Analysis Method Research Articles

Microplastics in Urban Ambient Air: A Rapid Review of Active Sampling and Analytical Methods for Human Risk Assessment

This study conducted a rapid review to evaluate active air sampling and analytical methods for characterizing outdoor air microplastics in urban areas. We synthesized information from 35 peer-reviewed journal articles. Studies utilizing active sampling methods were able to provide detailed data on inhalation concentrations and doses. The analytical techniques reviewed were categorized into microscopy, Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and mass spectrometry, including pyrolysis–gas chromatography (Py-GC). While conventional FTIR and Raman spectroscopy can identify microplastics in total suspended particles, advanced instruments such as µRaman and SEM are crucial for analyzing inhalable microplastics (e.g., particles smaller than 10 µm). Characterizing the shapes and colours of microplastics can provide qualitative estimates of their sources, with fibres and the colour black being the most predominant characteristics. Establishing dose–response relationships for health effects requires quantitative analyses; thus, combining techniques like µRaman with Py-GC is essential for comprehensive human risk assessments. Future studies should focus on identifying and quantifying inhalable microplastic compounds that are relevant to human health.

Nutrients and Antioxidant Composition of Local Condiment “Ogiri” Produced from Different Leguminous Seeds

‘Ogiri’ refers to a fermented oily paste that is used as soup condiments for its strong smell. Apart from the fact that it’s mostly used in soup preparation because of the strong pungent odour and organoleptic properties, it also impact nutrients to soup. This study investigated the nutrients and antioxidant composition of Ogiri produced from different leguminous seeds. Raw material such as melon (EGU) and sesame (SES) seeds were procured from Oja Oba (Oba Market) in Owo, Ondo State while pumpkin (PUM) and Castor (CAS) seed were purchased at Upper Iweka market, Onitsha Anambra State, Nigeria. The raw materials were processed into ‘Ogiri’ using traditional methods and were subjected to chemical analysis using standard analytical methods.” Data generated were subjected to One-way Analysis of Variance (ANOVA) and means were separated using Duncan Multiple Range Test at 5% level of significance. Findings shows that the moisture content was significantly (P<0.05) higher in PUM than any other sample. Sample SES was significantly (P<0.05) higher in Ash (10.22g /100g) content, and fibre (11.21g/100g) while EGU was significantly (P<0.05) higher in fat (30.17g/100g) and protein (29.30g/100g). CAS had the highest carbohydrate content (27.58g/100g).Minerals result shows that Na (14.835mg/g), Ca (22.570mg/100g) and Mg (3.351mg/100g) were significantly (P<0.05) higher in sample EGU. Sample SES was significantly higher in K (55.855mg/100g) and Zn (0.308mg/100g), while CAS was significantly lower (P<0.05) in Na (3.45mg/100g), Ca (13.15mg/100g) K, (21.655mg/100g), Zn (0.128mg/100g) and Mg (1.925mg/mg) but has the highest value in P (12,252mg/100g). PUM was significantly higher in Vitamin E (8.270mg/100g), while CAS was significantly higher in vitamin A (7.576UI/g). Sample PUM had the highest Polyphenol and Terpenoid content (106.82mg/g and 1.37mg/g respectively) while sample SES had the highest steroid content (0.92mg/g). In conclusion, this study revealed that the nutrients and antioxidant properties of the “Ogiri” samples vary proportionately. The results can guide farmers, processors, and consumers in making informed decisions regarding seed selection and Ogiri preparation.

Characterization of poly(A) and poly(T) tail lengths in plasmid DNA by liquid chromatography high-resolution mass spectrometry.

Rapid advances in messenger RNA (mRNA) technology necessitate effective analytical methods. This study describes the development of a novel in vitro method using ion-pair reversed-phase liquid chromatography coupled to high-resolution mass spectrometry (IP-RP-LC-HRMS) for assessing the poly(A) and complementary poly(T) tail lengths directly into the DNA template used to manufacture mRNA. Briefly, after the validation of poly(A) tail length in the plasmid by Sanger sequencing, double-stranded DNA fragments containing these tails in the plasmid of interest were amplified by thepolymerase chain reaction (PCR), purified on silica column, and digested with restriction enzymes ClaI and HindIII. Gel or capillary electrophoresis confirmed sample quality and enzymatic digestion efficiency. Subsequently, poly(A) and complementary poly(T) tails were extracted and analyzed by LC-MS to determine their length and heterogeneity at a single-nucleotide resolution. Three DNA templates containing poly(A) tail lengths of 60A-G, 95A, or 108A were studied. LC-MS results correlated well with Sanger sequencing, identifying major populations of 60A-G, 95A, or 108A. Surprisingly, unlike Sanger sequencing, LC-MS analysis revealed minor poly(A) populations with lengths longer or shorter than the theoretically encoded poly(A) tail length. This finding could be explained by (i) the slippage of bacterial DNA polymerase I during plasmid replication in bacterial culture, which occurs on repeat mononucleotide sequences, or (ii) the slippage of Q5® High-Fidelity DNA Polymerase during PCR amplification. In conclusion, the method is easy, rapid, and accurate and could replace Sanger sequencing to assess the poly(A) and complementary poly(T) tail lengths in plasmid DNA.

An orthogonal approach for analysis of underivatized steroid hormones using ultrahigh performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS).

The crucial role of steroid hormones in health and diseases merits their high-throughput, accurate and affordable measurements in biological specimens. Despite advances in analytical methods, sensing and quantifying steroid hormones remains challenging. Immunoassays offer excellent sensitivity but are inherently labour-intensive, costly, and prone to false positives. Mass spectrometry (MS) has been increasingly utilised, with the main hurdle being the isobaric tendencies of similar analytes, which complicates their separation and accurate quantification. This study compares ultrahigh-performance supercritical fluid chromatography separation (UHPSFC) and ultra-high-performance liquid chromatography (UHPLC) for MS detection. It optimises the column chemistry, temperature, and pressure to provide an operational protocol for the resolution and quantification of analytes. It presents the systematic characterisation of UHPSFC-MS performance by investigating spiked blood samples using Solid-Phase Extraction (SPE) and describes the matrix effects associated with MS measurements. Although both separation methods showed adequate resolution, specificity, and retention time, UHPSFC-MS was superior for five out of seven columns tested. With added high-throughput capacities, UHPSFC-MS, thus, offers an optimal solution for the analysis of steroid hormones for research, medical chemistry, and clinical diagnostics.

A Study of Dimensions of Islamophobia in Nigeria: Causes and Solutions

Islamophobia is an unfounded fear of Islam and, more accurately, of his adherents i.e. Muslims. This phenomenon has found a fertile terrain in Nigeria given her status as a multi-religious society where Muslims and Christians live together as citizens. Over the years, Islamophobia has taken constitutional, diplomatic, educational, financial, and political dimensions in the country. Any Attempt by Muslims to live in line with their religious codes of conduct and without violating the constitutional provisions is often misconstrued by Christians - their religious counterparts- as a systematic way of Islamizing the country. However, the imaginary fear of Islam/Muslims by Christians is belied by the realities on ground. Against this backdrop, this paper will cast a look at Islamophobia as a concept with a view to highlight its various dimensions in Nigeria. After identifying possible causes of Islamophobia, practicable solutions shall be proffered accordingly. To achieve the objective, both historical and analytical methods shall be employed. Available resources as well as events in the recent past reveal that Islamophobia is not unconnected with misinformation about Islam at the instance of some orientalists. It is also a possible consequence of violent activities of insurgent groups like Boko Haram which proclaim the Islamization agenda to terrorize the entire nation. The paper shall show that this insurgent group is ignorance based and stands condemned by the Muslim authority in the country. As such, the paper suggests adequate knowledge and tolerance as critical tools to curtail the menace of Islamophobia. This will go a long way in achieving mutual tolerance and peaceful co-existence among the adherents of Christianity, Islam, and other religions in Nigeria.

Tailoring of Novel Ru (III) and Cr (III) Salen Complexes as Catalysts for a Sustainable and Green Synthesis of Dihydro‐tetrazolo [1,5‐a] thiazolo [4,5‐d] pyrimidin‐6‐yl morpholine: Experimental and Theoretical Approaches

ABSTRACTTwo novel Cr (III) and Ru (III) salen complexes based on {3,4‐Bis‐[(5‐chloro‐2‐hydroxy‐benzylidene)‐amino]‐phenyl}‐phenyl‐methanone ligand (CSAB) were synthesized. The complexes were characterized using various spectral and analytical methods. The catalytic performance of the CSAB complexes was investigated via a four‐component condensation reaction involving aromatic aldehydes, rhodamine, morpholine, and 5‐aminotetrazole under mild, environmentally friendly conditions. Different Lewis acids, bases, ionic liquid catalysts, solvents, and catalyst amounts were assessed to optimize the reaction parameters. Both catalyst systems demonstrated robust catalytic activity under strictly managed conditions, with the heterogeneous catalyst CSAB‐Ru showing superior efficacy compared to the homogeneous CSAB‐Cr catalyst. The study confirmed the catalytic capabilities of both complexes and evaluated their recyclability and reusability. The heterogeneous catalyst (CSAB‐Ru) could be reused seven times, whereas the homogeneous catalyst (CSAB‐Cr) could be recycled four times. Both complexes demonstrated strong catalytic activity and selectivity, resulting in high product yields. The study provides insights into the synthetic applications of novel CSAB complexes, highlighting their potential in organic transformations. It emphasizes their ease of use, safety, stability, component availability, quick reaction times, and high yields, making them promising for future industrial applications.

Internal control of the commercial bank resource use efficiency

Subject. This article considers the methodological approaches to the analysis of banking resources from the point of view of their possible use in controlling the efficiency of resource provision and funding of commercial banks. Objectives. The article aims to test standard analytical methods used in the analysis of economic indicators characterizing the efficiency of banking activities in order to draw conclusions about the possibility of their application to control the risks of resource availability. Methods. For the study, we used induction and deduction, analysis and synthesis, modeling, comparison, extrapolation, abstraction, as well as financial analysis and analytical calculations of indicators developed by the banking regulator to identify risk areas and determine key economic and financial indicators of a commercial bank. Results. The article finds that banks are experiencing difficulties in achieving the appropriate efficiency of resource provision within the parameters set by the regulator, which indicates the need to control performance indicators, especially those characterizing resource provision, and their use as one of the main generators of profit from core activities. Conclusions and Relevance. In the context of crisis phenomena in the banking sector, it is necessary to pay attention to the control of ensuring the profitability of resources attracted by the bank, as well as the factors affecting it, the main of which are the return on assets and liabilities and the completeness of the allocation of financial resources. The results of studying the methods of economic analysis for assessing the efficiency of resource provision can be useful for studying the problems of using bank resources and assessing their efficiency, as well as monitoring of efficiency parameters for internal control purposes.

Accounting and analytical support of internal control of receivables at construction organizations

Subject. This article deals with the issues of improving the internal control of accounts receivable of economic entities of the construction industry. Objectives. The article aims to develop a detailed methodology for internal control of accounts receivable, including systematized procedures structured by control stage, based on the automation of accounting processes. Methods. For the study, we used the case, statistical, and analytical research methods, as well as special methodological techniques used in control and audit practice. Results. The article finds that with the ineffective activities of the internal control service, there is a delay in the receipt of funds from buyers, as a result of which the pace of construction and installation work slows down, and the probability of the risk of untimely commissioning of the facility increases. The article identifies the main reasons hindering the development of the construction industry, and offers the author-developed methodology for controlling settlements with counterparties, which provides for the step-by-step implementation of the formulated procedures based on the automation of accounting functions. Conclusions and Relevance. The introduction of escrow accounts and the transformation of accounting for settlements with participants in shared-equity construction are the main steps towards improving transparency and reliability in the field of shared-equity construction and necessitate the formation of an effective internal control system, taking into account the industry aspect, which makes it possible to minimize the risk of late repayment of receivables. The results of the study can be used by economic entities of the construction industry as a method of internal control of accounts receivable.

Adaptive algorithms for drone flight control under communication constraints and information incompleteness

Abstract With the rapid increase in the use of drones in various applications, including commercial and governmental, and the increasing probability of communication failures and contingencies, research becomes critical to ensure the safety and efficiency of their operations. The aim of this research is to develop adaptive drone flight control algorithms capable of operating effectively under conditions of limited communication and incomplete information to ensure reliable and safe autonomous operation of these systems. The applied methods include computer modelling and simulation, analytical, statistical, functional, deductive and descriptive methods. The study found that the use of performance evaluation methods for complex systems enables the identification of safety and performance criteria for drones, and drone flight control provides basic principles and methods that can be adapted for drones, including autopiloting and navigation. In addition, analyses of satellite communication and navigation prove the need to consider the limitations of this technology when developing drone control algorithms. The combination of these techniques allows for more robust and adaptive drone control systems that can function effectively in complex environments such as communication limitations and incomplete information. Additionally, it was found that the integration of adaptive control algorithms based on these methods allows drones to effectively adapt to variable environmental conditions and make decisions quickly even when communication is lost or information is limited.

HOW NOT TO DO EUROPEAN INTEGRATIONS: BOSNIA AND HERZEGOVINA AND LEGAL CHALLENGES IN ACCESSION PROCESS TO EUROPEAN UNION

Background: Bosnia and Herzegovina, with its complex constitutional and legal system, is facing many difficulties in its progress toward European Union membership. These challenges have been worsened by political instability, exacerbated by geopolitical shifts in Europe following Russian aggression on Ukraine. Legal complexities in the constitutional order of Bosnia and Herzegovina are often used to halt the country's progress and divert it from its European trajectory. This article analyses the specific instances of very unfavourable legal solutions that are hindering the EU accession process, as well as the recommendations put forth by the EU Commission aimed at removing these legal obstacles. There is an urgent need for reform of constitutional and legal rules to enable the country to effectively continue its EU accession path. The importance of the EU membership perspective for Bosnia and Herzegovina extends beyond simply joining a desirable club of prosperous countries; the reforms required during the EU accession process are needed to strengthen the efficiency of state institutions and secure lasting peace in the country and region. As such, the urgency and potential impact of these proposed legislative changes cannot be overstated. Methods: The research primarily employs a combination of analytical, normative, and comparative methods to examine the legal system and chronology of the integration process. The legal historical method is also used where appropriate. The research focuses on the content of constitutional norms, relevant legislative acts in Bosnia and Herzegovina, and legislative acts of the European Union and other countries. These legislative acts are compared with EU recommendations and legislation from other EU member states to identify the discrepancies. The article provides an overview of the legal framework governing EU integrations in Bosnia and Herzegovina, including norms of international law, constitutional law, national legislation, and EU law that are negatively impacting the EU accession process, and offers certain recommendations for their improvement. Results and conclusions: The research has identified certain norms of constitutional and legislative origin in the legal system of Bosnia and Herzegovina that are harming the country's ability to effectively engage in the EU accession process. Through a normative approach, the article gives recommendations for their improvement, which are in line with the standards set by the institutions of the EU. Amending these problematic legal frameworks would remove their use as political tools aimed at halting the country’s progress in the EU integrations.

Development and Validation of a Stability Indicating Analytical Method for the Estimation of Gliclazide and Sitagliptin in Bulk Drugs and Tablet Dosage Forms by RP-UPLC: An Application of the Quality-by-Design Approach

Sitagliptin and gliclazide are the active ingredients in OpdualagTM. A highly selective DPP-4 inhibitor, sitagliptin is thought to work in type 2 diabetics by delaying the inactivation of incretin hormones, which increases their concentration and lengthens their duration of effect. Sulfonyl urea mostly enhances insulin secretion from pancreatic β-cells by inhibiting ATP-sensitive K+ channels, leading to depolarisation and Ca2+ influx. Reduced serum glucagon levels and enhanced insulin binding to receptors and target tissues are the mechanisms by which it exerts its effects. Objective: This study aims to create and evaluate an RP-UPLC technique for the detection of sitagliptin and gliclazide in pharmaceutical products by applying AQbD principles. Method: Findings By utilising the Design-expert® programme, we were able to execute a central composite design (CCD) consisting of three components arranged in five distinct layers, which greatly improved the chromatographic conditions. One method that oversees the whole analytical procedure life cycle—from method design and optimisation to validation and continual improvement—is Analytical Quality by Design (AQbD). Results: The retention times for sitagliptin were 1.269 minutes and for gliclazide they were 1.572 minutes. The limits of detection (LOD) and quantitation (LOQ) for Sitagliptin and Gliclazide were 0.19 µg/mL, 0.56 µg/mL, 0.28 µg/mL, and 0.86 µg/mL respectively. The recovery percentages for sitagliptin and gliclazide were found to be 99.15% to 100.54% and 99.93% to 100.58%, respectively. Both drugs were found to be susceptible to oxidative and photolytic breakdown in the forced degradation studies. Conclusions A novel RP-UPLC method has been developed for the quantitative detection of sitagliptin and gliclazide in pharmaceutical formulations, utilising the AQbD-based methodology. This approach is straightforward, rapid, precise, particular, and stable-indicating.

Plant-Derived and Synthetic Nicotine in E-Cigarettes: Is Differentiation with NMR Spectroscopy Possible?

To circumvent regulatory frameworks, many producers start to substitute plant-derived nicotine (tobacco-derived nicotine, TDN) by synthetic nicotine (tobacco-free nicotine, TFN) in e-cigarette products. Due to the higher costs of enantiomeric synthesis and purification of TFN, there is a need to develop an analytical method that clearly distinguishes between the two sources. To trace nicotine's origin, its enantiomeric purity can be postulated by 1H NMR spectroscopy using (R)-(-)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BNPPA) as a chiral complexing agent. Low-field (LF) NMR conditions were optimized for this purpose even using a small amount of e-liquid sample (limit of quantification 8 mg/mL nicotine). All investigated products were found to contain one isomer (most likely (S)-(-)-nicotine). A direct 13C NMR method at natural abundance has been validated to differentiate (S)-TDN and (S)-TFN in e-cigarettes produced using nicotine of different origin. The method is based on calculation of the relative 13C content of 10 C-positions of the nicotine molecule with intraday and interday precisions below <0.2%. The method was applied to 12 commercial e-cigarette products labeled as containing TDN and TFN. Principal component analysis (PCA) was applied to the relative peak areas to visualize the difference between studied products. The LF 1H NMR method is a good alternative to expensive high-field NMR to differentiate between a racemate mixture and single optical isomers, whereas only high-precision 13C NMR can be used to distinguish (S)-TDN and (S)-TFN in e-cigarettes after appropriate sample extraction.

EXTRACTION, Extraction, Isolation, Identification and Estimation of Diosgenin by TLC Profiling and UHPLC-LC-SRM Analysis in Three Costus Species

Medicinal plants are utilized for treating many ailments, since ancient times due to their tremendous therapeutic properties. The plant derivatives are used as a raw material for the synthesis of drugs either as a natural or artificial synthetic drug. Costaceae family members are known to possess many medicinal properties few of them are mainly consumed to reduce the blood glucose level and treat many disorders. The sapogenin contained in the rhizome of three Costus species was extracted, identified, and characterized. Young rhizomes were harvested surface sterilized, hydrolyzed; extracted through a soxhlet apparatus and concentrated fractions were subjected to a preliminary phytochemical screening test for saponin, Thin Layer Chromatography, and the UHPLC-MS SRM analysis. The result showed that the maximum yield of the Diosgenin was obtained from the chloroform extract of Costus speciosus. The pharmaceutical analysis in all the three Costus species carried out with isolated saponin was compared with standard Diosgenin. The characterization of isolated diosgenin was done by UHPLC MS and SRM, based on the retention time of all three samples and the comparison with standard Diosgenin. Isolated Diosgenin was quantified through thin layer chromatography with n-hexane: ethyl acetate (7:3) as mobile phase at Rf value of 0.48. The amount of Isolated Diosgenin was estimated by comparing the peak area at a retention time Rt value of 8.5 in all the samples and compared with standard Diosgenin high amount of Diosgenin was found in Costus speciosus rhizome followed by Costus igneus and Costus pictus. The preliminary phytochemical screening and analytical methods involved during the present study were found satisfactory. Thus, the protocol can be used for the extraction of Diosgenin and further used in the synthesis of Drugs. Keywords: Costus pictus, Costus speciosus, Costus igneus, rhizome, TLC, UHPLC-MS, SRM

Enantiomer-Specific Stable Carbon and Nitrogen Isotopic Analyses of Underivatized Individual l- and d-Amino Acids by HPLC + HPLC Separation and Nano-EA/IRMS.

We developed a new method for stable carbon and nitrogen isotopic (δ13C and δ15N) analysis of underivatized amino acid (AA) enantiomers simultaneously, based on high-performance liquid chromatography (HPLC) separation and off-line isotopic measurement. l- and d-Enantiomers of each AA were isolated using a ReproSil Chiral-AA column, purified by wet chemical procedure, and analyzed for δ13C and δ15N values with a nanomol-scale elemental analyzer/isotope-ratio mass spectrometry (nano-EA/IRMS) system. We successfully achieved the separation of l- and d-enantiomers of 15 proteinogenous AAs, with all l-enantiomers eluting before respective d-enantiomers. The δ13C and δ15N values of AA enantiomers were consistent before and after HPLC separation, demonstrating that this analytical method conserves isotopic information. By coupling this column with a multidimensional HPLC system for isolating individual AAs, we analyzed l- and d-AAs in a natural sample, peptidoglycan isolated from Gram-positive bacterium Bacillus subtilis. Results show a surprisingly large 15N-depletion, up to 20‰, in d-glutamic acid relative to its l-counterpart. The first example, to our knowledge, of δ13C and δ15N analyses of underivatized AA enantiomers is expected to contribute to various research areas in the future.

Advances in genomics analysis for microbial soil remediation

Abstract. Soil pollution is a global environmental problem that poses a threat to ecological balance and human health. Microbial soil remediation is an eco-friendly technology that utilizes microorganisms to degrade or transform soil pollutants. Due to some drawbacks of traditional soil remediation methods, microbial remediation method has become a hot research topic nowadays. In recent years, the development of genomics analysis technology has greatly promoted the progress of microbial remediation research, and the use of genomics approach is free from the technical constraints of traditional research and can efficiently obtain the relative abundance of microbial communities and other information. In this paper, we reviewed the application of genomics in microbial soil remediation, and discussed the genomic analysis of several examples of heavy metal contaminated soil remediation, which provides a reference for researchers to quickly screen analytical methods in the field of microbial soil remediation, and reveals the biological significance of genomics analytical techniques.

Brain-wide alterations revealed by spatial transcriptomics and proteomics in COVID-19 infection.

Understanding the pathophysiology of neurological symptoms observed after severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is essential to optimizing outcomes and therapeutics. To date, small sample sizes and narrow molecular profiling have limited the generalizability of findings. In this study, we profiled multiple cortical and subcortical regions in postmortem brains of patients with coronavirus disease 2019 (COVID-19) and controls with matched pulmonary pathology (total n = 42) using spatial transcriptomics, bulk gene expression and proteomics. We observed a multi-regional antiviral response without direct active SARS-CoV2 infection. We identified dysregulation of mitochondrial and synaptic pathways in deep-layer excitatory neurons and upregulation of neuroinflammation in glia, consistent across both mRNA and protein. Remarkably, these alterations overlapped substantially with changes in age-related neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. Our work, combining multiple experimental and analytical methods, demonstrates the brain-wide impact of severe acute/subacute COVID-19, involving both cortical and subcortical regions, shedding light on potential therapeutic targets within pathways typically associated with pathological aging and neurodegeneration.

Reflection phenomena of thermoelastic plane waves on a rigid surface within a size-dependent elastic media

The current investigation aims to comprehend the spread of time-harmonic thermoelastic plane waves in an isotropic and homogeneous nonlocal elastic material without bounds, within the framework of the Lord–Shulman model and Eringen’s nonlocal stress model. Our analysis reveals two sets of coupled longitudinal waves and one independent shear-type wave. The coupled longitudinal waves experience dispersion and damping over time due to the dissipative nature of the L-S model. In contrast, the vertically shear-type waves exhibit dispersion characteristics due to the presence of nonlocality in the medium. Furthermore, we observe that the shear-type wave encounters a critical frequency, while the coupled longitudinal waves may face critical frequency conditions under certain circumstances. We explore the reflection of thermoelastic waves at a rigid, thermally insulated, and isothermal boundary of a thermoelastic half-space, particularly in the case of an incident coupled longitudinal thermoelastic wave. We determine the amplitude ratios of the reflected waves to the incident wave through analytical methods. For a specific model, we generate various graphs to analyze the behavior of phase speeds, attenuation coefficients, and reflection coefficients. To assess the impact of the elastic nonlocal parameter on the variations of phase speeds, attenuation coefficients, and amplitude ratios of the reflected waves, we present graphical representations. Notably, our observations indicate that all waves are influenced by the nonlocality of the medium. Longitudinal waves exhibit sensitivity to thermal parameters, whereas the shear-type wave remains independent of thermal effects. Furthermore, the presence of elastic nonlocality results in a reduction in the classical shear-type wave speed.

Crystalline deposit in lichens: Determination of crystals with regard to practical application in standard taxonomic studies

The presence of various crystal forms is quite often noticed in lichens from manytaxonomic groups. The crystalline deposit may be linked with the production of secondary metabolites or metal oxalates as well as to the uptake of calcium carbonate from the host substrate. Although the crystals are clearly visible under a microscope employing polarized light, their detailed determination is very difficult without the use of specialized equipment and analytical methods. On the other hand, it is not uncommon for the surface of lichen thalli to be covered with apparent pruina, which is formed by masses of calcium oxalate crystals. Regardless of their origin and distribution, crystalline products can perform an important functional role and enhance the adaptation of a given species to a specific habitat. Moreover, the presence and kind of crystals can be species-specific or characteristic of a certain group of species and, therefore, may constitute a useful diagnostic feature. We intended to examine the extent to which standard methods used in lichen taxonomy, such as solubility tests in chemical reagents, allow for the basic determination of crystals. We indicate the basic differences between various crystal deposits that can be observed inside or outside the lichen thallus. The presented results are based on examining selected specimens representing various lichen genera.

The New Paradigm of Russia’s International Financial Relations

The objective of this study is to explore the fundamental features of the emerging international financial framework in Russia, to pinpoint potential risks and central issues in its development. The distinctive characteristics of Russian companies’ international trade activities are explored through a comparative and economic-statistical analysis. The identification of risks was done by creating checklists using logical and analytical methods to organize information about the research topic. The risk analysis was based on the Ishikawa method (“fish bone”). The framework of Russia’s international financial interactions from 1991 to 2014 was centred on the goal of swiftly integrating the country into the global monetary and financial framework, fully embracing the standards set by the global power, while also acknowledging the increasing reliance on the collective West, which could potentially compromise national interests. The New Paradigm envisions a balanced integration of diverse subsystems and individual components — nations and groups of nations — within a cohesive geographical context. This framework envisions the enhancement of mutually beneficial international collaboration with allied nations and the development of novel settlement and payment systems, which are based on the utilization of national currencies and/or cutting-edge digital instruments.

Environmentally friendly screen-printed electrodes for the selective detection of 4-bromo-2,5-dimethoxyphenethylamine (2C-B) in forensic analysis.

In response to the growing need for sustainable analytical methods, this study explores the repurposing of screen-printed electrodes (SPEs) that would otherwise be discarded. This involves recoating the working electrode surface with a graphite (Gr) and chitosan (CTS) dispersion, creating a reusable SPE (SPE-Gr/CTS). Demonstrating its utility, SPE-Gr/CTS was employed for the detection of 4-bromo-2,5-dimethoxyphenethylamine (2C-B), a phenylethylamine commonly used for recreational proposes. Identifying 2C-B in fluid oral and seized samples is of great interest for forensic and toxicological applications. The 2C-B detection using SPE-Gr/CTS was optimized in Britton-Robinson buffer solution (0.1 mol L-1) at pH 2.0, employing square-wave adsorptive stripping voltammetry. The electrochemical behavior of 2C-B on SPE-Gr/CTS exhibited one irreversible oxidation and a reversible redox process. The proposed method presented a dynamic linear range for 2C-B determination (0.05 to 7.5 μmol L-1) with a low LOD (0.015 μmol L-1). Moreover, the stability of 2C-B electrochemical responses on SPE-Gr/CTS was confirmed using the same or different electrodes (N = 3), with a relative standard deviation of less than 5.0%. Interference studies with seventeen other illicit drugs and adulterants demonstrated that the proposed method is selective for 2C-B detection even in the presence of these substances. Real seized and oral fluid samples containing 2C-B were analyzed using this method, and the results were confirmed by LC-MS. The proposed device demonstrates to be an environmentally friendly and selective sensor for 2C-B detection in forensic analysis, offering a rapid and straightforward screening method for seized and biological samples. In addition, a portable and sensitive determination of 2C-B in forensic samples is presented with minimal sample consumption (50 μL).