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https://www.readbyqxmd.com/read/28738646/synthesis-characterization-and-application-of-a-novel-multifunctional-stationary-phase-for-hydrophilic-interaction-reversed-phase-mixed-mode-chromatography
#1
Hayriye Aral, K Serdar Çelik, Ramazan Altındağ, Tarık Aral
A novel multifunctional stationary phase based on silica gel was synthesised starting from L- isoleucine and 4-phenylbutylamine and evaluated as a hydrophilic interaction/reversed-phase mixed-mode stationary phase for high-performance liquid chromatography (HPLC). The prepared stationary phase was characterized by elemental analysis, infrared spectroscopy (IR), scanning electron microscopy (SEM), Brunauer, Emmett and Teller (BET) and solid-state (13)C nuclear magnetic resonance (NMR). The mechanisms involved in the chromatographic separation are multi-interaction, including hydrophobic, π-π, hydrogen-bonding, dipole-dipole and ion-dipole interactions...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28737944/in-situ-generated-glycinyl-chloroaminals-for-a-one-pot-synthesis-of-non-proteinogenic-%C3%AE-amino-esters
#2
Shyam S Samanta, Stephane P Roche
An acetyl chloride-mediated cascade transformation involving a primary carbamate, ethyl glyoxylate and various types of nucleophiles is reported for the synthesis of orthogonally protected α-amino esters. These reactions proceeded rapidly to afford the pivotal α-chloroglycine intermediate in excellent yields which can be directly functionalized in situ with various types of nucleophiles. A mild and unique AcOH(cat.)/AcCl system was found to promote an autocatalytic-like condensation and facilitate the multicomponent assembly of non-proteinogenic α-amino esters...
July 24, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28737838/improved-bacterial-identification-directly-from-urine-samples-with-matrix-assisted-laser-desorption-ionization-time-of-flight-mass-spectrometry
#3
Koichi Kitagawa, Katsumi Shigemura, Ken-Ichiro Onuma, Masako Nishida, Mayu Fujiwara, Saori Kobayashi, Mika Yamasaki, Tatsuya Nakamura, Fukashi Yamamichi, Toshiro Shirakawa, Issei Tokimatsu, Masato Fujisawa
BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) contributes to rapid identification of pathogens in the clinic but has not yet performed especially well for Gram-positive cocci (GPC) causing complicated urinary tract infection (UTI). The goal of this study was to investigate the possible clinical use of MALDI-TOF MS as a rapid method for bacterial identification directly from urine in complicated UTI. METHODS: MALDI-TOF MS was applied to urine samples gathered from 142 suspected complicated UTI patients in 2015-2017...
July 24, 2017: Journal of Clinical Laboratory Analysis
https://www.readbyqxmd.com/read/28737185/rationalising-the-effects-of-ionic-liquids-on-a-nucleophilic-aromatic-substitution-reaction
#4
Rebecca R Hawker, Michaela J Wong, Ronald S Haines, Jason B Harper
The nucleophilic aromatic substitution reaction between 1-fluoro-2,4-dinitrobenzene and ethanol was examined in a series of ionic liquids across a range of mole fractions. Temperature-dependent kinetic analyses were undertaken to determine the activation parameters for this reaction at the highest mole fraction. As the mole fraction of ionic liquid was increased, the rate constant of the reaction also increased, however the microscopic origin of the rate enhancement was shown to be different between different ionic liquids and also between different solvent compositions...
July 24, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28737123/development-and-validation-of-eco-friendly-liquid-chromatographic-and-spectrophotometric-methods-for-simultaneous-determination-of-coformulated-drugs-phenylephrine-hydrochloride-and-prednisolone-acetate
#5
Nadia M Mostafa, Ghada M Elsayed, Nagiba Y Hassan, Dina A El Mously
Five simple, sensitive, and eco-friendly LC and UV spectrophotometric methods have been developed for the simultaneous determination of phenylephrine hydrochloride (PHE) and prednisolone acetate (PRD) in their combined dosage form. The first method was reversed-phase (RP) LC using methanol–water–heptane-1-sulfonic acid sodium salt (75 + 25 + 0.1, v/v/w) as a mobile phase. Separation was achieved using an XSelect HSS reversed-phase C18 analytical column (250 × 4.6 mm, 5µm). The flow rate was 1...
July 24, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28736619/the-role-of-orthobiologics-in-foot-and-ankle-surgery-allogenic-bone-grafts-and-bone-graft-substitutes
#6
REVIEW
James Wee, Gowreeson Thevendran
Orthobiologics are biological substances that are used therapeutically for their positive effects on healing skeletal and soft-tissue injuries. The array of orthobiological products currently available to the foot and ankle surgeon is wide, and includes bone allografts, bone substitutes, growth factors, and chondral scaffolds. Nonetheless, despite the surge in interest and usage of orthobiologics, there remains a relative paucity of research addressing their specific applications in foot and ankle surgery. In this review, we attempt to provide an overview of the literature on commonly available allogenic bone grafts and bone substitutes...
June 2017: EFORT open reviews
https://www.readbyqxmd.com/read/28735893/mechanistic-and-kinetic-study-on-the-reaction-of-methylperoxy-radical-with-atomic-iodine
#7
Yunju Zhang, Ruojing Song, Yuxi Sun, Jingyu Sun, Rongshun Wang
Singlet and triplet potential energy surfaces for the CH3O2 with I reaction have been investigated computationally to propose the reaction mechanisms and possible products. Multichannel RRKM theory and transition-state theory have been used to compute the overall and individual rate constants at 200-3000K and 10(-14)-10(14)Torr. On the singlet PES, addition-elimination, substitution and H-abstraction mechanisms are located, and the addition-elimination mechanism is dominant. At 70Torr with N2 as bath gas, IM1(CH3OOI) formed by collisional stabilization is dominated at 200-300K, whereas CH2O and HIO are the major products at the temperatures between 350 and 3000K; The title reaction exhibits the typical falloff behavior...
May 5, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28735533/kinetics-of-photoelectrochemical-oxidation-of-methanol-on-hematite-photoanodes
#8
Camilo A Mesa, Andreas Kafizas, Laia Francàs, Stephanie R Pendlebury, Ernest Pastor, Yimeng Ma, Florian Le Formal, Matthew Mayer, Michael Grätzel, James R Durrant
The kinetics of photoelectrochemical (PEC) oxidation of methanol, as a model organic substrate, on α-Fe2O3 photoanodes are studied using photo-induced absorption spectroscopy and transient photocurrent measurements. Methanol is oxidized on α-Fe2O3 to formaldehyde with near unity Faradaic efficiency. A rate law analysis under quasi-steady state conditions of PEC methanol oxidation indicates that rate of reaction is second order in the density of surface holes on hematite and independent of the applied potential...
July 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28735437/prospective-and-retrospective-study-of-videoconference-telemedicine-follow-up-after-elective-neurosurgery-results-of-a-pilot-program
#9
Melissa Reider-Demer, Pushpa Raja, Neil Martin, Mariel Schwinger, Diana Babayan
Existing literature suggests that use of telemedicine during postoperative appointments can increase access to care and is valued by patients and providers alike. While research examining the clinical equivalency of telemedicine visits for postoperative care has been growing, few studies have reported on telemedicine follow-up after neurosurgery. This study examined if a videoconferencing visit could substitute for an in-person clinic visit for elective neurosurgical cases in the USA. This was a single-center prospective study of patients who underwent elective neurosurgical procedures (aneurysm clipping, resection of cavernous angiomas, resection of arterial venous malformation, microvascular decompression for trigeminal neuralgia and hemifacial spasm, and certain benign brain tumors) and were offered telemedicine follow-up care by an allied health professional during the first 90 days after neurosurgery...
July 22, 2017: Neurosurgical Review
https://www.readbyqxmd.com/read/28734191/evolutionary-dynamics-of-recent-peste-des-petits-ruminants-virus-epidemic-in-china-during-2013-2014
#10
Jingyue Bao, Qinghua Wang, Lin Li, Chunju Liu, Zhicheng Zhang, Jinming Li, Shujuan Wang, Xiaodong Wu, Zhiliang Wang
Peste des petits ruminants virus (PPRV) causes a highly contagious disease, peste des petits ruminants (PPR), in sheep and goats which has been considered as a serious threat to the local economy in Africa and Asia. However, the in-depth evolutionary dynamics of PPRV during an epidemic is not well understood. We conducted phylogenetic analysis on genomic sequences of 25 PPRV strains from China 2013-2014 outbreaks. All these strains clustered into a novel clade in lineage 4. An evolutionary rate of 2.61 × 10(-6) nucleotide substitutions per site per day was estimated, dating the most recent common ancestor of PPRV China 2013-2014 strains to early August 2013...
July 19, 2017: Virology
https://www.readbyqxmd.com/read/28734139/%C3%AE-nfluenza-a-h3n2-genetic-variants-in-vaccinated-patients-in-northern-greece
#11
A Melidou, G Gioula, M Exindari, E Ioannou, K Gkolfinopoulou, T Georgakopoulou, S Tsiodras, A Papa
BACKGROUND: Influenza A(H3N2) viruses predominated during the influenza 2016/2017 season and showed extensive genetic diversification. A high vaccination failure rate was noticed during the 2016/17 season in Greece, especially among the elderly. OBJECTIVES: The scope of the study was to investigate the genetic characteristics of A(H3N2) circulating viruses and viruses detected in vaccinated patients. STUDY DESIGN: Virus samples originated from vaccinated and unvaccinated patients, obtained at the National Influenza Centre for northern Greece...
July 14, 2017: Journal of Clinical Virology: the Official Publication of the Pan American Society for Clinical Virology
https://www.readbyqxmd.com/read/28732966/effect-of-ultrasonic-waves-on-the-water-turbidity-during-the-oxidation-of-phenol-formation-of-hydro-peroxo-complexes
#12
Natalia Villota, Jose M Lomas, Luis M Camarero
Analysis of the kinetics of aqueous phenol oxidation by a sono-Fenton process reveals that the via involving ortho-substituted intermediates prevails: catechol (25.0%), hydroquinone (7.7%) and resorcinol (0.6%). During the oxidation, water rapidly acquires color that reaches its maximum intensity at the maximum concentration of p-benzoquinone. Turbidity formation occurs at a slower rate. Oxidant dosage determines the nature of the intermediates, being trihydroxylated benzenes (pyrogallol, hydroxyhydroquinone) and muconic acid the main precursors causing turbidity...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732904/preparation-and-characterization-of-mucosal-adhesive-and-two-step-drug-releasing-cetirizine-chitosan-nanoparticle
#13
Xiaoping Yu, Yuzhi Mu, Mengxue Xu, Guixue Xia, Juan Wang, Ya Liu, Xiguang Chen
To develop a functional nanosized mucosal drug delivery system, a series of amphiphilic cetirizine-chitosan polymer (CTZ-CSs) were constructed. CTZ-CSs could self-assemble into nanoparticles (NPs) which gradually evolved from irregular aggregates to spherical particles with an increasing substitution degree (DS) in CTZ group. The average particle size of CTZ-CSs-NPs with nano ZS90 Zetasizer varied from 153.92nm to 184.48nm and their zeta potential varied between +19.14mV and +22.93mV. Biocompatibility assay exhibited CTZ-CS-NPs had few adverse effects within a certain concentration range...
October 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28732854/self-assembled-hyaluronic-acid-nanoparticles-for-controlled-release-of-agrochemicals-and-diosgenin
#14
Javier Pérez Quiñones, Oliver Brüggemann, Carlos Peniche Covas, Dmitri A Ossipov
Commercial sodium hyaluronate (HA) and synthetic hydrazide-modified HA were functionalized with diosgenin and two agrochemicals (brassinosteroids DI31 and S7) with degree of substitution ranging from 5.6 to 13.1%. The HA-steroid conjugates were studied with FTIR, (1)H NMR and differential scanning calorimetry. Dynamic light scattering revealed self-assembly of the HA-steroid conjugates into stable negatively charged nanoparticles of around 159nm-441nm in water, which after drying appeared as 140nm-370nm spherically shaped nanoparticles according to transmission electron microscopy...
October 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28732465/genome-wide-signals-of-positive-selection-in-strongylocentrotid-sea-urchins
#15
Kord M Kober, Grant H Pogson
BACKGROUND: Comparative genomics studies investigating the signals of positive selection among groups of closely related species are still rare and limited in taxonomic breadth. Such studies show great promise in advancing our knowledge about the proportion and the identity of genes experiencing diversifying selection. However, methodological challenges have led to high levels of false positives in past studies. Here, we use the well-annotated genome of the purple sea urchin, Strongylocentrotus purpuratus, as a reference to investigate the signals of positive selection at 6520 single-copy orthologs from nine sea urchin species belonging to the family Strongylocentrotidae paying careful attention to minimizing false positives...
July 21, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28731590/handheld-fetal-doppler-device-for-assessing-heart-rate-in-neonatal-resuscitation
#16
Rinshu Shimabukuro, Kozo Takase, Sachiko Ohde, Isao Kusakawa
BACKGROUND: The use of neonatal 3-lead electrocardiograms (Neo-ECG) is suggested as a method for the assessment of heart rate (HR) in neonatal resuscitation, but primary childbirth facilities (i.e., maternity clinics or maternity homes) are not sufficiently equipped for this. The objective of this study was to confirm the potential of using a handheld fetal Doppler device (FDD), widely used to assess HR in labor room resuscitation, and to compare its equivalency to Neo-ECG. METHODS: In low-risk full-term infants, HR was measured 5 times/minute in minutes 1-5 postpartum using the FDD and Neo-ECG, and their equivalence was compared...
July 21, 2017: Pediatrics International: Official Journal of the Japan Pediatric Society
https://www.readbyqxmd.com/read/28731202/on-the-brink-the-highly-reduced-plastomes-of-nonphotosynthetic-ericaceae
#17
Thomas W A Braukmann, Michael B Broe, Saša Stefanović, John V Freudenstein
Ericaceae (the heather family) is a large and diverse group of plants that forms elaborate symbiotic relationships with mycorrhizal fungi, and includes several nonphotosynthetic lineages. Using an extensive sample of fully mycoheterotrophic (MH) species, we explored inter- and intraspecific variation as well as selective constraints acting on the plastomes of these unusual plants. The plastomes of seven MH genera were analysed in a phylogenetic context with two geographically disparate individuals sequenced for Allotropa, Monotropa, and Pityopus...
July 21, 2017: New Phytologist
https://www.readbyqxmd.com/read/28730648/calcineurin-inhibitor-withdrawal-or-tapering-for-kidney-transplant-recipients
#18
REVIEW
Krishna M Karpe, Girish S Talaulikar, Giles D Walters
BACKGROUND: Calcineurin inhibitors (CNI) can reduce acute transplant rejection and immediate graft loss but are associated with significant adverse effects such as hypertension and nephrotoxicity which may contribute to chronic rejection. CNI toxicity has led to numerous studies investigating CNI withdrawal and tapering strategies. Despite this, uncertainty remains about minimisation or withdrawal of CNI. OBJECTIVES: This review aimed to look at the benefits and harms of CNI tapering or withdrawal in terms of graft function and loss, incidence of acute rejection episodes, treatment-related side effects (hypertension, hyperlipidaemia) and death...
July 21, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/28729697/identification-and-structural-characterization-of-lytu-a-unique-peptidoglycan-endopeptidase-from-the-lysostaphin-family
#19
Vytas Raulinaitis, Helena Tossavainen, Olli Aitio, Jarmo T Juuti, Keiichi Hiramatsu, Vesa Kontinen, Perttu Permi
We introduce LytU, a short member of the lysostaphin family of zinc-dependent pentaglycine endopeptidases. It is a potential antimicrobial agent for S. aureus infections and its gene transcription is highly upregulated upon antibiotic treatments along with other genes involved in cell wall synthesis. We found this enzyme to be responsible for the opening of the cell wall peptidoglycan layer during cell divisions in S. aureus. LytU is anchored in the plasma membrane with the active part residing in the periplasmic space...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28729316/relationship-between-receipt-of-substitutable-for-fee-vaccines-and-completion-of-the-expanded-programme-on-immunisation-a-cross-sectional-study-in-fujian-china
#20
Jiang-Nan Wu, Da-Jin Li, Yong Zhou, Mei-Rong Du, Hai-Lan Piao
OBJECTIVE: The aim of this study was to evaluate the relationship between receipt of the substitutable-for-fee vaccines (SFV) and completion of the expanded programme on immunisation (EPI). DESIGN AND SETTINGS: A cross-sectional study was conducted in Fujian province, China. PARTICIPANTS: Children who were born from 1 September 2009 to 31 August 2011, and who had been residing in the township for at least 3 months, were randomly recruited from 34 townships...
July 20, 2017: BMJ Open
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