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Phosphoric acid

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https://www.readbyqxmd.com/read/28337253/hepatoprotective-effects-of-antrodia-cinnamomea-the-modulation-of-oxidative-stress-signaling-in-a-mouse-model-of-alcohol-induced-acute-liver-injury
#1
Yange Liu, Juan Wang, Lanzhou Li, Wenji Hu, Yidi Qu, Yipei Ding, Lina Meng, Lirong Teng, Di Wang
In the present study, the components of A. cinnamomea (AC) mycelia were systematically analyzed. Subsequently, its hepatoprotective effects and the underlying mechanisms were explored using a mouse model of acute alcohol-induced liver injury. AC contained 25 types of fatty acid, 16 types of amino acid, 3 types of nucleotide, and 8 types of mineral. The hepatoprotective effects were observed after 2 weeks of AC treatment at doses of 75 mg/kg, 225 mg/kg, and 675 mg/kg in the mouse model. These effects were indicated by the changes in the levels of aspartate aminotransferase, alanine aminotransferase, several oxidation-related factors, and inflammatory cytokines in serum and/or liver samples...
2017: Oxidative Medicine and Cellular Longevity
https://www.readbyqxmd.com/read/28335986/on-the-formation-and-role-of-reactive-oxygen-species-in-light-driven-lpmo-oxidation-of-phosphoric-acid-swollen-cellulose
#2
K B Möllers, H Mikkelsen, T I Simonsen, D Cannella, K S Johansen, M J Bjerrum, C Felby
Light-driven activation of lytic polysaccharide monooxygenases (LPMOs) has been attributed to the transfer of high redox potential electrons from excited photopigments to the enzyme. However, due to the formation of reactive oxygen species (ROS) in such a system, not only electrons from the pigments but also ROS could be part of the enzyme mechanism. This work investigates the role of ROS in the oxidation of phosphoric acid swollen cellulose (PASC) by a light-driven LPMO system. Our results clearly show that the addition of superoxide dismutase or catalase to remove ROS did not attenuate the capacity of the light-driven LPMO system to oxidize PASC, as measured by formation of oxidized oligosaccharides...
March 18, 2017: Carbohydrate Research
https://www.readbyqxmd.com/read/28334920/spe-hplc-determination-of-chlorogenic-and-phenolic-acids-in-coffee
#3
Pelin Köseoglu Yilmaz, Ufuk Kolak
A new solid phase extraction-high-performance liquid chromatography method with ultraviolet detection was developed and validated for the determination of three chlorogenic acids (5-O-caffeoylquinic, 3-O-caffeoylquinic and 4-O-caffeoylquinic acids) and six phenolic acids (caffeic, ferulic, sinapic, protocatechuic, p-hydroxybenzoic acid (PHBA) and vanillic acid (VA)) in coffee bean samples. Extraction was performed using hydrophilic-lipophilic balance cartridges. Separations were accomplished using a C18 guard column (10 × 2...
March 18, 2017: Journal of Chromatographic Science
https://www.readbyqxmd.com/read/28332764/catalytic-asymmetric-n-alkylation-of-indoles-and-carbazoles-through-1-6-conjugate-addition-of-aza-para-quinone-methides
#4
Min Chen, Jianwei Sun
Catalytic asymmetric N-alkylation of indoles and carbazoles represents a family of important but underdeveloped reactions. Herein, we describe a new organocatalytic strategy in which in situ generated aza-para-quinone methides are employed as the alkylating reagent. With the proper choice of a chiral phosphoric acid and an N-protective group, the intermolecular C-N bond formation with various indole and carbazole nucleophiles proceeded efficiently under mild conditions with excellent enantioselectivity and functional-group compatibility...
March 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28332576/catalytic-asymmetric-radical-aminoperfluoroalkylation-and-aminodifluoromethylation-of-alkenes-to-versatile-enantioenriched-fluoroalkyl-amines
#5
Jin-Shun Lin, Fu-Li Wang, Xiao-Yang Dong, Wei-Wei He, Yue Yuan, Su Chen, Xin-Yuan Liu
Although great success has been achieved in asymmetric fluoroalkylation reactions via nucleophilic or electrophilic processes, the development of asymmetric radical versions of this type of reactions remains a formidable challenge because of the involvement of highly reactive radical species. Here we report a catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical sources, providing a versatile platform to access four types of enantioenriched α-tertiary pyrrolidines bearing β-perfluorobutanyl, trifluoromethyl, difluoroacetyl and even difluoromethyl groups in excellent yields and with excellent enantioselectivity...
March 23, 2017: Nature Communications
https://www.readbyqxmd.com/read/28330526/different-spectrophotometric-and-chromatographic-methods-for-determination-of-mepivacaine-and-its-toxic-impurity
#6
Nada S Abdelwahab, Nehal F Fared, Mohamed Elagawany, Esraa H Abdelmomen
Stability-indicating spectrophotometric, TLC-densitometric, and ultra-performance LC (UPLC) methods were developed forthe determination of mepivacaine HCl (MEP) in the presence of its toxic impurity, 2,6-dimethylanaline (DMA). Different spectrophotometric methods were developed for the determination of MEP and DMA. In a dual-wavelength method combined with direct spectrophotometric measurement, the absorbance difference between 221.4 and 240 nm was used for MEP measurements, whereas the absorbance at 283 nm was used for measuring DMA in the binary mixture...
February 21, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28326759/a-practical-cryogen-free-co2-purification-and-freezing-technique-for-stable-isotope-analysis
#7
Saburo Sakai, Shinichi Matsuda
 Since isotopic analysis by mass spectrometer began in the early 1900s, sample gas for light-element isotopic measurement has been purified by the use of cryogens and vacuum-line systems. However, this conventional purification technique can achieve only certain temperatures, which depend on the cryogens, and can be sustained only as long as there is a continuous cryogen supply. Here, we demonstrate a practical cryogen-free CO2 purification technique using an electrical operated cryocooler for stable isotope analysis...
March 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28325708/use-of-glucose-as-reductant-to-recover-co-from-spent-lithium-ions-batteries
#8
Qi Meng, Yingjie Zhang, Peng Dong
A hydrometallurgical leaching process has been developed for recovery of Co and Li from cathode material (LiCoO2) collected from spent LIBs using a mix solution of glucose and phosphoric acid. The spent LiCoO2 before and after leaching process are analyzed by scanning electron microscopy. A leaching rate of about 98% Co and nearly 100% Li is presented with 1.5mol/L phosphoric acid and 0.02mol/L glucose at 80°C in about 2h. During leaching process, glucose was oxidized into monocarboxylic acid with reduction of Co(III) to Co(II)...
March 18, 2017: Waste Management
https://www.readbyqxmd.com/read/28303719/pentanuclear-lanthanide-mono-organophosphates-synthesis-structure-and-magnetism
#9
Sandeep K Gupta, Stuart K Langley, Kamna Sharma, Keith S Murray, Ramaswamy Murugavel
Research on rare-earth phosphates has recently received substantial interest because of their unique physical and chemical properties. In recent years, because of their low solubility, research interest has been built on developing methodologies to prepare nanostructures and grow single crystals of inorganic rare-earth phosphates. The chemistry of rare-earth organophosphates, however, is still at a latent stage. Contrary to the traditional hydrothermal route, we report rare examples of discrete pentanuclear lanthanide(III) organophosphate clusters assembled from a sterically encumbered monoester of phosphoric acid under mild reaction conditions...
March 17, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28301880/fast-and-green-co2-based-extraction-isolation-and-quantification-of-phenolic-styrax-constituents
#10
Johanna Scheuba, Valerie-Katharina Wronski, Judith M Rollinger, Ulrike Grienke
In this study the first supercritical fluid based protocol for the extraction, analysis, and isolation of six polar compounds, i.e., o-vanillin (1), styracin (2), vanillin (3), trans-cinnamic acid (4), vanillic acid (5), and shikimic acid (6), was developed. First, eight styrax resin products (R1-R8) obtained from various Liquidambar tree species, which are known to contain compounds 2-6, were extracted with a 1 : 1 mixture of supercritical CO2 and EtOH. Within 4 minutes, the compounds were successfully baseline separated on an Acquity UPC(2) BEH 2-EP (3...
March 16, 2017: Planta Medica
https://www.readbyqxmd.com/read/28300242/a-catalytic-enantioselective-approach-to-tetrol-bearing-vicinal-all-carbon-quaternary-stereogenic-centers
#11
Hui Yang, Kou-Sen Cao, Wen-Hua Zheng
The first highly enantioselective catalytic protocol for selective manipulation of tetrol benzylidene acetals through chiral phosphoric acid mediated oxidative desymmetrization is reported. This efficient approach provides a general access to vicinal all-carbon quaternary stereogenic center structural motifs, as well as structures containing vicinal tertiary and quaternary stereocenters enantioselectively. The synthetic utility has been furthermore demonstrated by transformations and gram-scale processes.
March 16, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28298990/an-ex-vivo-shear-and-tensile-bond-strengths-of-orthodontic-molar-tubes-bonded-using-different-techniques
#12
Elham Abu-Alhaija, Mohammad Jaradat, Ahed Alwahadni
BACKGROUND: Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. MATERIAL AND METHODS: The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with 18% hydrochloric acid and pumice (micro-abrasion); group 4: molar tubes bonded to teeth pre-treated with microabrasion with the addition of silane to the base of molar tubes; group 5: molar tubes bonded to teeth pre-treated with microabrasion before conventional acid etching combined with the addition of silane to the base of molar tubes...
March 2017: Journal of Clinical and Experimental Dentistry
https://www.readbyqxmd.com/read/28297310/production-and-quality-control-177-lu-nca-dotmp-as-a-potential-agent-for-bone-pain-palliation
#13
Nafise Salek, Mojtaba Shamsaei, Mohammad Ghannadi Maragheh, Simindokht Shirvani Arani, Ali Bahrami Samani
Skeletal uptake of radiolabeled-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetramethylene phosphoric acid (e.g., (177) Lu-DOTMP) complex, is used for bone pain palliation. The moderate energy of β-emitting 177Lu (T1/2=6.7 d,Eβmax=497 keV) has been considered as a potential radionuclide for development of the bone-seeking radiopharmaceutical. Since the specific activity of the radiolabeled carrier molecules should be high, the "no-carrier-added radionuclides" have significant roles in nuclear medicine...
November 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28295465/quantification-of-piritramide-in-human-colostrum
#14
A Van Eeckhaut, P Vanfleteren, J Van Schoors, Y Van Wanseele, J Poelaert, Y Michotte
WHAT IS KNOWN AND OBJECTIVE: In our university hospital (UZBrussel), one of the options to control post-operative pain after a Caesarean section under general anaesthesia is to administer piritramide by patient-controlled intravenous analgesia (PCIA). As no information is available about the possible transfer of this synthetic narcotic analgesic into breastmilk, women are frequently advised not to breastfeed their newborn. A sensitive liquid chromatographic (LC) method coupled with UV detection will therefore be developed and validated for the quantification of piritramide in colostrum samples to evaluate the presence of the analgesic in the first milk...
March 13, 2017: Journal of Clinical Pharmacy and Therapeutics
https://www.readbyqxmd.com/read/28293949/coomassie-brilliant-blue-g-250-dye-new-application-for-forensic-fingerprint-analysis
#15
Erica Brunelle, Anh Minh Le, Crystal Huynh, Kelly Wingfield, Lenka Halámková, Juliana Agudelo, Jan Halámek
The Bradford reagent, comprised of the Coomassie Brilliant Blue G-250 dye, methanol and phosphoric acid, has been traditionally used for quantifying proteins. Use of this reagent in the Bradford assay relies on the binding of the Coomassie Blue G-250 dye to proteins. However, the ability of the dye to react with a small group of amino acids - arginine, histidine, lysine, phenylalanine, tyrosine, and tryptophan - makes it a viable chemical assay for fingerprint analysis in order to identify the biological sex of the fingerprint originator...
March 15, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28290656/in-situ-synthesis-strategy-for-hierarchically-porous-ni2p-polyhedrons-from-mofs-templates-with-enhanced-electrochemical-properties-for-hydrogen-evolution
#16
Liting Yan, Pengcheng Dai, Ying Wang, Xin Gu, Liangjun Li, Lei Cao, Xuebo Zhao
The development of highly active and stable noble metal-free electrocatalysts of hydrogen evolution reaction (HER) under both acidic and basic conditions for renewable-energy conversion techniques is of great significance. Herein, a practical in situ synthesis strategy for a three-dimensional Ni2P polyhedron with a hierarchically porous structure was presented, which was efficiently obtained from a nickel centered metal-organic frameworks (MOF-74-Ni) by direct low-temperature phosphorization. The as-prepared Ni2P polyhedron showed a high BET surface area (175...
March 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28290202/enantioselective-direct-%C3%AE-arylation-of-pyrazol-5-ones-with-2-indolylmethanols-via-organo-metal-cooperative-catalysis
#17
Zi-Qi Zhu, Yang Shen, Jin-Xi Liu, Ji-Yu Tao, Feng Shi
The first catalytic asymmetric α-arylation of pyrazol-5-ones has been established by using 2-indolylmethanols as direct electrophilic arylation reagents under the cooperative catalysis of Pd(0) and a chiral phosphoric acid, which afforded the α-arylation products of pyrazol-5-ones in generally high yields and good enantioselectivities (up to 99% yield, >99% ee).
March 14, 2017: Organic Letters
https://www.readbyqxmd.com/read/28288424/slow-pyrolyzed-biochars-from-crop-residues-for-soil-metal-loid-immobilization-and-microbial-community-abundance-in-contaminated-agricultural-soils
#18
Avanthi Deshani Igalavithana, Jinje Park, Changkook Ryu, Young Han Lee, Yohey Hashimoto, Longbin Huang, Eilhann E Kwon, Yong Sik Ok, Sang Soo Lee
This study evaluated the feasibility of using biochars produced from three types of crop residues for immobilizing Pb and As and their effects on the abundance of microbial community in contaminated lowland paddy (P-soil) and upland (U-soil) agricultural soils. Biochars were produced from umbrella tree [Maesopsis eminii] wood bark [WB], cocopeat [CP], and palm kernel shell [PKS] at 500 °C by slow pyrolysis at a heating rate of 10 °C min(-1). Soils were incubated with 5% (w w(-1)) biochars at 25 °C and 70% water holding capacity for 45 d...
March 6, 2017: Chemosphere
https://www.readbyqxmd.com/read/28287572/rapid-mix-preparation-of-bioinspired-nanoscale-hydroxyapatite-for-biomedical-applications
#19
Caroline J Wilcock, Piergiorgio Gentile, Paul V Hatton, Cheryl A Miller
Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest regarding the use of bioinspired nanoscale hydroxyapatite (nHA). However, biological apatite is known to be calcium-deficient and carbonate-substituted with a nanoscale platelet-like morphology. Bioinspired nHA has the potential to stimulate optimal bone tissue regeneration due to its similarity to bone and tooth enamel mineral. Many of the methods currently used to fabricate nHA both in the laboratory and commercially, involve lengthy processes and complex equipment...
February 23, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28282045/enantioselective-amine-%C3%AE-functionalization-via-palladium-catalysed-c-h-arylation-of-thioamides
#20
Pankaj Jain, Pritha Verma, Guoqin Xia, Jin-Quan Yu
Saturated aza-heterocycles are highly privileged building blocks that are commonly encountered in bioactive compounds and approved therapeutic agents. These N-heterocycles are also incorporated as chiral auxiliaries and ligands in asymmetric synthesis. As such, the development of methods to functionalize the α-methylene C-H bonds of these systems enantioselectively is of great importance, especially in drug discovery. Currently, enantioselective lithiation with (-)-sparteine followed by Pd(0) catalysed cross-coupling to prepare α-arylated amines is largely limited to pyrrolidines...
February 2017: Nature Chemistry
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