182 research outputs found
第831回千葉医学会例会・第15回千葉大学放射線医学教室例会
Figure S2. All a-DMRs within (1) genomic location. Top: a-DMRs (purple), gene, DHS clusters, transcription factor ChIP-seq, ChromHMM segmentation, combined segmentation and conservation; and (2) scatterplot: x-axis = Age, y-axis = Normalised methylation. (PDF 34909 kb
Late Devonian closure of the North Qilian Ocean: evidence from detrital zircon U–Pb geochronology and Hf isotopes in the eastern North Qilian Orogenic Belt
<div><p>The closure age of the North Qilian Ocean, which lay between the Alashan Terrane and Central Qilian Block during the early Palaeozoic, is intensely debated. This article presents a provenance study of detrital materials from three Upper Devonian sedimentary formations in the Pingchuan area of Gansu Province in the eastern North Qilian Orogenic Belt (NQOB), to constrain the tectonic evolution of the belt. U–Pb dating and Lu–Hf isotopic studies were conducted on detrital zircons from samples of sedimentary rocks. Four age populations of U–Pb zircon ages are defined as: 0.5–0.4 Ga (peak at 472 Ma); 0.8–1.3 Ga (peaks at 960 Ma and 1102 Ma); 1.8–2.1 Ga (two prominent peaks at 1963 Ma and 2045 Ma, and two subordinate peaks at 1816 Ma and 2168 Ma); and 2.4–2.5 Ga (peak at 2495 Ma). Zircons with U–Pb age spectra of 1.8–2.1 Ga and their corresponding εHf(t) values are markedly different from those of the North China Block, Dunhuang Terrane, and Central Qilian Block, but have a strong similarity to zircons from the Alashan Terrane. Furthermore, zircons with ages ranging from 1.8 to 2.1 Ga are reported for the first time in early Palaeozoic strata of the eastern NQOB. The presence of Alashan-derived clasts in the Upper Devonian strata in the NQOB indicates that the sediments were deposited after amalgamation between the Alashan and Qilian terranes. Combined with previous geochronological and geochemical data from the early Palaeozoic igneous and sedimentary rocks, we propose that the closure of the North Qilian Ocean occurred in the Late Devonian. The similar age spectra of detrital zircons from sediments of the Alashan, Cathaysia, and Australia imply that the Alashan–Qilian–Qaidam block was probably located in the periphery of Gondwana in the early Palaeozoic.</p></div
Cyclic AMP signalling pathways in the regulation of uterine relaxation-0
<p><b>Copyright information:</b></p><p>Taken from "Cyclic AMP signalling pathways in the regulation of uterine relaxation"</p><p>http://www.biomedcentral.com/1471-2393/7/S1/S10</p><p>BMC Pregnancy and Childbirth 2007;7(Suppl 1):S10-S10.</p><p>Published online 1 Jun 2007</p><p>PMCID:PMC1892051.</p><p></p>l cyclase (ADCY) which converts ATP to cAMP. The levels of cAMP are tightly regulated by phosphodiesterases (PDE), especially PDE4 isoforms. It is thought that cAMP induces uterine relaxation via activation of a specific protein kinase (PRKA) which phosphorylates and inhibits myosin light chain kinase (MYLK). PRKA may also oppose the effect of stimulatory receptors which operate through the phospholipase C (PLC)/calcium pathway. However the precise targets for PRKA phosphorylation in human myometrium are under investigation ( stimulation, inhibition
Covalent cum Noncovalent Functionalizations of Carbon Nanotubes for Effective Reinforcement of a Solution Cast Composite Film
Although carbon nanotubes have impressive tensile properties,
exploiting
these properties in composites, especially those made by the common
solution casting technique, seems to be elusive thus far. The reasons
could be partly due to the poor nanotube dispersion and the weak nanotube/matrix
interface. To solve this dual pronged problem, we combine noncovalent
and covalent functionalizations of nanotubes in a single system by
the design and application of a novel dispersant, hydroxyl polyimide-<i>graft</i>-bisphenol A diglyceryl acrylate (PI<sub>OH</sub>-BDA),
and use them with epoxidized single-walled carbon nanotubes (O-SWNTs).
Our novel PI<sub>OH</sub>-BDA dispersant functionalizes the nanotubes
noncovalently to achieve good dispersion of the nanotubes because
of the strong π–π interaction due to main chain
and steric hindrance of the BDA side chain. PI<sub>OH</sub>-BDA also
functionalizes O-SWNTs covalently because it reacts with epoxide groups
on the nanotubes, as well as the cyanate ester (CE) matrix used. The
resulting solution-cast CE composites show 57%, 71%, and 124% increases
in Young’s modulus, tensile strength, and toughness over neat
CE. These values are higher than those of composites reinforced with
pristine SWNTs, epoxidized SWNTs, and pristine SWNTs dispersed with
PI<sub>OH</sub>-BDA. The modulus and strength increase per unit nanotube
weight fraction, i.e., d<i>E</i>/d<i>W</i><sub>NT</sub> and dσ/d<i>W</i><sub>NT</sub>, are 175 GPa
and 7220 MPa, respectively, which are significantly higher than those
of other nanotube/thermosetting composites (22–70 GPa and 140–3540
MPa, respectively). Our study indicates that covalent cum noncovalent
functionalization of nanotubes is an effective tool for improving
both the nanotube dispersion and nanotube/matrix interfacial interaction,
resulting in significantly improved mechanical reinforcement of the
solution-cast composites
Extraction and Quantitation of Ketones and Aldehydes from Mammalian Cells Using Fluorous Tagging and Capillary LC-MS
The extraction and quantitation of
carbonyl metabolites from cell
lysate was accomplished using a carbonyl-reactive fluorous tag and
capillary liquid chromatography coupled to mass spectrometry (capLC-MS).
Selective fluorous tagging for ketones and aldehydes provided a 30-fold
increase in sensitivity using electrospray ionization MS. Separation
of fluorous tagged carbonyl resulted in good separation of all components,
and tandem MS was able to differentiate structural carbonyl isomers.
The average limit of detection for carbonyl standards was 37 nM (range
1.5–250 nM), with linearity of <i>R</i><sup>2</sup> > 0.99. Reproducibility for metabolites in cell lysate averaged
9% RSD. Human aortic endothelial cells (HAECs) were exposed to varying
levels of glucose, and their carbonyl metabolite levels were quantified.
Significant metabolite changes were seen in glycolysis and the propanoate
pathway from a glucose challenge. Using an untargeted approach, 120
carbonyl metabolites were found to change in hyperglycemic HAECs.
From this list of compounds, multiple metabolites from the pentose
phosphate and tryptophan metabolic pathways were discovered. This
system provides excellent sensitivity and quantitation of carbonyl
metabolites without the need for isotope standards or labels
Structural Coloration of Colloidal Fiber by Photonic Band Gap and Resonant Mie Scattering
Because
structural color is fadeless and dye-free, structurally
colored materials have attracted great attention in a wide variety
of research fields. In this work, we report the use of a novel structural
coloration strategy applied to the fabrication of colorful colloidal
fibers. The nanostructured fibers with tunable structural
colors were massively produced by colloidal electrospinning. Experimental
results and theoretical modeling reveal that the homogeneous and noniridescent
structural colors of the electrospun fibers are caused by two phenomena:
reflection due to the band gap of photonic structure and Mie scattering
of the colloidal spheres. Our unprecedented findings show promise
in paving way for the development of revolutionary dye-free technology
for the coloration of various fibers
Rh(I)-catalyzed Pauson-Khand-type Cycloaddition Reaction of Ene-vinylidenecyclopropanes with Carbon Monoxide (CO)
An intramolecular Pauson-Khand type cycloaddition reaction of ene-vinylidenecyclopropanes with carbon monoxide has been established by using [Rh(COD)Cl]<sub>2</sub> as the catalyst. The reaction was found to be highly efficient in solvents of 1,2-dichloroethane and 1,1,2,2-tetrachloroethane to give excellent yields of 90–99%. The reaction provides easy access to a series of fused 6,5-ring structures containing spiro-cyclopropane units that are useful for drug design and development. A mechanism of this cycloaddition process has been proposed accounting for structures of resulting products that were unambiguously assigned by X-ray diffractional analysis
“Photochemical Surgery” of 1D Metal–Organic Frameworks with a Site-Selective Solubilization/Crystallization Strategy
One-dimensional (1D) hybrid MOFs are attractive if they
consist
of different MOF blocks with interconnected channels. However, the
precision synthesis of such 1D multiblock MOFs with the desired block
lengths and sequences remains a formidable challenge. Herein we propose
the “photochemical surgery” method, which combines top-down
and bottom-up approaches to enable the site-selective solubilization
(removal)/crystallization (reconstruction) of 1D MOFs. We employed
photoreactive MOFs, which were prepared by complexing either Cd2+ or Zn2+ with a mixture containing a photochromic
bispyridyl ligand (PyDTEopen or PyDTZEopen) and an isophthalate (5-nitroisophthalate (nip2–) or 5-bromoisophthalate (bip2–)).
These MOFs were obtained as high-aspect-ratio, needlelike, colorless
crystals that bore 1D channels oriented parallel to the long needle
axis. When photoreactive DTECdMOFNO2 ([Cd(nip)(PyDTEopen)(H2O)]n), for example, was immobilized at both ends
with a metal alloy on a glass substrate and exposed to UV light through
a photomask for 60 min in N,N-dimethylformamide/methanol
(DMF/MeOH), the unmasked part was removed via solubilization to produce
a 50 μm gap. The resulting specimen was immersed for 24 h at
25 °C in DMF/MeOH containing the necessary components for the
construction of DTZECdMOFNO2 ([Cd(nip)(PyDTZEopen)(H2O)]n). Eventually, the gap was filled with DTZECdMOFNO2 to produce a triblock hybrid MOF (DTECdMOFNO2–DTZECdMOFNO2–DTECdMOFNO2). The result of a guest diffusion experiment confirmed
that the newly formed DTZECdMOFNO2 block shared its 1D channels with the host DTECdMOFNO2 blocks. “Photochemical surgery”
can be applied to synthesize 1D hybrid MOFs bearing unconventional
sequences and morphologies, e.g., honeycomb- and inverted-honeycomb-patterned
hybrids
“Photochemical Surgery” of 1D Metal–Organic Frameworks with a Site-Selective Solubilization/Crystallization Strategy
One-dimensional (1D) hybrid MOFs are attractive if they
consist
of different MOF blocks with interconnected channels. However, the
precision synthesis of such 1D multiblock MOFs with the desired block
lengths and sequences remains a formidable challenge. Herein we propose
the “photochemical surgery” method, which combines top-down
and bottom-up approaches to enable the site-selective solubilization
(removal)/crystallization (reconstruction) of 1D MOFs. We employed
photoreactive MOFs, which were prepared by complexing either Cd2+ or Zn2+ with a mixture containing a photochromic
bispyridyl ligand (PyDTEopen or PyDTZEopen) and an isophthalate (5-nitroisophthalate (nip2–) or 5-bromoisophthalate (bip2–)).
These MOFs were obtained as high-aspect-ratio, needlelike, colorless
crystals that bore 1D channels oriented parallel to the long needle
axis. When photoreactive DTECdMOFNO2 ([Cd(nip)(PyDTEopen)(H2O)]n), for example, was immobilized at both ends
with a metal alloy on a glass substrate and exposed to UV light through
a photomask for 60 min in N,N-dimethylformamide/methanol
(DMF/MeOH), the unmasked part was removed via solubilization to produce
a 50 μm gap. The resulting specimen was immersed for 24 h at
25 °C in DMF/MeOH containing the necessary components for the
construction of DTZECdMOFNO2 ([Cd(nip)(PyDTZEopen)(H2O)]n). Eventually, the gap was filled with DTZECdMOFNO2 to produce a triblock hybrid MOF (DTECdMOFNO2–DTZECdMOFNO2–DTECdMOFNO2). The result of a guest diffusion experiment confirmed
that the newly formed DTZECdMOFNO2 block shared its 1D channels with the host DTECdMOFNO2 blocks. “Photochemical surgery”
can be applied to synthesize 1D hybrid MOFs bearing unconventional
sequences and morphologies, e.g., honeycomb- and inverted-honeycomb-patterned
hybrids
Data_Sheet_1_Effect of low-intensity transcranial ultrasound stimulation on theta and gamma oscillations in the mouse hippocampal CA1.docx
Previous studies have demonstrated that low-intensity transcranial ultrasound stimulation (TUS) can eliminate hippocampal neural activity. However, until now, it has remained unclear how ultrasound modulates theta and gamma oscillations in the hippocampus under different behavioral states. In this study, we used ultrasound to stimulate the CA1 in mice in anesthesia, awake and running states, and we simultaneously recorded the local field potential of the stimulation location. We analyzed the power spectrum, phase-amplitude coupling (PAC) of theta and gamma oscillations, and their relationship with ultrasound intensity. The results showed that (i) TUS significantly enhanced the absolute power of theta and gamma oscillations under anesthesia and in the awake state. (ii) The PAC strength between theta and gamma oscillations is significantly enhanced under the anesthesia and awake states but is weakened under the running state with TUS. (iii) Under anesthesia, the relative power of theta decreases and that of gamma increases as ultrasound intensity increases, and the result under the awake state is opposite that under the anesthesia state. (iv) The PAC index between theta and gamma increases as ultrasound intensity increases under the anesthesia and awake states. The above results demonstrate that TUS can modulate theta and gamma oscillations in the CA1 and that the modulation effect depends on behavioral states. Our study provides guidance for the application of ultrasound in modulating hippocampal function.</p
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