3,480 research outputs found
Magnetic field-induced phase transitions in a weakly coupled s = 1/2 quantum spin dimer system BaCrO
By using bulk magnetization, electron spin resonance (ESR), heat capacity,
and neutron scattering techniques, we characterize the thermodynamic and
quantum phase diagrams of BaCrO. Our ESR measurements indicate that
the low field paramagnetic ground state is a mixed state of the singlet and the
S = 0 triplet for . This suggests the presence of an intra-dimer
Dzyaloshinsky-Moriya (DM) interaction with a DM vector perpendicular to the
c-axis
DEDD regulates degradation of intermediate filaments during apoptosis
Apoptosis depends critically on regulated cytoskeletal reorganization events in a cell. We demonstrate that death effector domain containing DNA binding protein (DEDD), a highly conserved and ubiquitous death effector domain containing protein, exists predominantly as mono- or diubiquitinated, and that diubiquitinated DEDD interacts with both the K8/18 intermediate filament network and pro–caspase-3. Early in apoptosis, both cytosolic DEDD and its close homologue DEDD2 formed filaments that colocalized with and depended on K8/18 and active caspase-3. Subsequently, these filamentous structures collapsed into intracellular inclusions that migrated into cytoplasmic blebs and contained DEDD, DEDD2, active caspase-3, and caspase-3–cleaved K18 late in apoptosis. Biochemical studies further confirmed that DEDD coimmunoprecipitated with both K18 and pro–caspase-3, and kinetic analyses placed apoptotic DEDD staining prior to caspase-3 activation and K18 cleavage. In addition, both caspase-3 activation and K18 cleavage was inhibited by expression of DEDDΔNLS1-3, a cytosolic form of DEDD that cannot be ubiquitinated. Finally, siRNA mediated DEDD knockdown cells exhibited inhibition of staurosporine-induced DNA degradation. Our data suggest that DEDD represents a novel scaffold protein that directs the effector caspase-3 to certain substrates facilitating their ordered degradation during apoptosis
A Flanking Gene Problem Leads to the Discovery of a Gprc5b Splice Variant Predominantly Expressed in C57Bl/6J Mouse Brain and in Maturing Neurons
Gprc5b, a retinoic acid-inducible orphan G protein-coupled receptor (GPCR), is a member of the group C metabotropic glutamate receptor family proteins possibly involved in non-canonical Wnt signaling. Many GPCR transcripts are alternatively spliced, which diversifies this class of proteins in their cell- and tissue-specific signaling, regulatory and/or pharmacological properties. We previously generated p97FE65 isoform-specific knockout mice that showed learning/memory deficits. In this study, we further characterized the 97FE65 null mice using cDNA microarray and RT-PCR analyses.We discovered a novel brain-specific C-terminal splice variant of Gprc5b, Gprc5b_v2, which was differentially expressed in p97FE65 wild type and null mouse brains. The null mice were generated in 129/Sv ES cells, and backcrossed to C57Bl/6J for ten generations. We found that expression of Gprc5b_v2 mRNA in the brains of p97FE65 null mice was dramatically down-regulated (more than 20 fold) compared to their wild type littermates. However, expression profiles of Gprc5b variants and SNP analysis surrounding the FE65 locus suggest that the down-regulation is unlikely due to the altered FE65 function, but rather is caused by gene retention from the 129/Sv ES cells. Consistently, in contrast to ubiquitously expressed Gprc5b_v1, Gprc5b_v2 was predominantly expressed in the brain tissues of C57Bl/6J mice. The alternative splicing of the 3' terminal exon also altered the protein coding sequences, giving rise to the characteristic C-termini. Levels of Gprc5b_v2 mRNA were increased during neuronal maturation, paralleling the expression of synaptic proteins. Overexpression of both Gprc5b variants stimulated neurite-like outgrowth in a neuroblastoma cell line.Our results suggest that Gprc5b-v2 may play a role during brain maturation and in matured brain, possibly through the regulation of neuronal morphology and protein-protein interaction. This study also highlights the fact that unexpected gene retention following repeated backcrosses can lead to important biological consequences
Determination of trace metals in environmental water samples by inductively coupled plasma - mass spectrometry (ICP-MS)
Trace metals in water samples, such as tap water, river water, and sea water, were determined by inductively coupled plasma-mass spectrometry (ICP-MS). ICP-MS has sufficient sensitivity to detect even below the concentrations of ppt level, and therefore the samples were not pretreated with a concentration column. Practical samples were diluted by lo-fold with ultrapure water and measured directly by ICP-MS. The measuring time of one sample was 2.5 min, and the data for 30 elements were obtained simultaneously. The concentrations of heavy metals, such as Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sb, and Pb, in the water samples were in the ranges of 0.05~82ng/ml. Zasu river and Sibukawa (sea water) contained various kinds of metals, and the concentration ranges were spread in a wide range; for example, Mg was 25700 ppb and In was 2 ppt. ICP-MS is found to be a useful and a powerful instrument for trace amounts of elements, and can be applied satisfactorily to the environmental water analysis
Physical and kinematical properties of the X-ray absorber in the broad absorption line quasar APM 08279+5255
We have re-analyzed the X-ray spectra of the gravitational lensed
high-redshift BAL QSO APM 08279+5255, observed with the XMM-Newton and Chandra
observatories. Previous studies (Hasinger et al. 2002; Chartas et al. 2002)
detected unusual, highly-ionized iron absorption features, but differed in
their interpretation of these features, regarding the kinematical and
ionization structure. We seek one physical model that can be successfully
applied to both observations. For the first time we have performed detailed
photoionization modeling on the X-ray spectrum of APM 08279+5255. The absorbing
gas in APM 08279+5255 can be represented by a two-absorbers model with column
densities N_H(1)~7x10^{22} cm^-2, N_H(2)~6x10^{22} cm^-2, and ionization
parameters logxi(1)~1.5 and logxi(2)~3, with one of them (the high-ionization
component) outflowing at v~0.18(\pm 0.01)c, carrying large amount of gas out of
the system. We find that the Chandra spectrum of APM 08279+5255 requires the
same Fe/O ratio overabundance (previously) indicated by the XMM-Newton
observation, showing that both absorber components underwent similar chemical
evolution and/or have similar origin.Comment: 12 pages, 7 figures, accepted by A&A at the 13th of June, 200
Three-dimensional Structure of Nylon Hydrolase and Mechanism of Nylon-6 Hydrolysis
This research was originally published in the Journal of Biological Chemistry. Seiji Negoro, Naoki Shibata, Yusuke Tanaka, Kengo Yasuhira, Hiroshi Shibata, Haruka Hashimoto, Young-Ho Lee, Shohei Oshima, Ryuji Santa, Shohei Oshima, Kozo Mochiji, Yuji Goto, Takahisa Ikegami, Keisuke Nagai, Dai-ichiro Kato, Masahiro Takeo and Yoshiki Higuchi. Three-dimensional Structure of Nylon Hydrolase and Mechanism of Nylon-6 Hydrolysis. J. Biol. Chem. 2012; 287, 5079-5090. © the American Society for Biochemistry and Molecular Biolog
The 2016 Academic Emergency Medicine Consensus Conference, Shared Decision Making in the Emergency Department: Development of a Policy-relevant Patient-centered Research Agenda Diagnostic Testing Breakout Session Report.
Diagnostic testing is an integral component of patient evaluation in the emergency department (ED). Emergency clinicians frequently use diagnostic testing to more confidently exclude worst-case diagnoses rather than to determine the most likely etiology for a presenting complaint. Increased utilization of diagnostic testing has not been associated with reductions in disease-related mortality but has led to increased overall healthcare costs and other unintended consequences (e.g., incidental findings requiring further workup, unnecessary exposure to ionizing radiation or potentially nephrotoxic contrast). Shared decision making (SDM) presents an opportunity for clinicians to discuss the benefits and harms associated with diagnostic testing with patients to more closely tailor testing to patient risk. This article introduces the challenges and opportunities associated with incorporating SDM into emergency care by summarizing the conclusions of the diagnostic testing group at the 2016 Academic Emergency Medicine Consensus Conference on SDM. Three primary domains emerged: 1) characteristics of a condition or test appropriate for SDM, 2) critical elements of and potential barriers to SDM discussions on diagnostic testing, and 3) financial aspects of SDM applied to diagnostic testing. The most critical research questions to improve engagement of patients in their acute care diagnostic decisions were determined by consensus
Graduate Teaching Communities of Practice: Fostering a Sense of Belonging and Professional Development for Graduate Students, by Graduate Students
Communities of Practice provide explicit formal recognition for teaching work and serve as a network of pedagogical resources. Communities of Practice create a safe space and a strengthened sense of community. Communities of Practice can be formed anywhere to meet any set of needs but always thrive with members’ agency and institutional support
Material properties of a low contraction and resistivity silicon-aluminum composite for cryogenic detectors
We report on the cryogenic properties of a low-contraction silicon-aluminum
composite, namely Japan Fine Ceramics SA001, to use as a packaging structure
for cryogenic silicon devices. SA001 is a silicon--aluminum composite material
(75% silicon by volume) and has a low thermal expansion coefficient (1/3
that of aluminum). The superconducting transition temperature of SA001 is
measured to be 1.18 K, which is in agreement with that of pure aluminum, and is
thus available as a superconducting magnetic shield material. The residual
resistivity of SA001 is 0.065 , which is considerably
lower than an equivalent silicon--aluminum composite material. The measured
thermal contraction of SA001 immersed in liquid nitrogen is
%, which is
consistent with the expected rate obtained from the volume-weighted mean of the
contractions of silicon and aluminum. The machinability of SA001 is also
confirmed with a demonstrated fabrication of a conical feedhorn array, with a
wall thickness of 100 . These properties are suitable for
packaging applications for large-format superconducting detector devices.Comment: 8 pages, 4 figures, 1 table, accepted for the Journal of Low
Temperature Physics for the LTD19 special issu
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