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[PMID]:28742053
[Au] Autor:Lehrack S; Assmann W; Bertrand D; Henrotin S; Herault J; Heymans V; Stappen FV; Thirolf PG; Vidal M; Van de Walle J; Parodi K
[Ad] Endereço:Department of Medical Physics, Ludwig-Maximilians-Universität München, 85748 Garching b. München, Germany.
[Ti] Título:Submillimeter ionoacoustic range determination for protons in water at a clinical synchrocyclotron.
[So] Source:Phys Med Biol;62(17):L20-L30, 2017 Aug 18.
[Is] ISSN:1361-6560
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Proton ranges in water between 145 MeV to 227 MeV initial energy have been measured at a clinical superconducting synchrocyclotron using the acoustic signal induced by the ion dose deposition (ionoacoustic effect). Detection of ultrasound waves was performed by a very sensitive hydrophone and signals were stored in a digital oscilloscope triggered by secondary prompt gammas. The ionoacoustic range measurements were compared to existing range data from a calibrated range detector setup on-site and agreement of better than 1 mm was found at a Bragg peak dose of about 10 Gy for 220 MeV initial proton energy, compatible with the experimental errors. Ionoacoustics has thus the potential to measure the Bragg peak position with submillimeter accuracy during proton therapy, possibly correlated with ultrasound tissue imaging.
[Mh] Termos MeSH primário: Acústica
Ciclotrons/instrumentação
Terapia com Prótons
Prótons/uso terapêutico
Água/química
[Mh] Termos MeSH secundário: Calibragem
Seres Humanos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Protons); 059QF0KO0R (Water)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170726
[St] Status:MEDLINE
[do] DOI:10.1088/1361-6560/aa81f8


  2 / 1162 MEDLINE  
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[PMID]:28443689
[Au] Autor:Boschi A; Martini P; Pasquali M; Uccelli L
[Ad] Endereço:a Department of Morphology, Surgery and Experimental Medicine , University of Ferrara , Italy.
[Ti] Título:Recent achievements in Tc-99m radiopharmaceutical direct production by medical cyclotrons.
[So] Source:Drug Dev Ind Pharm;43(9):1402-1412, 2017 Sep.
[Is] ISSN:1520-5762
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Tc is the most commonly used radionuclide in the field of diagnostic imaging, a noninvasive method intended to diagnose a disease, assess the disease state and monitor the effects of treatments. Annually, the use of Tc, covers about 85% of nuclear medicine applications. This isotope releases gamma rays at about the same wavelength as conventional X-ray diagnostic equipment, and owing to its short half-life (t = 6 h) is ideal for diagnostic nuclear imaging. A patient can be injected with a small amount of Tc and within 24 h almost 94% of the injected radionuclide would have decayed and left the body, limiting the patient's radiation exposure. Tc is usually supplied to hospitals through a Mo/ Tc radionuclide generator system where it is produced from the ß decay of the parent nuclide Mo (t = 66 h), which is produced in nuclear reactors via neutron fission. Recently, the interruption of the global supply chain of reactor-produced Mo, has forced the scientific community to investigate alternative production routes for Tc. One solution was to consider cyclotron-based methods as potential replacement of reactor-based technology and the nuclear reaction Mo(p,2n) Tc emerged as the most worthwhile approach. This review reports some achievements about Tc produced by medical cyclotrons. In particular, the available technologies for target design, the most efficient extraction and separation procedure developed for the purification of Tc from the irradiated targets, the preparation of high purity Tc radiopharmaceuticals and the first clinical studies carried out with cyclotron produced Tc are described.
[Mh] Termos MeSH primário: Ciclotrons/instrumentação
Radioisótopos/química
Compostos Radiofarmacêuticos/química
Tecnécio/química
[Mh] Termos MeSH secundário: Meia-Vida
Seres Humanos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Radioisotopes); 0 (Radiopharmaceuticals); 7440-26-8 (Technetium)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170928
[Lr] Data última revisão:
170928
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170427
[St] Status:MEDLINE
[do] DOI:10.1080/03639045.2017.1323911


  3 / 1162 MEDLINE  
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[PMID]:28017863
[Au] Autor:Wang X; Han J; Hardie DB; Yang J; Pan J; Borchers CH
[Ad] Endereço:University of Victoria-Genome British Columbia Proteomics Centre, Vancouver Island Technology Park, #3101-4464 Markham St., Victoria, BC V8Z 7X8, Canada.
[Ti] Título:Metabolomic profiling of prostate cancer by matrix assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry imaging using Matrix Coating Assisted by an Electric Field (MCAEF).
[So] Source:Biochim Biophys Acta;1865(7):755-767, 2017 07.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:In this work, we combined the use of two MALDI matrices (quercetin and 9-aminoacridine), a recently developed new matrix coating technique - matrix coating assisted by an electric field (MCAEF), and matrix-assisted laser desorption/ionization - Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICRMS) to detect and image endogenous compounds in the cancerous and non-cancerous regions of three human prostate cancer (stage II) tissue specimens. After three rounds of imaging data acquisitions (i.e., quercetin for positive and negative ion detection and 9-aminoacridine for negative ion detection), and metabolite identification, a total of 1091 metabolites including 1032 lipids and 59 other metabolites were routinely detected and successfully localized. Of these compounds, 250 and 217 were only detected in either the cancerous or the non-cancerous regions respectively, although we cannot rule out the presence of these metabolites at concentrations below the detection limit. In addition, 152 of the other 624 metabolites showed differential distributions (p<0.05, t-test) between the two regions of the tissues. Further studies on a larger number of clinical specimens will need to be carried out to confirm this large number of apparently cancer-related metabolites. The successful determination of the spatial locations and abundances of these endogenous biomolecules indicated significant metabolism abnormalities - e.g., increased energy charge and under-expression of neutral acyl glycerides, in the prostate cancer samples. To our knowledge, this work has resulted in MALDI-MS imaging of the largest group of metabolites in prostate cancer thus far and demonstrated the importance of using complementary matrices for comprehensive metabolomic imaging by MALDI-MS. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.
[Mh] Termos MeSH primário: Metaboloma/fisiologia
Neoplasias da Próstata/metabolismo
[Mh] Termos MeSH secundário: Ciclotrons
Análise de Fourier
Seres Humanos
Limite de Detecção
Lipídeos/fisiologia
Masculino
Metabolômica/métodos
Meia-Idade
Quercetina/metabolismo
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
alfa-Glucosidases/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Lipids); 9IKM0I5T1E (Quercetin); EC 3.2.1.20 (alpha-Glucosidases)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161227
[St] Status:MEDLINE


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[PMID]:27936753
[Au] Autor:Anderson LC; DeHart CJ; Kaiser NK; Fellers RT; Smith DF; Greer JB; LeDuc RD; Blakney GT; Thomas PM; Kelleher NL; Hendrickson CL
[Ad] Endereço:Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory , Tallahassee, Florida 32310, United States.
[Ti] Título:Identification and Characterization of Human Proteoforms by Top-Down LC-21 Tesla FT-ICR Mass Spectrometry.
[So] Source:J Proteome Res;16(2):1087-1096, 2017 Feb 03.
[Is] ISSN:1535-3907
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Successful high-throughput characterization of intact proteins from complex biological samples by mass spectrometry requires instrumentation capable of high mass resolving power, mass accuracy, sensitivity, and spectral acquisition rate. These limitations often necessitate the performance of hundreds of LC-MS/MS experiments to obtain reasonable coverage of the targeted proteome, which is still typically limited to molecular weights below 30 kDa. The National High Magnetic Field Laboratory (NHMFL) recently installed a 21 T FT-ICR mass spectrometer, which is part of the NHMFL FT-ICR User Facility and available to all qualified users. Here we demonstrate top-down LC-21 T FT-ICR MS/MS of intact proteins derived from human colorectal cancer cell lysate. We identified a combined total of 684 unique protein entries observed as 3238 unique proteoforms at a 1% false discovery rate, based on rapid, data-dependent acquisition of collision-induced and electron-transfer dissociation tandem mass spectra from just 40 LC-MS/MS experiments. Our identifications included 372 proteoforms with molecular weights over 30 kDa detected at isotopic resolution, which substantially extends the accessible mass range for high-throughput top-down LC-MS/MS.
[Mh] Termos MeSH primário: Neoplasias Colorretais/química
Espectrometria de Massas/métodos
Proteínas de Neoplasias/análise
Proteoma/análise
Proteômica/métodos
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Neoplasias Colorretais/patologia
Misturas Complexas/química
Ciclotrons/instrumentação
Análise de Fourier
Seres Humanos
Espectrometria de Massas/instrumentação
Proteômica/instrumentação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Complex Mixtures); 0 (Neoplasm Proteins); 0 (Proteome)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171016
[Lr] Data última revisão:
171016
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161213
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jproteome.6b00696


  5 / 1162 MEDLINE  
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[PMID]:27932526
[Au] Autor:Reiding KR; Ruhaak LR; Uh HW; El Bouhaddani S; van den Akker EB; Plomp R; McDonnell LA; Houwing-Duistermaat JJ; Slagboom PE; Beekman M; Wuhrer M
[Ad] Endereço:From the ‡Center for Proteomics and Metabolomics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
[Ti] Título:Human Plasma N-glycosylation as Analyzed by Matrix-Assisted Laser Desorption/Ionization-Fourier Transform Ion Cyclotron Resonance-MS Associates with Markers of Inflammation and Metabolic Health.
[So] Source:Mol Cell Proteomics;16(2):228-242, 2017 Feb.
[Is] ISSN:1535-9484
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Glycosylation is an abundant co- and post-translational protein modification of importance to protein processing and activity. Although not template-defined, glycosylation does reflect the biological state of an organism and is a high-potential biomarker for disease and patient stratification. However, to interpret a complex but informative sample like the total plasma N-glycome, it is important to establish its baseline association with plasma protein levels and systemic processes. Thus far, large-scale studies (n >200) of the total plasma N-glycome have been performed with methods of chromatographic and electrophoretic separation, which, although being informative, are limited in resolving the structural complexity of plasma N-glycans. MS has the opportunity to contribute additional information on, among others, antennarity, sialylation, and the identity of high-mannose type species.Here, we have used matrix-assisted laser desorption/ionization (MALDI)-Fourier transform ion cyclotron resonance (FTICR)-MS to study the total plasma N-glycome of 2144 healthy middle-aged individuals from the Leiden Longevity Study, to allow association analysis with markers of metabolic health and inflammation. To achieve this, N-glycans were enzymatically released from their protein backbones, labeled at the reducing end with 2-aminobenzoic acid, and following purification analyzed by negative ion mode intermediate pressure MALDI-FTICR-MS. In doing so, we achieved the relative quantification of 61 glycan compositions, ranging from Hex HexNAc to Hex HexNAc dHex Neu5Ac , as well as that of 39 glycosylation traits derived thereof. Next to confirming known associations of glycosylation with age and sex by MALDI-FTICR-MS, we report novel associations with C-reactive protein (CRP), interleukin 6 (IL-6), body mass index (BMI), leptin, adiponectin, HDL cholesterol, triglycerides (TG), insulin, gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), and smoking. Overall, the bisection, galactosylation, and sialylation of diantennary species, the sialylation of tetraantennary species, and the size of high-mannose species proved to be important plasma characteristics associated with inflammation and metabolic health.
[Mh] Termos MeSH primário: Biomarcadores/sangue
Inflamação/metabolismo
Proteômica/instrumentação
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/instrumentação
[Mh] Termos MeSH secundário: Idoso
Índice de Massa Corporal
Proteína C-Reativa/metabolismo
Ciclotrons
Análise de Fourier
Glicosilação
Seres Humanos
Masculino
Meia-Idade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 9007-41-4 (C-Reactive Protein)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170620
[Lr] Data última revisão:
170620
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161210
[St] Status:MEDLINE
[do] DOI:10.1074/mcp.M116.065250


  6 / 1162 MEDLINE  
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[PMID]:27755293
[Au] Autor:Kumar R; Sonkawade RG; Pandey AK; Tripathi M; Damle NA; Kumar P; Bal CS
[Ad] Endereço:aDepartment of Nuclear Medicine and PET Cyclotron Facility, All India Institute of Medical Sciences, New Delhi bDepartment of Physics, Shivaji University, Kolhapur, Maharashtra, India.
[Ti] Título:Practical experience and challenges in the operation of medical cyclotron.
[So] Source:Nucl Med Commun;38(1):10-14, 2017 Jan.
[Is] ISSN:1473-5628
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:OBJECTIVE: The aim of this article was to share 10 years of operational experience of medical cyclotron and to provide working knowledge on the same. This experience has helped us gain working knowledge on cyclotron operation with practical points, which may help in improving F yield, minimizing the breakdown time, and help in the prevention of the occurrence of unusual events. MATERIALS AND METHODS: Our facility has a self-shielded radioisotope delivery system eclipse 111 medical cyclotron with an 11 MeV proton beam in use for the past 10 years to produce positron emitters - namely, F, N, and F-2 gas - for PET imaging. During F production, we have followed a set protocol comprising the following: monitoring target pressure, rinsing the target with O water just immediately after bombardment, ion source feedback, radiofrequency (RF) feedback, and recording any unusual events that occurred during the operation. Besides this, enrichment of O water, target volume, target current, energy of the beam, variation in argon pressure on the target, bombardment duration, target status (new or old target or total number of previous bombardments on the same target), status of the delivery lines from target to the radiochemistry module (old or new) were also recorded. RESULTS: Rinsing with O water immediately after bombardment increases the life of the target and delivery line. The frequent problems encountered were with the ion source, RF, and target foil rupture. These problems were solved by rebuilding the ion source, changing the fuse of RF, and rebuilding the target. CONCLUSION: F yield can be increased by rinsing with O water immediately after bombardment. The effect of target leak - that is, rupture of vacuum window - can be avoided by immediate stoppage of bombardment.
[Mh] Termos MeSH primário: Ciclotrons
[Mh] Termos MeSH secundário: Radioisótopos de Flúor/isolamento & purificação
Seres Humanos
Índia
Manutenção/métodos
Radioisótopos de Nitrogênio/isolamento & purificação
Medicina Nuclear/instrumentação
Medicina Nuclear/métodos
Oxigênio
Tomografia por Emissão de Pósitrons/métodos
Compostos Radiofarmacêuticos/isolamento & purificação
Água
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fluorine Radioisotopes); 0 (Nitrogen Radioisotopes); 0 (Radiopharmaceuticals); 059QF0KO0R (Water); S88TT14065 (Oxygen)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170817
[Lr] Data última revisão:
170817
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161019
[St] Status:MEDLINE


  7 / 1162 MEDLINE  
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[PMID]:27744544
[Au] Autor:Ishiwata K; Hayashi K; Sakai M; Kawauchi S; Hasegawa H; Toyohara J
[Ad] Endereço:Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. kiichiishiwata@gmail.com.
[Ti] Título:Determination of radionuclides and radiochemical impurities produced by in-house cyclotron irradiation and subsequent radiosynthesis of PET tracers.
[So] Source:Ann Nucl Med;31(1):84-92, 2017 Jan.
[Is] ISSN:1864-6433
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:OBJECTIVE: To elucidate the radionuclides and radiochemical impurities included in radiosynthesis processes of positron emission tomography (PET) tracers. METHODS: Target materials and PET tracers were produced using a cyclotron/synthesis system from Sumitomo Heavy Industry. Positron and γ-ray emitting radionuclides were quantified by measuring radioactivity decay and using the high-purity Ge detector, respectively. Radiochemical species in gaseous and aqueous target materials were analyzed by gas and ion chromatography, respectively. RESULTS: Target materials had considerable levels of several positron emitters in addition to the positron of interest, and in the case of aqueous target materials extremely low levels of many γ-emitters. Five C-, O-, or F-labeled tracers produced from gaseous materials via chemical reactions had no radionuclidic impurities, whereas F-FDG, F-NaF, and N-NH produced from aqueous materials had several γ-emitters as well as impure positron emitters. O-Labeled CO , O , and CO had a radionuclidic impurity N-N (0.5-0.7 %). CONCLUSIONS: Target materials had several positron emitters other than the positron of interest, and extremely low level γ-emitters in the case of aqueous materials. PET tracers produced from gaseous materials except for O-labeled gases had no impure radionuclides, whereas those derived from aqueous materials contained acceptable levels of impure positron emitters and extremely low levels of several γ-emitters.
[Mh] Termos MeSH primário: Ciclotrons
Tomografia por Emissão de Pósitrons
Radioquímica/instrumentação
Radioisótopos/química
Compostos Radiofarmacêuticos/química
[Mh] Termos MeSH secundário: Raios gama
Meia-Vida
Controle de Qualidade
Traçadores Radioativos
Compostos Radiofarmacêuticos/síntese química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Radioactive Tracers); 0 (Radioisotopes); 0 (Radiopharmaceuticals)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170224
[Lr] Data última revisão:
170224
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161017
[St] Status:MEDLINE
[do] DOI:10.1007/s12149-016-1134-3


  8 / 1162 MEDLINE  
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[PMID]:27738005
[Au] Autor:Selivanova SV; Lavallée É; Senta H; Caouette L; McEwan AJB; Guérin B; Lecomte R; Turcotte É
[Ad] Endereço:Sherbrooke Molecular Imaging Center, CRCHUS, Sherbrooke, Quebec, Canada Svetlana.V.Selivanova@USherbrooke.ca.
[Ti] Título:Clinical Trial with Sodium Tc-Pertechnetate Produced by a Medium-Energy Cyclotron: Biodistribution and Safety Assessment in Patients with Abnormal Thyroid Function.
[So] Source:J Nucl Med;58(5):791-798, 2017 May.
[Is] ISSN:1535-5667
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A single-site prospective open-label clinical study with cyclotron-produced sodium Tc-pertechnetate ( Tc-NaTcO ) was performed in patients with indications for a thyroid scan to demonstrate the clinical safety and diagnostic efficacy of the drug and to confirm its equivalence with conventional Tc-NaTcO eluted from a generator. Tc-NaTcO was produced from enriched Mo (99.815%) with a cyclotron (24 MeV; 2 h of irradiation) or supplied by a commercial manufacturer (bulk vial eluted from a generator). Eleven patients received 325 ± 29 (mean ± SD) MBq of the cyclotron-produced Tc-NaTcO , whereas the age- and sex-matched controls received a comparable amount of the generator-derived tracer. Whole-body and thyroid planar images were obtained for each participant. In addition to the standard-energy window (140.5 keV ± 7.5%), data were acquired in lower-energy (117 keV ± 10%) and higher-energy (170 keV ± 10%) windows. Vital signs and hematologic and biochemical parameters were monitored before and after tracer administration. Cyclotron-produced Tc-NaTcO showed organ and whole-body distributions identical to those of conventional Tc-NaTcO and was well tolerated. All images led to a clear final diagnosis. The fact that the number of counts in the higher-energy window was significantly higher for cyclotron-produced Tc-NaTcO did not influence image quality in the standard-energy window. Image definition in the standard-energy window with cyclotron-produced Tc was equivalent to that with generator-eluted Tc and had no particular features allowing discrimination between the Tc production methods. The systemic distribution, clinical safety, and imaging efficacy of cyclotron-produced Tc-NaTcO in humans provide supporting evidence for the use of this tracer as an equivalent for generator-eluted Tc-NaTcO in routine clinical practice.
[Mh] Termos MeSH primário: Ciclotrons/instrumentação
Lesões por Radiação/etiologia
Pertecnetato Tc 99m de Sódio/efeitos adversos
Pertecnetato Tc 99m de Sódio/farmacocinética
Doenças da Glândula Tireoide/diagnóstico por imagem
Doenças da Glândula Tireoide/metabolismo
[Mh] Termos MeSH secundário: Adulto
Idoso
Idoso de 80 Anos ou mais
Desenho de Equipamento
Feminino
Seres Humanos
Marcação por Isótopo/instrumentação
Masculino
Taxa de Depuração Metabólica
Meia-Idade
Especificidade de Órgãos
Lesões por Radiação/diagnóstico
Lesões por Radiação/prevenção & controle
Geradores de Radionuclídeos
Compostos Radiofarmacêuticos/efeitos adversos
Compostos Radiofarmacêuticos/síntese química
Compostos Radiofarmacêuticos/farmacocinética
Reprodutibilidade dos Testes
Sensibilidade e Especificidade
Pertecnetato Tc 99m de Sódio/síntese química
Distribuição Tecidual
[Pt] Tipo de publicação:CLINICAL TRIAL; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Radiopharmaceuticals); A0730CX801 (Sodium Pertechnetate Tc 99m)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170606
[Lr] Data última revisão:
170606
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161015
[St] Status:MEDLINE
[do] DOI:10.2967/jnumed.116.178509


  9 / 1162 MEDLINE  
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[PMID]:27368079
[Au] Autor:D'Emilia E; Ledda M; Foletti A; Lisi A; Giuliani L; Grimaldi S; Liboff AR
[Ad] Endereço:a Department of Anthropic Settlements , INAIL (National Institute for Insurance against Accidents at Work) , Rome , Italy.
[Ti] Título:Weak-field H O ion cyclotron resonance alters water refractive index.
[So] Source:Electromagn Biol Med;36(1):55-62, 2017.
[Is] ISSN:1536-8386
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Heretofore only observed in living systems, we report that weak-field ion cyclotron resonance (ICR) also occurs in inanimate matter. Weak magnetic field (50 nT) hydronium ICR at the field combination (7.84 Hz, 7.5 µT) markedly changes water structure, as evidenced by finding an altered index of refraction exactly at this combined field. This observation utilizes a novel technique which measures the scattering of a He-Ne laser beam as the sample is exposed to a ramped magnetic field frequency. In addition to the hydronium resonance, we find evidence of ICR coupling to a more massive structure, possibly a tetrahedral combination of three waters and a single hydronium ion. To check our observations, we extended this technique to D O, successfully predicting the specific ICR charge-to-mass ratio for D O that alters the index of refraction.
[Mh] Termos MeSH primário: Ciclotrons
Oniocompostos/química
Refratometria/instrumentação
Água/química
[Mh] Termos MeSH secundário: Óxido de Deutério/química
Campos Magnéticos
Vibração
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Onium Compounds); 059QF0KO0R (Water); 5046UKT60S (hydronium ion); J65BV539M3 (Deuterium Oxide)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170210
[Lr] Data última revisão:
170210
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160702
[St] Status:MEDLINE


  10 / 1162 MEDLINE  
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[PMID]:27993037
[Au] Autor:Feng L; Xu J; Kang S; Li X; Li Y; Jiang B; Shi Q
[Ad] Endereço:State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences , Lanzhou 730000, China.
[Ti] Título:Chemical Composition of Microbe-Derived Dissolved Organic Matter in Cryoconite in Tibetan Plateau Glaciers: Insights from Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Analysis.
[So] Source:Environ Sci Technol;50(24):13215-13223, 2016 Dec 20.
[Is] ISSN:1520-5851
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cryoconite in mountain glaciers plays important roles in glacial ablation and biogeochemical cycles. In this study, the composition and sources of dissolved organic matter (DOM) in cryoconite from the ablation regions of two Tibetan Plateau glaciers were determined using electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and fluorescence spectrometry. A marked absorbance between 300 and 350 nm in the DOM absorption spectra was observed which was consistent with microbe-derived mycosporine-like amino acids. Fluorescence excitation-emission matrices showed that DOM had intense signals at protein-like substance peaks and weak signals at humic-like substance peaks. The high-resolution mass spectra of FT-ICR-MS showed cryoconite DOM from both glaciers contained diverse lignins, lipids, proteins, and unsaturated hydrocarbons. The lipids and proteins were consistent with material from microbial sources, and the lignins and unsaturated hydrocarbons were probably from vascular plant material supplied in atmospheric aerosols and debris from around the glaciers. Almost one-third of the identified DOM molecules had low C/N ratios (≤20), indicating their high bioavailability. Using a conservative cryoconite distribution on Chinese mountain glacier surfaces (6%) and an average debris mass per square meter of cryoconite (292 ± 196 g m ), we found that the amount of DOC produced in cryoconite on Chinese glaciers as much as 0.23 ± 0.1 Gg per cryoconite formation process. This dissolved organic carbon may absorb solar radiation, accelerate glacial melting, and be an important source of bioavailable DOM to proglacial and downstream aquatic ecosystems.
[Mh] Termos MeSH primário: Análise de Fourier
Camada de Gelo/química
[Mh] Termos MeSH secundário: Ciclotrons
Espectrometria de Massas
Tibet
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170608
[Lr] Data última revisão:
170608
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161221
[St] Status:MEDLINE



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