846 research outputs found
The curious case of offset bars : markers for a baby galaxy disk or signposts of an interaction with dark matter sub halos?
>Magister Scientiae - MScWe have used the Spitzer Survey of Stellar Structure in Galaxies (S⁴G) as a representative sample of the local universe (total of 2352 galaxies in S⁴G) to make a catalog of offset disk barred galaxies. Using the combined variation of the position angle and the ellipticity (provided by ellipse fit) and also through visual inspection, we have been able to identify all offset structures in S⁴G. While primary bars are present in 2=3 of the disk galaxies in the visible universe, offset bars have a much lower fraction. Of the ̴ 1500 (3.6µm images) disk galaxies available in S⁴G, we classified only 49 as offset barred disk galaxies. We have determined basic properties (bar to total luminosity ratio, bar length, disk scale-length and bars of offset bars shape) using GALFIT, a widely used galaxy decomposition software package. Our main conclusion is that all the offset bars are boxy, independent of their offset from the galaxy center, or the mass of the host galaxy. Additionally we find that, the early type offset bars seem to be more boxy than the late types. The comparison of our offset sample with two other samples, respectively, low mass and high mass normal barred galaxies ("normal" for bars located at the photometric center of the host galaxy), reveals them to be at an intermediate position between the two normal samples. The bar length, disk scale-length and bar to total luminosity ratio are on average larger than the low mass normal and smaller than high mass normal barred galaxies. We have found, overall, a tighter correlation between the disk and bar properties for offset bars in comparison to the two normal samples. Our explanation is that, although the offset has no visible impact on the global shape of the bars, the process responsible for these disturbances seems to affect the star formation rate such that their disk and bars are on average more active than the normal barred galaxies in the same mass range, but not enough to surpass normal barred galaxies with much higher mass
第828回千葉医学会例会・第6回磯野外科例会 88-3.
Western blotting was performed to examine the protein levels of Twist in the indicated cells; β-actin was used as control. (JPG 151 kb
Intramolecular O···H Hydrogen Bonding of Salicylic Acid: Further Insights from O 1s XPS and <sup>1</sup>H NMR Spectra Using DFT Calculations
Intramolecular hydrogen bonding (HB) is a complex phenomenon
that
extends beyond a simple valence event, affecting the core electrons
of a molecule. Salicylic acid (SA) and its conformers provide an excellent
model compound for studying intramolecular HB as the proton donor
(H) and acceptor (O) can be toggled by rotating the C–O and
C–C bonds to form up to seven potential conformers through
various HB. In this study, we computationally investigated intramolecular
interactions in SA conformers with and without such HB, by examining
their calculated O 1s core electron-binding energy (CEBE) and 1H NMR chemical shifts validated using recent measurements.
The quantum mechanically stable SA conformers are fully defined by
three rotatable bonds in the compound, which are abstracted as SA(η1η2η3) digital structures,
where ηi = 0 if the ηi angles match
the most stable SA conformer (000) and ηi = 1 otherwise. Our findings suggest that the stability is
dominated by the appearance of the intergroup intramolecular HB of
Hp···O (where O is in the carboxylic acid
functional group and Hp is the phenolic proton in −OHp), and η3 serves as a switch of such HB.
As a result, the (η1η20) SA conformers
containing such Hp···O HB are more stable
than other SA conformers (η1η21)
without such the Hp···O HB. The present
density functional theory calculations reveal that this Hp···O HB results in splitting of the O 1s CEBEs of
two hydroxyl groups (−OH) by up to 1 eV and deshielding the
Hp proton 1H NMR (δHp) up to
11.68 ppm for the (η1η20) conformers.
Without such Hp···O HB, the O 1s XPS binding
energies of two −OH groups will be closely located in the same
band, and the 1H NMR chemical shift of the Hp atom will be as small as an 4.09 ppm SA conformer [SA-G(101)]. The
present study indicates that the O 1s CEBE splitting between two −OH
groups serves as an indicator of the presence of the Hp···O HB in SA conformers, which is also supported
by the 1H NMR results
Dual-Functional Emulsifying/Antifogging Coumarin-Containing Polymeric Micelle
Dual-functional
emulsifying/antifogging polymeric micelles have
been prepared by the self-assembly of poly(2-(dimethylamino)ethyl
methacrylate-<i>co</i>-methyl methacrylate-<i>co</i>-7-acryloxy-4-methylcoumarin) P(DMAEMA-<i>co</i>-MMA-<i>co</i>-AOM). On one hand, the polymeric micelles have spherical
morphology and exhibit triple responsive behaviors. The sample with
the DMAEMA/MMA/AOM molar ratio of 5/3/3 (T2) is chosen to investigate
the influence of pH on the emulsifying performance, and the configuration
of polymeric micelles on the oil/water interface is investigated.
The amount of micelles arranged on the surface of solidified polymerized
beads gradually decreases as the pH changes from 12 to 5, and then
total phase separation and demulsification occur at pH 3. On the other
hand, we prepare an effective antifogging coating by forming an interchain
network (ICN) resulting from self-assembled micelles and photo-cross-linked
coumarin units. The ICN-T2 coating can not only absorb water vapor
rapidly but also avoid excessive swelling of the amphiphilic terpolymer,
thus leading to excellent antifogging performance. To the best of
our knowledge, the photo-cross-linkable coumarin derivative is first
introduced into an antifogging polymer coating at the molecular level,
successfully avoiding the use of chemical cross-linking agents. The
coumarin-containing polymeric micelle may be applied in many industrial
processes and will provide new insight into the interface or surface
property of macromolecular materials
Dominant Carbons in <i>trans</i>- and <i>cis</i>-Resveratrol Isomerization
A comprehensive
analysis for isomerization of geometric isomers
in the case of resveratrol (R) has been presented. As an important
red wine molecule, only one geometric isomer of resveratrol, i.e., <i>trans</i>-R rather than <i>cis</i>-R, is primarily
associated with health benefit. In the present study, density function
theory (DFT) provides accurate descriptions of isomerization of resveratrol.
The nearly planar <i>trans</i>-R forms a relatively rigid
and less flexible conjugate network, but the nonplanar <i>cis</i>-R favors a more flexible structure with steric through space interaction.
The calculated carbon nuclear magnetic resonance (NMR) chemical shift
indicates that all carbons are different in the isomers; it further
reveals that four carbon sites, i.e., C<sub>(6)</sub>, C<sub>(8)</sub>C<sub>(9)</sub>, and C<sub>(11)</sub>, have a significant
response to the geometric isomerization. Here C<sub>(6)</sub> is related
to the steric effect in <i>cis</i>-R, whereas C<sub>(11)</sub> may indicate the isomerization proton transfer on C<sub>(9)</sub> linking with the resorcinol ring. The excess orbital energy spectrum
(EOES) confirms the NMR “bridge of interest” carbons
and reveals that five valence orbitals of 34<i>a</i>, 35<i>a</i>, 46<i>a</i>, 55<i>a</i>, and 60<i>a</i> respond to the isomerization most significantly. The highest
occupied molecular orbital (HOMO), 60<i>a</i>, of the isomer
pair is further studied using dual space analysis (DSA) for its orbital
momentum distributions, which exhibit p-electron dominance for <i>trans</i>-R but hybridized sp-electron dominance for <i>cis</i>-R. Finally, energy decomposition analysis (EDA) highlights
that <i>trans</i>-R is preferred over <i>cis</i>-R by −4.35 kcal·mol<sup>–1</sup>, due to small
electrostatic energy enhancement of the attractive orbital energy
with respect to the Pauli repulsive energy
Chilling injury symptoms of ‘Hongyang’ kiwifruit.
<p>Representative pictures of ‘Hongyang’ kiwifruit after 90 days of cold storage followed by 5 days of shelf life at 20°C. (A) normal kiwifruit. (B) skin showing the brown symptom of CI (arrow). (C) normal flesh of kiwifruit. (D) flesh of kiwifruit showing the grainy symptom (arrow). (E) the cross-section of the normal flesh. (F) the cross-section of the flesh showing the grainy symptom (arrow). (G)the longitudinal section of the normal flesh. (H) the longitudinal section of the flesh showing the grainy symptom (arrow).</p
Effect of exogenous Put treatment on ethylene production rate of ‘Hongyang’ fruit.
<p>Kiwifruit were respectively immersed in 0 mM (control) and 2 mM putrescine (Put) for 10 min and then storage at 0°C and 90–95% relative humidity for 90 days. In storage time ‘+5’ denotes 5 days of shelf life at 20°C following storage at 0°C. Vertical bars represent standard error of means (n = 3). Asterisks show significant difference (<i>P <0</i>.<i>05</i>) for the samples between 2 mM Put treatment and control taken at the same time point.</p
MOESM1 of Hemodynamics of cerebral bridging veins connecting the superior sagittal sinus based on numerical simulation
Additional file 1. The detail data about the difference between the anterior and posterior segments of bridging vein models
Wind Loads Acting on Clad Scaffolding
This paper was reviewed and accepted by the APCWE-IX Programme Committee for Presentation at the 9th Asia-Pacific Conference on Wind Engineering, University of Auckland, Auckland, New Zealand, held from 3-7 December 2017
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