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Magnetic Nuclear Resonance

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https://www.readbyqxmd.com/read/29779258/hyperpolarized-porous-silicon-nanoparticles-potential-theragnostic-material-for-%C3%A2-%C3%A2-si-magnetic-resonance-imaging
#1
Hyeonglim Seo, Ikjang Choi, Nicholas Whiting, Jingzhe Hu, Quy Son Luu, Shivanand Pudakalakatti, Caitlin McCowan, Yaewon Kim, Niki Zacharias, Seunghyun Lee, Pratip Bhattacharya, Youngbok Lee
Porous silicon nanoparticles have recently garnered attention as potentially-promising biomedical platforms for drug delivery and medical diagnostics. Here, we demonstrate porous silicon nanoparticles as contrast agents for ²⁹Si magnetic resonance imaging. Size-controlled porous silicon nanoparticles were synthesized by magnesiothermic reduction of silica nanoparticles and were surface activated for further functionalization. Particles were hyperpolarized via dynamic nuclear polarization to enhance their ²⁹Si MR signals; the particles demonstrated long ²⁹Si spin-lattice relaxation (T₁) times (~ 25 mins), which suggests potential applicability for medical imaging...
May 20, 2018: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/29778843/a-synbiotic-improves-the-immunity-of-white-shrimp-litopenaeus-vannamei-metabolomic-analyses-reveal-compelling-evidence
#2
Truong-Giang Huynh, Ann-Chang Cheng, Chia-Chun Chi, Kuo-Hsun Chiu, Chun-Hung Liu
In this study, we examined the synergistic effects of a diet-administered synbiotic comprising galactooligosaccharide (GOS) and the probiotic Lactobacillus plantarum 7-40 on immune responses, immune-related gene expressions, and disease resistance to Vibrio alginolyticus in white shrimp Litopenaeus vannamei. To unravel the regulatory role of the synbiotic in activating the immune system of shrimp, 1 H nuclear magnetic resonance (NMR)-based metabolomic analyses were used to investigate hepatopancreas metabolites, then significantly altered metabolites were confirmed in both the hepatopancreas and plasma by reverse-phase high-performance liquid chromatography (RP-HPLC) and spectrophotometric analyses...
May 17, 2018: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/29778812/ameliorative-effects-of-boron-on-aluminum-induced-variations-of-cell-wall-cellulose-and-pectin-components-in-trifoliate-orange-poncirus-trifoliate-l-raf-rootstock
#3
Lei Yan, Muhammad Riaz, Xiuwen Wu, Chenqing Du, Yalin Liu, Cuncang Jiang
Aluminum (Al) phytotoxicity is a major limitation in the production of crops in the soils with pH ≤ 5. Boron (B) is indispensable nutrient for the development of higher plants and B role has been reported in the alleviation Al toxicity. Trifoliate orange rootstock was grown in two B and two Al concentrations. The results of the present study showed that Al toxicity adversely inhibited root elongation and exhibited higher oxidative stress in terms of H2 O2 and O2 - under B-deficiency. Additionally, the X-ray diffraction (XRD) analysis confirmed the increase of the cellulose crystallinity in the cell wall (CW)...
May 17, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29778707/synthesis-spectroscopic-single-crystal-diffraction-and-potential-nonlinear-optical-properties-of-novel-pyrazoline-derivatives-interplay-of-experimental-and-computational-analyses
#4
Muhammad Nadeem Arshad, Abdulhadi Salih Birinji, Muhammad Khalid, Abdullah M Asiri, Khalid A Al-Amry, Faisal M S Aqlan, Ataualpa A C Braga
Pyrazoline are widely being studied due to their potential applications in chemical field. Herein, five pyrazolines compounds were synthesized and characterized spectroscopically using nuclear magnetic resonance techniques (1 H NMR &13 C NMR) to determine the structures of molecules along-with UV-Visible and infrared (FT-IR) studies for additional spectroscopic support in characterization of entitle synthesized molecules. Unit cells, specific space groups, bond lengths, bond angles and hydrogen bonding interactions were determined by the x-ray diffraction studies...
May 16, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29778692/two-dimensional-distribution-measurement-of-electric-current-generated-in-a-polymer-electrolyte-fuel-cell-using-49-nmr-surface-coils
#5
Kuniyasu Ogawa, Tatsuyoshi Sasaki, Shigeki Yoneda, Kumiko Tsujinaka, Ritsuko Asai
In order to increase the current density generated in a PEFC (polymer electrolyte fuel cell), a method for measuring the spatial distribution of both the current and the water content of the MEA (membrane electrode assembly) is necessary. Based on the frequency shifts of NMR (nuclear magnetic resonance) signals acquired from the water contained in the MEA using 49 NMR coils in a 7 × 7 arrangement inserted in the PEFC, a method for measuring the two-dimensional spatial distribution of electric current generated in a unit cell with a power generation area of 140 mm × 160 mm was devised...
May 17, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29778604/structural-basis-for-the-interaction-of-mutasome-assembly-factor-rev1-with-ubiquitin
#6
Gaofeng Cui, Maria Victoria Botuyan, Georges Mer
REV1 is an evolutionarily conserved Translesion synthesis (TLS) DNA polymerase and an assembly factor key for the recruitment of other TLS polymerases to DNA damage sites. REV1-mediated recognition of ubiquitin in the proliferative cell nuclear antigen (PCNA) is thought to be the trigger for TLS activation. Here we report the solution nuclear magnetic resonance (NMR) structure of a 108-residue fragment of human REV1 encompassing the two putative ubiquitin-binding motifs UBM1 and UBM2 in complex with ubiquitin...
May 17, 2018: Journal of Molecular Biology
https://www.readbyqxmd.com/read/29778072/nmr-at-pressures-up-to-90-gpa
#7
Thomas Meier, Saiana Khandarkhaeva, Sylvain Petitgirard, Thomas Körber, Alexander Lauerer, Ernst Rössler, Leonid Dubrovinsky
The past 15 years have seen an astonishing increase in Nuclear Magnetic Resonance (NMR) sensitivity and accessible pressure range in high-pressure NMR experiments, owing to a series of new developments of NMR spectroscopy applied to the diamond anvil cell (DAC). Recently, with the application of electro-magnetic lenses, so-called Lenz lenses, in toroidal diamond indenter cells, pressures of up to 72 GPa with NMR spin sensitivities of about 1012  spin/Hz1/2 has been achieved. Here, we describe the implementation of a refined NMR resonator structure using a pair of double stage Lenz lenses driven by a Helmholtz coil within a standard DAC, allowing to measure sample volumes as small as 100 pl prior to compression...
May 14, 2018: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/29778068/evaluation-of-the-structural-morphology-of-starch-graft-poly-acrylic-acid-on-its-scale-inhibition-efficiency
#8
Wei Yu, Yawen Wang, Aimin Li, Hu Yang
The development of phosphorus-free and biodegradable scale inhibitors has been paid considerable attention. Two series of starch-graft-poly(acrylic acid) (St-g-PAA) samples with different grafting ratios and grafted-chain distributions, that is, the number and length of grafted PAA chains on the starch backbone, were designed and prepared in this study. Fourier transform infrared and 1 H nuclear magnetic resonance spectra were used to further characterize the molecular structures of the St-g-PAAs. In addition to dose, the effects of the structural morphologies of St-g-PAA, namely, grafting ratio and grafted-chain distribution, on the scale-inhibition performance against calcium carbonate were investigated systematically...
April 9, 2018: Water Research
https://www.readbyqxmd.com/read/29777128/comparison-of-the-serum-metabolic-signatures-based-on-1-h-nmr-between-patients-and-a-rat-model-of-deep-vein-thrombosis
#9
Jie Cao, Qian-Qian Jin, Gui-Ming Wang, Hong-Lin Dong, Yong-Ming Feng, Jun-Sheng Tian, Ke-Ming Yun, Ying-Yuan Wang, Jun-Hong Sun
Deep vein thrombosis (DVT) and pulmonary embolism (PE) have high morbidity, reduce quality of life, and can cause death. Biomarkers or genetic risk factors have not been identified in patients with DVT. In present study, serum of 61 patients suffering from DVT and a rat DVT model (n = 10) were assayed by a proton nuclear magnetic resonance (1 H NMR) metabolomics technique combing with multivariate statistical analysis to identify the metabolites. The MetPA platform was used to identify differences in the metabolic pathways between the rat model and patients...
May 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29775883/hydrolysis-and-recycling-of-urea-formaldehyde-resin-residues
#10
Ming Liu, Yan Wang, Yiqiang Wu, Hui Wan
Urea formaldehyde (UF) resin residues generate many poisonous chemicals during traditional disposal technologies for organic hazardous wastes. In this study, hydrothermal hydrolysis was developed to decompose, remove, and recycle cured UF resin. Under 140 °C and 2 h of hydrothermal process, 20 mL of either 2 M HCl or 30 w.t. % of formaldehyde solutions can decompose as much as 1.7 g of cured UF resin. In addition, from the attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), gas chromatography-mass spectroscopy (GCMS), X-ray diffraction (XRD), and 1 H nuclear magnetic resonance (NMR) analyses, it confirmed that the hydrothermal hydrolysis could hydrolyze cured UF resin...
May 15, 2018: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/29775727/isolation-structure-elucidation-and-antibacterial-activity-of-methyl-4-8-dimethylundecanate-from-the-marine-actinobacterium-streptomyces-albogriseolus-ecr64
#11
Durairaj Thirumurugan, Ramasamy Vijayakumar, Chithravel Vadivalagan, Pushparaj Karthika, Md Khurshid Alam Khan
Around 120 actinobacterial colonies were isolated from various regions of marine East coast region of Tamil Nadu, India. Among them, 33 were morphologically distinct and they were preliminarily screened for their antibacterial activity against Pseudomonas fluorescens, Vibrio cholerae, V. parahaemolyticus, V. alginolyticus, and Aeromonas hydrophila by cross-streak plate technique. Among the isolated, the isolate ECR64 exhibited maximum zone of inhibition against fish pathogenic bacteria. The crude bioactive compounds were extracted from the isolate ECR64 using different organic solvents which exhibited maximum antibacterial activity...
May 15, 2018: Microbial Pathogenesis
https://www.readbyqxmd.com/read/29775537/amplification-of-dynamic-nuclear-polarization-at-200-ghz-by-arbitrary-pulse-shaping-of-the-electron-spin-saturation-profile
#12
Ilia Kaminker, Songi Han
Dynamic nuclear polarization (DNP) takes center stage in nuclear magnetic resonance (NMR) as a tool to amplify its signal by orders of magnitude through the transfer of polarization from electron to nuclear spins. In contrast to modern NMR and electron paramagnetic resonance (EPR) that extensively rely on pulses for spin manipulation in the time domain, the current mainstream DNP technology exclusively relies on monochromatic continuous wave (CW) irradiation. This study introduces arbitrary phase shaped pulses that constitute a train of coherent chirp pulses in the time domain at 200 GHz (7 Tesla) to dramatically enhance the saturation bandwidth and DNP performance compared to CW DNP, yielding up to 500-fold in NMR signal enhancements...
May 18, 2018: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29775343/observation-of-discrete-time-crystal-signatures-in-an-ordered-dipolar-many-body-system
#13
Jared Rovny, Robert L Blum, Sean E Barrett
A discrete time crystal (DTC) is a robust phase of driven systems that breaks the discrete time translation symmetry of the driving Hamiltonian. Recent experiments have observed DTC signatures in two distinct systems. Here we show nuclear magnetic resonance observations of DTC signatures in a third, strikingly different system: an ordered spatial crystal. We use a novel DTC echo experiment to probe the coherence of the driven system. Finally, we show that interactions during the pulse of the DTC sequence contribute to the decay of the signal, complicating attempts to measure the intrinsic lifetime of the DTC...
May 4, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29775316/l-arginine-catalyzed-synthesis-of-nanometric-organosilica-particles-through-a-waterborne-sol-gel-process-and-their-porous-structure-analysis
#14
Xiaoguang Qiao, Pierre-Yves Dugas, Laurent Veyre, Elodie Bourgeat-Lami
We report an efficient and easy to implement waterborne sol-gel process for the synthesis of nanometric organosilica particles. In this process, tetraethyl orthosilicate (TEOS) and 3-(methacryloxy)propyl trimethoxy silane (γ-MPS), employed as silica sources, are heterogeneously delivered in an aqueous solution of L-arginine, a basic amino acid used as catalyst, from a top organic layer. Co-condensation of TEOS with γ-MPS led to organosilica particles with diameters comprised between 30 and 230 nm when increasing the γ-MPS content from 0 to 10...
May 18, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29774643/a-nona-nuclear-heterometallic-pd3pt6-donut-shaped-cage-molecular-recognition-and-photocatalysis
#15
Dan Preston, Keith C Gordon, Joshua J Sutton, James D Crowley
We report a simple, low symmetry 2-(1-(pyridine-4-methyl)-1H-1,2,3-triazol-4-yl)pyridine ligand which has both monodentate and bidentate binding sites. With platinumII and/or palladiumII ions, two examples of a new nona-nuclear metallo-assembly have been accessed. These complexes have been characterized by nuclear magnetic resonance (NMR) spectroscopies, electrospray mass spectrometry (ESI-MS), and in key cases, X-ray crystallography. The cages possess three clefts comprised of planar cationic panels. This structural feature enables the binding of planar aromatic guests such as anthracene...
May 18, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29773403/synthesis-of-chitin-glucan-aldehyde-quercetin-conjugate-and-evaluation-of-anticancer-and-antioxidant-activities
#16
Anu Singh, P K Dutta, Hridyesh Kumar, Amit Kumar Kureel, Ambak Kumar Rai
In the present study, we have synthesized chitin-glucan-aldehyde-quercetin (chi-glu-ald-que) conjugate via condensation reaction. Synthesis of chitin-glucan-aldehyde (chi-glu-ald) complex was facilitated by the oxidation of chitin-glucan (chi-glu) complex. Formation of conjugate was confirmed by Proton nuclear magnetic resonance spectroscopy (1 H NMR) and Fourier-transform infrared spectroscopy (FT-IR). Morphological studies showed that after grafting of quercetin, several changes on surface were depicted and a more crystalline nature was observed...
August 1, 2018: Carbohydrate Polymers
https://www.readbyqxmd.com/read/29773375/characterization-and-prebiotic-activity-in-vitro-of-inulin-type-fructan-from-codonopsis-pilosula-roots
#17
Yu-Ping Fu, Li-Xia Li, Bing-Zhao Zhang, Berit Smestad Paulsen, Zhong-Qiong Yin, Chao Huang, Bin Feng, Xing-Fu Chen, Ren-Rong Jia, Xu Song, Xue-Qin Ni, Bo Jing, Fa-Ming Wu, Yuan-Feng Zou
The inulin-type fructan was obtained by DEAE anion exchange chromatography from C. pilosula Nannf. var. modesta (Nannf.) L. T. Shen, after optimized extract condition, which was established by response surface methodology, designed using Box-Behnken factorial design and the optimum condition were: extracting 2.5 h with ratio of solvent to material 40 mL/g at 100 °C, twice. The maximum extraction yield was 20.6 ± 0.2%. It was confirmed as β-(2-1) linkage fructan, with terminal glucose, and with a degree of polymerization of 2-17 (DPav  = 6), shown by the results of methanolysis, methylation, nuclear magnetic resonance and molecular weight determination...
August 1, 2018: Carbohydrate Polymers
https://www.readbyqxmd.com/read/29773374/electrospinning-and-wound-healing-activity-of-%C3%AE-chitin-extracted-from-cuttlefish-bone
#18
Hyeong-Seop Jung, Min Hee Kim, Ji Youn Shin, Se Ra Park, Ju-Young Jung, Won Ho Park
A nanofibrous β-chitin web was fabricated via electrospinning for use as a novel wound dressing material. β-chitin was extracted from cuttlefish bone using deproteinization and demineralization. First, cuttlefish bone was alkali-treated to remove the proteins and was then treated with the acid for demineralization. The extracted β-chitin was dissolved in formic acid as solvent to evaluate its electrospinnability, and the electrospinnability increased remarkably when β-chitin was blended with poly(ethylene oxide) (PEO) than without...
August 1, 2018: Carbohydrate Polymers
https://www.readbyqxmd.com/read/29773364/homogeneous-synthesis-of-cellulose-acrylate-g-poly-n-alkyl-acrylate-solid-solid-phase-change-materials-via-free-radical-polymerization
#19
Yong-Qiang Qian, Na Han, Yi-Wen Bo, Lin-Li Tan, Long-Fei Zhang, Xing-Xiang Zhang
A novel solid-solid phase change materials, namely, cellulose acrylate-g-poly (n-alkyl acrylate) (CA-g-PAn) (n = 14, 16 and 18) were successfully synthesized by free radical polymerization in N, N-dimethylacetamide (DMAc). The successful grafting was confirmed by fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (NMR). The properties of the CA-g-PAn copolymers were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The phase change temperatures and the melting enthalpies of CA-g-PAn copolymers are in the range of 10...
August 1, 2018: Carbohydrate Polymers
https://www.readbyqxmd.com/read/29773004/anti-inflammatory-activity-of-chemical-constituents-isolated-from-the-willow-bracket-medicinal-mushroom-phellinus-igniarius-agaricomycetes
#20
Zhe Jiang, Mei Jin, Wei Zhou, Ren Li, Yan Zhao, Xuejun Jin, Gao Li
Nuclear factor-κB (NF-κB) has an important role in immune response and inflammation. Phellinus igniarius (known as Sang huang in traditional Chinese medicine) has various pharmacologic effects. In this study, 19 chemical constituents (1-19) were isolated from the fruiting bodies of Ph. igniarius. Their structures were elucidated based on data from nuclear magnetic resonance spectroscopy and comparison with the literature. Overall, 3 compounds (2, 7, and 11) from this species were reported, to our knowledge for the first time...
2018: International Journal of Medicinal Mushrooms
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