Hydrogen sensors based on In2O3 thin films with bimetallic Pt/Pd catalysts on the surface and tin and dysprosium impuri-ties in the bulk

This paper presents the results of studying the characteristics of hydrogen sensors based on thin In2O3 films modified with tin and dysprosium with dispersed double Pt/Pd catalysts deposited on the surface. To control the content of Sn and Dy in the films, an original technology was developed, and ceramic targets were fabricated from powders of the In–Dy–O, Dy–Sn–O, and In–Dy–Sn–O systems synthesized by the sol–gel method. Films of complex composition were obtained by RF magnetron sputtering of the corresponding targets. Structural features of the obtained thin films were studied by Raman spectroscopy. It is shown that various combinations of tin and dysprosium concentrations, as well as the presence of Pt/Pd catalysts on the surface, have a significant effect on the defectiveness of the films and the density of oxygen adsorption centers. As a result, the resistance of sensors in pure air (R0), the activation energies of the temperature dependences of R0, the bending of the energy bands at the grain boundaries of the semiconductor, and the responses to the action of hydrogen in the concentration range of 20–25,000 ppm change. A unique feature of Pt/Pd/ In2O3: Sn (0.5 at%), Dy (4.95 at%) films is their high sensitivity at 20–100 ppm and the absence of signal saturation in the region of high hydrogen concentrations of 5000–25,000 ppm, allowing them to be used to detect H2 in a wide range of concentrations

Polymorphisms of Genes Involved in Endothelial Dysfunction in the Yakuts with COPD and Metabolic Syndrome

The aim of our research was to study the association of the -675 4G/5G (rs1799889) SNP of the SERPINE1 (PAI-1) gene and the Arg353Gln G>A (rs6046) SNP of the F7 gene with metabolic syndrome (MetS) in the Yakuts with COPD. Methods and Results: A molecular-genetic examination was conducted in 200 COPD patients of Yakut ethnicity. The main group (MG) consisted of 100 COPD patients with MetS, the comparison group (CG) included 100 COPD patients without MetS. The distribution of genotypes of studied SNPs was in Hardy-Weinberg equilibrium in all cases. Studying the SERPINE1 -675 4G/5G SNP, we found the prevalence of a 4G allele in MG, compared to CG (OR=1.84, 95% CI 1.23–2.74; χ2=9.06, P=0.003). Incidence of the homozygous 4G/4G mutation was rather high in MG, compared to CG (OR=2.35, 95%CI 1.24–4.44; χ2=9.31, P=0.002). According to our data, the presence of MetS in Yakut patients with COPD has been associated with the carrier of the 4G/4G genotype. Studying the F7 Arg353Gln SNP, we found the prevalence of an Arg253 allele in both groups (0.72 in MG and 0.71 in CG; χ2=0.01, P=0.91). The homozygous Gln353/Gln353 mutant genotype was rare in both groups (0.12 in MG and 0.10 in CG; OR=1.23, 95%CI 0.50–2.99; χ2=0.01, P=0.92). In our study, the F7 Arg353Gln SNP was not associated with protection against MetS in COPD patients

Chelation of Zinc with Biogenic Amino Acids: Description of Properties Using Balaban Index, Assessment of Biological Activity on Spirostomum Ambiguum Cellular Biosensor, Influence on Biofilms and Direct Antibacterial Action

The complexation of biogenic molecules with metals is the widespread strategy in screening for new pharmaceuticals with improved therapeutic and physicochemical properties. This paper demonstrates the possibility of using simple QSAR modeling based on topological descriptors for chelates study. The presence of a relationship between the structure (J) and lipophilic properties (logP) of zinc complexes with amino acids, where two molecules coordinate the central atom through carboxyl oxygen and amino group nitrogen, and thus form a double ring structure, was predicted. Using a cellular biosensor model for Gly, Ala, Met, Val, Phe and their complexes Zn(AA)2, we experimentally confirmed the existence of a direct relationship between logP and biological activity (Ea). The results obtained using topological analysis, Spirotox method and microbiological testing allowed us to assume and prove that the chelate complex of zinc with methionine has the highest activity of inhibiting bacterial biofilms, while in aqueous solutions it does not reveal direct antibacterial effect

Optimization of therapy of type 2 diabetes mellitus with the oral hypoglycemic agent glimepiride

Type 2 diabetes is believed to develop as a result of lowered insulin secretion and insulin resistance leading to hyperglycemia. Sulfonylureas stimulateinsulin secretion and thereby decrease blood glucose level which accounts for their wide application in the treatment of diabetes. However, manyagents of this class produce side effects (increased body mass, hypoglycemia, resistance to therapy, etc.) attributable to excess stimulation of insulinsecretion. Glimepiride is as efficient as traditionally used sulfonylureas but causes a smaller rise in insulin secretion. Sulfonylurea receptors showlower affinity for glimepiride than for glibenclamide. Formation and dissociation of glimepiride-receptor complexes occur faster than those of glibenclamide-receptor complexes. In addition, therapeutic effect of glimepiride was shown to be associated with improved insulin sensitivity. It is concludedthat glimepiride is an efficacious agent for the treatment of type 2 diabetes

Ammonia sensors based on resistive structures M–SnO2:Sb–M

The paper presents a comparison of the responses of sensors to ammonia in continuous heating and thermal cycling modes, and also shows the dependence of the response time of the sensors on the content NH3. Thin films of tin dioxide were obtained using RF magnetron sputtering, and then annealed in air at a temperature of 425°C for 24 hours. In thermal cycling, the temperature of the heating cycle remains constant 400 °C (duration of the heating cycle was 8 s). The temperature of the cooling cycle changes in the range 200 °C – 100 °C, but duration of cooling of the cooling cycle was remained constant of 5 s. It was shown that the thermal cycling mode has several advantages over the constant heating mode. The experiments showed that sensors based on SnO2:Sb have short response times – less than 3 seconds

Pharmacoeconomic analysis of conservative strategy for the treatment of patients with diabetic foot syndrome in Moscow

Aim. To perform cost-effectiveness analysis of prescription of pharmaceutical products and dressing materials and their consumption volume for inandout-patient treatment of diabetic foot syndrome (DFS). To analyse efficacy of the treatment in terms of modern therapeutic standards. Materials and methods. This retrospective study is based on the medical documentation of 139 DM1 and DM2 patients with DFS from differentmedical facilities of Moscow (2007). 72 patients were given general out-patient care by surgeons of city polyclinics, 50 ones received specialized aidin the regional Diabetic Foot Cabinet. 67 patients were hospitalized: 20 for general care in the department of purulent surgery of a military hospital,27 for specialized care in the department of purulent surgery of a city hospital, 20 for high-technology care in the endocrinological clinic of the FirstMoscow State Medical University. Results. Therapeutic strategy for DFS patients used in the regional Diabetic Foot Cabinet met the current therapeutic standards. General out-patientcare by surgeons of city polyclinics was at variance with the algorithms adopted in this country. Pharmacoeconomic analysis of the spectrum of pharmaceuticalproducts used for in- and out-patient treatment of DFS patients revealed frequent and ungrounded application of drugs whose woundhealing effect remains to be confirmed (pentoxifylline, thioctoic and alpha-lipoic acids). Conclusion. Additional training courses for surgeons of Moscow polyclinics are needed to improve the quality of medical aid to DFS patients. Suchpatients must be referred to regional Diabetic Foot Cabinets. Pentoxifylline, thioctoic and alpha-lipoic acids need to be substituted by pharmaceuticalswith validated therapeutic efficacy

Hydrogen Sensors Based on In₂O₃ Thin Films with Bimetallic Pt/Pd Catalysts on the Surface and Tin and Dysprosium Impurities in the Bulk

This paper presents the results of studying the characteristics of hydrogen sensors based on thin In2O3 films modified with tin and dysprosium with dispersed double Pt/Pd catalysts deposited on the surface. To control the content of Sn and Dy in the films, an original technology was developed, and ceramic targets were fabricated from powders of the In–Dy–O, Dy–Sn–O, and In–Dy–Sn–O systems synthesized by the sol–gel method. Films of complex composition were obtained by RF magnetron sputtering of the corresponding targets. Structural features of the obtained thin films were studied by Raman spectroscopy. It is shown that various combinations of tin and dysprosium concentrations, as well as the presence of Pt/Pd catalysts on the surface, have a significant effect on the defectiveness of the films and the density of oxygen adsorption centers. As a result, the resistance of sensors in pure air (R0), the activation energies of the temperature dependences of R0, the bending of the energy bands at the grain boundaries of the semiconductor, and the responses to the action of hydrogen in the concentration range of 20–25,000 ppm change. A unique feature of Pt/Pd/ In2O3: Sn (0.5 at%), Dy (4.95 at%) films is their high sensitivity at 20–100 ppm and the absence of signal saturation in the region of high hydrogen concentrations of 5000–25,000 ppm, allowing them to be used to detect H2 in a wide range of concentrations