Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
53 result(s) for "Chudy, M"
Sort by:
Multilayered stable 2D nano-sheets of Ti2NTx MXene: synthesis, characterization, and anticancer activity
Background The biological activity of MXenes has been studied for several years because of their potential biomedical applications; however, investigations have so far been limited to 2D titanium carbides. Although monolayered Ti 2 NT x MXene has been expected to have biological activity, experimental studies revealed significant difficulties due to obstacles to its synthesis, its low stability and its susceptibility to oxidation and decomposition. Results In this paper, we report our theoretical calculations showing the higher likelihood of forming multilayered Ti 2 NT x structures during the preparation process in comparison to single-layered structures. As a result of our experimental work, we successfully synthesized multilayered Ti 2 NT x MXene that was suitable for biological studies by the etching of the Ti 2 AlN MAX phase and further delamination. The biocompatibility of Ti 2 NT x MXene was evaluated in vitro towards human skin malignant melanoma cells, human immortalized keratinocytes, human breast cancer cells, and normal human mammary epithelial cells. Additionally, the potential mode of action of 2D Ti 2 NT x was investigated using reactive oxygen tests as well as SEM observations. Our results indicated that multilayered 2D sheets of Ti 2 NT x showed higher toxicity towards cancerous cell lines in comparison to normal ones. The decrease in cell viabilities was dose-dependent. The generation of reactive oxygen species as well as the internalization of the 2D sheets play a decisive role in the mechanisms of toxicity. Conclusions We have shown that 2D Ti 2 NT x in the form of multilayered nanoflakes exhibits fair stability and can be used for in vitro studies. These results show promise for its future applications in biotechnology and nanomedicine.
Analysis of the quasi-stability of kinematic parameters for manipulators system during the docking process using the Digital Twin approach
This study analyzes the acceleration of the arms of a dual system of manipulators that aim to achieve the minimum distance by mimicking the process of approaching spacecraft that are trying to connect. The research was performed simultaneously on a real model and its digital equivalent, in accordance with the Digital Twin (DT) approach. The obtained acceleration values show, for some set sampling times, read out positions and velocities, separate distributed regions of achievable values. The Digital Twin, Digital Shadow (DS) and Digital Model (DM) approaches have recently shown great progress in development, both in academic studies and at industrial level. Along a very wide range of applications, we propose some important issues related to satellite technologies.
Quantification of the APE2 gene expression level in Candida albicans clinical isolates from patients with diagnosed fungal infections
The production of hydrolytic enzymes is considered a key virulence determinant of Candida albicans . Aminopeptidase 2 (Ape2) facilitates the penetration of C. albicans into the host tissue, by providing free amino acids to support fungal growth and proliferation. The objective of this study was to estimate the APE2 expression profile in C. albicans cells during invasion of the human epithelium. Sixty-one clinical fungal isolates and five reference strains were included in this study. The wild-type APE2 sequence was analyzed by polymerase chain reaction (PCR) amplification using genomic DNA from pathogenic isolates. Amplicons were verified in 1 % agarose gel and visualized by illumination with ultraviolet (UV) light. The APE2 expression levels were analyzed with reverse transcription quantitative real-time PCR (RT-qPCR) and APE2 quantification was normalized against the reference gene in C. albicans cells grown in YEPD and during Caco-2 invasion. The APE2 -specific PCR product band was found in all C. albicans and C. dubliniensis strains, but not in other common pathogenic fungi. APE2 transcript abundance was elevated in the clinical isolates growing on the Caco-2 cell line in comparison to their counterparts grown in YEPD. Our data indicate a potential role for Ape2 in the invasion of epithelial cells. APE2 expression is also strain-specific, and it is not related to isolation site or disease entity.
Long-term prediction intervals of economic time series
We construct long-term prediction intervals for time-aggregated future values of univariate economic time series. We propose computational adjustments of the existing methods to improve coverage probability under a small sample constraint. A pseudo-out-of-sample evaluation shows that our methods perform at least as well as selected alternative methods based on model-implied Bayesian approaches and bootstrapping. Our most successful method yields prediction intervals for eight macroeconomic indicators over a horizon spanning several decades.
The Fiber Content in Fibrous Hemp Depending on Selected Agrotechnical Factors
Relationship between genotypes represented by two fibrous hemp varieties and some agrotechnical factors was investigated in the study. The aim of it was finding how selected factors (three sowing dates, two sowing densities and five harvest dates) influence on total fiber content using osmotic degumming of fibrous plants method for fiber content determination. Results showed 34% higher fiber content for Beniko in comparison to Tygra. It was also shown that fiber content in plants was stronger correlated with harvest date than date of sowing and its density.
Identifying Obstructive Sleep Apnea in At-Risk Youth: An Exploratory Cross-Sectional Study in Adolescents Living With Obesity
Obstructive sleep apnea (OSA) is one of the most common sleep disorders, affecting 1-10 % of children. A key risk factor is elevated body mass index (BMI). This exploratory study aimed to assess OSA prevalence and severity in adolescents living with obesity and explore associations with clinical and metabolic parameters. Adolescents with obesity aged 10-15 years hospitalized for weight management were enrolled. Participants underwent examination including anthropometry, blood pressure, and lipid profile. BMI was evaluated using WHO BMI-for-age z-scores and an internal standard deviation score (SDS). Sleep-disordered breathing was assessed using cardiorespiratory polygraphy. OSA severity was classified by pediatric AASM criteria using the apnea-hypopnea index (AHI). Among 26 adolescents, OSA occurred in 25 (96.2 %). Median AHI was 9.6 (IQR 5.3-19.1); 44 % had severe, 40 % moderate, and 16 % mild OSA. Severe OSA was more frequently observed in boys (p=0.045), who also showed significantly higher BMI z-score, ODI3 and T90 values; (p<0.05). Adolescents with severe OSA had higher body weight and BMI z-scores; (p<0.05). In regression models using BMI SDS, male sex emerged as a borderline predictor of higher AHI (β=9.07; p=0.051), while age and BMI metrics were not significant. Spearman analysis further revealed a moderate positive correlation between BMI z-score and T90 (ρ=0.51, p=0.02). In this exploratory study, OSA was detected in the majority of adolescents living with obesity, though results should be interpreted with caution. Early recognition may support interventions to limit adverse outcomes. Larger polysomnographic studies with control groups are required to confirm prevalence and clarify risk factors.
Design and Validation of Sleep Apnea Risk Assessment (SARA): A Screening Tool for Moderate-to-Severe Obstructive Sleep Apnea
We designed and validated a concise, efficient screening tool, the Sleep Apnea Risk Assessment (SARA), to identify patients at high risk of moderate to-severe obstructive sleep apnea. We conducted a two-phase, multicenter study from September 1, 2018, to October 31, 2023. We created Cohort A (n=221, mean age 50.5±13.0 years, 69.2% male) to design SARA and compared the results with the Epworth Sleepiness Scale, Berlin Questionnaire, Pittsburgh Sleep Quality Index, STOP-Bang, and STOP questionnaires. Cohort B (n=253, mean age 48.0±13.4 years, 75.5% male) served for validation. SARA comprises six variables with the highest accuracy: sleep apnea observed by the bedroom partner (8 points), snoring (5 points), male sex (3 points), age≥50 years (3 points), daytime fatigue (3 points), and body mass index≥30 kg/m (2 points). SARA yielded an area under the receiver operating characteristic curve (AUC) of 0.77 (95% CI: 0.71-0.83) and sensitivity of 87.2% (95% CI: 80.8-92.1) in cohort A at a cut-off score of ≥11 points. Validation in cohort B showed an AUC of 0.79 (95% CI: 0.74-0.84) and a sensitivity of 98% (95% CI: 89.2-95.4). SARA performance significantly outperformed the other questionnaires tested. The SARA is a promising new screening tool for moderate-to-severe obstructive sleep apnea, demonstrating high sensitivity and a strong ROC curve. Further large-scale validation is recommended.
A natural asymptomatic herpes B virus infection in a colony of laboratory brown capuchin monkeys (Cebus apella)
Herpes B virus (BV) infection of macaques persists in the natural host, but is mainly asymptomatic. However, BV can cause fatal disease in humans and in several non-macaque species such as capuchin monkeys (Cebus apella). The BV infection described here in a colony of capuchin monkeys was persistent but asymptomatic. Initially the infection was detected serologically in five out of seven animals. However, using polymerase chain reaction (PCR) developed specifically for BV, we found the virus in all seven clinically healthy animals. It is probable that the infection was transferred from BV-infected macaques housed in different cages but in the same room for several years. We have no evidence to indicate that similar asymptomatic infections may occur in other New World species but the possibility should not be discounted. We recommend that the housing of capuchin monkeys in close proximity to macaques should be avoided and that greater caution should be used when handling capuchin monkeys and possibly other New World species that have been in contact with macaques. All may act as a source of BV infection in humans, hence routine, repeated testing of all primates is essential.
Prevalence of Helicobacter Pylori in Obese Adults: A Literature Review
Obesity is a major health challenge of the 21st century and the number of obese people is increasing worldwide and with it the number of people suffering from obesity-related diseases. The relationship between the presence of obesity and Helicobacter pylori (H. pylori) infection has long been a subject of interest across the literature. The presented review aimed to analyze the prevalence of H. pylori in adults with higher BMI. A literature search was conducted using the electronic databases Scopus, PubMed and Web of science. The term “Helicobacter pylori” was searched with obesity-related keyword combinations. A total of 1.109 records, published in the last 18 years, were identified through the database search. Of these articles, seven were ultimately included in the analysis. Although the studies did not all agree on the same conclusion, most of them have shown that the greater prevalence of H. pylori can be observed in participants with higher BMI, than in normal-weight individuals. A higher prevalence of H. pylori can be observed in obese individuals. However, further research is needed to clearly confirm the BMI-H. pylori relationship.
Positron Annihilation Lifetime Spectroscopy Study of Neutron Irradiated High Temperature Superconductors YBa2Cu3O7-δ for Application in Fusion Facilities
This study focuses on the crystallographic defects introduced by neutron irradiation and the resulting changes of the superconducting properties in the high temperature superconductor YBa 2 Cu 3 O 7-δ . This material is considered to be most promising for magnet systems in future fusion reactors. Two different bulk samples, pure non-doped YBa 2 Cu 3 O 7-δ (YBCO) and multi-seed YBa 2 Cu 3 O 7-δ doped by platinum (MS2F) were studied prior to and after irradiation in the TRIGA MARK II reactor in Vienna. Neutron irradiation is responsible for a significant enhancement of the critical current densities as well as for a reduction in critical temperature. The accumulation of small open volume defects (<0.5 nm) partially causes those changes. These defects were studied by positron annihilation lifetime spectroscopy at room temperature. A high concentration of Cu–O di-vacancies was found in both samples, which increased with neutron fluence. The defect concentration was significantly reduced after a heat treatment.