Long-term stability of sensor arrays remains a major limitation for the practical implementation of electronic nose systems in non-invasive analysis of volatile organic compounds (VOCs) and differentiation of oncological status. Changes in the physicochemical properties of sensing layers during prolonged operation may alter diagnostic parameters and compromise classification consistency. This study evaluated the long-term stability of diagnostically significant parameters obtained from skin gas-profile analysis using a quantum dot-based electronic nose. An eight-sensor piezoelectric electronic nose array based on cadmium sulfide quantum dots with various modifiers was used for skin gas-profile analysis of volunteers and cancer patients. Pair sensitivity parameters (Ai/j) and kinetic sorption parameters derived from chronofrequency responses were assessed by comparing measurements obtained during the pilot study and after two years of sensor operation. Pair sensitivity parameters demonstrated substantial susceptibility to long-term surface degradation and environmental variability, particularly humidity, resulting in pronounced classification drift. In contrast, kinetic sorption parameters exhibited higher temporal stability and lower sensitivity to operating conditions. A correction strategy based on systematic changes in kinetic parameters was developed and applied to compensate for sensor aging effects. The proposed approach reduced classification drift. These findings indicate that correction of long-term sensor drift may help extend the operational lifetime of quantum dot-based electronic nose systems, while kinetic parameters may provide more stable analytical indicators for gas-profile analysis.
Community-acquired urinary tract infections are recognized as one of the most common infections in clinical practice. While Gram-negative flora predominate among urological pathogens, Gram-positive organisms including enterococci may also be involved. This study aimed to determine the prevalence of enterococci (Enterococcus faecalis and En-terococcus faecium) in community-acquired urological infections among patients hospital-ized with urolithiasis. We conducted a retrospective analysis of medical records from five urology departments in Voronezh hospitals spanning 2014-2021. The study cohort com-prised 1,039 patients. Gram-positive organisms accounted for 19.7% to 30.3% of all micro-biological isolates during the observation period. Among uropathogens, Enterococcus fae-calis was identified in 26.4% of cases (2014-2016), 11.7% (2017-2019), and 20.61% (2020-2021), while Enterococcus faecium was less frequently isolated (3.8%-7.26%). Be-tween 2014-2021, we observed increasing resistance rates in Enterococcus faecalis: ampicil-lin resistance rose from 11.35% to 22.22%, gentamicin from 63.1% to 82.02%, vancomycin from 2.1% to 9.1%, and nitrofurantoin from 10.3% to 27.02%. During 2020-2021, we identified 4 Enterococcus faecalis strains demonstrating concurrent resistance to ampicillin, gentamicin and vancomycin, along with 1 Enterococcus faecium strain resistant to four an-tibiotic classes (ampicillin, gentamicin, vancomycin and nitrofurantoin). These findings in-dicate the emergence of enterococcal strains exhibiting multidrug-resistant phenotypes in this patient population.
Despite the organizational and preventive measures, the prevalence of HIV infection continues to increase in Russian Ferderation. The course of the disease is exacerbated by comorbidities such as tuberculosis and chronic hepatitis. This requires a special approach to treatment. The increase in the number of comorbid cases, insufficient screening coverage in risk groups have an impact on the progression of HIV and cause an increase in mortality both in the Russian Federation and Voronezh region over the past decade. Researchers note that many patients died from mycobacterial infections, pneumonia, lymphomas, and other somatic diseases during the first year after diagnosis. The aim of the study . Conduct a comparative analysis of the social, demographic, and medical characteristics, as well as the causes of death, of patients with HIV infection between 2013 and 2023. Materials and methods. A complete sample was selected from medical records of 120 patients who were admitted to the Voronezh Regional AIDS Prevention and Control Center clinic and died during that time period. Statistical analysis was performed using Excel 2019 and included calculation of the Student’s t-test (p<0.05) and Spearman’s rank correlation coefficient. Results and discussion. For the period under study 2013 and 2023 the highest percentage of deaths were observed in the age group from 31 to 40 years old in 2013 and 2023 — 41,7% and 43,3%, respectively, as well as in the age group of 41 to 50 years, which was 23,3% and 43,3%. Both groups were predominantly male, but by 2023 the proportion of young women had increased from 31,7% to 40%, increasing the demographic significance of the problem. Although in the Voronezh region, as well as in the Russian Federation as a whole, HIV infection is mainly transmitted through the sexual contact, our study revealed a high prevalence of patients with experience in places of deprivation of liberty who use drugs and alcohol, highlighting the need for in-depth monitoring and interdisciplinary study of these issues. In the mortality structure, it is necessary to note first of all a significant increase in HIV infection rate, as main cause of death from 11,7 to 25%, an increase in mortality due to external causes from 20% to 25%, and also a decrease in mortality from tuberculosis (TB): from 28,3% to 15%, bacterial infections (extra-hospital bilateral pneumonia and its complications): 11,7% to 8,3%; somatic diseases: 20% to 15%, chronic viral hepatitis C (HCV) in the stage of liver cirrhosis: 8,3% to 6,6%. The negative trend in HIV mortality is due to a number of reasons: improved approaches to clarifying and detailing causes of death have allowed us to better define the role of HIV infection and opportunistic infections (OI). New diagnostic techniques, including telemedicine consultations, could also be introduced. The increase in HIV and AIDS is thought to be related to improved awareness of symptoms and signs of these diseases, leading to earlier diagnosis and lower mortality. However, more research is needed to better understand the causes. Among the somatic diseases that have been the cause of death, an increase in mortality from oncological diseases has been noted (doubling from 3,3% to 6,6%). There were no changes in the mortality rate from cardiovascular disease, but a decrease in mortality from gastrointestinal diseases from 5% to 1,7%. In the group of diseases registered as background pathology, hepatitis C were frequently observed in liver cirrhosis (increase by 11,7% in 2023), gastrointestinal trac diseases (increase by 5% in 2023), nervous system (NS) (increase by 7,3% in 2023) and etc. In contrast to the main group, people living with HIV (PLHIV) between 31 and 50 years of age showed an increase in somatic diseases as a major cause of death (by 2,5%), while the main group decreased by 5%. The increase in mortality from HIV infection and OI from 2013 to 2023 was significantly lower: by 14,3% in the main group and by 2,9% in the age group 31–50 years. The number of deaths from bacterial infections doubled in this group, while the main group showed a decrease. In contrast to the main group, PLHIV at age 31–50 years was observed an increase of somatic diseases (by 2,5%) as the main cause of death while in the main group the same figure decreased by 5%. Conclusion. Thus, this study provides information on the characteristics of PLHIV deaths, which is useful for understanding the mortality structure and designing measures to improve health. Further studies taking into account regional specificities will help to identify trends in the mortality structure and develop effective measures to improve health for people living with HIV
Objective. To demonstrate, using clinical cases, the diagnostic value and the role of ultrasound in assessing metastatic involvement of superficial regional lymph nodes (LN) in patients with cutaneous melanoma. Materials and Methods. Two clinical cases of patients with cutaneous melanoma and regional lymph nodes metastatic involvement are presented. Results of superficial lymph nodes ultrasound were compared with data of radiological methods (contrast-enhanced CT and SPECT) and verified by histopathological examination of surgical specimens. Results and Discussion. Case No.1 demonstrates the classic ultrasound features of lymph-node malignancy: a polycyclic outer contour, loss of corticomedullary differentiation, and a peripheral type of vascularization. In contrast, Case No. 2 shows poor ultrasound features: a rounded LN shape, focal cortical thickening, and hypoechoic areas with a few vascular loci, which are also indicative of secondary involvement. Conclusion. Ultrasound allows to suspect the secondary metastatic lymph nodes changes by the detection of a set of relevant signs in melanoma patients. It may be used as a first-line diagnostic modality to guide further diagnostic workup and treatment planning in patients with cutaneous melanoma.
Relevance. Gonarthrosis is a progressive disease accompanied by constant joint pain and functional limitations significantly reducing the patients’ quality of life and leading to disability. Hyaluronic acid preparations play an important role in the treatment of this pathology. The range of hyaluronic acid preparations is quite wide: they differ in molecular structure, method of synthesis, injection volume, number of procedures, and combination with other active substances. Traditionally, most preparations contain a linear hyaluronic acid molecule. Currently, implants based on cross-linked hyaluronic acid are available on the pharmaceutical market. One of the most advanced processes is cross-linking with BDDE using the innovative patented Crosslinked Hyaluronic Acid Platform (CHAP) technology. Objective. The aim of the study is to assess the effectiveness of cross-linked sodium hyaluronate hydrogel in gonarthrosis treatment. Materials and methods. Twenty patients diagnosed with stage II gonarthrosis have been examined and treated. 2% cross-linked sodium hyaluronate preparation, 3 ml bionic crosslink, was administered to the patients intraarticularly. The patients' condition was assessed using generally accepted scales and questionnaires: before the treatment start, and in seven and in forty days after the drug administration. Results. It has been established that cross-linked sodium hyaluronate does not provide a quick symptomatic effect, but significantly increases all the possible effects in 40 days after its administration. The decrease in pain compared to baseline values was 46%, and the dynamics of the WOMAC index was 36%. 40 days later, 93% of patients observed significant improvement. No complications associated with intra-articular administration of the drug have been revealed. Conclusion. The results of the research indicate the long-term efficacy and safety of cross-linked sodium hyaluronate in the treatment of gonarthrosis.
