Detection Of Low Levels Research Articles

A Copper-Selective Sensor and Its Inhibition of Copper-Amyloid Beta Aggregation

Copper is an essential trace metal for biological processes in humans and animals. A low level of copper detection at physiological pH using fluorescent probes is very important for in vitro applications, such as the detection of copper in water or urine, and in vivo applications, such as tracking the dynamic copper concentrations inside cells. Copper homeostasis is disrupted in neurological diseases like Alzheimer’s disease, and copper forms aggregates with amyloid beta (Ab42) peptide, resulting in senile plaques in Alzheimer’s brains. Therefore, a selective copper detector probe that can detect amyloid beta peptide-copper aggregates and decrease the aggregate size has potential uses in medicine. We have developed a series of Cu2+-selective low fluorescent to high fluorescent tri and tetradentate dentate ligands and conjugated them with a peptide ligand to amyloid-beta binding peptide to increase the solubility of the compounds and make the resultant compounds bind to Cu2+–amyloid aggregates. The copper selective compounds were developed using chemical scaffolds known to have high affinity and selectivity for Cu2+, and their conjugates with peptides were tested for affinity and selectivity towards Cu2+. The test results were used to inform further improvement of the next compound. The final Cu2+ chelator–peptide conjugate we developed showed high selectivity for Cu2+ and high fluorescence properties. The compound bound 1:1 to Cu2+ ion, as determined from its Job’s plot. Fluorescence of the ligand could be detected at nanomolar concentrations. The effect of this ligand on controlling Cu2+–Ab42 aggregation was studied using fluorescence assays and microscopy. It was found that the Cu2+–chelator–peptide conjugate efficiently reduced aggregate size and, therefore, acted as an inhibitor of Ab42-Cu2+ aggregation. Since high micromolar concentrations of Cu2+ are present in senile plaques, and Cu2+ accelerates the formation of toxic soluble aggregates of Ab42, which are precursors of insoluble plaques, the developed hybrid molecule can potentially serve as a therapeutic for Alzheimer’s disease.

Behavior of Thiamethoxam and Clothianidin in Young Oilseed Rape Plants before Flowering, Monitored by QuEChERS/LC–MS/MS Protocol

Behavior of Thiamethoxam and Clothianidin in Young Oilseed Rape Plants before Flowering, Monitored by QuEChERS/LC–MS/MS Protocol

Sustainable synthesis of praseodymium tungstate: An electrochemical probe for detection of Ronidazole

Profligate consumption of antibiotics in animal and livestock husbandry indulged in antibiotic pollution. This collapses the natural balance of the ecosystem and results in various environmental health crises. Herein, we have developed an ultra-sensitive praseodymium tungstate (PWO) based electrochemical sensor to detect one such serious antibiotic, Ronidazole (RD). A facile synthesis strategy was applied to prepare PWO nanomaterial and their structural, functional, and elemental details were thoroughly examined with a wide range of spectroscopic measurements. The electrochemical properties were determined by performing impedance and voltammetry experiments. The high catalytic efficiency of the designed sensor was achieved by optimizing its performance under different parameters. Based on the outcomes, the designed PWO-based sensor offered an extremely low level of detection (0.3 nM) and exhibited a wide range of linearity (0.001 µM to 20.4 µM), high sensitivity (7.72 µA µM−1 cm−2), and good selectivity. Further, the performance of the electrochemical sensor was validated with good repeatability, reproducibility, and stability results. The practical applicability of the sensor was investigated by monitoring the RD in aquatic, biological, and pharmaceutical samples. The obtained results affirmed that the PWO sensor is an efficient platform for the real-time monitoring of RD.

Study of conduction mechanism in swift heavy ion irradiated reduced graphene oxide samples and its applications towards low level detection of SO2 at room temperature

The reduced graphene oxide (rGO) sample is synthesized by the reduction of hydrazine hydrate. The prepared samples further reduced with swift heavy ion irradiation beam of silver (Ag8+) ions of 100 MeV energies. Ion beam irradiation causes defect in the rGO samples which is explained on the basis of Raman study. The removal of oxygen functional groups are explained on the basis of FTIR study. Ion irradiation has increased dc electrical conductivity on reduction. The room temperature dc conductivity of sample S4 is increases from 2.5 × 10−2 to 1.94 S/cm during reduction. The conduction mechanism is accounted by Mott's formulation of 3D variable range hopping model in the temperature range of 77 to 400 K. Along with it, the prepared samples are also tested for gas sensing abilities towards SO2 gas at 5 ppm. The sample exhibits good sensing properties towards analytes at room temperature.

In situ edge extraction enabled by reconfigurable van der Waals infrared photodetectors

At present, the widely used artificial intelligence image perception technology is composed of discrete detection and processing components, which is mismatching the demand for increasingly sizeable redundant image information processing. The transmission of non-critical information between components limits the efficiency of image perception systems. Inspired by the human vision system, which can extract the key features and reduce the transmission burden at the low-level detection end, we propose a symmetric structured mixed-dimensional n/p/n [n-molybdenum disulfide (MoS2)/p-germanium (Ge)/n-MoS2] interdigital van der Waals heterojunction infrared photodetector that can be tuned by bias voltage in response polarity and magnitude. The MoS2/Ge/MoS2 infrared photodetector has a bias-symmetric optoelectronic response and covers the detection band from visible to short-wave infrared. Through the joint detection of a pair of MoS2/Ge/MoS2 infrared photodetectors, we demonstrate the image in situ edge extraction at the detection end, which provides key features for high-level processing. This work has discovered the potential of retina-inspired infrared photodetectors on a 2D/3D integration platform, providing distinct opportunities for a neuromorphic visual perception hardware.

Advanced review of the contributing factors for the Microwave Digestion of food matrices for trace elemental analysis

Microwaves are electromagnetic waves which move at the speed of light. Samples directly exposed to this phenomenon are heated faster than conventional conduction heating methods. This is exploited in acid assisted digestion where a food sample in a suitable acid matrix can be completely destroyed leaving a clear solution of measurable elements. In pressurised systems the temperature can be rapidly increased far above the conventional boiling point of the solvent and the closed microwave vessel environment is ideal for volatile elements.There is a constant aspiration to achieve lower levels of detection and advances in instrument capabilities with specialised plasma based techniques for the identification and quantification of individual elements at ultra-trace levels have evolved. To realise this; sample preparation, digestion efficiency and sample introduction need to be optimised. Exogenous inputs such as preparation environment, reagent grade, the analyst and apparatus cleaning steps all have the potential to leave an elemental footprint on the sample and therefore contribute to the uncertainty of the analytical result. Knowledge of sample composition and subsequent interaction with microwaves and plasma are an important consideration for complete digestion without which the result is not accurate.

Актуальные проблемы эпидемиологии офтальмологической заболеваемости среди молодежи России и Центрального федерального округа.

Indicators of primary morbidity of the eyes and their appendages in adolescents aged 15–17 years and young people, in particular among students of higher educational institutions, increase annually due to increased visual stress as risk factors. The purpose of the work is to identify current problems in the epidemiology of ophthalmological morbidity among young people in the Russian Federation and the Central Federal District. Materials and methods. A theoretical analysis of the literature on the epidemiology of ophthalmic diseases in young people and a search for statistical data on the epidemiology of ophthalmic diseases was carried out. To assess the dynamics of epidemiological indicators, an increase calculation was carried out. Results. The increase in the incidence of visual organs in adolescents per 100 thousand children aged 15–17 years from 2000 to 2021 was +47.9%, and from 2018 to 2019 the increase in the incidence of myopia was +9.2%. In the structure of diseases for adolescents, it is pathologies of the visual organs that lead, and 40% of students have visual impairments, the detection of which increases by 3–7% annually, while the severity of myopia grows every year by 5–7%. The increase in morbidity of the eyes and adnexa in the Central Federal District for 2019–2021 was +57.5%, however, morbidity statistics do not consider the age distribution of diseases and their structure. The largest (+296.0 +110.1%) increase per 100 thousand population is observed for the Vladimir, Voronezh, Lipetsk, Ivanovo and Kaluga regions. It was revealed that in 2017, the incidence rate of eyes and their appendages in the Voronezh region over 10 years increased from 64.8 to 94.8 per 1000 students, 45.6% of students had impaired visual acuity. In the region, there is a staff shortage of ophthalmologists, insufficient coverage of preventive examinations and a low level of detection of patients at an early stage of disease. Conclusion. The epidemiology of eye diseases on the territory of the Russian Federation and its constituent entities in the young population has not been sufficiently studied. Improving regional analysis tools will help identify factors of variability in the epidemiology of eye diseases across the country’s regions. In regions with a high increase in ophthalmic morbidity, it is necessary to study in more detail the epidemiology of vision diseases in young people.

Gravity's impact on visual search asymmetries: Is visual gravitational motion a distinct visual feature or a familiar dynamic event?

A wealth of converging research lines has led support to the notion that specialized neural processes output a priori information about the expected effects of gravity to fine-tune motor and perceptual responses to dynamic events. Arguably, these putative internal models of gravity might modulate the efficiency in visual search for objects conforming or not to gravitationally coherent dynamics. In the present work, we explored this possibility with a visual search task involving arrays of two to eight objects moving periodically back and forth. The target could be an accelerating/decelerating ball (as if bouncing on earth's surface-1g) with distractors moving at a constant speed (0g) or the reverse. Moreover, the direction of the gravitational pull, as implied by the 1g motion patterns, could be aligned or misaligned with Earth's gravity. Overall, searches for 1g targets were more efficient than 0g targets except, notably, when stimuli displays were congruent with Earth's gravitational pull, in which case the visual search asymmetry is significantly reduced. Outcomes are interpreted as reflecting the joint and mutually cancelling contribution of low-level detection of acceleration patterns and higher level detection of unexpected violations of gravitational motion. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Multisignal Biosensors Based on Mn Paramagnetic Relaxation and Nanocatalysis for Norovirus Detection.

A multisignal method for the sensitive detection of norovirus based on Mn paramagnetic relaxation and nanocatalysis was developed. This dual-modality sensing platform was based on the strong relaxation generated by cracked Au@MnO2 nanoparticles (NPs) and their intrinsic enzyme-like activity. Ascorbic acid rapidly cracked the MnO2 layer of Au@MnO2 NPs to release Mn(II), resulting in the relaxation modality being in a "switch-on" state. Under the optimal conditions, the relaxation modality exhibited a wide working range (6.02 × 103-3.01 × 107 copies/μL) and a limit of detection (LOD) of 2.29 × 103 copies/μL. Using 4,4',4″,4″'-(porphine-5,10,15,20-tetrayl) tetrakis (benzenesulfonic acid) (tpps)-β-cyclodextrin (tpps-β-CD) as a T1 relaxation signal amplification reagent, a lower LOD was obtained. The colorimetric modality exploited the "peroxidase/oxidase-like" activity of Au@MnO2 NPs, which catalyzed the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxidized TMB, which exhibited a working range (6.02 × 104-6.02 × 106 copies/μL) and an LOD of 2.6 × 104 copies/μL. In addition, the rapid amplification reaction of recombinase polymerase enabled the detection of low norovirus levels in food samples and obtained a working range of 101-106 copies/mL and LOD of 101 copies/mL (relaxation modality). The accuracy of the sensor in the analysis of spiked samples was consistent with that of the real-time quantitative reverse transcription polymerase chain reaction, demonstrating the high accuracy and practical utility of the sensor.

Sustainable golden nanoflowers grafted food-waste derived biotemplate for the direct SERS-detection of carcinogenic herbicides from agro-farms

Surface Enhanced Raman Scattering (SERS) is emerging as a potent analytical tool for the detection of various pollutants in complex environments due to its distinctive vibrational fingerprint ability and pronounced detection sensitivity. Precautious of adverse blue-green economies and ecological impacts, sustainable generation of SERS active substrates and analyte casting matrices are getting prioritized. Herein, gold nanoflowers (AuNFs) of ∼75 ± 15 nm were initially biofabricated using an expended cell culture medium as a one-step synthesis cum stabilization strategy. Then the heavy architecture of multi-faceted AuNFs with deep pits and edges, that acted as hotspots for enhancing the localized electromagnetic fields, was utilized for the direct SERS detection of commonly used carcinogenic herbicides collected from agro-farms at nanomolar regimes with 0.44 ppm and 0.27 ppm for Glyphosate and amino methyl phosphonic acid, respectively. Such a low level detection is superior by 8.33% when compared to the reported values. Computational finite-difference time-domain (FDTD) simulations affirmed the enhanced SERS effect from the multi-faceted nanostructure of AuNFs with structural heterogeneities that provide numerous hotspots to amplify the localized electromagnetic field. More eminently, fish scale derived biotemplate through AuNF-analyte drop casting contributed to the exceptional intensities, attributed to the naturally grooved hierarchically porous hydrophilic lamellar structures contact angle of 73°. Overall, the adapted bioengineering of SERS substrate is safe, robust, affordable and reproducible, fostered by bioderived durable biomatrix offering potent sustainable SERS detection of various biomedically and environmentally relevant molecules.

Ultrathin Langmuir-Blodgett film of functionalized single-walled carbon nanotubes for enhanced acetone sensing

Acetone is one of the important volatile organic compounds which needs to be detected from the industrial effluent and as a bio-marker from breath of diabetic patients. Here, ultrathin Langmuir-Blodgett (LB) film of octadecylamine- functionalized single-walled carbon nanotubes (ODA-CNT) was formed on interdigitated gold electrodes and was employed for acetone vapor sensing using the impedance spectroscopy (IS) at room temperature. The LB film deposited in liquid-like phase of the Langmuir monolayer of ODA-CNT revealed aligned nanotubes. Being a reducing agent, acetone interacts readily with the CNTs through the transfer of electrons. Using IS, multiparameter were measured with respect to both frequency and acetone vapor concentration. Principal component analysis (PCA) of the IS data revealed capacitance as the most suitable parameter for acetone vapor sensing using the ODA-CNT film. A very low limit of detection (0.5 ppm) and a wide detectable concentration range (1–300 ppm) for acetone sensing using the LB film of ODA-CNT was obtained. The 2D calibration map revealed that the sensing performance of acetone using LB film was much better as compared to that of drop-cast film of ODA-CNT and LB film of pristine CNTs. The superior sensing performance of the LB film of ODA-CNT is attributed to the uniform and aligned nature of the nanotubes, leading to a coherent behavior due to interaction with the acetone molecules. This study shows the potential of LB films of ODA-CNT for sensitive and low level detection of acetone vapor at room temperature.

Novel variants ensued genomic imprinting in familial central precocious puberty

IntroductionCentral precocious puberty (CPP) is characterized by the early onset of puberty and is associated with the critical processes involved in the pubertal switch. The puberty-related gene pool in the human genome is considerably large though few have been described in CPP. Within those genes, the genomic imprinting features of the MKRN3 and DLK1 genes add additional complexity to the understanding of the pathologic pathways. This study aimed to investigate the molecular etiology in the CPP cohort.MethodsEighteen familial CPP cases were investigated by Sanger sequencing for five CPP-related genes; DLK1, KISS1, KISS1R, MKRN3, and PROKR2. Segregation analysis was performed in all patients with pathogenic variants. Using an ELISA test, the functional pathogenicity of novel variants was also investigated in conjunction with serum delta-like 1 homolog (DLK1) concentrations.ResultsIn three probands, a known variant in the MKRN3 gene (c.982C>T/p.(Arg328Cys)) and two novel variants in the DLK1 gene (c.357C>G/p.(Tyr119Ter) and c.67+78C>T) were identified. All three were inherited from the paternal allele. The individuals carrying the DLK1 variants had low detectable DLK1 levels in their serum.ConclusionsThe frequencies were 5.5% (1/18) for MKRN3 11% (2/18) for DLK1, and none for either KISS1, KISS1R, and PROKR2. Low serum DLK1 levels in affected individuals supported the relationship between here described novel DLK1 gene variants with CPP. Nonsense nature of c.357C>G/p.(Tyr119Ter) and an alteration in the evolutionarily conserved nucleotide c.67+78C>T suggested the disruptive nature of the variant's compatibility with CPP.

Core-Shell Nanocables Decorated with Carbon Spherical Shells and Silver Nanoparticles for Sensing Ethinylestradiol Hormone in Water Sources and Pills.

The selective, rapid detection of low levels of hormones in drinking water and foodstuffs requires materials suitable for inexpensive sensing platforms. We report on core-shell Ag@C nanocables (NCs) decorated with carbon spherical shells (CSSs) and silver nanoparticles (AgNPs) by using a hydrothermal green approach. Sensors were fabricated with homogeneous, porous films on screen-printed electrodes, which comprised a 115 nm silver core covered by a 122 nm thick carbon layer and CSSs with 168 nm in diameter. NCs and CSSs were also decorated with 10-25 nm AgNPs. The NC/CSS/AgNP sensor was used to detect ethinylestradiol using square wave voltammetry in 0.1 M phosphate buffer (pH 7.0) over the 1.0-10.0 μM linear range with a detection limit of 0.76 μM. The sensor was then applied to detect ethinylestradiol in tap water samples and a contraceptive pill with recovery percentages between 93 and 101%. The high performance in terms of sensitivity and selectivity for hormones is attributed to the synergy between the carbon nanomaterials and AgNPs, which not only increased the sensor surface area and provided sites for electron exchange but also imparted an increased surface area.

Tyramine-Invertase Bioconjugate-Amplified Personal Glucose Meter Signaling for Ultrasensitive Immunoassay.

Highly sensitive and facile detection of low levels of protein markers is of great significance for the early diagnosis and efficacy monitoring of diseases. Herein, aided by an efficient tyramine-signal amplification (TSA) mechanism, we wish to report a simple but ultrasensitive immunoassay with signal readout on a portable personal glucose meter (PGM). In this study, the bioconjugates of tyramine and invertase (Tyr-inv), which act as the critical bridge to convert and amplify the protein concentration information into glucose, are prepared following a click chemistry reaction. Then, in the presence of a target protein, the sandwich immunoreaction between the immobilized capture antibody, the target protein, and the horseradish peroxidase (HRP)-conjugated detection antibody is specifically performed in a 96-well microplate. Subsequently, the specifically loaded HRP-conjugated detection antibodies will catalyze the amplified deposition of a large number of Tyr-inv molecules onto adjacent proteins through highly efficient TSA. Then, the deposited invertase, whose dosage can faithfully reflect the original concentration of the target protein, can efficiently convert sucrose to glucose. The amount of finally produced glucose is simply quantified by the PGM, realizing the highly sensitive detection of trace protein markers such as the carcinoembryonic antigen and alpha fetoprotein antigen at the fg/mL level. This method is simple, cost-effective, and ultrasensitive without the requirement of sophisticated instruments or specialized laboratory equipment, which may provide a universal and promising technology for highly sensitive immunoassay for in vitro diagnosis of diseases.

INTESTINAL PARASITES OF THE BROWN BEAR (URSUS ARCTOS LINNAEUS, 1758) IN THE EAST KAZAKHSTAN REGION

The article analyzes the literature data and own research on the distribution and species composition of helminths and eimeria in brown bears in the East Kazakhstan region. The aim of the study was to identify a type of helminth in American black bears (Ursus americanus). The relatively low level of parasite detection in this study is in line with expectations for populations of brown bears (Ursus arctos) living in large areas. Tasks: to identify and study the type of helminths in the brown bear. On the territory of the Russian Federation, the brown bear has 17 species of helminths (including 3 species of trematodes and 14 species of nematodes) and 2 species of protozoa. Most of the discovered species of helminths, eimeria, cryptosporidia both in zoos, circuses, and in the natural habitat of brown bears: European, Siberian and Far Eastern parts of Russia have epizootological and epidemiological significance. For the first time, we registered bears in the territory of the Republic of Kazakhstan.

Electrochemical control of the morphological evolution of PEDOT on a Ni-Co(OH)2/carbon cloth surface to modulate the performance of wearable H2O2 sensors.

The slow redox rate of hydrogen peroxide (H2O2) in neutral environments makes the H2O2 sensor inadequate for the detection of low levels of signalling molecules. The aim of this study is to fabricate a flexible sensing electrode by hydrothermally loading micro-nanometer Ni and Co(OH)2 on carbon cloth (CC) and electrochemically depositing poly(3,4-ethylenedioxythiophene) (PEDOT) on the surface of the electrode. The sensor presented high sensitivity (10.43 mA mM-1 cm-2), a wide detection range (0.033-120.848 mM), a low detection limit (0.92 nM), high stability, and excellent anti-interference performance in neutral solutions. Ni-Co(OH)2 provides abundant active sites while CC solves their agglomeration phenomenon and conductivity. The PEDOT film offers heightened conductivity, hydrophilicity, interfacial stability, and an electrochemically active surface area (ECSA). The side area of the chrysanthemum petal like PEDOT is 39 ± 7 times the bottom area, and PEDOT increases the ECSA of the composite to six times that of CC. Electrochemical precise control of PEDOT morphology to improve sensor performance provides a new strategy for the application of PEDOT in sensors.

Kisspeptin levels in polycystic ovary syndrome and its manifestations

Background: The altered luteinizing hormone to follicle-stimulating hormone (LH/FSH) ratio- an important component in the pathogenesis of polycystic ovary syndrome (PCOS), is regulated by a brain peptide kisspeptin. This study aimed to explore the association of serum kisspeptin levels with PCOS and its manifestations. Methods: This cross-sectional study included 80 participants with PCOS on the basis of International evidence-based guidelines, 2018, and 71 healthy matched controls. Along with clinical information, fasting blood was drawn to measure total testosterone, sex hormone binding globulin, thyroid stimulating hormone, prolactin, 17-hydroxyprogesterone, and kisspeptin in all, and glucose, lipids, insulin, LH, FSH in only PCOS participants in the follicular phase of the menstrual cycle. Kisspeptin was measured by sandwiched enzyme-linked immunosorbent assay method with a lower limit detection level of 0.01 pg/mL. Result: Kisspeptin levels were undetectable in 25 out of 80 and 16 out of 71 controls. Among the participants with detection levels (55 in each group), kisspeptin did not differ between PCOS and control [31.2 (19.2 – 43.1) vs. 40.4 (14.9 – 70.4), pg/mL, p=0.446]. Among participants with PCOS, kisspeptin levels had no significant associations or correlations with any manifestations (ns for all). ROC curve analysis showed kisspeptin as not an acceptable marker for PCOS [AUC (95% CI): 0.57 (0.46 – 0.68), p= 0.221]. Conclusion: Our study failed to show any association of kisspeptin levels with PCOS and its manifestations.

Ni-Pt nanozyme-mediated relaxation and colorimetric sensor for dual-modality detection of norovirus

An NiPt nanozyme-mediated relaxation and colorimetric sensor is developed for dual-modality detection of norovirus (NoV). The relaxation modality is based on the “catalase-like” activity of the NiPt nanozyme, which adjusts the hydrogen peroxide (H2O2) mediated Fe (II)/Fe(III) conversion, thereby changing the relaxation signal. Poly-γ-glutamic acid (MW ≈ 1w) can enhance the relaxivity of Fe(III) (r1 = 7.11 mM−1 s−1; r2 = 8.94 mM−1 s−1). The colorimetric modality exploits the “peroxidase-like” activity of the NiPt nanozyme, which can catalyze the oxidation of colorless 3, 3′, 5, 5′-tetramethylbenzidine (TMB) to blue oxTMB in H2O2. Under optimal conditions, the relaxation modality exhibits a wide working range (1.0 × 101–1.0 × 104 fM) and a limit of detection (LOD) of 4.7 fM (equivalent to 2820 copies/μL). The spiked recoveries range from 99.593 to 106.442 %, and the relative standard deviation (RSD) is less than 5.124 %. The colorimetric modality exhibited the same working range with a lower LOD of 2.9 fM (equivalent to 1740 copies/μL) and an RSD of less than 2.611 %. Additionally, the recombinase polymerase amplification reaction enabled the detection of low NoV levels in food samples with a working range of 102–106 copies/mL and LOD of 102 copies/mL. The accuracy of the sensor in the analysis of spiked samples is consistent with the gold standard method (real-time quantitative reverse transcription-polymerase chain reaction), demonstrating the high accuracy and practical utility of the sensor.

FEATURES OF CYTOKINE PRODUCTION DURING REHABILITATION AFTER COVID-19 IN PEOPLE LIVING IN THE NORTHERN REGIONS OF SIBERIA

The coronavirus infection of 2019 (COVID-19) has significantly affected the modern world. Recently, it has been proven that IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF-α play an important role in the inflammatory response of the body to SARS-CoV-2 infection.
 Purpose. To study the features of the synthesis of key cytokines in residents of the Turukhansky district of the Krasnoyarsk Territory who underwent COVID-19.
 Materials and methods. On the basis of "Turukhanskaya RB", village. Turukhansk, in February 2023, 98 patients were examined, the average age was 58 (± 5 years). Of the 98 participants interviewed, 76 people had an official diagnosis of COVID-19 in the period from October 2020. The study was conducted with the permission of the ethical committee of the Research Institute of Medical Problems of the North. Each participant signed an informed consent form for the examination, according to the Helsinki Declaration of the World Medical Association regulating the conduct of scientific research.
 Results. A high IgG titer to SARS-Cov-2 was observed in 99% of the examined, a positive IdM titer to SARS-Cov-2 was in 1% of the examined. In the course of studying the features of the cytokine network in patients with Turukhansk there was a significant decrease in the concentration of α-TNF, IL-1b and IL-10, as well as an increase in IL-2, IL-6 and IL-8 relative to the control group of Krasnoyarsk. α-IFN and IL-4 showed no significant changes and remained within the control range. At the same time, no differences were found between the groups of patients with a confirmed diagnosis of COVID-19 and without it.
 Conclusion. The data obtained indicate a high level of homogeneity of the sample in the village . Turukhansk, regardless of the presence of the disease, about the low level of detection and control over the course of COVID-19. We observe the formation of a chronic inflammatory process against the background of the prevalence of pro-inflammatory function and an increase in the concentration of pro-inflammatory cytokines, which can subsequently deplete the body's resources and contribute to the development of additional complications.

Development of Liquid-Phase Plasmonic Sensor Platforms for Prospective Biomedical Applications.

Localized Surface Plasmon Resonance (LSPR) is an optical method for detecting changes in refractive index by the interaction between incident light and delocalized electrons within specific metal thin films' localized "hot spots". LSPR-based sensors possess advantages, including their compact size, enhanced sensitivity, cost-effectiveness, and suitability for point-of-care applications. This research focuses on the development of LSPR-based nanohole arrays (NHAs) as a platform for monitoring probe/target binding events in real time without labeling, for low-level biomolecular target detection in biomedical diagnostics. To achieve this objective, this study involves creating a liquid-phase setup for capturing target molecules. Finite-difference time-domain simulations revealed that a 75 nm thickness of gold (Au) is ideal for NHA structures, which were visually examined using scanning electron microscopy. To illustrate the functionality of the liquid-phase sensor, a PDMS microfluidic channel was fabricated using a 3D-printed mold with a glass slide base and a top glass cover slip, enabling reflectance-mode measurements from each of four device sectors. This study shows the design, fabrication, and assessment of NHA-based LSPR sensor platforms within a PDMS microfluidic channel, confirming the sensor's functionality and reproducibility in a liquid-phase environment.