Analytical Response Research Articles

Identification of ketamine and norketamine in dried bloodstains on crime-scene surfaces

BackgroundToxicological analysis of dried bloodstains (DBS) provides critical information for reconstructing the sequence of events at a crime scene. Drugs have higher stability in DBS relative to liquid blood owing to the arrest of enzymatic reactions in dehydrated samples. However, literature on the identification of ketamine and its metabolites in DBS is limited and is mostly focussed on the analysis of bloodstains collected on paper cards. The present study has analysed the stability of ketamine and norketamine in DBS aged on common crime scene surfaces under various storage temperatures. Coloured linen fabric and glass slide, representing porous and non-porous surfaces, respectively, were stained with a defined volume of drug-fortified whole blood and stored at room temperature (20 °C), in the refrigerator (4 °C), and freezer (− 20 °C) for 1, 7, and 14 days. Analytes were solvent-extracted using a dichloromethane: hexane (1:3 v/v) mixture, followed by gas chromatography-mass spectrometry (GC–MS) analysis with ketamine-d4 as the internal standard.ResultsAt least 4.3 ng/mL and 8.7 ng/mL ketamine and norketamine, respectively, were detected in dried stains prepared from 5 to 50 µL whole blood corresponding to a concentration range of 10–100 ng/mL. The GC–MS method was linear in this range with a coefficient of determination, R2 > 0.99. Recovery of the analytes was comparable (~ 100–120%) between DBS porous and whole blood, whereas it was considerably lower (~ 50%) in DBS non-porous samples due to the incomplete transfer of the stains from the glass into the extraction solvent mixture. Analyte response in DBS showed a strong correlation with that in whole blood at four concentration levels (0.1–5 µg/mL). Mean precision values (% CV) for biological and technical replicates (n = 5) were 15.0 and 6.5, respectively, and within an acceptable range.ConclusionsThe developed method for the analysis of ketamine and norketamine in DBS is comparable to that in other biological matrices such as whole blood under short-term storage conditions. Lower temperatures are favourable for maintaining the integrity of the samples; however, the bloodstains must be completely dried before storing them in the refrigerator or freezer for short-term (1–7 days) to prevent hydrolytic degradation of drugs.Graphical

Current advances in the analysis of free RNA modified nucleosides by high performance liquid chromatography-tandem mass spectrometry

Post-transcriptional ribonucleic acid (RNA) modifications play crucial roles in regulating gene expression, with both eukaryotic and prokaryotic RNA exhibiting more than 170 distinct and ubiquitous modifications. RNA turnover generates numerous free nucleosides, including unmodified nucleosides and a variety of modified ones. Unlike unmodified nucleosides, modified nucleosides are not further degraded or used in the salvage-synthesis pathway owing to a lack of specific enzymes, which leads to the cytosolic accumulation or cellular efflux of modified nucleosides. These modified nucleosides can act as signaling molecules that regulate downstream pathways once transported to the extracellular space; alternatively, they are metabolized in the bloodstream and excreted in urine. Metabolized modified nucleosides are altered by cellular stress responses and mediate abnormal physiological states. Changes in the urinary and blood levels of modified nucleosides associated with cancer can serve as biomarkers for disease. Therefore, identifying and accurately quantifying nucleosides is vital for understanding RNA degradation and associated patterns of nucleoside metabolism. Such analyses are helpful when studying the biological functions and potential clinical applications of modified nucleosides. In this regard, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) offers significant advantages in terms of sensitivity, selectivity, and efficiency, and has been widely used to analyze DNA and RNA nucleosides/nucleotides and their analogues. Multiple MS detection patterns and quantification methods have been established to detect nucleosides in biological samples, including cultured cells, urine, blood, and tissue samples. However, the development of an accurate HPLC-MS/MS method faces several challenges. Firstly, the presence of a complex biological matrix that contains macromolecules, small molecules, and salts can interfere with analysis. Salts and co-eluting substances in the extraction solution often affect mass-spectrometric responses for target analytes. Secondly, various nucleosides are present in vastly different abundances, with contents varying by up to four orders of magnitude; hence, accurately quantifying multiple nucleosides in a single assay is challenging. Thirdly, N-glycosidic bonds are favorably cleaved in most nucleosides during MS to produce the same characteristic fragment ions, which are often accompanied by nucleobases. This tendency poses challenges for distinguishing structural isomers and mass-analogs of modified nucleosides by MS. Post-transcriptional chemical modifications include methylation, hydroxylation, sulfur/oxygen substitution, and side-chain additions. Developing a unified method for simultaneously screening modified nucleosides is difficult owing to biochemical diversity; consequently, there is a need for advanced HPLC-MS/MS method capable of accurately quantifying such nucleosides. This review summarizes the development and applications of LC-MS technologies for analyzing endogenous nucleosides, covering sample preparation, chromatographic-separation and mass-spectrometric-detection conditions, and the development of quantification methods. Additionally, we discuss applications aimed at detecting and quantifying RNA-derived modified nucleosides in biological samples. The applications of HPLC-MS/MS technology are highlighted, the regulation and function of free modified nucleosides are discussed, and the potential functions of modified nucleosides as disease biomarkers for clinical applications are introduced.

Optimizing Sustainable High-performance Green-concrete Characteristics with Minimum Cement Content: Experimental Program

With the increasing cement demand for concrete production, this study aims to optimize the compressive strength and rapid chloride permeability (RCP) of highperformance green concrete (HPGC) with minimum cement content using an experimental and analytical Response Surface Method (RSM). Waste palm oil fuel ash (POFA) was treated by heating and grinding processes to produce ultrafine POFA (UPOFA), which was employed by 0%, 30%, and 60% as a replacement binder with cement in HPGC production. Silica Fume (SF) was replaced by 0%, 10%, 15%, and 20% of the remaining mass of cement. The RSM with a central composite design (CCD) approach was utilized to optimize the mix design parameters. The experimental results showed that HPGC containing 30% UPOFA and 20% SF achieved superior compressive strength at ages of 28 days and 90 days. The combination of 60% UPOFA and 20% SF demonstrated the lowest permeability to chloride. The developed models had statistical significance and demonstrated satisfactory correlation values (R2) of 99.43 and 99.9; 99.46 and 99.67 for compressive strength and RCP at 28 days and 90 days, respectively. Thus, RSM could be an effective strategy for optimizing the mix design and reducing the harmful environment by minimizing waste volume and intensive energy for cement production, thereby harnessing concrete sustainability. Keywords: Concrete sustainability, Green concrete, RSM, UPOFA, Silica fume.

In situ developed NiCo2O4-Ti3C2Tx nanohybrid towards non-enzymatic electrochemical detection of glucose and hydrogen peroxide.

Owing to the adverse consequences of excess glucose (Glu) and hydrogen peroxide (H2O2) on humans, it is imperative to develop an electrochemical sensor for detection of these analytes with good selectivity and sensitivity. Herein, a nanohybrid comprising nickel cobaltite nanoparticles (NiCo2O4 NPs) embedded on conductive Ti3C2Tx nanosheets (NSs) has been prudently designed and employed for the electrochemical detection of Glu and H2O2. The developed nanohybrid has been systematically characterized using morphological and spectral techniques, and then immobilized on a glassy carbon electrode (GCE). Under optimized conditions, the developed NiCo2O4-Ti3C2Tx/GCE based electrochemical sensor has demonstrated an impressive analytical response towards Glu and H2O2 with good sensitivity and selectivity. The non-enzymatic sensor has demonstrated a broad linear range from 30 μM to 1.83 mM for Glu, and two linear ranges of 20-100 μM and 100 μM-2.01 mM for H2O2. The sensor has exhibited limits of detection (LOD) of 9 μM and 6 μM with sensitivities of 101.2 μA μM-1 cm-2 and 107.03 μA μM-1 cm-2, respectively, for Glu and H2O2 detection. The impressive analytical performance of the fabricated sensor in terms of linear range, LOD and sensitivity are ascribed to the (i) enhanced conductivity of Ti3C2Tx NSs, (ii) mediated electrocatalytic activity of NiCo2O4 NPs and (iii) large number of catalytically active sites on the NiCo2O4-Ti3C2Tx heterostructure. Notably, the NiCo2O4-Ti3C2Tx/GCE has demonstrated impressive stability and reproducibility, which is mainly due to the in situ uniform growth of NiCo2O4 NPs over Ti3C2Tx NSs.

Allosteric Fluorescent Detection of Saccharides and Biomolecules in Water from a Boronic Acid Functionalized Arene Ruthenium Assembly Hosting Fluorescent Dyes

A water-soluble arene ruthenium metalla-rectangle (MR1) functionalized with boronic acid groups was used to host various fluorescent dyes (fluorescein, eosin Y, and erythrosin B). These simple host–guest systems partially quench the natural fluorescence of the dyes, which can be regained in the presence of saccharides, phosphorylated molecules, and other analytes. The intensity of the regained fluorescence is directly linked to the nature of the analyte, and it shows some dose–response relationships with saccharides and phosphorylated molecules that are not compatible with a displacement assay, thus suggesting an allosteric mechanism. Interestingly, when fluorescein is trapped by the metalla-rectangle in the presence of D-fructose, half of the maximum fluorescence intensity is recovered at a fructose concentration of 17.2 ± 4.7 μM, while, for D-glucose, a concentration of 50.6 ± 2.5 μM is required for the same effect. Indeed, all combinations of analyte–host–dye (seven analytes, one host, three dyes) show a unique dose–response relationship in water at pH 8.0. However, in the presence of naphthalene and pyrene, fluorescein⸦MR1 shows a different behavior, acting as an indicator displacement assay with the full recovery of fluorescence. All data were analyzed by unsupervised machine learning technologies (PCA and cluster analysis), suggesting that such systems with multiple analyte–response behaviors are offering new perspectives for the development of highly sensitive, easily tunable, water-soluble, fluorescent-based sensing arrays for biomolecules and other analytes.

Quercetin Reduced and Stabilized Gold Nanoparticle/Al3+: A Rapid, Sensitive Optical Detection Nanoplatform for Fluoride Ion.

In this contribution, facile synthesis of gold nanoparticles (AuNPs) at ambient conditions is reported based on the use of the polyphenolic compound quercetin (QT) as the reducing and stabilizing agent at room temperature (RT). Under alkali-induced pH adjustment of QT solution and stirring conditions at RT, QT could quickly reduce gold salt (Au3+) into its nanoparticle form (Au0), resulting in the formation of a sparkling red color colloidal solution (AuNPs) with an absorption maximum at 520 nm. Further, Fourier transform infrared spectroscopy (FTIR) was employed to showcase the role of QT in the nanomaterial's synthesis process. The formed QT-AuNPs responded swiftly to Al3+ charging with color perturbation from red to grayish-purple, coupled with an absorption spectra red shift, owing to Al3+-induced aggregation of QT-AuNPs. However, when fluoride ion (F-) was pre-mixed with an optimized Al3+ concentration, reversed color changes from grayish-purple to red were observed with a blue shift in the absorption spectra. Simply put, F- formed a complex with Al3+, thus preventing Al3+-induced aggregation of QT-AuNPs. The analytical response A520/A650 was linear with F- concentration ranging from 25.0 to 250.0 µM and 250.0-600.0 µM, with a detection limit of 7.5 µM. The developed QT-AuNPs/Al3+ detection probe was selective to only F- charging, in comparison with other possible interfering anions. Real sample potentiality of the developed sensor was demonstrated on tap water samples, toothpaste, and fluoride-rich mouthwash, with reliable accuracy.

Sorbent-Based Sampling With Two-Stage Trapping/Desorption Coupled to Comprehensive Two-Dimensional Gas Chromatography and Mass Spectrometry for Terpenoids Profiling in Cannabis.

Cannabis inflorescences represent an important source of many high-value bioactive specialized metabolites, among which the family of terpenes or terpenoids that are the largest classes of natural products known. Besides their biological activities either alone or synergistic with other terpenoids and/or cannabinoids, they are responsible for their distinctive flavour. In this study, we exploited the separation power and identification capabilities of comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) for the profiling of terpenes and terpenoids in cannabis inflorescences. The dynamic headspace (DHS) used herein for the extraction was chosen for its sensitivity, portability, suitability, as well as its versatility of sampling various natural products, including plant raw materials and different plant parts. The enrichment method and the following desorption into the GC were developed and optimized on both standards and real samples considering different sorbent traps (i.e. Tenax-TA, Carbotrap T420, Carbotrap 202), and evaluating key performance values. Analyte coverage, recovery and response reproducibility were used for the evaluation of the best performing thermal desorption tube. Considering terpenoids profiling on cannabis inflorescences, satisfactory extraction performance was observed with both Tenax-TA and Carbotrap T420. However, Tenax-TA provided a wider analyte coverage beyond the class of terpenoids, thus can be better suited for non-targeted analysis. On the other hand, peak width, peak height, peak quality and resolution were considered for the optimization of the chromatographic process, and more specifically the injection process, demonstrating the benefit of a secondary trapping/desorption stage with a cryotrap. Finally, considering the final DHSE-TD-GC×GC-MS conditions, terpenes and terpenoids were profiled in real-world cannabis inflorescences, highlighting the differences among the chemovars.

A novel sonogel-Leucine electrochemical sensor for the detection of neuroblastoma biomarker in human urine and synthetic cerebrospinal fluid.

A new Sonogel-Carbon (SNGC) electrode modified with an amino acid (l-leucine; Leu) has been developed for the sensitive detection of homovanillic acid (HVA). Electrochemical properties of leucine-modified Sonogel-Carbon (SNGC-Leu) were characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Comprehensive characterization using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and powder X-ray diffraction (XRD) was conducted to investigate the structure of both SNGC-Leu and SNGC electrodes. The analytical performance of the SNGC-Leu sensor including the linear response range, repeatability, selectivity, and detection limit were examined. Differential pulse voltammetry (DPV) was employed to evaluate the analytical response in a linear concentration range of HVA from 0.5μM to 50μM, with a detection limit of 0.4 μΜ. Satisfactory reproducibility and repeatability (coefficient of variation (%RSD)<3.5%) were obtained. The SNGC-Leu sensor was successfully used to detect HVA in human urine and synthetic cerebrospinal fluid (CSF), exhibiting adequate recovery rates of 97.5-102% and 96.3-106%, respectively.

A simplified approach for simulating pollutant transport in small rivers with dead zones using convolution

Abstract In the paper an alternative method to solve the one-dimensional advective-diffusive equation describing the pollutants transport in river with dead zones is presented. Because very often transport in a small river can be treated as a 1D issue, then instead of numerical solution of the advection-diffusion equation an equivalent approach based on the convolution technique can be used. Consequently, for a given impulse response function the numerical calculations are required to compute a convolution only. The impulse response function is obtained as an analytical solution of the linear advection-diffusion equation for the Dirac delta function imposed as the boundary condition at the upstream end. Therefore, it represents the Gauss distribution and consequently, this approach is unreliable when the dead zones occur. To reproduce an asymmetric distribution of concentration along the channel axis an approximation of analytical impulse response function using the asymmetric Gumbel distribution is proposed. This approach valid for solution of the transport equation with constant coefficients is extended for piecewise constant coefficients. Convolution approach does not produce any numerical dissipation and dispersion errors typically generated by the methods based on the finite difference technique. Validation of the method using the results of field measurements confirmed its effectiveness.

A Self‐Powered and Self‐Absorbing Wireless Sensor Node for Smart Grid

The health monitoring of electricity transmission systems has been increasingly attracting the scientific community's attention, especially those power transmission towers built in remote and deserted areas. The smart grid provides a realistic solution to the health monitoring problem, but there is a problem that the energy supplies are still constrained by batteries. This article proposes a novel vibration energy harvester to address the power supply challenges of auxiliary equipment mounted on electricity towers or transmission lines. The proposed harvester not only harvests vibration energy when working but also attenuates the vibration amplitude of the transmission line. The structure of the device comprises three modules: a module for capturing vibration, a module for motion conversion, and a power management module. The analytical response under sinusoidal and random excitation is investigated, and the performance of energy harvesting and the effect on vibration is tested. The prototype achieves a maximum power of 183.96 mW when tested using the servo hydraulic mechanical testing and sensing system, and the wireless data transmission experiment proves the power generation ability of the prototype. The experimental results show that the acceleration of the transmission line decreases when the prototype is working.

Surface-Enhanced Raman Scattering-Based Multimodal Techniques: Advances and Perspectives.

Surface-enhanced Raman scattering (SERS) spectroscopy is a versatile molecular fingerprinting technique with rapid signal readout, high aqueous compatibility, and portability. To translate SERS for real-world applications, it is pertinent to overcome inherent challenges, including high sample variability and heterogeneity, matrix effects, and nonlinear SERS signal responses of different analytes in complex (bio)chemical matrices with numerous interfering species. In this perspective, we highlight emerging SERS-based multimodal techniques to address the key roadblocks to improving the sensitivity, specificity, and reliability of (bio)chemical detection, bioimaging, theragnosis, and theragnostic. SERS-based multimodal techniques can be broadly categorized into two categories: (1) complementary methods or systems that work together to achieve a common goal where each method compensates for the weaknesses of the other to culminate in a single enhanced outcome or (2) orthogonal techniques that are independent and provide separate but corroborating results simultaneously without interfering with each other. These multimodal techniques maximize information gained from a single experiment to achieve enhanced qualitative or quantitative analysis and broaden the range of detectable analytes from small molecules to tissues. Finally, we discuss emerging directions in multimodal platform design, instrument integration, and data analytics that aim to push the analytical limits of holistic detection.

New effectual configuration of bistable nonlinear energy sink

The study presents a new configuration of nonlinear energy sinks (NESs) which is adaptable to function as either stable or bistable NES. The proposed NES is based on the spring-loaded inverted pendulum (SLIP) in which a torsional stiffness element couples the SLIP to the linear oscillator (LO). The bistable configuration provides a critically stable position when the SLIP is vertically aligned with respect to the LO motion. At this critical stability position, the SLIP NES incorporates pre-stored potential energy which generates the bistability characteristics resembling that of a stiffness-based bistable NES. The equations of motion of the coupled LO with the SLIP NES are derived based on the Euler–Lagrange method in non-dimensional form. The parameters of the considered SLIP NESs are optimized to achieve an optimum energy absorption from the LO. The proposed B-SLIP NES is also applied to suppress seismic ground motion and forced torsional vibrations. The obtained numerical simulation and analytical response results verify the robustness of the B-SLIP NES in vibration suppression performance compared with the tuned mass damper and the cubic stiffness NES.

A rapid colorimetric sensor for the detection of mercury in environmental samples employing 2 aminobenzohydrazide schiff base functionalized silver nanoparticles

Mercury (Hg2+) is an extremely toxic and dangerous element for living organisms. Herein, a simple and selective sensor based on the Schiff base of 2-aminobenzohydrazide with triazole thiazole substituted vanillin (EAHT) functionalized silver nanoparticles (EAHT-AgNPs) is proposed for the detection of Hg2+ in environmental water samples. The chemical reduction method was employed to synthesize EAHT-AgNPs using sodium borohydride as the reducing agent. The synthesized nanoparticles were initially confirmed by UV-visible and FTIR spectroscopy, followed by analysis with a zeta sizer to determine their average size, surface charge and polydispersity index. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) were employed to determine the size and morphology of EAHT-AgNPs. Additionally, the functionalized particles exhibited stability at varying pH values, salinity concentrations and elevated temperature. The addition of Hg2+ altered the yellow color of EAHT-AgNPs to colorless, confirming the complex formation. The analytical response constructed as a decrease in absorbance versus concentration showed linearity (R2 = 0. 991) from 0.1 to 100 µM with a limit of detection of 0.04 µM (40 nM) and limit of quantification of 0.085 µM (85 nM). The sensor was successfully applied for the detection of Hg2+ ions in tap water. In conclusion, Schiff base of 2-aminobenzohydrozide with triazole thiazole substituted vanillin silver nanoparticle-based chemosensor is highly sensitive and selective for the detection of Hg2+ in water samples. The proposed sensor has been applied for mercury detection tap water, future research should explore its applications in more complex samples like industrial wastewater and marine environments. Further, studies may focus on the integrating of the approach into the portable devices such as smartphone for on-site detection of mercury.

Graphene quantum dots modified electrodes as electrochemical sensing tool towards the detection of codeine in biological fluids and soft drinks.

An electroanalytical method based on disposable screen-printed carbon electrodes modified with non-toxic carbonaceous nanodots is proposed as a reliable and effective device for codeine determination in biological fluids and soft drinks. Graphene quantum dots (GQDs), carbon quantum dots (CQDs) and carbon nanodots (CNDs) were evaluated as electrode modifiers for the determinationof the drug. The electroactive areas of the modified electrodes were assessed by cyclic voltammetry using potassium ferricyanide. Results demonstrated that GQDs provided the best analytical response for codeine, displaying an intense and well-defined anodic wave approximately 0.9V vs reference electrode. The method exhibits an acceptable linear dynamic range, low limits of detection and quantification (0.21 and 0.73µM, respectively), and satisfactory precision (below 3.9% expressed as relative standard deviation (RSD)) in saliva. Only the analysis of biofluids requires a simple extraction protocol. The feasibility and applicability of this novel approach were assessed by determining codeine in different matrices, with recoveries ranging from 69 to 112%. This cost-effective, simple, easily miniaturised and portable method was applied not only to biofluids but also for the direct detection of codeine in soft drinks combined with a codeine-enriched syrup, a medication that is being used to adulterate beverages, particularly at specific events (drinking and nightclub parties). There is no need forany sample treatment, demonstrating its versatility in analysing beverages for potential adulteration as well.

Laser-induced graphene gas sensors for environmental monitoring.

Artemesia tridentata is a foundational plant taxon in western North America and an important medicinal plant threatened by climate change. Low-cost fabrication of sensors is critical for developing large-area sensor networks for understanding and monitoring a range of environmental conditions. However, the availability of materials and manufacturing processes is still in the early stages, limiting the capacity to develop cost-effective sensors at a large scale. In this study, we demonstrate the fabrication of low-cost flexible sensors using laser-induced graphene (LIG); a graphitic material synthesized using a 450-nm wavelength bench top laser patterned onto polyimide substrates. We demonstrate the effect of the intensity and focus of the incident beam on the morphology and electrical properties of the synthesized material. Raman analyses of the synthesized LIG show a defect-rich graphene with a crystallite size in the tens of nanometers. This shows that the high level of disorder within the LIG structure, along with the porous nature of the material provide a good surface for gas adsorption. The initial characterization of the material has shown an analyte response represented by a change in resistance of up to 5% in the presence of volatile organic compounds (VOCs) that are emitted and detected by Artemisia species. Bend testing up to 100 cycles provides evidence that these sensors will remain resilient when deployed across the landscapes to assess VOC signaling in plant communities. The versatile low-cost laser writing technique highlights the promise of low-cost and scalable fabrication of LIG sensors for gas sensor monitoring.

Flexible Piezoelectric Nanocolumnar Composite Films as Flat-Panel Loudspeakers: Application and Modeling.

Highly anisotropic piezoelectric composites promise to progress electroacoustic devices as a class by combining the advantages of both piezoceramics and polymers. Fundamentally, piezoelectric loudspeakers employ the converse piezoelectric effect to convert electrical to mechanical energy. Quasi-1-3 piezoceramic/polymer composites enable flat-panel loudspeakers that are tunable in elastic modulus, with opportunities for mechanical flexibility, optical transparency, and large-area coverage. Their processing route enables relatively flexible design parameters, such as the particle loading, polymer-matrix modulus, film thickness, film size, and electrode-material stiffness. Alternative processing routes of electric field (E-field) aligned-piezoelectric composites are demonstrated, including using the relaxor ferroelectric lead magnesium niobate-lead titanate (PMN-PT) to enhance the acoustic performance and photocurable resins to accelerate the materials processing. Material properties critical for dielectrophoresis are characterized, and loudspeakers were fabricated based on the optimal processing conditions. Subsequently, electroacoustic characterization explores the effect of loudspeaker size, substrate stiffness, the microphone distance, the piezoceramic material, and the matrix modulus. Finally, finite-element (FE) modeling of the electromechanical behavior validates the natural frequencies and modes shapes of the loudspeakers via the analytical solution and frequency response to electrical and mechanical excitation. Good correspondence between the predicted electroacoustic performance and experimentally validated model is observed.

Catalytic competence of gold clusters decorated yellow 2 G polymer composite film for voltammetric sensing of dopamine and nicotine in biological fluids

A novel, simple, cost-effective, easy-to-prepare, and timesaving electrochemical sensor based on gold clusters decorated yellow 2 G polymer composite film was fabricated and comprehensively characterized for the determination of dopamine and nicotine in real samples. When gold clusters were modified on the yellow 2 G polymer film, a signal increase of 204 % for dopamine and 526 % for nicotine was obtained compared to the activated bare pencil graphite electrode. The signals at 90 mV for dopamine and 780 mV for nicotine were utilized as analytical responses. The fabricated platform serves noteworthy detection sensitivity values of 79.02μA.μM−1.cm−2 and 14.61μA.μM−1.cm−2 with a notable limit of detection values of 58.8 nM and 7.2 nM for dopamine and nicotine, respectively. The electrochemical method has linear ranges of 0.075–5 µM and 6–10 µM for dopamine alone, 0.01–10 µM and 12–25 µM for nicotine alone, 0.01–10 µM and 12–50 µM for nicotine in the presence of dopamine, 0.2–10 µM and 12–60 µM for dopamine in the presence of nicotine, and 0.4–2, 2–10 and 12–90 µM for dopamine and 0.2–8, 10–20 and 25–90 µM for nicotine at the increasing amounts of each substance. Moving forward, the developed method exhibits splendid accuracy and selectivity for determining dopamine and nicotine in biological samples of human saliva, serum, and urine.

Prompting Responses through Linguistic Cues: A Comparison of User and Chatbot Support for Consumers' Questions

ABSTRACTWhen interacting with chatbots, questioning is the starting point of the conversations. A well‐phrased question can elicit desired responses and enhance information‐seeking efficiency. Specifically, consumers can use various linguistic cues (e.g., emotional expressiveness) to phrase questions and shape responses. However, research on how to effectively phrase questions for chatbots was limited. This study focuses on consumers' questions for chatbots, examining how various linguistic cues (e.g., emotional expressiveness) influence responses. Further, it compares responses generated by community users and chatbots. Preliminary results showed that askers' self‐disclosure attracted emotional support from chatbots. Chatbots demonstrated higher expertise in responses to high‐specificity questions and produced more analytical and unified responses. In contrast, user‐generated responses were perceived with higher authenticity. This research underscores the role of question cues prompting chatbot‐generated responses and illustrates the strengths and limits of chatbot‐generated responses. Theoretical and practical implications are discussed in the final section.

Validation of GF-AAS Method for the Determination of Aluminium Content in Human Albumin Finished Product

Background: Purified human albumin fractionated from plasma has a complex matrix that imposes a lot of interference in quality control testing, particularly for impurities at trace level. In this study, a simple approach has been studied and validated for the quantification of aluminium content using Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). As per international guidelines, the linearity, accuracy, precision, specificity, limit of detection, and quantification have been assessed. Results: The linearity of the analyte response was evaluated over the range of concentrations from 5μg/L to 45 μg/L, and the correlation coefficient obtained was greater than 0.99. The mean recovery obtained for the accuracy ranged from 102.29% to 106.81% at three concentration levels. The specificity/selectivity evaluated for possible interference from other metal ions and relative standard deviation for the high and low content was 10.24% and 6.50%, respectively, which was statistically verified and not significant. Method precision was evaluated for repeatability and intermediate precision, and the relative standard deviation obtained was 1.83% and 4.61%, respectively. The limit of detection and quantification obtained was 1.30 μg/L and 4.10 μg/L, respectively. Conclusion: Results obtained for the method performance show the suitability of the method for aluminium estimation in human albumin samples and should be used to control the limit of aluminium in human albumin blood products.

Data Lakehouse: A survey and experimental study

Efficient big data management is a dire necessity to manage the exponential growth in data generated by digital information systems to produce usable knowledge. Structured databases, data lakes, and warehouses have each provided a solution with varying degrees of success. However, a new and superior solution, the data Lakehouse, has emerged to extract actionable insights from unstructured data ingested from distributed sources. By combining the strengths of data warehouses and data lakes, the data Lakehouse can process and merge data quickly while ingesting and storing high-speed unstructured data with post-storage transformation and analytics capabilities. The Lakehouse architecture offers the necessary features for optimal functionality and has gained significant attention in the big data management research community. In this paper, we compare data lake, warehouse, and lakehouse systems, highlight their strengths and shortcomings, identify the desired features to handle the evolving challenges in big data management and analysis and propose an advanced data Lakehouse architecture. We also demonstrate the performance of three state-of-the-art data management systems namely HDFS data lake, Hive data warehouse, and Delta lakehouse in managing data for analytical query responses through an experimental study.