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Journal articles on the topic '1H detection'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

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1

Kolen, Martin, Wilson A. Smith, and Fokko M. Mulder. "Accelerating 1H NMR Detection of Aqueous Ammonia." ACS Omega 6, no. 8 (February 19, 2021): 5698–704. http://dx.doi.org/10.1021/acsomega.0c06130.

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2

Fang, Cheng, Jinjian Wu, Zahra Sobhani, Md Al Amin, and Youhong Tang. "Aggregated-fluorescent detection of PFAS with a simple chip." Analytical Methods 11, no. 2 (2019): 163–70. http://dx.doi.org/10.1039/c8ay02382d.

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In this study, aggregation-induced emission luminogens (AIEgen) are used for the detection of per- and poly-fluoroalkyl substances (PFAS) including perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2FTS).

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3

Yamauchi, Jun, and Yasuo Deguchi. "1H and 14N ENDOR spectra of tert-butylphenylnitroxide." Canadian Journal of Chemistry 66, no. 8 (August 1, 1988): 1862–66. http://dx.doi.org/10.1139/v88-301.

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1H and 14N ENDOR spectra of tert-butylphenylnitroxide were observed in ethylbenzene solution. The experimental conditions for detecting optimum 1H and 14N ENDOR lines were quite different. The 1H hyperfine coupling constants and their signs are discussed from the viewpoints of molecular orbital calculations, general triple resonance, CRISP (cross relaxation intensity sequence pattern) method, and steric hindrance. In view of the large anisotropic hyperfine interaction between the nitrogen and the unpaired electron, detection of 14N ENDOR in nitroxide radicals is rather difficult, so that a TM110 mode cavity was utilized in this experiment. The observed 14N hyperfine coupling constant 11.86 G at −80 °C is one of the smallest values observed to date for nitroxide radicals.

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4

Furihata, Kazuo, and Mitsuru Tashiro. "Improved 19F{1H} Saturation Transfer Difference Experiments for Sensitive Detection to Fluorinated Compound Bound to Proteins." Magnetochemistry 5, no. 1 (December 21, 2018): 1. http://dx.doi.org/10.3390/magnetochemistry5010001.

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The 19F{1H} saturation transfer difference (STD) method was improved for sensitive 19F detection using a human serum albumin-diflunisal complex. Because NMR (nuclear magnetic resonance) experiments with 19F detection are feasible for the selective detection of fluorinated compounds, more sensitive NMR methods are required to be developed for purposes of practicality. The present research focused on the investigations of 19F{1H} STD pulse techniques and experimental parameters, leading to the development of detection methods with higher sensitivity.

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5

Reddy, Ravinder, Alan H. Stolpen, Sridhar R. Charagundla, E. K. Insko, and John S. Leigh. "17O-decoupled 1H detection using a double-tuned coil." Magnetic Resonance Imaging 14, no. 9 (January 1996): 1073–78. http://dx.doi.org/10.1016/s0730-725x(96)00227-5.

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6

Sklenář, VladimÍR, Dennis Torchia, and Ad Bax. "Measurement of carbon-13 longitudinal relaxation using 1H detection." Journal of Magnetic Resonance (1969) 73, no. 2 (June 1987): 375–79. http://dx.doi.org/10.1016/0022-2364(87)90214-9.

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7

Musa, Liyana, Sabrilhakim Sidek, Firdaus Yusof @ Alias, Mohammad Hanafiah, Azlan Azha Musa, and Mazuin Mohd Razalli. "Proton Magnetic Resonance Spectroscopy (1H-MRS) in Studies of Glaucoma: A Scoping Review." Science Letters 15, no. 2 (June 15, 2021): 135–46. http://dx.doi.org/10.24191/sl.v15i2.13835.

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Glaucoma is a disease that is chronic in nature and indistinctive at an early stage, leading to late detection. It has become a major public health problem and a leading cause of irreversible blindness worldwide. The proton magnetic resonance spectroscopy (1H-MRS), of late, has been utilised to evaluate metabolites concentration in the brain, especially for detecting neurodegenerative disease. Considering that glaucoma is a neurodegenerative disease, studies on the concentration of metabolites using 1H-MRS in glaucoma patients could be investigated. This scoping review aims to examine the extent, range, and nature of studies on the 1H-MRS technique in glaucoma disease. The literature search was conducted using MEDLINE, CINAHL and SCOPUS, dated from 2000 until 2019. Studies on glaucoma using 1H-MRS were considered. Any processing method used to characterise the metabolite concentration generated by the 1H-MRS protocol has also been considered. Nine full-text studies were yielded after hundreds of literature identification, screening, and eligibility assessment. The included studies sought to determine the feasibility, change, and comparability of metabolite concentrations in glaucoma patients using 1H-MRS with more studies utilising single-voxel spectroscopy (SVS) technique. The chosen anatomy of interest could have been influenced by several criteria, including the association between anatomy and the research query and the volume-sizing capabilities of the 1H-MRS technique. Six (6) metabolites were significantly identified, and quantified, including N-acetyl aspartate, Creatine, Choline, Myo-Inositol, Lactate and Glutamate-Glutamine. This scoping review points out the 1H-MRS application in different types and severity of glaucoma, highlighting the information on the type of patients, the detected metabolites in the anatomy involved, the 1H-MRS technique used and the raw data decipherment processing software. Future studies are needed to validate existing glaucoma studies and to explore the potential of detecting incipient glaucoma.

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8

Costa, Gabriel P. da, Diego Alves, and Márcio S. Silva. "Diethyl (2-(4-Phenyl-1H-1,2,3-triazol-1-yl)benzyl) Phosphate." Molbank 2021, no. 2 (June 1, 2021): M1223. http://dx.doi.org/10.3390/m1223.

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Here we describe a full structural elucidation of the diethyl (2-(4-phenyl-1H-1,2,3-triazol-1-yl)benzyl) phosphate. This compound is a common by-product present in the synthetic protocols to access the α-hydroxy phosphonate compounds through of a Phospha-Brook rearrangement. Thus, a complete NMR structural characterization of this rearrangement by-product was performed by 1H, 13C{1H}, 31P{1H}, COSY, HSQC, and HMBC NMR experiments. Additionally, we have demonstrated that the 1H-31P HMBC is a 2D heteroatom NMR experiment which combines the simple identification by 31P chemical shift with the detection sensitivity by 1H spectrum in a practical procedure.

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9

Schnell, Ingo, Benedikt Langer, Serge H. M. Söntjens, Marcel H. P. van Genderen, Rint P. Sijbesma, and Hans Wolfgang Spiess. "Inverse Detection and Heteronuclear Editing in 1H–15N Correlation and 1H–1H Double-Quantum NMR Spectroscopy in the Solid State under Fast MAS." Journal of Magnetic Resonance 150, no. 1 (May 2001): 57–70. http://dx.doi.org/10.1006/jmre.2001.2312.

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10

Cao, Cheng, Xingmei You, Lei Feng, Guanghong Luo, Guoren Yue, and Xiangdong Ji. "Synthesis of new chromogenic sensors containing thiourea and selective detection for F–, H2PO4–, and Ac– anions." Canadian Journal of Chemistry 98, no. 10 (October 2020): 659–66. http://dx.doi.org/10.1139/cjc-2020-0120.

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Two new chromogenic sensors 1-(2-hydroxyphenyl)-3-(4-nitrophenyl)thiourea 1 and 1-(3-hydroxypyridin-2-yl)-3-(4-nitrophenyl)thiourea 2 bearing nitrophenyl and thiourea groups were designed and synthesized by one-step procedure and characterized through 1H NMR, 13C NMR, FTIR, and MS. The anion recognition property of the receptors was studied via naked-eye detection, UV–vis, and 1H NMR. Based on the existence of amino gen and hydroxyl moieties in receptors, receptors 1 and 2 exhibit obvious selectivity by the redshift of UV–vis signals, colour changes through naked-eye detection, and binding effects for F–, H2PO4–, and Ac–. Surprisingly, the detection limits of receptor 1 for F– and Ac– were calculated to be 5.45 × 10−7 and 2.11 × 10−7 (mol/L)−1, respectively, which indicated that F– and Ac– can be identified with high sensitivity by receptor 1. Besides, simple “test strips” were developed and were used as sensors for recognition of F–, H2PO4–, or Ac– in DMSO solution. Lastly, the mechanisms of the recognition process were studied through DFT calculation and 1H NMR titration.

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11

Mao, Jiezhen, Ling Jiang, Bin Jiang, Maili Liu, and Xi-an Mao. "1H–14N HSQC detection of choline-containing compounds in solutions." Journal of Magnetic Resonance 206, no. 1 (September 2010): 157–60. http://dx.doi.org/10.1016/j.jmr.2010.06.003.

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12

Menshchikov, P. E., A. S. Ivantsova, T. A. Akhadov, M. V. Ublinskiy, A. V. Manzhurtsev, and N. A. Semenova. "1H MRS as a novel quantitative method for osteoporosis detection." Journal of Physics: Conference Series 1461 (March 2020): 012098. http://dx.doi.org/10.1088/1742-6596/1461/1/012098.

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13

Liu, T., T. M. Olajide, W. Wang, Z. Cheng, Q. Cheng, and X. C. Weng. "Quality detection of tea oil by 19F NMR and 1H NMR." Grasas y Aceites 72, no. 3 (September 24, 2021): e426. http://dx.doi.org/10.3989/gya.0662201.

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The nuclear magnetic resonance (NMR) technique was applied to monitor the quality of tea oil herein. The adulteration of virgin tea oil was monitored by 19F NMR and 1H NMR. The 19F NMR technique was used as a new method to detect the changes in quality and hydroperoxide value of tea oil. The research demonstrates that 19F NMR and 1H NMR can quickly detect adulteration in tea oil. High temperature caused a decrease in the ratio D and increase in the total diglyceride content. Some new peaks belonging to the derivatives of hydroperoxides appeared at δ-108.21 and δ-109.05 ppm on the 19F NMR spectrum when the oil was autoxidized and became larger when the hydroperoxide value increased. These results have great significance in monitoring the moisture content, freshness and oxidation status of oils and in detecting adulteration in high priced edible oils by mixing with cheap oils.

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14

Albiin, N., I. C. P. Smith, U. Arnelo, B. Lindberg, A. Bergquist, B. Dolenko, N. Bryksina, and T. Bezabeh. "Detection of cholangiocarcinoma with magnetic resonance spectroscopy of bile in patients with and without primary sclerosing cholangitis." Acta Radiologica 49, no. 8 (October 2008): 855–62. http://dx.doi.org/10.1080/02841850802220092.

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Background: Early detection of cholangiocarcinoma (CC) is very difficult, especially in patients with primary sclerosing cholangitis (PSC) who are at increased risk of developing CC. Purpose: To evaluate 1H magnetic resonance spectroscopy (1H-MRS) of bile as a diagnostic marker for CC in patients with and without PSC. Material and Methods: The institutional review board approved the study, and all patients gave informed consent. Bile from 49 patients was sampled and investigated using 1H-MRS. MR spectra of bile samples from 45 patients (18 female; age range 22–87 years, mean age 57 years) were analyzed both conventionally and using computerized multivariate analysis. Sixteen of the patients had CC, 18 had PSC, and 11 had other benign findings. Results: The spectra of bile from CC patients differed from the benign group in the levels of phosphatidylcholine, bile acids, lipid, and cholesterol. It was possible to distinguish CC from benign conditions in all patients with malignancy. Two benign non-PSC patients were misclassified as malignant. The sensitivity, specificity, and accuracy were 88.9%, 87.1%, and 87.8%, respectively. Conclusion: With 1H-MRS of bile, cholangiocarcinoma could be discriminated from benign biliary conditions with or without PSC.

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15

Casieri, C., A. Knijn, F. Podo, and F. De Luca. "1H NMR detection of 13C–1H bonds by double 13C editing: application to the discrimination of glucose metabolites." Chemical Physics Letters 338, no. 2-3 (April 2001): 137–41. http://dx.doi.org/10.1016/s0009-2614(01)00258-5.

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16

Yan, Chuanyu, François Kayser, and Reiner Dieden. "Sensitivity enhancement via multiple contacts in the {1H–29Si}–1H cross polarization experiment: a case study of modified silica nanoparticle surfaces." RSC Advances 10, no. 39 (2020): 23016–23. http://dx.doi.org/10.1039/d0ra04995f.

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In this paper we demonstrate {¹H–²⁹Si}–¹H multiple cross polarization inverse detection (MCPi) solid state NMR as a robust technique for studying modified silica nanoparticle surfaces.

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17

Breen, Leah E., Norman P. Schepp, and C.-H. Edmund Tan. "Photochemical generation and 1H NMR detection of alkyl allene oxides in solution." Canadian Journal of Chemistry 83, no. 9 (September 1, 2005): 1347–51. http://dx.doi.org/10.1139/v05-139.

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Irradiation of substituted 5-alkyl-4,5-epoxyvalerophenones leads to the formation of alkyl allene oxides that, in some cases, are sufficiently long-lived to be detected at room temperature by 1H NMR spectroscopy. Absolute lifetime measurements show that the size of the alkyl group has a significant influence on the reactivity of the allene oxide, with tert-butyl allene oxide having a lifetime of 24 h in CD3CN at room temperature that is considerably longer than the 1.5 h lifetime of the ethyl allene oxide. The allene oxides react rapidly with water to give α-hydroxyketones. The mechanism involves nucleophilic attack to the epoxide carbon to give an enol, which can also be detected as an intermediate by 1H NMR spectroscopy.Key words: allene oxides, mechanisms, absolute reactivity, kinetics, photochemistry.

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18

Shumilina, Elena, Christian Andreasen, Zahra Bitarafan, and Alexander Dikiy. "Determination of Glyphosate in Dried Wheat by 1H-NMR Spectroscopy." Molecules 25, no. 7 (March 28, 2020): 1546. http://dx.doi.org/10.3390/molecules25071546.

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A wheat field was sprayed with a dosage of 1.1 kg a.i./ha Roundup PowerMax 10 days before harvest. The 1H Nuclear Magnetic Resonance (NMR) spectroscopy was used for the detection and quantification of the glyphosate (GLYP) in dried wheat spikelets, leaves, and stems. The quantification was done by the integration of the CH2-P groups doublet at 3.00 ppm with good linearity. The GLYP content varied between different samples and parts of the plant. On average, the largest content of herbicide was found in leaves (20.0 mg/kg), followed by stems (6.4 mg/kg) and spikelets (6.3 mg/kg). Our study shows that the 1H-NMR spectroscopy can be a rapid and reliable tool for GLYP detection and quantification in the field studies.

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19

Kaiser, Lana G., Małgorzata Marjańska, Gerald B. Matson, Isabelle Iltis, Seth D. Bush, Brian J. Soher, Susanne Mueller, and Karl Young. "1H MRS detection of glycine residue of reduced glutathione in vivo." Journal of Magnetic Resonance 202, no. 2 (February 2010): 259–66. http://dx.doi.org/10.1016/j.jmr.2009.11.013.

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20

Higuchi, Makoto, Nobuhisa Iwata, Yukio Matsuba, Kumi Sato, Kazumi Sasamoto, and Takaomi C. Saido. "19F and 1H MRI detection of amyloid β plaques in vivo." Nature Neuroscience 8, no. 4 (March 13, 2005): 527–33. http://dx.doi.org/10.1038/nn1422.

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21

D’Emiliano, D., C. Casieri, M. Paci, and F. De Luca. "Detection of ganglioside clustering in DOPC bilayers by 1H-NMR spectroscopy." Physica A: Statistical Mechanics and its Applications 374, no. 1 (January 2007): 293–303. http://dx.doi.org/10.1016/j.physa.2006.07.021.

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22

Terpstra, Melissa, and Rolf Gruetter. "1H NMR detection of vitamin C in human brain in vivo." Magnetic Resonance in Medicine 51, no. 2 (2004): 225–29. http://dx.doi.org/10.1002/mrm.10715.

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23

Nakai, Toshiharu, Toshio Iijima, and Tomohisa Okada. "2808 Improvement of lactate detection by 1h double quantum coherence transfer." Neuroscience Research 25 (January 1996): S269. http://dx.doi.org/10.1016/0168-0102(96)89314-x.

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24

Hong, Mei, and Satoru Yamaguchi. "Sensitivity-Enhanced Static 15N NMR of Solids by 1H Indirect Detection." Journal of Magnetic Resonance 150, no. 1 (May 2001): 43–48. http://dx.doi.org/10.1006/jmre.2001.2309.

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25

Ciesielski, Witold, and Anna Krenc. "Potentiometric Titration of Triazolethiols and Tetrazolethiols with Iodine in Alkaline Medium." Collection of Czechoslovak Chemical Communications 67, no. 8 (2002): 1193–99. http://dx.doi.org/10.1135/cccc20021193.

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The iodimetric determination of triazolethiols and tetrazolethiols in alkaline medium is presented. The volumetric titration with potentiometric end-point detection was applied. The range of determination, in which the error is lower than 1%, is 20-2 000 μmol for 1H-1,2,4-triazole-3-thiol (1), 25-1 000 μmol for 3-phenyl-1H-1,2,4-triazole-5-thiol (2), 25-500 μmol for 4-methyl-5-(trifluoromethyl)-4H-1,2,4-triazole-3-thiol (3), 50-500 μmol for 3-amino-1H-1,2,4-triazole-5-thiol (4), 10-1 000 μmol for sodium (5-mercapto-1H-tetrazol-1-yl)acetate (5), 125-500 μmol for 1-phenyl-1H-tetrazole-5-thiol (6) and 50-1 000 μmol for 1-(4-hydroxyphenyl)-1H-tetrazole-5-thiol (7). The relative standard deviation for all determinations was below 1%. The shape of potentiometric titration curve of 6 and 7 is noteworthy at higher concentrations of sodium hydroxide and depends on the type of the indicator electrode (platinum, gold). An introduction of iodine results in a strong potential drop. Some systems do not follow the Nernst equation.

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26

Jiang, X. Y., C. Li, Q. Q. Chen, and X. C. Weng. "Comparison of ¹⁹F and ¹H NMR spectroscopy with conventional methods for the detection of extra virgin olive oil adulteration." Grasas y Aceites 69, no. 2 (June 4, 2018): 249. http://dx.doi.org/10.3989/gya.1221172.

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This paper reports the comparison of determination methods for extra virgin olive oil (EVOO) adulteration with two kinds of oils, refined olive oil (ROO) and soybean oil by 19FNMR, 1H NMR and chemical titration. The determination of adulteration of EVOO with ROO by 19F NMR was comparable to the conventional method. The contents of oleic, linoleic and linolenic acids of different oil samples can be determined by both 1H NMR and GC-MS. The results obtained from the two methods showed little differences. The adulteration of EVOO with soybean oil is detected by 1H NMR, although the limit of detection of the adulteration level is not less than 4.5%. The research demonstrates that 19F NMR can be a fast and convenient method to detect EVOO if it is adulterated with ROO and 1H NMR can be a fast and convenient method to detect EVOO if it is adulterated with seed oils.

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27

Yang, Lei, Feng Wang, Zhiwei Sun, Xiaojian Kong, and Yilin Kong. "Sensitive and selective detection of phosgene with a bis-(1H-benzimidazol-2-yl)-based turn-on fluorescent probe in the solution and gas phase." Analytical Methods 12, no. 24 (2020): 3123–29. http://dx.doi.org/10.1039/d0ay00404a.

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28

Tokunaga, Tatsuhiro, Hiroko Seki, Shuji Yasuike, Masaaki Ikoma, Jyoji Kurita, and Kentaro Yamaguchi. "Direct detection of intramolecular Sb···N nonbonded interaction by 1H–13C and 1H–15N heteronuclear multiple bond correlation spectroscopy." Tetrahedron Letters 41, no. 7 (February 2000): 1031–34. http://dx.doi.org/10.1016/s0040-4039(99)02189-9.

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29

Brüchwiler, Daniel, and Gerhard Wagner. "Selective excitation of 1H resonances coupled to 13C. hetero COSY and RELAY experiments with 1H detection for a protein." Journal of Magnetic Resonance (1969) 69, no. 3 (October 1986): 546–51. http://dx.doi.org/10.1016/0022-2364(86)90174-5.

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30

Al-Busafi, Saleh N., Salma M. Al-Kindi, Fakhr Eldin O. Suliman, and Aliya A. Al-Kalbani. "A Flavone Fluorescent Probe for Cysteine Detection." Asian Journal of Chemistry 31, no. 12 (November 16, 2019): 2909–14. http://dx.doi.org/10.14233/ajchem.2019.22286.

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A new blue-emitting fluorescent probe 1 based on flavone structure was prepared for the selective detection of cysteine. The probe was prepared through three synthetic steps from commercially available starting materials. Selective detection of cysteine by probe 1 in the presence of other non-thiol amino acids was established by UV-visible and fluorescent experiments. A remarkable fluorescence emission was observed at 469 nm when cysteine was mixed with probe 1. The Michael addition reaction of cysteine to probe-1 was confirmed by 1H NMR technique.

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31

Sharma, Uma, and Naranamangalam Raghunathan Jagannathan. "In vivo MR spectroscopy for breast cancer diagnosis." BJR|Open 1, no. 1 (July 2019): 20180040. http://dx.doi.org/10.1259/bjro.20180040.

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Breast cancer is a significant health concern in females, worldwide. In vivo proton (1H) MR spectroscopy (MRS) has evolved as a non-invasive tool for diagnosis and for biochemical characterization of breast cancer. Water-to-fat ratio, fat and water fractions and choline containing compounds (tCho) have been identified as diagnostic biomarkers of malignancy. Detection of tCho in normal breast tissue of volunteers and in lactating females limits the use of tCho as a diagnostic marker. Technological developments like high-field scanners, multi channel coils, pulse sequences with water and fat suppression facilitated easy detection of tCho. Also, quantification of tCho and its cut-off for objective assessment of malignancy have been reported. Meta-analysis of in vivo 1H MRS studies have documented the pooled sensitivities and the specificities in the range of 71–74% and 78–88%, respectively. Inclusion of MRS has been shown to enhance the diagnostic specificity of MRI, however, detection of tCho in small sized lesions (≤1 cm) is challenging even at high magnetic fields. Potential of MRS in monitoring the effect of chemotherapy in breast cancer has also been reported. This review briefly presents the potential clinical role of in vivo 1H MRS in the diagnosis of breast cancer, its current status and future developments.

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Robinson, Alastair, Peter Richardson, and Meghan Halse. "Hyperpolarised 1H–13C Benchtop NMR Spectroscopy." Applied Sciences 9, no. 6 (March 20, 2019): 1173. http://dx.doi.org/10.3390/app9061173.

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Benchtop NMR spectrometers with sub-ppm spectral resolution have opened up new opportunities for performing NMR outside of the standard laboratory environment. However, the relatively weak magnetic fields of these devices (1–2 T) results in low sensitivity and significant peak overlap in 1H NMR spectra. Here, we use hyperpolarised 13C{1H} NMR to overcome these challenges. Specifically, we demonstrate the use of the signal amplification by reversible exchange (SABRE) parahydrogen-based hyperpolarisation technique to enhance the sensitivity of natural abundance 1D and 2D 13C{1H} benchtop NMR spectra. We compare two detection methods for SABRE-enhanced 13C NMR and observe an optimal 13C{1H} signal-to-noise ratio (SNR) for a refocused INEPT approach, where hyperpolarisation is transferred from 1H to 13C. In addition, we exemplify SABRE-enhanced 2D 13C benchtop NMR through the acquisition of a 2D HETCOR spectrum of 260 mM of 4-methylpyridine at natural isotopic abundance in a total experiment time of 69 min. In theory, signal averaging for over 300 days would be required to achieve a comparable SNR for a thermally polarised benchtop NMR spectrum acquired of a sample of the same concentration at natural abundance.

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Zi, You, Hua Meng, Xue-Qiang Chu, Xiao-Ping Xu, and Shun-Jun Ji. "Synthesis and characterization on novel fluorescent sensors for Pd2+/Pd0 with high selectivity." RSC Advances 5, no. 33 (2015): 26092–96. http://dx.doi.org/10.1039/c5ra01343g.

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34

Ahmed, Naseer, Tedros Bezabeh, Omkar B. Ijare, Renelle Myers, Reem Alomran, Michel Aliani, Zoann Nugent, et al. "Metabolic Signatures of Lung Cancer in Sputum and Exhaled Breath Condensate Detected by 1H Magnetic Resonance Spectroscopy: A Feasibility Study." Magnetic Resonance Insights 9 (January 2016): MRI.S40864. http://dx.doi.org/10.4137/mri.s40864.

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Objectives Lung cancer is one of the most lethal cancers. Currently, there are no biomarkers for early detection, monitoring treatment response, and detecting recurrent lung cancer. We undertook this study to determine if 1H magnetic resonance spectroscopy (MRS) of sputum and exhaled breath condensate (EBC), as a noninvasive tool, can identify metabolic biomarkers of lung cancer. Materials and Methods Sputum and EBC samples were collected from 20 patients, comprising patients with pathologically confirmed non-small cell lung cancer ( n = 10) and patients with benign respiratory conditions ( n = 10). Both sputum and EBC samples were collected from 18 patients; 2 patients provided EBC samples only. 1H MR spectra were obtained on a Bruker Avance 400 MHz nuclear magnetic resonance (NMR) spectrometer. Sputum samples were further confirmed cytologically to distinguish between true sputum and saliva. Results In the EBC samples, median concentrations of propionate, ethanol, acetate, and acetone were higher in lung cancer patients compared to the patients with benign conditions. Median concentration of methanol was lower in lung cancer patients (0.028 mM) than in patients with benign conditions (0.067 mM; P = 0.028). In the combined sputum and saliva and the cytologically confirmed sputum samples, median concentrations of N-acetyl sugars, glycoprotein, propionate, lysine, acetate, and formate were lower in the lung cancer patients than in patients with benign conditions. Glucose was found to be consistently absent in the combined sputum and saliva samples (88%) as well as in the cytologically confirmed sputum samples (86%) of lung cancer patients. Conclusion Absence of glucose in sputum and lower concentrations of methanol in EBC of lung cancer patients discerned by 1H MRS may serve as metabolic biomarkers of lung cancer for early detection, monitoring treatment response, and detecting recurrence.

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35

Yang, Lan, Qian Li, Yanmei Feng, and Daiyu Qiu. "Simultaneous Determination of Three Coumarins in Angelica dahurica by 1H-qNMR Method: A Fast and Validated Method for Crude Drug Quality Control." Journal of Analytical Methods in Chemistry 2020 (March 24, 2020): 1–7. http://dx.doi.org/10.1155/2020/8987560.

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In this study, a quantitative 1H NMR method (1H-qNMR) for determining the contents of imperatorin, byakangelicin, and oxypeucedanin in A. dahurica in traditional Chinese medicine (TCM) has been established. Dried plant material was extracted exhaustively with methanol by an ultrasonication-assisted extraction method. The 1H-qNMR measurements were performed on a 600 -MHz spectrometer with hydroquinone as the internal standard reference in deuterated dimethyl sulfoxide (DMSO-d6) solvent. Quantification was carried out using the 1H resonance signals at 6.55 ppm for hydroquinone and 7.68, 7.38-7.39, and 6.38-6.39 ppm for imperatorin, byakangelicin, and oxypeucedanin, respectively. The linearity, limit of detection (LOD), limit of quantitation (LOQ), precision, reproducibility, stability, and recovery of the methodology were evaluated, and results were good. The newly developed method has been applied to determine the three coumarins in A. dahurica.

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36

Cen, Peipei, Chen Liang, Lijuan Duan, Meilin Wang, Danian Tian, and Xiangyu Liu. "A robust 3D In–MOF with an imidazole acid ligand as a fluorescent sensor for sensitive and selective detection of Fe3+ ions." New Journal of Chemistry 44, no. 37 (2020): 16076–81. http://dx.doi.org/10.1039/d0nj03793a.

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37

Pattaweepaiboon, Supak, Natchayapak Phiromphu, Narongpol Kaewchangwat, Khomson Suttisintong, and Weekit Sirisaksoontorn. "An indolino-spironaphthooxazine probe for colorimetric detection of ferric ions in drinking water." New Journal of Chemistry 45, no. 25 (2021): 11284–91. http://dx.doi.org/10.1039/d1nj01166a.

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The sensing performance of a novel indolino-spironaphthooxazine derivative (SPNO), 6′(3,4-dihydroisoquinolin-2(1H)-yl)-3,3-dimethyl-1-phenethylspiro[indoline-2,3′-naphtho[2,1-b][1,4]oxazine], was investigated for rapid colorimetric detection of ferric ions (Fe³⁺) in drinking water.

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38

Blankenberg, FG, RW Storrs, L. Naumovski, T. Goralski, and D. Spielman. "Detection of apoptotic cell death by proton nuclear magnetic resonance spectroscopy." Blood 87, no. 5 (March 1, 1996): 1951–56. http://dx.doi.org/10.1182/blood.v87.5.1951.1951.

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Abstract Cells undergoing apoptosis (programmed cell death) display profound morphologic and biochemical changes in the nucleus, cytoplasm, and plasma membrane. We have shown a direct temporal relationship between the onset of apoptosis in Jurkat T-cell lymphoblast cultures and a greater than two-fold increase in the signal intensity of the methylene resonance (at 1.3 ppm) as observed by proton nuclear magnetic resonance spectroscopy (1H NMR). The increase in the methylene resonance intensity was seen when apoptosis was induced by serum deprivation, glucocorticoid, and doxorubicin treatment but not in necrotic (nonapoptotic) cell death. We have found similar changes in a variety of other cell lines undergoing apoptosis including the Hut 78 T-cell leukemia, JY natural killer T-cell leukemia, Daudi B-cell lymphoma, HeLa, and 3T3 fibroblast cell lines. Furthermore, this spectral change was diminished in Bcl-2 overexpressing HL-60 cell cultures treated with doxorubicin, which were relatively resistant to apoptosis, as compared to apoptotic HL-60 cultures. 1H NMR spectroscopy therefore may be useful in detecting apoptotic cell death in vivo.

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39

Blankenberg, FG, RW Storrs, L. Naumovski, T. Goralski, and D. Spielman. "Detection of apoptotic cell death by proton nuclear magnetic resonance spectroscopy." Blood 87, no. 5 (March 1, 1996): 1951–56. http://dx.doi.org/10.1182/blood.v87.5.1951.bloodjournal8751951.

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Cells undergoing apoptosis (programmed cell death) display profound morphologic and biochemical changes in the nucleus, cytoplasm, and plasma membrane. We have shown a direct temporal relationship between the onset of apoptosis in Jurkat T-cell lymphoblast cultures and a greater than two-fold increase in the signal intensity of the methylene resonance (at 1.3 ppm) as observed by proton nuclear magnetic resonance spectroscopy (1H NMR). The increase in the methylene resonance intensity was seen when apoptosis was induced by serum deprivation, glucocorticoid, and doxorubicin treatment but not in necrotic (nonapoptotic) cell death. We have found similar changes in a variety of other cell lines undergoing apoptosis including the Hut 78 T-cell leukemia, JY natural killer T-cell leukemia, Daudi B-cell lymphoma, HeLa, and 3T3 fibroblast cell lines. Furthermore, this spectral change was diminished in Bcl-2 overexpressing HL-60 cell cultures treated with doxorubicin, which were relatively resistant to apoptosis, as compared to apoptotic HL-60 cultures. 1H NMR spectroscopy therefore may be useful in detecting apoptotic cell death in vivo.

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40

Wrackmeyer, Bernd, Roland Köster, and Günter Seidel. "Notizen: Tricarbonyliron Complexes - Observation of 13C(CO) NMR Signals via Polarization Transfer." Zeitschrift für Naturforschung B 50, no. 7 (July 1, 1995): 1127–29. http://dx.doi.org/10.1515/znb-1995-0726.

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Improvements in the detection of 13C(CO) resonances by using polarization transfer techniques, based on long-range coupling constants nJ(13C(CO)1H) = 1 ±0.1 Hz (n > 3), are reported. Coupling constants between 13C(CO) and other rare spin-1/2 nuclei have been observed, and longrange 13C(CO)-1H coupling have been traced by two-dimensional (2D ) 13C/1H heteronuclear shift correlations (HETCOR). Seven tricarbonyliron complexes 1 to 5 serve as examples in which the [Fe(CO)3] fragment is linked to cyclic dienes (siloles: 1a, b; 1,1′-spirobisilole: 2), and to cyclic heterodienes derived from substituted 2,5-dihydro- 2,5-silaboroles [1-aza (3a, b); 1-thia (4); 1-selena (5)]. In the case of complex 5, it was possible to resolve the 77Se satellites with 2J( 77Se13C(CO )) = 4.4 Hz. In 2D 13C (CO )/1H HETCOR experiments it was shown that polarization transfer originates mainly from C-methyl groups [4J( 13C(CO)/1H (M ))], adjacent to the “terminal” carbon atom(s) of the cyclic diene or heterodiene system which are linked to the [Fe(CO)3] fragment.

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Owusu-Sarfo, K., V. Asiago, N. Gowda, N. Shanaiah, B. Xi, E. G. Chiorean, and D. Raftery. "1H NMR–based metabolic profiling of serum for the detection of pancreatic cancer." Journal of Clinical Oncology 29, no. 4_suppl (February 1, 2011): 193. http://dx.doi.org/10.1200/jco.2011.29.4_suppl.193.

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193 Background: Pancreatic cancer (PC) is one of the leading causes of cancer deaths with a 5-yr mortality rate of 95%, and the lack of a suitable early detection method contributes to its poor prognosis. Metabolomics, the analysis of the metabolic profiles in biological samples such as serum and urine is emerging as an important tool to complement other “omic” techniques. In an effort to identify potential biomarkers for PC, we analyzed serum from PC patients (pts) focusing on altered metabolic profiles using 1H nuclear magnetic resonance (NMR). Methods: The metabolite profiles from serum samples consisting of 55 PC pts and 32 healthy controls were analyzed using NMR combined with advanced supervised and unsupervised multivariate statistical methods such as partial least squares discriminant analysis (PLSDA) and principal component analysis (PCA). A number of metabolite markers selected based on p values and logistic regression rank the importance of each potential marker. Statistically significant metabolites between cancer and controls were used to build a prediction model. Results: Based on multivariate logistic regression analysis of 20 targeted metabolites, 10 metabolite markers were selected from the variable selection process and used to build a regression model with high accuracy (AUROC >0.99), a sensitivity of 95% and specificity of 95% using a training set of samples. When the model was tested on an independent set of patient samples, it yielded a sensitivity of 95% and a specificity of 100% (AUROC >0.98). Box and whisker plots for individual markers verified the high performance of all 10 markers. Conclusions: The high sensitivity of the metabolic profile that distinguishes PC pts from controls indicates the potential utility of 1H NMR metabolic profiling for the early detection of PC. The investigation has identified perturbations in several pathways such as glycolysis and amino acid metabolism, highlighting their contribution to disease onset. This study demonstrates the potential of metabolite profiling as an important tool toward detecting PC development. Future studies will involve metabolite validation on high risk pts, and additional mass spectrometry based metabolic discovery efforts. No significant financial relationships to disclose.

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Staneva, Desislava, Silvia Angelova, and Ivo Grabchev. "Spectral Characteristics and Sensor Ability of a New 1,8-Naphthalimide and Its Copolymer with Styrene." Sensors 20, no. 12 (June 21, 2020): 3501. http://dx.doi.org/10.3390/s20123501.

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In this study, a novel 6-(allylamino)-2-(2-(dimethylamino)ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NI3) was synthesized and characterized. Its copolymer with styrene was also obtained. The photophysical characteristics of NI3 were investigated in organic solvents and the results were compared with those of its structural analogue, 2-allyl-6-((2-(dimethylamino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NI4). The influences of the pH in the medium and different metal ions on the fluorescent intensity of monomers and polymers were also investigated. Computational tools (DFT and TDDFT calculations) were employed when studying the structure and properties of the 1,8-naphthalimide-based chromophores. Although the position of the N,N-dimethylaminoethylamine receptor fragment did not significantly impact proton detection, it was still important for detecting metal ion sensor ability, especially for monomeric 1,8-naphthalimide structures and their copolymers with styrene.

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Chhabra, Sandeep, Patrick Fischer, Koh Takeuchi, Abhinav Dubey, Joshua J. Ziarek, Andras Boeszoermenyi, Daniel Mathieu, et al. "15N detection harnesses the slow relaxation property of nitrogen: Delivering enhanced resolution for intrinsically disordered proteins." Proceedings of the National Academy of Sciences 115, no. 8 (February 5, 2018): E1710—E1719. http://dx.doi.org/10.1073/pnas.1717560115.

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Studies over the past decade have highlighted the functional significance of intrinsically disordered proteins (IDPs). Due to conformational heterogeneity and inherent dynamics, structural studies of IDPs have relied mostly on NMR spectroscopy, despite IDPs having characteristics that make them challenging to study using traditional 1H-detected biomolecular NMR techniques. Here, we develop a suite of 3D 15N-detected experiments that take advantage of the slower transverse relaxation property of 15N nuclei, the associated narrower linewidth, and the greater chemical shift dispersion compared with those of 1H and 13C resonances. The six 3D experiments described here start with aliphatic 1H magnetization to take advantage of its higher initial polarization, and are broadly applicable for backbone assignment of proteins that are disordered, dynamic, or have unfavorable amide proton exchange rates. Using these experiments, backbone resonance assignments were completed for the unstructured regulatory domain (residues 131–294) of the human transcription factor nuclear factor of activated T cells (NFATC2), which includes 28 proline residues located in functionally important serine–proline (SP) repeats. The complete assignment of the NFATC2 regulatory domain enabled us to study phosphorylation of NFAT by kinase PKA and phosphorylation-dependent binding of chaperone protein 14-3-3 to NFAT, providing mechanistic insight on how 14-3-3 regulates NFAT nuclear translocation.

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West, Sheldon D., and Edgar W. Day. "Liquid Chromatographic Determination of Fluridone Aquatic Herbicide and Its Metabolite in Fish and Crayfish." Journal of AOAC INTERNATIONAL 69, no. 5 (September 1, 1986): 856–59. http://dx.doi.org/10.1093/jaoac/69.5.856.

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Abstract A residue method is described for determination of the aquatic herbicide fluridone (1-methy1-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)- pyridinone) and its metabolite (1-methy1-3-(4-hydroxyphenyl)-5-[3- (trifluoromethyl)phenyl]-4(1H)-pyridinone) in fish and crayfish tissues. Both compounds are extracted from tissues with methanol, and the extracts are subjected to acidic hydrolysis to release conjugated forms of fluridone and the metabolite. Sample extracts are purified by liquidliquid partitioning and Florisil Sep-Pak® column chromatography. Both compounds are separated and measured by reverse phase liquid chromatography with UV detection at 313 nm. In the absence of interfering peaks, the method has a detection limit of approximately 0.04 ppm of either compound. Overall, recoveries averaged 96% for fluridone and 78% for the metabolite for all tissue types combined.

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ISHIBASHI, Yushi, Reiko SUEYOSHI, Tomoka MORITA, Atsushi YOSHIMURA, and Mari IWAYA-INOUE. "Detection of Pre-Harvest Sprouting in Rice Seeds by Using 1H-NMR." Environment Control in Biology 43, no. 2 (2005): 131–37. http://dx.doi.org/10.2525/ecb.43.131.

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Amiot, Aurelien, Anthony C. Dona, Anisha Wijeyesekera, Christophe Tournigand, Isabelle Baumgaertner, Yann Lebaleur, Iradj Sobhani, and Elaine Holmes. "1H NMR Spectroscopy of Fecal Extracts Enables Detection of Advanced Colorectal Neoplasia." Journal of Proteome Research 14, no. 9 (August 7, 2015): 3871–81. http://dx.doi.org/10.1021/acs.jproteome.5b00277.

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47

Li, Ting, Yong Liao, Xiaoyan Jiang, Di Mu, Xiandeng Hou, Chunchun Zhang, and Pengchi Deng. "pH detection in biological samples by 1D and 2D 1H–31P NMR." Talanta 178 (February 2018): 538–44. http://dx.doi.org/10.1016/j.talanta.2017.09.085.

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Schroeder, T. Benjamin, Constantin Job, Michael F. Brown, Richard S. Glass, Niannian You, and Eric Block. "1H-{125Te} indirect detection in nuclear magnetic resonance spectra of organotellurium compounds." Magnetic Resonance in Chemistry 35, no. 11 (November 1997): 752–56. http://dx.doi.org/10.1002/(sici)1097-458x(199711)35:11<752::aid-omr167>3.0.co;2-v.

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Sijens, Paul E., Peter C. Levendag, Charles J. Vecht, Pieter van Dijk, and Matthijs Oudkerk. "1H MR Spectroscopy Detection of Lipids and Lactate in Metastatic Brain Tumors." NMR in Biomedicine 9, no. 2 (April 1996): 65–71. http://dx.doi.org/10.1002/(sici)1099-1492(199604)9:2<65::aid-nbm397>3.0.co;2-n.

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Nolte, Markus, Alexei Privalov, Jürgen Altmann, Vladimir Anferov, and Franz Fujara. "1H-14N cross-relaxation in trinitrotoluene - a step toward improved landmine detection." Journal of Physics D: Applied Physics 35, no. 9 (April 18, 2002): 939–42. http://dx.doi.org/10.1088/0022-3727/35/9/317.

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