journal
MENU ▼
Read by QxMD icon Read
search

Analytical Methods: Advancing Methods and Applications

journal
https://www.readbyqxmd.com/read/28966665/si-traceable-determination-of-arsenic-species-in-kelp-thallus-laminariae
#1
Lee L Yu, Rachel C Stanoyevitch, Rolf Zeisler
A dietary supplement, kelp contains a significant amount of arsenic that is mostly arsenosugars. The determination of arsenosugars is difficult due to a lack of arsenosugar calibration standard, because arsenosugar compounds are not commercially available. This work reports the determination of arsenicals in a kelp extract with traceability to the International System of Units (SI). The hydrophilic fraction of arsenicals was reproducibly extracted from a candidate Standard Reference Material (SRM) 3232 Kelp Powder (Thallus Laminariae) in development at the National Institute of Standards and Technology (NIST)...
August 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28824713/recent-liquid-chromatographic-approaches-and-developments-for-the-separation-and-purification-of-carbohydrates
#2
Gabe Nagy, Tianyuan Peng, Nicola L B Pohl
Carbohydate purification remains a bottleneck in securing analytical standards from natural sources or by chemical or enzymatic synthesis. This review highlights the scope and remaining limitations of recent approaches and methods development in liquid chromatography for robust and higher-throughput carbohydrate separation and isolation.
June 28, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28690683/microchip-based-3d-cell-culture-using-polymer-nanofibers-generated-by-solution-blow-spinning
#3
Chengpeng Chen, Alexandra D Townsend, Scott A Sell, R Scott Martin
Polymer nano/micro fibers have found many applications including 3D cell culture and the creation of wound dressings. The fibers can be produced by a variety of techniques that include electrospinning, the primary disadvantage of which include the requirement for a high voltage supply (which may cause issues such as polymer denaturation) and lack of portability. More recently, solution blow spinning, where a high velocity sheath gas is used instead of high voltage, has been used to generate polymer fibers. In this work, we used blow spinning to create nano/microfibers for microchip-based 3D cell culture...
June 14, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28674558/analysis-of-stable-isotope-assisted-metabolomics-data-acquired-by-high-resolution-mass-spectrometry
#4
X Wei, P K Lorkiewicz, B Shi, J K Salabei, B G Hill, S Kim, C J McClain, X Zhang
Stable isotope assisted metabolomics (SIAM) uses stable isotope tracers to support studies of biochemical mechanisms. We report a suite of data analysis algorithms for automatic analysis of SIAM data acquired on a high resolution mass spectrometer. To increase the accuracy of isotopologue assignment, metabolites detected in the unlabeled samples were used as reference metabolites to generate possible isotopologue candidates for analysis of peaks detected in the labeled samples. An iterative linear regression model was developed to deconvolute the overlapping isotopic peaks of isotopologues present in a full MS spectrum, where the threshold for the weight factor was determined by a simulation study assuming different levels of Gaussian white noise contamination...
April 21, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/29034007/microfluidic-iterative-mechanical-characteristics-imech-analyzer-for-single-cell-metastatic-identification
#5
Hesam Babahosseini, Jeannine S Strobl, Masoud Agah
This study describes the development of a microfluidic biosensor called the iterative mechanical characteristics (iMECH) analyzer which enables label-free biomechanical profiling of individual cells for distinction between metastatic and non-metastatic human mammary cell lines. Previous results have demonstrated that pulsed mechanical nanoindentation can modulate the biomechanics of cells resulting in distinctly different biomechanical responses in metastatic and non-metastatic cell lines. The iMECH analyzer aims to move this concept into a microfluidic, clinically more relevant platform...
February 7, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28286575/chiral-determination-of-3-4-methylenedioxypyrovalerone-enantiomers-in-rat-serum
#6
Michael D Hambuchen, Howard P Hendrickson, S Michael Owens
The emerging stimulant drug of abuse (3,4)-methylenedioxypyrovalerone [(R,S)-MDPV] is self-administered as a racemic mixture by intranasal, iv, oral, and smoking routes. The individual enantiomers are known to have widely different pharmacological effects, with (S)-MDPV showing much greater potency than (R)-MDPV in pharmacological testing. The goal of these studies was to develop and validate an analytical method for quantitation of (R)-MDPV, (S)-MDPV and (R,S)-MDPV in small volumes of rat serum using a chiral separation column and liquid chromatography-mass spectrometry...
January 28, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28217148/profiling-metals-in-cordyceps-sinensis-by-using-inductively-coupled-plasma-mass-spectrometry
#7
Xin Wei, Hankun Hu, Baogeng Zheng, Zikri Arslan, Hung-Chung Huang, Weidong Mao, Yi-Ming Liu
Cordyceps sinensis (C. sinensis) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2...
January 28, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28713441/analysis-of-raw-biofluids-by-mass-spectrometry-using-microfluidic-diffusion-based-separation
#8
Joshua Heinemann, Brigit Noon, Daniel Willems, Katherine Budeski, Brian Bothner
Elucidation and monitoring of biomarkers continues to expand because of their medical value and potential to reduce healthcare costs. For example, biomarkers are used extensively to track physiology associated with drug addiction, disease progression, aging, and industrial processes. While longitudinal analyses are of great value from a biological or healthcare perspective, the cost associated with replicate analyses is preventing the expansion of frequent routine testing. Frequent testing could deepen our understanding of disease emergence and aid adoption of personalized healthcare...
January 21, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28458724/online-fluorescence-anisotropy-immunoassay-for-monitoring-insulin-secretion-from-islets-of-langerhans
#9
Adrian M Schrell, Nikita Mukhitov, Lian Yi, Joel E Adablah, Joshua Menezes, Michael G Roper
Insulin secretion from islets of Langerhans is a dynamic process that is essential for maintaining glucose homeostasis. The ability to measure dynamic changes in insulin levels upon glucose stimulation from single islets will allow testing of therapeutics and investigating mechanisms of defective secretion observed in metabolic diseases. Most approaches to date for measurement of rapid changes in insulin levels rely on separations, making the assays difficult to translate to non-specialist laboratories. To enable rapid measurements of secretion dynamics from a single islet in a manner that will be more suitable for transfer to non-specialized laboratories, a microfluidic online fluorescence anisotropy immunoassay was developed...
January 7, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28194233/checkpoints-for-preliminary-identification-of-small-molecules-found-enriched-in-autophagosomes-and-activated-mast-cell-secretions-analyzed-by-comparative-uplc-ms-e
#10
Chad P Satori, Marzieh Ramezani, Joseph S Koopmeiners, Audrey F Meyer, Jose A Rodriguez-Navarro, Michelle M Kuhns, Thane H Taylor, Christy L Haynes, Joseph J Dalluge, Edgar A Arriaga
We report the use of ultra high performance liquid chromatography (UPLC) coupled with acquisition of low- and high-collision energy mass spectra (MS(e)) to explore small molecule compositions that are unique to either enriched-autophagosomes or secretions of chemically activated murine mast cells. Starting with thousands of features, each defined by a chromatographic retention time, m/z values and ion intensities, manual examination of the extracted ion chromatograms (XIC) of chemometrically selected features was essential to eliminate false positives, occurring at rates of 33, 14 and 37% in samples of three biological systems...
2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28446924/differential-leukocyte-counting-via-fluorescent-detection-and-image-processing-on-a-centrifugal-microfluidic-platform
#11
Max L Balter, Alvin I Chen, C Amara Colinco, Alexander Gorshkov, Brian Bixon, Vincent Martin, Alexander Fromholtz, Timothy J Maguire, Martin L Yarmush
Centrifugal microfluidics has received much attention in the last decade for the automation of blood testing at the point-of-care, specifically for the detection of chemistries, proteins, and nucleic acids. However, the detection of common blood cells on-disc, particularly leukocytes, remains a challenge. In this paper, we present two analytical methods for enumerating leukocytes on a centrifugal platform using a custom-built fluorescent microscope, acridine orange nuclear staining, and image processing techniques...
December 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28496521/on-chip-fluorescent-labeling-using-reversed-phase-monoliths-and-microchip-electrophoretic-separations-of-selected-preterm-birth-biomarkers
#12
Mukul Sonker, Rui Yang, Vishal Sahore, Suresh Kumar, Adam T Woolley
On-chip preconcentration, purification, and fluorescent labeling are desirable sample preparation steps to achieve complete automation in integrated microfluidic systems. In this work, we developed electrokinetically operated microfluidic devices for solid-phase extraction and fluorescent labeling of preterm birth (PTB) biomarkers. Reversed-phase monoliths based on different acrylate monomers were photopolymerized in cyclic olefin copolymer microdevices and studied for the selective retention and elution of a fluorescent dye and PTB biomarkers...
November 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27812369/the-performance-of-single-and-multi-collector-icp-ms-instruments-for-fast-and-reliable-34-s-32-s-isotope-ratio-measurements
#13
Ondrej Hanousek, Marion Brunner, Daniel Pröfrock, Johanna Irrgeher, Thomas Prohaska
The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC, measurement repeatability, within-lab reproducibility and deviation from certified values as well as a study on instrumental isotopic fractionation (IIF) and the calculation of the combined standard measurement uncertainty...
November 14, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28392839/recent-advances-in-microscale-western-blotting
#14
Brittany J Sanders, Daniel C Kim, Robert C Dunn
Western blotting is a ubiquitous tool used extensively in the clinical and research settings to identify proteins and characterize their levels. It has rapidly become a mainstay in research laboratories due to its specificity, low cost, and ease of use. The specificity arises from the orthogonal processes used to identify proteins. Samples are first separated based on size and then probed with antibodies specific for the protein of interest. This confirmatory approach helps avoid pitfalls associated with antibody cross-reactivity and specificity issues...
October 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28127406/multiplexed-detection-of-pathogen-specific-dna-using-engineered-zinc-finger-proteins-without-target-amplification
#15
Moon-Soo Kim, Juhwa Kim
Multiplexed detection of pathogen-specific DNA sequences in a simple and reliable way is in great demand for clinical and biomedical applications. However, there is still a lack of available DNA detection methods that are simple and pathogen-selective for point-of-care (POC) testing. Here, we report a novel zinc finger protein (ZFP)-based chemiluminescent method for direct detection of pathogenic double-stranded DNA (dsDNA) in a multiplexed platform. ZFPs are custom-designed to identify unique pathogenic DNA sequences...
October 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28989532/disulfide-bond-characterization-of-endogenous-igg3-monoclonal-antibodies-using-lc-ms-an-investigation-of-igg3-disulfide-mediated-isoforms
#16
Jude C Lakbub, Daniel F Clark, Ishan S Shah, Zhikai Zhu, Eden P Go, Thomas J Tolbert, Heather Desaire
The use of monoclonal antibodies (mAbs) for the manufacture of innovator and biosimilar biotherapeutics has increased tremendously in recent years. From a structural perspective, mAbs have high disulfide bond content, and the correct disulfide connectivity is required for proper folding and to maintain their biological activity. Therefore, disulfide linkage mapping is an important component of mAB characterization for ensuring drug safety and efficacy. The native disulfide linkage patterns of all four subclasses of IgG antibodies have been well established since the late 1960s...
August 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27617038/3d-printed-microfluidic-devices-fabrication-advantages-and-limitations-a-mini-review
#17
Chengpeng Chen, Benjamin T Mehl, Akash S Munshi, Alexandra D Townsend, Dana M Spence, R Scott Martin
A mini-review with 79 references. In this review, the most recent trends in 3D-printed microfluidic devices are discussed. In addition, a focus is given to the fabrication aspects of these devices, with the supplemental information containing detailed instructions for designing a variety of structures including: a microfluidic channel, threads to accommodate commercial fluidic fittings, a flow splitter; a well plate, a mold for PDMS channel casting; and how to combine multiple designs into a single device. The advantages and limitations of 3D-printed microfluidic devices are thoroughly discussed, as are some future directions for the field...
August 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28018490/detecting-levels-of-polyquaternium-10-pq-10-via-potentiometric-titration-with-dextran-sulphate-and-monitoring-the-equivalence-point-with-a-polymeric-membrane-based-polyion-sensor
#18
Stephen A Ferguson, Xuewei Wang, Mark E Meyerhoff
Polymeric quaternary ammonium salts (polyquaterniums) have found increasing use in industrial and cosmetic applications in recent years. More specifically, polyquaternium-10 (PQ-10) is routinely used in cosmetic applications as a conditioner in personal care product formulations. Herein, we demonstrate the use of potentiometric polyion-sensitive polymeric membrane-based electrodes to quantify PQ-10 levels. Mixtures containing both PQ-10 and sodium lauryl sulfate (SLS) are used as model samples to illustrate this new method...
August 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27574530/detection-and-identification-of-sugar-alcohol-sweeteners-by-ion-mobility-spectrometry
#19
Christopher A Browne, Thomas P Forbes, Edward Sisco
The rapid and sensitive detection of sugar alcohol sweeteners was demonstrated using ion mobility spectrometry (IMS). IMS provides a valuable alternative in sensitivity, cost, and analysis speed between the lengthy gold-standard liquid chromatography-mass spectrometry (LC-MS) technique and rapid point-of-measurement disposable colorimetric sensors, for the Food and Nutrition industry's quality control and other "foodomics" area needs. The IMS response, characteristic signatures, and limits of detection for erythritol, pentaerythritol, xylitol, inositol, sorbitol, mannitol, and maltitol were evaluated using precise inkjet printed samples...
July 28, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28090219/integrated-microfluidic-aptasensor-for-mass-spectrometric-detection-of-vasopressin-in-human-plasma-ultrafiltrate
#20
J Yang, J Zhu, R Pei, J A Oliver, D W Landry, M N Stojanovic, Q Lin
We present a microfluidic aptamer-based biosensor for detection of low-molecular-weight biomarkers in patient samples. Using a microfluidic device that integrates aptamer-based specific analyte extraction, isocratic elution, and detection by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we demonstrate rapid, sensitive and label-free detection of arginine vasopressin (AVP) in human plasma ultrafiltrate. AVP molecules in complex matrices are specifically captured by an aptamer that is immobilized on microbeads via affinity binding in a microchamber...
July 14, 2016: Analytical Methods: Advancing Methods and Applications
journal
journal
42739
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"