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Phosphoric acid

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https://www.readbyqxmd.com/read/28231538/biochars-with-excellent-pb-ii-adsorption-property-produced-from-fresh-and-dehydrated-banana-peels-via-hydrothermal-carbonization
#1
Nan Zhou, Honggang Chen, Junting Xi, Denghui Yao, Zhi Zhou, Yun Tian, Xiangyang Lu
Fresh and dehydrated banana peels were used as biomass feedstock to produce highly effective sorbent biochars through a facile one-step hydrothermal carbonization approach with 20%vol phosphoric acid as the reaction medium. The elemental ratio of oxygen content of the two as-prepared biochars were about 20%, and the FT-IR analysis confirmed the existence of abundant surface functional groups such as hydroxyl and carboxyl which greatly enhanced the adsorption performance. The sorbents showed excellent lead clarification capability of 359mg·g(-1) and 193mg·g(-1) for dehydrated and fresh banana peels based biochars, respectively...
February 12, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28230379/enantioselective-hydroaminomethylation-of-olefins-enabled-by-rh-br%C3%A3-nsted-acid-relay-catalysis
#2
Jing Meng, Xing-Han Li, Zhi-Yong Han
Herein, by employing a rhodium catalyst with a commercial ligand and a phosphoric acid catalyst, highly chemo-, regio-, and enantioselective hydroaminomethylation of olefins is realized through a relay catalytic hydroformylation/dynamic kinetic reductive amination process. The method features mild conditions (1 bar of syngas, room temperature in most cases), high yields (up to 99%), and high enantioselectivities (up to >99.5:0.5 er). Besides styrenes, acrylamides also provided the products with high yields and enantioselectivities...
February 23, 2017: Organic Letters
https://www.readbyqxmd.com/read/28229149/recent-advances-in-organocatalytic-enantioselective-transfer-hydrogenation
#3
REVIEW
Ana Maria Faísca Phillips, Armando J L Pombeiro
The organocatalytic reduction of C[double bond, length as m-dash]C and C[double bond, length as m-dash]N double bonds with biomimetic reductants, e.g. Hantzsch 1,4-dihydropyridine esters and benzothiazolines, is reviewed. Very high yields and stereoselectivities have been achieved with a variety of catalysts, including chiral amines, thioureas and phosphoric acids, even with loadings equivalent to those of transition metal-catalyzed reactions in some cases. Reductive amination reactions and the dearomatization of heteroaromatic substrates are the subject of more than one half of the contributions...
February 23, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28223076/leaching-of-rare-earth-elements-from-fluorescent-powder-using-the-tea-fungus-kombucha
#4
Stefanie Hopfe, Katrin Flemming, Falk Lehmann, Robert Möckel, Sabine Kutschke, Katrin Pollmann
In most modern technologies such as flat screens, highly effective magnets and lasers, as well as luminescence phosphors, Rare Earth Elements (REE) are used. Unfortunately no environmentally friendly recycling process exists so far. In comparison to other elements the interaction of microorganisms with REE has been studied to a less extent. However, as REE are ubiquitously present in nature it can be assumed that microorganisms play an important role in the biogeochemistry of REE. This study investigates the potential of organic acid-producing microbes for extracting REE from industrial waste...
February 17, 2017: Waste Management
https://www.readbyqxmd.com/read/28220965/defect-edge-selective-functionalization-of-carbon-materials-by-direct-friedel-crafts-acylation-reaction
#5
REVIEW
Jeong-Min Seo, Loon-Seng Tan, Jong-Beom Baek
Popularly utilized oxidation media, via nitric acid/sulfuric acid mixtures, are too corrosive and oxidizing to preserve structural integrity of highly ordered graphitic materials (carbon nanotubes (CNTs) and graphene). Here, for the most commonly used oxidation method, the important advantages of defect/edge-selective functionalization of carbon materials (CNTs/graphene/graphite) in a polyphosphoric acid (PPA)/phosphorous pentoxide (P2 O5 ) medium are elucidated. The optimized PPA/P2 O5 medium is a mild acid that is not only less corrosive than popularly utilized oxidation media, but also has a strong capability to drive Friedel-Crafts acylation by covalently modifying carbon materials...
February 21, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28216897/high-performance-liquid-chromatography-diode-array-detector-method-for-the-simultaneous-determination-of-five-compounds-in-the-pulp-and-seed-of-sea-buckthorn
#6
Lu Zhao, E Wen, Halmuart Upur, Shuge Tian
CONTEXT: Sea buckthorn (Hippophae rhamnoides L.) as a traditional Chinese medicinal plant has various uses in Xinjiang. OBJECTIVE: A reversed-phase rapid-resolution liquid-chromatography method with diode array detector was developed for simultaneous determination of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the pulp and seed of sea buckthorn, a widely used traditional Chinese medicine for promoting metabolism and treating scurvy and other diseases...
January 2017: Pharmacognosy Magazine
https://www.readbyqxmd.com/read/28213024/sanitizer-efficacy-in-preventing-cross-contamination-of-heads-of-lettuce-during-retail-crisping
#7
Yangjin Jung, Hyein Jang, Mengqi Guo, Jingwen Gao, Karl R Matthews
This study was conducted to provide information regarding mitigation of cross-contamination through the use of sanitizer during crisping at retail outlets. Seven non-inoculated heads and one inoculated head (≈5 log CFU/g) of lettuce were placed into commercial sink filled with 76 L of tap water (TW), electrolyzed water (EW, free chlorine: 43 ± 6 ppm), lactic acid and phosphoric acid-based sanitizer (LPA, pH 2.89), or citric acid-based sanitizer (CA, pH 2.78) and soaked for 5 min. Two subsequent batches (eight non-inoculated heads per batch) were soaked in the same solution...
June 2017: Food Microbiology
https://www.readbyqxmd.com/read/28210992/the-comparison-of-hydrochloric-acid-and-phosphoric%C3%A2-acid-treatments-in-the-preparation-of-montmorillonite-catalysts-for-rna-synthesis
#8
Michael Frank Aldersley, Prakash C Joshi, Yixing Huang
The treatment of clay minerals with a preliminary acid wash and titration to pH 7 has proven to generate catalysts for the most interesting of oligomerization reactions in which activated RNA-nucleotides generate oligomers up to 40-mers. Significantly, not all clay minerals become catalytic following this treatment and none are catalytic in the absence of such treatment. The washing procedure has been modified and explored further using phosphoric acid and the outcomes are compared to those obtained when clay samples are prepared following a hydrochloric acid wash...
February 16, 2017: Origins of Life and Evolution of the Biosphere
https://www.readbyqxmd.com/read/28208997/comparison-of-self-etch-primers-with-conventional-acid-etching-system-on-orthodontic-brackets
#9
Amit Zope, Yogita Zope-Khalekar, Shrikant S Chitko, Veerendra V Kerudi, Harshal Ashok Patil, Prasad Vasudeo Bonde, Pratik Jaltare, Siddhesh G Dolas
INTRODUCTION: The self-etching primer system consists of etchant and primer dispersed in a single unit. The etching and priming are merged as a single step leading to fewer stages in bonding procedure and reduction in the number of steps that also reduces the chance of introduction of error, resulting in saving time for the clinician. It also results in smaller extent of enamel decalcification. AIM: To compare the Shear Bond Strength (SBS) of orthodontic bracket bonded with Self-Etch Primers (SEP) and conventional acid etching system and to study the surface appearance of teeth after debonding; etching with conventional acid etch and self-etch priming, using stereomicroscope...
December 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28198982/molecular-and-morphological-surface-analysis-effect-of-filling-pastes-and-cleaning-agents-on-root-dentin
#10
Vanessa Benetello Dainezi, Alexsandra Shizue Iwamoto, Airton Abrahão Martin, Luís Eduardo Silva Soares, Yumiko Hosoya, Fernanda Miori Pascon, Regina Maria Puppin-Rontani
Objective: This study evaluated the effect of different filling pastes and cleaning agents on the root dentin of primary teeth using Fourier-transformed Raman spectroscopy (FT-Raman), micro energy-dispersive X-ray fluorescence (µ-EDXRF) and scanning electron microscopic (SEM) analysis. Material and Methods: Eighty roots of primary teeth were endodontically prepared and distributed into 4 groups and filled according to the following filling pastes: Control-no filling (CP), Calen®+zinc oxide (CZ), Calcipex II® (CII), Vitapex® (V)...
January 2017: Journal of Applied Oral Science: Revista FOB
https://www.readbyqxmd.com/read/28194912/enantioselective-dearomatization-of-naphthol-derivatives-with-allylic-alcohols-by-cooperative-iridium-and-br%C3%A3-nsted-acid-catalysis
#11
Dan Shen, Qiliang Chen, Peipei Yan, Xiaofei Zeng, Guofu Zhong
The combination of a transition-metal catalyst and organocatalyst was designed to achieve a highly enantioselective system for the allylic dearomatization reaction of naphthols with racemic secondary allylic alcohols. The desired β-naphthalenones, bearing an all-carbon quaternary center, were obtained in good yields with high chemo- and enantioselectivities. The cooperative catalytic system, involving a chiral iridium complex and phosphoric acid, provided measurable improvements in yields, and chemo- and enantioselectivities relative to single-catalyst systems...
February 14, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28193158/transcriptional-and-physiological-analyses-of-fe-deficiency-response-in-maize-reveal-the-presence-of-strategy-i-components-and-fe-p-interactions
#12
Laura Zanin, Silvia Venuti, Anita Zamboni, Zeno Varanini, Nicola Tomasi, Roberto Pinton
BACKGROUND: Under limited iron (Fe) availability maize, a Strategy II plant, improves Fe acquisition through the release of phytosiderophores (PS) into the rhizosphere and the subsequent uptake of Fe-PS complexes into root cells. Occurrence of Strategy-I-like components and interactions with phosphorous (P) nutrition has been hypothesized based on molecular and physiological studies in grasses. RESULTS: In this report transcriptomic analysis (NimbleGen microarray) of Fe deficiency response revealed that maize roots modulated the expression levels of 724 genes (508 up- and 216 down-regulated, respectively)...
February 13, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28192943/ultrafast-chiral-chromatography-as-the-second-dimension-in-two-dimensional-liquid-chromatography-experiments
#13
Chandan L Barhate, Erik L Regalado, Nathan D Contrella, Joon Lee, Junyong Jo, Alexey A Makarov, Daniel W Armstrong, Christopher J Welch
Chromatographic separation and analysis of complex mixtures of closely related species is one of the most challenging tasks in modern pharmaceutical analysis. In recent years, two-dimensional liquid chromatography (2D-LC) has become a valuable tool for improving peak capacity and selectivity. However, the relatively slow speed of chiral separations has limited the use of chiral stationary phases (CSPs) as the second dimension in 2D-LC, especially in the comprehensive mode. Realizing that the recent revolution in the field of ultrafast enantioselective chromatography could now provide significantly faster separations, we herein report an investigation into the use of ultrafast chiral chromatography as a second dimension for 2D chromatographic separations...
January 23, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28190802/alternate-spray-coating-for-the-direct-fabrication-of-hydroxyapatite-films-without-crystal-growth-step-in-solution
#14
Satoshi Watanabe, Rei Kashiwagi, Mutsuyoshi Matsumoto
We discuss an alternate spray-coating technique for the direct fabrication of hydroxyapatite films using metal masks, suction-type spray nozzles and two calcification solutions of calcium hydroxide and phosphoric acid aqueous solutions. Hydroxyapatite films were formed only on the hydrophobic surface of the substrates. Scanning electron microscopy and energy dispersive X-ray spectroscopy showed that the spray-coated films consisted of hydroxyapatite nanoparticles. The Ca/P ratio was estimated to be about 1...
February 10, 2017: Journal of Oleo Science
https://www.readbyqxmd.com/read/28188900/isolation-and-identification-of-a-novel-bacterium-lactobacillus-sakei-subsp-dgh-strain-5-and-optimization-of-growth-condition-for-highest-antagonistic-activity
#15
Amin Tashakor, Mahshid Hosseinzadehdehkordi, Zeynab Emruzi, Dariush Gholami
In the present study, we isolated Lactobacillus sakei strain DGH5 from raw beef meat. This bacterium plays an inhibitory effect against food-spoiling bacteria and food-borne pathogens, including Listeria monocytogenes, a gram-positive and pathogenic bacterium. Lactobacillus sakei strain DGH5 was identified through both phenotypical and biochemical tests accompanied with 16S rRNA sequence analysis. Among all the sources of carbon, nitrogen and phosphorous forms, we selected the most potent compounds to optimize the condition for the highest antagonistic activity...
February 8, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28184212/the-daily-consumption-of-cola-can-determine-hypocalcemia-a-case-report-of-postsurgical-hypoparathyroidism-related-hypocalcemia-refractory-to-supplemental-therapy-with-high-doses-of-oral-calcium
#16
Valentina Guarnotta, Serena Riela, Marina Massaro, Sebastiano Bonventre, Angela Inviati, Alessandro Ciresi, Giuseppe Pizzolanti, Salvatore Benvenga, Carla Giordano
The consumption of soft drinks is a crucial factor in determining persistent hypocalcemia. The aim of the study is to evaluate the biochemical mechanisms inducing hypocalcemia in a female patient with usual high consumption of cola drink and persistent hypocalcemia, who failed to respond to high doses of calcium and calcitriol supplementation. At baseline and after pentagastrin injection, gastric secretion (Gs) and duodenal secretion (Ds) samples were collected and calcium and total phosphorus (Ptot) concentrations were evaluated...
2017: Frontiers in Endocrinology
https://www.readbyqxmd.com/read/28183671/effect-of-phosphorus-precursors-on-the-structure-of-bioactive-calcium-phosphate-silicate-systems
#17
Katalin Sinkó, Anikó Meiszterics, János Rohonczy, Balázs Kobzi, Shiro Kubuki
The main aim of this work was to synthesize calcium phosphate silicate bioceramics by a low energy-consuming sol-gel method applying various phosphorous precursors (triethyl phosphate, phosphoric acid, and ammonium hydrogen phosphate). The investigations concentrated on the influence of phosphorous initial compounds on the bond and crystalline structures and the material quality. The application of the alkoxide and inorganic P-precursors results in considerably different textures. The inorganic PO4-containing precursors lead to sol formations...
April 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28181166/red-light-emitting-diode-based-on-blue-ingan-chip-with-cdte-x-s-1%C3%A2-%C3%A2-x-quantum-dots
#18
Rongfang Wang, Xingming Wei, Liqin Qin, Zhihui Luo, Chunjie Liang, Guohang Tan
Thioglycolic acid-capped CdTe x S(1 - x) quantum dots (QDs) were synthesized through a one-step approach in an aqueous medium. The CdTe x S(1 - x) QDs played the role of a color conversion center. The structural and luminescent properties of the obtained CdTe x S(1 - x) QDs were investigated. The fabricated red light-emitting hybrid device with the CdTe x S(1 - x) QDs as the phosphor and a blue InGaN chip as the excitation source showed a good luminance. The Commission Internationale de L'Eclairage coordinates of the light-emitting diode (LED) at (0...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28174762/multidoped-ln-3-gadolinium-dioxycarbonates-as-tunable-white-light-emitting-phosphors
#19
I Nelli, A M Kaczmarek, F Locardi, V Caratto, G A Costa, R Van Deun
Gadolinium dioxycarbonates co-doped with different visible emitting lanthanides were synthesized via a co-precipitation method using oxalic acid as a precipitating agent. Through XRD and DTA/TG investigations, the type-II hexagonal phase of the lanthanide dioxycarbonates was confirmed for all of the samples. The materials constitute of big agglomerates formed by submicrometrical particles. By varying the Ln(3+) doping percentages and ratios and by changing the excitation wavelength the gadolinium dioxycarbonates activated with Sm(3+), Eu(3+), Tb(3+), Dy(3+) and Tm(3+) showed tunable emission colors...
February 8, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28173697/hydrophobic-organic-skin-as-a-protective-shield-for-moisture-sensitive-phosphor-based-optoelectronic-devices
#20
Paulraj Arunkumar, Yoon Hwa Kim, Ha Jun Kim, Sanjith Unithrattil, Won Bin Im
A moisture-stable, red-emitting fluoride phosphor with an organic hydrophobic skin is reported. A simple strategy was employed to form a metal-free, organic, passivating skin using oleic acid (OA) as a hydrophobic encapsulant via solvothermal treatment. Unlike other phosphor coatings that suffer from initial efficiency loss, the OA-passivated K2SiF6:Mn4+ (KSF-OA) phosphor exhibited the unique property of stable emission efficiency. Control of thickness and a highly transparent passivating layer helped to retain the emission efficiency of the material after encapsulation...
February 8, 2017: ACS Applied Materials & Interfaces
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