scholarly journals EXPRESS: Visualization of Inter- and Intramolecular Interactions in Poly(3-hydroxybutyrate)/Poly(L-lactic acid) (PHB/PLLA) Blends During Isothermal Melt Crystallization Using Attenuated Reflection Fourier Transform infrared (ATR FT-IR) Spectroscopic Imaging

2021 ◽  
pp. 000370282110102
Author(s):  
Huiqiang Lu ◽  
Harumi Sato ◽  
Sergei G Kazarian
Keyword(s):  
Spatial Distribution ◽  
Intermolecular Interactions ◽  
Spectral Band ◽  
Spectroscopic Imaging ◽  
Peak Position ◽  
Intramolecular Interactions ◽  
Melt Crystallization ◽  
Polymer Systems ◽  
Multicomponent Polymer

Inter- and intramolecular interactions in multicomponent polymer systems influence their physical and chemical properties significantly and thus have implications on their synthesis and processing. In the present study, chemical images were obtained by plotting the peak position of a spectral band from the datasets generated by in-situ ATR-FTIR spectroscopic imaging. This approach was successfully used to visualize changes in intra- and intermolecular interactions in Poly(3-hydroxybutyrate)/Poly(L-lactic acid) (PHB/PLLA) blends during the isothermal melt crystallization. The peak position of ν (C=O) band, which reflects the nature of the intermolecular interaction, shows that the intermolecular interactions between PHB and PLLA in the miscible state (1733 cm-1) changes to the inter- and intramolecular interaction (CH3∙∙∙O=C, 1720 cm-1) within PHB crystal during the isothermal melt crystallization. Compared with spectroscopic images obtained by plotting the distribution of absorbance of spectral bands, which reveals the spatial distribution of blend components, the approach of plotting the peak position of a spectral band reflects the spatial distribution of different intra- and intermolecular interactions. With the process of isothermal melt-crystallization, the disappearance of the intermolecular interaction between PHB and PLLA and the appearance of the inter- and intramolecular interactions within the PHB crystal were both visualized through the images based on the observation of the band position. This work shows the potential of using in-situ ATR-FTIR spectroscopic imaging to visualize different types of inter- or intramolecular interactions between polymer molecules or between polymer and other additives in various types of multicomponent polymer systems.  

Ultrastructural analysis of the spatial distribution of MRNA

1992 ◽  
Vol 50 (1) ◽  
pp. 552-553
Author(s):  
Gary Bassell ◽  
Robert H. Singer
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Nucleic Acids ◽  
Colloidal Gold ◽  
Dna Probe ◽  
Nucleotide Analogs ◽  
Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

Spatial distribution of electrons ejected by two-photon excitation of aromatic molecules in polymer systems

2001 ◽  
Vol 60 (4-5) ◽  
pp. 427-432 ◽  
Author(s):  
Hideo Ohkita ◽  
Hironori Ishii ◽  
Takeo Ogi ◽  
Shinzaburo Ito ◽  
Masahide Yamamoto
Keyword(s):  
Spatial Distribution ◽  
Polymer Systems ◽  
Aromatic Molecules ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Digital autoradiography on C-14-labelled PMMA impregnated rock samples using the BeaverTM

MRS Advances ◽  
2018 ◽  
Vol 3 (21) ◽  
pp. 1161-1166 ◽  
Author(s):  
Mikko Voutilainen ◽  
Juuso Sammaljärvi ◽  
Eveliina Muuri ◽  
Jérôme Donnard ◽  
Samuel Duval ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spent Nuclear Fuel ◽  
Rock Sample ◽  
Crystalline Rock ◽  
Imaging Plate ◽  
Heterogeneous Distribution ◽  
Heterogeneous Structures ◽  
In Situ Diffusion

In Finland and Sweden the KBS-3 concept has been chosen for the disposal of spent nuclear fuel in crystalline rock. Recent experiments have shown that heterogeneity of rock may play a major role in the transport of radionuclides. Autoradiographic methods have been proven to be able to assist the characterization of heterogeneous structures. In this study we tested a novel filmless autoradiographic device called BeaverTM which applies a micro patterned gaseous detector in order to quantitatively map beta emissions from C-14 atoms. The studied samples were impregnated with C-14-labelled methylmethacrylate (C-14-MMA) and polymerized to C-14-PMMA with thermal initiator. The BeaverTM was then used to determine the spatial distribution of the C-14-PMMA by measuring the C-14 emissions. The porosity is determined from the amount of C-14-PMMA in the rock sample and results were compared to ones from phosphor imaging plate autoradiography. The resulting images show a heterogeneous distribution of porosity which arises from the different minerals. The samples were chosen from three sites that have been used recently for in situ diffusion experiments: Olkiluoto (Finland), Äspö (Sweden) and Grimsel (Switzerland).

scholarly journals A new pan-European dataset for gridded daily average wind speed based on in-situ observations

2021 ◽  
Author(s):  
Jouke de Baar ◽  
Gerard van der Schrier ◽  
Irene Garcia-Marti ◽  
Else van den Besselaar
Keyword(s):  
Spatial Distribution ◽  
High Resolution ◽  
Cross Validation ◽  
Data Sets ◽  
Optimal Prediction ◽  
Auxiliary Variables ◽  
Climate Data ◽  
Ensemble Spread ◽  
Wind Fields

<p><strong>Objective</strong></p><p>The purpose of the European Copernicus Climate Change Service (C3S) is to support society by providing information about the past, present and future climate. For the service related to <em>in-situ</em> observations, one of the objectives is to provide high-resolution (0.1x0.1 and 0.25x0.25 degrees) gridded wind speed fields. The gridded wind fields are based on ECA&D daily average station observations for the period 1970-2020.</p><p><strong>Research question</strong> </p><p>We address the following research questions: [1] How efficiently can we provide the gridded wind fields as a statistically reliable ensemble, in order to represent the uncertainty of the gridding? [2] How efficiently can we exploit high-resolution geographical auxiliary variables (e.g. digital elevation model, terrain roughness) to augment the station data from a sparse network, in order to provide gridded wind fields with high-resolution local features?</p><p><strong>Approach</strong></p><p>In our analysis, we apply greedy forward selection linear regression (FSLR) to include the high-resolution effects of the auxiliary variables on monthly-mean data. These data provide a ‘background’ for the daily estimates. We apply cross-validation to avoid FSLR over-fitting and use full-cycle bootstrapping to create FSLR ensemble members. Then, we apply Gaussian process regression (GPR) to regress the daily anomalies. We consider the effect of the spatial distribution of station locations on the GPR gridding uncertainty.</p><p>The goal of this work is to produce several decades of daily gridded wind fields, hence, computational efficiency is of utmost importance. We alleviate the computational cost of the FSLR and GPR analyses by incorporating greedy algorithms and sparse matrix algebra in the analyses.</p><p><strong>Novelty</strong>   </p><p>The gridded wind fields are calculated as a statistical ensemble of realizations. In the present analysis, the ensemble spread is based on uncertainties arising from the auxiliary variables as well as from the spatial distribution of stations.</p><p>Cross-validation is used to tune the GPR hyper parameters. Where conventional GPR hyperparameter tuning aims at an optimal prediction of the gridded mean, instead, we tune the GPR hyperparameters for optimal prediction of the gridded ensemble spread.</p><p>Building on our experience with providing similar gridded climate data sets, this set of gridded wind fields is a novel addition to the E-OBS climate data sets.</p>

scholarly journals Crystal structures of (2E)-1-(3-bromothiophen-2-yl)-3-(2-methoxyphenyl)prop-2-en-1-one and (2E)-1-(3-bromothiophen-2-yl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one

2015 ◽  
Vol 71 (8) ◽  
pp. 965-971 ◽  
Author(s):  
Vasant S. Naik ◽  
Venkataraya Shettigar ◽  
Tyler S. Berglin ◽  
Jillian S. Coburn ◽  
Jerry P. Jasinski ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Intramolecular Interaction ◽  
Intramolecular Interactions ◽  
Inversion Symmetry ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Space Group ◽  
Independent Molecules

In the molecules of the title compounds, (2E)-1-(3-bromo-thiophen-2-yl)-3-(2-methoxyphenyl)prop-2-en-1-one, C14H11BrO2S, (I), which crystallizes in the space groupP-1 with four independent molecules in the asymmetric unit (Z′ = 8), and (2E)-1-(3-bromothiophen-2-yl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one, C15H13BrO3S, (II), which crystallizes withZ′ = 8 in the space groupI2/a, the non-H atoms are nearly coplanar. The molecules of (I) pack with inversion symmetry stacked diagonally along thea-axis direction. Weak C—H...Br intramolecular interactions in each of the four molecules in the asymmetric unit are observed. In (II), weak C—H...O, bifurcated three-center intermolecular interactions forming dimers along with weak C—H...π and π–π stacking interactions are observed, linking the molecules into sheets along [001]. A weak C—H...Br intramolecular interaction is also present. There are no classical hydrogen bonds present in either structure.

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