Direct Extraction Research Articles

Review of methods for lithium extraction from geothermal brines

Lithium, a highly reactive and valuable metal, is essential for the clean energy transition, powering electronic devices, electric cars, and energy storage systems. With demand for lithium surging, environmentally responsible and economically viable extraction methods are crucial. Traditional sources include brines and mineral clays, but lithium-ion batteries have become a significant secondary source due to their high consumption of lithium. This review explores various extraction methods from geothermal brines, focusing on conventional techniques like solar evaporation, precipitation, and solvent extraction, highlighting their efficiency and limitations. Advanced electrochemical methods are also discussed, including the use of electrochemical ion pumping and electrodialysis, showcasing their potential for high-purity lithium recovery. Direct Lithium Extraction (DLE) technology, which offers over 90% recovery and reduces impurities by over 99%, is identified as a promising approach. The review underscores the need for large-scale field experiments and the development of new lithium sources to meet growing demand.

Lipoprotein(a) and atherosclerotic cardiovascular disease in a Brazilian tertiary hospital population

Abstract Background/Introduction Elevated levels of lipoprotein(a) [Lp(a)] are a strong risk marker of atherosclerotic cardiovascular disease (ASCVD), including myocardial infarction (MI), ischemic stroke, and peripheral arterial disease, as well as of aortic valve calcification and stenosis. However, few studies have assessed the prevalence of high Lp(a) levels in patients followed at a tertiary hospital specialized in cardiovascular diseases (CVD). In addition, there is scant information about Lp(a) concentrations in Brazilian individuals. Purpose The aim of the study was to describe the demographic characteristics and comorbidities of patients with at least one measure of Lp(a) at a tertiary treatment center for CVD in our city – Brazil. Methods Patients treated at a heart institute had their data extracted between the years 1999 and 2021. Data were obtained through direct electronic extraction of patients' medical records. The patients were categorized according to different Lp(a) cutoff levels (> 50 and < 70, > 70 and < 90, and > 90 mg/dL) and by quartiles. Results Of 4,970 unique patients included in the study, the mean age at baseline was 59.9 years (SD ± 14.5), 2,634 (53%) were male, and the median Lp(a) was 23.2 mg/dL (interquartile range 8.9 - 56.8 mg/dL). In the whole cohort, 460 (9.3%) had Lp(a) > 50 and < 70, 344 (6.9%) > 70 and < 90, 612 (12.3%) > 90 mg/dl and 138 (2.8%) > 150 mg/dL. Established ASCVD was reported in 1,223 (24%) of the individuals, with a progressively higher prevalence across the Lp(a) categories above (31.2%, 33.8%, 34.2%, respectively) (table 1). Moreover, the Lp(a) median (interquartile range) in mg/dL was significantly higher in those with baseline history of ASCVD (31.4 [10.8-71.2] vs 21.2 [8.3-52]), MI (27.8 [10.6-65.9] vs 22.3 [8.5-54.7]) and stroke (24.9 [10-69.5] vs 23.1 [8.9-56.5]), all p < 0.05 (table 2). Lp(a) was also significantly higher among those with LDL-C ≥ 100 mg/dL relative to LDL-C < 100 mg/dl (25.5[9.5-63.2] vs 21.4[8.4 vs 52.2] p < 0.05). Conclusions In this cohort of patients followed at a tertiary center specialized in CVD, approximately a third had Lp(a) levels above 50 mg/dL, a cutoff robustly associated with ASCVD. This finding likely represents an important source of cardiovascular residual risk, particularly in those with established ASCVD, exposing the need of further therapies.

Comprehensive Treatment of Impacted Teeth with Comprehensive Oral Clinical Diagnosis and Treatment Thinking

Impacted teeth are a common disease in oral surgery, which can be caused by systemic factors and local factors, and the incidence of different genders, races and tooth positions is different. The clinical manifestation of impacted teeth is the absence of permanent teeth in normal position. Cone beam CT can accurately diagnose and locate impacted teeth. At present, surgical fenestration or direct extraction are often used to treat impacted teeth, but the treatment effect and prognosis are not ideal enough. In the process of oral clinical diagnosis and treatment, doctors began to adopt comprehensive diagnosis and treatment thinking to solve problems, and the key to improve the success rate of oral disease treatment is to make a clear diagnosis, reasonably evaluate the difficulty of treatment and adopt appropriate correction methods. This paper summarizes the research status of impacted teeth in recent years, focusing on the multidisciplinary comprehensive treatment of impacted teeth, in order to improve the clinical comprehensive diagnosis and treatment thinking of dentists and provide reference for accurate treatment of impacted teeth and reduction of complications in the treatment process.

Molecular Insights of Separation of Lanthanide Metals from Aqueous Waste by Using Directional Solvent Extraction

Molecular Insights of Separation of Lanthanide Metals from Aqueous Waste by Using Directional Solvent Extraction

Review of Lithium as a Strategic Resource for Electric Vehicle Battery Production: Availability, Extraction, and Future Prospects

This article presents a comprehensive review of lithium as a strategic resource, specifically in the production of batteries for electric vehicles. This study examines global lithium reserves, extraction sources, purification processes, and emerging technologies such as direct lithium extraction methods. This paper also explores the environmental and social impacts of lithium extraction, emphasizing the need for sustainable and ethical practices within the supply chain. As electric vehicles are projected to account for over 60% of new car sales by 2030, the demand for high-performance batteries will persist, with lithium playing a key role in this transition, even with the development of alternatives to lithium-ion batteries, such as sodium and ammonium-based technologies. However, there is an urgent need for technological advancements to reduce the environmental impact of lithium production and lithium-ion battery manufacturing. Additionally, ensuring the safety of LiBs during both use and recycling stages is critical to sustainable EV adoption. This study concludes that advancements in battery recycling and the development of new technologies are essential to improving safety, reducing costs, and minimizing environmental impacts, thereby securing a sustainable lithium supply and supporting the future of electric mobility.

Multi-year comparison of VITEK MS performance for identification of rarely encountered pathogenic Gram-negative organisms (GNOs) in a large integrated Canadian healthcare region.

This multi-year study (2014-2019) compared identification of rare and unusual Gram-negative organisms (GNOs) by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (VITEK MS, bioMérieux, Laval Que.) to 16S rRNA gene sequencing (16S) according to our laboratories routine workflow; 16S is done if initial MALDI-TOF MS gave discordant, wrong, or no results. GNB isolates were first analyzed by standard phenotypic methods and MALDI-TOF MS using direct deposit-full formic acid extraction; proteomics was repeated if no result occurred. Medically approved 16S analyses were done using fast protocols. Isolate sequences were analyzed using the Integrated Database Network System (IDNS3) bacterial database (SmartGene, Lausanne, Switzerland). Three hundred thirty-one GNOs including 251 (76%) aerobic Gram-negative bacilli (GNB), 63 (19%) fastidious Gram-negative coccobacilli (fGNCBs), and 17 (5%) Campylobacterales (CAMPB) isolates were recovered from 304 specimens; >1 isolate was recovered from 19 (6%). GNOs were mainly recovered from blood cultures (31.6%) and lower respiratory specimens (43%) (one-half were isolated from cystic fibrosis patients). Accurate genus vs species identities were obtained for 67.7% and 32.5% aerobic GNBs, 73% and 60% fGNCBs, and 23.5% CAMPB (with no discrepant species), respectively. Wrong or no results were obtained for 81 (32.3%) aerobic GNBs, 17 (27%) fGNCBs, and 13 (72.2%) CAMPB. No results or misidentifications occurred for 33% of aerobic GNBs, 26% of fGNCBs, and 76.5% of CAMPB due to absence of species in the instrument's database. VITEK MS performance remained stable for aerobic GNBs and fGNCBs but improved for CAMPB with addition of Campylobacter rectus and Campylobacter curvus to the database. 16S remains important for identification of GNOs when proteomics fails.IMPORTANCEMatrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has transformed the identification of commonly encountered Gram-negative organisms (GNOs) in the clinical laboratory, but rare and unusual organisms continue to challenge the technology. This study verified performance of VITEK MS for identification of a broad range of rare and unusual clinical GNO isolates by our large reference laboratory workflow over a multi-year period. Although most GNOs were accurately identified by MALDI-TOF MS, a small number of clinical isolates (~1%-6%) required 16S sequencing for identification depending on the GNO category. Approximately one-third of aerobic Gram-negative bacilli (GNBs) and two-thirds of Campylobacterales could not be accurately identified by proteomics due to lack of an organism in the instrument's database. MALDI-TOF MS databases should be continuously updated and validated, and laboratories should have a workflow for identification of unusual or rarely encountered aerobic, fastidious, and Campylobacterales GNOs that includes 16S rRNA gene sequencing whenever proteomics cannot give a definitive identification.

A Comprehensive and Repeatable Contrast-Enhanced Ultrasound Quantification Approach for Clinical Evaluations of Tumor Blood Flow.

The aim of this study is to define a comprehensive and repeatable contrast-enhanced ultrasound (CEUS) imaging protocol and analysis method to quantitatively assess lesional blood flow. Easily repeatable CEUS evaluations are essential for longitudinal treatment monitoring. The quantification method described here aims to provide a structure for future clinical studies. This retrospective analysis study included liver CEUS studies in 80 patients, 40 of which contained lesions (primarily hepatocellular carcinoma, n = 28). Each patient was given at least 2 injections of a microbubble contrast agent, and 60-second continuous loops were acquired for each injection to enable evaluation of repeatability. For each bolus injection, 1.2 mL of contrast was delivered, whereas continuous, stationary scanning was performed. Automated respiratory gating and motion compensation algorithms dealt with breathing motion. Similar in size regions of interest were drawn around the lesion and liver parenchyma, and time-intensity curves (TICs) with linearized image data were generated. Four bolus transit parameters, rise time (RT), mean transit time (MTT), peak intensity (PI), and area under the curve (AUC), were extracted either directly from the actual TIC data or from a lognormal distribution curve fitted to the TIC. Interinjection repeatability for each parameter was evaluated with coefficient of variation. A 95% confidence interval was calculated for all fitted lognormal distribution curve coefficient of determination (R2) values, which serves as a data quality metric. One-sample t tests were performed between values obtained from injection pairs and between the fitted lognormal distribution curve and direct extraction from the TIC calculation methods to establish there were no significant differences between injections and measurement precision, respectively. Average interinjection coefficient of variation with both the fitted curve and direct calculation of RT and MTT was less than 21%, whereas PI and AUC were less than 40% for lesion and parenchyma regions of interest. The 95% confidence interval for the R2 value of all fitted lognormal curves was [0.95, 0.96]. The 1-sample t test for interinjection value difference showed no significant differences, indicating there was no relationship between the order of the repeated bolus injections and the resulting parameters. The 1-sample t test between the values from the fitted lognormal distribution curve and the direct extraction from the TIC calculation found no statistically significant differences (α = 0.05) for all perfusion-related parameters except lesion and parenchyma PI and lesion MTT. The scanning protocol and analysis method outlined and validated in this study provide easily repeatable quantitative evaluations of lesional blood flow with bolus transit parameters in CEUS data that were not available before. With vital features such as probe stabilization ideally performed with an articulated arm and an automated respiratory gating algorithm, we were able to achieve interinjection repeatability of blood flow parameters that are comparable or surpass levels currently established for clinical 2D CEUS scans. Similar values and interinjection repeatability were achieved between calculations from a fitted curve or directly from the data. This demonstrated not only the strength of the protocol to generate TICs with minimal noise, but also suggests that curve fitting might be avoided for a more standardized approach. Utilizing the imaging protocol and analysis method defined in this study, we aim for this methodology to potentially assist clinicians to assess true perfusion changes for treatment monitoring with CEUS in longitudinal studies.

3D Building Modelling from ALS Point Clouds by Delaunay Triangulation and Graph Theories

Abstract. As an important task in 3D building reconstruction, 3D roof reconstruction attracts increasing attention. Existing methods have the issue of additional errors caused by multi-step processes, resulting in relatively high uncertainty and potentially affecting the reconstruction accuracy. Deep learning-based methods to achieve the direct extraction of roof vertices and edges for reconstructing 3D roof structures tackle the issue of additional errors while leading to another problem: the reliance on large labeled datasets for training. In this study, a fully rule-based method is proposed to achieve automatic 3D roof reconstruction. Roof vertices with their edges parallel to the x-y plane are first extracted from the point clouds, and subsequently, the left roof edges connecting vertices are inferred by using Delaunay triangulation. Finally, the 3D roof structure is reconstructed by using graph analysis based on the information of roof vertices and edges. This method simplifies the process of 3D roof reconstruction, and the experiment results demonstrate that the proposed method can effectively reconstruct 3D roof structures from point clouds.

Unlocking sustainable lithium: A comparative life cycle assessment of innovative extraction methods from brine

The surging demand for lithium, driven by the widespread adoption of electric vehicles and renewable energy storage systems, underscores the urgent need to develop sustainable lithium extraction methods. This study presents a comprehensive Life Cycle Assessment Using the TRACI method to evaluate and compare the environmental impacts of solvent extraction, adsorption, nanofiltration, and membrane electrolysis as direct lithium extraction methods for recovering lithium from brine to produce lithium carbonate. In terms of global warming, the carbon dioxide emission for each process was determined as follows: solvent extraction emits 52.7 kg CO2eq/kg of lithium carbonate, adsorption emits 47.9 CO2eq/kg of lithium carbonate, nanofiltration emits 17.7 kg CO2eq/kg of lithium carbonate, and membrane electrolysis emits 80.57 kg CO2eq/kg of lithium carbonate. As a result, the nanofiltration process emerges as the most environmentally friendly method, offering a promising solution to the environmental challenges of lithium extraction. In contrast, the membrane electrolysis process has the highest environmental impact.

Artificial intelligence for brain disease diagnosis using electroencephalogram signals.

Brain signals refer to electrical signals or metabolic changes that occur as a consequence of brain cell activity. Among the various non-invasive measurement methods, electroencephalogram (EEG) stands out as a widely employed technique, providing valuable insights into brain patterns. The deviations observed in EEG reading serve as indicators of abnormal brain activity, which is associated with neurological diseases. Brain‒computer interface (BCI) systems enable the direct extraction and transmission of information from the human brain, facilitating interaction with external devices. Notably, the emergence of artificial intelligence (AI) has had a profound impact on the enhancement of precision and accuracy in BCI technology, thereby broadening the scope of research in this field. AI techniques, encompassing machine learning (ML) and deep learning (DL) models, have demonstrated remarkable success in classifying and predicting various brain diseases. This comprehensive review investigates the application of AI in EEG-based brain disease diagnosis, highlighting advancements in AI algorithms.

Room-Temperature Single-Phase Synthesis of Semiconducting Metal-Covalent Organic Frameworks With Microenvironment-Tuned Photocatalytic Efficiency.

In order to improve the solubility of metallated monomers and product crystallinity, metal-covalent organic frameworks (MCOFs) are commonly prepared via high-temperature sol-vothermal synthesis. However, it hampers the direct extraction of crystallization evolution information. Exploring facile room-temperature strategies for both synthesizing MCOFs and exploiting the crystallinity mechanism is extremely desired. Herein, by a novel single-phase synthetic strategy, three MCOFs with different microstructure is rapidly prepared based on the Schiff base reaction between planarity-tunable C3v monomers and metallated monomers at room temperature. Based on detailed time-dependent experiments and theoretical calculations, it is found that there is a planarity-tuned and competitive growth relationship between disordered structures and crystal nucleus for the first time. The high planarity of monomers boosts the formation of crystal nucleus and rapid growth, suppressing the forming of amorphous structures. In addition, the microenvironment effect on selective photocatalytic coupling of benzylamine (BA) is investigated. The strong donor-acceptor (D-A) MCOF exhibits efficient photocatalytic activity with a high conversion rate of 99% and high selectivity of 99% in 5h under the 520nm light irradiation. This work opens a new pathway to scalable and efficient synthesis of highly crystalline MCOFs.

Direct extraction of optical constants of organic semiconductors in ultrastrongly coupled microcavities and their application in antireflection design for polariton devices

The strongly bound Frenkel excitons in organic semiconductors enable strong or even ultrastrong exciton-photon coupling in room-temperature cavities, with the resulting polariton states typically resolved through reflectance measurements. This paper demonstrates that the distinct features of exciton and polariton modes in the reflectance spectra of strongly/ultrastrongly coupled organic microcavities can be effectively utilized to extract the optical constants and physical thickness of the embedded organic semiconductor. We investigate metal-clad microcavities based on two prototype conjugated polymers, poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), both exhibiting ultrastrong coupling characteristics. The (n,k) spectra and thickness of these polymer films are determined by fitting the normal incidence reflectance spectra of organic microcavities, using Kramers-Kronig transformation and transfer-matrix calculations with varying optical and thickness parameters. We also examine the individual effects of the main fitting parameters on the spectrum, establishing a close correlation with the underlying polariton properties. Moreover, we analyze the optical admittance at exciton and polariton modes to understand reflectance variations with different parameters, which facilitates precise control of optical properties at specific modes through cavity design. Finally, using the extracted optical constants of MDMO-PPV and P3HT, we propose optimized microcavity designs that exhibit antireflection at the lower polariton mode for potential luminescence and photodetection device applications.

Quince (Cydonia oblonga Mill.) Waste By-Product Characterization as a Potential Functional Ingredient

Currently, the production of waste in the food industry is increasing, which is a serious problem. However, most of these residues, especially those derived from fruits and vegetables, have great unknown properties that are not used. The main objective of this article is the analysis and characterization of the waste from quince after its processing to observe its properties and its potential use in different industries as a functional ingredient, thus favoring the circular economy and sustainability. Quince by-product nutritional parameters such as proteins, fibers, sugars, vitamins, and minerals were analyzed. Also, the antioxidant capacity was measured by various methods: 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH), antioxidant capacity in Trolox equivalent antioxidant capacity (TEAC/ABTS), and total polyphenol content (TPC). Finally, the antimicrobial capacity against different postharvest-pathogenic fungi was measured in direct sample and extract. The nutritional results showed a nutritional profile rich in soluble and insoluble fiber, potassium, calcium, and magnesium, and low in fat. The antioxidant results from the extract showed significant levels of phenols and higher antioxidant capacity from the extracted sample. No positive results were found in the antimicrobial capacity study. Quince by-products could be a potential ingredient in the industry due to their nutritional composition and antioxidant content.

B-248 Enhanced Detection of of Hemoglobin Variants in Clinical Research using Dried Blood Spot and HRAM MS

Abstract Background Hemoglobinopathies are one of the most prevalent genetic disorders, with more than 330,000 affected births occurring annually. Common techniques used in Hb analysis are electrophoretic and chromatographic assays. However, there are challenges to differentiate isomers (i.e., between Hb C and Hb E), very similar masses, or new variants due to their lack of resolution. Mass spectrometry (MS) gained popularity in clinical research because of its robustness and versatility in analyzing a wide range of samples and analytes from small molecules to proteins. Here, we present the top-down analysis for enhanced detection of various hemoglobin variants using Orbitrap Exploris for clinical research. Methods Proteins were directly extracted from dried blood spots (DBS) and analyzed by Thermo Scientific™ Orbitrap Exploris™ 240 with BioPharma Option coupled to Vanquish HPLC system. A 3.2 mm disc was punched from the DBS cards to 96 well plate and 50 uL water was added to re-hydrate. For protein precipitation, 150 uL acetonitrile was added and incubated at -20 ⁰C for 15 minutes. After micro-centrifugation, 160 uL of supernatant was removed and 70 uL water was added to resuspend. For LC-MS analysis, 10 uL of supernatant was diluted 8 times with mobile phase A and transferred to another 96-well plate. LC separation was performed on MAbPac RP column 4 um, 1 x 100 mm, and data-dependent acquisition mode was operated. Results With direct protein extraction from DBS, the entire sample preparation time is less than 1 hour. The MAbPac column showed its capability of separating between different chains with minor overlap between normal beta and HbS beta chains. Data processing was performed by ProSightPD, resulting in ∼45% sequence coverage for both normal Hb and HbS beta chains. The mass difference between normal beta and Hb S beta chains is about 30 Da, which results in about 1.6 m/z difference at a charge state of 19. This mass difference can often be hindered by other proteins or interferences from the matrix if the mass analyzer doesn’t have sufficient resolving power. Here we successfully applied Orbitrap resolution at 120,000 to isolate these similar masses for accurate variants or subunits identification including normal alpha, normal beta, Hb S, and delta chains. The confirmation of the delta chain can be beneficial since its abundance is usually less than 0.5% in adults, which shows potential for detecting low abundant variants using this method. Also, the calibration curve was generated to demonstrate the method's feasibility which is not a typical quantitation method for hemoglobinopathies. For quantitation, three most abundant m/z values from 2 charge states were added to TraceFinder for peak area extraction and normal Hb beta chain was used as an alternative internal standard for data processing. The 3-day inter/intraday analysis generated great reproducibility with CV < 10% and LOQ was determined to be 2.5 mg/mL with R2 values >0.994. Conclusions Successful demonstration of a single-step protein extraction directly from DBS and top-down analysis of Hb variant for clinical research.

Reactivity of a plagioclase concentrate from the South African Bushveld Igneous Complex via extractive acid leaching vs. extractive roasting-leaching processes

This study compared the reactivity of a plagioclase concentrate subjected to two processes: (1) direct acid leaching and (2) thermochemical treatment with ammonium sulfate followed by leaching. The sample was prepared from coarse-grained pyroxenite rock retrieved from the Bushveld Igneous Complex, South Africa. It contained 78% plagioclase (labradorite), 9% orthopyroxene (enstatite) and 13% quartz. The elements contained in the concentrate were categorized into three groups based on their susceptibility to direct acid extraction after 6 h of leaching. Group 1 consisted of the highly reactive main elements of plagioclase (Al, Ca and Na, with extraction efficiencies of 95%, 89% and 81%, respectively). Group 2 included elements predominantly present in enstatite (Mg and Fe with extraction efficiencies of 41% and 55%, respectively). Group 3 was composed of slowly extractable Si (25%) from mostly plagioclase. Increasing the duration of direct acid leaching to 24 h had no effect on the extraction of Group 1 elements, whereas the extraction of Mg and Fe (Group 2) increased to >60%, and that of Si (Group 3) increased from 25 to 80%. The latter correlated with the nearly complete disappearance of the plagioclase blueprint in the XRD pattern of the residues generated after 24 h of leaching. In contrast, plagioclase had limited reactivity with ammonium sulfate during thermochemical treatment. Direct acid leaching of plagioclase-rich tailings can therefore generate leachates to be used as precursors for the preparation of value-added products, such as silica nanoparticles via a sol–gel route and calcium aluminate nanoparticles via solution combustion.

Bipolar Membrane Capacitive Deionization for the Selective Capture of Lithium Ions from Brines and Conversion to Lithium Hydroxide

Meeting the increasing demand for lithium in vehicle electrification and renewable energy storage requires innovations in lithium-ion (Li+) separations. Traditional solar evaporation methods for lithium recovery are slow and consume tremendous volumes of water and secondary chemicals (acids and bases). This study introduces a bipolar membrane capacitive deionization (BPM-CDI) unit for direct lithium extraction and LiOH production without the external addition of acids and bases. Utilizing de-lithiated lithium-iron-phosphate (LFP) coated carbon cloth electrodes, the BPM-CDI unit demonstrates selective Li+ capture over competing ions. Molecular dynamics simulations and H-cell experiments elucidate pH inversion mechanisms during Li+ release, yielding LiOH. The BPM-CDI platform efficiently removes Li+ from synthetic brines featuring 8x higher Mg2+ concentrations (200 ppm Mg2+) and 26x higher Na+ concentrations (682 ppm Na+), achieving a LiOH concentration of 124 ppm (36 ppm Li+) after 8 cycles of recirculation. Post-mortem analysis confirms electrode integrity and stability. BPM-CDI integrated with selective electrodes is a promising electrochemical separation-reactor platform for lithium recovery while producing LiOH.

Validation of Analytical Method for Vitamin A in Bioadhesive Ocular Cationic Nanoemulsion Loaded into Thermosensitive Gel Using RP-HPLC

Various test methods have been previously documented for determining vitamin A levels in different dosage forms. This study specifically examines an isocratic reverse phase-high performance liquid chromatography (RP-HPLC) method designed for the direct extraction of vitamin A. The objective is to validate an analytical method for quantifying vitamin A in bioadhesive cationic nanoemulsions incorporated into thermosensitive gels. The method employs isocratic RP-HPLC with a YMC-Triart C18 column (L1), dimensions of 4.6 mm × 250 nm, particle size of S-5 µm, and a UV detector at λ = 265 nm. The mobile phase consists of HPLC-grade methanol, acetonitrile, and n-hexane in a ratio of 46.5:46.5:7. Validation parameters were assessed including selectivity, linearity, accuracy, precision, limit of quantification (LOQ), and limit of detection (LOD). Correlation coefficients were determined with an R2 value of 0.9995 in the concentration range of 264–396 μg/mL (w/v). Recovery percentages ranged from 99.295% to 99.878%. Repeatability and intermediate precision relative standard deviations (RSD) were found to be 0.318% and 0.254%, respectively. The LOD was established at 2.018 μg/mL, and the LOQ was determined to be 6.114 μg/mL. The results affirm cost-effective and well-suited for the accurate measurement of vitamin A levels in bioadhesive thermosensitive gel formulations.

PREVALENCE AND MOLECULAR CHARACTERIZATION OF ROTAVIRUS IN MEAT CUTS, AND MEAT HANDLERS IN SELECTED ABATTOIRS IN NAIROBI, KENYA

In Kenya, food screening exercises mostly applies to bacterial and parasitic agents, with enteric viral detection neglected. This study aimed to determine the prevalence and molecular characterization of rotavirus in beef/pork cuts and beef/pork handlers in 4 selected abattoirs in Nairobi. Rotavirus was preferred because of its high prevalence rates and its ability to cause pathophysiologic infective gastroenteritis in humans. It has diverse strains characterized as P and G genotypes based on the VP7 and VP4 proteins, respectively. This cross-section study involved the collection of a total of 467, (165) beef/pork cuts and (302) handlers fecal samples. Collected samples wereprepared before rotavirus identification. Prepared meat and stool suspensions were subjected to direct RNA extraction and EIA detection respectively. All the stool suspensionsand RNA extracted meat suspensions subjected to EIA and Two step RT-PCR were all non-reactive respectively. Therefore, there was no VP4 and VP7 genotyping for characterizationpurposes on confirmed primary PCR products. Eppicollect5 was also used to collect and store the descriptive data of study participants, and the analysis conducted using Power BI statistical software application. The studys findings, indicating no human rotaviral infections in meat cuts, enhance public health by reassuring consumers, guiding regulatory policies, emphasizing the need for ongoing surveillance, directing resources to pressing concerns, supporting safe food handling campaigns, establishing baseline data for future assessments, and encouraging best practices in both formal and informal markets.

Numerical Simulation Study of an Artificial Percolation Riverbed and Its Hydraulic Characteristics under Different Reynolds Numbers

The direct extraction of clear water from a sandy river is a difficult task and can only be achieved through specific engineering measures. This paper proposes an artificial percolation riverbed structure for extracting clean water from sandy rivers, using a numerical simulation to study the flow field distribution characteristics of the structure under clean water conditions. The main conclusions are as follows: When the percolation vortex tube opening rate is 1.4%, the vortex tube with or without opening the percolation hole has little influence on the distribution characteristics of the flow field in the artificial riverbed, and the purpose of water extraction can be achieved while constructing a helical flow field. The axial flow velocity and circumferential flow velocity of the vortex tube cross-section under different Reynolds numbers show the distribution of a low-flow velocity close to the center of the vortex tube, and a high-flow velocity close to the vortex tube side-wall area. The average axial flow velocity and average circumferential flow velocity of the vortex tube show a trend of increasing and then decreasing distribution along the axial axis of the vortex tube in the direction of the sediment transport flume. The mean axial flow velocity of the vortex tube along the axis of the vortex tube toward the sediment transport flume and the mean circumferential flow velocity both show a distribution trend of increasing and then decreasing. At the junction of the vortex tube and the sediment transport flume, there are obvious pressure changes, and the pressure changes drastically under the same horizontal line. Along the direction of the bottom line of the vortex tube, the pressure at the vortex tube is obviously greater than that at the sediment transport flume. The vortex of the artificial percolation riverbed is mainly concentrated in the vicinity of the vortex tube, and the maximum value of the vortex intensity generally occurs at the junction of the vortex tube and the sediment transport flume. With the increase in the Reynolds number, the vortex intensity has an overall increasing trend, and the distribution of the vortex is more complex. This study helps to elucidate the distribution characteristics of the flow field in the artificial percolation riverbed, and it provides a reference basis for the future study of the flow field of artificial percolation riverbeds of sandy rivers.

A direct immersion-solid-phase microextraction method for the automated determination of 3- to 6-ring polycyclic aromatic hydrocarbons in saliva by gas-chromatography-tandem mass spectrometry

This work presents a novel method for the analysis of polycyclic aromatic hydrocarbons (PAHs) in saliva samples using solid phase microextraction (SPME) coupled with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS). The protocol utilizes the latest commercially available overcoated fiber (PDMS/DVB/PDMS) for direct immersion extraction of the target analytes, enabling the determination of thirteen PAHs, including low-volatile compounds. The SPME extraction method was optimized using a central composite design (CCD). The evaluation of the fiber coating's robustness over time demonstrated excellent extraction performance with no significant degradation. The validation procedure confirmed good performance for all parameters, with LOQ values (100 ng/L for ten analytes and 500 ng/L for three analytes) comparable to other chromatographic methods. The environmental impact of the protocol was objectively assessed using two recently proposed metrics: the Green Analytical Procedure Index (GAPI) and the Analytical Greenness metric for sample preparation (AGREEprep). Both metrics indicated good overall environmental friendliness, with AGREEprep providing a satisfactory comprehensive score despite the use of highly impactful instrumentation. These characteristics make the developed method suitable for routine analysis in environmental and epidemiological monitoring.