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[PMID]:29304182
[Au] Autor:Gonçalves-Araujo R; Rabe B; Peeken I; Bracher A
[Ad] Endereço:Phytooptics Group, Physical Oceanography of Polar Seas, Climate Sciences Division, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.
[Ti] Título:High colored dissolved organic matter (CDOM) absorption in surface waters of the central-eastern Arctic Ocean: Implications for biogeochemistry and ocean color algorithms.
[So] Source:PLoS One;13(1):e0190838, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:As consequences of global warming sea-ice shrinking, permafrost thawing and changes in fresh water and terrestrial material export have already been reported in the Arctic environment. These processes impact light penetration and primary production. To reach a better understanding of the current status and to provide accurate forecasts Arctic biogeochemical and physical parameters need to be extensively monitored. In this sense, bio-optical properties are useful to be measured due to the applicability of optical instrumentation to autonomous platforms, including satellites. This study characterizes the non-water absorbers and their coupling to hydrographic conditions in the poorly sampled surface waters of the central and eastern Arctic Ocean. Over the entire sampled area colored dissolved organic matter (CDOM) dominates the light absorption in surface waters. The distribution of CDOM, phytoplankton and non-algal particles absorption reproduces the hydrographic variability in this region of the Arctic Ocean which suggests a subdivision into five major bio-optical provinces: Laptev Sea Shelf, Laptev Sea, Central Arctic/Transpolar Drift, Beaufort Gyre and Eurasian/Nansen Basin. Evaluating ocean color algorithms commonly applied in the Arctic Ocean shows that global and regionally tuned empirical algorithms provide poor chlorophyll-a (Chl-a) estimates. The semi-analytical algorithms Generalized Inherent Optical Property model (GIOP) and Garver-Siegel-Maritorena (GSM), on the other hand, provide robust estimates of Chl-a and absorption of colored matter. Applying GSM with modifications proposed for the western Arctic Ocean produced reliable information on the absorption by colored matter, and specifically by CDOM. These findings highlight that only semi-analytical ocean color algorithms are able to identify with low uncertainty the distribution of the different optical water constituents in these high CDOM absorbing waters. In addition, a clustering of the Arctic Ocean into bio-optical provinces will help to develop and then select province-specific ocean color algorithms.
[Mh] Termos MeSH primário: Algoritmos
Cor
[Mh] Termos MeSH secundário: Regiões Árticas
Clorofila/análise
Oceanos e Mares
Compostos Orgânicos/química
Fenômenos Físicos
Solubilidade
Análise Espectral/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Organic Chemicals); 1406-65-1 (Chlorophyll); YF5Q9EJC8Y (chlorophyll a)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180106
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190838


  2 / 3977 MEDLINE  
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[PMID]:29195356
[Au] Autor:Wang J; Liu F; Mo Y; Wang Z; Zhang S; Zhang X
[Ad] Endereço:State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
[Ti] Título:A new instrument of VUV laser desorption/ionization mass spectrometry imaging with micrometer spatial resolution and low level of molecular fragmentation.
[So] Source:Rev Sci Instrum;88(11):114102, 2017 Nov.
[Is] ISSN:1089-7623
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mass spectrometry imaging (MSI) has important applications in material research, biology, and medicine. The MSI method based on UV laser desorption/ionization (UVLDI) can obtain images of intact samples, but has a high level of molecular fragmentation. In this work, we report a new MSI instrument that uses a VUV laser (125.3 nm) as a desorption/ionization source to exploit its advantages of high single photon energy and small focus size. The new instrument was tested by the mass spectra of Nile red and FGB (Fibrinogen beta chain) samples and mass spectrometric images of a fly brain section. For the tested samples, the VUVDI method offers lower levels of molecular fragmentations and higher sensitivities than those of the UVLDI method and second ion mass spectrometry imaging method using a Bi beam. The ablation crater produced by the focused VUV laser on a quartz plate has an area of 10 µm . The VUV laser is prepared based on the four-wave mixing method using three collimated laser beams and a heated Hg cell.
[Mh] Termos MeSH primário: Lasers
Espectrometria de Massas/instrumentação
Fótons
[Mh] Termos MeSH secundário: Peso Molecular
Fenômenos Físicos
Espectrofotometria
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180209
[Lr] Data última revisão:
180209
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171203
[St] Status:MEDLINE
[do] DOI:10.1063/1.4994173


  3 / 3977 MEDLINE  
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[PMID]:29323659
[Au] Autor:Zwar E; Kemna A; Richter L; Degen P; Rehage H
[Ad] Endereço:Physikalische Chemie II, TU Dortmund, 44227 Dortmund, Germany.
[Ti] Título:Production, deformation and mechanical investigation of magnetic alginate capsules.
[So] Source:J Phys Condens Matter;30(8):085101, 2018 Feb 28.
[Is] ISSN:1361-648X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In this article we investigated the deformation of alginate capsules in magnetic fields. The sensitivity to magnetic forces was realised by encapsulating an oil in water emulsion, where the oil droplets contained dispersed magnetic nanoparticles. We solved calcium ions in the aqueous emulsion phase, which act as crosslinking compounds for forming thin layers of alginate membranes. This encapsulating technique allows the production of flexible capsules with an emulsion as the capsule core. It is important to mention that the magnetic nanoparticles were stable and dispersed throughout the complete process, which is an important difference to most magnetic alginate-based materials. In a series of experiments, we used spinning drop techniques, capsule squeezing experiments and interfacial shear rheology in order to determine the surface Young moduli, the surface Poisson ratios and the surface shear moduli of the magnetically sensitive alginate capsules. In additional experiments, we analysed the capsule deformation in magnetic fields. In spinning drop and capsule squeezing experiments, water droplets were pressed out of the capsules at elevated values of the mechanical load. This phenomenon might be used for the mechanically triggered release of water-soluble ingredients. After drying the emulsion-filled capsules, we produced capsules, which only contained a homogeneous oil phase with stable suspended magnetic nanoparticles (organic ferrofluid). In the dried state, the thin alginate membranes of these particles were rather rigid. These dehydrated capsules could be stored at ambient conditions for several months without changing their properties. After exposure to water, the alginate membranes rehydrated and became flexible and deformable again. During this swelling process, water diffused back in the capsule. This long-term stability and rehydration offers a great spectrum of different applications as sensors, soft actuators, artificial muscles or drug delivery systems.
[Mh] Termos MeSH primário: Alginatos
Cápsulas
Campos Magnéticos
[Mh] Termos MeSH secundário: Difusão
Módulo de Elasticidade
Emulsões
Ácido Glucurônico
Ácidos Hexurônicos
Membranas Artificiais
Fenômenos Físicos
Reologia
Água
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Alginates); 0 (Capsules); 0 (Emulsions); 0 (Hexuronic Acids); 0 (Membranes, Artificial); 059QF0KO0R (Water); 8A5D83Q4RW (Glucuronic Acid); 8C3Z4148WZ (alginic acid)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180208
[Lr] Data última revisão:
180208
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180112
[St] Status:MEDLINE
[do] DOI:10.1088/1361-648X/aaa6f5


  4 / 3977 MEDLINE  
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[PMID]:29269461
[Au] Autor:Dalton CA
[Ad] Endereço:Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA. colleen_dalton@brown.edu.
[Ti] Título:How seismic waves lose energy.
[So] Source:Science;358(6370):1536-1537, 2017 12 22.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Mh] Termos MeSH primário: Fenômenos Eletromagnéticos
Fenômenos Físicos
[Mh] Termos MeSH secundário: Acústica
Ondas de Rádio
Ondas de Maré
Vibração
[Pt] Tipo de publicação:JOURNAL ARTICLE; COMMENT
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171227
[Lr] Data última revisão:
171227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171223
[St] Status:MEDLINE
[do] DOI:10.1126/science.aar2748


  5 / 3977 MEDLINE  
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[PMID]:28467324
[Au] Autor:Them K
[Ad] Endereço:Section for Biomedical Imaging, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg. Institute for Biomedical Imaging, Hamburg University of Technology, Schwarzenbergstrasse 95, 21073 Hamburg, Germany.
[Ti] Título:On magnetic dipole-dipole interactions of nanoparticles in magnetic particle imaging.
[So] Source:Phys Med Biol;62(14):5623-5639, 2017 Jun 14.
[Is] ISSN:1361-6560
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Magnetic dipole-dipole (MDD) interactions between iron oxide nanoparticles can influence the sensitivity, image resolution and quantification of magnetic particle imaging (MPI). For the first time, the Landau-Lifshitz-Gilbert equation (LLG) for MDD interactions has been solved to investigate the effect of MDD interactions on the MPI spectrum. It was found that at concentrations above 39 mmol(Fe) l , MDD interactions significantly influence MPI spectra. This influence increases with increasing harmonics, which means first harmonics should be preferred for iron quantification. Since ≈10 particles are neglected in the LLG compared to in an MPI experiment, the calculated limit below which MDD interactions can be neglected is only a bound. The true limit is therefore below the calculated limit of 39 mmol(Fe) l , because all other neglected particles also contribute to deviations in the MPI spectra via MDD interactions. Therefore, a quantum mechanical bound on the influence of MDD interactions is calculated, including up to 10 particles. Analysis of the bound as a function of the particle number provides a valuable insight into the influence of the large number of particles neglected in numerical simulations. Both results are compared with concentrations in biomedical MPI experiments. We conclude that the standard approximation of an absence of MDD interactions in MPI experiments must be handled more carefully. Our method of incorporating MDD interactions into the LLG can be easily implemented as part of model-based reconstruction to increase the sensitivity, image resolution and quantitative tracer detection during MPI.
[Mh] Termos MeSH primário: Compostos Férricos/química
Imãs/química
Nanopartículas
Fenômenos Físicos
Tomografia/métodos
[Mh] Termos MeSH secundário: Processamento de Imagem Assistida por Computador
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ferric Compounds); 1K09F3G675 (ferric oxide)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171211
[Lr] Data última revisão:
171211
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170504
[St] Status:MEDLINE
[do] DOI:10.1088/1361-6560/aa70ca


  6 / 3977 MEDLINE  
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[PMID]:28981539
[Au] Autor:Islam S; Nazeer G; Ying ZC; Islam Z; Manzoor R
[Ad] Endereço:COMSATS Institute of Information Technology Islamabad, Mathematics Department, Islamabad, Pakistan.
[Ti] Título:Transitions in the flow patterns and aerodynamic characteristics of the flow around staggered rows of cylinders.
[So] Source:PLoS One;12(10):e0184169, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A two-dimensional numerical study of flow across rows of identical square cylinders arranged in staggered fashion is carried out. This study will unreveal complex flow physics depending upon the Reynolds number (Re) and gap spacing (g) between the cylinders. The combined effect of Reynolds number and gap spacing on the flow physics around staggered rows of cylinders are numerically studied for 20 ≤ Re ≤ 140 and 1 ≤ g ≤ 6. We use the lattice Boltzmann method for numerical computations. It is found that with increase in gap spacing between the cylinders the critical Reynolds number for the onset of vortex shedding also increases. We observed a strong effect of Reynolds number at g = 2 and 4. Secondary cylinder interaction frequency disappears for large Reynolds number at g = 6 and 5 and the flow around cylinders are fully dominated by the primary vortex shedding frequency. This ensures that at large gap spacing with an increase in the Reynolds number the wakes interaction between and behind the cylinders is weaken. Furthermore, it also ensures that the wake interaction behind the cylinders is strongly influenced by the jets in the gap spacing between the cylinders. We also found that g = 2 is the critical gap spacing for flow across rows of staggered square cylinders for the considered range of Reynolds number. Depending on the Reynolds number we observed; synchronous, quasi-periodic-I, quasi-periodic-II, and chaotic flow patterns. In synchronous flow pattern, an in-phase and anti-phase characteristics of consecutive cylinders has been observed. The important physical parameters are also analyzed and discussed in detail.
[Mh] Termos MeSH primário: Modelos Teóricos
Fenômenos Físicos
[Mh] Termos MeSH secundário: Simulação por Computador
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171022
[Lr] Data última revisão:
171022
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171006
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184169


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[PMID]:28957386
[Au] Autor:Stabeno PJ; Duffy-Anderson JT; Eisner LB; Farley EV; Heintz RA; Mordy CW
[Ad] Endereço:NOAA Pacific Marine Environmental Laboratory, Seattle, Washington, United States of America.
[Ti] Título:Return of warm conditions in the southeastern Bering Sea: Physics to fluorescence.
[So] Source:PLoS One;12(9):e0185464, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:From 2007 to 2013, the southeastern Bering Sea was dominated by extensive sea ice and below-average ocean temperatures. In 2014 there was a shift to reduced sea ice on the southern shelf and above-average ocean temperatures. These conditions continued in 2015 and 2016. During these three years, the spring bloom at mooring site M4 (57.9°N, 168.9°W) occurred primarily in May, which is typical of years without sea ice. At mooring site M2 (56.9°N, 164.1°W) the spring bloom occurred earlier especially in 2016. Higher chlorophyll fluorescence was observed at M4 than at M2. In addition, these three warm years continued the pattern near St. Matthew Island of high concentrations (>1 µM) of nitrite occurring during summer in warm years. Historically, the dominant parameters controlling sea-ice extent are winds and air temperature, with the persistence of frigid, northerly winds in winter and spring resulting in extensive ice. After mid-March 2014 and 2016 there were no cold northerly or northeasterly winds. Cold northerly winds persisted into mid-April in 2015, but did not result in extensive sea ice south of 58°N. The apparent mechanism that helped limit ice on the southeastern shelf was the strong advection of warm water from the Gulf of Alaska through Unimak Pass. This pattern has been uncommon, occurring in only one other year (2003) in a 37-year record of estimated transport through Unimak Pass. During years with no sea ice on the southern shelf (e.g. 2001-2005, 2014-2016), the depth-averaged temperature there was correlated to the previous summers ocean temperature.
[Mh] Termos MeSH primário: Temperatura Alta
Oceanos e Mares
Fenômenos Físicos
[Mh] Termos MeSH secundário: Fenômenos Biofísicos
Clorofila/análise
Fluorescência
Geografia
Camada de Gelo
Nitritos/análise
Vento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Nitrites); 1406-65-1 (Chlorophyll)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170929
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0185464


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[PMID]:28774917
[Au] Autor:Hardie DG
[Ad] Endereço:Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK. d.g.hardie@dundee.ac.uk.
[Ti] Título:Targeting an energy sensor to treat diabetes.
[So] Source:Science;357(6350):455-456, 2017 08 04.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Mh] Termos MeSH primário: Glicemia
Diabetes Mellitus
[Mh] Termos MeSH secundário: Seres Humanos
Fenômenos Físicos
[Pt] Tipo de publicação:JOURNAL ARTICLE; COMMENT
[Nm] Nome de substância:
0 (Blood Glucose)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171023
[Lr] Data última revisão:
171023
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170805
[St] Status:MEDLINE
[do] DOI:10.1126/science.aao1913


  9 / 3977 MEDLINE  
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[PMID]:28750072
[Au] Autor:Beczek M; Ryzak M; Sochan A; Mazur R; Polakowski C; Bieganowski A
[Ad] Endereço:Institute of Agrophysics PAS, Lublin, Poland.
[Ti] Título:The differences in crown formation during the splash on the thin water layers formed on the saturated soil surface and model surface.
[So] Source:PLoS One;12(7):e0181974, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Splash is the first stage of a negative phenomenon-soil erosion. The aim of this work was to describe the crown formation quantitatively (as part of the splash erosion) and compare the course of this phenomenon on the thin water film formed on a smooth glass surface and on the surface of saturated soil. The height of the falling water drop was 1.5 m. The observation of the crowns was carried out by high-speed cameras. The static and dynamic parameters of crown formation were analysed. It was found that the crowns formed on the water film covering the saturated soil surface were smaller and the time intervals of their existence were shorter. In addition, the shapes of the crowns were different from those created on the water layer covering the glass surface. These differences can be explained by the slightly different values of surface tension and viscosity of the soil solution, the greater roughness of the soil surface and the lower thickness of the water film on the soil surface.
[Mh] Termos MeSH primário: Modelos Teóricos
Fenômenos Físicos
Solo/química
Água/química
[Mh] Termos MeSH secundário: Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Soil); 059QF0KO0R (Water)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170728
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0181974


  10 / 3977 MEDLINE  
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[PMID]:28696688
[Au] Autor:Coley CW; Barzilay R; Green WH; Jaakkola TS; Jensen KF
[Ad] Endereço:Department of Chemical Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
[Ti] Título:Convolutional Embedding of Attributed Molecular Graphs for Physical Property Prediction.
[So] Source:J Chem Inf Model;57(8):1757-1772, 2017 Aug 28.
[Is] ISSN:1549-960X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The task of learning an expressive molecular representation is central to developing quantitative structure-activity and property relationships. Traditional approaches rely on group additivity rules, empirical measurements or parameters, or generation of thousands of descriptors. In this paper, we employ a convolutional neural network for this embedding task by treating molecules as undirected graphs with attributed nodes and edges. Simple atom and bond attributes are used to construct atom-specific feature vectors that take into account the local chemical environment using different neighborhood radii. By working directly with the full molecular graph, there is a greater opportunity for models to identify important features relevant to a prediction task. Unlike other graph-based approaches, our atom featurization preserves molecule-level spatial information that significantly enhances model performance. Our models learn to identify important features of atom clusters for the prediction of aqueous solubility, octanol solubility, melting point, and toxicity. Extensions and limitations of this strategy are discussed.
[Mh] Termos MeSH primário: Gráficos por Computador
Informática/métodos
Redes Neurais (Computação)
Fenômenos Físicos
[Mh] Termos MeSH secundário: Octanóis/química
Solubilidade
Testes de Toxicidade
Temperatura de Transição
Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Octanols); 059QF0KO0R (Water)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171002
[Lr] Data última revisão:
171002
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170712
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jcim.6b00601



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