Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Single-crystalline superalloy CMSX-4 is studied in the as-cast state and after heat treatment, with material being taken from turbine blade castings. The effect of the heat treatment on the defect structure of the root area near the selector/root connection is emphasized. Multiscale analysis is performed to correlate results obtained by X-ray topography and positron annihilation lifetime spectroscopy (PALS). Electron microscopy observations were also carried out to characterize the inhomogeneity in dendritic structure. The X-ray topography was used to compare defects of the misorientation nature, occurring in as-cast and treated states. The type and concentration of defects before and after heat treatment in different root areas were determined using the PALS method, which enables voids, mono-vacancies, and dislocations to be taken into account. In this way, differences in the concentration of defects caused by heat treatment are rationalized

STUDYING OF COMORBID PATHOLOGY AT THE 2 TYPES DIABETES AS THE COMPLICATION OF THE METABOLIC SYNDROME

Purpose. To define features of comorbid pathology at patients with a 2 types diabetes, to estimate a possibility of use of indexes of a comorbid pathology in the management of these patients. Materials and methods. Patients with a 2 types diabetes participated in a research. The retrospective analysis of medical records with calculation of indexes of a comorbid pathology for the systems CIRS, Kaplan-Feinstein, Charlson was made. Taking into account the received indexes at patients prognostic indicators of percentage risk of lethality within the next year and 10-year survival were defined. Correlation interrelations between laboratory indicators of components of a metabolic syndrome and values of indexes of a a comorbid pathology are defined. Results. It was defined that in structure of comorbid pathology at the chosen patients diseases of cardiovascular, nervous and genitourinary systems prevail. Besides the specified systems, at women specific gravity of pathology of endocrine system is big. With age the tendency to prevalence of comorbid pathology of the specified systems remains and also the augmentation of average score of indexes of a comorbid pathology on all systems, deterioration in prognostic indicators is taped. Statistically significant direct link between indexes of a comorbid pathology and separate components of a metabolic syndrome, an experience of a disease of patients is also taped

The efficacy and safety of corneal collagen cross-linking in progressive keratoconus with regard to long-term results

Purpose. To evaluate the efficacy and safety of a modified technique of corneal collagen cross-linking in comparison with the standard approach by the nature changes in clinical and morphological parameters of the cornea in the early and longterm postoperative period.Material and methods. The study included two groups of patients: the group 1 consisted of patients operated on for progressive keratoconus in the classical way of corneal collagen cross-linking – 25 individuals (25 eyes), the group 2 – patients treated by the modified cross-linking technique – 36 individuals (36 eyes). Before and after the procedure in the follow-up of 1, 3, 6 and 12 months, all patients underwent an extended ophthalmic examination, including the optical coherence tomography (OCT) of the cornea (Cirrus HD 3000, Carl Zeiss, Germany), the confocal microscopy (Confoscan4, Nidek, Japan).Results. Re-epithelialization of the cornea occurred faster in the group 2. In both investigated groups a significant UCVA increase (from 0.15±0.04 to 0.35±0.07 in the group 1 and 0.13±0.025 to 0.33±0.04 in the group 2) and the BCVA (from 0.3±0.08 to 0.5±0.05 in the group 1 and 0.4±0.04 to 0.87±0.18 in the group 2) was noted in the follow-up period of 6-12 months. After 1 month postoperatively the well-defined linear opacities in the middle and posterior layers of the stroma – the so-called «demarcation lines» or «posterior stromal hazes» appeared during the ophthalmic bio-microscopy as well as in the OCT of cornea in all observed patients. In this period the depth of the «demarcation line» position in the group 1 averaged 252±15.0μm, in the group 2 – 235±10.0μm. The confocal microscopy showed that histomorphological changes were more pronounced in the group 1 within all above-mentioned periods. In the 3-month follow-up in the group 2 a statistically significant reduction in our proposed scoring estimation of all the studied signs, and a maintenance of this trend were detected in the follow-up period after 6 and 12 months, that indicates a more mild and rapid regeneration of cornea after the corneal collagen cross-linking surgery performed according to the modified technique. The endothelial cells density (ECD) remained unchanged in all followup periods in both groups.Conclusions. Thus, a manifestation of positive dynamics in the postoperative UCVA, BCVA and the unchanged ECD in all cases allows to consider both options of corneal collagen crosslinking safe, with a comparable clinical efficacy. However, a more pronounced positive dynamics in the BCVA in the group 2, a milder course of the early postoperative period for patients, consisting in a more rapid completion of the re-epithelialization process, as well as and the availability of adequate and safe level histomorphological changes in the cornea after the cross-linking enable to recommend the modified technique for the treatment of progressive keratoconus

Potential Polyvaccine Based on Microbial IgA1 Protease for Prophylaxis of Bacterial Meningitis

The immunogenic and protective activities of recombinant IgA1 serine protease obtained on the base of the genome DNA of N. meningitidis serogroup B strain H44/76 were studied. A several recombinant proteins of different molecular weights that are based on the full-length primary structure of the enzyme, taking into account the distribution of B- and T-epitopes, also were studied. In experiments on laboratory animals it was shown that a number of tested preparations demonstrate the immunogenic and protective activity to protect mice from lethal challenge with virulent strains of meningococcus serogroups A, B and C, thereby exhibiting polyvaccine properties. The protective role of antibodies against the IgA1 protease was shown when mice were infected by meningococccus serogroup B. The increase in antibodies to the meningococcal IgA1 protease into the blood of rabbits infected with different serotypes of pneumococci has been detected, indicating potential ability of the meningococcal IgA1 protease to generate protection against microbes the virulence of which is caused by IgA1protease

Biocatalytic Method for Producing an Affinity Resin for the Isolation of Immunoglobulins

Affinity chromatography is a widely used technique for antibody isolation. This article presents the successful synthesis of a novel affinity resin with a mutant form of protein A (BsrtA) immobilized on it as a ligand. The key aspect of the described process is the biocatalytic immobilization of the ligand onto the matrix using the sortase A enzyme. Moreover, we used a matrix with primary amino groups without modification, which greatly simplifies the synthesis process. The resulting resin shows a high dynamic binding capacity (up to 50 mg IgG per 1 mL of sorbent). It also demonstrates high tolerance to 0.1 M NaOH treatment and maintains its effectiveness even after 100 binding, elution, and sanitization cycles

Diffuse Reflectance Spectroscopy of the Oral Mucosa: In Vivo Experimental Validation of the Precancerous Lesions Early Detection Possibility

This article is devoted to the experimental validation of the possibility of early detection of precancerous lesions in the oral mucosa in vivo using diffuse reflectance spectroscopy in the wavelength range from 360 to 1000 nm. During the study, a sample of 119 patients with precancerous lesions has been collected and analyzed. As a result of the analysis, the most informative wavelength ranges were determined, in which the maximum differences in the backscattering spectra of lesions and intact tissues were observed, methods for automatic classification of backscattering spectra of the oral mucosa were studied, sensitivity and specificity values, achievable using diffuse reflectance spectroscopy for detecting hyperkeratosis on the tongue ventrolateral mucosa surface and buccal mucosa, were evaluated. As a result of preliminary experimental studies in vivo, the possibility of automatic detection of precancerous lesions of the oral mucosa surface using diffuse reflectance spectroscopy in the wavelength range from 500 to 900 nm with an accuracy of at least 75 percent has been shown