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Magnetic Nuclear Resonance

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https://www.readbyqxmd.com/read/28929139/rapid-and-near-complete-dissolution-of-wood-lignin-at-%C3%A2-80%C3%A2-c-by-a-recyclable-acid-hydrotrope
#1
Liheng Chen, Jinze Dou, Qianli Ma, Ning Li, Ruchun Wu, Huiyang Bian, Daniel J Yelle, Tapani Vuorinen, Shiyu Fu, Xuejun Pan, Junyong J Y Zhu
We report the discovery of the hydrotropic properties of a recyclable aromatic acid, p-toluenesulfonic acid (p-TsOH), for potentially low-cost and efficient fractionation of wood through rapid and near-complete dissolution of lignin. Approximately 90% of poplar wood (NE222) lignin can be dissolved at 80°C in 20 min. Equivalent delignification using known hydrotropes, such as aromatic salts, can be achieved only at 150°C or higher for more than 10 hours or at 150°C for 2 hours with alkaline pulping. p-TsOH fractionated wood into two fractions: (i) a primarily cellulose-rich water-insoluble solid fraction that can be used for the production of high-value building blocks, such as dissolving pulp fibers, lignocellulosic nanomaterials, and/or sugars through subsequent enzymatic hydrolysis; and (ii) a spent acid liquor stream containing mainly dissolved lignin that can be easily precipitated as lignin nanoparticles by diluting the spent acid liquor to below the minimal hydrotrope concentration...
September 2017: Science Advances
https://www.readbyqxmd.com/read/28928712/metabolomics-as-a-tool-for-the-characterization-of-drug-resistant-epilepsy
#2
Federica Murgia, Antonella Muroni, Monica Puligheddu, Lorenzo Polizzi, Luigi Barberini, Gianni Orofino, Paolo Solla, Simone Poddighe, Francesco Del Carratore, Julian L Griffin, Luigi Atzori, Francesco Marrosu
PURPOSE: Drug resistance is a critical issue in the treatment of epilepsy, contributing to clinical emergencies and increasing both serious social and economic burdens on the health system. The wide variety of potential drug combinations followed by often failed consecutive attempts to match drugs to an individual patient may mean that this treatment stage may last for years with suboptimal benefit to the patient. Given these challenges, it is valuable to explore the availability of new methodologies able to shorten the period of determining a rationale pharmacologic treatment...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28928507/characteristics-of-xanthosoma-sagittifolium-roots-during-cooking-using-physicochemical-analysis-uniaxial-compression-multispectral-imaging-and-low-field-nmr-spectroscopy
#3
Abena Achiaa Boakye, María Gudjónsdóttir, Jacob Lercke Skytte, Ioannis S Chronakis, Faustina Dufie Wireko-Manu, Ibok Oduro
To effectively promote the industrial utilization of cocoyam (Xanthosoma sagittifolium) roots for enhanced food sustainability and security, there is a need to study their molecular, mechanical and physicochemical properties in detail. The physicochemical and textural characteristics of the red and white varieties of cocoyam roots were thus analysed by low field nuclear magnetic resonance relaxometry, multispectral imaging, uniaxial compression testing, and relevant physicochemical analysis in the current study...
August 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28928219/o2-sensing-associated-glycosylation-exposes-the-f-box-combining-site-of-the-dictyostelium-skp1-subunit-in-e3-ubiquitin-ligases
#4
M Osman Sheikh, David Thieker, Gordon Chalmers, Christopher M Schafer, Mayumi Ishihara, Parastoo Azadi, Robert J Woods, John N Glushka, Brad Bendiak, James H Prestegard, Christopher M West
Skp1 is a conserved protein linking cullin-1 to F-box proteins in SCF (Skp1-Cullin1-F-box) E3 ubiquitin ligases, which modify protein substrates with polyubiquitin chains that typically target them for 26S proteasome-mediated degradation. In Dictyostelium (a social amoeba), Toxoplasma gondii (the agent for human toxoplasmosis), and other protists, Skp1 is regulated by a unique pentasaccharide attached to hydroxylated Pro-143 within its C-terminal F-box binding domain. Prolyl hydroxylation of Skp1 contributes to O2-dependent Dictyostelium development, but full glycosylation at that position is required for optimal O2 sensing...
September 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28927618/geraniol-grafted-chitosan-oligosaccharide-as-a-potential-antibacterial-agent
#5
Lin Yue, Jingru Li, Wanwen Chen, Xiaoli Liu, Qixing Jiang, Wenshui Xia
The novel derivatives of geraniol grafted chitosan oligosaccharide were synthesized via substitution and deprotection reaction, respectively. The products were identified by Fourier transform infrared (FT-IR), (1)H nuclear magnetic resonance (NMR), X-ray diffraction analysis (XRD), Thermogravimetric analysis (TGA) and UV-vis absorption spectroscopy. It is revealed that the derivatives exhibited a good solubility, thermal stability and antibacterial properties.
November 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28927614/fast-microwave-assisted-green-synthesis-of-xanthan-gum-grafted-acrylic-acid-for-enhanced-methylene-blue-dye-removal-from-aqueous-solution
#6
Edwin Makhado, Sadanand Pandey, Philiswa N Nomngongo, James Ramontja
In the present project, graft polymerization was employed to synthesis a novel adsorbent using acrylic acid (AA) and xanthan gum (XG) for cationic methylene dye (MB(+)) removal from aqueous solution. The XG was rapidly grafted with acrylic acid (CH2=CHCOOH) under microwave heating. Fourier-transform infrared spectroscopy (FTIR), Proton Nuclear magnetic resonance spectroscopy ((1)H NMR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Thermal gravimetric analysis (TGA) techniques were used to verify the adsorbent formed under optimized reaction conditions...
November 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28927612/facile-fabrication-of-redox-ph-dual-stimuli-responsive-cellulose-hydrogel
#7
Hongchen Liu, Liduo Rong, Bijia Wang, Ruyi Xie, Xiaofeng Sui, Hong Xu, Linping Zhang, Yi Zhong, Zhiping Mao
A cellulose-based multi-responsive hydrogel was prepared by the facile incorporation of enamine and disulfide bonds in the same system at physiological pH. The cellulose hydrogel was obtained by simply mixing aqueous solutions of cellulose acetoacetate (CAA) and cystamine dihydrochloride (CYS) at room temperature. The internal morphology, structure, and mechanical properties of the cellulose hydrogel were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and Raman spectroscopies, nuclear magnetic resonance (NMR), and water retention, porosity, and rheology measurements...
November 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28927610/structure-and-immunomodulatory-activity-of-a-sulfated-agarose-with-pyruvate-and-xylose-substitutes-from-polysiphonia-senticulosa-harvey
#8
Xiaoliang Zhao, Guangling Jiao, Yi Yang, Miaomiao Li, Qinying Li, Xiaojiang Wang, Chao Cai, Guoyun Li, Jiejie Hao, Guangli Yu
A charged and size uniform polysaccharide PS2 was prepared from red seaweed Polysiphonia senticulosa Harvey. Based on nuclear magnetic resonance (NMR), fourier transform infrared (FTIR) spectroscopy, and electrospray ionization collision-induced-dissociation mass spectrometry (ESI-CID-MS(n)) analysis, PS2 was determined to be a novel 6-O-sulfated agarose which was mainly composed of a repeating unit of alternating (1→3)-linked 6-sulfated-β-d-galactose and (1→4)-linked 3,6-anhydro-α-l-galactose in association with small amount of pyruvate substituted on galactose residues and xylose (Xyl) branched at C2 position of 3,6-anhydro-galactose...
November 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28927234/metabolic-profiling-of-central-nervous-system-disease-in-trypanosoma-brucei-rhodesiense-infection
#9
Sabrina D Lamour, Vincent P Alibu, Elaine Holmes, Jeremy M Sternberg
Background: The progression of Human African Trypanosomiasis from the early hemolymphatic stage to the late meningoencephalitic stage is of critical diagnostic importance as it determines the choice of potentially toxic drug regimens. Current diagnostic criteria involving analysis of cerebrospinal fluid (CSF) for parasites and/or pleiocytosis are sensitive, but recent evidence suggests that specificity may be poor. Methods: We used an untargeted global metabolic profiling approach for the discovery of novel candidate stage diagnostic markers in CSF from Trypanosoma brucei rhodesiense patients using 1H nuclear magnetic resonance (NMR) spectroscopy...
September 12, 2017: Journal of Infectious Diseases
https://www.readbyqxmd.com/read/28926698/quantification-of-lignin-and-its-structural-features-in-plant-biomass-using-13-c-lignin-as-internal-standard-for-pyrolysis-gc-sim-ms
#10
Gijs van Erven, Ries de Visser, Donny W H Merkx, Willem Strolenberg, Peter De Gijsel, Harry Gruppen, Mirjam A Kabel
Understanding mechanisms underlying plant biomass recalcitrance at molecular level can only be achieved by accurate analyses of both content and structural features of the molecules involved. Current quantification of lignin is, however, majorly based on unspecific gravimetric analysis after sulphuric acid hydrolysis. Hence, our research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric (13)C lignin was used as internal standard (IS) for lignin quantification via analytical pyrolysis coupled to gas chromatography with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS)...
September 19, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28926062/selectivity-of-solid-phase-extraction-for-dissolved-organic-matter-in-the-hypersaline%C3%A2-da-qaidam-lake-china
#11
Keli Yang, Yaoling Zhang, Yaping Dong, Wu Li
Dissolved organic matter (DOM) was isolated from the hypersaline Da Qaidam Lake using solid-phase extraction (SPE) methods with five different adsorbents: ENVI-Carb (non-porous graphitized carbon), HLB, PPL, and XAD-8 (polymer based), and ENVI-18 (silica based). Structure-selective assessments of SPE-DOM isolated using the different adsorbents were conducted using a combination of complementary analysis techniques, including dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) analysis, as well as elemental analysis, Fourier transformed infrared spectroscopy (FTIR), (1)H nuclear magnetic resonance ((1)H NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS)...
September 19, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28925291/isolation-of-a-novel-compound-mimo2-from-the-methanolic-extract-of-moringa-oleifera-leaves-protective-effects-against-vanadium-induced-cytotoxity
#12
Olumayowa O Igado, Jan Glaser, Mario Ramos-Tirado, Ezgi Eylül Bankoğlu, Foluso A Atiba, Ulrike Holzgrabe, Helga Stopper, James O Olopade
Moringa oleifera is reported to be a miracle plant, with positive effects on practically every system in the animal body. The methanolic extract of Moringa oleifera leaves was fractionated using liquid-liquid fractionation, column chromatography and preparative high-performance liquid chromatography (HPLC). Bioassay guided fractionation using Ferric Reducing Antioxidant Power (FRAP) was used to determine the fraction with the highest antioxidative power. Chemical structure was elucidated with nuclear magnetic resonance (NMR) spectroscopy...
September 19, 2017: Drug and Chemical Toxicology
https://www.readbyqxmd.com/read/28924531/efficacy-of-metabolically-supported-chemotherapy-combined-with-ketogenic-diet-hyperthermia-and-hyperbaric-oxygen-therapy-for-stage-iv-triple-negative-breast-cancer
#13
Mehmet Salih İyikesici, Abdul Kadir Slocum, Ayshe Slocum, Ferhan Bulent Berkarda, Miriam Kalamian, Thomas N Seyfried
Triple-negative breast cancer (TNBC) is more aggressive and metastatic than other breast cancer types. Cytotoxic chemotherapy is presently the predominant systemic therapy for TNBC patients. This case report highlights the influence of metabolically supported chemotherapy (MSCT), ketogenic diet (KD), hyperthermia (HT), and hyperbaric oxygen therapy (HBOT) in an overweight 29-year-old woman with stage IV (T4N3M1) triple-negative invasive ductal carcinoma of the breast. The patient presented with an observable mass in her left breast detected during a physical examination in December 2015...
July 7, 2017: Curēus
https://www.readbyqxmd.com/read/28924155/distinguishing-faceted-oxide-nanocrystals-with-17-o-solid-state-nmr-spectroscopy
#14
Yuhong Li, Xin-Ping Wu, Ningxin Jiang, Ming Lin, Li Shen, Haicheng Sun, Yongzheng Wang, Meng Wang, Xiaokang Ke, Zhiwu Yu, Fei Gao, Lin Dong, Xuefeng Guo, Wenhua Hou, Weiping Ding, Xue-Qing Gong, Clare P Grey, Luming Peng
Facet engineering of oxide nanocrystals represents a powerful method for generating diverse properties for practical and innovative applications. Therefore, it is crucial to determine the nature of the exposed facets of oxides in order to develop the facet/morphology-property relationships and rationally design nanostructures with desired properties. Despite the extensive applications of electron microscopy for visualizing the facet structure of nanocrystals, the volumes sampled by such techniques are very small and may not be representative of the whole sample...
September 18, 2017: Nature Communications
https://www.readbyqxmd.com/read/28923777/an-improved-method-for-permeability-estimation-of-the-bioclastic-limestone-reservoir-based-on-nmr-data
#15
Xinmin Ge, Yiren Fan, Jianyu Liu, Li Zhang, Yujiao Han, Donghui Xing
Permeability is an important parameter in formation evaluation since it controls the fluid transportation of porous rocks. However, it is challengeable to compute the permeability of bioclastic limestone reservoirs by conventional methods linking petrophysical and geophysical data, due to the complex pore distributions. A new method is presented to estimate the permeability based on laboratory and downhole nuclear magnetic resonance (NMR) measurements. We divide the pore space into four intervals by the inflection points between the pore radius and the transversal relaxation time...
September 9, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28923766/development-of-stability-enhanced-ternary-solid-dispersions-via-combinations-of-hpmcp-and-soluplus-%C3%A2-processed-by-hot-melt-extrusion
#16
Ahmad B Albadarin, Catherine B Potter, Mark Davis, Javed Iqbal, Sachin Korde, Sudhir Pagire, Anant Paradkar, Gavin Walker
The aim of this study was to evaluate a novel combination of hydroxypropyl methylcellulose phthalate (HPMCP-HP-50) and Soluplus(®) polymers for enhanced physicochemical stability and solubility of the produced amorphous solid dispersions (ASDs). This was achieved using hot melt extrusion (HME) to convert the crystalline active pharmaceutical ingredient (API) into a more soluble amorphous form within the ternary systems. Itraconazole (ITZ), a Biopharmaceutics Classification System class II (BCS II) API, was utilized as the model drug...
September 15, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28923651/high-resolution-magic-angle-spinning-nuclear-magnetic-resonance-spectroscopy-for-the-metabolic-assessment-of-acute-rejection-after-cardiac-transplantation-in-rats
#17
C W Lee, J S Lee, C W Woo, S Kim
PURPOSE: To evaluate the potential of high-resolution magic angle spinning (HR-MAS) (1)H nuclear magnetic resonance (NMR) spectroscopy for metabolite characterization and the differentiation of acute rejection after heart transplantation in rat models. METHODS: We transplanted syngeneic heart grafts from Lewis rats (n = 4) and allogeneic heart grafts from F344 rats (n = 4) heterotopically into Lewis recipients. On day 7 postoperatively, the transplanted hearts were harvested for ex vivo (1)H NMR spectroscopy and HR-MAS (1)H NMR spectroscopy...
October 2017: Transplantation Proceedings
https://www.readbyqxmd.com/read/28922450/structural-insight-into-the-xtacc3-xmap215-interaction-from-cd-and-nmr-studies-on-model-peptides
#18
Angélica Partida-Hanon, Miguel A Treviño, Miguel Mompeán, Ma Ángeles Jiménez, Marta Bruix
TACC3 is a centrosomal adaptor protein that plays important roles during mitotic spindle assembly. It interacts with chTOG/XMAP215, which catalyzes the addition of tubulin dimers during microtubule growth. A 3D coiled-coil model for this interaction is available but the structural details are not well described. To characterize this interaction at atomic resolution, we have designed a simplified version of the system based on small peptides. Four different peptides have been studied by circular dichroism and nuclear magnetic resonance both singly and in all possible combinations; namely, five peptide pairs and two trios...
September 18, 2017: Biopolymers
https://www.readbyqxmd.com/read/28921691/quantitative-determination-and-validation-of-octreotide-acetate-using-1-h-nmr-spectroscopy-with-internal-standard-method
#19
Chen Yu, Qian Zhang, Peng-Yao Xu, Yin Bai, Wen-Bin Shen, Bin Di, Meng-Xiang Su
Quantitative nuclear magnetic resonance (qNMR) is a well-established technique in quantitative analysis. We presented a validated (1) H quantitative nuclear magnetic resonance ((1) H-qNMR) method for assay of octreotide acetate (OCT-Ac), a kind of cyclic octopeptide. Deuterium oxide was used to remove the undesired exchangeable peaks, which was referred to as proton exchange, in order to make the quantitative signals isolated in the crowded spectrum of the peptide and ensure precise quantitative analysis. Gemcitabine hydrochloride was chosen as the suitable internal standard (IS)...
September 15, 2017: Magnetic Resonance in Chemistry: MRC
https://www.readbyqxmd.com/read/28921378/chemistry-and-chemical-equilibrium-dynamics-of-bmaa-and-its-carbamate-adducts
#20
Pedro Diaz-Parga, Joy J Goto, V V Krishnan
Beta-N-methylamino-L-alanine (BMAA) has been demonstrated to contribute to the onset of the ALS/Parkinsonism-dementia complex (ALS/PDC) and is implicated in the progression of other neurodegenerative diseases. While the role of BMAA in these diseases is still debated, one of the suggested mechanisms involves the activation of excitatory glutamate receptors. In particular, the excitatory effects of BMAA are shown to be dependent on the presence of bicarbonate ions, which in turn forms carbamate adducts in physiological conditions...
September 18, 2017: Neurotoxicity Research
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