Tribological behaviour of ARC sprayed coatings made of Fe-Cr-B-Al cored wires under the service conditions of the http valve spindles

Досліджено трибологічну поведінку електродугових покриттів із ПД системи Fe-Cr-B-Al за робочих умов штоків запірних вентилів ТЕС. Встановлено, що коефіцієнт тертя досліджуваних покриттів за умов сухого тертя та прикладеному навантаженні більше 4 МПа є таким же, як і для сталі ШХ 15. Виявлено, що дані покриття добре працюють у контакті з графітовим ущільненням. Також виявлено позитивний вплив просочування електродугових покриттів синтетичними оливами для умов роботи сухого тертя, що зумовлено їхньою структурою, і не залежить від системи легування.The tribological behavior of arc sprayed coatings made of Fe-Cr-B-Al cored wires has been investigated under the service conditions of the heat power plant valve spindle. The arc sprayed coatings have a characteristic lamella structure, lamellas being the solidified droplets separated by oxide films of different nature and thickness, the grinded surface of which is the composite –in the matrix from steel lamellas the particles of oxide phases are available, therefore the structure of such coatings causes their special tribological behavior. It was investigated, that in the dry friction condition under loading of 2 MPa, the friction coefficient of the ШХ 15 steel is lower than for the coating obtained from Fe-Cr-B-Al cored wire, and is equal to 0.32, and under loading more than 4 MPa it equals 0.42. It testifies that under loading less than 2 MPa the tribological properties of ШХ 15 steel are better, however with the increase of loading this phenomenon is not available. It was suggested to investigate the influence of solid lubricant CaF2 on the friction coefficient behavior of arc sprayed coatings made of Fe-Cr-B-Al cored wires. The adding of the CaF2 powder to the mixture of cored wires provides the change of the coating friction coefficient and its behavior is similar to the behavior of the ШХ 15 steel friction coefficient, but, nevertheless, the nominal values are too high and under loading – 5 MPa it equals 0.4. It was found that under the dry friction condition when the loading was 5-6 MPa the temperature on the surface of the coating equals 250-300ºС and the oxide films are formed there. The oxide film is formed on the surface on steel – less-alloyed Cr, on coatings – much-alloyed Cr. In the friction tests these oxide films break and form abrasive particles which cause the significant abrasive wear of both, coating and counterbody – 3X13 steel. It was found that such coatings have very low values of friction coefficients – 0.12-0.15 under conditions of the dry friction in contact with counterbody with built-in graphite. Moreover, with the increase of loading from 2 to 10 MPa the friction coefficient decreases. It was explained by the fact that arc sprayed coatings have on its surface pores and the graphite is accumulated in them during friction and then it forms the boundary friction film on the friction surface. It was found that during wear resistance tests the ШХ15 steel wears the least but its counterdody made of 3X13 steel is subject to significant wear under the dry friction condition, therefore the total wear of this friction pair is higher than for the arc sprayed coating. The positive influence of sealing arc sprayed coatings with synthetic oil was revealed too for the dry friction condition. It was determined that sealing of arc sprayed coatings made of Fe-Cr-B-Al cored wires with synthetic oil Synth 5W40 provides the increasing of their wear resistance in 12 times as compared with those made of ШХ 15 steel and in 9 times as compared with unsealed coatings. The sealed arc sprayed coatings made of Fe-Cr-C-Al cored wires provide the increase of their wear resistance in 9 times in comparison with ШХ 15 steel and in 5 times as compared with unsealed coatings. Such influence of sealing coatings with oil on their wear resistance is likely to be caused by their structure which depends on spraying parameters and doesn’t depend on their alloying system

Epidemiology of Mycobacterium tuberculosis lineages and strain clustering within urban and peri-urban settings in Ethiopia

Background Previous work has shown differential predominance of certain Mycobacterium tuberculosis (M. tb) lineages and sub-lineages among different human populations in diverse geographic regions of Ethiopia. Nevertheless, how strain diversity is evolving under the ongoing rapid socio-economic and environmental changes is poorly understood. The present study investigated factors associated with M. tb lineage predominance and rate of strain clustering within urban and peri-urban settings in Ethiopia. Methods Pulmonary Tuberculosis (PTB) and Cervical tuberculous lymphadenitis (TBLN) patients who visited selected health facilities were recruited in the years of 2016 and 2017. A total of 258 M. tb isolates identified from 163 sputa and 95 fine-needle aspirates (FNA) were characterized by spoligotyping and compared with international M.tb spoligotyping patterns registered at the SITVIT2 databases. The molecular data were linked with clinical and demographic data of the patients for further statistical analysis. Results From a total of 258 M. tb isolates, 84 distinct spoligotype patterns that included 58 known Shared International Type (SIT) patterns and 26 new or orphan patterns were identified. The majority of strains belonged to two major M. tb lineages, L3 (35.7%) and L4 (61.6%). The observed high percentage of isolates with shared patterns (n = 200/258) suggested a substantial rate of overall clustering (77.5%). After adjusting for the effect of geographical variations, clustering rate was significantly lower among individuals co-infected with HIV and other concomitant chronic disease. Compared to L4, the adjusted odds ratio and 95% confidence interval (AOR; 95% CI) indicated that infections with L3 M. tb strains were more likely to be associated with TBLN [3.47 (1.45, 8.29)] and TB-HIV co-infection [2.84 (1.61, 5.55)]. Conclusion Despite the observed difference in strain diversity and geographical distribution of M. tb lineages, compared to earlier studies in Ethiopia, the overall rate of strain clustering suggests higher transmission and warrant more detailed investigations into the molecular epidemiology of TB and related factors

Latency Associated Peptide Has In Vitro and In Vivo Immune Effects Independent of TGF-β1

Latency Associated Peptide (LAP) binds TGF-β1, forming a latent complex. Currently, LAP is presumed to function only as a sequestering agent for active TGF-β1. Previous work shows that LAP can induce epithelial cell migration, but effects on leukocytes have not been reported. Because of the multiplicity of immunologic processes in which TGF-β1 plays a role, we hypothesized that LAP could function independently to modulate immune responses. In separate experiments we found that LAP promoted chemotaxis of human monocytes and blocked inflammation in vivo in a murine model of the delayed-type hypersensitivity response (DTHR). These effects did not involve TGF-β1 activity. Further studies revealed that disruption of specific LAP-thrombospondin-1 (TSP-1) interactions prevented LAP-induced responses. The effect of LAP on DTH inhibition depended on IL-10. These data support a novel role for LAP in regulating monocyte trafficking and immune modulation

Network analysis of dairy cattle movement and associations with bovine tuberculosis spread and control in emerging dairy belts of Ethiopia

Background: Dairy cattle movement could be a major risk factor for the spread of bovine tuberculosis (BTB) in emerging dairy belts of Ethiopia. Dairy cattle may be moved between farms over long distances, and hence understanding the route and frequency of the movements is essential to establish the pattern of spread of BTB between farms, which could ultimately help to inform policy makers to design cost effective control strategies. The objective of this study was, therefore, to investigate the network structure of dairy cattle movement and its influence on the transmission and prevalence of BTB in three emerging areas among the Ethiopian dairy belts, namely the cities of Hawassa, Gondar and Mekelle. Methods: A questionnaire survey was conducted in 278 farms to collect data on the pattern of dairy cattle movement for the last 5 years (September 2013 to August 2018). Visualization of the network structure and analysis of the relationship between the network patterns and the prevalence of BTB in these regions were made using social network analysis. Results: The cattle movement network structure display both scale free and small world properties implying local clustering with fewer farms being highly connected, at higher risk of infection, with the potential to act as super spreaders of BTB if infected. Farms having a history of cattle movements onto the herds were more likely to be affected by BTB (OR: 2.2) compared to farms not having a link history. Euclidean distance between farms and the batch size of animals moved on were positively correlated with prevalence of BTB. On the other hand, farms having one or more outgoing cattle showed a decrease on the likelihood of BTB infection (OR = 0.57) compared to farms which maintained their cattle. Conclusion: This study showed that the patterns of cattle movement and size of animal moved between farms contributed to the potential for BTB transmission. The few farms with the bulk of transmission potential could be efficiently targeted by control measures aimed at reducing the spread of BTB. The network structure described can also provide the starting point to build and estimate dynamic transmission models for BTB, and other infectious disease

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Tribological characteristics of plasma-electrolyte layers in pairs with steels 45 and U8

Досліджено трибологічну поведінку сталей 45 та У8 у парі із ПЕО шарами, синтезованими на легких сплавах АМг-6 та Д16Т у мінеральній оливі І-20, із додатком до неї дистильованої води та водного розчину гліцерину. Виявили різницю у фрикційній поведінці ПЕО шарів, синтезованих на алюмінієвих сплавах із підвищеним вмістом магнію (АМг-6) та з підвищеним вмістом міді (Д16Т) за контактування із стальними контртілами. Purpose of this work to probe the tribologichnu conduct of PEO glowed, synthesized on the easy alloys of AMg-6 and D16T in the clean mineral olive of I-20, with an appendix to it of the distilled water and water solution of glycerin at a contact from stalyami 45 and U8 . The tribological behavior of steels 45 and Y8 in pairs with PEO layers synthesized on light alloys AMg-6 and D16T in mineral oil I-20 with the application of distilled water and an aqueous solution of glycerin was investigated. They found a difference in the frictional behavior of plasma-electrolyte layers synthesized on aluminum alloys with increased magnesium content (AMg-6) and with an increased copper content (D16T) in contact with steel counterweights. In the case of contact between the plasma-electrolyte layers synthesized on the AMg-6 alloy with the steels under investigation, as a result of tribochemical reactions in the contact zone on the steel surface, a spinel-type oxide layer is synthesized with the general formula FeAl2O4, which protects them from wear by exposure to hydrogen, Loads not exceeding 4 MPa. In the case of contact between the plasma-electrolyte layers synthesized on the D16T alloy, oxygen-free wear of steel counter-bodies occurs and such a contact pair is operable to loads above 10 MPa with a low frictional heating temperature. Investigational tribological behavior of pair of dielectrics – an explorer (ceramics are a metal) glowed on the example of PEO, synthesized on the easy alloys of AMg and D16T in a contact with iron-carbon alloys – steel 45, U8

Anal human papillomavirus (HPV) disagreement by Linear Array compared to SPF10 PCR-DEIA-LiPA25 system in young sexual minority men

Introduction: Young sexual minority men (SMM) bear the greatest burden of anal human papillomavirus (HPV) infections. We assessed anal HPV genotype discordance between the Linear Array (LA) and SPF10 PCR-DEIA-LiPA25 (LiPA25). Methods: Discordance was assessed between LA and LiPA25 using self-collected anal swabs from 120 SMM aged 18-29 who were recruited in 2014-2016. Multiple-type infection was explored as a potential confounder of testing agreement, along with clinical and behavioral factors such as HIV status, syphilis status, incarceration history, health insurance coverage, having 3 or more sex partners in the past 6 months, and co-infection with HPV-16. Results: Significant discordance was found for HPV-6, -11, -16, -31, -42, -54, and -59. Exploratory analyses suggest higher prevalence of genotype discordance in those living with HIV, those with 3 or more sex partners, and those who were positive for 4 or more HPV types. Conclusions: Our results highlight the importance of HPV detection methods which may inform different interpretations of research assessing anal HPV natural history among SMM at highest risk for HPV.</p

Metastases-directed stereotactic body radiotherapy in combination with targeted therapy or immunotherapy: systematic review and consensus recommendations by the EORTC-ESTRO OligoCare consortium.

Stereotactic body radiotherapy (SBRT) for patients with metastatic cancer, especially when characterised by a low tumour burden (ie, oligometastatic disease), receiving targeted therapy or immunotherapy has become a frequently practised and guideline-supported treatment strategy. Despite the increasing use in routine clinical practice, there is little information on the safety of combining SBRT with modern targeted therapy or immunotherapy and a paucity of high-level evidence to guide clinical management. A systematic literature review was performed to identify the toxicity profiles of combined metastases-directed SBRT and targeted therapy or immunotherapy. These results served as the basis for an international Delphi consensus process among 28 interdisciplinary experts who are members of the European Society for Radiotherapy and Oncology (ESTRO) and European Organisation for Research and Treatment of Cancer (EORTC) OligoCare consortium. Consensus was sought about risk mitigation strategies of metastases-directed SBRT combined with targeted therapy or immunotherapy; a potential need for and length of interruption to targeted therapy or immunotherapy around SBRT delivery; and potential adaptations of radiation dose and fractionation. Results of this systematic review and consensus process compile the best available evidence for safe combination of metastases-directed SBRT and targeted therapy or immunotherapy for patients with metastatic or oligometastatic cancer and aim to guide today's clinical practice and the design of future clinical trials