18,482 results match your criteria validated quantification

Application of a fast and sensitive method for the determination of contaminants of emerging concern in wastewater using a quick, easy, cheap, effective, rugged and safe-based extraction and liquid chromatography coupled to mass spectrometry.

J Chromatogr A 2021 Jul 9;1653:462396. Epub 2021 Jul 9.

CIESOL (Solar Energy Research Center), Joint Centre University of Almeria-CIEMAT, Carretera de Sacramento s/n, Almeria 04120, Spain; Department of Chemistry and Physics, University of Almeria, Carretera de Sacramento s/n, Almeria 04120, Spain.

The inefficiency of wastewater treatment plants (WWTPs) to remove contaminants of emerging concern (CECs) leads to their continuous release to the environment. Consequently, CECs are present at low concentrations in the treated wastewater (TWW), producing unpredicted and unwanted effects on living organisms as they are discharged into water receiving bodies. This work presents a fast and reliable method for the determination of CECs in TWW based on the innovative application of a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for water extraction and determination by sensitive liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS). Read More

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A Predictive Analysis of Wall Stress in Abdominal Aortic Aneurysms Using a Neural Network Model.

J Biomech Eng 2021 Jul 28. Epub 2021 Jul 28.

Department of Mechanical Engineering, University of Texas at San Antonio, San Antonio, TX.

In the present work, we investigated the use of geometric indices to predict patient-specific abdominal aortic aneurysm (AAA) wall stress by means of a novel neural network (NN) modeling approach. We conducted a retrospective review of existing clinical images of two patient groups: 98 asymptomatic and 50 symptomatic AAA. The images were subject to a protocol consisting of image segmentation, processing, volume meshing, finite element modeling, and geometry quantification, from which 53 geometric indices and the spatially averaged wall stress (SAWS) were calculated. Read More

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Microwave Assisted Extraction for Quantification of Microplastics Using Pyrolysis-GC/MS.

Environ Toxicol Chem 2021 Jul 27. Epub 2021 Jul 27.

Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada.

Microplastics (MP) are now recognized as a persistent and global pollutant. To quantitively measure MPs in environmental matrices, several techniques are used - including new methods using Pyrolysis-Gas Chromatography/Mass Spectrometry. In this study, a new extraction method using Microwave-Assisted Extraction (MAE) combined with Py-GC/MS was developed to extract and quantify a wide range of plastic polymers and validated using different environmental matrices. Read More

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Identification and Quantification of Bovine Digital Dermatitis-Associated Microbiota across Lesion Stages in Feedlot Beef Cattle.

mSystems 2021 Jul 27:e0070821. Epub 2021 Jul 27.

Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgarygrid.22072.35, Calgary, Alberta, Canada.

Bovine digital dermatitis (DD) is a skin disorder that is a significant cause of infectious lameness in cattle around the world. However, very little is known about the etiopathogenesis of the disease and the microbiota associated with DD in beef cattle. In this study, we provide a comprehensive characterization of DD and healthy skin microbiota of feedlot beef cattle. Read More

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Phase-contrast acceleration mapping with synchronized encoding.

Magn Reson Med 2021 Jul 27. Epub 2021 Jul 27.

Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.

Purpose: To develop a phase-contrast (PC) -based method for direct and unbiased quantification of the acceleration vector field by synchronization of the spatial and acceleration encoding time points. The proposed method explicitly aims at in-vitro applications, requiring high measurement accuracy, as well as the validation of clinically relevant acceleration-encoded sequences.

Methods: A velocity-encoded sequence with synchronized encoding (SYNC SPI) was modified to allow direct acceleration mapping by replacing the bipolar encoding gradients with tripolar gradient waveforms. Read More

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A study of the effect of working parameters and validation of SEM/EDS method for determination of elemental composition of commonly encountered GSR samples in shooting events in Kosovo.

J Forensic Sci 2021 Jul 23. Epub 2021 Jul 23.

Analytical Chemistry Department, University of Chemical Technology and Metallurgy, Sofia, Bulgaria.

Reliability of forensic evidences for presence of inorganic gunshot residue (iGSR) on a given surface strongly depends on the performance of scanning electron microscopy/energy dispersive X-ray spectrometry (SEM-EDS) method. This article presents the results from a study of the effect of SEM/EDS working parameters on the method performance and quality of iGSR data, as well as a development of a database of iGSR encountered in R Kosovo. The optimal working parameters of SEM/EDS were established by one-variable-at-a-time approach and the method was validated according to ASTM1588-10. Read More

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Highly sensitive analytical method for the accurate determination of 5-methyltetrahydrofolic acid monoglutamate in various volumes of human plasma using isotope dilution ultra-high performance liquid chromatography-mass spectrometry.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Apr 24;1179:122725. Epub 2021 Apr 24.

Division of Chemical and Medical Metrology, Korea Research Institute of Standards and Science, Yuseong, Daejeon 34113, Republic of Korea.

One predominant and bioactive folate vitamer circulating in the blood is 5-methyltetrahydrofolate (5-Me-THF). In this study, a method for the accurate determination of 5-Me-THF in human plasma samples of various volumes was established using isotope dilution ultra-high performance liquid chromatography-mass spectrometry (ID-UPLC-MS). For this purpose, 500 μL of homogeneous human plasma was initially employed, and the 5-Me-THF and the C-5-Me-THF standard solutions prepared using 1% ascorbic acid in water gave the calibration solution and spiking sample. Read More

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Model-based X-ray Induced Acoustic Computed Tomography.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 Jul 26;PP. Epub 2021 Jul 26.

X-ray induced acoustic computed tomography (XACT) provides X-ray absorption based contrast with acoustic detection. For its clinical translation, XACT imaging often has a limited field of view. This can result in image artifacts and overall loss of quantification accuracy. Read More

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Simultaneous Determination of 25 Ginsenosides by UPLC-HRMS via Quantitative Analysis of Multicomponents by Single Marker.

Int J Anal Chem 2021 1;2021:9986793. Epub 2021 Jul 1.

School of Life Sciences, Northeast Normal University, Changchun 130024, China.

A method using UPLC-HRMS has been developed for a rapid, simultaneous qualitative and quantitative analysis of twenty-five ginsenosides. Chromatographic separation was achieved on a C analytical column with an elution gradient comprising 0.1% aqueous formate/acetonitrile as the mobile phase. Read More

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Quantification and discovery of quality control chemical markers for Ba-Bao-Dan by UPLC-MS/MS combined with chemometrics.

J Pharm Biomed Anal 2021 Jul 21;204:114273. Epub 2021 Jul 21.

College of Pharmacy, Fujian Key Laboratory of Chinese Materia Medica, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China. Electronic address:

Ba-Bao-Dan (BBD) is a well-known Traditional Chinese medicine (TCM) prescription in China. It was first formulated in approximately 1555 AD. As one of the National Protected TCM, it is widely used to treat jaundice, viral hepatitis, cholecystitis, acute urinary tract infection, cancer, and other diseases. Read More

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Development & validation of LC-MS/MS assay for 5-amino-1-methyl quinolinium in rat plasma: Application to pharmacokinetic and oral bioavailability studies.

J Pharm Biomed Anal 2021 Jul 8;204:114255. Epub 2021 Jul 8.

Department of Pharmaceutical Sciences, Texas Southern University, Houston, TX, 77004, United States. Electronic address:

5-Amino-1-methyl quinolinium (5-AMQ) is a potent Nicotinamide N-methyl transferase (NNMT) inhibitor. NNMT is an enzyme that catalyzes the N-methylation of the endogenous substrate nicotinamide, as well as exogenous xenobiotics. NNMT is fundamental to cellular metabolism; NNMT is overexpressed in select tissues (e. Read More

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Development of an LC-MS/MS method for quantification of 3-chloro-L-tyrosine as a candidate marker of chlorine poisoning.

Leg Med (Tokyo) 2021 Jul 9;53:101939. Epub 2021 Jul 9.

Department of Legal Medicine, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi-ku, Tokyo 173-8605, Japan.

A simple and sensitive liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for the determination of 3-chloro-L-tyrosine (Cl-Tyr) was developed and validated. For sample preparation, 50 μL of the body fluids or tissue extracts were processed by protein precipitation followed by the derivatization with dansyl chloride. The calibration curve was linear over the concentration range of 2. Read More

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Motion-based camera localization system in colonoscopy videos.

Med Image Anal 2021 Jul 15;73:102180. Epub 2021 Jul 15.

Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA; Michigan Institute for Data Science, University of Michigan, Ann Arbor, MI, USA; Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, MI, USA; Department of Emergency Medicine, University of Michigan, Ann Arbor, MI, USA. Electronic address:

Optical colonoscopy is an essential diagnostic and prognostic tool for many gastrointestinal diseases, including cancer screening and staging, intestinal bleeding, diarrhea, abdominal symptom evaluation, and inflammatory bowel disease assessment. However, the evaluation, classification, and quantification of findings from colonoscopy are subject to inter-observer variation. Automated assessment of colonoscopy is of interest considering the subjectivity present in qualitative human interpretations of colonoscopy findings. Read More

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Validated Simultaneous Gradient Ultra-Performance Liquid Chromatographic Quantification of Some Proton Pump Inhibitor Drug Residues in Saudi Pharmaceutical Industrial Wastewater.

Molecules 2021 Jul 19;26(14). Epub 2021 Jul 19.

Pharmaceutical Chemistry Department, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj 11942, Saudi Arabia.

Monitoring and quantification of active pharmaceutical ingredients (APIs) in the environment constitute important and challenging tasks, as they are directly associated with human health. Three commonly used proton pump inhibitors (PPIs), namely, omeprazole sodium (OMP), pantoprazole sodium (PNT), and lansoprazole sodium (LNZ) are well separated and quantified using ultra-performance liquid chromatography (UPLC) in pharmaceutical industrial wastewater. The separation of the studied drugs was performed on a stationary phase with a Waters column (100 × 2. Read More

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Validation of a Simple HPLC-Based Method for Lysine Quantification for Ruminant Nutrition.

Molecules 2021 Jul 9;26(14). Epub 2021 Jul 9.

LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal.

Robust and selective quantification methods are required to better analyze feed supplementation effectiveness with specific amino acids. In this work, a reversed-phase high-performance liquid chromatography method with fluorescence detection is proposed and validated for lysine quantification, one of the most limiting amino acids in ruminant nutrition and essential towards milk production. To assess and widen method applicability, different matrices were considered: namely LiCO buffer (the chosen standard reaction buffer), phosphate buffer solution (to mimic media in cellular studies), and rumen inoculum. Read More

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Quantification of advanced glycation end products and amino acid cross-links in foods by high-resolution mass spectrometry: Applicability of acid hydrolysis.

Food Chem 2021 Jul 15;366:130601. Epub 2021 Jul 15.

Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark. Electronic address:

An analytical method was developed and validated for simultaneous identification and quantification of advanced glycation end products (AGEs), amino acid cross-links, lysine and arginine in foodstuffs based on acid hydrolysis, hydrophilic interaction chromatography and high-resolution mass spectrometry. The method proved to be sensitive, reproducible and accurate for furosine, N-Ɛ-(carboxymethyl)lysine, N-Ɛ-(carboxyethyl)lysine, methylglyoxal and glyoxal-derived hydroimidazolones (MG-H and GO-H isomers, respectively), glyoxal lysine dimer, lysinoalanine, lanthionine, lysine and arginine. LOD and LOQ values in water were found to be 0. Read More

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Green spectrofluorimetric assay of dantrolene sodium via reduction method: application to content uniformity testing.

R Soc Open Sci 2021 Jul 14;8(7):210562. Epub 2021 Jul 14.

Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Mansoura University, 35516 Mansoura, Egypt.

Green analysis has turned out to be of a great value in all areas, including pharmaceutical analysis. Thus, it is extremely important to consider the environmental influence of each step in developing any analysis technique. The present work illustrates a validated, simple and green spectrofluorimetric method for the analysis of dantrolene sodium (DAN). Read More

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HPLC Method Validated for Quantification of Fluconazole Co-Encapsulated with Propolis Within Chitosan Nanoparticles.

Indian J Microbiol 2021 Sep 16;61(3):364-369. Epub 2021 Jun 16.

Laboratory of Nano & Biotechnology, Instituto de Patologia Tropical E Saúde Pública, Universidade Federal de Goiás, Rua 235, s/ n, Setor Universitário, Goiânia, GO Brazil.

Considering the cases of fungal resistance to classic antifungals, it is necessary to develop more efficient and innovative therapies capable of reversing this situation. Fluconazole is an antifungal frequently used in the treatment of mycosis and some fungi developed resistance to its mechanism of action. In this work, fluconazole and green propolis were co-encapsulated in chitosan nanoparticles to be explored in order to promote a synergistic effect to enhance its therapeutic efficacy. Read More

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September 2021

Non-targeted analysis by DLLME-GC-MS for the monitoring of pollutants in the Mar Menor lagoon.

Chemosphere 2021 Jul 17;286(Pt 1):131588. Epub 2021 Jul 17.

Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, E-30100, Murcia, Spain. Electronic address:

Non-targeted analysis for the monitoring of organic pollutants resulting from agricultural and industrial practices, plastics and pharmaceutical products of seawater from the Mar Menor lagoon (SE Spain) is proposed using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-mass spectrometry (GC-MS). Initially, a home-made MS database including 118 environmental organic pollutants, whose presence in different ecosystems has already been reported, was created. The analytical method was applied for the analysis of 42 samples and a total of 18 pollutants were detected and identified. Read More

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Determination of Alternaria toxins in tomato, wheat and sunflower seeds by SPE and LC-MS/MS - a method validation through a collaborative trial.

J AOAC Int 2021 Jul 22. Epub 2021 Jul 22.

European Commission, Joint Research Centre (JRC), Geel, Belgium.

Background: Alternaria toxins are ubiquitous contaminants in highly consumed food products. Therefore, they are candidates to be regulated by EU legislation. In this context the availability of reliable analytical methods is a keystone both for protecting the health of the citizens and the smooth functioning of the European market. Read More

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A novel method for the quantification of anlotinib in human plasma using two-dimensional liquid chromatography.

Biomed Chromatogr 2021 Jul 22:e5218. Epub 2021 Jul 22.

Shandong Cancer Hospital and Institute Shandong First Medical University and Shandong Academy of Medical Sciences.

A simple, efficient and stable detection method of two-dimensional liquid chromatography(2D-LC) was established and validated for the determination of anlotinib in human plasma. The 2D-LC system comprises a first-dimensional column (LC1), an intermediate transfer column and a second-dimensional column (LC2). With simple protein precipitation treatment, the samples were processed directly for detecting. Read More

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Quantification of fentanyl analogs in oral fluid using LC-QTOF-MS.

J Forensic Sci 2021 Jul 20. Epub 2021 Jul 20.

Department of Forensic Science, College of Criminal Justice, Sam Houston State University, Huntsville, TX, USA.

Oral fluid is a valuable alternative matrix for forensic toxicologists due to ease of observed collection, limited biohazardous exposure, and indications of recent drug use. Limited information is available for fentanyl analog prevalence, interpretation, or analysis in oral fluid. With increasing numbers of fentanyl-related driving under the influence of drug (DUID) cases appearing in the United States, the development of detection methods is critical. Read More

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Towards nanovesicle-based disease diagnostics: a rapid single-step exosome assay within one hour through immunomagnetic extraction and nanophotonic label-free detection.

Lab Chip 2021 Jul 21. Epub 2021 Jul 21.

Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA. and Microelectronics Research Centre, Iowa State University, Ames, Iowa 50011, USA and Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, USA.

Exosomes have been considered as high-quality biomarkers for disease diagnosis, as they are secreted by cells into extracellular environments as nanovesicles with rich and unique molecular information, and can be isolated and enriched from clinical samples. However, most existing exosome assays, to date, require time-consuming isolation and purification procedures; the detection specificity and sensitivity are also in need of improvement for the realization of exosome-based disease diagnostics. This paper reports a unique exosome assay technology that enables completing both magnetic nanoparticle (MNP)-based exosome extraction and high-sensitivity photonic crystal (PC)-based label-free exosome detection in a single miniature vessel within one hour, while providing an improved sensitivity and selectivity. Read More

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Development of a novel in vitro primary human monocyte-derived macrophage model to study reactivation of HIV-1 transcription.

J Virol 2021 Jul 21:JVI0022721. Epub 2021 Jul 21.

Department of Infectious Diseases, Monash University, Melbourne, Australia.

Latent HIV reservoirs persist in people living with HIV despite effective antiretroviral therapy and contribute to rebound viremia upon treatment interruption. Macrophages are an important reservoir cell-type, but analysis of agents that modulate latency in macrophages is limited by lack of appropriate models. We therefore generated an experimental system to investigate this by purifying non-productively-infected human monocyte-derived macrophages (MDM) following infection with an M-tropic EGFP reporter HIV clone, and quantified activation of HIV transcription using live-cell fluorescence microscopy. Read More

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Development of UV-Visible spectrophotometric methods for the quantitative and in silico studies for cilazapril optimized by response surface methodology.

Drug Dev Ind Pharm 2021 Jul 21:1-43. Epub 2021 Jul 21.

Analytical Chemistry Section, Department of Chemistry, Aligarh Muslim University, Aligarh, U.P. 202002, India.

For cilazapril, analytical methods based on donor-acceptor phenomenon that are simple, rapid with broad linear dynamic range for the quantification of drug are not available in the literature. Considering the requirement for the methods, in this study, two economic, potent analytical methods based on the complexation of cilazapril with 𝛑-acceptors, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,5-Dichloro-3,6-dihydroxy-p-benzoquinone (CA) were developed, validated and studied spectrophotometrically. Various analytical data were discussed. Read More

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An integrative approach to define chemical exposure threshold limits for endangered sea turtles.

J Hazard Mater 2021 Jul 4;420:126512. Epub 2021 Jul 4.

Australian Rivers Institute, School of Environment and Science, Griffith University, Gold Coast, Australia.

Environmental contaminants pose serious health threats to marine megafauna species, yet methods defining exposure threshold limits are lacking. Here, a three-pillar chemical risk assessment framework is presented based on (1) species- and chemical-specific lifetime bioaccumulation modelling, (2) non-destructive in vitro and in vivo toxicity threshold assessment, and (3) chemical risk quantification. We used the effects of cadmium (Cd) in green sea turtles (Chelonia mydas) as a proof of concept to evaluate the quantitative mechanistic modelling approach. Read More

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Differentiating iron-loading anemias using a newly developed and analytically validated ELISA for human serum erythroferrone.

PLoS One 2021 20;16(7):e0254851. Epub 2021 Jul 20.

Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.

Erythroferrone (ERFE), the erythroid regulator of iron metabolism, inhibits hepcidin to increase iron availability for erythropoiesis. ERFE plays a pathological role during ineffective erythropoiesis as occurs in X-linked sideroblastic anemia (XLSA) and β-thalassemia. Its measurement might serve as an indicator of severity for these diseases. Read More

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Signal Separated Quantification of γ-Hydroxybutyrate With Liquid Chromatography-Tandem Mass Spectrometry in Human Urine and Serum as an Improvement of the Analyte Adduct Ion Based Quantification.

J Anal Toxicol 2021 Jul 20. Epub 2021 Jul 20.

Institute of Legal Medicine, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.

The aim of the work was the development and validation of an LC-MS/MS γ-hydroxybutyrate (GHB) quantification method in urine and human serum by the use of the analyte adduct ion formation strategy. A combined detection with a conventional precursor ion in the negative electrospray mode and additionally GHB adduct ions with both sodium acetate and lithium acetate was in focus. Therefore GHB quantification based on separated MS/MS signals. Read More

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BrcaSeg: A Deep Learning Approach for Tissue Quantification and Genomic Correlations of Histopathological Images.

Genomics Proteomics Bioinformatics 2021 Jul 16. Epub 2021 Jul 16.

Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Biostatistics and Health Data Science, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Regenstrief Institute, Indianapolis, IN 46202, USA. Electronic address:

Epithelial and stromal tissues are components of the tumor microenvironment and play a major role in tumor initiation and progression. Distinguishing stroma from epithelial tissues is critically important for spatial characterization of the tumor microenvironment. We propose BrcaSeg, an image analysis pipeline based on a convolutional neural network (CNN) model to classify epithelial and stromal regions in whole-slide hematoxylin and eosin (H&E) stained histopathological images. Read More

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Size-exclusion chromatography selective cleanup of aflatoxins in oilseeds followed by HPLC determination to assess the potential health risk.

Toxicon 2021 Jul 17;200:110-117. Epub 2021 Jul 17.

Environment and Bio-Agriculture Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt.

Aflatoxins (AFs) are one of the most harmful carcinogenic natural toxins that affect food. Crops containing reasonably high oil content may be affected by Aspergillus species and consequently by AF contamination. In this study, a proposed testing method for AF detection in oilseed was developed, validated, and used for a market survey to assess the probabilistic risk exposure caused by consuming contaminated oilseeds including corn, sunflower seed, and soybean. Read More

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