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Magnetic resonance spectroscopy

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https://www.readbyqxmd.com/read/28538613/acute-retinal-damage-after-using-a-toxic-perfluoro-octane-for-vitreo-retinal-surgery
#1
J Carlos Pastor, Rosa M Coco, Ivan Fernandez-Bueno, Maria L Alonso-Alonso, Jesús Medina, Aurelio Sanz-Arranz, Fernando Rull, Manuel J Gayoso, Antonio Dueñas, Maria T Garcia-Gutierrez, Lucia Gonzalez-Buendia, Santiago Delgado-Tirado, Emilio Abecia, Miguel Ruiz-Miguel, Miguel A Serrano, Jose M Ruiz-Moreno, Girish K Srivastava
PURPOSE: To describe a series of retinal acute toxicity cases with severe visual loss after intraocular use of a toxic perfluoro-octane (PFO). The clinical presentation is described, and the likely causes are analyzed. New biological methods for testing safety of intraocular medical devices are proposed. METHODS: Information regarding a series of eyes suffering acute severe events after intraocular use of a toxic PFO was analyzed. Four types of spectroscopy, nuclear magnetic resonance, and chromatography were used to identify the potential PFO contaminants...
June 2017: Retina
https://www.readbyqxmd.com/read/28538152/apoptotic-bax-at-oxidatively-stressed-mitochondrial-membranes-lipid-dynamics-and-permeabilization
#2
Artur Peter Günther Dingeldein, Šárka Pokorná, Martin Lidman, Tobias Sparrman, Radek Šachl, Martin Hof, Gerhard Gröbner
Mitochondria are crucial compartments of eukaryotic cells because they function as the cellular power plant and play a central role in the early stages of programmed cell death (apoptosis). To avoid undesired cell death, this apoptotic pathway is tightly regulated by members of the Bcl-2 protein family, which interact on the external surface of the mitochondria, i.e., the mitochondrial outer membrane (MOM), and modulate its permeability to apoptotic factors, controlling their release into the cytosol. A growing body of evidence suggests that the MOM lipids play active roles in this permeabilization process...
May 23, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28535423/chromatographic-separation-and-detection-methods-of-aloe-arborescens-miller-constituents-a-systematic-review
#3
REVIEW
Jilan A Nazeam, Haidy A Gad, Hala M El-Hefnawy, Abdel-Naser B Singab
Aloe arborescens Miller (Family Asphodelaceae) is a member of genus Aloe, which is used in traditional medicine to cure various diseases. The extracts of the plant have been reported to possess anticancer, immunomodulator, antidiabetic, anti-inflammatory and antioxidant activities. The phytochemical investigations have revealed diverse chemical constituents, including phenolics [anthraquinones, anthrones, pyrones, chromones and coumarins], polysaccharides [arborans [(1-4) linked glucomannans, polysaccharide (A, B and C): (A: a linear (1-6)-O-α-glucan, B: a branching (1-2)-O-l-arabinose with (1-2)-O-d-galactose linkages and C: (1-4)-O-β-mannan with 18% acetyl group)]], glycoproteins and carboxypeptidase enzyme...
April 29, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28535056/solid-state-nmr-structure-based-inhibitor-design-to-achieve-selective-inhibition-of-the-parallel-in-register-%C3%AE-sheet-versus-antiparallel-iowa-mutant-%C3%AE-amyloid-fibrils
#4
Qinghui Cheng, Wei Qiang
Solid-state nuclear magnetic resonance (ssNMR) spectroscopy has been widely applied to characterize the high-resolution structures of β-amyloid (Aβ) fibrils. While these structures provide crucial molecular insights on the deposition of amyloid plaques in Alzheimer's diseases (AD), ssNMR structures have been rarely used so far as basis for designing inhibitors. It remains a challenge because the ssNMR-based Aβ fibrils structures were usually obtained with sparsely-isotope-labeled peptides with limited experimental constraints, where the structural models, especially the side-chain coordinates showed restricted precision...
May 23, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28535035/fabrication-of-anti-biofouling-plasma-filtration-membrane-by-electrospinning-process-using-photo-crosslinkable-zwitterionic-phospholipid-polymers
#5
Jiae Seo, Ji-Hun Seo
The goal of this study is to fabricate a stable plasma filtration membrane with anti-biofouling properties via an electrospinning process. To this end, a random-type copolymer consisting of zwitterionic phosphorylcholine (PC) groups and ultraviolet (UV)-crosslinkable phenyl azide groups was synthesized. The zwitterionic PC group provides anti-biofouling properties, and the phenyl azide group enables the stable maintenance of the fibrous nanostructure of hydrophilic zwitterion polymers in aqueous medium via a simple UV curing process...
May 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28534874/shifting-brain-inhibitory-balance-and-connectivity-of-the-prefrontal-cortex-of-adults-with-autism-spectrum-disorder
#6
L A Ajram, J Horder, M A Mendez, A Galanopoulos, L P Brennan, R H Wichers, D M Robertson, C M Murphy, J Zinkstok, G Ivin, M Heasman, D Meek, M D Tricklebank, G J Barker, D J Lythgoe, R A E Edden, S C Williams, D G M Murphy, G M McAlonan
Currently, there are no effective pharmacologic treatments for the core symptoms of autism spectrum disorder (ASD). There is, nevertheless, potential for progress. For example, recent evidence suggests that the excitatory (E) glutamate and inhibitory (I) GABA systems may be altered in ASD. However, no prior studies of ASD have examined the 'responsivity' of the E-I system to pharmacologic challenge; or whether E-I modulation alters abnormalities in functional connectivity of brain regions implicated in the disorder...
May 23, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28534813/synthesis-and-characterization-of-dual-sensitive-fluorescent-nanogels-for-enhancing-drug-delivery-and-tracking-intracellular-drug-delivery
#7
Szu-Yuan Wu, Tilahun Ayane Debele, Yu-Chih Kao, Hsieh-Chih Tsai
Here, dual-sensitive fluorescent branched alginate-polyethyleneimine copolymer (bAPSC) nanogels were synthesized from thiolated alginate and stearoyl-derivatized branched polyethyleneimine. The formation of bAPSC conjugates was confirmed through proton nuclear magnetic resonance and Fourier transform infrared spectroscopy, whereas dynamic light scattering was used to measure the particle size and ζ potential of the nanogels. The fluorescent properties of the nanogels were confirmed through fluorescent spectroscopy and microscopy...
May 19, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28533117/activation-induced-changes-in-gaba-functional-mrs-at-7-t-with-mega-slaser
#8
Chen Chen, Hilmar P Sigurdsson, Sophia E Pépés, Dorothee P Auer, Peter G Morris, Paul S Morgan, Penny A Gowland, Stephen R Jackson
Functional magnetic resonance spectroscopy (fMRS) has been used to assess the dynamic metabolic responses of the brain to a physiological stimulus non-invasively. However, only limited information on the dynamic functional response of γ-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the brain, is available. We aimed to measure the activation-induced changes in GABA unambiguously using a spectral editing method, instead of the conventional direct detection techniques used in previous fMRS studies...
May 19, 2017: NeuroImage
https://www.readbyqxmd.com/read/28532118/facile-synthesis-of-polymeric-fluorescent-organic-nanoparticles-based-on-the-self-polymerization-of-dopamine-for-biological-imaging
#9
Yingge Shi, Ruming Jiang, Meiying Liu, Lihua Fu, Guangjian Zeng, Qing Wan, Liucheng Mao, Fengjie Deng, Xiaoyong Zhang, Yen Wei
Polymeric fluorescent organic nanoparticles (polymer-FONs) have raised considerable research attention for biomedical applications owing to their advantages as compared with fluorescent inorganic nanoparticles and small organic molecules. In this study, we presented an efficient, facile and environment-friendly strategy to produce polymer-FONs, which relied on the self-polymerization of dopamine and polyethyleneimine (PEI) in rather mild conditions. To obtain the final polymer-FONs, aldehyde group-containing copolymers (named as poly(UA-co-PEGMA)) were synthesized by reversible addition-fragmentation chain-transfer polymerization using polyethylene glycol methyl ether methacrylate (PEGMA) and 1-undecen-10-al (UA) as monomers...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532060/design-and-characterization-of-biodegradable-macroporous-hybrid-inorganic-organic-polymer-for-orthopedic-applications
#10
Sunita PremVictor, Jibin Kunnumpurathu, M G Gayathri Devi, K Remya, Vineeth M Vijayan, Jayabalan Muthu
We have engineered hybrid polymer products based on a hybrid inorganic-organic comacromer consisting of hydroxyapatite (HA), carboxyl terminated polypropylene fumarate (CTPPF), PEG300 and ascorbic acid (AA) as a bone graft material. The integration and the spatial distribution of HA in the polymer backbone were facilitated by silanisation and 1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) coupling technique. These comacromers and crosslinked polymer products were characterized by Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR), Scanning electron microscopy (SEM) and Raman mapping techniques...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531831/workflow-methodology-for-rat-brain-metabolome-exploration-using-nmr-lc-ms-and-gc-ms-analytical-platforms
#11
Binta Diémé, Antoine Lefèvre, Lydie Nadal-Desbarats, Laurent Galineau, Blandine Madji Hounoum, Frédéric Montigny, Hélène Blasco, Christian R Andres, Patrick Emond, Sylvie Mavel
We developed a multi-platform approach for the metabolome exploration of rat brain tissue, using liquid chromatography coupled with mass spectrometry (LC-MS), nuclear magnetic resonance spectroscopy (NMR) and gas-chromatography coupled with mass spectrometry (GC-MS). The critical steps for metabolite exploration of cerebral tissues are tissue lysis and metabolites extraction. We first evaluated the impact of freeze-drying compared to wet tissue metabolites extraction using NMR and LC-MS with a reversed phase liquid chromatography...
May 13, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28530722/the-origin-of-enhanced-photocatalytic-activities-of-hydrogenated-tio2-nanoparticles
#12
Yani Liu, Haifeng Feng, Xiaobing Yan, Jiaou Wang, Huagui Yang, Yi Du, Weichang Hao
The photocatalytic activity of semiconductors is largely governed by their light absorption, separation of photoinduced charge carriers and surface catalytically active sites, which are primarily controlled by the morphology, crystalline size, structure, and especially the electronic structure of photocatalysts. Black TiO2 is recognized as one of the most promising visible-light photocatalysts, due to its significantly enhanced visible-light photocatalytic performance in comparison to intrinsic TiO2. In this work, black TiO2 is synthesized through the hydrogenation process...
May 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28530609/phenolic-compounds-of-the-australian-native-herb-prostanthera-rotundifolia-and-their-biological-activities
#13
Kitty S C Tang, Izabela Konczak, Jian Zhao
The chemical identity and bioactivities of phenolic components of the Australian native herb Prostanthera rotundifolia were studied. Phenolic compounds were extracted with 80% (v/v) aqueous methanol and purified by liquid chromatography. The antioxidant capacity of the extract and its inhibiting activity against α-glucosidase, pancreatic lipase and hyaluronidase were determined. Phenolic compounds were identified by a combination of HPLC-PDA, LC-high resolution MS (LC-HRMS), LC-tandem MS (LC-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy...
October 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28530541/synthesis-of-new-antibacterial-cubane-based-nanocomposite-and-its-application-in-combination-cancer-therapy
#14
Elham Zakerzadeh, Roya Salehi, Mehrdad Mahkam
BACKGROUND: The need for therapeutically effective anticancer drug delivery systems constantly persuades researchers to explore novel strategies. OBJECTIVE: In this study a novel cubane based antibacterial nanocomposite was tailored as dual chemotherapy drug delivery vesicle in order to increase the therapeutic outcome in cancer therapy. METHOD: The physico-chemical characterization of engineered nanocarrier was assessed by Fourier transforms infrared spectroscopy (FTIR), Hydrogen nuclear magnetic resonance spectroscopy (1H NMR), Thermogravimetric analysis (TGA), and Field emission scanning electron microscopy-energy dispersive using X-ray (FESEM-EDX)...
May 22, 2017: Anti-cancer Agents in Medicinal Chemistry
https://www.readbyqxmd.com/read/28528946/effects-of-different-durations-of-acid-hydrolysis-on-the-properties-of-starch-based-wood-adhesive
#15
Yajie Wang, Hanguo Xiong, Zhenjiong Wang, Zia-Ud-Din, Lei Chen
In this study, the effect of different durations of acid hydrolysis on the improvement of the properties of starch-based wood adhesive was investigated through a variety of determination methods The improved properties were analyzed using the pasting properties, viscosity, shear performance in dry and wet states, fourier infrared spectrometer, dynamic time sweep, and low filed nuclear magnetic resonance spectroscopy. Starch hydrolysis improved the viscosity stability, bonding performance, and water resistance of the starch-based wood adhesive...
May 18, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28527566/abnormalities-in-high-energy-phosphate-metabolism-in-first-episode-bipolar-disorder-measured-using-31-p-magnetic-resonance-spectroscopy
#16
Fei Du, Cagri Yuksel, Virginie-Anne Chouinard, Polly Huynh, Kyle Ryan, Bruce M Cohen, Dost Öngür
BACKGROUND: Brain energy metabolism is critical for supporting synaptic function and information processing. A growing body of evidence suggests abnormalities in brain bioenergetics in psychiatric disorders, including both bipolar disorder (BD) and schizophrenia. (31)P magnetic resonance spectroscopy provides a noninvasive window into these processes in vivo. Using this approach, we previously showed that patients with BD show normal adenosine triphosphate (ATP) and phosphocreatine levels at rest but cannot maintain normal ATP levels in the visual cortex during times of high energy demand (photic stimulation)...
April 7, 2017: Biological Psychiatry
https://www.readbyqxmd.com/read/28527462/low-power-broadband-solid-state-mas-nmr-of-14-n
#17
Andrew J Pell, Kevin J Sanders, Sebastian Wegner, Guido Pintacuda, Clare P Grey
We propose two broadband pulse schemes for (14)N solid-state magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) that achieves (i) complete population inversion and (ii) efficient excitation of the double-quantum spectrum using low-power single-sideband-selective pulses. We give a comprehensive theoretical description of both schemes using a common framework that is based on the jolting-frame formalism of Caravatti et al. [J. Magn. Reson. 55, 88 (1983)]. This formalism is used to determine for the first time that we can obtain complete population inversion of (14)N under low-power conditions, which we do here using single-sideband-selective adiabatic pulses...
May 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28527296/performances-and-working-mechanism-of-a-novel-polycarboxylate-superplasticizer-synthesized-through-changing-molecular-topological-structure
#18
Xiao Liu, Jianan Guan, Guanghong Lai, Ziming Wang, Jie Zhu, Suping Cui, Mingzhang Lan, Huiqun Li
A novel star-shaped polycarboxylate superplasticizer (SPCE) was synthesized through a simple two-step method. (1)H Nuclear Magnetic Resonance ((1)H NMR) and Infrared Spectroscopy (IR) measurements were used for structural characterization. SPCE and comb-shaped polycarboxylate superplasticizer (CPCE) with same molecular weights were designed and synthesized. The cement paste containing SPCE exhibited better fluidity, fluidity retention, water reduction, 25% lower saturated dosage of PCE, 10% longer setting time, lower hydration heat, more delayed hydration heat evolution and lower amount of hydration products at early ages...
May 10, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28527221/glutathione-conformations-and-its-implications-for-in-vivo-magnetic-resonance-spectroscopy
#19
Pravat K Mandal, Deepika Shukla, Varan Govind, Yves Boulard, Lars Ersland
Glutathione (GSH) is a major antioxidant in humans that is involved in the detoxification of reactive radicals and peroxides. The molecular structural conformations of GSH depend on the surrounding micro-environment, and it has been experimentally evaluated using NMR and Raman spectroscopic techniques as well as by molecular dynamics simulation studies. The converging report indicates that GSH exists mainly in two major conformations, i.e., "extended" and "folded". The NMR-derived information on the GSH conformers is essential to obtain optimal acquisition parameters in in vivo MRS experiments targeted for GSH detection...
May 17, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28526818/essential-hypertension-a-filtered-serum-based-metabolomics-study
#20
Keerti Ameta, Ashish Gupta, Sudeep Kumar, Rishi Sethi, Deepak Kumar, Abbas Ali Mahdi
Despite the easy and reliable methods of blood pressure measurement, the screening of essential hypertension (EH) is usually ignored due to delayed onset of symptoms. A probe into the biochemical changes in hypertension would serve as a welcome asset to provide insight into the mechanistic aspects of EH. Filtered serum samples from 64 EH patients and 59 healthy controls (HC) were analysed using 800 MHz nuclear magnetic resonance (NMR) spectroscopy. Application of principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) following receiver operating characteristic (ROC) curve of NMR data reveals significantly perturbed metabolites: alanine, arginine, methionine, pyruvate, adenine, and uracil...
May 19, 2017: Scientific Reports
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