Comparative study of convection characteristics for a system with deformable interface based on the Navier-Stokes and Oberbeck-Boussinesq equations.

The right choice of the appropriate mathematical model is crucial for evaluating the physical plausibility of modelling results. The issue of the correct application of the classical Boussinesq approximation for studying the heat and mass transfer in fluidic systems with a deformable boundary is a subject of scientific discussions despite the good agreement of numerous theoretical and numerical results obtained within the convection models based on the Oberbeck-Boussinesq equations with the data of physical experiments and observations. A comparative analysis of the results of numerical simulations in the framework of two-sided models based on the Navier-Stokes equations, and their Boussinesq approximation, is performed in the context of a convection problem in a locally heated two-phase system with a deformable interface. It is demonstrated that the application of the standard Boussinesq approximation allows one to give a consistent description of the effect of interface deformations on combined buoyant-thermocapillary driven fluid motions. This article is part of the theme issue 'New trends in pattern formation and nonlinear dynamics of extended systems'.

CD30 expression in neoplastic T cells of follicular T cell lymphoma is a helpful diagnostic tool in the differential diagnosis of Hodgkin lymphoma.

Follicular T cell lymphoma is derived from follicular T-helper cells. In many cases, neoplastic T cells form rosettes around Hodgkin-Reed-Sternberg-like cells, which can lead to the misdiagnosis of classical Hodgkin lymphoma. The aim of the present study was to obtain a better understanding of this rosetting phenomenon and to recognize features that are helpful in the differential diagnosis of classical Hodgkin lymphoma. Sixteen mostly elderly follicular T cell lymphoma patients (mean 66 years) were analyzed. Fifteen of the 16 follicular T cell lymphoma cases presented with Hodgkin-Reed-Sternberg-like cells, which were CD20-positive in 27% of the cases and Epstein-Barr virus-infected in nearly all cases. Frequently, the immunophenotype of rosetting neoplastic T cells differed from the bulk neoplastic cells with less numerous T-follicular helper cell markers expressed, suggesting a modulation of T-follicular helper cell marker expression in the neoplastic T cells. In 75% of the cases, variable CD30 expression was encountered in the neoplastic T cells, likely reflecting an activation state in these cells. Hodgkin-Reed-Sternberg-like cells were positive for CCL17, and follicular T cell lymphoma tumor cells expressed its receptor CCR4 at variable intensity, thus potentially explaining the phenomenon of the tumor cells' rosetting around Hodgkin-Reed-Sternberg-like cells. In summary, this study confirms the presence of Hodgkin-Reed-Sternberg-like cells in a high number of cases of follicular T cell lymphoma, suggesting that Hodgkin-Reed-Sternberg-like cells may contribute to the development of this lymphoma. Hodgkin-Reed-Sternberg-like cells in follicular T cell lymphoma cannot reliably be differentiated from the Hodgkin-Reed-Sternberg cells of classical Hodgkin lymphoma based on their immunophenotype. In contrast, demonstration of a T-follicular helper cell phenotype with CD10 and frequent CD30 expression in the neoplastic T cell population can help to establish the diagnosis of follicular T cell lymphoma, and may even indicate CD30 as a therapeutic target for these patients.

Triple Priority: TB/HIV Co-Infection and Treatment Outcomes among Key Populations in The Kyrgyz Republic: A National Cohort Study (2018-2022).

Background: Improving tuberculosis (TB) care in key populations is an operational research priority in the Kyrgyz Republic. Here, we describe the characteristics of TB/HIV co-infected individuals, their affiliations with key country-wide population groups, and their TB treatment outcomes. Methods: This was a cohort study using national programmatic data (2018-2022). The key population groups included people with increased exposure to TB, limited access to TB services, and increased risk of acquiring TB. Results: Among 693 individuals with TB/HIV co-infection, the majority (58%) of individuals were from two regions of the Kyrgyz Republic (Chui and Bishkek). Eighty-four percent (84%) individuals had one or more affiliations to eight key population groups, with 49% of the individuals affiliated to ≥2 groups and 92% of the individuals were on both antiretroviral treatment and cotrimoxazole preventive therapy. Overall, 406 (59%) of the individuals had successful outcomes and 287 (41%) of the individuals had unsuccessful outcomes. Unsuccessful outcomes increased from 36% (n-39) with TB/HIV alone to 47% (n-86) with affiliations to ≥3 key population groups (P-0.03). Unsuccessful outcomes were associated with co-morbidities (diabetes mellitus and hepatitis B/C), migration, alcohol use, and extrapulmonary TB. Conclusions: For a long time, people with TB/HIV co-infection have been recognized as a "double priority". Affiliation to key populations accentuates their status to "triple priority". We advocate for increased attention and equity towards these populations.

Contact Tracing and Tuberculosis Preventive Therapy for Household Child Contacts of Pulmonary Tuberculosis Patients in the Kyrgyz Republic: How Well Are We Doing?

Early identification, screening and investigation for tuberculosis (TB), and provision of TB preventive therapy (TPT), reduces risk of TB among child household contacts of pulmonary TB patients (index patients). A cohort study was conducted to describe the care cascade and timeliness of contact tracing and TPT initiation among child household contacts (aged < 15 years) of index patients initiated on TB treatment in Bishkek, the Kyrgyz Republic during October 2021-September 2022. In the register, information on the number of child household contacts was available for 153 (18%) of 873 index patients. Of 297 child household contacts identified, data were available for 285, of whom 261 (92%) were screened for TB. More than 50% were screened after 1 month of the index patient initiating TB treatment. TB was diagnosed in 23/285 (9%, 95% CI: 6-13%) children. Of 238 TB-free children, 130 (55%) were eligible for TPT. Of the latter, 64 (49%) were initiated on TPT, of whom 52 (81%) completed TPT. While TPT completion was excellent, there was deficiency in contact identification, timely screening and TPT initiation. Thus, healthcare providers should diligently request and record details of child household contacts, adhere to contact tracing timelines and counsel caregivers regarding TPT.

Discharge Outcomes of Severely Sick Patients Hospitalized with Multidrug-Resistant Tuberculosis, Comorbidities, and Serious Adverse Events in Kyrgyz Republic, 2020-2022.

Patients with multidrug-resistant tuberculosis (MDR-TB) who have comorbidities, complications, and experience serious adverse events (SAEs) are at substantial risk of having unfavorable hospital outcomes. We assessed characteristics and discharge outcomes of 138 MDR-TB patients hospitalized in the National Referral Center of Bishkek, Kyrgyz Republic, from January 2020 to August 2022. The main clinical characteristics included pulmonary complications (23%), malnutrition (33%), severe anemia (17%), diabetes mellitus (13%), viral hepatitis B and C (5%), and HIV infection (3%). Of those patients, 95% were successfully managed and discharged from hospital. Seven patients had unfavorable discharge outcomes (three patients died and four had a worsened clinical condition). Comorbidities (diabetes, and/or HIV), severe anemia, pulmonary complications, cardiovascular disorders, alcohol abuse, and SAEs were associated with unfavorable discharge outcomes. Sixty-five percent of the patients had SAEs, with electrolyte imbalance (25%), gastrointestinal disease (18%), hepatotoxicity (16%), and anemia (14%) being the most frequent. Successful resolution occurred in 91% of patients with SAEs. In summary, our study documented that sick patients who were hospitalized with MDR-TB were well managed and had good hospital discharge outcomes, despite the fact that they had comorbidities, complications, and SAEs. This information should assist in the referral and management of such patients in the future.

Strengthening the Operational Research Capacity of National Tuberculosis Control Programs: Necessity or Luxury?

'How to get research into practice: first get practice into research [...].

Chamber Protection of Zinc with Ethylhexanoic Acid.

Chamber protection is a promising and quickly developing method of vapor-phase protection of metals against atmospheric corrosion by inhibitors. It was shown that chamber treatment with 2-ethylhexanoic acid (EHA) efficiently inhibits the initiation of zinc corrosion. The optimum conditions (temperature and duration) of zinc treatment with vapors of this compound were determined. If these conditions are met, adsorption films of EHA with thicknesses up to 100 nm are formed on the metal surface. It was found that their protective properties increase during the first day as zinc is exposed to air after chamber treatment. The anticorrosive action of adsorption films is due both to the surface being shielded from the corrosive environment and to the inhibition of corrosion processes on the active surface of the metal. Corrosion inhibition was caused by the ability of EHA to convert zinc to the passive state and inhibit its local anionic depassivation.

The Trend, Characteristics and Treatment Outcomes in Patients with Tuberculosis Undergoing Thoracic Surgery in the Kyrgyz Republic between 2017 and 2021.

Surgery has played an important role in managing complicated tuberculosis in former Soviet Union countries, including the Kyrgyz Republic. However, published information is limited. This study aimed to document the trend, characteristics and outcomes of tuberculosis patients who underwent thoracic surgery, using routinely collected data. Between 2017 and 2021, 4-7% of tuberculosis patients in the Kyrgyz Republic underwent thoracic surgery in two centres in Bishkek and Osh. In 2021, case records were retrieved in 264 (78%) of 340 patients undergoing thoracic surgery in the country. The most common indications for surgery were pleural exudate/empyema in 127 (44%) and tuberculoma in 83 (32%). Most patients (73%) underwent surgery within 30 days of starting TB treatment. Two-thirds of patients underwent radical surgery, and surgical outcomes were excellent in 99% of patients with one death. Post-operatively, 63 (23%) patients had no TB detected by the histology, with the two most common specified conditions being lung cancer and pulmonary hydatid disease. TB treatment was stopped in these patients. Of the 201 patients with confirmed TB after surgery, TB-treatment success was documented in 163 (81%), died/failure/lost to follow-up in 10 (5%) and not evaluated in 28 (14%). This study shows that thoracic surgery is feasible, safe and effective in the routine programme setting. Recommendations are made to strengthen referral and monitoring systems.

Delays in Treatment Initiation and Treatment Outcomes in Patients with Tuberculosis in the Kyrgyz Republic: Are There Differences between Migrants and Non-Migrants?

Migrants are at increased risk of developing tuberculosis (TB) and have poor treatment outcomes. The National TB program (NTP) of the Kyrgyz Republic recognizes two types of migrants: internal (intra-country) and external (inter-country) migrants. This cohort study compared the characteristics, timeliness of diagnosis and treatment initiation, and treatment outcomes of TB patients (internal migrant vs. external migrant vs. non-migrant) identified during treatment in the country in 2021. The TB treatment register and treatment cards of 5114 patients (156 internal, 430 external, and 4528 non-migrants) were reviewed. Risk factors (unemployment, smoking, alcohol use, and homelessness) were higher (p-value < 0.001) in internal (84%) than in external migrants (66%) and non-migrants (43%). The median delay in seeking care post-symptom onset was longer (p-value= 0.03) in external (30 days) than in internal migrants (21 days) and non-migrants (25 days). Successful treatment outcomes for drug-sensitive TB were higher in internal (89%, p-value = 0.012) and external migrants (86%, p-value = 0.001) than in non-migrants (78%). Internal and external migrants should be separately considered with respect to TB care and monitoring under the NTP. Success rates seem to be high in migrants, but our findings may be biased, as migrants with poor healthcare access may remain undetected and untreated and have undocumented poor outcomes.

Quality of Electronic TB Register Data Compared with Paper-Based Records in the Kyrgyz Republic.

This study evaluated the effectiveness of an electronic system for managing individuals with drug-sensitive pulmonary tuberculosis in the Kyrgyz Republic. This cohort study used programmatic data. The study included people registered on the paper-based system in 2019 and 302 people registered on both the electronic and the paper-based systems between June 2021 and May 2022. The data from the 302 individuals were used to assess the completeness of each form of record and the concordance of the electronic record with the paper-based system. This study showed that for most variables, the completeness and concordance were 85.3-93.0% and were lowest for nonmandatory fields such as medication side effects (26.8% vs. 13.6%). No significant difference was observed in the time taken from symptom onset to diagnosis and treatment initiation between the two systems. However, the electronic system had a significantly higher percentage of subjects who initiated treatment on the day of diagnosis (80.3% vs. 57.1%). The proportion with successful outcomes was similar in both groups, but the electronic system had a significantly lower proportion of individuals with outcomes that were not evaluated or recorded (4.8% vs. 14.3%, p < 0.001). This study highlights the potential advantages and gaps associated with implementing an electronic TB register system for improving records.

Electronic and steric effects controlling monomer-dimer self-assembly in 6H-1,4-diazepinoporphyrazines: an experimental and theoretical study.

A series of 5,7-disubstituted 1,4-diazepinoporphyrazinato magnesium(II) and nickel(II) complexes, including two novel compounds, were obtained by metal-templated macrocyclization. A combination of X-ray diffraction, 1H NMR, UV-vis, and electrochemical analyses allowed us to study their tendency towards H-type dimerization and trace the influence of structural and solvation factors on dimer stability. Based on the physicochemical and theoretical DFT calculation data, it was found that the main binding forces between 6H-1,4-diazepinoporphyrazine decks in the dimers were efficient π-π donor-acceptor interactions induced by the interdeck C-H⋯N hydrogen bonds. Furthermore, the metal-ligand (Pz2- â†’ M2+) electronic interactions have a key influence on the π-π stacking of the porphyrazine cores. It was shown that the displacement of the metal ion out of the macrocycle plane induced by coordinating agents can trigger the dissociation of the dimer, since the resulting enhancement of the donor-acceptor electronic interaction between the metal ion and the π-system of the ligand leads to a subsequent weakening of the π-π stacking of the porphyrazine cores. The TD-DFT calculations predicted the non-degeneracy of the HOMO-1 → LUMO and HOMO → LUMO+1 transitions in the 6H-1,4-diazepinoporphyrazine H-dimers, which explains the Q-band splitting in their UV-vis spectra.

Mutual Effect of Components of Protective Films Applied on Copper and Brass from Octadecylamine and 1,2,3-Benzotriazole Vapors.

It has been shown by a set of corrosion, electrochemical and physical methods that a chamber corrosion inhibitor that consists of a mixture of octadecylamine (ODA) and benzotriazole (BTA) efficiently protects copper and brass from atmospheric corrosion and can be used for the temporary protection of metal items. The optimum temperatures of treatment with the ODA + BTA mixed inhibitor is 120 °C for brass and 100 °C for copper. One-hour treatment in ODA + BTA vapors at these temperatures results in the formation of nanosized adsorption films on the surface of these metals. These films stabilize the passive state and provide efficient temporary protection of metal items. The ODA + BTA inhibitor is superior to its components in terms of protective aftereffect. Our analysis of the mutual effect of BTA and ODA indicated that they show an antagonism of protective action on copper, but there is also a synergistic enhancement in the case of brass. Electrochemical impedance spectroscopy studies demonstrate that the inhibitors in question mainly act by using a blocking mechanism on copper and brass. Chamber treatment of the metals studied in vapors of the ODA + BTA mixture resulted in a noticeable hydrophobization of the copper surface and an insignificant effect on the brass surface. Chamber treatment of copper samples with artificially created polymodal roughness made it possible to obtain a superhydrophobic surface.

Structuring of Surface Films Formed on Magnesium in Hot Chlorobenzotriazole Vapors.

Chamberprotection of metals from atmospheric corrosion is a variety of vapor-phase inhibition. It is based on the effect of adsorption films formed in the vapors of low-volatile corrosion inhibitors at elevated temperatures. The paper analyzes the specific features of the chamber protection of a magnesium alloy with chlorobenzotriazole. It has been found that the protective properties of surface films formed in hot vapors of this compound increase upon exposure of the metal to air. The processes of structuring of protective films that occur in this case have been studied by a set of corrosion, electrochemical and physical methods. It has been shown that chamber treatment of the alloy is accompanied by chlorobenzotriazole adsorption and uniform thickening of the surface oxide-hydroxide layer. In this case, the corrosion processes slow down by a factor of up to 10. Prolonged exposure of the samples in air after the chamber treatment results in additional oxidation of magnesium and hydroxylation of the oxide. However, the oxide-hydroxide layer does not grow on the entire surface, but as separate islets. Such a change in the structure of the surface films results in an additional 10-fold increase in the corrosion resistance of the magnesium alloy.

A Hydrogen-Bromate Flow Battery as a Rechargeable Chemical Power Source.

The hydrogen-bromate flow battery represents one of the promising variants for hybrid power sources. Its membrane-electrode assembly (MEA) combines a hydrogen gas diffusion anode and a porous flow-through cathode where bromate reduction takes place from its acidized aqueous solution: BrO3− + 6 H+ + 6 e− = Br− + 3 H2O (*). The process of electric current generation occurs on the basis of the overall reaction: 3 H2 + BrO3− = Br− + 3 H2O (**), which has been studied in previous publications. Until this work, it has been unknown whether this device is able to function as a rechargeable power source. This means that the bromide anion, Br−, should be electrooxidized into the bromate anion, BrO3−, in the course of the charging stage inside the same cell under strongly acidic conditions, while until now this process has only been carried out in neutral or alkaline solutions with specially designed anode materials. In this study, we have demonstrated that processes (*) and (**) can be performed in a cyclic manner, i.e., as a series of charge and discharge stages with the use of MEA: H2, Freidenberg H23C8 Pt-C/GP-IEM 103/Sigracet 39AA, HBr + H2SO4; square cross-section of 4 cm2 surface area, under an alternating galvanostatic mode at a current density of 75 mA/cm2. The coulombic, voltaic and energy efficiencies of the flow battery under a cyclic regime, as well as the absorption spectra of the catholyte, were measured during its operation. The total amount of Br-containing compounds penetrating through the membrane into the anode space was also determined.

9-12 months short treatment for patients with MDR-TB increases treatment success in Kyrgyzstan.

INTRODUCTION: MDR/RR-TB is a growing problem in Kyrgyzstan. In 2005, the country introduced standard or individualized treatment for 20-24 months. Because of poor treatment outcomes, in 2017 a short treatment with strict eligibility criteria was introduced. The aim of this study was to compare characteristics and treatment outcomes of MDR/RR-TB patients receiving short (9-12 months) treatment in 2017 with those receiving standard or individualized (20-24 months) treatment in 2016/2017. METHODOLOGY: A comparative cohort study using routine programmatic data. Characteristics, sputum culture conversion and treatment outcomes were compared between those on short treatment with those on standard/individualized treatment using the chi-square test, crude and adjusted risk ratios (RR and aRR). RESULTS: The study included 274, 82 and 132 patients on standard, individualized and short treatment, respectively. There were more females, fewer migrants/homeless and unemployed and more new TB patients on short treatment compared with the other two groups. A favorable outcome (cure and treatment completed) was significantly higher in short treatment patients (83%) compared with those on standard (50%) or individualized (59%) treatment (p < 0.001). There was higher 1-month sputum culture conversion with short treatment (35%) compared with the other two groups (19% and 24%, p < 0.05). Short treatment (aRR 1.6, 1.4-1.8), female gender (aRR 1.2, 1.1-1.4), not being homeless (aRR 12.9, 4.5-17.3) and having new TB (aRR 1.3, 1.0-1.5) were independently associated with a favorable outcome. CONCLUSIONS: The treatment success was higher in selected MDR-TB patients given short treatment in Kyrgyzstan: this regimen should be scaled-up to all MDR-TB patients.

Mutual Effects of Components of Protective Films Applied on Steel in Octadecylamine and 1,2,3-Benzotriazole Vapors.

In this work, we used a combination of corrosion, electrochemical, and physical methods to determine the properties of nanoscale films obtained by treatment with octadecylamine (ODA), benzotriazole (BTA) vapors, and their mixtures at elevated temperatures. The mixture of ODA + BTA surpasses its components in protective aftereffect, but an analysis of their mutual effects shows that there is antagonism between them. Electrochemical impedance spectroscopy data indicate that the protection of steel by a mixture of ODA + BTA and its components is characterized by a mixed blocking activation mechanism. The processing of steel in hot vapors of the ODA + BTA mixture leads to hydrophobization of the surface and super-hydrophobization if a polymodal surface is created on the steel before processing in vapors.

Synthesis and characterization of heteroleptic rare earth double-decker complexes involving tetradiazepinoporphyrazine and phthalocyanine macrocycles.

Reaction of (2,3,9,10,16,17,23,24-octabutylphthalocyaninato)lanthanide(iii) acetylacetonates (BuPcLn(acac), 1a-c, Ln = Lu (a), Eu (b), La (c)) with a tetrakis(5,7-bis(4-tert-butylphenyl)-6H-1,4-diazepino)[2,3-b,g,l,q]porphyrazine ligand (tBuPhDzPzH2, 2) produced sandwich compounds (tBuPhDzPz)Ln(BuPc) (3a-c), which represent the first heteroleptic double-deckers incorporating both Pc and DzPz decks. A combination of high-resolution mass spectrometry, UV-Vis/NIR, MCD, and 1H NMR spectroscopy, and square-wave voltammetry provided unambiguous characterization of target complexes 3 indicating that their spectral and electrochemical properties are generally intermediate with respect to their homoleptic relatives. Based on the data of solution-state 1H-1H NMR (COSY, NOESY) correlation spectroscopy supported by DFT calculations, a dimerization tendency of compounds 3 proportional to the Ln(iii) ion size was found. The spectroelectrochemical study of 3 and the corresponding homoleptic double-deckers revealed a pronounced tendency to aggregation of the one-electron oxidized forms of DzPz-containing double-decker complexes compared to homoleptic Pc2Ln compounds.

Who is doing worse? Retrospective cross-sectional study of TB key population treatment outcomes in Kyrgyzstan (2015-2017).

INTRODUCTION: Tuberculosis (TB) is a global public health problem. The incidence of TB is especially high among TB key populations, such as the homeless, people who use drugs, prisoners, and migrants. The study aimed to assess the associations between affiliation to TB key populations and treatment outcome. METHODOLOGY: This retrospective cross-sectional study used data extracted from the National TB Registry of Kyrgyzstan for the region of Chuy (including the city of Bishkek) for 2015-2017. Descriptive statistics was used to summarize the data. Logistic regression was used to assess the associations. RESULTS: The study included 1,526 patients among whom more than half (52.5%) fell into the youngest group (18-35 years old). Migrants were the most highly represented group comprising 67.8% of all TB key populations. Men (63.0%) and patients with pulmonary TB (83.0%) prevailed in the cohort. The proportions of patients who had completed the treatment were high among all the key populations. Logistic regression was used to assess the association between affiliation to a certain TB key population and the TB treatment outcome. Patients who belonged to more than one TB key population were found to have the highest risk of unsuccessful TB treatment outcomes, both in the region of Chuy (OR = 9.9, 95% CI 2.0-48.1, p = 0.04) and the city of Bishkek (OR = 24.9, 95% CI 7.2-86.4, p < 0.001). CONCLUSION: The homeless, people who use drugs, ex-prisoners, and TB patients who belonged to more than one TB key population were found to have higher risks of unsuccessful TB treatment outcome in comparison to migrants.

Tuberculosis in key populations in Tajikistan - a snapshot in 2017.

INTRODUCTION: WHO End TB Strategy aims at achieving targets of 90% mortality reduction and 80% reduction in tuberculosis (TB) incidence by 2030, recommending better addressing TB and multidrug-resistant TB (MDR-TB) issues in key populations. AIM: The study aimed at having a snapshot of the epidemiological characteristics of the key populations among the new TB patients, registered in Tajikistan during 2017. METHODOLOGY: A cross-sectional study was conducted, using official TB registration data for all new TB case notification in Tajikistan in 2017. RESULTS: The key population included 1,029 (19.8%) patients among all 5,182 new TB cases registered in 2017. The following selected sub-populations were identified: migrant workers - 728 (70.7%), diabetics - 162 (15.7%), HIV-positive - 138 (13.4%), heavy drinkers - 74 (7.2%), drug users - 50 (4.8%), ex-prisoners - 50 (4.8%), and homeless - 9 (0.9%). Among the key population, 307 (29.8%) patients were smear-positive, 145 (14.1%) were drug-sensitive and 116 (11.3%) had MonoDR/MDR-TB. Time to treatment initiation for smear-positive cases was ≤ 5 days for 303 (98.7%) patients. Being a key population was inversely related to gender (female) (OR = 0.25, 95% CI (0.21, 0.29)) and population type (rural) (OR = 0.64, 95% CI (0.55, 0.74)). CONCLUSION: Among the key population the identified overlaps of selected sub-populations would enable more efficiently reaching the certain groups. TB case detection at PHC levels needs to be targeted for improved rates for key population detection. In the key population sub-group of migrant workers' special migration destinations are recommended to be explored and find out possible associations with drug resistance.