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Teaching innovations in lipid science
\"Filled with practical strategies and exciting experiments, Teaching Innovations in Lipid Science addresses lipid education at a range of levels from the novice to the graduate student and teacher. Peer-reviewed contributions from internationally known specialists describe several methods and approaches designed to create new lipid courses, modify existing courses, and serve as a basis for pursuing novel avenues of instruction.\"--BOOK JACKET.
Book
Multi-residue analytical methods for pesticides in teas: a review
Tea is one of the most popular drinks worldwide. In the process of tea planting, for controlling pests, a variety of pesticides are usually applied. Therefore, pesticide residues and their metabolites in tea leaves, as well as their adverse effects on tea drinkers' health, are becoming increasingly concerning. The tea-leaf matrix is very complex because it is rich in organic acids, polyphenols, natural pigments, catechins, flavonols, metallic/non-metallic elements, and other unconfirmed substances. Hence, it is a great challenge to conduct multi-residue analysis of pesticides in tea samples. Researchers worldwide have been devoted to the development of multi-residue analytical methods for pesticide detection in tea and have made great progress in recent years. In this review, the recent advances in the multi-residue analysis of pesticides in tea matrices, especially those regarding matrix effects and their elimination, sample preparation and detection techniques, were reviewed in depth, and future research directions were suggested as well.
Journal Article
A scoping review finds a growing trend in studies validating multimorbidity patterns and identifies five broad types of validation methods
Multimorbidity, the presence of two or more long-term conditions, is a growing public health concern. Many studies use analytical methods to discover multimorbidity patterns from data. We aimed to review approaches used in published literature to validate these patterns.
We systematically searched PubMed and Web of Science for studies published between July 2017 and July 2023 that used analytical methods to discover multimorbidity patterns.
Out of 31,617 studies returned by the searches, 172 were included. Of these, 111 studies (64%) conducted validation, the number of studies with validation increased from 53.13% (17 out of 32 studies) to 71.25% (57 out of 80 studies) in 2017–2019 to 2022–2023, respectively. Five types of validation were identified: assessing the association of multimorbidity patterns with clinical outcomes (n = 79), stability across subsamples (n = 26), clinical plausibility (n = 22), stability across methods (n = 7) and exploring common determinants (n = 2). Some studies used multiple types of validation.
The number of studies conducting a validation of multimorbidity patterns is clearly increasing. The most popular validation approach is assessing the association of multimorbidity patterns with clinical outcomes. Methodological guidance on the validation of multimorbidity patterns is needed.
Journal Article
Recent developments in mass spectrometry for the characterization of micro- and nanoscale plastic debris in the environment
Development of analytical methods for the characterization (particle size determination, identification, and quantification) of the micro- and nanoscale plastic debris in the environment is a quickly emerging field and has gained considerable attention, not only within the scientific community, but also on the part of policy makers and the general public. In this Trends paper, the importance of developing and further improving analytical methodologies for the detection and characterization of sub-20-μm-range microplastics and especially nanoplastics is highlighted. A short overview of analytical methodologies showing considerable promise for the detection and characterization of such micro- and nanoscale plastic debris is provided, with emphasis on recent developments in mass spectrometry (MS)–based analytical methods. Novel hyphenated techniques combining the strengths of different analytical methods, such as field flow fractionation and MS-based detection, may be a way to adequately address the smallest fractions in plastic debris analysis, making such approaches worthwhile to be further explored.
Journal Article
Mechanism and Law Analysis on Ground Settlement Caused by Shield Excavation of Small-Radius Curved Tunnel
The mechanism of ground settlement caused by the construction of small-radius curved tunnels is more complicated compared to straight tunnels. This paper takes Changzhou Metro Line 2 as an example, comprehensively considers the additional thrust of the tunnel face, the grouting pressure of the shield tail, the friction between the shield shell and surrounding soil, and the ground loss. The analytical methods, numerical simulation and field measurement are used to compare and study the law of ground settlement of small-radius curved tunnels. The results show that the main factors that induce surface deformation during shield construction of small-radius curved tunnels are ground loss and shield shell friction. The ground settlement caused by the ground loss accounts for about 90% of the total settlement, while the shield shell friction mainly causes ground heave. The deformation of the transverse plane of the tunnel is distributed asymmetrically along the tunnel axis, showing a curved shape with a small radius, and the ground settlement in front of the tunnel shows a “W” shape. Meanwhile, the ground settlement is negatively correlated with the increase in the radius of curvature. As the radius of the curve decreases, the surrounding soil of the curved tunnel shows a tendency to tilt toward the tunnel. This research can provide basis and data support for the ground settlement prediction of shield construction of small-radius curved tunnel.HighlightsCombined with analytical method, numerical simulation and field measured data, the prediction method of ground settlement caused by shield tunneling in small-radius curved tunnel is discussed.Considering factors such as additional thrust, grouting pressure, the shield shell friction, and ground loss, the law of ground settlement during shield construction of small-radius curved tunnels are studied.In the process of shield construction of small-radius curved tunnel, the main inducing factor of ground settlement is ground loss, the main inducing factor of the ground heave is the friction of the shield shell.
Journal Article
Recent Advances in Analytical Methods for Determination of Polyphenols in Tea: A Comprehensive Review
Polyphenols, the most abundant components in tea, determine the quality and health function of tea. The analysis of polyphenols in tea is a topic of increasing interest. However, the complexity of the tea matrix, the wide variety of teas, and the difference in determination purposes puts forward higher requirements for the detection of tea polyphenols. Many efforts have been made to provide a highly sensitive and selective analytical method for the determination and characterization of tea polyphenols. In order to provide new insight for the further development of polyphenols in tea, in the present review we summarize the recent literature for the detection of tea polyphenols from the perspectives of determining total polyphenols and individual polyphenols in tea. There are a variety of methods for the analysis of total tea polyphenols, which range from the traditional titration method, to the widely used spectrophotometry based on the color reaction of Folin–Ciocalteu, and then to the current electrochemical sensor for rapid on-site detection. Additionally, the application of improved liquid chromatography (LC) and high-resolution mass spectrometry (HRMS) were emphasized for the simultaneous determination of multiple polyphenols and the identification of novel polyphenols. Finally, a brief outline of future development trends are discussed.
Journal Article
A novel analytical approach to micro-polar nanofluid thermal analysis in the presence of thermophoresis, Brownian motion and Hall currents
The present study analyzed micro-polar nanofluid in a rotating system between two parallel plates with electric and magnetic fields. The fluid flow study was performed in a steady state. The governing equations of the present issue are considered coupled and nonlinear equations with proper similar variables. Numerical and new semi-analytical methods have been employed to solve the problem to define the exactness of the results. The influence of physical parameters governing the problem is investigated and illustrated in detail in the diagram. Results show that velocity profile and micro-rotation velocity increased when the magnetic parameter increased. Furthermore, the velocity is increased by increasing the rotation parameter. Also, in the case of the temperature profile, the Reynolds and Schmidt numbers have an inverse effect, and Prandtl number and Brownian motion have a direct effect. Other results indicate that concentration value declines by increasing the thermophoretic parameter and Reynolds number. Results compared to the prior research display good accuracy and efficiency. The study demonstrates that the method provides quantifiable reliable outcomes while requiring less computing work than conventional techniques. This method offers significant advantages in terms of simplicity, applicability, computational efficiency and accuracy.
Journal Article
Stress and stiffness analysis of the multiple corrugated diaphragm under angular load based on plate and shell theory
The Multiple Corrugated Diaphragm(MCD) couplings, as a new type of flexible coupling, exhibit complex non-axisymmetric mechanical characteristics under angular loads due to their sinusoidal corrugated structure, posing challenges to traditional analytical methods. This paper aims to establish an efficient analytical model based on plate and shell theory to predict the stress distribution and angular stiffness of the MCD under angular loads. The study combines analytical methods with the finite element method (ANSYS), segments the corrugations, and establishes reasonable boundary conditions to derive analytical formulas for the deflection curve, stress distribution, and stiffness calculation at the maximum deformation section. The results show that the analytical model calculations are highly consistent with finite element simulations: the deflection curves follow similar trends, the stress distribution patterns generally match, and the angular stiffness calculation error is within 7%. The findings indicate that the established analytical model effectively captures the core mechanical behavior of the MCD, providing a reliable theoretical basis for the rapid design and optimization of high-performance MCD Couplings.
Journal Article
Development and validation of a highly effective analytical method for the evaluation of the exposure of migratory birds to antibiotics and their metabolites by faeces analysis
Abstract The widespread occurrence of antibiotics in the environment may exert a negative impact on wild organisms. In addition, they can become environmental reservoirs, through the ingestion of food or contaminated water, and vectors for antibiotic-resistant bacteria. This fact is even more important in migratory birds that can promote their dissemination across continents. In this work, a multiresidue analytical method suitable for the determination of five families of antibiotics and their main metabolites in waterbird faeces has been developed and validated. The target compounds include environmentally significant sulfonamides, macrolides, fluoroquinolones, tetracyclines and antifolates. Sample treatment involves ultrasound-assisted extraction with methanol and dispersive solid-phase extraction clean-up with C18. Analytical determination was carried out by liquid chromatography–tandem mass spectrometry. The most significant parameters affecting sample extraction and extract clean-up were optimised by means of experimental designs. Good linearity (R2 > 0.994), accuracy (from 41 to 127%), precision (relative standard deviation lower than 24%) and limits of quantification (lower than 2 ng g−1 (dry weight, dw)) were obtained for most of the compounds. The method was applied to the determination of the selected compounds in 27 faeces samples from three common migratory waterbird species. Nine antibiotics and three of their metabolites were detected in the analysed samples. Fluoroquinolones and macrolides were the antibiotics most frequently detected. The highest concentrations corresponded to norfloxacin (up to 199 ng g−1 dw).
Journal Article
Assessment of volatile component stability in Guanxin Jieyu granules through gas chromatography in accordance with Q14 guidelines
Guanxin Jieyu Granules, a novel traditional Chinese medicine (TCM) in development, targets stable angina pectoris with accompanying anxiety. To improve stability, its volatile oil components—including borneol—are stabilized via β-cyclodextrin inclusion. In compliance with ICH Q14 guidelines, a gas chromatography (GC) analytical method was developed, incorporating knowledge management, risk management, experimental design, and results analysis, as well as performance evaluation of the analytical method. Accelerated Destructive Degradation Tests (ADDTs) using this method revealed a dramatic stability enhancement from β-cyclodextrin encapsulation. At 25 °C over 730 days, the inclusion complex showed only a 1.10% probability of failure (defined as ≥ 5% content loss), compared to 88.50% for the physical mixture. These results underscore the critical role of cyclodextrin inclusion in preserving volatile TCM constituents.
Journal Article