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https://www.readbyqxmd.com/read/29156792/liquid-biopsy-in-colon-cancer-comparison-of-different-circulating-dna-extraction-systems-following-absolute-quantification-of-kras-mutations-using-intplex-allele-specific-pcr
#1
Vera Kloten, Nadine Rüchel, Nadina Ortiz Brüchle, Janina Gasthaus, Nils Freudenmacher, Florian Steib, Jolein Mijnes, Julian Eschenbruch, Marcel Binnebösel, Ruth Knüchel, Edgar Dahl
Non-invasive molecular analysis of circulating tumor DNA (ctDNA) is a promising application in personalized cancer management, although there is still much to learn about the biological characteristics of ctDNA. The present study compared absolute amounts of KRAS mutated ctDNA and total circulating cell-free DNA (cfDNA) in colorectal cancer (CRC) patients (n=50) from various stages and healthy controls (n=8) by Intplex allele-specific and digital droplet PCR. In addition, the impact of two prominent extraction techniques (silica-based membrane vs...
October 17, 2017: Oncotarget
https://www.readbyqxmd.com/read/29156625/gene-based-pathogen-detection-can-we-use-qpcr-to-predict-the-outcome-of-diagnostic-metagenomics
#2
Sandra Christine Andersen, Mette Sofie Rousing Fachmann, Kristoffer Kiil, Eva Møller Nielsen, Jeffrey Hoorfar
In microbial food safety, molecular methods such as quantitative PCR (qPCR) and next-generation sequencing (NGS) of bacterial isolates can potentially be replaced by diagnostic shotgun metagenomics. However, the methods for pre-analytical sample preparation are often optimized for qPCR, and do not necessarily perform equally well for qPCR and sequencing. The present study investigates, through screening of methods, whether qPCR can be used as an indicator for the optimization of sample preparation for NGS-based shotgun metagenomics with a diagnostic focus...
November 20, 2017: Genes
https://www.readbyqxmd.com/read/29156618/optimized-lateral-flow-immunoassay-reader-for-the-detection-of-infectious-diseases-in-developing-countries
#3
Evdokia Pilavaki, Andreas Demosthenous
Detection and control of infectious diseases is a major problem, especially in developing countries. Lateral flow immunoassays can be used with great success for the detection of infectious diseases. However, for the quantification of their results an electronic reader is required. This paper presents an optimized handheld electronic reader for developing countries. It features a potentially low-cost, low-power, battery-operated device with no added optical accessories. The operation of this proof of concept device is based on measuring the reflected light from the lateral flow immunoassay and translating it into the concentration of the specific analyte of interest...
November 20, 2017: Sensors
https://www.readbyqxmd.com/read/29156577/magnetic-flux-distribution-of-linear-machines-with-novel-three-dimensional-hybrid-magnet-arrays
#4
Nan Yao, Liang Yan, Tianyi Wang, Shaoping Wang
The objective of this paper is to propose a novel tubular linear machine with hybrid permanent magnet arrays and multiple movers, which could be employed for either actuation or sensing technology. The hybrid magnet array produces flux distribution on both sides of windings, and thus helps to increase the signal strength in the windings. The multiple movers are important for airspace technology, because they can improve the system's redundancy and reliability. The proposed design concept is presented, and the governing equations are obtained based on source free property and Maxwell equations...
November 18, 2017: Sensors
https://www.readbyqxmd.com/read/29156554/a-high-performance-liquid-chromatography-assay-method-for-the-determination-of-lidocaine-in-human-serum
#5
Hamdah M Al Nebaihi, Matthew Primrose, James S Green, Dion R Brocks
Here we report on the development of a selective and sensitive high-performance liquid chromatographic method for the determination of lidocaine in human serum. The extraction of lidocaine and procainamide (internal standard) from serum (0.25 mL) was achieved using diethyl ether under alkaline conditions. After liquid-liquid extraction, the separation of analytes was accomplished using reverse phase extraction. The mobile phase, a combination of acetonitrile and monobasic potassium phosphate, was pumped isocratically through a C18 analytical column...
November 18, 2017: Pharmaceutics
https://www.readbyqxmd.com/read/29156408/label-free-electrochemical-dna-biosensor-for-guanine-and-adenine-by-ds-dna-poly-l-cysteine-fe3o4-nanoparticles-graphene-oxide-nanocomposite-modified-electrode
#6
Majid Arvand, Mona Sanayeei, Shiva Hemmati
In this study, we aim to design a simple and effective electrochemical DNA biosensor based on a carbon paste electrode modified with ds-DNA/poly(L-cysteine)/Fe3O4 nanoparticles-graphene oxide (ds-DNA/p(L-Cys)/Fe3O4 NPs-GO/CPE) for sensitive detection of adenine (A) and guanine (G). The electrocatalytic oxidation of A and G on the electrode was explored by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). This sensor shows separated and well-defined peaks for A and G, by which one can determine these biological bases individually or simultaneously...
November 7, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29156407/ultrasensitive-detection-of-prostate-specific-antigen-by-electrochemical-aptasensor-using-enzyme-free-recycling-amplification-via-target-induced-catalytic-hairpin-assembly
#7
Juncai Zhao, Zhanfang Ma
Based on the target-induced catalytic hairpin assembly and bimetallic catalyst, the enzyme-free recycling amplification strategy for sensitive detection of prostate specific antigen (PSA) has been designed. The aptamer and its complementary DNA (C-apt) are modified on the magnetic particles. The aptamer-PSA binding event can release the C-apt that triggers the catalytic assembly between hairpin capture DNA and hairpin help DNA. Then the catalytic hairpin assembly leads to cyclic reuse the C-apt and the generation of many opened hairpin capture DNA, which can associate with the prepared Au/Pt-polymethylene blue (PMB) probes to yield electrochemical signal...
November 15, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29156362/test-anxiety-effects-predictors-and-correlates-a-30-year-meta-analytic-review
#8
REVIEW
Nathaniel von der Embse, Dane Jester, Devlina Roy, James Post
BACKGROUND AND OBJECTIVES: Since the 1988 publication of Hembree's seminal meta-analysis on test anxiety, much has changed in the theoretical conceptualization of test anxiety, as well as the influences on test performance. The present study examined the influence of test anxiety on a variety of educational outcomes, in addition to demographic and intrapersonal correlates. DESIGN AND METHODS: Results of 238 studies from 1988 to the present, were synthesized via a meta-analytic framework to explicate predictors, correlates, and relationships with the test anxiety construct...
November 13, 2017: Journal of Affective Disorders
https://www.readbyqxmd.com/read/29156274/determination-of-2-6-di-tert-butyl-hydroxytoluene-and-its-transformation-products-in-indoor-dust-and-sediment-by-gas-chromatography-mass-spectrometry-coupled-with-precolumn-derivatization
#9
Ruirui Zhang, Chao Li, Yunzi Li, Xinyi Cui, Lena Q Ma
We developed an analytical method to simultaneously determine 2,6-di-tert-butyl-hydroxytoluene (BHT) and its four transformation products in indoor dust and sediment samples. BHT, 2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione (BHT-Q), and 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO) were measured by gas chromatography-mass spectrometry (GC-MS) after ultrasonic extraction with hexane/dichloromethane (1:3), while 2,6-di-tert-butyl-4-(hydroxymethyl) phenol (BHT-OH) and 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH) were derivatized using N, O-bis (trimethylsilyl) trifluoroacetamide before GC-MS analysis...
November 17, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29156265/occurrence-and-fate-of-most-prescribed-antibiotics-in-different-water-environments-of-tehran-iran
#10
Roya Mirzaei, Masud Yunesian, Simin Nasseri, Mitra Gholami, Esfandiyar Jalilzadeh, Shahram Shoeibi, Alireza Mesdaghinia
The presence of most prescribed antibiotic compounds from four therapeutic classes (β-lactam, cephalosporins, macrolides, fluoroquinolones) were studied at two full-scale WWTPs, two rivers, thirteen groundwater resources, and five water treatment plants in Tehran. Analytical methodology was based on high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. Samples were collected at 33 sample locations on three sampling periods over four months from June to August 2016. None of the target antibiotics were detected in groundwater resources and water treatment plants, while seven out of nine target antibiotics were analyzed in two studied river waters as well as the influent and effluent of wastewater treatment plants at concentrations ranging from <LOQ to 926...
November 16, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29156137/biologically-consistent-annotation-of-metabolomics-data
#11
Nicholas Alden, Smitha Krishnan, Vladimir Porokhin, Ravali Raju, Kyle McElearney, Alan Gilbert, Kyongbum Lee
Annotation of metabolites remains a major challenge in liquid chromatography-mass spectrometry (LC-MS) based untargeted metabolomics. The current gold standard for metabolite identification is to match the detected feature with an authentic standard analyzed on the same equipment and using the same method as the experimental samples. However, there are substantial practical challenges in applying this approach to large datasets. One widely used annotation approach is to search spectral libraries in reference databases for matching metabolites; however, this approach is limited by the incomplete coverage of these libraries...
November 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29156125/validating-coarse-grained-voltage-activation-model-by-comparing-the-performance-to-the-results-of-mc-simulations
#12
Myungjin Lee, Vesselin Kolev, Arieh Warshel
Simulating the nature of voltage activated systems is a problem of major current interest, covering the action of voltage gated ion channels to energy storage batteries. However, fully microscopic converging molecular simulations of external voltage effects present a major challenge and macroscopic models are associated with major uncertainties about the dielectric treatment and the underlying physical basis. Recently we developed a coarse grained (CG) model that represents explicit the electrodes, the electrolytes and the membrane / protein system...
November 20, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29155919/neonatal-outcomes-in-a-medicaid-population-with-opioid-dependence
#13
Susan B Brogly, Sonia Hernández-Diaz, Emily Regan, Ela Fadli, Kristen A Hahn, Martha M Werler
Confounding may account for the apparent improved infant outcomes after prenatal exposure to buprenorphine versus methadone. We used Massachusetts Medicaid Analytic eXtract (MAX) data to identify a cohort of opioid dependent mother-infant pairs (2006-2011) supplemented with confounder data from an external Boston cohort (2015-2016). Associations between prenatal buprenorphine versus methadone exposure and infant outcomes in the MAX Cohort were adjusted for measured MAX confounders, and unmeasured confounders with bias analysis using External Cohort data...
November 16, 2017: American Journal of Epidemiology
https://www.readbyqxmd.com/read/29155892/derivation-and-application-of-an-analytical-rock-displacement-solution-on-rectangular-cavern-wall-using-the-inverse-mapping-method
#14
Mingzhong Gao, Bin Yu, Zhiqiang Qiu, Xiangang Yin, Shengwei Li, Qiang Liu
Rectangular caverns are increasingly used in underground engineering projects, the failure mechanism of rectangular cavern wall rock is significantly different as a result of the cross-sectional shape and variations in wall stress distributions. However, the conventional computational method always results in a long-winded computational process and multiple displacement solutions of internal rectangular wall rock. This paper uses a Laurent series complex method to obtain a mapping function expression based on complex variable function theory and conformal transformation...
2017: PloS One
https://www.readbyqxmd.com/read/29155848/an-electronic-health-record-based-model-predicts-statin-adherence-ldl-cholesterol-and-cardiovascular-disease-in-the-united-states-military-health-system
#15
Joseph E Lucas, Taylor C Bazemore, Celan Alo, Patrick B Monahan, Deepak Voora
HMG-CoA reductase inhibitors (or "statins") are important and commonly used medications to lower cholesterol and prevent cardiovascular disease. Nearly half of patients stop taking statin medications one year after they are prescribed leading to higher cholesterol, increased cardiovascular risk, and costs due to excess hospitalizations. Identifying which patients are at highest risk for not adhering to long-term statin therapy is an important step towards individualizing interventions to improve adherence. Electronic health records (EHR) are an increasingly common source of data that are challenging to analyze but have potential for generating more accurate predictions of disease risk...
2017: PloS One
https://www.readbyqxmd.com/read/29155764/multiplex-cytokine-profiling-of-stimulated-mouse-splenocytes-using-a-cytometric-bead-based-immunoassay-platform
#16
Jason S Lehmann, Amy Zhao, Binggang Sun, Weiping Jiang, Shaoquan Ji
Bead-based immunoassays employ the same basic principle as sandwich immunoassays. Capture beads, which can be differentiated by size and internal allophycocyanin (APC) fluorescence intensity, are conjugated to antibodies specific to a particular analyte. Next, a selected panel of defined capture bead sets is incubated with a biological sample containing target analytes specific to the capture antibodies. A biotinylated detection antibody cocktail is added, which leads to the formation of capture bead-analyte-detection antibody sandwiches...
November 9, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29155727/microrna-based-liquid-biopsy-the-experience-of-the-plasma-mirna-signature-classifier-msc-for-lung-cancer-screening
#17
Mavis Mensah, Cristina Borzi, Carla Verri, Paola Suatoni, Davide Conte, Ugo Pastorino, Fortunato Orazio, Gabriella Sozzi, Mattia Boeri
The development of a minimally invasive test, such as liquid biopsy, for early lung cancer detection in its preclinical phase is crucial to improve the outcome of this deadly disease. MicroRNAs (miRNAs) are tissue specific, small, non-coding RNAs regulating gene expression, which may act as extracellular messengers of biological signals derived from the cross-talk between the tumor and its surrounding microenvironment. They could thus represent ideal candidates for early detection of lung cancer. In this work, a methodological workflow for the prospective validation of a circulating miRNA test using custom made microfluidic cards and quantitative Real-Time PCR in plasma samples of volunteers enrolled in a lung cancer screening trial is proposed...
October 26, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29155604/modelling-evolutionary-algorithms-with-stochastic-differential-equations
#18
Jorge Pérez Heredia
There has been renewed interest in modelling the behaviour of evolutionary algorithms (EAs) by more traditional mathematical objects, such as ordinary differential equations or Markov chains. The advantage is that the analysis becomes greatly facilitated due to the existence of well established methods. However, this typically comes at the cost of disregarding information about the process. Here, we introduce the use of stochastic differential equations (SDEs) for the study of EAs. SDEs can produce simple analytical results for the dynamics of stochastic processes, unlike Markov chains which can produce rigorous but unwieldy expressions about the dynamics...
November 20, 2017: Evolutionary Computation
https://www.readbyqxmd.com/read/29155574/mechanism-of-formation-of-chlorinated-pyrene-during-combustion-of-polyvinyl-chloride
#19
Yuichi Miyake, Masahiro Tokumura, Qi Wang, Takashi Amagai, Yuichi Horii, Kurunthachalam Kannan
Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are an emerging class of environmental contaminants, but the sources of ClPAHs in the environment are not well known. In this study, we developed a kinetic model describing the chlorination of PAHs to observe the mechanism of formation of ClPAHs during the combustion of organic waste containing chlorinated compounds and/or chloride in an incinerator. Pyrene (Pyr) and polyvinyl chloride (PVC) were selected as a model PAH and a model organic substrate, respectively...
November 20, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29155565/an-integrated-hot-stage-microscope-direct-analysis-in-real-time-mass-spectrometry-system-for-studying-the-thermal-behavior-of-materials
#20
Gage P Ashton, Lindsay P Harding, Gareth M B Parkes
This paper describes a new analytical instrument that combines a precisely temperature-controlled hot-stage with digital microscopy and Direct Analysis in Real-Time mass spectrometry (DART-MS) detection. The novelty of the instrument lies in its ability to monitor processes as a function of temperature through the simultaneous recording of images, quantitative color changes and mass spectra. The capability of the instrument was demonstrated through successful application to four very varied systems including profiling an organic reaction, decomposition of silicone polymers and the desorption of rhodamine B from an alumina surface...
November 20, 2017: Analytical Chemistry
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