Search Results (125)

The use of widespread and inexpensive clay minerals as adsorptive agents, as well as materials obtained by their chemical modification, can contribute to the solution of the problem of environmental pollution with antibiotics. This review considers the structural features of various natural clay minerals and the effect of these features on their sorption capacity. Based on the analysis of available papers (over the last 15 years, also including some fundamental basics over the last 20–30 years), it has been established that the main property of an antibiotic molecule affecting the ability to be adsorbed by a clay mineral is the hydrophilicity of the organic substance molecule. The leading properties that determine the ability of clays to adsorb antibiotics are the charge and area of their surfaces. The ability of antibiotic molecules to protonate and a partial change in the edge charge of mineral layers is determined by the acidity of the sorption solution. In addition, empirical evidence is provided that the most important factors affecting adsorption are the ionic strength of the sorption solution, the concentration of the adsorbent and adsorbate, and the interaction temperature. The diversity of the composition, structure, and properties of clay minerals allows them to be effective sorbents for a wide range of antibiotics. Full article

A biosensor for the determination of glucose, lactate, ethanol and starch in beverages has been developed using enzymes immobilized by a redox-active gel on a screen-printed electrode. A significant improvement proposed for multichannel biosensors, overcoming stability and sensitivity issues by covalently binding phenazine mediators to a biocompatible protein hydrogel, enhancing the packaging of the enzyme. Glucose oxidase (GOx), alcohol oxidase (AOx) and lactate oxidase (LOx) were used as biological materials, as well as a mixture of GOx with γ-amylase (Am). Redox gels were synthesized from bovine serum albumin (BSA) and phenazine derivatives. It was shown that a neutral red-based redox gel combined with single-walled carbon nanotubes is more promising than other substrates for enzyme immobilization. The lower limit of quantification for glucose, ethanol, lactate and starch using these systems is 0.035 mM, 2.3 mM, 15 mM and 2 mg/L, respectively. Biosensors were used to analyze the content of these substances in alcoholic, kvass and fermentation mass. Statistical analysis of the results showed that the values of glucose, ethanol, lactic acid and starch determined using biosensors and obtained by reference methods differ insignificantly. A set of biosensors developed on the basis of specifically selected enzymes is effective for controlling biotechnological processes and can be used as an alternative to classical analytical methods. Full article

Viruses exhibit significantly greater diversity than cellular organisms, posing a complex challenge to their taxonomic classification. While primary sequences may diverge considerably, protein functional domains can maintain conserved 3D structures throughout evolution. Consequently, structural homology of viral proteins can reveal deep taxonomic relationships, overcoming limitations inherent in sequence-based methods. In this work, we introduce MPACT (Multimetric Pairwise Comparison Tool), an integrated tool that utilizes both sequence- and structure-based metrics. The program incorporates five metrics: sequence identity, similarity, maximum likelihood distance, TM-score, and 3Di-character similarity. MPACT generates heatmaps and distance trees to visualize viral relationships across multiple levels, enabling users to substantiate viral taxa demarcation. Taxa delineation can be achieved by specifying appropriate score cutoffs for each metric, facilitating the definition of viral groups, and storing their corresponding sequence data. By analyzing diverse viral datasets spanning various levels of divergence, we demonstrate MPACT’s capability to reveal viral relationships, even among distantly related taxa. This tool provides a comprehensive approach to assist viral classification, exceeding the current methods by integrating multiple metrics and uncovering deeper evolutionary connections. Full article

Background: Long COVID is characterized by persistent symptoms following acute SARS-CoV-2 infection. This study aims to evaluate immune system markers, including antigen-specific antibodies, B cell subsets, and Th2-related cytokines, in individuals with long COVID and to investigate their potential impact on the development of this condition. Methods: We analyzed blood plasma from 63 individuals diagnosed with long COVID based on clinical presentation and 47 healthy individuals with COVID-19 history but no clinical symptoms. Antigen-specific IgG antibodies were measured using commercial ELISA kits. Lymphocyte subpopulations were assessed via flow cytometry and a gating strategy based on CD27 and CD38. Th2 cytokines (IL-4, IL-5, IL-13) were quantified using the xMAP multiplex assay. Results: We noted no significant differences in IgG levels between groups. Notably, individuals with long COVID demonstrated a higher percentage of naive mature B cells (CD27−CD38+), while transitional (CD27−CD38+++) and double-negative (DN, CD27−CD38-) cells were significantly reduced. Elevated levels of IL-5 and IL-13 were observed in long COVID patients. Classification analysis revealed that the percentage of transitional B cells (CD27−CD38+++) was a strong predictor of long COVID. Conclusions: Our findings highlight alterations in B cell dynamics among individuals with long COVID, which may contribute to autoimmune processes. Full article

This article explores systemic inflammatory response syndrome (SIRS), thromboinflammation, and septic shock in fetuses and neonates, offering a comprehensive examination of their pathophysiology, diagnostic criteria, and clinical implications. It identifies SIRS as an exaggerated response to external stress, disrupting the balance between inflammation and adaptive mechanisms, driven by cytokines such as TNF-α and IL-1. The fetal inflammatory response syndrome (FIRS), a subset of SIRS, is noted for its role in adverse neonatal outcomes, including organ damage, inflammation, and long-term developmental disorders. The article discusses the extensive effects of FIRS on critical systems, including the blood, lungs, central nervous system, and kidneys. It highlights the challenges in diagnosing and managing septic shock in neonates, focusing on the relationship between inflammation and the hemostatic system. Additionally, the paper points out recent advancements, such as the convergent model of coagulation and emerging biomarkers like microRNAs for early detection. Despite this progress, gaps remain in understanding the molecular mechanisms underlying these conditions and in developing effective therapeutic strategies. This highlights the necessity for targeted research to mitigate the morbidity and mortality associated with septic shock in neonates. Full article

Recent advancements have expanded the applications of fiber-optic distributed acoustic sensors (DAS), including their use in monitoring the acoustic activity of insects, which can be either harmful or beneficial to agriculture. Previous studies have demonstrated the capability of DAS to record and analyze insect-generated acoustic signals in real-world conditions; however, these studies primarily involved large insect colonies. In this work, a fiber-optic DAS is used for the first time to record the sounds produced by a single insect under controlled laboratory conditions. This was achieved using an optimized and cost-effective experimental setup designed and assembled, including a specially developed and manufactured sensing element. The results demonstrate that the fiber-optic DAS effectively captures the acoustic signals of the Madagascar hissing cockroach (Gromphadorhina portentosa), including both the mechanical interactions of the insect with the optical fiber and the characteristic hissing sound produced in response to external stimulation. Full article

John Cottingham argues that traditional university modules in the philosophy of religion take us into a ‘very abstract domain that is often far removed from religion as it actually operates in the life of the believer’. This paper makes four moves based on Cottingham. First, it argues that the application of Ludwig Wittgenstein’s methods supports and facilitates a shift to the anthropological in the philosophy of religion (as evidenced in the work of Mikel Burley). Second, literature is examined as a tool for doing the philosophy of religion, following Danielle Moyal-Sharrock’s notion of the literary text as surveyable representation. Three works are investigated, namely Silence by Shūshaku Endō, The Brothers Karamazov by Fyodor Dostoevsky, and the Gospel of John. It is argued that, far from being merely illustrative of religion, story is (in its widest sense) constitutive of belief. Third, it is shown how Wittgenstein’s remarks on mysticism in the Tractatus Logico-Philosophicus can be read as a transmutation of literary writing that creates a non-abstract mysticism of the world. Wittgenstein’s remarks are placed in dialogue with Angelus Silesius’s poetry and Leo Tolstoy’s The Gospel in Brief. Fourth, the relevance of Wittgenstein to the current debate on cultural Christianity is brought out. Philosophers of religion must take leave of the abstract, if only to return to it and to view it differently. Wittgenstein’s thought is too important to ignore in this venture. Full article

This narrative review summarizes the available literature on the association between In Vitro Fertilization (IVF) treatments and thrombosis, focusing on epidemiology and pathophysiology. Thrombosis is a rare IVF-related complication, with an incidence of approximately 0.2%, dramatically increased by ovarian hyperstimulation syndrome (OHSS). Arterial thrombosis, primarily associated with OHSS, is a rare and early event, while venous thrombosis, although more common, remains a rare complication of IVF. Venous thrombosis often affects the upper body. The thrombotic risk is higher during the first trimester of pregnancy obtained through IVF. This review discusses the impact of risk factors such as OHSS, thrombophilia, obesity, advanced maternal age, and polycystic ovarian syndrome, which predispose women to thromboembolic events during and after IVF stimulation. Full article

Myocardial ischemia-reperfusion injury increases myocardial microvascular permeability, leading to enhanced microvascular filtration and interstitial fluid accumulation that is associated with greater microvascular obstruction and inadequate myocardial perfusion. A burst of reactive oxygen species and inflammatory mediators during reperfusion causes myosin light chain kinase (MLCK)-dependent endothelial hyperpermeability, which is considered a preventable cause of reperfusion injury. In the present study, a single intravenous injection of MLCK peptide inhibitor PIK7 (2.5 mg/kg or 40 mg/kg) was found to suppress the vascular hyperpermeability caused by ischemia/reperfusion injury in an in vivo rat model. The antiedemic effect of PIK7 is transient and ceases within 90 min of reperfusion. The early no-reflow detected for the first time after 30 min ischemia in this model of myocardial infarction reduces the area accessible for PIK7. Electron microscopy has shown membrane-bound blebs of endotheliocytes, which partially or completely obturate the capillary lumen, and few capillaries with signs of intercellular gap formation in samples obtained from the center of the early no-reflow zone in control and PIK7-injected rats. Co-injection of PIK7 with NO donor sodium nitroprusside (SNP) increases blood flow in the zone of early no-reflow, while reducing the increased vascular permeability caused by SNP. Full article

Urea, the end product of protein breakdown, is crucial for detecting chronic conditions. Normal urine urea levels range from 110 to 390 mM. This project aims to create a biosensor for rapid urea monitoring using urease immobilized on bovine serum albumin (BSA), safranin (SAF), and fullerene. The biosensor features a modified graphite paste electrode with a bionanocomposite, a silver chloride reference electrode, and a potentiostat set at +0.275 V. The sensor accurately measures urea concentrations from 68 to 410 mM in urine. Full article

Polycyclic aromatic hydrocarbons (PAHs) are a major scientific challenge due to their profound impact on public and environmental health. Therefore, studying ways to detoxify PAHs is important. In this research, the adsorption ability of bentonite modified with five surfactants, including amphoteric (cocoamphodiacetate disodium and sodium cocoiminodipropionate) and nonionic (lauramine oxide, cocamide diethanolamine, and alkylpolyglucoside) substances for the adsorption of high-molecular benzo(a)pyrene and low-molecular naphthalene from the PAH group was studied. The bentonite and bentonite-based organoclays were characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The results showed that the maximum adsorption of benzo(a)pyrene by organoclays increased compared with the initial mineral. The adsorption of benzo(a)pyrene is higher than that of naphthalene. The adsorption process of benzo(a)pyrene by bentonite and organoclays is predominantly monolayer, as it is better described by the Langmuir model (R² 0.77–0.98), while naphthalene is predominantly multilayer, described by the Freundlich model (R² 0.86–0.96). According to the effectiveness of sorption capacities of organoclays—including the degree of sorption, Langmuir and Freundlich constants, the value of maximum adsorption, Gibbs free energy, and the index of favorability of the adsorption process—the most effective modification was found. For the adsorption of benzo(a)pyrene the best was cocoamphodiacetate disodium, and for naphthalene it was sodium cocoiminodipropionate. Full article

Standard single-mode telecommunication optical fiber is still one of the most popular in distributed acoustic sensing. Understanding the acoustic, mechanical and optical features of various fibers available currently can lead to a better optimization of distributed acoustic sensors, cost reduction and adaptation for specific needs. In this paper, a study of the performances of seven fibers with different coatings and production methods in a distributed acoustic sensor setup is presented. The main results include the amplitude–frequency characteristic for each of the investigated fibers in the range of acoustic frequencies from 100 to 7000 Hz. A single-mode fiber fabricated using the modified chemical vapor deposition technique together with a polyimide coating has shown the best sensitivity to acoustic events in the investigated range of frequencies. All of this allows us to both compare the studied specialty fibers with the standard single-mode fiber and choose the most suitable fiber for a specific application, providing an enhancement for the performance of distributed acoustic sensors and better adaptation for the newly aroused potential applications. Full article

For many decades, natural and modified clay minerals have been used as adsorbents to clean up aquatic and soil ecosystems contaminated with organic and inorganic pollutants. In this study, organoclays based on bentonite and various amphoteric and nonionic surfactants were synthesized and tested as effective sorbents for lead ions. The maximum values of R were obtained when describing the sorption processes using the Langmuir model, which ranged from 0.97 to 0.99. The adsorption of lead ions by these organoclays was investigated using different sorption models including the Langmuir, Freundlich, and BET. It was found that, according to the values of limiting adsorption to the Langmuir equation, the synthesized organoclays formed an increasing series: organoclay with cocamide diethanolamine < bentonite < organoclay with lauramine oxide < organoclay with sodium cocoiminodipropionate < organoclay with disodium cocoamphodiacetate < organoclay with alkyl polyglucoside. The Gibbs energy for all of the analyzed samples was calculated and found to be negative, indicating the spontaneity of the cation adsorption process in the forward direction. The maximum value of the adsorption capacity of lead cations on organoclay-based bentonite with alkyl polyglucoside was 1.49 ± 0.05 mmol/g according to the Langmuir model, and 0.523 ± 0.003 mmol/g as determined by the BET model. In the process of modifying bentonite, there was an increase in negative values of the zeta potential for organoclays compared to the initial mineral, which clearly enhanced their electrostatic interactions with the positively charged lead ions. It was hypothesized, based on the physicochemical principles, that exchange adsorption is the main mechanism for lead absorption. Based on chemical approaches, organoclays based on amphoteric surfactants absorb lead mainly through the mechanisms of electrostatic attraction, ion exchange, and complexation as well as the formation of insoluble precipitates. Organoclays based on nonionic surfactants, on the other hand, absorb lead through mechanisms of complexation (including chelation) and the formation of insoluble chemical precipitates. The comparison of isotherms from different models allows us to find the most accurate match between the model and the experimental data, and to better understand the nature of the processes involved. Full article

In this review, we summarize the latest advances in the design of optical frequency-domain reflectometers (OFDRs), digital signal processing, and sensors based on special optical fibers. We discuss state-of-the-art approaches to improving metrological characteristics, such as spatial resolution, SNR, dynamic range, and the accuracy of determining back reflection coefficients. We also analyze the latest achievements in the OFDR-based sensors: the accuracy of spatial localization of the impact, the error in detecting temperatures, deformation, and other quantities, and the features of separate measurement of various physical quantities. We also pay attention to the trend of mutual integration of frequency-domain optical reflectometry methods with time-domain optical reflectometry, which provides completely new sensing possibilities. We believe that this review may be useful to engineers and scientists focused on developing a lab setup, complete measurement instrument, or sensing system with specific requirements. Full article

The present study investigates the photocatalytic properties of hydrothermally synthesized TiO₂ nanowires (NWs) for CO₂ reduction in H₂O vapor. It has been demonstrated that TiO₂ NWs, thermally treated at 500–700 °C, demonstrate an almost tenfold higher yield of products compared to the known commercial powder TiO₂ P25. It has been found that the best material is a combination of anatase, TiO₂-B and rutile. The product yield increases with increasing heat treatment temperature of TiO₂ NWs. This is associated with an increase in the degree of crystallinity of the material. It is shown that the best product yield of the CO₂ reduction in H₂O vapor is achieved when the TiO₂ NW photocatalyst is heated to 100 °C. Full article