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Simultaneous Determination

Na Guo, Yi-Wei Jiang, Ping Kou, Zhi-Ming Liu, Thomas Efferth, Yan-Yan Li, Yu-Jie Fu
A simple and efficient method based on cloud point extraction and concentration combined with high performance liquid chromatography was developed for the simultaneous separation and determination of five target compounds (deoxynojirimycin, chlorogenic acid, rutin, isoquercitrin and astragalin) in mulberry leaves samples. Firstly, to obtain a high extraction rate, the ultrasound assisted extraction was developed on acid modified Triton X-114 system. Under the optimal conditions, the total maximum extraction yields of five target compounds reached 20...
February 10, 2019: Journal of Pharmaceutical and Biomedical Analysis
Stuart D Dowall, Victoria A Graham, Tom Fletcher, Roger Hewson
In the UK, research on hazard group 4 (HG4) pathogens requires specialised Containment Level 4 (CL4) facilities. These differ from Biosafety Level 4 (BSL4) conditions in that work is conducted in class III microbiological safety cabinets for primary containment instead of using positive pressure suits. This presents unique challenges associated with the physical restrictions of working in a limited space, and prohibits the use of many techniques and specialist equipment. In consequence, detailed studies on the biology of HG4 pathogens and in particular their immunological relationships with the host are understudied in the UK; for example, the majority of immunological assays with which the immune system is interrogated require specialist equipment that is unsuitable for CL4...
February 13, 2019: Methods: a Companion to Methods in Enzymology
James K Miller, Jieshi Chen, Alexander Sundermann, Jane W Marsh, Melissa I Saul, Kathleen A Shutt, Marissa Pacey, Mustapha M Mustapha, Lee H Harrison, Artur Dubrawski
We present a statistical inference model for the detection and characterization of outbreaks of hospital associated infection. The approach combines patient exposures, determined from electronic medical records, and pathogen similarity, determined by whole-genome sequencing, to simultaneously identify probable outbreaks and their root-causes. We show how our model can be used to target isolates for whole-genome sequencing, improving outbreak detection and characterization even without comprehensive sequencing...
February 13, 2019: Journal of Biomedical Informatics
Benedetta Porro, Alessandro Di Minno, Bianca Rocca, Susanna Fiorelli, Sonia Eligini, Linda Turnu, Simone Barbieri, Alessandro Parolari, Elena Tremoli, Viviana Cavalca
Due to its ability to irreversibly inactivate platelet cyclooxygenase, low-dose aspirin (ASA) is the most widely used antithrombotic agent. Although, studies in specific types of patients with cardiovascular disease (CVD) have shown an incomplete inhibition of platelet's cyclooxygenase, which may increase the variability in drug response. Some aspects of ASA pharmacokinetics (PK) still need further investigation. In this study, we aimed to characterise the contribution of esterase enzymes to ASA hydrolysis in the peripheral blood and to assess their activity in 36 healthy subjects (Ctrl) and 77 CVD patients...
February 13, 2019: Biochemical Pharmacology
Fen-Ying Kong, Rong-Fang Li, Lei Yao, Zhong-Xia Wang, Heng-Ye Li, Wei-Xin Lv, Wei Wang
An electrochemical sensor is described for the simultaneous determination of the pollutants catechol (CC) and hydroquinone (HQ). A glassy carbon electrode (GCE) was modified with reduced graphene oxide, Fe3 O4 and gold nanoparticles and then showed a pair of well-defined voltammetric peaks for CC and HQ. Its oxidation peak potentials (located at 0.21 and 0.10 V vs. Ag/AgCl) are well separated, and this makes it suitable for simultaneous determination of the two isomers. Under optimal conditions, the oxidation peak currents of CC and HQ increase linearly in the 0...
February 15, 2019: Mikrochimica Acta
Anderson Martin Santos, Ademar Wong, Fernando Campanhã Vicentini, Orlando Fatibello-Filho
A carbon paste electrode (CPE) was modified with graphite oxide (GrO) and β-cyclodextrin (CD) to obtain a sensor for simultaneous voltammetric determination of levodopa (LD), piroxicam (PRX), ofloxacin (OFX) and methocarbamol (MCB). The morphology, structure and electrochemical properties of the functionalized GrO were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, contact angle measurements and cyclic voltammetry. Under the optimal experimental conditions, the sensor is capable of detecting LD, PRX, OFX and MCB by square wave voltammetry (SWV) at working potentials of +0...
February 15, 2019: Mikrochimica Acta
Haiping Huang, Yafeng Yue, Zhongzhen Chen, Yanan Chen, Shuzhen Wu, Jinsheng Liao, Suijun Liu, He-Rui Wen
A nanocomposite is described that consists of TmPO4 and graphene oxide (GO) and is used to modify a glassy carbon electrode (GCE) to obtain a sensor for simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). GO and TmPO4 were synthesized via the Hummers method and by a hydrothermal method, respectively. The nanocomposite was characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction and Fourier transform infrared spectroscopy...
February 15, 2019: Mikrochimica Acta
Margaret M C Lam, Kelly L Wyres, Ryan R Wick, Louise M Judd, Aasmund Fostervold, Kathryn E Holt, Iren Høyland Löhr
BACKGROUND: MDR and hypervirulence (hv) are typically observed in separate Klebsiella pneumoniae populations. However, convergent strains with both properties have been documented and potentially pose a high risk to public health in the form of invasive infections with limited treatment options. OBJECTIVES: Our aim was to characterize the genetic determinants of virulence and antimicrobial resistance (AMR) in two ESBL-producing K. pneumoniae isolates belonging to the international MDR clone ST15...
February 15, 2019: Journal of Antimicrobial Chemotherapy
Aurèle Besse-Patin, Stewart Jeromson, Philipa Levesque-Damphousse, Blandine Secco, Mathieu Laplante, Jennifer L Estall
Precise modulation of hepatic glucose metabolism is crucial during the fasting and feeding cycle and is controlled by the actions of circulating insulin and glucagon. The insulin-signaling pathway requires insulin receptor substrate 1 (IRS1) and IRS2, which are found to be dysregulated in diabetes and obesity. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1A) is a fasting-induced transcriptional coactivator. In nonalcoholic fatty liver disease and in patients with type 2 diabetes, low hepatic PGC1A levels are associated with insulin resistance...
February 15, 2019: Proceedings of the National Academy of Sciences of the United States of America
J Karlsson, M Wallin, M Hallbäck, P A Lönnqvist
BACKGROUND: Effective pulmonary blood flow (COEPBF ) has recently been validated for its ability to measure cardiac output (CO) in children and animals. This study compared COEPBF with the Fick method (COFick ) and CO measurements using an invasive pulmonary artery flow probe (COTS ). The aim of the study was to validate COEPBF against these reference methods in a porcine model of hypoxia-induced selective pulmonary hypertension. METHODS: Ten anaesthetised mechanically ventilated piglets (median weight 23...
March 2019: British Journal of Anaesthesia
Jakub Rok, Zuzanna Rzepka, Michalina Respondek, Artur Beberok, Dorota Wrześniok
Tetracyclines belong to antimicrobial classes with the highest consumption in veterinary medicine and agriculture, which leads to the contamination of the environment and food products, as well as to antibiotic resistance and adverse drug reactions. Chloro-derivatives of tetracyclines are thought to be relatively more phototoxic than others and belong to the most frequently cited drugs as photosensitizers. Melanins are heterogenous biopolymers determining skin, hair and eye colour. They are biosynthesized in a multistep process in melanocytes...
February 12, 2019: Chemico-biological Interactions
A Del Vecchio, F Negro, A Holobar, A Casolo, J P Folland, F Felici, D Farina
KEY POINTS: We propose and validate a method to accurately identify the activity of populations of motor neurons during contractions at maximal rate of force development in humans. The behaviour of the motor neuron pool during rapid voluntary contractions in humans is presented. We show with this approach that the motor neuron recruitment speed and maximal motor unit discharge rate largely explains the individual ability in generating rapid force contractions. The results also indicate that the synaptic inputs received by the motor neurons before force is generated dictate human potential to generate force rapidly...
February 15, 2019: Journal of Physiology
Camila Ihle-Soto, Eduardo Costoya, Juana P Correa, Antonella Bacigalupo, Berenice Cornejo-Villar, Viviana Estadella, Aldo Solari, Sylvia Ortiz, Héctor J Hernández, Carezza Botto-Mahan, David E Gorla, Pedro E Cattan
BACKGROUND: Trypanosoma cruzi is a protozoan parasite that is transmitted by triatomine vectors to mammals. It is classified in six discrete typing units (DTUs). In Chile, domestic vectorial transmission has been interrupted; however, the parasite is maintained in non-domestic foci. The aim of this study was to describe T. cruzi infection and DTU composition in mammals and triatomines from several non-domestic populations of North-Central Chile and to evaluate their spatio-temporal variations...
February 15, 2019: PLoS Neglected Tropical Diseases
David I Walsh, Marilene Pavan, Luis Ortiz, Scott Wick, Johanna Bobrow, Nicholas J Guido, Sarah Leinicke, Dany Fu, Shreya Pandit, Lucy Qin, Peter A Carr, Douglas Densmore
The advancement of synthetic biology requires the ability to create new DNA sequences to produce unique behaviors in biological systems. Automation is increasingly employed to carry out well-established assembly methods of DNA fragments in a multiplexed, high-throughput fashion, allowing many different configurations to be tested simultaneously. However, metrics are required to determine when automation is warranted based on factors such as assembly methodology, protocol details, and number of samples. The goal of our synthetic biology automation work is to develop and test protocols, hardware, and software to investigate and optimize DNA assembly through quantifiable metrics...
February 15, 2019: SLAS Technology
Brian P Chaplin
Growing worldwide population, climate change, and decaying water infrastructure have all contributed to a need for a better water treatment and conveyance model. Distributed water treatment is one possible solution, which relies on the local treatment of water from various sources to a degree dependent on its intended use and, finally, distribution to local consumers. This distributed, fit-for-purpose water treatment strategy requires the development of new modular point-of-use and point-of-entry technologies to bring this idea to fruition...
February 15, 2019: Accounts of Chemical Research
Sibel Yalçın, Mustafa Özyürek
The present work focused on the potential use of brown algae Cystoseira barbata and Cystoseira crinita from the Black Sea coast for removal and speciation analyses of Cr(III,VI) ions from aqueous and wastewater solutions. The biosorption process of Cr(III) and Cr(VI) was designed as a function of pH and contact time. Potentiometric titration and Fourier transform infrared spectroscopy (FT-IR) analysis techniques revealed the potential binding sites present at the surface of the algae for both oxidation states of Cr...
December 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Ana B Lanham, Adrian Oehmen, Gilda Carvalho, Aaron M Saunders, Per H Nielsen, Maria A M Reis
A comprehensive assessment of full-scale enhanced biological phosphorus removal (EBPR) plants (five plants, 19 independent tests) was undertaken to determine their effectiveness in terms of aerobic and anoxic P removal. By comparing parallel P uptake tests under only aerobic or under anoxic-aerobic conditions, results revealed that introducing an anoxic stage led to an overall P removal of on average 90% of the P removed under only aerobic conditions. This was achieved with negligible higher PHA and glycogen requirements, 30% lower overall oxygen consumption and with the simultaneous removal of nitrate, reducing up to an estimate of 70% of carbon requirements for simultaneous N and P removal...
December 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Annette M Krais, Christian Kliem, Volker M Arlt, Heinz H Schmeiser
Methylating substances alter DNA by forming N3-methylthymidine (N3mT), a mutagenic base modification. To develop a sensitive analytical method for the detection of N3mT in DNA based on capillary electrophoresis with laser-induced fluorescence detection (CE-LIF), we synthesized the N3mT-3'-phosphate as a chemical standard. The limit of detection was 1.9 amol of N3mT, which corresponds to one molecule of N3mT per 1,000 normal nucleotides or 0.1%. With this method, we demonstrated that the carcinogenic nitrosamine N'-nitrosonornicotine (NNN) induced N3mT in the human lung cancer cell line A549...
February 15, 2019: Electrophoresis
Jun-Tao Cao, Fu-Rao Liu, Xiao-Long Fu, Jin-Xin Ma, Shu-Wei Ren, Yan-Ming Liu
A novel electrochemiluminescence resonance energy transfer (ECL-RET) system using versatile gold nanorods as energy acceptors was introduced into the ECL biochemical analysis. A spatial- and potential-resolved platform coupled with the ECL-RET strategy was developed for simultaneous determination of two acute myocardial infarction markers.
February 15, 2019: Chemical Communications: Chem Comm
Zhongmin Xia, Yulin Zhou, Dongmei Fu, Zengge Wang, Yunsheng Ge, Jun Ren, Qiwei Guo
Carrier screening of spinal muscular atrophy (SMA) can provide reproductive options for carriers and prevent the birth defects. Here, we developed a simple screening test based on melting analysis. The test comprises a duplex PCR with two primer pairs and three probes to simultaneous amplify SMN1, SMN2, and CFTR. By analyzing the melting profiles, we were able to determine the SMN1/SMN2 ratio and SMN1 + SMN2 copy number to subsequently determine the copy number of SMN1. Samples with one copy of SMN1 were considered as "high risk for carrier," while samples with ≥2 copies of SMN1 were considered as "low risk for carrier...
February 15, 2019: Journal of Human Genetics
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