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Analytical Techniques

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https://www.readbyqxmd.com/read/29166547/chemical-metabolome-assay-by-high-resolution-orbitrap-mass-spectrometry-and-assessment-of-associated-antitumoral-activity-of-actinocephalus-divaricatus
#1
Ana C Zanatta, Angela Mari, Milena Masullo, Iracilda Zeppone Carlos, Wagner Vilegas, Sonia Piacente, Lourdes Campaner Dos Santos
RATIONALE: Actinocephalus divaricatus (Eriocaulaceae) is an important source of income for the rural communities as it is sold as an ornamental plant. To date, no investigation has been conducted concerning the chemical composition and biological studies of the aerial parts of A. divaricatus. METHODS: The methanolic extract of the aerial parts of this species was chemically characterized. We applied an analytical dereplication approach based on Liquid Chromatography coupled to High Resolution Orbitrap Mass Spectrometry in order to develop, identify and define rapidly the metabolite fingerprint of the aerial parts of A...
November 22, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/29165984/on-chip-lipid-extraction-using-super-absorbent-polymers-for-mass-spectrometry
#2
Geul Bang, Young Hwan Kim, Junghyo Yoon, Yeong Jun Yu, Seok Chung, Jeong Ah Kim
Pre-treatment of samples is the one of most important steps in analytical methods for efficient and accurate results. Typically, an extraction method used for lipid analysis with mass spectrometry is accompanied by complex liquid-liquid extraction. We have devised a simple, rapid, and efficient lipid extraction method using super absorbent polymers (SAPs) and developed a high-throughput lipid extraction platform based on a microfluidic system. Since SAPs can rapidly absorb an aqueous solution from a raw sample and convert it into the gel, the lipid extraction process can be remarkably simplified...
November 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29165867/applying-behavior-analytic-methodology-to-the-science-and-practice-of-environmental-enrichment-in-zoos-and-aquariums
#3
Christina A Alligood, Nicole R Dorey, Lindsay R Mehrkam, Katherine A Leighty
Environmental enrichment in zoos and aquariums is often evaluated at two overlapping levels: published research and day-to-day institutional record keeping. Several authors have discussed ongoing challenges with small sample sizes in between-groups zoological research and have cautioned against the inappropriate use of inferential statistics (Shepherdson, , International Zoo Yearbook, 38, 118-124; Shepherdson, Lewis, Carlstead, Bauman, & Perrin, Applied Animal Behaviour Science, 147, 298-277; Swaisgood, , Applied Animal Behaviour Science, 102, 139-162; Swaisgood & Shepherdson, , Zoo Biology, 24, 499-518)...
May 2017: Zoo Biology
https://www.readbyqxmd.com/read/29165484/diffusiophoresis-in-one-dimensional-solute-gradients
#4
Jesse T Ault, Patrick B Warren, Sangwoo Shin, Howard A Stone
The diffusiophoretic motion of suspended colloidal particles under one-dimensional solute gradients is solved using numerical and analytical techniques. Similarity solutions are developed for the injection and withdrawal dynamics of particles into semi-infinite pores. Furthermore, a method of characteristics formulation of the diffusion-free particle transport model is presented and integrated to realize particle trajectories. Analytical solutions are presented for the limit of small particle diffusiophoretic mobility Γp relative to the solute diffusivity Ds for particle motions in both semi-infinite and finite domains...
November 22, 2017: Soft Matter
https://www.readbyqxmd.com/read/29165121/association-of-asian-dust-with-daily-medical-consultations-for-pollinosis-in-fukuoka-city-japan
#5
Soyoko Sakata, Shoko Konishi, Chris Fook Sheng Ng, Reiko Kishikawa, Chiho Watanabe
BACKGROUND: The objective is to examine the association between AD and the daily number of medical consultations for pollinosis in Fukuoka City. METHODS: We analyzed 65,488 daily medical consultations for pollinosis from 4 clinics in Fukuoka City from February to April, 1989-2012. Time-series analyses were performed to estimate the clinic-specific relative risk (RR) of clinical pollinosis associated with AD, adjusting for airborne pollen, suspended particulate matter (SPM), meteorological and temporal factors...
April 4, 2017: Environmental Health and Preventive Medicine
https://www.readbyqxmd.com/read/29165065/electrochemical-nucleic-acid-based-biosensing-of-drugs-of-abuse-and-pharmaceuticals
#6
Susana Campuzano, Maia Pedrero, Jose M Pingarron
Nowadays, studies of the interactions of DNA with small molecular drugs, especially anti-tumor agents, antibiotics and drugs of abuse are currently performed to explore their mechanism of action and develop new drugs with lower side effects and high curative properties. Currently, electrochemical biosensors are considered a very promising alternative analytical tool to conventional more complex techniques for drug determination due to rapidness, low cost, high sensitivity, compatibility with microfabrication technology, intuitively understandable design and simple operation mode...
November 20, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/29164865/label-free-dna-assay-by-metal-stable-isotope-detection
#7
Rui Liu, Chaoqun Wang, Yuming Xu, Jianyu Hu, Dongyan Deng, Yi Lv
The interest in label-free bioassays is increasing rapidly because of their simple procedure and direct information of the interaction between the target molecule and the sensing unit. One of the major obstacles in the application of label-free biosensors is the difficulty to produce stable and reproducible optical, electric, electrochemical, or magnetic properties for the sensitive detection of the target molecules. In this work, we demonstrated a label-free DNA assay, by directly measuring the intrinsic 63Cu and 65Cu stable isotopes inside the double strand DNA-templated Cu nanoparticles...
November 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29164853/microfluidic-free-flow-electrophoresis-based-solvent-exchanger-for-continuously-operating-lab-on-chip-applications
#8
Franziska D Zitzmann, Heinz-Georg Jahnke, Simon Pfeiffer, Ronny Frank, Felix Nitschke, Laura Mauritz, Bernd Abel, Detlev Belder, Andrea A Robitzki
For miniaturization and integration of chemical synthesis and analytics on small length scales, the development of complex lab on chip (LOC) systems is in the focus of many current research projects. While application specific synthesis and analytic modules and LOC devices are widely described, the combination and integration of different modules is intensively investigated. Problems for in-line processes such as solvent incompatibilities, e.g., for a multistep synthesis or the combination of an organic drug synthesis with a cell-based biological activity testing system, require a solvent exchange between serialized modules...
November 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29164479/spectro-analytical-computational-and-in-vitro-biological-studies-of-novel-substituted-quinolone-hydrazone-and-it-s-metal-complexes
#9
Narsimha Nagula, Sudeepa Kunche, Mohmed Jaheer, Ravi Mudavath, Sreekanth Sivan, Sarala Devi Ch
Some novel transition metal [Cu (II), Ni (II) and Co (II)] complexes of nalidixic acid hydrazone have been prepared and characterized by employing spectro-analytical techniques viz: elemental analysis, (1)H-NMR, Mass, UV-Vis, IR, TGA-DTA, SEM-EDX, ESR and Spectrophotometry studies. The HyperChem 7.5 software was used for geometry optimization of title compound in its molecular and ionic forms. Quantum mechanical parameters, contour maps of highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) and corresponding binding energy values were computed using semi empirical single point PM3 method...
November 21, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/29164136/factors-associated-with-health-related-quality-of-life-among-hypertensive-patients-in-kathmandu-nepal
#10
Saruna Ghimire, Praful Pradhananga, Binaya Kumar Baral, Naveen Shrestha
Introduction: Nepal has a high prevalence of hypertension. While improving the overall health-related quality of life (HRQOL) is a central tenet to public health plans in developed nations, this focus has yet to be articulated in Nepal. Therefore, this study aims to identify the factors associated with HRQOL among hypertensive patients in Nepal. Method: The EuroQol-5Dimension HRQOL survey was administered to 180 hypertensive patients, attending the outpatient clinic at Shahid Gangalal National Heart Center in Kathmandu, Nepal...
2017: Frontiers in Cardiovascular Medicine
https://www.readbyqxmd.com/read/29163307/on-nomological-validity-and-auxiliary-assumptions-the-importance-of-simultaneously-testing-effects-in-social-cognitive-theories-applied-to-health-behavior-and-some-guidelines
#11
Martin S Hagger, Daniel F Gucciardi, Nikos L D Chatzisarantis
Tests of social cognitive theories provide informative data on the factors that relate to health behavior, and the processes and mechanisms involved. In the present article, we contend that tests of social cognitive theories should adhere to the principles of nomological validity, defined as the degree to which predictions in a formal theoretical network are confirmed. We highlight the importance of nomological validity tests to ensure theory predictions can be disconfirmed through observation. We argue that researchers should be explicit on the conditions that lead to theory disconfirmation, and identify any auxiliary assumptions on which theory effects may be conditional...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/29161918/in-process-rheometry-as-a-pat-tool-for-hot-melt-extrusion
#12
A L Kelly, T Gough, M Isreb, R Dhumal, J W Jones, S Nicholson, A B Dennis, A Paradkar
Real time measurement of melt rheology has been investigated as a Process Analytical Technology (PAT) to monitor hot melt extrusion of an Active Pharmaceutical Ingredient (API) in a polymer matrix. A developmental API was melt mixed with a commercial copolymer using a heated twin screw extruder at different API loadings and set temperatures. The extruder was equipped with an instrumented rheological slit die which incorporated three pressure transducers flush mounted to the die surface. Pressure drop measurements within the die at a range of extrusion throughputs were used to calculate rheological parameters such as shear viscosity and exit pressure, related to shear and elastic melt flow properties respectively...
November 22, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/29161021/recent-advances-in-solid-nano-pores-channel-analysis
#13
Zi Long, Shenshan Zhan, Pengcheng Gao, Yongqian Wang, Xiaoding Lou, Fan Xia
Inspired by the natural phenomenon that various types of transmembrane pores and ion channels in the range of 1-100 nm are found in each biological cell, playing crucial roles in various significant physiological activities such as maintaining cell osmotic balance and stabilizing cell volume, different biomimetic nanodevices (nano-pore/channel) with various characteristics have emerged as an attractive and powerful platform, and have been used for a wide range of applications. As the key components of any nano-pore/channel-based applications, the nano-pore/channel can be broadly sorted into two types, biological and solid state...
November 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29160880/low-temperature-growth-of-gallium-oxide-thin-films-via-plasma-enhanced-atomic-layer-deposition
#14
Richard O'Donoghue, Julian Rechmann, Morteza Aghaee, Detlef Rogalla, Hans-Werner Becker, Mariadriana Creatore, Andreas Dirk Wieck, Anjana Devi
Herein we describe an efficient low temperature (60-160 °C) plasma enhanced atomic layer deposition (PEALD) process for gallium oxide (Ga2O3) thin films using hexakis(dimethylamido)digallium [Ga(NMe2)3]2 with oxygen (O2) plasma on Si(100). The use of O2 plasma was found to have a significant improvement on the growth rate and deposition temperature when compared to former Ga2O3 processes. The process yielded the second highest growth rates (1.5 Å per cycle) in terms of Ga2O3 ALD and the lowest temperature to date for the ALD growth of Ga2O3 and typical ALD characteristics were determined...
November 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29160870/engineering-high-performance-hairpin-stacking-circuits-for-logic-gate-operation-and-highly-sensitive-biosensing-assay-of-microrna
#15
Yueli Xing, Xinmin Li, Taixian Yuan, Wei Cheng, Dandan Li, Tianxiao Yu, Xiaojuan Ding, Shijia Ding
Recently, hairpin stacking circuits (HSC) based on toehold-mediated strand displacement have been engineered to detect nucleic acids and proteins. However, the three metastable hairpins in a HSC system can potentially react non-specifically in the absence of a catalyst, limiting its practical application. Here, we developed a unique hairpin design guideline to eliminate circuit leakage of HSC, and the high-performance HSC was successfully implemented on logic gate building and biosensing. We began by analyzing the sources of circuit leakage and optimizing the toehold lengths of hairpins in the HSC system based on the surface plasmon resonance (SPR) technique...
November 21, 2017: Analyst
https://www.readbyqxmd.com/read/29160759/sensitivity-enhancement-of-aminoglycosides-in-hydrophilic-interaction-liquid-chromatography-with-tandem-mass-spectrometry-by-post-column-addition-of-trace-sodium-acetate-in-methanol
#16
Daichi Asakawa, Masako Uemura, Takanori Sakiyama, Testuo Yamano
The development of a sensitive and accurate analytical method for monitoring aminoglycosides in food, environmental, and clinical samples is needed for many purposes. This study found that the responses of sodiated and protonated aminoglycosides in hydrophilic interaction chromatography with tandem mass spectrometry were enhanced upon addition of sodium acetate in methanol (5 mg L(-1) at a flow rate of 0.2 mL min(-1)) as a post-column reagent. The sensitivities of sodiated spectinomycin, kanamycin, gentamicins, neomycin, and amikacin were significantly higher than those of the protonated molecules...
November 21, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/29160568/nerve-detection-using-optical-spectroscopy-an-evaluation-in-four-different-models-in-human-and-swine-in-vivo-and-post-mortem
#17
Gerrit C Langhout, Torre M Bydlon, Marjolein van der Voort, Manfred Müller, Jeroen Kortsmit, Gerald Lucassen, Andrea J R Balthasar, Geert-Jan van Geffen, Thorsten Steinfeldt, Henricus J C M Sterenborg, Benno H W Hendriks, Theo J M Ruers
OBJECTIVE: Identification of peripheral nerve tissue is crucial in both surgery and regional anesthesia. Recently, optical tissue identification methods are presented to facilitate nerve identification in transcutaneous procedures and surgery. Optimization and validation of such techniques require large datasets. The use of alternative models to human in vivo, like human post mortem, or swine may be suitable to test, optimize and validate new optical techniques. However, differences in tissue characteristics and thus optical properties, like oxygen saturation and tissue perfusion are to be expected...
November 21, 2017: Lasers in Surgery and Medicine
https://www.readbyqxmd.com/read/29159024/application-of-1-h-nmr-based-metabolomics-for-discrimination-of-different-parts-and-development-of-a-new-processing-workflow-for-cistanche-deserticola
#18
Pingping Zou, Yuelin Song, Wei Lei, Jun Li, Pengfei Tu, Yong Jiang
Cistanche deserticola (CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein, (1)H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD. Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in combination with available databases and authentic compounds. The upper parts of the plant were distinguished from the lower parts by combining (1)H NMR spectroscopic dataset with multivariate statistical analysis...
November 2017: Acta Pharmaceutica Sinica. B
https://www.readbyqxmd.com/read/29157608/retention-and-effective-diffusion-of-model-metabolites-on-porous-graphitic-carbon
#19
Daniel B Lunn, Young J Yun, James W Jorgenson
The study of metabolites in biological samples is of high interest for a wide range of biological and pharmaceutical applications. Reversed phase liquid chromatography is a common technique used for the separation of metabolites, but it provides little retention for polar metabolites. An alternative to C18 bonded phases, porous graphitic carbon has the ability to provide significant retention for both non-polar and polar analytes. The goal of this work is to study the retention and effective diffusion properties of porous graphitic carbon, to see if it is suitable for the wide injection bands and long run times associated with long, packed capillary-scale separations...
November 14, 2017: Journal of Chromatography. A
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
#20
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
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