Semi-quantitative Results Research Articles

Typical Tire Additives in River Water: Leaching, Transformation, and Environmental Risk Assessment.

Tire wear particles (TWPs) released during vehicle driving can enter water bodies, leading to leaching of tire additives (TAs) in aquatic environments. However, the transformation behavior and related ecological impacts of TAs and their transformation products (TPs) remain unclear. In this study, laboratory-based simulation experiments and field investigations were conducted to explore the transformation mechanisms and ecological risks of TAs. After being placed in river water for 24 h, about 7-95% of 12 investigated TAs in TWPs were leached. Forty-eight TPs from eight TAs were tentatively identified along with different transformation pathways via suspect screening by high-resolution mass spectrometry. Semiquantitative results indicated that TPs derived from N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene-diamine (6PPD) were predominant in leachates, while aryl hydrolysis and quinone pathways were the main transformation pathways. Field investigations on urban surface water samples from 16 sites in Hong Kong revealed the occurrence of 17 TAs and 1 TP, with concentrations ranging from 13.9 to 2230 ng/L (median ± standard deviation: 226 ± 534 ng/L). Sixteen TPs from six TAs were additionally identified via suspect screening. It is estimated that 6PPD-quinone and seven TAs could pose medium to high ecological risk, while N-(1,3-dimethylbutyl)-N'-phenyl-p-quinonediimine, a frequently detected TP, was identified as a persistent-bioaccumulative-toxic substance.

B-055 Comparison of two different methods for quantitation of anti-dsDNA antibody

Abstract Background Anti-dsDNA antibody is a specific marker of rheumatic disorder, primarily systemic lupus erythematosus (SLE). Early detection of these diseases is most important in treatment and prognosis. We evaluated two different quantitation systems of anti-dsDNA antibody: the BioPlex 2200 multiplex simultaneous detect system and the single detection method, which is the Phadia 250 system. Methods 53 serum samples were analyzed by two different methods, which are BioPlex 2200, Bio-Rad Laboratories, Hercules, CA, and Padia 250, Thermo Fisher Scientific, Uppsala, Sweden, respectively. The method of the BioPlex 2200 system is multiplexed bead assay, and that of Phadia 250 is Fluorescence Enzyme Immunoassay (FEIA). Results The quantitation results of BioPlexx 2200 were 1 to 126 IU/mL, and those from Phadia 250 were 0.08 to 109.53 IU/mL, respectively. These two groups of the anti-dsDNA antibody values showed excellent correlations (r=0.9036). Conclusions The quantitation of anti-dsDNA antibody were performed mainly by a single analyzing method, Phadia 250, in Korea. Bioplex 2200 system is multiplex bead assay; it can analyze eight different Extractable Nuclear Antigen Antibodies (anti-ENA) simultaneously: Anti Ribosomal P Ab, Anti SSa/Ro Ab, Anti SSb/La Ab, Anti Centromere Ab, Anti Sm Ab, Anti RNP Ab, Anti SCL-70 Ab, Anti Jo-1 Ab as well. Nevertheless, these anti-ENA results showed semiquantitative results.

Superhydrophobic Paper Strips with Embedded Agarose-Anthocyanin Mini-Discs for Point-of-Need Quantitative pH Measurements.

Commercial pH paper is a quick and simple tool for measuring a solution's acidity/basicity, but it only provides qualitative or semi-quantitative results, and the synthetic indicator dyes within can be toxic or carcinogenic. Although pH meters enable more accurate and quantitative analysis, they are less convenient to operate and are tedious to calibrate. This presents a need for an alternative pH testing method for applications where it is not easy or possible to use a pH meter, yet quantitative results are desired. We report herein the fabrication of a pH test strip made from superhydrophobic paper and agarose-anthocyanin film discs. In the proposed method, test strips are dipped into samples and then imaged with a portable scanner (or a smartphone). The color of the film is extracted with ImageJ software (or a mobile app), using the RGB color system. By generating a calibration curve relating the film color to the sample pH using standard buffer solutions, we are able to quantify the pH of beverages and other liquids with an accuracy and precision comparable to that of a pH meter. The test strips offer the same convenience as conventional pH paper, with the added capabilities of quantitation and multiplexed testing, which presents a practical tool for point-of-need pH analysis.

Whole Blood Theophylline Measurements Using an Electrochemical DNA Aptamer-based Biosensor

Theophylline, a bronchodilator used in the treatment of respiratory diseases, displays a narrow therapeutic range requiring therapeutic drug monitoring to maximize its effectiveness and safety. Current measurements of theophylline concentrations are, however, achieved using chromatography or immunoassays, which, in spite of their high accuracy and sensitivity, rely on expensive laboratory-based instruments operated by trained personnel or provide only semi-quantitative results, respectively. In response, we developed an electrochemical DNA aptamer-based (E-AB) sensor for theophylline on screen-printed electrodes. Our sensors enable rapid (<30 s) and selective measurements against theophylline structural analogs in clinically relevant range (55–110 μM) in finger-pricked-sized volumes of undiluted blood samples (<100 μL). Given these attributes, we envision that our results contribute to the development of a low-cost and convenient sensing device for molecular monitoring at the point-of-care.

Applying a mask R-CNN machine learning algorithm for segmenting electron microscope images of ceramic bronze-casting moulds

Material characteristics of casting moulds are crucial for understanding the evolution and diversification of bronze ritual vessel production in Bronze Age China. During relevant studies, a Back Scattered Electron (BSE) image detector is commonly employed to analyze mould microstructure, effectively revealing the volume ratios and shape features of the clay matrix, silt/sand particles, and voids. It is always challenging to analyze and cross-compare these BSE images quantitatively since they typically contain numerous phases with highly irregular shapes. Traditionally, time consuming manual point counting or multi-step image processing were used to obtain semi-quantitative results. Addressing these challenges, we have proposed a deep learning method called BCM-SegNet, an optimized Mask R-CNN-based algorithm for segmenting BSE images of bronze casting moulds and cores. Using the proposed method, key parameters, such as area, Feret diameter, roundness, and solidity of segmented particles, can be provided based on well segmented results, even for the images with complex background. Experimental outcomes show that the algorithm achieves a segmentation precision of 95% and an accuracy of around 91%, demonstrating its strong generalization capability. This study provides a significant foundation for micro-feature analysis of archaeological ceramic materials, classification of particles, and determination of technological processes in archaeological research.

Pushing the Limits of Lateral Flow Immunoassay by Digital SERS for the Ultralow Detection of SARS‐CoV‐2 Virus

Lateral flow immunoassays (LFIAs) are easy‐to‐use antigen tests that provide different signal readouts, with colorimetric readouts being the most commonly used. However, these analytical devices have relatively low sensitivity and produce semiquantitative results, limiting their diagnostic applications. Herein, we address these challenges by implementing a digital surface‐enhanced Raman spectroscopy (SERS)‐based LFIA for the accurate and ultrasensitive quantitative detection of SARS‐CoV‐2 nucleocapsid (N) protein. Compared with average SERS intensity measurements, the digital approach allowed to overcome fluctuations in Raman scattering signals, thereby increasing the analytical sensitivity of the assay. Our method exhibited a quantification range of the viral protein in nasal swabs from 0.001 to 10 pg mL−1, and a limit of detection down to 1.9 aM (0.9 fg mL−1), improving colorimetric LFIAs and conventional‐SERS‐based LFIAs by several orders of magnitude. Importantly, this approach shows an analytical sensitivity of 0.03 TCID50 mL−1, which is greater than that reported by other immunoassays. In conclusion, we successfully demonstrate the robust detection and quantification of SARS‐CoV‐2N protein in nasal swabs at ultralow concentrations. The improvement in the sensitivity of LFIA by digital SERS may pave the way to translate this technology into the diagnostic arena for the ultrasensitive detection of microbes and disease biomarkers.

Validation of two LC[sbnd]HRMS methods for large-scale untargeted metabolomics of serum samples: Strategy to establish method fitness-for-purpose

Untargeted metabolomics by LCHRMS is a powerful tool to enhance our knowledge of pathophysiological processes. Whereas validation of a bioanalytical method is customary in most analytical chemistry fields, it is rarely performed for untargeted metabolomics. This study aimed to establish and validate an analytical platform for a long-term, clinical metabolomics study. Sample preparation was performed with an automated liquid handler and four analytical methods were developed and evaluated. The validation study spanned three batches with twelve runs using individual serum samples and various quality control samples. Data was acquired with untargeted acquisition and only metabolites identified at level 1 were evaluated. Validation parameters were set to evaluate key performance metrics relevant for the intended application: reproducibility, repeatability, stability, and identification selectivity, emphasizing dataset intrinsic variance. Concordance of semi-quantitative results between methods was evaluated to identify potential bias. Spearman rank correlation coefficients (rs) were calculated from individual serum samples. Of the four methods tested, two were selected for validation. A total of 47 and 55 metabolites (RPLC-ESI+- and HILIC-ESI−-HRMS, respectively) met specified validation criteria. Quality assurance involved system suitability testing, sample release, run release, and batch release. The median repeatability and within-run reproducibility as coefficient of variation% for metabolites that passed validation on RPLC-ESI+- and HILIC-ESI−-HRMS were 4.5 and 4.6, and 1.5 and 3.8, respectively. Metabolites that passed validation on RPLC-ESI+-HRMS had a median D-ratio of 1.91, and 89 % showed good signal intensity after ten-fold dilution. The corresponding numbers for metabolites with the HILIC-ESI−-HRMS method was 1.45 and 45 %, respectively. The rs median ({range}) for metabolites that passed validation on RPLC-ESI+- was 0.93 (N = 9 {0.69–0.98}) and on HILIC-ESI−-HRMS was 0.93 (N = 22 {0.55–1.00}). The validated methods proved fit-for-purpose and the laboratory thus demonstrated its capability to produce reliable results for a large-scale, untargeted metabolomics study. This validation not only bolsters the reliability of the assays but also significantly enhances the impact and credibility of the hypotheses generated from the studies. Therefore, this validation study serves as a benchmark in the documentation of untargeted metabolomics, potentially guiding future endeavors in the field.

Lateral flow assay for simultaneous detection of multiple mycotoxins using nanozyme to amplify signals

Co-contamination of multiple mycotoxins produces synergistic toxic effects, leading to more serious hazards. Therefore, the simple, rapid and accurate simultaneous detection of multiple mycotoxins is crucial. Herein, a three-channel aptamer-based lateral flow assay (Apt-LFA) was established for the detection of aflatoxin M1 (AFM1), aflatoxin B1 (AFB1) and ochratoxin A (OTA). The multi-channel Apt-LFA utilized gold‑iridium nanozyme to catalyze the chromogenic substrate, which effectively achieved signal amplification. Moreover, the positions and lengths of the complementary sequences were screened by changes in fluorescence intensity. After grayscale analysis, the semi-quantitative results showed that the detection limits of AFM1, AFB1 and OTA were 0.39 ng/mL, 0.36 ng/mL and 0.82 ng/mL. The recoveries of the multiplexed competitive sensors in complex matrices of real samples were 93.33%–97.01%, 95.72%–102.67%, and 106.88%–109.33%, respectively. In conclusion, the assembly principle of the three-channel Apt-LFA is simple, which can provide a new idea for the simultaneous detection of small molecule targets.

Semiquantitative Paper-Based Microfluidic Surrogate Virus Neutralization Test for SARS-CoV-2 Neutralizing Antibodies.

Neutralizing antibodies (nAbs) produced from infection or vaccination play an important role in acquired immunity. Determining virus-specific nAb titers is a useful tool for measuring aquired immunity in an individual. The standard methods to do so rely on titrating serum samples against live virus and monitoring viral infection in cultured cells which requires high biosafety level containment. The surrogate virus neutralization test (sVNT) reduces the biohazards and it is suitable for designing rapid test device in a lateral flow assay (LFA) format. Here, we introduce the fabrication and development of a unique paper-based LFA device for determining the level of SARS-CoV-2 nAb in a sample with a semiquantitative direct colorimetric readout. A LFA-based gradient assay design was used to facilitate the sVNT, where the spike glycoprotein receptor binding domain (RBD) and angiotensin-converting enzyme 2 (ACE2) stand in as proxies for viruses and cells, respectively. The gradient assay employed multiple test dots of ACE2 spotted in increasing concentration along the sample flow path and gold nanoparticle-conjugated RBD for readout. In this way, the number of developed spots is inversely proportional to the concentration of nAbs present in the sample. The assay was tested with both standard solutions of nAb as well as human serum samples. We have demonstrated that the device can effectively provide semiquantitative test results of nAbs by direct instrument-free colorimetric detection.

Electrochemical Lateral Flow Immunoassay with Built-In Electrodes for Ultrasensitive and Wireless Detection of Inflammatory Biomarkers.

Paper-based lateral flow immunoassays (LFIAs) are cost-effective, portable, and simple methods for detection of diverse analytes, which however only provide qualitative or semiquantitative results and lack sufficient sensitivity. A combination of LFIA and electrochemical detection, namely, electrochemical lateral flow immunoassay (eLFIA), enables quantitative detection of analytes with high sensitivity, but the integration of external electrodes makes the system relatively expensive and unstable. Herein, the working, counter, and reference electrodes were prepared directly on the nitrocellulose membrane using screen printing, which remarkably simplified the structure of eLFIA and decreased the cost. Moreover, a horseradish peroxidase (HRP)-based electrochemical signal amplification strategy was used for further increasing the analytical sensitivity. HRP captured on the working electrode can catalyze the oxidation of tetramethylbenzidine (TMB) to form the TMB-TMBox precipitate on the electrode surface, which as an electrochemically active product can output an amplified current for quantification. We demonstrated that the eLFIA could detect low-abundant inflammatory biomarkers in human plasma samples with limits of detection of 0.17 and 0.54 pg mL-1 for interleukin-6 and C-reactive protein, respectively. Finally, a fully portable system was fabricated by integrating eLFIA with a flexible and wireless electrochemical workstation, realizing the point-of-care detection of interleukin-6.

A novel, green and affordable semi-quantitative limit test for 2-aminobutanol impurity in ethambutol hydrochloride bulk and tablets

The pharmacopoeial limit test for the impurity 2-aminobutanol (AB) in ethambutol hydrochloride (ETB) relies on florescence measurement using a fluorometer. However, this instrument is often unavailable in many laboratories due to its cost. A novel colorimetric method was therefore developed using genipin, an amine-reactive reagent, to react with AB, producing a blue color. The color intensity was subsequently measured using a more affordable UV-vis spectrophotometer. To overcome matrix effects, the standard addition technique was incorporated. The test effectively detected AB at concentrations as low as 0.125% in ETB, below the compendial limit of 1.0%. The analysis of ETB bulk and tablets showed consistent semi-quantitative results with the USP method. Furthermore, it aligned with green chemistry by eliminating the use of organic solvents and employing safe, naturally derived reagent. In summary, the proposed method provides a reliable, green, and cost-effective alternative for analyzing AB in ETB, ensuring compliance with pharmacopeial standards.

Accuracy of screening for hemolysis in plasma samples using a commercial urine dipstick

Objectives: Identification and quantification of hemolysis in serum or plasma samples is an important requirement in laboratory diagnostics; however, this is not always possible automatically, and visual sample inspection is not sufficiently accurate. We have planned this study to determine whether a commercially available urine dipstick with a hemoglobin-reactive pad could be used for this purpose. Materials and Methods: Sixty-five routine plasma samples, whose hemolysis index (HI) was previously determined on Roche Cobas 8000, were assayed with a commercial urine dipstick to obtain semi-quantitative data on plasma hemoglobin. Plasma was diluted 1:1000 in water to enter the dipstick’s range of hemoglobin measurement, and 10 µL of this dilution was applied to the hemoglobin pad. Results were visually interpreted within 60 s by comparing the pad color with that on the dipstick box label. Statistical Analysis: Semi-quantitative test results obtained with the urine dipstick were directly correlated with those of the same samples assayed on Roche Cobas 8000 using non-parametric Spearman’s correlation and agreement. Results: The sample size consisted of 40 non-hemolyzed (HI ≤0.3 g/L) and 25 hemolyzed (HI &gt;0.3 g/L) plasma samples. Spearman’s correlation between Cobas HI and dipstick hemoglobin concentration was r = 0.96 (95% confidence interval, 0.93–0.97; P &lt; 0.001). The concordance of hemolysis detection was 95.4%, with 1.00 sensitivity, 0.93 specificity, 1.00 negative predictive value, and 0.89 positive predictive value compared to the reference HI measurement on Cobas. The cumulative agreement between Cobas HI and the various plasma hemoglobin thresholds obtained with the dipstick was 75.4%. Conclusions: We have demonstrated here that plasma hemoglobin assessment with commercially available urine dipsticks may generate semi-quantitative test results accurate enough to influence decision-making regarding sample quality and its suitability for testing.

A molecular and computational study of galbanic acid as a regulator of Sirtuin1 pathway in inhibiting lipid accumulation in HepG2 cells

Introduction Sirtuin1 (SIRT1) plays a crucial role in the pathophysiology of non-alcoholic fatty liver disease. We investigated the mechanistic role of galbanic acid (Gal) as a regulator of SIRT1 in silico and in vitro. Methods HepG2 cells were treated with Gal in the presence or absence of EX-527, a SIRT1-specific inhibitor, for 24 h. Sirtuin1 gene and protein expression were measured by RT-PCR and Western blotting, respectively. It has been docked to the allosteric reign of SIRT1 (PDB ID: 4ZZJ) to study the effect of Gal on SIRT1, and then the protein and complex molecular dynamic (MD) simulations had been studied in 100 ns. Results The semi-quantitative results of Oil red (p < .03) and TG level (p < .009) showed a significant reduction in lipid accumulation by treatment with Gal. Also, a significant increase was observed in the gene and protein expression of SIRT1 (p < .05). MD studies have shown that the average root mean square deviation (RMSD) was about 0.51 Å for protein structure and 0.66 Å for the complex. The average of radius of gyration (Rg) is 2.33 and 2.32 Å for protein and complex, respectively, and the pattern of root mean square fluctuation (RMSF) was almost similar. Conclusion Computational studies show that Gal can be a great candidate to use as a SIRT1 ligand because it does not interfere with the structure of the protein, and other experimental studies showed that Gal treatment with SIRT1 inhibitor increases fat accumulation in HepG2 cells.

Abstract PO4-03-08: Enhanced Assessment of Clinical Behavior of TNBC and TPBC using Quantified Levels of HER2, Estrogen and Progestin Receptor Proteins and Expression of Their Cognate Genes

Abstract Background: Renewed interest in clinical relevance of low-HER2 protein in breast cancer management prompted a retrospective investigation of a unique de-identified Database of quantified biomarkers associated with patient outcomes. Currently, IHC of ER, PR and HER2 proteins provides semi-quantitative results, at times complicated by variation in methods and interpretation (cf. ASCO/CAP Guidelines). Our goal was to ascertain relationships of these clinical analytes to predict cancer relapse when quantified for protein products and cognate gene expression. Methods: Database contained 2756 quantified HER2 results by ELISA (Oncogene Sciences) or by EIA (Triton Diagnostics) of which 198 patients had associated clinical outcomes. No definition of HER2-low has been accepted for IHC, although &amp;gt; 50% of biopsies may be categorized as HER2-low (cf. ASCP CE Programs). Microarray results obtained for ~ 22,000 genes using RNA purified from LCM-procured carcinoma cells of 247 primary breast biopsies were analyzed. ESR1, PGR and ERBB2 gene expression levels in 276 biopsies had been validated by RTqPCR. To assess distribution and dispersion of HER2 protein, cumulative relative frequency distribution analyses were employed, focusing on cut-offs within interquartile range. Permutations and combinations of the 3 biomarkers based on IHC definitions (cf. ASCO/CAP Guidelines) were examined. Tertiles and quartiles of data sets were used to explore association between biomarker levels and clinical outcomes. Box plots depicted protein and gene expression levels, Progression-Free Survival (PFS), or Overall Survival (OS) across ER/PR/HER2 categories and compared differences using a Kruskal-Wallis ANOVA Rank Test. Cox regressions were used to contrast hazard ratios among the ER/PR/HER2 groups. Kaplan-Meier plots visualized survival rates among groups and a log-rank test detected statistical discrepancies. We investigated differences between groups for categorical variables using chi-squared tests (Fisher's exact test for non-normally distributed data), while for ordinal variables, ANOVA tests were used (Kruskal-Wallis for non-normally distributed data). Categorical variables were summarized as count (%), and ordinal variables were summarized as median [IQR]. Analyses were performed using R version 4.2.2 (Innocent and Trusting). Results: Neither quantified ER or PR alone nor ER/PR collectively were related to HER2 oncoprotein levels. Influence of menopausal status on biopsy biomarker profiles was investigated. With a median cutoff for HER2 protein, patients with ER+/PR+/HER2+ (TPBC) exhibited increased OS, whereas those with TNBC had decreased OS, of 8 combinations possible. Using tertiles and quartiles, TPBC was exhibited by 34-37% of specimens compared to TNBC, which represented 9.1-12.7% of biopsies when biomarker proteins were quantified. After qPCR data were stratified by ER/PR/HER2 status with a 50% quantile cut for HER2, 39% were TPBC and 10% were TNBC. Using microarray data with the same cutoffs, only 14% were TPBC and 17% were TNBC. Once TPBC were identified by either microarray or by qPCR, increased ESR1, PGR and ERBB2 expression collectively was associated with increased PFS and OS of patients. In general, biopsies that were TNBC or other combinations of biomarker’s gene expression correlated with poorer prognosis and overall survival. Conclusions: Quantifying levels of ER, PR and HER2 proteins as well as of ESR1, PGR and ERBB2 expression were correlated with prediction of clinical outcomes of TNBC, TPBC and patients with other biomarker subsets. Results support quantitative assessment of these biomarkers in biopsies to assess utility of the HER2-low type in personalizing breast cancer management and prediction of risk of relapse. Citation Format: James Wittliff, Michael Daniels. Enhanced Assessment of Clinical Behavior of TNBC and TPBC using Quantified Levels of HER2, Estrogen and Progestin Receptor Proteins and Expression of Their Cognate Genes [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-03-08.

Development and validation of a quantitative minilab system for quality evaluation of selected medicines: Albendazole, arthemether-lumefantrine combination (Co-artem®), and mebendazole finished pharmaceutical products

AbstractThe current technologies for substandard and counterfeit drug detection are either too expensive for low-resource settings or only provide qualitative or semi-quantitative results. GPHF minilab™ is one of them based on thin layer chromatography(TLC) principles with a semi-quantitative capability by visual observation of the spot area and intensity for medicine quality analysis. Thus, its use as a quality control tool for pharmaceutical products has limitations as spot area and intensity visual observation by the naked eye highly varies from analyst to analyst. As such, in this study, the semi-quantitative technique has been transferred to a quantitative approach by capturing the developed TLC plate image using an Android-based mobile phone inside a simple carton box. Then, the spot area was quantified using justTLC software. The quantitative results were compared with the-high performance liquid chromatography (HPLC) method as the golden standard. Accordingly, linearity was observed in the assayed range (80–120% label claim), and the correlation coefficients found were (R2 = 0.958, 0.997, 0.941, and 0.956 for Albendazole, Mebendazole, Artemether, and Lumefantrine, respectively.). The values are satisfactory. The %RSDs found were less than 2% for all drugs [intraday (n = 6) (RSD = 1.17, 1.61, 1.87, and 1.64), and interday (n = 18) (RSD = 1.16, 0.72, 1.12, and 1.18) for Artemether, Lumefantrine, Mebendazole, and Albendazole, respectively]. Moreover, comparisons of results obtained from the sophisticated CAMAG UV cabinet (R2 =0.991, 0.971, 0.946, and 0.967) and the developed simple carton box (R2 = 0.958, 0.997, 0.941, and 0.956) for Albendazole, Mebendazole, Artemether, and Lumefantrine, respectively. The values are comparable and reveal the accuracy of the method. Robustness testings' that were performed under different altered conditions revealed the robustness of the method (RSD less than 2% for all factors). Additionally the deviations from the golden HPLC results were on average −8.62% for albendazole, −3.79% for artemether, and −4.52% for lumefantrine samples. The developed method shows a satisfactory performance capability to utilize the GPHF minilab™ as a quantitative technique for medicine quality control purposes. It will be a very useful tool in a resource-limited setting. The target method profile, which encompasses a simple, low-cost, linear, precise, robust, accurate, and quantitative GPHF minilab™ system, was obtained for Albendazole, Mebendazole, and Arthemeter lumefantine combinations (Co-artem). The proposed method was successfully applied to analyze the content of the marketed medicines in the above mentioned tablets and offered acceptable deviations from the golden HPLC method. Automation of quantitative GPHF minilab™ was highly recommended to enhance the appropriateness and use of this system.

Anthropogenic-induced ecological risks on marine ecosystems indicated by characterizing emerging pollutants in Pearl River Estuary, China

Anthropogenic Contaminants of Emerging Concern (CECs) in marine environments have raised significant concerns. Yet, analyses detailing their origins, fate, and environmental effects are limited. This study employs an integrated non-target screening methodology to elucidate CECs existence across 46 sampling sites in the Pearl River Estuary (PRE) of the South China Sea. Assisted by advanced liquid chromatography-high resolution mass spectrometry, we discovered 208 chemicals in six usage categories, with pesticides (33 %) and pharmaceuticals (29 %) predominating. Several CECs drew attention for their consistent detections, profound abundance, and significant ecotoxicities. The wide detection of them at offshore sites further implies that anthropogenic activities may contribute to large-scale contamination. Meanwhile, distinct distribution patterns of CECs across PRE are evident in semi-quantitative results, indicating regional anthropogenic influences. Identified transformation products may establish a novel and non-negligible negative contribution to ecology through elevated environmental toxicities, exemplified by HMMM and atrazine. Based on the ecological risks, we compiled a prioritized list of 21 CECs warranting intensified scrutiny. Our findings indicate the introduction of various CECs into the South China Sea via PRE, emphasizing the urgent necessity for ongoing surveillance of discharged CECs at estuary areas and assessment of their marine ecological consequences.

Relationships between Motor Skills and Academic Achievement in School-Aged Children and Adolescents: A Systematic Review.

This review systematically summarizes the studies of the relationship between primary-to-secondary school students' motor skills and academic achievement, and analyzes the relationship between gross and fine motor skills and performance in different subjects. Five electronic databases, Web Of Science, PubMed, PsycINFO, SPORTDiscus, and Academic Search Premier, were searched in March 2023. Semi-quantitative assessment methods were used to analyze the results of the included studies. Seventy-eight articles were included in this systematic review. The semi-quantitative assessment results showed that gross (+, 65.0/62.5%) and fine motor skills (+, 83.3/80%) were positively correlated with overall performance and language performance, with ≥60% of the associations in the same direction. For different subjects, fine motor skills were positively correlated with students' mathematics (+, 75.0%), reading (+, 72.7%), writing (+, 66.7%), and spelling (+, 60.0%) scores. However, the association between gross motor skills and students' mathematics achievement (?, 52.8%), reading (?, 53.8%), and spelling (?, 50.0%) is uncertain, with <60% of the associations in the same direction. It is wise to direct our gaze toward the evolution of motor skills among students, especially primary school students. Different motor skill intervention modes should be selected in a targeted manner according to different subject achievements.

Targeted sequencing from cerebrospinal fluid for rapid identification of drug-resistant tuberculous meningitis.

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.

Chemical characterization of refuse derived fuel (RDF) using Py-GC/MS

The conversion of municipal solid waste (MSW) to refuse-derived fuel (RDF) and its utilization as an alternative fuel in the cement industry has been an emerging trend. However, RDF is highly heterogeneous, with its complex composition changing with season and source. This work is focused on the chemical characterization of six RDF samples listed as A, B, C, D, E, and F from different locations across the country using pyrolysis gas chromatography-mass spectrometry (Py-GC/MS), thermogravimetric instrument and CHONS elemental analyzer. Qualitative and semi-quantitative results were obtained using EGA, single-shot and double-shot analysis methods. EGA has been used to derive qualitative results in correlation with TGA. FTIR analysis was carried out to understand the initial functional characterization. XRF analysis along with ICP-MS triple quad revealed the inorganic makeup of the samples. Single-shot results indicated that apart from non-hydrocarbon gases (CO2 and O2), the long-chain alkenes were most abundant, followed by alkanes, aromatic compounds, and ketones. Double-shot analysis indicated the presence of chloride and sulphur-based compounds in RDF samples as limiting components. Polystyrene contribution to LHV of RDF has been highlighted. The study can be further used to conduct compositional studies of RDF and its pyrolytic behavior in the gasifier. It will further strengthen the future gasifier models where pyrolysis is one of the critical steps. This technique will be very helpful in obtaining a better characterization of volatile and non-volatile (bio-oil and ash) fractions of the pyrolytic products.

Microstructure and mechanical properties of laser welded and post-weld heat-treated K439B superalloy

Laser welding of the new nickel-based alloy K439B applied for engine turbine was carried out. The effects of post-welding heat treatment (PWHT) on the microstructure and mechanical properties of the joints were investigated. Semi-quantitative statistical results show that after PWHT, γ’ phases in the whole joint grow up, and the radii of the primary and secondary γ’ phases are about 25 and 150 nm, respectively. The results of mechanical properties show that PWHT improves the microhardness in the weld by about HV 100, and the critical resolved shear stress provided by γ’ phases increases from 4.8 to 92 MPa. The tensile strength and yield strength of the heat-treated joint are comparable to those of the base metal. The presence of a large amount of carbides is the reason for the preferential fracture of the base metal during the tensile process.