Quantitative Determination Research Articles

Development of a time-resolved immunochromatographic test strip for rapid and quantitative determination of GFAP in serum.

Glial fibrillary acidic protein (GFAP) in serum has been shown as a biomarker of traumatic brain injury (TBI) which is a significant global public health concern. Accurate and rapid detection of serum GFAP is critical for TBI diagnosis. In this study, a time-resolved fluorescence immunochromatographic test strip (TRFIS) was proposed for the quantitative detection of serum GFAP. This TRFIS possessed excellent linearity ranging from 0.05 to 2.5 ng/mL for the detection of serum GFAP and displayed good linearity (Y = 598723X + 797198, R2 = 0.99), with the lowest detection limit of 16 pg/mL. This TRFIS allowed for quantitative detection of serum GFAP within 15 min and showed high specificity. The intra-batch coefficient of variation (CV) and the inter-batch CV were both < 4.0%. Additionally, this TRFIS was applied to detect GFAP in the serum samples from healthy donors and patients with cerebral hemorrhage, and the results of TRFIS could efficiently discern the patients with cerebral hemorrhage from the healthy donors. Our developed TRFIS has the characteristics of high sensitivity, high accuracy, and a wide linear range and is suitable for rapid and quantitative determination of serum GFAP on-site.

Experimental design approach for the quantitative analysis of multicomponents by single marker and HPLC fingerprinting of Thunbergia laurifolia aqueous extract.

Thunbergia laurifolia is used in traditional Thai medicine to reduce fever and treat mouth ulcers. However, the quantitative analysis of chemical markers has not yet been officially defined. The objective of this study is to develop a high-performance liquid chromatography (HPLC) method using a design of experiment (DoE) for the quantitative analysis of multicomponents by single marker (QAMS) and fingerprinting of the T. laurifolia aqueous extract. Critical variables were screened using a two-level fractional factorial design, followed by the optimization of the selected variables using a central composite design. The validated method was applied for quality assessment based on QAMS and fingerprinting of the extract. Optimum conditions of DoE for the analysis of caffeic acid, vicenin-2, and rosmarinic acid were determined. The relative correction factors for caffeic acid and vicenin-2 were calculated using rosmarinic acid as an internal reference standard, and their contents in 30 samples were determined. The differences between the external standard method (ESM) and QAMS were compared. No significant difference was observed in the quantitative determination, proving the consistency QAMS and ESM. HPLC fingerprints of T. laurifolia were established with 8 of 12 characteristic peaks that were structurally characterized using HPLC-diode array detection-electrospray ionization/tandem mass spectrometry. The similarity of the fingerprints in all samples was ≥0.74, and the pattern recognition of the characteristic peaks was satisfied. The proposed method efficiently detected multiple components of the T. laurifolia extract. Thus, the method is beneficial in providing references for enhancing the quality control of other herbal medicines.

ИЗУЧЕНИЕ ВАЛИДАЦИОННЫХ ХАРАКТЕРИСТИК МЕТОДИК ИСПЫТАНИЯ НА ПОДЛИННОСТЬ И КОЛИЧЕСТВЕННОГО ОПРЕДЕЛЕНИЯ АЦИЗОЛА В СТОМАТОЛОГИЧЕСКОМ ГЕЛЕ

In the quality assurance system for medicinal products, an important role is played by the procedure for validation of analytical methods at the stages of development, testing, technology and serial production. The need for validation at the stage of drug development is due to the fact that it is possible to promptly identify the shortcomings of the method and significantly improve it. The purpose of this study is to validate methods for testing «The authenticity» and «Quantitative determination» of acyzole in dental gel. Materials and methods. To achieve this goal, an active pharmaceutical substance of pharmacopoeial quality was used. When developing methods for testing for “Authenticity,” a reaction with oxalic acid to the zinc cation determined in the composition of acyzole was used. For the quantitative determination of acyzole, the complexometric method was used. The objects of the study were three series of gel samples. Results and discussion. As a result of the research, a method for testing «Authenticity» was developed; it was found that the proposed method is characterized by a negative analytical signal on model mixtures free of the analyte component and placebo, and a positive analytical signal on model mixtures of various compositions containing the analyte component. The validation characteristics of methods for the quantitative determination of acyzole in the gel were studied. positive results were obtained. The proposed methods can be used for inclusion in the regulatory documentation for the developed gel. Conclusion. When assessing the validation characteristics of the proposed methods, it was established that the methods for testing the «Authenticity» and «Quantitative determination» of acyzole in the gel are specific, the methods of quantitative determination are characterized by accuracy and repeatability, a linear dependence in the analytical range of ±20% of the declared amount of acyzole, which allows them to be used for a reliable assessment quality of the developed dental gel.

Development and validation of HPLC-ultraviolet method for quantitative determination of pritelivir in human placental perfusion medium.

A simple and reliable HPLC-ultraviolet (HPLC-UV) method was developed and validated for the quantification of pritelivir in the samples of medium from the experiments utilizing the ex vivo technique of dual perfusion of the human placental lobule. Phenacetin was used as an internal standard (IS) in our HPLC-UV method. Chromatographic separation of pritelivir and phenacetin was achieved on a Waters Symmetry C18 HPLC column (100 × 2.1 mm, 3.5 μm) at ambient temperature (22-25°C). The mobile phase was composed of 50% methanol in deionized water (v/v), the flow rate for isocratic elution was established at 0.25 mL/min, and the detection wavelength for pritelivir and IS was set at 254 nm. Pritelivir and IS were extracted with the protein precipitation method using methanol as a solvent. The calibration curve for pritelivir exhibited linearity (r2 > 0.99) within the concentration range from 0.155 to 6.62 μg/mL. Within- and between-day accuracy ranged from 97% to 110% with relative standard deviation (RSD) values not exceeding 10%. The extraction recovery of pritelivir and IS ranged from 89% to 91% with RSD not exceeding 7%. Pritelivir was stable under the storage and sample handling conditions. This validated HPLC-UV method was utilized to quantify pritelivir in the placental perfusion medium samples, and the resulting concentrations were authenticated with incurred sample reanalysis to confirm the reliability of the method.

Stability-Indicating HPLC Method for Determination of Ibuprofen and Famotidine Degradation Products.

A new stability-indicating high-performance liquid chromatographic method for the quantitative determination of ibuprofen and famotidine degradation products in combined pharmaceutical products was developed and validated. The current aim of this study is to develop a rapid, accurate and robust analytical stability indicating impurity method that can separate ibuprofen, famotidine and their related impurities by using a reversed-phase high-performance liquid chromatography. A Zorbax SB-Phenyl column (4.6 × 150mm2, 5-μm particle size) with mobile phase containing phosphate buffer solution with a pH value of 3.0 and acetonitrile was used. The flow rate was 0.8mL/min and the analytes were detected by UV detector at 265nm. The retention times of ibuprofen and famotidine were 18.43 and 5.14min, respectively. This method was validated to confirm specificity, linearity, sensitivity (limit of detection and limit of quantitation), precision, accuracy, robustness and sample stability according to the International Conference on Harmonization guidelines. Studies have been completed and reported with two active substances in the combined dosage form and seven impurities in total. There is no method in the literature that simultaneously distinguishes and quantitatively analyzes both active substances and degradation products.

Ion Moblity Mass Spectrometry in Multi-omics Studies

Mass spectrometry (MS) as an analytical technique enables the identification and quantitative determination of proteins, metabolites, or lipids in a studied sample. However, this method has limitations regarding the number of molecules that can be identified at a given time. To increase the number of identifications, the application of ion mobility spectrometry (IMS) can be employed. This technique allows the separation of ions based on their mobility while traversing the analyser in a gradient of an electromagnetic field and opposing gas pressure. The separation is performed in conjunction with MS analysis, adding another dimension to the analysis, resulting in a significant improvement in the number of identified compounds and a reduction in noise. Alternatively, while maintaining the same number of identifications, analysis can be performed in a shorter time period. It is crucial to pay special attention to the type of IMS analyser used, as its specific implementation dictates further stages of analysis and ion detection capabilities.

Quantitative determination of lobeglitazone sulfate and glimepiride in combined tablet by robust high‐performance thin layer chromatographic method

AbstractA combination of fixed dose tablet containing 0.5 mg lobeglitazone sulfate (LBZ) and 1 mg glimepiride (GLM) has demonstrated efficacy in enhancing glycemic control in diabetes. The projected work aimed to develop and validate a high‐performance thin‐layer chromatographic (HPTLC) methodology for the precise quantification of both the drugs in tablet formulations. The HPTLC analysis utilized aluminium plates layered with silica gel 60F254, and the solvent system consisted of ethyl acetate, benzene, and hexane (4:3:1 v/v/v) followed by densitometric scanning at 238 nm. The Rf value was found to be 0.68 ± 0.001 for LBZ and 0.48 ± 0.002 for GLM. The methodology exhibited linearity in the range of 100–2000 ng/band for LBZ and 200–4000 ng/band for GLM, with correlation coefficients of 0.9988 and 0.9981, respectively. Exceptional sensitivity was observed, with detection limits of 23.86 ng/band for LBZ and 58.26 ng/band for GLM, along with quantification limits of 72.32 ng/band for LBZ and 176.55 ng/band for GLM. The method demonstrated precision (% relative standard deviation of peak area &lt; 2) and accuracy (recovery between 97% and 102%). The suggested method is suitable for quantifying both the drugs in tablets, making it useful for routine quality control in laboratories.

Simultaneous estimation of mometasone furoate and olopatadine hydrochloride by reversed‐phase high‐performance liquid chromatography

AbstractThe simultaneous determination of Mometasone furoate (MOM) and Olopatadine hydrochloride (OLO) in a combined dose has been developed and validated using a specific, precise, accurate, fast, reliable, and economical high‐performance liquid chromatography technique. Methanol:water:acetonitrile (20:25:55, v/v/v) was used as the mobile phase during the separation. The procedure was performed using a low‐pressure gradient elution on the reversed‐phase Phenomenex C18 column. At 238 nm, separated components were densitometrically measured. The flow rate was fixed at 1.0 mL/min with a continuous run up to 10 min, while the retention time was located near about 3.2 and 6.1 min for OLO and MOM, respectively. The method was validated for Linearity and range, precision, reproducibility, specificity, accuracy, limit of detection, limit of quantification, and robustness as per the International Council for Harmonization Q2(R1) guideline. MOM and OLO regression coefficients (r2) were found to be 0.9994 and 0.9997, over the range of 2.5–15 and 33.25–199.5 µg/mL, respectively. MOM and OLO percentage recoveries were measured to be 99.49 ± 0.14 and 99.98 ± 0.22, respectively. The method can be successfully applied for routine analysis of the quantitative determination of MOM and OLO in a combined dose.

Losartan potassium liquid formulation for paediatric hospital use: development and stability evaluation

ObjectivesThis study aimed to develop a liquid oral formulation containing losartan potassium, an angiotensin II receptor antagonist drug used for its antihypertensive activity, and to perform a preliminary stability assessment...

Assessment of Key Factors Impacting Variability in AAV Vector Genome Titration by Digital PCR

Recombinant adeno-associated virus (rAAV) has emerged as a prominent vector for in vivo gene therapy, owing to its distinct advantages. Accurate determination of the rAAV genome titer is crucial for ensuring the safe and effective administration of clinical doses. The evolution of the rAAV genome titer assay from quantitative PCR (qPCR) to digital PCR (dPCR) has enhanced accuracy and precision, yet practical challenges persist. This study systematically investigated the impact of various operational factors on genome titration in a single-factor manner, aiming to address potential sources of variability in the quantitative determination process. Our findings revealed that a pretreatment procedure without genome extraction exhibits superior precision compared with titration with genome extraction. Additionally, notable variations in titration results across different brands of dPCR instruments were documented, with relative standard deviation (RSD) reaching 23.47% for AAV5 and 11.57% for AAV8. Notably, optimal operations about DNase I digestion were identified; we thought treatment time exceeding 30 min was necessary, and there was no need for thermal inactivation after digestion. And we highlighted that thermal capsid disruption before serial dilution substantially affected AAV genome titers, causing a greater than ten-fold decrease. Conversely, this study found that additive components of dilution buffer are not significant contributors to titration variations. Furthermore, we found that repeated freeze–thaw cycles significantly compromised AAV genome titers. In conclusion, a comprehensive dPCR titration protocol, incorporating insights from these impact factors, was proposed and successfully tested across multiple serotypes of AAV. The results demonstrate acceptable variations, with the RSD consistently below 5.00% for all tested AAV samples. This study provides valuable insights to reduce variability and improve the reproducibility of AAV genome titration using dPCR.

A voltammetric method coupled with chemometrics for determination of a ternary antiparkinson mixture in its dosage form: greenness assessment

An electroanalytical methodology was developed by direct differential pulse voltammetric (DPV) measurement of Levodopa (LD), Carbidopa (CD) and Entacapone (ENT) mixture using bare glassy carbon electrode (GCE) in Britton Robinson (BR) buffer (pH = 2.0). A multivariate calibration model was then applied to the exported preprocessed voltammetric data using partial least square (PLS) as a chemometric tool. Additionally, the model was cross-validated and the number of latent variables (LVs) were determined to produce a reliable model for simultaneous quantitation of the three drugs either in their synthetic mixtures or in their marketed pharmaceutical formulation with high accuracy and precision. Data preprocessing was used to tackle the problem of lacking bi-linearity which is commonly found in electrochemical data. The proposed chemometric model was able to provide fast and reliable technique for quantitative determination of antiparkinson drugs in their dosage forms. This was successfully achieved by utilizing sixteen mixtures as calibration set and nine mixtures as validation set. The percent recoveries for LD, CD and ENT were found to be 100.05% ± 1.28%, 100.04% ± 0.53% and 99.99% ± 1.25%, respectively. The obtained results of the proposed method were statistically compared to those of a previously reported High Performance Liquid Chromatography (HPLC) methodology. Finally, the presented analytical method strongly supports green analytical chemistry regarding the minimization of potentially dangerous chemicals and solvents, as well as reducing energy utilization and waste generation.

Isolation, identification and quantification of flavonoids from the flowers of &lt;i&gt;Staphylea pinnata&lt;/i&gt; L.

Introduction. Search for new plant species containing biologically active substances (hereinafter – BAS) is one of the leading tasks of pharmacognosy as a science. The search for flavonoid glycosides in plant raw materials is especially relevant, since they have anti-inflammatory, antioxidant, immunostimulating, as well as weak fungicidal and bacteriostatic action. Staphylea pinnata L. is an endemic plant of the Caucasus, cultivated not only in Georgia, but also in the Russian Federation in the Northern and Northwestern Caucasus. In foreign literature there are studies of antioxidant, antiproliferative and cytotoxic activity of leaf extracts of several species of S. pinnata L., as well as inhibitory activity of COX-1, COX-2 and LTB4 formation. Meanwhile, no serious Russian-language scientific studies on either the chemical composition or pharmacological action of generative organs of S. pinnata were found in the literature. This work is part of a comprehensive phytochemical study of S. pinnata. The aim of the work is to study the qualitative and quantitative composition of flavonoids in the studied object.Aim. To isolate, identify and quantify flavonoids in flowers and buds of Staphylea pinnata L.Materials and methods. Alcohol-water extracts from dried generative organs of the studied plant were used as analyzed solutions. Solutions were analyzed on a spectrophotometer SF-2000 (LLC "OKB Spectr", Russia) after sample preparation with aluminum chloride and on an HPLC Nexera-i LC-2040 (Shimadzu Corporation, Japan) equipped with a column and sample thermostat, degasser and autosampler using an individually selected elution gradient of the mobile phase (0.1 % orthophosphoric acid/acetonitrile solution). The primary data were processed using LabSolutions Single LC software (Shimadzu Corporation, Japan). Compounds from the flavonoid group were identified by retention times. Detection was carried out using a UV detector with an absorption wavelength of 365 ± 2 nm.Result and discussion. Alcohol-water extracts from flowers and buds of S. pinnata L. were obtained. Quantitative evaluation by spectrophotometry for flavonoid content was carried out. A gradient elution mode for HPLC was selected for simultaneous determination of 7 flavonoid glycosides. These chromatographic conditions allowed the identification and quantification of astragaline, cynaroside, cosmosiin, narcissin and rutin in flowers and buds of Staphylea pinnata L. Flavonoid glycosides: raponticin and kaempferol were not detected.Conclusion. Flavonoid glycosides were isolated from the generative organs of S. pinnata L., a technique for quantitative determination of flavonoid glycosides in alcohol-water extracts was developed, astragalin, cynaroside, cosmosiin, narcissin and rutin were detected and quantified.

Development of a time-resolved immunochromatographic test strip for rapid and quantitative determination of retinol-binding protein 4 in urine.

Urine retinol-binding protein 4 (RBP4) has recently been reported as a novel earlier biomarker of chronic kidney disease (CKD) which is a global public health problem with high morbidity and mortality. Accurate and rapid detection of urine RBP4 is essential for early monitor of impaired kidney function and prevention of CKD progression. In the present study, we developed a time-resolved fluorescence immunochromatographic test strip (TRFIS) for the quantitative and rapid detection of urine RBP4. This TRFIS possessed excellent linearity ranging from 0.024 to 12.50 ng/mL for the detection of urine RBP4, and displayed a good linearity (Y = 239,581 × X + 617,238, R2 = 0.9902), with the lowest visual detection limit of 0.049 ng/mL. This TRFIS allows for quantitative detection of urine RBP4 within 15min and shows high specificity. The intra-batch coefficient of variation (CV) and the inter-batch CV were both < 8%, respectively. Additionally, this TRFIS was applied to detect RBP4 in the urine samples from healthy donors and patients with CKD, and the results of TRFIS could efficiently discern the patients with CKD from the healthy donors. Thedeveloped TRFIS has the characteristics of high sensitivity, high accuracy, and a wide linear range, and is suitable for rapid and quantitative determination of urine RBP4.

THE PROBLEM OF REGULATING FUNGICIDES ON THE SKIN SURFACE FOR OCCUPATIONAL SKIN DISEASE IN AGRICULTURAL WORKERS’ RISK PREDICTION

The aim. To establish the norms of fungicides on the skin surface and predicting the risk of occupational skin pathology in agricultural workers to develop measures to prevent diseases caused by dermal exposure to pesticides. Materials and methods. The natural experiment was performed in accordance with modern requirements (European Food Safety Authority (2022), and the risk assessment was carried out according to the Recommendations (Approved by the Ministry of Health of Ukraine No. 324 issued on 13.05.2009) with different methods of spraying techniques: rod, air blast fan spraying, pre-sowing, aviation, knapsack treatment. 17 series of natural experiments were performed, and the air of the working zone area (n =56) and dermal exposure (n =56) were analyzed for each worker with different pesticide application methods. Quantitative determination of pesticide content was carried out by gas-liquid and high-performance liquid chromatography methods. The results were statistically processed using a package of licensed statistical programs MedStat v.5.2 (Copyright © 2003-2019) and Microsoft® Excel® for Microsoft 365 MSO. Results. It was established that there is pesticide contamination, mainly of the gloves of tank filling operators when preparing working solutions. No contamination of the skin surface was detected; only pesticide residues were present on the surface of the workers’ overalls. A comparison of the exposure dose in case of percutaneous exposure during the performance of technological operations with different methods of processing, dermal equivalents of Acceptable Operator Exposure Level of pesticide to workers’ skin (DE AOEL) and the allowable dermal dose for professional contingents (ADderm) and the hazard coefficients by dermal exposure (HCderm) showed that that dermal exposure during individual technological operations with different processing methods had a reliable difference between processing methods, but there is no difference within one application method. Conclusions. During the comparison of the hazard coefficients for dermal exposure, calculated according to different models, no significant difference was found between the risks calculated according to DE AOEL and ADderm for individual technological operations in various treatment methods, except for the operator who performed knapsack treatment and the risk calculated according to ADderm is significantly lower compared to the DE AOEL risk.

Domestic dogs as environmental sentinel in comparative toxicologic pathology: Assessment of metals and rare earth elements concentrations in healthy and neoplastic mammary glands

Quantification of trace element concentrations in human and animal tissues has acquired great importance in the last few years, considering the pivotal role of these elements in several physiological and pathological processes. Variations in their concentrations appear to have a role in the development and advancement of diseases in both humans and animals, for example, cancer. The purpose of this study was to investigate the concentration of rare earth elements and metals in healthy and neoplastic Formalin-Fixed Paraffin-Embedded (FFPE) mammary gland tissue of dogs. All samples were processed to have a quantitative determination of inorganic elements including metals of known toxicological interest such as Pb, Cd, Tl, As, Hg, the trace elements Mn, Fe, Co, Cu, Zn, Se, and other elements including Cr, V, Mo, Ni, Sb, W, Sn. Moreover, rare earth elements (REEs) (Sc, Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were also investigated. Cu and Mo concentrations in mammary cancerous tissue were greater than those in normal mammary glands (p < 0.05). In non-neoplastic tissue increased concentrations of Cd, Co, Ni, Tl, and V were also reported (p < 0.05). The mammary tissue of healthy individuals had greater concentrations of REEs than the neoplastic mammary glands (p < 0.05). The results of our study confirmed differences in mammary inorganic element concentrations between healthy and neoplastic groups, highlighting the potential relevance of these fluctuations in toxicologic pathology.

MOF-derived multi-"hotspot" 3D Au/MOF-808 (Zr) nanostructures as SERS substrates for the ultrasensitive determination of thiram.

Aconvenient self-assembly methodis proposed for synthesis of 3D Au/MOF-808 (Zr) composite nanostructures with a cerium metal-organic framework loaded with gold nanoparticles. We combine adsorption properties of MOF materials with surface plasmon resonance of noble metals to construct hotspot-dense 3D Au/MOF-808 (Zr) SERS substrates, by using a two-step method of solvothermal and reduction reactions. The results show that optimal SERS substrates are obtained from a volume ratio of gold nanoparticles to MOF-808 (Zr) solution of 4:1 and a self-assembly time of 2h. Rhodamine 6G (R6G) is used as a molecular probe to characterize and analyze SERS properties of substrates of 3D Au/MOF-808 (Zr) prepared under the optimal process conditions, where the substrates are capable to detect R6G concentrations down to 10-10 M with a relative standard deviation of 8.81%. Finally, we applied the SERS substrates of 3D Au/MOF-808 (Zr) to the detection of pesticide thiram, and establish a quantitative determination method. 3D Au/MOF-808 (Zr) provides a sensitive detection of thiram in lake water by SERS with a detection limit of 1.49 × 10-9 M. Application tests show that a SERS enhancement factor of the MOF-based SERS substrates for the detection of thiram can be significantly increased to 5.91 × 105. Thus, the above results indicate that such substrate has high sensitivity, good adsorption, homogeneity, and reproducibility, which can be extended for sensitive detection of pesticide residues in food and environment.

QUANTITATIVE DETERMINATION OF ALUNITE IN ORE AND PRODUCTS OF ITS PROCESSING BY THE DIFFERENTIAL-THERMAL METHOD

The possibility of determining alunite by the derivatographic method according to the area of desulphurization endoeffect on the DTA curve and corresponding to this effect the weight loss on the TG curve has been investigated. It has been proposed to carry out the determination by the calibration curve constructed for standard samples and their area of endoeffect and by the weight loss depending on the content of alunite in the samples, since the dissociation of sulfur bound from 4500C accompanies the whole process. The analysis of samples should be carried out at an intensity of temperature increase of 100C/min, since at an intensity of 300C/min. the peak area increases significantly, and the indicators are not stable. It has been shown that the analyses in an inert medium lead to a twofold loss of sulphur bound, in contrast to the air medium, before desulphurization till the formation of the endoeffect

Studies on Quantitative Determination of Polyphenols in Seven Harvesting Times of Salvia deserta Schang Leaves and its Stability Evaluation

Introduction: Leaves of Salvia deserta Schang at seven harvesting times in the same year were collected as the materials. Method: The polyphenols were determined by the Folin–Ciocaileu method and High-Performance Liquid Chromatography (HPLC) to compare the quality of samples. The stability of polyphenols was studied under different conditions (light, temperature, pH, common additives). objective: The contents of total polyphenols in samples of different growth stages were determined by Folin-Ciocaileu colorimetry. The contents of rosmarinic acid and caffeic acid in samples of different growth stages were determined by HPLC. The stability of polyphenols in Salvia deserta Schang Leaves was investigated by measuring the change of polyphenol retention rate in different media (light, temperature, pH, oxidant, sugar, preservative, salt and citric acid) Results: The results showed that the established method is fast, simple and reliable, which is fully validated in terms of outstanding validation data. High Performance Liquid Chromatography (HPLC) for the determination of total polyphenol content can be quickly and accurately detected, reducing the error of manual determination of the content. The study of polyphenol stability was carried out using a UV spectrophotometer (UV) in order to explore the potential factors affecting polyphenol stability as much as possible and to make the study as scientific and rigorous as possible. The results of quantitative determination showed that there are obvious differences in the content of polyphenols in seven samples. The contents of total polyphenols, rosmarinic acid (RA) and caffeic acid (CA) in the samples harvested in July reached the highest level of 41.37, 26.73 and 1.05 mg/g. Conclusion: The results of the stability assay found that light could damage the stability of polyphenols in samples, especially UV light. Polyphenols are quite sensitive to high temperatures. While polyphenols are less stable when exposed to high alkali conditions and salt treatment, they are much more stable when subjected to low concentrations of redox agents, carbohydrates, and preservatives. The developed methods and stability evaluation provide valuable basis information for quality evaluation and the following use of polyphenols in S. deserta Schang leaves.

Prospects of liquid biopsy in the prognosis and clinical management of gastrointestinal cancers

Gastrointestinal (GI) cancers account for one-fourth of the global cancer incidence and are incriminated to cause one-third of cancer-related deaths. GI cancer includes esophageal, gastric, liver, pancreatic, and colorectal cancers, mostly diagnosed at advanced stages due to a lack of accurate markers for early stages. The invasiveness of diagnostic methods like colonoscopy for solid biopsy reduces patient compliance as it cannot be frequently used to screen patients. Therefore, minimally invasive approaches like liquid biopsy may be explored for screening and early identification of gastrointestinal cancers. Liquid biopsy involves the qualitative and quantitative determination of certain cancer-specific biomarkers in body fluids such as blood, serum, saliva, and urine to predict disease progression, therapeutic tolerance, toxicities, and recurrence by evaluating minimal residual disease and its correlation with other clinical features. In this review, we deliberate upon various tumor-specific cellular and molecular entities such as circulating tumor cells (CTCs), tumor-educated platelets (TEPs), circulating tumor DNA (ctDNA), cell-free DNA (cfDNA), exosomes, and exosome-derived biomolecules and cite recent advances pertaining to their use in predicting disease progression, therapy response, or risk of relapse. We also discuss the technical challenges associated with translating liquid biopsy into clinical settings for various clinical applications in gastrointestinal cancers.

Synchrotron EDXRD strain-temperature measurement during laser welding

Synchrotron EDXRD strain-temperature measurement during laser welding