2 000 m a.s.l.). Their body temperatures (31-32 °С) are comparable to body temperatures of rock lizards living in milder climates, though female body temperature is more dependent on substrate temperature and basking due to their lower activity than that found in males. Population density fluctuates from several individuals to several hundred per hectare and is not affected by parthenogen coexistence, although hybrids do occur in sexually biased populations where males are more common than females. The male home range is larger than that of females, though these home ranges broadly overlap. Prey is not limited in the mountain meadows and Valentin's rock lizards feed on a great variety of arthropods. Infanticide occurs in high-density populations.

According to the synthesis of 30 years of multidisciplinary studies, parthenogenetic species of rock lizards of genus Darevskia were formed as a result of different combination patterns of interspecific hybridization of the four bisexual parental species: Darevskia raddei , D. mixta , D. valentini , and D. portschinskii . In particular, D. portschinskii and D. raddei are considered as the parental species for the parthenogenetic species D. rostombekowi . Here for the first time, we present the result of comparative immunocytochemical study of primary spermatocyte nuclei spreads from the leptotene to diplotene stages of meiotic prophase I in two species: D. portschinskii and D. raddei . We observed similar chromosome lengths for both synaptonemal complex (SC) karyotypes as well as a similar number of crossing over sites. However, unexpected differences in the number and distribution of anti-centromere antibody (ACA) foci were detected in the SC structure of bivalents of the two species. In all examined D. portschinskii spermatocyte nuclei, one immunostained centromere focus was detected per SC bivalent. In contrast, in almost every studied D. raddei nuclei we identified three to nine SCs with additional immunostained ACA foci per SC bivalent. Thus, the obtained results allow us to identify species-specific karyotype features, previously not been detected using conventional mitotic chromosome analysis. Presumably the additional centromere foci are result of epigenetic chromatin modifications. We assume that this characteristic of the D. raddei karyotype could represent useful marker for the future studies of parthenogenetic species hybrid karyotypes related to D. raddei ., Competing Interests: The authors declare that they have no competing interests.

Folding of proteins and nucleic acids involves a diffusive search over a multidimensional conformational energy landscape for the minimal-energy structure. When examining the projection of conformational motions onto a one-dimensional reaction coordinate, as done in most experiments, the diffusion coefficient D is generally position dependent. However, it has proven challenging to measure such position-dependence experimentally. We investigated the position-dependence of D in the folding of DNA hairpins as a simple model system in two ways: first, by analyzing the round-trip time to return to a given extension in constant-force extension trajectories measured by force spectroscopy, and second, by analyzing the fall time required to reach a given extension in force jump measurements. These methods yielded conflicting results: the fall time implied a fairly constant D, but the round-trip time implied variations of over an order of magnitude. Comparison of experiments with computational simulations revealed that both methods were strongly affected by experimental artifacts inherent to force spectroscopy measurements, which obscured the intrinsic position-dependence of D. Lastly, we applied Kramers's theory to the kinetics of hairpins with energy barriers located at different positions along the hairpin stem, as a crude probe of D at different stem positions, and we found that D did not vary much as the barrier was moved along the reaction coordinate. This work underlines the difficulties faced when trying to deduce position-dependent diffusion coefficients from experimental folding trajectories., (Copyright © 2018 Biophysical Society. All rights reserved.)

Knowing whether triploid hybrids resulting from natural hybridization of parthenogenetic and bisexual species are fertile is crucial for understanding the mechanisms of reticulate evolution in rock lizards. Here, using males of the bisexual diploid rock lizard species Darevskia raddei nairensis and Darevskia valentini and a triploid hybrid male Darevskia unisexualis × Darevskia valentini , we performed karyotyping and comparative immunocytochemistry of chromosome synapsis and investigated the distribution of RAD51 and MLH1 foci in spread spermatocyte nuclei in meiotic prophase I. Three chromosome sets were found to occur in cell nuclei in the D. unisexualis × D. valentini hybrid, two originating from a parthenogenetic D. unisexualis female and one from the D. valentini male. Despite this distorted chromosome synapsis and incomplete double-strand breaks repair in meiotic prophase I, the number of mismatch repair foci in the triploid hybrid was enough to pass through both meiotic divisions. The defects in synapsis and repair did not arrest meiosis or spermatogenesis. Numerous abnormal mature spermatids were observed in the testes of the studied hybrid., Competing Interests: The authors declare no conflict of interest.

Single-molecule force spectroscopy (SMFS) provides detailed insight into the mechanical (un)folding pathways and structural stability of membrane proteins. So far, SMFS could only be applied to membrane proteins embedded in native or synthetic membranes adsorbed to solid supports. This adsorption causes experimental limitations and raises the question to what extent the support influences the results obtained by SMFS. Therefore, we introduce here SMFS from native purple membrane freely spanning across nanopores. We show that correct analysis of the SMFS data requires extending the worm-like chain model, which describes the mechanical stretching of a polypeptide, by the cubic extension model, which describes the bending of a purple membrane exposed to mechanical stress. This new experimental and theoretical approach allows to characterize the stepwise (un)folding of the membrane protein bacteriorhodopsin and to assign the stability of single and grouped secondary structures. The (un)folding and stability of bacteriorhodopsin shows no significant difference between freely spanning and directly supported purple membranes. Importantly, the novel experimental SMFS setup opens an avenue to characterize any protein from freely spanning cellular or synthetic membranes.