43 research outputs found

    Glucose Oxidase Loading in Ordered Porous Aluminosilicates: Exploring the Potential of Surface Modification for Electrochemical Glucose Sensing

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    Enzymatic electrochemical sensors have become the leading glucose detection technology due to their rapid response, affordability, portability, selectivity, and sensitivity. However, the performance of these sensors is highly dependent on the surface properties of the electrode material used to store glucose oxidase and its ability to retain enzymatic activity under variable environmental conditions. Mesoporous thin films have recently attracted considerable attention as promising candidates for enzyme storage and activity preservation due to their well-defined nanoarchitecture and tunable surface properties. Herein, we systematically compare pathways for the immobilization of glucose oxidase (GOx) and their effectiveness in electrochemical glucose sensing, following modification protocols that lead to the electrostatic attraction (amino functionalization), covalent bonding (aldehyde functionalization), and electrostatic repulsion (oxygen plasma treatment) of the ordered porous aluminosilicate-coated electrodes. By direct comparison using a quartz crystal microbalance, we demonstrate that glucose oxidase can be loaded in a nanoarchitecture with a pore size of ∼50 nm and pore interconnections of ∼35 nm using the native aluminosilicate surface, as well as after amino or aldehyde surface modification, while oxygen plasma exposure of the native surface inhibits glucose oxidase loading. Despite a variety of routes for enzyme loading, quantitative electrochemical glucose sensing between 0 and 20 mM was only possible when the porous surface was functionalized with amino groups, which we relate to the role of surface chemistry in accessing the underlying substrate. Our results highlight the impact of rational surface modification on electrochemical biosensing performance and demonstrate the potential of tailoring porous nanoarchitecture surfaces for biosensing applications

    Improving discrimination of Raman spectra by optimising preprocessing strategies on the basis of the ability to refine the relationship between variance components

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    Discrimination of the samples into predefined groups is the issue at hand in many fields, such as medicine, environmental and forensic studies, etc. Its success strongly depends on the effectiveness of groups separation, which is optimal when the group means are much more distant than the data within the groups, i.e. the variation of the group means is greater than the variation of the data averaged over all groups. The task is particularly demanding for signals (e.g. spectra) as a lot of effort is required to prepare them in a way to uncover interesting features and turn them into more meaningful information that better fits for the purpose of data analysis. The solution can be adequately handled by using preprocessing strategies which should highlight the features relevant for further analysis (e.g. discrimination) by removing unwanted variation, deteriorating effects, such as noise or baseline drift, and standardising the signals. The aim of the research was to develop an automated procedure for optimising the choice of the preprocessing strategy to make it most suitable for discrimination purposes. The authors propose a novel concept to assess the goodness of the preprocessing strategy using the ratio of the between-groups to within-groups variance on the first latent variable derived from regularised MANOVA that is capable of exposing the groups differences for highly multidimensional data. The quest for the best preprocessing strategy was carried out using the grid search and much more efficient genetic algorithm. The adequacy of this novel concept, that remarkably supports the discrimination analysis, was verified through the assessment of the capability of solving two forensic comparison problems - discrimination between differently-aged bloodstains and various car paints described by Raman spectra - using likelihood ratio framework, as a recommended tool for discriminating samples in the forensics

    Preferences and expectations among Polish women regarding prenatal screening

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    Objectives: Patients’ attitudes and expectations of prenatal screening for genetic abnormalities throughout pregnancy are rarely analyzed by researchers as emotions and fears are both important and challenging factors. Prenatal counselling has never been so difficult as we live in the era of detailed ultrasound scans, cell-free fetal DNA and detailed microarray testing. The aim of this study was to investigate Polish women’s attitudes towards screening for chromosomal abnormalities and fetal defects.  Material and methods: The study was a prospective survey conducted among a population of Polish women. An electronic questionnaire regarding prenatal diagnostics was distributed to a total number of 1072 female volunteers.  Results: 1044 patients (97.30%) stated that they were motivated to undergo prenatal diagnostics and would want to be informed about fetal abnormalities. Over 90% of the respondents would want to be informed about serious defects with a high mortality rate (including trisomy 13 or 18). More than half the Polish women (54.83%) stated they were willing to consider terminating pregnancy in the case of a severe abnormality.  Conclusions: Polish women expect prenatal screening. Almost all Polish women would want to be informed about both genetic and anatomical abnormalities and over half of them would consider terminating pregnancy in the case of a severe abnormality. Willingness to learn about a defect increased with average household income, and the statement of a will to terminate pregnancy depended mostly on maternal age and type of fetal abnormality

    Fabrication of High-Aspect Ratio Nanogratings for Phase-based X-ray Imaging

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    Diffractive optical elements such as periodic gratings are fundamental devices in X-ray imaging - a technique that medical, material science and security scans rely upon. Fabrication of such structures with high aspect ratios at the nanoscale creates opportunities to further advance such applications, especially in terms of relaxing X-ray source coherence requirements. This is because typical grating-based X-ray phase imaging techniques (e.g., Talbot self-imaging) require a coherence length of at least one grating period and ideally longer. In this paper, the fabrication challenges in achieving high aspect-ratio nanogratings filled with gold are addressed by a combination of laser interference and nanoimprint lithography, physical vapor deposition, metal assisted chemical etching (MACE), and electroplating. This relatively simple and cost-efficient approach is unlocked by an innovative post-MACE drying step with hexamethyldisilazane, which effectively minimizes the stiction of the nanostructures. The theoretical limits of the approach are discussed and, experimentally, X-ray nanogratings with aspect ratios >40 demonstrated. Finally, their excellent diffractive abilities are shown when exposed to a hard (12.2 keV) monochromatic x-ray beam at a synchrotron facility, and thus potential applicability in phase-based X-ray imaging.Comment: 27 pages, 5 figures in main text, plus supporting informatio

    Knee joint injuries in football players: types of injuries, etiology, diagnostics and prevention

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    Introduction Football stands as the most widely embraced organized sport globally, boasting a staggering participation of over 200 million males and 21 million females officially registered under the auspices of the Fèdèration Internationale de Football Association (FIFA). Knee injuries are one of the most common health issues among soccer players at various levels of expertise. They arise from the intense nature of the game, which requires quick turns, running, jumping, kicking, and sudden changes in direction. These stresses can lead to strains and injuries in the structures of the knee joint, including ligaments, meniscus, tendons, and other soft tissues. This study gathers information about the most common types of knee injuries in soccer players, including situations in which these injuries occur, methods of diagnosis, treatment options, and strategies for injury prevention.  Aim The aim of this study is to gather and analyse the studies about knee injuries in soccer players at various levels of expertise. Materials and Methods Review and summary of research studies available in databases on Google Scholar and PubMed. Databases such as PubMed and Google Scholar were searched using the keywords: ‘soccer knee injuries’, ‘soccer injuries’, ‘ACL tear’, ‘MCL injury’, ‘meniscus injury’, ‘PCL and LCL tear’. Summary Soccer, as a high-contact sport, inherently carries a significant risk of various injuries, particularly to the knees. The prevalence of knee injuries, such as ACL, MCL, and meniscus tears, underscores the importance of effective prevention strategies. Proper warm-ups and specialized preventive exercises, such as those in the FIFA 11+ program, are crucial in reducing the incidence of these injuries. Injuries can severely impact a player's career, leading to long-term health consequences. Therefore, timely and accurate diagnosis, along with appropriate treatment, is essential for recovery and career longevity.&nbsp

    Direct Inhibition of IRF-Dependent Transcriptional Regulatory Mechanisms Associated With Disease

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    Interferon regulatory factors (IRFs) are a family of homologous proteins that regulate the transcription of interferons (IFNs) and IFN-induced gene expression. As such they are important modulating proteins in the Toll-like receptor (TLR) and IFN signaling pathways, which are vital elements of the innate immune system. IRFs have a multi-domain structure, with the N-terminal part acting as a DNA binding domain (DBD) that recognizes a DNA-binding motif similar to the IFN-stimulated response element (ISRE). The C-terminal part contains the IRF-association domain (IAD), with which they can self-associate, bind to IRF family members or interact with other transcription factors. This complex formation is crucial for DNA binding and the commencing of target-gene expression. IRFs bind DNA and exert their activating potential as homo or heterodimers with other IRFs. Moreover, they can form complexes (e.g., with Signal transducers and activators of transcription, STATs) and collaborate with other co-acting transcription factors such as Nuclear factor-κB (NF-κB) and PU.1. In time, more of these IRF co-activating mechanisms have been discovered, which may play a key role in the pathogenesis of many diseases, such as acute and chronic inflammation, autoimmune diseases, and cancer. Detailed knowledge of IRFs structure and activating mechanisms predisposes IRFs as potential targets for inhibition in therapeutic strategies connected to numerous immune system-originated diseases. Until now only indirect IRF modulation has been studied in terms of antiviral response regulation and cancer treatment, using mainly antisense oligonucleotides and siRNA knockdown strategies. However, none of these approaches so far entered clinical trials. Moreover, no direct IRF-inhibitory strategies have been reported. In this review, we summarize current knowledge of the different IRF-mediated transcriptional regulatory mechanisms and how they reflect the diverse functions of IRFs in homeostasis and in TLR and IFN signaling. Moreover, we present IRFs as promising inhibitory targets and propose a novel direct IRF-modulating strategy employing a pipeline approach that combines comparative in silico docking to the IRF-DBD with in vitro validation of IRF inhibition. We hypothesize that our methodology will enable the efficient identification of IRF-specific and pan-IRF inhibitors that can be used for the treatment of IRF-dependent disorders and malignancies

    Spacer-defined intrinsic multiple patterning

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    Periodic nanotube arrays render enhanced functional properties through their interaction with light and matter, but to reach optimal performance for technologically prominent applications, such as wettability or photonics, structural fine-tuning is essential. Nonetheless, a universal and scalable method providing independent dimension control, high aspect ratios, and the prospect of further structural complexity remains unachieved. Here, we answer this need through an atomic layer deposition (ALD)-enabled multiple patterning. Unlike previous methods, the ALD-deposited spacer is applied on the prepatterned target substrate material, serving as an etching mask to generate a multitude of . By concept iteration, we further realize concentric and/or binary nanoarrays in a number of industrially important materials such as silicon, glass, and polymers. To demonstrate the achieved quality and applicability of the structures, we probe how nanotube fine-tuning induces broadband antireflection and present a surface boasting extremely low reflectance of <1% across the wavelength range of 300-1050 nm

    Spectroscopic Identification of Active Sites of Oxygen-Doped Carbon for Selective Oxygen Reduction to Hydrogen Peroxide

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    The electrochemical synthesis of hydrogen peroxide (H2O2) via a two-electron (2 e−) oxygen reduction reaction (ORR) process provides a promising alternative to replace the energy-intensive anthraquinone process. Herein, we develop a facile template-protected strategy to synthesize a highly active quinone-rich porous carbon catalyst for H2O2 electrochemical production. The optimized PCC900 material exhibits remarkable activity and selectivity, of which the onset potential reaches 0.83 V vs. reversible hydrogen electrode in 0.1 M KOH and the H2O2 selectivity is over 95 % in a wide potential range. Comprehensive synchrotron-based near-edge X-ray absorption fine structure (NEXAFS) spectroscopy combined with electrocatalytic characterizations reveals the positive correlation between quinone content and 2 e− ORR performance. The effectiveness of chair-form quinone groups as the most efficient active sites is highlighted by the molecule-mimic strategy and theoretical analysis

    Novel CuInS2 quantum dots as fluorescent probes for bioimaging: synthesis and characterization

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    Wydział FizykiKropki kwantowe (ang. quantum dots, QDs) to półprzewodnikowe nanokryształy o wielkości od 2 do 10 nm, posiadające unikalne właściwości optyczne i elektryczne wynikające z kwantyzacji ruchu nośników ładunku w trzech kierunkach. Celem pracy była synteza wolnych od metali ciężkich kropek kwantowych jako potencjalnych sond fluorescencyjnych do bioobrazowania, ich charakterystyka fizykochemiczna, funkcjonalizacja ligandem specyficznym dla receptora (HER2) nowotworu piersi i ostatecznie weryfikacja właściwości aplikacyjnych otrzymanych sond w obrazowaniu in vitro komórek nowotworowych. Jako fotoaktywny rdzeń wybrano trójskładnikowy półprzewodnik CuInS2. Następnie otoczono go powłoką w postaci ZnS, aby poprawić właściwości optyczne rdzenia. W celu zdyspergowania kropek w wodzie, CuInS2/ZnS QDs posiadające hydrofobowe ligandy zmodyfikowano powierzchniowo poprzez otoczenie ich amfifilowym polimerem. Otrzymane nanokryształy sfunkcjonalizowano peptydem swoistym dla HER2 i ostatecznie wykazano ich skuteczność w obrazowaniu in vitro HER2-pozytywnego raka piersi.Quantum dots (QDs) are size-quantized semiconductor nanocrystals that possess unique optical properties attributed to the quantum confinement effect. The aim of this study was to develop new heavy metal-free QD-based nanoprobes for potential applications in bioimaging. CuInS2 ternary nanocrystals as a core material are proposed. The QDs synthesis, phase transfer, characterization and band gap engineering were the general objectives. Moreover, QDs functionalization with a targeting ligand toward cancer cells was the aim of this work, in order to verify whether they could be useful as a fluorescent tool in cancer cells imaging. First, CuInS2 core QDs were synthesized via a non-injection approach, followed by a ZnS shell introduction. Subsequently, CuInS2/ZnS QDs were successfully transferred into water using an amphiphilic polymer. A HER2 receptor-binding peptide as a targeting ligand was anchored to the nanocrystals surface via diamine spacer. Finally, an imaging experiment was performed revealing that peptide-linked QDs can be a potential tool for HER2-pisitive cancer cells imaging
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