Search

Abstract Cognitive symptoms persisting beyond the acute phase of COVID-19 infection are commonly described for up to 2 years after infection. The relationship between cognitive performance, in particular episodic memory processes observed chronically after infection, and cytokine levels in the acute phase of COVID-19 has not yet been identified in humans. To determine whether the levels of cytokines IL1β, IL-6 and TNFα secreted in the acute phase of SARS-CoV-2 infection are associated and predict verbal and visuospatial episodic memory performance in humans 6 to 9 months and 12 to 15 months post-infection. The associations and predictive value of the concentration of cytokines measured in acute phase (IL-1β, IL-6, TNFα) from plasma samples of N = 33 hospitalized COVID-19 patients (mean age 61 years, 39–78, 65% in intensive care) in relation to their verbal and visuospatial episodic memory performance measured at 6–9 months and 12–15 months post-infection were analyzed. To do this, we used Spearman correlations and generalised linear mixed models. IL-1β levels were associated with verbal episodic memory total recall scores 6–9 months post-infection. At 12–15 months post-infection IL-6 predicted verbal episodic memory score. This study demonstrated that the severity of inflammatory reaction at acute phase of SARS-CoV-2 infection predicts verbal episodic memory performance in the long-term post-infection.

Abstract Background Folate (vitamin B9) occurs naturally mainly as tetrahydrofolate (THF), methyl-tetrahydrofolate (M-THF), and formyl-tetrahydrofolate (F-THF), and as dietary synthetic form (folic acid). While folate auxotrophy and prototrophy are known for several gut microbes, the specific folate forms produced by gut prototrophs and their impact on gut auxotrophs and microbiota remain unexplored. Methods Here, we quantified by UHPLC-FL/UV folate produced by six predicted gut prototrophs (Marvinbryantia formatexigens DSM 14469, Blautia hydrogenotrophica 10507 T , Blautia producta DSM 14466, Bacteroides caccae DSM 19024, Bacteroides ovatus DSM 1896, and Bacteroides thetaiotaomicron DSM 2079 T) and investigated the impact of different folate forms and doses (50 and 200 µg/l) on the growth and metabolism of the gut auxotroph Roseburia intestinalis in pure cultures and during fecal anaerobic batch fermentations (48 h, 37 °C) of five healthy adults. Results Our results confirmed the production of folate by all six gut strains, in the range from 15.3 ng/ml to 205.4 ng/ml. Different folate forms were detected, with THF ranging from 12.8 to 41.4 ng/ml and 5-MTHF ranging from 0.2 to 113.3 ng/ml, and being detected in all strains. Natural folate forms, in contrast to folic acid, promoted the growth and metabolism of the auxotroph R. intestinalis L1-82, with dose-dependent effects. During fecal batch fermentations, folate forms at both levels had no detectable effect on total bacteria concentration, on gut community composition and metabolic activity and on Roseburia spp. abundance, compared to the control without folate addition. Conclusions Our study demonstrates for the first time in vitro the production of different natural folate forms by predicted gut prototrophs and the stimulation on the growth of the folate auxotrophic butyrate-producing R. intestinalis L1-82. Surprisingly, folate did not impact fecal fermentations. Our data suggest that the dietary folate forms at the tested levels may only have limited effects, if any, on the human gut microbiota in vivo.

Abstract Structural deformation modifies the bandgap, exciton fine structure and phonon energy of semiconductors, providing an additional knob to control their optical properties. The impact can be exploited in colloidal semiconductor quantum dots (QDs), wherein structural stresses can be imposed in three dimensions while defect formation is suppressed by controlling surface growth kinetics. Yet, the control over the structural deformation of QDs free from optically active defects has not been reached. Here, we demonstrate strain-graded CdSe-ZnSe core-shell QDs with compositionally abrupt interface by the coherent pseudomorphic heteroepitaxy. Resulting QDs tolerate mutual elastic deformation of varying magnitudes at the interface with high structural fidelity, allowing for spectrally stable and pure emission of photons at accelerated rates with near unity luminescence efficiency. We capitalize on the asymmetric strain effect together with the quantum confinement effect to expand emission envelope of QDs spanning the entire visible region and exemplify their use in photonic applications.

Abstract Background Previous retrospective research has shown that maintaining prone positioning (PP) for an average of 40 h is associated with an increase of survival rates in intubated patients with COVID-19-related acute respiratory distress syndrome (ARDS). This study aims to determine whether a cumulative PP duration of more than 32 h during the first 2 days of intensive care unit (ICU) admission is associated with increased survival compared to a cumulative PP duration of 32 h or less. Methods This study is an ancillary analysis from a previous large international observational study involving intubated patients placed in PP in the first 48 h of ICU admission in 149 ICUs across France, Belgium and Switzerland. Given that PP is recommended for a 16-h daily duration, intensive PP was defined as a cumulated duration of more than 32 h during the first 48 h, whereas standard PP was defined as a duration equal to or less than 32 h. Patients were followed-up for 90 days. The primary outcome was mortality at day 60. An Inverse Probability Censoring Weighting (IPCW) Cox model including a target emulation trial method was used to analyze the data. Results Out of 2137 intubated patients, 753 were placed in PP during the first 48 h of ICU admission. The intensive PP group (n = 79) had a median PP duration of 36 h, while standard PP group (n = 674) had a median of 16 h during the first 48 h. Sixty-day mortality rate in the intensive PP group was 39.2% compared to 38.7% in the standard PP group (p = 0.93). Twenty-eight-day and 90-day mortality as well as the ventilator-free days until day 28 were similar in both groups. After IPCW, there was no significant difference in mortality at day 60 between the two-study groups (HR 0.95 [0.52–1.74], p = 0.87 and HR 1.1 [0.77–1.57], p = 0.61 in complete case analysis or in multiple imputation analysis, respectively). Conclusions This secondary analysis of a large multicenter European cohort of intubated patients with ARDS due to COVID-19 found that intensive PP during the first 48 h did not provide a survival benefit compared to standard PP.

Abstract Stress in early life can affect the progeny and increase the risk to develop psychiatric and cardiometabolic diseases across generations. The cross-generational effects of early life stress have been modeled in mice and demonstrated to be associated with epigenetic factors in the germline. While stress is known to affect gut microbial features, whether its effects can persist across life and be passed to the progeny is not well defined. Here we show that early postnatal stress in mice shifts the fecal microbial composition (binary Jaccard index) throughout life, including abundance of eight amplicon sequencing variants (ASVs). Further effects on fecal microbial composition, structure (weighted Jaccard index), and abundance of 16 ASVs are detected in the progeny across two generations. These effects are not accompanied by changes in bacterial metabolites in any generation. These results suggest that changes in the fecal microbial community induced by early life traumatic stress can be perpetuated from exposed parent to the offspring.

Abstract Background Prolonged intensive care unit (ICU) stay is associated with physical, cognitive, and psychological disabilities. The impact of baseline frailty on long-stay ICU patients remains uncertain. This study aims to investigate how baseline frailty influences mortality and post-ICU disability 6 months after critical illness in long-stay ICU patients. Methods In this retrospective cohort study, we assessed patients hospitalized for ≥ 7 days in the ICU between May 2018 and May 2021, following them for up to 6 months or until death. Based on the Clinical Frailty Scale (CFS) at ICU admissions, patients were categorized as frail (CFS ≥ 5), pre-frail (CFS 3–4) and non-frail (CFS 1–2). Kaplan–Meier curves and a multivariate Cox model were used to examine the association between frailty and mortality. At the 6 month follow-up, we assessed psychological, physical, cognitive outcomes, and health-related quality of life (QoL) using descriptive statistics and linear regressions. Results We enrolled 531 patients, of which 178 (33.6%) were frail, 200 (37.6%) pre-frail and 153 (28.8%) non-frail. Frail patients were older, had more comorbidities, and greater disease severity at ICU admission. At 6 months, frail patients presented higher mortality rates than pre-frail and non-frail patients (34.3% (61/178) vs. 21% (42/200) vs. 13.1% (20/153) respectively, p

During the maintenance of private vehicles, a stream of consumer waste is generated in the form of containers with engine oil residues. When choosing methods for handling such waste, it is necessary to have quantitative indicators of the tare weight and the volume of engine oil remaining after use. Containers contaminated with motor oils during disposal, neutralization and disposal due to the emission of oil residues create increased risks of man-made impact on environmental objects. The purpose of the study is to determine the volume of motor oil remaining after emptying under various conditions. Viscosity, temperature, runoff angle of engine oil was taken into account as changing conditions. Laboratory studies made it possible to establish that when disposing containers made of HDPE (from 1 to 30 liters), in which engine oil was placed, the waste may contain from 1.5 to 15% of oil products. The smaller the tare volume, the higher the percentage of oil product residues in relation to the tare weight. It is proposed to use K 1 indicators to assess the emission of oil products from containers during its disposal, which allows quantifying the volume of engine oil that can enter the environment during disposal or disposal.

Introduction/Purpose: Akin osteotomy is a surgical technique commonly used in conjunction with osteotomies of the first metatarsal for correction of hallux valgus (HV) deformity. The main indication for an Akin osteotomy is the presence of hallux valgus interphalangeus (HVIF), defined as a HVIF angle >10º. Given that distal osteotomies can change the tendon vector forces, we hypothesize that in a patient with a mobile medial column, an isolated akin osteotomy could improve proximally some radiologic parameters of HV. The purpose of this study was to evaluate whether the isolated Akin osteotomy is able to correct proximally the intermetatarsal angle (IMA) and hallux valgus angle (HVA) in patients with HV deformity. Methods: Case series of consecutive patients with HV deformity treated with an isolated Akin osteotomy, were included in this study. The indications for this surgery were having a mild HV and overlapping of the hallux with the second toe as the main symptom. Patients with fractures, infections, prior surgeries in the forefoot, and concomitant metatarsal osteotomy or first tarsometatarsal fusion were excluded. Two independent evaluators measured the following parameters pre and post-operatively in anteroposterior(AP) feet x-rays: traditional and modified HVA (the latter defined as angle between the long axis of the 1st metatarsal and a line from the center of the base of the proximal phalanx and the tip of the distal phalanx), IMA, distal metatarsal articular angle (DMAA), and HVIF angle. Paired t-test was performed to compare the radiological parameters pre and post- surgery. The absolute intraclass correlation coefficient (ICC) was used to determine the interobserver agreement. P< 0.05 was considered significant. Results: Twenty AP feet x-rays of 12 females and 1 male with a mean age of 44.0 years (range 15 to 85) were included in the final analysis. The preoperative mean and standard deviation (SD) of traditional HVA, modified HVA, IMA, DMAA, and HVIF were 17.0º(7.5), 23.7º(6.5), 11.3º(1.6), 12.6(9.2), and 13.5º(6.0), respectively. The corresponding postoperative values were 9.8º(7.0), 14.4º(7.0), 9.5º(2.0), 11.2º(7.6), and 9.9º(4.9). There was a significant reduction in the traditional HVA (7.2º, p< 0.001), and modified HVA (9.3º, p< 0.001). Also, there was a significant decrease in the IMA (1.8º, p< 0.001), and HVIF (3.5º, p=0.001). Conversely, the DMAA did not change after the osteotomy. The interobserver agreement was moderate to excellent for all radiologic parameters. Conclusion: In this case series, an isolated Akin osteotomy significantly reduced the HVA and IMA. These results challenge the traditional knowledge that Akin only corrects the interphalangeal angle, and could help for a better biomechanical understanding of this deformity, including the effect in proximal correction of distal procedures. An isolated Akin osteotomy could be a plausible alternative for the correction of HV, especially for mild deformities.

Tryptamine, a neuromodulator derived from tryptophan, has been shown to significantly impact the host gut homeostasis through its production by the gut microbiota. However, the characterization of tryptamine-producing gut bacteria remains limited, the factors regulating tryptamine production largely unexplored, and its effects on the rest of the gut microbial community unknown. In this study, we screened 13 intestinal strains closely related to known tryptamine producers, characterized their production kinetics, and evaluated whether tryptophan decarboxylation to tryptamine contributes to acid stress tolerance, as shown in other amino acid-dependent acid tolerance systems. We also examined the impact of tryptamine on the composition and function of four healthy human gut microbiota by conducting 48-h ex vivo fecal batch fermentations. To complement the ex vivo experiments, we tested the effect of tryptamine exposure (range: 0.5–8 mM) on the growth of 18 intestinal strains. We identified tryptamine production in five taxa, i.e., Enterocloster asparagiformis, Blautia hansenii, Clostridium nexile, Clostridium sporogenes, and Ruminococcus gnavus, with R. gnavus DSM 108212 accumulating up to 3.4 mM tryptamine after 48 h. An increased tryptophan concentration led to higher tryptamine production. However, tryptamine production was not promoted at low pH and may not protect cells from acid-induced cellular damage. Exposing gut microbial communities to 2.4 mM tryptamine caused mild changes in gut microbiota function and composition. All donors showed reduced carbohydrate consumption after 5 h, leading to donor-specific alterations of short-chain fatty acids (SCFAs) (i.e., propionate, acetate, butyrate) and branched-chain fatty acids (BCFAs) (i.e., isobutyrate and isovalerate) after 48 h. Tryptamine also induced a mild change of community structure, with a consistent reduction in the phylum Bacteroidota as well as amplicon sequence variants (ASVs) related to the genera Bacteroides, Blautia, and Faecalibacterium. We confirmed the sensitivity of Bacteroides and Faecalibacterium strains in vitro at concentrations of 2 mM and above. Multiple gut commensals remained unaffected when exposed to 8 mM tryptamine. Taken together, our findings demonstrated that intestinal bacteria-derived tryptamine is a bioactive molecule that not only alters host homeostasis locally but also modulates the physiology of gut microbial communities. The specific mechanism through which tryptamine exerts its inhibitory effects on specific gut microbes while leaving others unaffected remains to be elucidated.

Summary: The application of single-cell technologies in clinical nephrology remains elusive. We generated an atlas of transcriptionally defined cell types and cell states of human kidney disease by integrating single-cell signatures reported in the literature with newly generated signatures obtained from 5 patients with acute kidney injury. We used this information to develop kidney-specific cell-level information ExtractoR (K-CLIER), a transfer learning approach specifically tailored to evaluate the role of cell types/states on bulk RNAseq data. We validated the K-CLIER as a reliable computational framework to obtain a dimensionality reduction and to link clinical data with single-cell signatures. By applying K-CLIER on cohorts of patients with different kidney diseases, we identified the most relevant cell types associated with fibrosis and disease progression. This analysis highlighted the central role of altered proximal tubule cells in chronic kidney disease. Our study introduces a new strategy to exploit the power of single-cell technologies toward clinical applications.

Postpartum hypertension (PPHT) is hypertension that persists or develops after delivery and is a frequent cause of readmission, affecting 10% of pregnancies. This interim analysis aims to describe the cohort and to determine the feasibility and acceptance of a home-based telemonitoring management strategy (HBTMS) in PPHT patients. Enrollment at the University Hospital Basel began during the 2020 SARS-CoV-2 pandemic. Maternity-ward patients were screened for preexisting hypertension, hypertensive disorders of pregnancy, and de novo PPHT. In this pragmatic non-randomized prospective trial, the participants chose the HBTMS or standard of care (SOC), which consisted of outpatient hypertension clinic appointments. The HBTMS was a smartphone application or a programmed spreadsheet to report blood pressure (BP), followed by telephone consultations. Three months postpartum, the participants underwent a 24 h BP measurement and a blood, biomarker, and urine analysis. A total of 311 participants were enrolled between 06/20 and 08/23. The mean age was 34 (±5.3) years. The current pregnancy history demonstrated the following (≥1 diagnosis possible): 10% had preexisting hypertension, 27.3% gestational hypertension, 53% preeclampsia (PE), 0.3% eclampsia, 6% HELLP (hemolysis, elevated liver enzymes, and low platelets), and 18.3% de novo PPHT. A family history of cardiovascular disease and PE was reported in 49.5% and 7.5%, respectively. In total, 23.3% were high-risk for PE. A total of 68.5% delivered via c-section, the mean hospitalization was 6.3 days (±3.9), and newborn intrauterine growth restriction occurred in 21%. A total of 99% of the participants chose the HBTMS. This analysis demonstrated that the HBTMS was accepted. This is vital in the immediate postpartum period and pertinent when the exposure of hospital visits should be avoided.

Abstract Background Conflicting findings exist regarding the influence of sex on the development, treatment, course, and outcome of status epilepticus (SE). Our study aimed to investigate sex-related disparities in adult SE patients, focusing on treatment, disease course, and outcome at two Swiss academic medical centers. Methods In this retrospective study, patients treated for SE at two Swiss academic care centers from Basel and Geneva from 2015 to 2021 were included. Primary outcomes were return to premorbid neurologic function, death during hospital stay and at 30 days. Secondary outcomes included characteristics of treatment and disease course. Associations with primary and secondary outcomes were assessed using multivariable logistic regression. Analysis using propensity score matching was performed to account for the imbalances regarding age between men and women. Results Among 762 SE patients, 45.9% were women. No sex-related differences were found between men and women, except for older age and lower frequency of intracranial hemorrhages in women. Compared to men, women had a higher median age (70 vs. 66, p = 0.003), had focal nonconvulsive SE without coma more (34.9% vs. 25.5%; p = 0.005) and SE with motor symptoms less often (52.3% vs. 63.6%, p = 0.002). With longer SE duration (1 day vs. 0.5 days, p = 0.011) and a similar proportion of refractory SE compared to men (36.9% vs. 36.4%, p = 0.898), women were anesthetized and mechanically ventilated less often (30.6% vs. 42%, p = 0.001). Age was associated with all primary outcomes in the unmatched multivariable analyses, but not female sex. In contrast, propensity score-matched multivariable analyses revealed decreased odds for return to premorbid neurologic function for women independent of potential confounders. At hospital discharge, women were sent home less (29.7% vs. 43.7%, p

To produce the health-associated metabolite propionate, gut microbes require vitamin B12 as a cofactor to convert succinate to propionate. B12 is sourced in the human gut from the unabsorbed dietary fraction and in situ microbial production. However, experimental data for B12 production by gut microbes is scarce, especially on their produced B12-analogues. Further, the promotion of propionate production by microbially-produced and dietary B12 is not yet fully understood. Here, we demonstrated B12 production in 6 out of 8 in silico predicted B12-producing bacteria from the human gut. Next, we showed in vitro that B12 produced by Blautia hydrogenotrophica, Marvinbryantia formatexigens, and Blautia producta promoted succinate to propionate conversion of two prevalent B12-auxotrophic gut bacteria, Akkermansia muciniphila and Bacteroides thetaiotaomicron. Finally, we examined the propiogenic effect of commercially available B12-analogues present in the human diet (cyano-B12, adenosyl-B12 and hydroxy-B12) at two doses. The low dose resulted in partial conversion of succinate to propionate for A. muciniphila when grown with adenosyl-B12 (14.6 ± 2.4 mM succinate and 18.7 ± 0.6 mM propionate) and hydroxy-B12 (13.0 ± 1.1 mM and 21.9 ± 1.2 mM), in comparison to cyano-B12 (0.7 ± 0.1 mM and 34.1 ± 0.1 mM). Higher doses of adenosyl-B12 and hydroxy-B12 resulted in significantly more conversion of succinate to propionate in both propionate-producing species, compared to the low dose. B12 analogues have different potential to impact the propionate metabolism of prevalent propionate producers in the gut. These results could contribute to strategies for managing gut disorders associated with decreased propionate production.

Artificial ground freezing during mine shaft construction is a costly endeavor. For effective decision-making in mining operations, it's essential to establish robust control over frozen soil conditions. This control holds paramount importance for ensuring mining safety. After considering the existing approaches to the control of artificial ground freezing, we conducted an analysis of their respective advantages and disadvantages. We introduced two novel principles for controlling the freezing process. These principles mark a substantial advancement from the previously proposed freeze-on-demand concept. Subsequently, we illustrated the practical implementation of these principles by sharing our experience in controlling artificial ground freezing during the construction of two potash mine shafts in the Republic of Belarus. One of the most noteworthy outcomes of this control is the development of innovative technical solutions aimed at enhancing energy efficiency and operational safety in shaft sinking. These solutions encompass interval-based permission for mining activities, facilitating earlier shaft sinking initiation. Another significant solution pertains to swiftly responding, devising, and implementing strategies to counteract groundwater infiltration within one of the frozen soil layers.

Abstract Background Limitations of life-sustaining therapies (LST) practices are frequent and vary among intensive care units (ICUs). However, scarce data were available during the COVID-19 pandemic when ICUs were under intense pressure. We aimed to investigate the prevalence, cumulative incidence, timing, modalities, and factors associated with LST decisions in critically ill COVID-19 patients. Methods We did an ancillary analysis of the European multicentre COVID-ICU study, which collected data from 163 ICUs in France, Belgium and Switzerland. ICU load, a parameter reflecting stress on ICU capacities, was calculated at the patient level using daily ICU bed occupancy data from official country epidemiological reports. Mixed effects logistic regression was used to assess the association of variables with LST limitation decisions. Results Among 4671 severe COVID-19 patients admitted from February 25 to May 4, 2020, the prevalence of in-ICU LST limitations was 14.5%, with a nearly six-fold variability between centres. Overall 28-day cumulative incidence of LST limitations was 12.4%, which occurred at a median of 8 days (3–21). Median ICU load at the patient level was 126%. Age, clinical frailty scale score, and respiratory severity were associated with LST limitations, while ICU load was not. In-ICU death occurred in 74% and 95% of patients, respectively, after LST withholding and withdrawal, while median survival time was 3 days (1–11) after LST limitations. Conclusions In this study, LST limitations frequently preceded death, with a major impact on time of death. In contrast to ICU load, older age, frailty, and the severity of respiratory failure during the first 24 h were the main factors associated with decisions of LST limitations.

Metal(loid) salts were used to treat infectious diseases in the past due to their exceptional biocidal properties at low concentrations. However, the mechanism of their toxicity has yet to be fully elucidated. The production of reactive oxygen species (ROS) has been linked to the toxicity of soft metal(loid)s such as Ag(I), Au(III), As(III), Cd(II), Hg(II), and Te(IV). Nevertheless, few reports have described the direct, or ROS-independent, effects of some of these soft-metal(loid)s on bacteria, including the dismantling of iron–sulfur clusters [4Fe-4S] and the accumulation of porphyrin IX. Here, we used genome-wide genetic, proteomic, and biochemical approaches under anaerobic conditions to evaluate the direct mechanisms of toxicity of these metal(loid)s in Escherichia coli. We found that certain soft-metal(loid)s promote protein aggregation in a ROS-independent manner. This aggregation occurs during translation in the presence of Ag(I), Au(III), Hg(II), or Te(IV) and post-translationally in cells exposed to Cd(II) or As(III). We determined that aggregated proteins were involved in several essential biological processes that could lead to cell death. For instance, several enzymes involved in amino acid biosynthesis were aggregated after soft-metal(loid) exposure, disrupting intracellular amino acid concentration. We also propose a possible mechanism to explain how soft-metal(loid)s act as proteotoxic agents.

Background: Children and adolescents are highly vulnerable to the impact of sustained stressors during developmentally sensitive times. We investigated how demographic characteristics intersect with socioeconomic dimensions to shape the social patterning of quality of life and mental health in children and adolescents, two years into the COVID-19 pandemic. Methods: We used data from the prospective SEROCoV-KIDS cohort study of children and adolescents living in Geneva (Switzerland, 2022). We conducted an intersectional Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy by nesting participants within 48 social strata defined by intersecting sex, age, immigrant background, parental education and financial hardship in Bayesian multilevel logistic models for poor health-related quality of life (HRQoL, measured with PedsQL) and mental health difficulties (measured with the Strengths and Difficulties Questionnaire). Results: Among participants aged 2–17 years, 240/2096 (11.5%, 95%CI 10.1–12.9) had poor HRQoL and 105/2135 (4.9%, 95%CI 4.0–5.9) had mental health difficulties. The predicted proportion of poor HRQoL ranged from 3.4% for 6–11 years old Swiss girls with highly educated parents and no financial hardship to 34.6% for 12–17 years old non-Swiss girls with highly educated parents and financial hardship. Intersectional strata involving adolescents and financial hardship showed substantially worse HRQoL than their counterparts. Between-stratum variations in the predicted frequency of mental health difficulties were limited (range 4.4%–6.5%). Conclusions: We found considerable differences in adverse outcomes across social strata. Our results suggest that, post-pandemic, interventions to address social inequities in HRQoL should focus on specific intersectional strata involving adolescents and families experiencing financial hardship, while those aiming to improve mental health should target all children and adolescents.

The relevance of formulation and numerical implementation of heat and mass transfer model in frozen soils considering mine shaft construction is caused by a number of technological factors and features of artificial ground freezing procedure. Correct calculation of artificial ground freezing for specific practical cases is impossible without taking into account such factors as variable mode of operation of the freeze pipes, presence of two freezing contours, different lengths of the supply pipes of the freeze pipes, heat exchange with the space of the mine shaft of variable depth, formation of cavities in the volume of frozen soils due to soil fallout, heat generation from hardening cement mortar, pore water filtration. These factors are taken into account in the heat and mass transfer model implemented in the specialized program FrozenWall, designed for thermotechnical calculation of artificial ground freezing and developed with the participation of the authors of the paper. The main aim of this work is to describe the improvements made to the algorithms of the FrozenWall software in the course of monitoring the state of the frozen wall on the vertical shafts of potash mines under construction. The objects of study are frozen soils around the potash mine shafts under construction. Methods included experimental temperature measurement in thermal control boreholes, data processing, mathematical modeling of artificial freezing of soils, parameterization of the heat transfer model in soils according to field observations by solving the inverse Stefan problem. Results. In the course of the modernization in the FrozenWall program, the algorithms were added that take into account such technological factors as unstable operation of freeze pipes, presence of two freezing contours, different lengths of the supply pipes inside the freeze pipes, heat exchange with the shaft space, formation of cavities in the volume of frozen soils due to rock outbursts, heat release from hardening cement mortar in the shaft under construction, filtration of pore water. Taking into account these factors, it becomes possible to develop new technical measures aimed at ensuring the efficiency of the construction of mine shafts in difficult hydrogeological conditions and possible emergency situations.

ABSTRACT: Introduction. Polymer-bitumen binders are innovative nano-binders for asphalt concrete pavement. Introduction of a polymer modifier improves the characteristics of bitumen and asphalt concrete. The use of waste tires rubber for bitumen modification is considered to be an environmentally friendly solution, but it is limited due to the poor cosite of rubber with bitumen. Various methods based on activation of the rubber surface, dispersion of rubber to nanosized particles, and thermochemical transformations of rubber into individual organic compounds are known to overcome this limitation. Methods and materials. The method of joint pyrolysis of rubber with oxygen-containing oil under pressure is proposed to be used for converting it into a nanostructural bitumen modifier. The resulting product is studied by the methods of thermogravimetry, NMR-spectroscopy, chromatomasspectrometry, scanning electron microscopy and solubility in toluene. Results and discussion. It has been established that during joint pyrolysis rubber undergoes devulcanization, cracking and dispersion to nanosized particles, and as a result the product becomes compatible with bitumen. Thermochemical reprocessing of waste automobile tires can be considered to be a promising method for the production of a nanostructured bitumen modifier. Conclusion. The use of thermochemical pressure treatment of waste tire rubber in the presence of oxygen-containing oil makes it possible to obtain a nanostructured product compatible with bitumen for further use of the resulting modifier in the production of asphalt concrete.