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Tetracycline antibiotics (TCs) are among the most common broad spectrum antibiotic. Since 1940s, they have been widely used to prevent and treat human and animal infections, as well as growth promoters in animal feed. However, antibiotics are a double-edged sword. TCs can accumulate in humans and animals through the food chain, affecting human health and developing drug resistance. Therefore, TCs in food and environmental samples must be accurately analysed. In this review, analytical methods of TCs in various samples are summarised, focusing on novel sample pretreatment and detection techniques. [ABSTRACT FROM AUTHOR]

Background: Biological sample collection and data linkage can expand the utility of population health surveys. The present study investigates factors associated with population health survey respondents' willingness to provide biological samples and personal health information. Methods: Using data from the 2019 Centre for Addiction and Mental Health (CAMH) Monitor survey (n = 2,827), we examined participants' willingness to provide blood samples, saliva samples, probabilistic linkage, and direct linkage with personal health information. Associations of willingness to provide such information with socio-demographic, substance use, and mental health details were also examined. Question order effects were tested using a randomized trial. Results: The proportion of respondents willing to provide blood samples, saliva samples, probabilistic linkage, and direct linkage with personal health information were 19.9%, 36.2%, 82.1%, and 17%, respectively. Willingness significantly varied by age, race, employment, non-medical prescription opioid use (past year), cocaine use (lifetime), and psychological distress. Significant question order effects were observed. Respondents were more likely to be willing to provide a saliva sample when this question was asked first compared to first being asked for direct data linkage. Similarly, respondents were more likely to be willing to allow for probabilistic data linkage when this question was asked first compared to first being asked for a saliva sample. Conclusion: A lack of willingness to provide biological samples or permit data linkage may lead to representivity issues in studies which rely on such information. The presence of question order effects suggests that the willingness of respondents can be increased through strategic ordering of survey structures. [ABSTRACT FROM AUTHOR]

The resolution of a mega-electron-volt scanning transmission electron microscope (MeV-STEM) is primarily governed by the properties of the incident electron beam and angular broadening effects that occur within thick biological samples and microchips. A precise understanding and mitigation of these constraints require detailed knowledge of beam emittance, aberrations in the STEM column optics, and energy-dependent elastic and inelastic critical angles of the materials being examined. This simulation study proposes a standardized experimental framework for comprehensively assessing beam intensity, divergence, and size at the sample exit. This framework aims to characterize electron-sample interactions, reconcile discrepancies among analytical models, and validate Monte Carlo (MC) simulations for enhanced predictive accuracy. Our numerical findings demonstrate that precise measurements of these parameters, especially angular broadening, are not only feasible but also essential for optimizing imaging resolution in thick biological samples and microchips. By utilizing an electron source with minimal emittance and tailored beam characteristics, along with amorphous ice and silicon samples as biological proxies and microchip materials, this research seeks to optimize electron beam energy by focusing on parameters to improve the resolution in MeV-STEM/TEM. This optimization is particularly crucial for in situ imaging of thick biological samples and for examining microchip defects with nanometer resolutions. Our ultimate goal is to develop a comprehensive mapping of the minimum electron energy required to achieve a nanoscale resolution, taking into account variations in sample thickness, composition, and imaging mode. [ABSTRACT FROM AUTHOR]

Gelsemium elegans Benth alkaloids are the main components of G. elegans and can cause acute toxicosis or even death. Although several studies have reported methods for detecting G. elegans alkaloids, a high-throughput and environmental-friendly strategy for detection of multiple G. elegans alkaloids has not been realized. In this work, a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry method was developed for rapid detection of G. elegans alkaloids in human plasma and urine for diagnosis of poisoning. Multiple matrices and crystal spotting methods were evaluated to obtain stable and high peak intensities without "sweet spot". We verified the methodology and obtained excellent results. The matrix effects with different dilutions were compared and good recoveries and a low relative standard deviation were obtained with a 40-fold dilution. This method could shorten the analysis time and greatly reduce the consumption of chemical solvents. Furthermore, it could be applied to quantitative assessment of G. elegans alkaloid poisoning incidents. [ABSTRACT FROM AUTHOR]

Imaging at nanometre-scale resolution is indispensable for many scientific fields such as biology, chemistry, material science and nanotechnology. Scanning electron microscopes (SEM) are widely used as important tools for the nanometre-scale analysis of various samples. However, because of the vacuum inside the SEM, a typical analysis requires fixation of samples, a drying process, and staining with heavy metals. Therefore, there is a need for convenient and minimally invasive methods of observing samples in solution. Recently, we have developed a new type of impedance microscopy, multi-frequency impedance SEM (IP-SEM), which allows nanoscale imaging of various specimens in water with minimal radiation damage. Here, we report a new IP-SEM system equipped with a linear-array terminal, which allows eight tilted images to be observed in a single capture by applying eight frequencies of input signals to each electrode. Furthermore, we developed a three-dimensional (3D) reconstruction method based on the Simulated Annealing (SA) algorithm, which enables us to construct a high-precision 3D model from the 8 tilted images. The method reported here can be easily used for 3D structural analysis of various biological samples, organic materials, and nanoparticles.

Abstract Background Biological sample collection and data linkage can expand the utility of population health surveys. The present study investigates factors associated with population health survey respondents’ willingness to provide biological samples and personal health information. Methods Using data from the 2019 Centre for Addiction and Mental Health (CAMH) Monitor survey (n = 2,827), we examined participants’ willingness to provide blood samples, saliva samples, probabilistic linkage, and direct linkage with personal health information. Associations of willingness to provide such information with socio-demographic, substance use, and mental health details were also examined. Question order effects were tested using a randomized trial. Results The proportion of respondents willing to provide blood samples, saliva samples, probabilistic linkage, and direct linkage with personal health information were 19.9%, 36.2%, 82.1%, and 17%, respectively. Willingness significantly varied by age, race, employment, non-medical prescription opioid use (past year), cocaine use (lifetime), and psychological distress. Significant question order effects were observed. Respondents were more likely to be willing to provide a saliva sample when this question was asked first compared to first being asked for direct data linkage. Similarly, respondents were more likely to be willing to allow for probabilistic data linkage when this question was asked first compared to first being asked for a saliva sample. Conclusion A lack of willingness to provide biological samples or permit data linkage may lead to representivity issues in studies which rely on such information. The presence of question order effects suggests that the willingness of respondents can be increased through strategic ordering of survey structures.

Ion beam-induced heat damage in thermally low conductive specimens such as biological samples is gaining increased interest within the scientific community. This is partly due to the increased use of FIB-SEMs in biology as well as the development of complex materials, such as polymers, which need to be analyzed. The work presented here looks at the physics behind the ion beam–sample interactions and the effect of the incident ion energy (set by the acceleration voltage) on inducing increases in sample temperature and potential heat damage in thermally low conductive materials such as polymers and biological samples. The ion beam-induced heat for different ion beam currents at low acceleration voltages is calculated using Fourier’s law of heat transfer, finite element simulations, and numerical modelling results and compared to experiments. The results indicate that with lower accelerator voltages, higher ion beam currents in the nanoampere range can be used to pattern or image soft material and non-resin-embedded biological samples with increased milling speed but reduced heat damage.

Rapid, efficient, versatile, easy-to-use, and non-expensive analytical approaches are globally demanded for food analysis. Many ambient ionization approaches based on electrospray ionization (ESI) have been developed recently for the rapid molecular characterization of food products. However, those approaches mainly suffer from insufficient signal duration for comprehensive chemical characterization by tandem MS analysis. Here, a commercially available disposable gel loading tip is used as a low-cost emitter for the direct ionization of untreated food samples. The most important advantages of our approach include high stability, and durability of the signal (> 10 min), low cost (ca. 0.1 USD per run), low sample and solvent consumption, prevention of tip clogging and discharge, operational simplicity, and potential for automation. Quantitative analysis of sulfapyridine, HMF (hydroxymethylfurfural), and chloramphenicol in real sample shows the limit-of-detection 0.1 μg mL−1, 0.005 μg mL−1, 0.01 μg mL−1; the linearity range 0.1–5 μg mL−1, 0.005–0.25 μg mL−1, 0.01–1 μg mL−1; and the linear fits R2 ≥ 0.980, 0.991, 0.986. Moreover, we show that tip-ESI can also afford sequential molecular ionization of untreated viscous samples, which is difficult to achieve by conventional ESI. We conclude that tip-ESI–MS is a versatile analytical approach for the rapid chemical analysis of untreated food samples. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To assess the temperature stability of an autodefrost freezer commonly used in veterinary practices, whether the use of a Styrofoam cooler within the freezer provides temperature stability, and the ease of use of a remote monitoring system for the notification of temperature elevations. ANIMALS: None. METHODS: Temperature in the freezer and 2 Styrofoam coolers were assessed with remote monitoring thermometers every 15 minutes. Temperature values were monitored from October 11 to December 18, 2023 (for a 68-day period). Data analysis focused on temperatures for the freezer exceeding 0 °C and the elevations in temperatures within the coolers relative to the freezer. RESULTS: The freezer had an increase in temperature approximately every 16 hours. Over 68 days, the freezer had a temperature greater than 0 °C 27 times, representing 26 separate elevations. The Styrofoam coolers within the freezer never registered a temperature higher than -5 °C. Elevations in temperature within the freezer were larger in magnitude than temperature elevations within the coolers, which showed smaller-magnitude changes in temperature. [ABSTRACT FROM AUTHOR]

In this study, continuous-flow membrane microextraction was connected online with a high-performance liquid chromatography-UV detector for the pre-concentration and high clean-up of papaverine and codeine in biological samples. The extraction cell was designed with donor and acceptor chambers separated by a sheet membrane. By adjusting the pH of the donor phase (10 mL, pH 11), the analyte molecules were extracted into the supported liquid membrane (SLM) (15 µL of 1-octanol). The donor solution was circulated through the donor chamber using a peristaltic pump and magnetically agitated by a bar stirrer placed near the membrane, enhancing the diffusion and convection flow of the targeted drugs from the donor solution to the SLM. Subsequently, by adjusting the acceptor solution to an acidic pH of 2 (100 µL), the drugs in ionic form were reversely extracted into the acceptor phase. The procedure exhibited desirable relative standard deviation of less than 3.70%, linear ranges of 7–600 ng mL−1 for codeine and 2.0–600 ng mL−1 for papaverine, and limits of detection of 2.0 ng mL−1 for codeine and 0.6 ng mL−1 for papaverine. The design of the extraction cell significantly improved the performance for determining targeted drugs in complex matrices such as plasma and urine. [ABSTRACT FROM AUTHOR]

In this investigation, a novel electrochemical approach employing a bare carbon paste electrode (CPE) has been devised for the sensitive and expeditious quantification of the tyrosine kinase inhibitor vandetanib (VAN). VAN, a pivotal anti-tumor agent employed in various cancer types, notably medullary thyroid cancer, manifested an irreversible oxidation peak at approximately +1.17 V (vs. Ag/AgCl, 3 M NaCl) in 0.1 M HNO3, elucidated through cyclic voltammetry. The electrode reaction was determined to proceed via controlled adsorption. The study meticulously examined the influence of anionic surfactant sodium dodecyl sulfate (SDS), instrumental parameters, pH fluctuations, and the composition of the supporting electrolyte on the oxidation peak of VAN. Remarkably, the sensitivity of stripping voltammetric measurements markedly augmented upon the inclusion of 9 × 10−4 M SDS. Employing optimized parameters for SW-AdSV (square-wave adsorptive stripping voltammetry), the bare CPE demonstrated exceptional linearity within the dynamic ranges of 1.05×10−7 – 1.6×10−5 M for VAN. The limit of detection and limit of quantification were established at 2.7×10−8 and 9.0×10−8 M for VAN, respectively. Furthermore, the developed electrochemical methodology was effectively applied for the detection of VAN in spiked model serum samples. [ABSTRACT FROM AUTHOR]

Iodoacetic acid (IAA) is a halogenated disinfection by-product of growing concern due to its high cytotoxicity, genotoxicity, endocrine disruptor effects, and potential carcinogenicity. However, the data on distribution and excretion of IAA after ingestion by mammals are still scarce. Here, we developed a reliable and validated method for detecting IAA in biological specimens (plasma, urine, feces, liver, kidney, and tissues) based on modified QuEChERS sample preparation combined with gas chromatography-tandem triple quadrupole mass spectrometry (GC–MS/MS). The detection method for IAA exhibited satisfactory recovery rates (62.6–108.0%) with low relative standard deviations (RSD < 12.3%) and a low detection limit for all biological matrices ranging from 0.007 to 0.032 ng/g. The study showed that the proposed method was reliable and reproducible for analyzing IAA in biological specimens. It was successfully used to detect IAA levels in biological samples from rats given gavage administration. The results indicated that IAA was found in various tissues and organs, including plasma, thyroid, the liver, the kidney, the spleen, gastrointestinal tract, and others, 6 h after exposure. This study provides the first data on the in vivo distribution in and excretion of IAA by mammals following oral exposure. [ABSTRACT FROM AUTHOR]

Carnitines, essential for human metabolism and fatty acid transport, are primarily obtained from the diet. Inadequate synthesis or intake can lead to serious metabolic disorders, which may result in fatal outcomes. Therefore, the accurate determination of carnitines in both food and biological samples is of high importance. However, these samples are inherently complex and require meticulous preparation procedures before determination. This step is critical for enhancing the sensitivity and precision of the detection process. Moreover, the selection of an appropriate detection method is crucial and must match the analytes’ characteristics. For example, since carnitines lack chromophores for spectroscopic detection, they require derivatization to become spectroscopically visible. Among the various methods available for carnitine determination, chromatography and mass spectrometry are the most prominent, owing to their superior selectivity and sensitivity. Nonetheless, there seems to be a lack of comprehensive reviews on this subject. Consequently, this article aims to compile the latest advancements in analytical methodologies for carnitines over the past decade (2013–2023), with a particular emphasis on the crucial contributions of chromatography and mass spectrometry techniques. This review provides crucial insights for metabolic research, underpinning advances in understanding carnitine's metabolic roles. It aims to highlight current innovations in carnitine analysis and inspire future breakthroughs impacting nutrition, diagnostics, and therapy.

Abstract This study analyzed the relationship between urine concentrations of phthalate metabolites (UCOM) and personal care products (PCPs) used in adults and examined the change in UCOM according to the usage frequency of PCPs based on raw data from the 3rd Korean National Environmental Health Survey conducted between 2015 and 2017. The relationship between PCP use frequency and UCOM was analyzed using multiple regression analysis, adjusting for baseline factors. The regression model consisted of a Crude Model with log-transformed UCOM before and after adjustment for urine creatinine concentrations. Model 1 was additionally adjusted for age, sex, and obesity, while Model 2 was additionally adjusted for smoking, alcohol consumption, pregnancy history, average monthly income of the household, and PCP exposure within the past 2 days. PCP usage frequency was significantly associated with the UCOM without adjustment for urine creatinine and correlated with demographic characteristics, urine creatinine concentration, and PCP exposure within the past 2 days. This study on exposure to urinary phthalates will play a crucial role in Korean public health by aligning with the fundamentals of research priorities and providing representative data on phthalate exposure for conducting population-level studies.

The resolution of a mega-electron-volt scanning transmission electron microscope (MeV-STEM) is primarily governed by the properties of the incident electron beam and angular broadening effects that occur within thick biological samples and microchips. A precise understanding and mitigation of these constraints require detailed knowledge of beam emittance, aberrations in the STEM column optics, and energy-dependent elastic and inelastic critical angles of the materials being examined. This simulation study proposes a standardized experimental framework for comprehensively assessing beam intensity, divergence, and size at the sample exit. This framework aims to characterize electron-sample interactions, reconcile discrepancies among analytical models, and validate Monte Carlo (MC) simulations for enhanced predictive accuracy. Our numerical findings demonstrate that precise measurements of these parameters, especially angular broadening, are not only feasible but also essential for optimizing imaging resolution in thick biological samples and microchips. By utilizing an electron source with minimal emittance and tailored beam characteristics, along with amorphous ice and silicon samples as biological proxies and microchip materials, this research seeks to optimize electron beam energy by focusing on parameters to improve the resolution in MeV-STEM/TEM. This optimization is particularly crucial for in situ imaging of thick biological samples and for examining microchip defects with nanometer resolutions. Our ultimate goal is to develop a comprehensive mapping of the minimum electron energy required to achieve a nanoscale resolution, taking into account variations in sample thickness, composition, and imaging mode.

A method for the determination of trace levels of silicon from biological materials by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. The volatility of water-soluble silicon species, hexafluorosilicic acid (H2SiF6), and sodium metasilicate (Na2SiO3) was investigated by evaporating respective solutions (50 µg/mL silicon) in nitric acid (HNO3), nitric acid + hydrochloric acid (HNO3 + HCl), and nitric acid + hydrochloric acid + hydrofluoric acid (HNO3 + HCl + HF) at 120 °C on a hot-block to near dryness. The loss of silicon from H2SiF6 solutions was substantial (>99%) regardless of the digestion medium. Losses were also substantial (>98%) for metasilicate solutions heated in HNO3 + HCl + HF, while no significant loss occurred in HNO3 or HNO3 + HCl. These results show that H2SiF6 species were highly volatile and potential losses could confound accuracy at trace level determinations by ICP-MS if digestates prepared in HF are heated to eliminate HF. Among the various matrices comprising major elements, sodium appeared to be effective in reducing silicon loss from H2SiF6 solutions. Excess sodium chloride (NaCl) matrix provided better stability, improving silicon recoveries by up to about 80% in evaporated HF digestates of soil and mine waste samples, but losses could not be fully prevented. To safely remove excess acids and circumvent the adverse effects of excess HF (e.g., risk of high Si background signals), a two-step digestion scheme was adopted for the preparation of biological samples containing trace silicon levels. A closed-vessel digestion was performed either in 4 mL of concentrated HNO3 and 1 mL of concentrated HCl or 4 mL of concentrated HNO3, 1 mL of concentrated HCl and 1 mL of concentrated HClO4 on a hot plate at 140 °C. Digestates were then evaporated to incipient dryness at 120 °C to remove the acids. A second closed-vessel digestion was carried out to dissolve silicates in 0.5 mL of concentrated HNO3 and 0.5 mL of concentrated HF at 130 °C. After digestion, digestates were diluted to 10 mL. The solution containing about 5% HNO3 and 5% HF was directly analyzed by ICP-MS equipped with an HF-inert sample introduction system. The limit of detection was about 110 µg/L for 28Si when using the Kinetic Energy Discrimination (KED) mode. The method was used to determine silicon in various plant and tissue certified reference materials. Data were acquired for 28Si using KED and standard (STD) modes, and 74Ge and 103Rh as internal standard elements. There was not any significant difference between the accuracy and precision of the results obtained with 74Ge and 103Rh within the same measurement mode. Precision, calculated as relative standard deviation for four replicate analyses, varied from 5.3 (tomato leaves) to 21% (peach leaves) for plant and from 2.2 (oyster tissue) to 33% (bovine liver) for tissue SRM/CRMs. Poor precision was attributed to material heterogeneity and the large particle size distribution. An analysis of lung tissue samples from those with occupational exposure to silica dust revealed that tissues possessed substantial levels of water-soluble silicates, but the most silicon was present in the particulate matter fraction. [ABSTRACT FROM AUTHOR]

Using fecal microbial community profiles through sequencing approaches helps to unravel the intimate interplay between health, wellness, and diet in wild animals with their environment. Ensuring the proper preservation of fecal samples before processing is crucial to ensure reliable results. In this study, we evaluated the efficiency of two different preservation methods, considering the following criteria: DNA yield, quality and integrity, and microbial community structure based on Oxford Nanopore amplicon sequencing of the V3-V4 region of bacterial 16S rRNA and protozoa 18S rRNA genes. Eighteen matched pairs of mammalian fecal samples were collected and transported in 99.8% ethanol and lysis buffer; processing occurred between 55 and 461 days post-collection. Wilcoxon signed-rank tests were used to analyze quantitative measurements for paired samples. The A260/280 ratio, a measure of nucleic acid purity, was assessed descriptively for each media, and the Bartlett test evaluated dispersion of this ratio. A Fisher test was performed to compare the number of positive reactions for DNA extraction or PCR amplification of the 16S and 18S rRNA genes between both media. The concentration of total DNA and amplicons, as well as the number of reads obtained in sequencing, was significantly higher in the samples preserved with lysis buffer compared to ethanol, with magnitudes up to three times higher. Electrophoretic analysis of total DNA and amplicons further confirmed superior DNA integrity in lysis buffer preserved samples. The A260/280 values obtained using the lysis buffer were of optimal purity (mean: 1.92) and with little dispersion (SD: 0.27); on the other hand, the ethanol samples also presented an excellent average quality (mean: 1.94), but they were dispersed (SD: 1.10). For molecular studies using mammalian feces, the lysis buffer reagent proved to be a reliable solution for their collection, conservation, and storage.

Introduction. Up-to-date data and full characterization of circulating ASFV isolates play a crucial role in virus eradication and control in endemic regions and countries. The aim of the study was to evaluate and characterize the molecular and biological properties of the ASFV isolate ASF/Tatarstan 20/WB-12276, conduct phylogenetic analysis, and compare the results with isolates circulating in Europe and Asia. Materials and methods. For bioassay, eight heads of the Large White pigs weighing 1520 kg/head were used. Detection of specific anti-ASFV antibodies by ELISA and immunoperoxidase method. Detection of ASFV genome was performed by qPCR. Isolation of ASF/Tatarstan 20/WB-12276 and determination of titer were performed in pig spleen cell culture. Sequencing was carried out by the Sanger method. Results. The virus was characterized as highly virulent and capable of causing acute to subacute forms of ASF. Phylogenetic analysis revealed substitutions in the genome of the ASF/Tatarstan 20/WB-12276 isolate (IGR/I73R-I329L and I267L markers) that supported the clustering of the studied variant with isolates prevalent in most of Europe and Asia. Conclusion. For the first time, the molecular and biological properties of the ASF/Tatarstan 20/WB-12276 virus isolate taken from a wild boar shot on the territory of the Republic of Tatarstan were studied and analyzed.

Plastic products are widely used in various fields, and the discarded plastics in the environment can be degraded into microplastics (MPs) or even nanoplastics (NPs), which significantly increases the risk of organism exposure. MPs/NPs have been found in aquatic organisms, birds of prey, and even humans. The detection of plastic particles in biological samples is more complicated than that in environmental samples. Biological samples are mainly composed of various organic substances such as proteins and lipids, which makes the pretreatment process particularly critical. Effective detection and accurate quantification of MPs/NPs are crucial to health risk assessment. In this paper, the exposure levels and composition of MPs/NPs in different tissues and organs of the human body, aquatic organisms, and birds of prey were reviewed. The digestion of biological samples (acids, bases, enzymes, and hydrogen peroxide digestion protocols) and MPs/NPs identification methods (spectroscopy and chromatography) were compared and their advantages and disadvantages were assessed, providing a methodological basis for plastic exposure risk assessment and pollution control.

Background: Large-scale longitudinal studies with biological samples are needed to examine the associations between prenatal cannabis use and birth and developmental outcomes. Objectives: The aim of this study was to understand the feasibility and acceptability of collecting umbilical cord tissue for the purpose of cannabis use testing in a community sample. Design: This is a mixed methods research study consisted of a prospective cohort study and a qualitative descriptive study. Methods: This study was conducted in Vancouver, British Columbia between January 2021 and August 2022. Participants were recruited during pregnancy, and the umbilical cord tissues were collected at birth and tested for the presence of cannabinoids. After the completion of the study, participants completed an online open-ended questionnaire about their overall experience. Data were analyzed using descriptive and thematic analyses. Results: Among the 85 eligible individuals, 57 people (67%) consented to the study. The cord tissue was collected for 39 participants (68.4%). The collection rates for participants with vaginal, elective, and emergency cesarean delivery were 73.0%, 71.4%, and 53.8%, respectively, and for those with spontaneous and induced labor were 81.5% and 50%, respectively. Four (7.0%) and seven participants (12.3%) reported prenatal cannabis use in direct and probing self-report questions, respectively. The agreement between any self-report and cord tissue test was moderate (kappa 0.53, 95% confidence interval 0.06–0.99). Qualitative findings were classified into five themes. Conclusion: The collection of cord tissue was perceived acceptable by most participants. Implementation of collection protocols for complex labors, a central hospital unit to liaise direct communications and active participants' involvement might increase the feasibility of future studies. [ABSTRACT FROM AUTHOR]

The novel electrochemical sensor was employed for the investigation of the uricosuric drug sulfinpyrazone (SLF), which is administered orally to treat gout and prevent stone formations. SLF is toxic to the liver and increases the risk of Stevens-Johnson syndrome and toxic epidermal necrolysis, which are life-threatening conditions. It is crucial to avoid aspirin, salicylates, and similar salicylic acid derivatives when taking uricosuric drugs, as salicylates can inhibit tubular uric acid secretion, especially at lower doses. Thus, determining SLF is highly significant. In the pursuit of intensive care and interactions involving SLF, an r-GO@CPE (reduced graphene oxide modified carbon paste electrode) was employed for the study of SLF. Various characterization techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray diffraction spectrum (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and electron impedance spectroscopy (EIS), were utilized to analyse the electrode modifier. The resulting r-GO@CPE has an enriched electroactive surface area, a high standard heterogeneous rate constant (ket), and a small charge resistance (Rct) as compared with the Carbon paste electrode, which authenticates its good catalytic activity. The analytical investigation of SLF was achieved through voltametric techniques such as cyclic & square wave voltammetry (CV & SWV). Optimal results were attained at a pH of 9.2, revealing an oxidation peak within the potential range of 0.2–1.2 V. SWV was employed for the quantitative estimation of SLF, yielding a limit of detection (LOD) and a limit of quantification (LOQ) of 1.10 × 10−8 M and 3.6 × 10−8 M respectively. This novel approach was also applied to determine SLF concentrations in both biological, water & pharmaceutical samples.

Abstract Catecholamines (CAs), including adrenaline, noradrenaline, and dopamine, are neurotransmitters and hormones that play a critical role in regulating the cardiovascular system, metabolism, and stress response in the human body. As promising methods for real-time monitoring of catecholamine neurotransmitters, LC-MS detectors have gained widespread acceptance and shown significant progress over the past few years. Other detection methods such as fluorescence detection, colorimetric assays, surface-enhanced Raman spectroscopy, and surface plasmon resonance spectroscopy have also been developed to varying degrees. In addition, efficient pretreatment technology for CAs is flourishing due to the increasing development of many highly selective and recoverable materials. There are a few articles that provide an overview of electrochemical detection and efficient enrichment, but a comprehensive summary focusing on analytical detection technology is lacking. Thus, this review provides a comprehensive summary of recent analytical detection technology research on CAs published between 2017 and 2022. The advantages and limitations of relevant methods including efficient pretreatment technologies for biological matrices and analytical methods used in combination with pretreatment technology have been discussed. Overall, this review article provides a better understanding of the importance of accurate CAs measurement and offers perspectives on the development of novel methods for disease diagnosis and research in this field. [ABSTRACT FROM AUTHOR]

Mass spectrometry imaging (MSI) is a powerful label‐free analysis technique that can provide simultaneous spatial distribution of multiple compounds in a single experiment. By combining the sensitive and rapid screening of high‐throughput MS with spatial chemical information, metabolite analysis and morphological characteristics are presented in a single image. MSI can be used for qualitative and quantitative analysis of metabolic profiles and it can provide visual analysis of spatial distribution information of complex biological and microbial systems. Matrix‐assisted laser desorption ionization, laser ablation electrospray ionization and desorption electrospray ionization are commonly used in MSI. Here, we summarize and compare these three technologies, as well as the applications and prospects of MSI in metabolomics. [ABSTRACT FROM AUTHOR]

Measurements of microplastics in environmental and biological samples can be overestimated because of contaminants introduced during the analytical process. Knowledge of the potential sources and frequency of contamination during analysis is required to develop a protocol to prevent analytical errors. In this study, potential sources of contamination in the laboratory analysis of biological samples were evaluated, and reliable, inexpensive measures to prevent contamination were tested. Glass fibre filters, water samples, air samples, and chemicals [Fenton's reagent (H2O2 and FeSO4), and ZnCl2] were tested for the presence of contaminants. Particulate contamination, including microplastics, was found in all samples when tested before application of any preventative measures. The following measures were evaluated for preventing contamination: (1) filtration of the water and chemical solutions using a glass fibre filter, (2) pre-combustion of the glass fibre filters, and (3) use of a clean booth for experimental work. The preventative measures reduced the levels of microplastics in all samples by 70–100%. The dominant polymers identified by Fourier transform infrared spectroscopy were polyethylene terephthalate, cellulose fibre (rayon), polystyrene, polyacrylonitrile, and polyethylene. With the preventative measures, the number of microplastics in the laboratory blanks was low enough to set the limit of detection to < 1. This limit of detection would be suitable for examination of microplastics contamination at the individual organism level, even at trace levels. Preventative countermeasures are essential to reduce overestimation of microplastics in biological samples and can be implemented at low cost. [ABSTRACT FROM AUTHOR]

A sensitive, rapid, and inexpensive electrochemical method with an unmodified carbon paste electrode (CPE) was developed for the first time for voltammetric determination of poly(ADP-Ribose) polymerase (PARP) inhibitor olaparib (OLA) used in the treatment of advanced ovarian cancer, metastatic breast, and prostate cancer. OLA showed an irreversible oxidation peak at physiological pH (pH 7.4) at approximately + 1.31 V by the cyclic voltammetry technique. Using the suitable values of square-wave voltammetric parameters, the CPE showed good linearity in the concentration ranges of 5.8 × 10–7–4.6 × 10–5 mol dm−3 for OLA. The limit of detection and limit of quantification were determined to be 2.9 × 10–8 and 9.7 × 10–8 mol dm−3 for OLA, respectively. Besides its high stability and reproducibility, the response of OLA at CPE was not affected in the presence of dopamine, uric acid, and ascorbic acid. The developed electrochemical method has been successfully applied for the detection of OLA in the spiked human urine sample. [ABSTRACT FROM AUTHOR]

Acetylcholine (ACh) is one of the most crucial neurotransmitters of the cholinergic system found in vertebrates and invertebrates and is responsible for many processes in living organisms. Disturbances in ACh transmission are closely related to dementia in Alzheimer's and Parkinson's disease. ACh in biological samples is most often determined using chromatographic techniques, radioenzymatic assays, enzyme-linked immunosorbent assay (ELISA), or potentiometric methods. An alternative way to detect and determine acetylcholine is applying spectroscopic techniques, due to low limits of detection and quantification, which is not possible with the methods mentioned above. In this review article, we described a detailed overview of different spectroscopic methods used to determine ACh with a collection of validation parameters as a perspective tool for routine analysis, especially in basic research on animal models on central nervous system. In addition, there is a discussion of examples of other biological materials from clinical and preclinical studies to give the whole spectrum of spectroscopic methods application. Descriptions of the developed chemical sensors, as well as the use of flow technology, were also presented. It is worth emphasizing the inclusion in the article of multi-component analysis referring to other neurotransmitters, as well as the description of the tested biological samples and extraction procedures. The motivation to use spectroscopic techniques to conduct this type of analysis and future perspectives in this field are briefly discussed. [ABSTRACT FROM AUTHOR]

ABSTRACT Here, we aimed to compare the effects of different preservation methods on outcomes of fecal microbiota. We evaluated the effects of different preservation methods using stool sample preservation experiments for up to 1 year. The stool samples from feces of healthy volunteers were grouped based on whether absolute ethanol was added and whether they were hypothermically preserved. Besides, we performed a systematic review to combine current fecal microbiota preservation evidence. We found that Proteobacteria changed significantly and Veillonellaceae decreased significantly in the 12th month in the room temperature + absolute ethanol group. The four cryopreservation groups have more similarities with fresh sample in the 12 months; however, different cryopreservation methods have different effects on several phyla, families, and genera. A systematic review showed that the Shannon diversity and Simpson index of samples stored in RNAlater for 1 month were not statistically significant compared with those stored immediately at −80°C (P = 0.220 and P = 0.123, respectively). The −80°C refrigerator and liquid nitrogen cryopreservation with 10% glycerine can both maintain stable microbiota of stool samples for long-term preservation. The addition of absolute ethanol to cryopreserved samples had no significant difference in the effect of preserving fecal microbial characteristics. Our study provides empirical insights into preservation details for future studies of the long-term preservation of fecal microbiota. Systematic review and meta-analysis found that the gut microbiota structure, composition, and diversity of samples preserved by storage methods, such as preservation solution, are relatively stable, which were suitable for short-term storage at room temperature. IMPORTANCE The study of gut bacteria has become increasingly popular, and fecal sample preservation methods and times need to be standardized. Here, we detail a 12-month study of fecal sample preservation, and our study provides an empirical reference about experimental details for long-term high-quality storage of fecal samples in the field of gut microbiology research. The results showed that the combination of −80°C/liquid nitrogen deep cryopreservation and 10% glycerol was the most effective method for the preservation of stool samples, which is suitable for long-term storage for at least 12 months. The addition of anhydrous ethanol to the deep cryopreserved samples did not make a significant difference in the preservation of fecal microbiological characteristics. Combined with the results of systematic reviews and meta-analyses, we believe that, when researchers preserve fecal specimens, it is essential to select the proper preservation method and time period in accordance with the goal of the study.

Objective: To assess the thorium exposure of the mine workers and the public to a typical rare earth mine and estimate the resultant committed effective dose to them. Methods: A total of 79 volunteers were selected in this survey, including 69 mine workers and 10 local residents living about 4 ​km away from the mine site. Urinary samples were collected from 79 volunteers, with 65 hair samples from 57 workers and 8 local residents. The thorium concentrations in urinary and hair samples were determined by using inductively coupled plasma mass spectrometry. The committed effective doses were estimated based on the urinary samples collected and the parameters as recommended by ICRP Publication 137. Results: Thorium concentrations in the samples from the workers ranged from 19.0 to 2388.8 ​ng/g in hair with median of 149.8 ​ng/g, and in urine 18.3–906.1 ​ng/L with median of 59.6 ​ng/L, respectively. The median values of thorium concentrations were 11.8 ​ng/g in hair and 32.40 ​ng/L in urine for the public respectively. The thorium concentrations in urinary and hair samples of the workers were not only higher than those of the residents in the local area, but also than those of non-occupationally exposed populations as reported. The median values of committed effective dose were estimated to be 1.51 ​mSv for the workers and 781 ​μSv for the local residents, respectively. Conclusions: The residents in the local area, and especially the workers, have been subject to long term thorium exposure. More attention should be paid to the radiological hazards of thorium to the workers and local residents.

• A new sorbent was prepared by combining MOF, COF, magnetic nanoparticles, and MIP. • The sorbent was utilized for the selective extraction of montelukast from biological samples. • The LOD and LOQ were achieved at levels of ng mL-1. • The montelukast was detected by the HPLC-MS/MS system. In this study, a new magnetic nanocomposite comprised of a molecularly imprinted polymer, metal organic framework, and covalent organic framework was synthesized and used in the dispersive solid-phase extraction of montelukast from plasma and urine samples. The extracted analyte was then analyzed using liquid chromatography-tandem mass spectrometry. The drug extraction process involved adding the synthesized nanocomposite to the biological sample. After vortexing, the solid particles were collected using an external magnet. The adsorbed analyte was subsequently eluted with acetonitrile. By combining of the developed method with liquid chromatography-tandem mass spectrometry, low limits of detection (0.04 and 0.05 ng mL−1 in urine and plasma, respectively) and quantification (0.14 and 0.16 ng mL−1 in urine and plasma, respectively), a wide linear range (0.14-300 and 0.16-300 ng mL−1 in urine and plasma, respectively), acceptable relative standard deviations for intra- and inter-day precisions (≤6.3 %), and good extraction recoveries (75 and 72 % in urine and plasma samples, respectively) were achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • NIR photothermal lens spectrometer (PTLS) used for determination phosphate ions. • NIR PTLS is highly sensitive to phosphate with the detectability amount to 33 pg. • Phosphate ions can be analyzed by using PTLS in beverage and blood serum samples. • NIR PTLS with microfluidic cell can be used for phosphate detection in 50 µL samples. In this work, photothermal lens spectrophotometer (PTLS) with crossed-beam configuration pumped by a laser diode (850 nm) was used for determination of soluble phosphorus exists mainly in the form of orthophosphate (PO 4 3−) in nonalcoholic beverage and human blood serum samples. The determination was carried out after complexation reaction between blue molybdenum and phosphate in aqueous solution. UV–vis spectrophotometry was used by measuring absorption in the near infrared region (815 nm) for optimizing the complex formation time, concentrations of reducing agent and sulfuric acid. The UV–vis absorption measurements showed that the calibration curve was obtained in the concentration ranges of 0.5–80 mg L−1 with a linear correlation coefficient of 0.98 and a detection limit of 0.2 mg L−1. Then, PTLS at a wavelength of 850 nm after optimizing the device conditions (flow rate, excitation laser power and interrupting frequency) was used for phosphate determination. The calibration curve in the concentration range of 11–1000 µg L−1 has a correlation coefficient of 0.98 and a detection limit of 4 µg L−1. The achieved detection limit was about 50 times better than NIR absorption spectrometry using a conventional 1 cm sample cell. In PTLS with the 3 μL microfluidic cell experimental detectability amount of phosphate is 33 picogram, while in UV–vis-NIR method this amount is 1.5 µg. [ABSTRACT FROM AUTHOR]

New analytical strategies for metal-binding protein facilitate researchers learning about how metals play a significant role in life. Laser ablation–inductively coupled plasma mass spectrometry (LA-ICP-MS) offers many advantages for the metal analysis of biological samples and shows a promising future in protein analysis, but recent advances in LA-ICP-MS-based strategies for identifying metal-binding proteins via endogenous metals remain less updated yet. To present the current status in this field, the main analytical strategies for metal-binding proteins with LA-ICP-MS are reviewed here, including in situ analysis of biospecimens and ex situ analysis with gel electrophoresis. A critical discussion of challenges and future perspectives is also given. Multifarious laser ablation–inductively coupled plasma mass spectrometry (LA-ICP-MS)-based strategies have been developed and applied to investigate the metal-binding proteins in biospecimens in situ or through gel electrophoresis ex situ over the past decades, facilitating researchers disclosing how essential metals are implicated in life or what proteins toxic metals will target. [ABSTRACT FROM AUTHOR]

A novel chiral derivatization liquid chromatography method, combined with fluorous separation technology, was developed in this study. N‐(Perfluoroalkylcarbonyl)‐l‐proline succinimidyl ester, synthesized from perfluoroalkylcarboxylic acids (C5F11COOH, C7F15COOH, or C9F19COOH), L‐proline, and N‐hydroxysuccinimide, was used as the chiral derivatization reagent. In this study, chiral compounds containing perfluoroalkyl groups were reacted with enantiomeric amino analytes to form diastereomeric derivatives, which can be chirally separated on a conventional liquid chromatography column. Furthermore, by using a fluorous‐phase liquid chromatography column, the derivatives were strongly retained owing to the fluorous affinity and could be separated from the contaminating components in the matrix. In this study, amino groups were selected as derivatization targets, and (R,S)‐1‐phenylethylamine was used as the model compound. The effect of the perfluoroalkyl chain length of the chiral reagent on enantiomeric separation was investigated using fluorous‐phase and reversed‐phase liquid chromatography columns and the optimal perfluoroalkyl chain length was determined. (R,S)‐1‐Phenylethylamine was added to human serum and urine samples to confirm separation from the contaminants. Consequently, chiral separation was achieved without contaminant detection. [ABSTRACT FROM AUTHOR]

Restricted-access materials (RAMs) allow biological samples to directly enter the chromatographic column for analysis owing to the steric exclusion function ability for biomolecules and extraction function for small-molecule analytes, which promoting the development of rapid, efficient, and automated in vivo drug analysis. Few reports on chiral RAMs that have been used to analyze enantiomers and positional isomers in serum by direct injection in currently. In this study, a chiral porous organic cage material RCC3 was innovatively introduced into the inner surface of silica gel and modified the outer surface with polyethylene glycol to prepare a novel type of chiral RAM-RCC3, and reported the use of chiral RAM-RCC3 as a stationary phase for the separation of chiral compounds and positional isomers in blank serum using high-performance liquid chromatography. The novel RAM-RCC3 column exhibited good performance in the online analysis of nine enantiomers and five positional isomers in serum samples. The effects of analyte mass, temperature, and composition of the mobile phase on the separation of o-, m-, and p-nitrophenol in serum samples using the RAM-RCC3 column were also investigated. Even after 300 injections, the RAM-RCC3 column exhibited good reproducibility and stability. These results indicate the potential of the chiral RAM-RCC3 column as a stationary phase for direct injection analysis of both chiral separation and positional isomers in biological samples, which also rendering it suitable to be further developed as a new type of RAM for online analysis of various small molecules in biological samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Imaging at nanometre-scale resolution is indispensable for many scientific fields such as biology, chemistry, material science and nanotechnology. Scanning electron microscopes (SEM) are widely used as important tools for the nanometre-scale analysis of various samples. However, because of the vacuum inside the SEM, a typical analysis requires fixation of samples, a drying process, and staining with heavy metals. Therefore, there is a need for convenient and minimally invasive methods of observing samples in solution. Recently, we have developed a new type of impedance microscopy, multi-frequency impedance SEM (IP-SEM), which allows nanoscale imaging of various specimens in water with minimal radiation damage. Here, we report a new IP-SEM system equipped with a linear-array terminal, which allows eight tilted images to be observed in a single capture by applying eight frequencies of input signals to each electrode. Furthermore, we developed a three-dimensional (3D) reconstruction method based on the Simulated Annealing (SA) algorithm, which enables us to construct a high-precision 3D model from the 8 tilted images. The method reported here can be easily used for 3D structural analysis of various biological samples, organic materials, and nanoparticles., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Mercury (Hg) and its compounds are highly toxic for humans and ecosystems, and their chemical forms determine both their behavior and transportation as well as their potential toxicity for human beings. Determining the various species of an element is therefore more crucial than understanding its overall concentration in samples. For this reason, several studies focus on the development of new analytical techniques for the identification, characterization, and quantification of Hg compounds. Commercially available, hyphenated technology, such as HPLC-ICP-MS, supports the rapid growth of speciation analysis. This review aims to summarize and critically examine different approaches for the quantification of mercury species in different samples using HPLC-ICP-MS. The steps preceding the quantification of the analyte, namely sampling and pretreatment, will also be addressed. The scenarios evaluated comprehend single and multi-element speciation analysis to create a complete guide about mercury content quantification.

African swine fever virus (ASFV) is a global threat to swine production and sustainable pork supply. Without a commercially available vaccine, prevention of ASFV entry and spread is reliant on biosecurity and early detection of infection. Although ASFV ingestion in swill or feed by naïve pigs is a likely route of initial introduction, controlled experimental studies rarely utilize natural consumption as the infection route. In the current study, we utilized biological samples collected from pigs 5 days after natural consumption of ASFV in feed and liquid to assess diagnostic sensitivity for early detection of virus infection. Biological samples (serum, spleen, lymph nodes, tonsils, and faeces) were assessed for the presence of ASFV using quantitative PCR and virus isolation. Statistical methods modelled the detection sensitivity of each sample type with each diagnostic assay in individual samples. Our results provide important information that can be incorporated into ASFV surveillance programs. [ABSTRACT FROM AUTHOR]

• Analytical techniques for quantifying cannabinoids in biological samples are explored. • Recent advances in biological sample preparation for cannabinoids are illustrated. • Challenges in the analysis of endocannabinoids and phytocannabinoids are discussed. • The advantages of chromatography analysis of cannabinoids are reported. • Latest innovations and future perspectives in cannabinoid analysis are presented. Endocannabinoid system, including endocannabinoid neurotransmitters (eCBs), has gained much attention over the last years due to its involvement with the pathophysiology of diseases and the potential use of Cannabis sativa (marijuana). The identification of eCBs and phytocannabinoids in biological samples for forensic, clinical, or therapeutic drug monitoring purposes constitutes a still significant challenge. In this scoping review, the recent advantages, and limitations of the eCBs and phytocannabinoids quantification in biological samples are described. Published studies from 2018-2023 were searched in 8 databases, and after screening and exclusions, the selected 38 articles had their data tabulated, summarized, and analyzed. The main characteristics of the eCBs and phytocannabinoids analyzed and the potential use of each biological sample were described, indicating gaps in the literature that still need to be explored. Well-established and innovative sample preparation protocols, and chromatographic separations, such as GC, HPLC, and UHPLC, are reviewed highlighting their respective advantages, drawbacks, and challenges. Lastly, future approaches, challenges, and tendencies in the quantification analysis of cannabinoids are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] Carnitines, essential for human metabolism and fatty acid transport, are primarily obtained from the diet. Inadequate synthesis or intake can lead to serious metabolic disorders, which may result in fatal outcomes. Therefore, the accurate determination of carnitines in both food and biological samples is of high importance. However, these samples are inherently complex and require meticulous preparation procedures before determination. This step is critical for enhancing the sensitivity and precision of the detection process. Moreover, the selection of an appropriate detection method is crucial and must match the analytes' characteristics. For example, since carnitines lack chromophores for spectroscopic detection, they require derivatization to become spectroscopically visible. Among the various methods available for carnitine determination, chromatography and mass spectrometry are the most prominent, owing to their superior selectivity and sensitivity. Nonetheless, there seems to be a lack of comprehensive reviews on this subject. Consequently, this article aims to compile the latest advancements in analytical methodologies for carnitines over the past decade (2013–2023), with a particular emphasis on the crucial contributions of chromatography and mass spectrometry techniques. This review provides crucial insights for metabolic research, underpinning advances in understanding carnitine's metabolic roles. It aims to highlight current innovations in carnitine analysis and inspire future breakthroughs impacting nutrition, diagnostics, and therapy. [ABSTRACT FROM AUTHOR]

Urine is one of the biological matrices most used for detecting human contamination, as it is representative and easily obtained via noninvasive sampling. This study proposes a fast, accurate, and ecological method based on liquid–liquid microextraction with low-temperature partition (μLLE/LTP). It was validated to determine nine pesticides (lindane, alachlor, aldrin, chlorpyrifos, dieldrin, endrin, DDT, bifenthrin, and permethrin) in human urine, in association with gas chromatography coupled with mass spectrometry (GC–MS). The technique was optimized through a factorial design. The best conditions for the simultaneous extraction of the analytes comprised the addition of 600 µL of water and 600 µL of acetonitrile (extracting solvent) to a 500-µL urine sample, followed by vortexing for 60 s. By freezing the samples for 4 h, it was possible to extract the pesticides and perform the extract clean-up simultaneously. The parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy were used to appraise the performance of the method. Good values of selectivity and linearity (R2 > 0.990), LOQ (0.39–1.02 μg L−1), accuracy (88–119% recovery), and precision (%CV ≤ 15%) were obtained. The μLLE/LTP–GC–MS method was applied to authentic urine samples collected from volunteers in Southeast Brazil. [ABSTRACT FROM AUTHOR]

Hydroxyl polycyclic aromatic hydrocarbons are considered active mutagenic and carcinogenic substances and are found in extremely low levels (ng/g) in biological samples. As a result, their determination in urine and blood samples is challenging, and a sensitive and effective method for the analysis of trace hydroxyl polycyclic aromatic hydrocarbons in complex biological matrices is required. In this work, a novel macroporous in‐tube solid‐phase microextraction monolith was prepared via a thiol‐yne click reaction, and a highly efficient analytical method based on in‐tube solid‐phase microextraction coupled with UHPLC‐MS/MS was developed to determine hydroxyl polycyclic aromatic hydrocarbons with low detection limits of 0.137–11.0 ng/L in complex biological samples. Four hydroxyl polycyclic aromatic hydrocarbons, namely, 2‐hydroxyanthraquinone, 1‐hydroxypyrene, 1,8‐dihydroxyanthraquinone, and 6‐hydroxychrysene, were determined in the urine samples of smokers, non‐smokers, and whole blood samples of mice. Satisfactory recoveries were achieved in the range of 83.1–113% with relative standard deviations of 3.2–9.7%. It was found that implementation of the macroporous monolith gave a highly efficient approach for enriching trace hydroxyl polycyclic aromatic hydrocarbons in biological samples. [ABSTRACT FROM AUTHOR]

Context As a toxic traditional Chinese medicine for edoema, Euphorbia kansui S.L. Liou ex S.B. Ho (Euphorbiaceae) (EK) stir-fried with vinegar for detoxification was associated with alterations of gut microbiota. However, the evidence of correlation between short-chain fatty acids (SCFAs) and toxicity of EK has not been confirmed. Objective In order to study the biological basis of detoxification of EK stir-fried with vinegar (VEK), a rapid, sensitive and validated GC-MS method was developed to determine SCFAs in normal rat faeces after given EK and VEK. Materials and methods Sprague Dawley rats were orally administered 0.5% CMC-Na (control group), EK (EK-treated group) and VEK powder (VEK-treated group) at 680 mg/kg for six consecutive days (eight rats each group). Fresh faeces samples were promptly collected, derivatized and then analyzed by GC-MS. Results The ranges of LOD and LOQ were within 0.13–1.79 and 0.45–5.95 μg/mL, respectively. The RSD values of intra-day and inter-day precisions were less than 15%. Four SCFAs were generally stable under four storage conditions. The extraction recoveries were ranged from 53.5% to 97.3% with RSD values lower than 15%. The concentrations of four SCFAs in EK and VEK were decreased significantly compared with those not administered (EK-treated, p

Ion beam-induced heat damage in thermally low conductive specimens such as biological samples is gaining increased interest within the scientific community. This is partly due to the increased use of FIB-SEMs in biology as well as the development of complex materials, such as polymers, which need to be analyzed. The work presented here looks at the physics behind the ion beam-sample interactions and the effect of the incident ion energy (set by the acceleration voltage) on inducing increases in sample temperature and potential heat damage in thermally low conductive materials such as polymers and biological samples. The ion beam-induced heat for different ion beam currents at low acceleration voltages is calculated using Fourier's law of heat transfer, finite element simulations, and numerical modelling results and compared to experiments. The results indicate that with lower accelerator voltages, higher ion beam currents in the nanoampere range can be used to pattern or image soft material and non-resin-embedded biological samples with increased milling speed but reduced heat damage., (Copyright © 2024, Wolff et al.)

The present research dealt with using a carbon paste electrode (CPE) modified by gold nano-particles (AuNPs) graphene nano-sheets (GNs) and 4-hydroxy-2-(triphenylphosphonio) phenolate (HTP) in order to determine of cisplatin. The nano-composite exhibited excellent electrocatalytic activity for the determination of cisplatin by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. CV measurements were used to determine the kinetic parameters including electron transfer coefficient (α) and heterogeneous rate constant (k′) for cisplatin oxidation at the surface of modified electrode, which were 0.39 and (1.23 ± 0.17) × 10–3 cm s–1, respectively. At pH 7.0, cisplatin oxidation at the surface of modified electrode (HTP–AuNPs/GNs–CPE) was down at a potential of ~410 mV less than that of an unmodified electrode (CPE). According to DPV experiments, cisplatin oxidation ranged from 1.0 to 120.0 µM and limit of detection of 0.88 µM. The modified electrode showed acceptable function to detect cisplatin in biological samples by standard addition method. [ABSTRACT FROM AUTHOR]

A sensitive and selective LC-MS/MS method to quantify Lamivudine and Nevirapine in K3EDTA human plasma over the concentration range of 25.0240 to 3997.1740 ng/mL and 37.5080 to 5991.0460 ng/mL, respectively were developed and validated. Lamivudine and Nevirapine and its internal standard (Lamivudine 13C 15N2 and Nevirapine D5) were selectively extracted from 300 µL plasma by direct elution using solid phase extraction technique. Elution was achieved by reverse phase liquid chromatography on Hypurity C18 (100 mm × 4.6 mm, 5.0 µm) column was done. LLOQ of 25.0240 ng/mL and 37.5080 ng/mL were resolute for this technique for Lamivudine and Nevirapine respectively. Accuracy and precision values for Lamivudine were 99.55 & 1.50 and for Nevirapine the accuracy and precision values are 99.33 & 1.03%, respectively. [ABSTRACT FROM AUTHOR]