866 research outputs found
Novel Magnetic and Thermodynamic Properties of Thiospinel Compound CuCrZrS
We have carried out dc magnetic susceptibility, magnetization and specific
heat measurements on thiospinel CuCrZrS. Below 58 K, dc
magnetic susceptibility and magnetization data show ferromagnetic behavior with
a small spontaneous magnetization 0.27 f. u..
In dc magnetic susceptibility, large and weak irreversibilities are observed
below 6 K and in the range
respectively.
We found that there is no anomaly as a peak or step in the specific heat at
.Comment: 11 pages, 4 figure
Атмосфера секретности как один из факторов формирования менталитета населения закрытых городов Урала
Apatite films were deposited onto titanium (Ti) metal substrates by an electrodeposition method under a pulse current. Metastable calcium phosphate solution was used as the electrolyte. The ion concentration of the solution was 1.5 times that of human body fluid, but the solution did not contain magnesium ions at 36.5 °C. We used an average current density of 0.01 A/cm2 and current-on time (TON) equal to current-off time (TOFF) of 10 ms, 100 ms, 1 s, and 15 s. The adhesive strength between apatite and Ti substrates were relatively high at TON = TOFF = 10 ms. It is considered that small calcium phosphate (C–P) crystals with low crystallinity were deposited on the Ti surface without reacting with other C–P crystals, H2O, and HCO3- in the surrounding environment. This resulted in relaxation of the lattice mismatch and enhancement of the adhesive strength between the apatite crystals and Ti substrates
mbonsai: Application Package for Sequence Classification by Tree Methodology
In many applications such as transaction data analysis, the classification of long chains of sequences is required. For example, brand purchase history in customer transaction data is in a form like AABCABAA, where A, B, and C are brands of a consumer product. The decision tree-based package mbonsai is designed to handle sequence data of varying lengths using one or multiple variables of interest as predictor variables. This software package uses tree growing and pruning strategies adopted from C4.5 and CART algorithms, and includes new features for handling sequence data and indexing for classification purpose. The software uses a simple command line program for learning and predicting processes, and has the ability to generate user-friendly graphics depicting decision trees. The underlying C++ codes are designed to efficiently process large data sets in ASCII files. Two examples from transaction data sets are used to illustrate the application of mbonsai
Essential role of Notch signaling in effector memory CD8+ T cell–mediated airway hyperresponsiveness and inflammation
Adoptive transfer of in vivo–primed CD8+ T cells or in vitro–generated effector memory CD8+ T (TEFF) cells restores airway hyperresponsiveness (AHR) and airway inflammation in CD8-deficient (CD8−/−) mice. Examining transcription levels, there was a strong induction of Notch1 in TEFF cells compared with central memory CD8+ T cells. Treatment of TEFF cells with a γ-secretase inhibitor (GSI) strongly inhibited Notch signaling in these cells, and after adoptive transfer, GSI-treated TEFF cells failed to restore AHR and airway inflammation in sensitized and challenged recipient CD8−/− mice, or to enhance these responses in recipient wild-type (WT) mice. These effects of GSI were also associated with increased expression of the Notch ligand Delta1 in TEFF cells. Treatment of sensitized and challenged WT mice with Delta1-Fc resulted in decreased AHR and airway inflammation accompanied by higher levels of interferon γ in bronchoalveolar lavage fluid. These results demonstrate a role for Notch in skewing the T cell response from a T helper (Th)2 to a Th1 phenotype as a consequence of the inhibition of Notch receptor activation and the up-regulation of the Notch ligand Delta1. These data are the first to show a functional role for Notch in the challenge phase of CD8+ T cell–mediated development of AHR and airway inflammation, and identify Delta1 as an important regulator of allergic airway inflammation
Nitric oxide activates ATP-sensitive potassium channels in mammalian sensory neurons: action by direct S-nitrosylation
<p>Abstract</p> <p>Background</p> <p>ATP-sensitive potassium (K<sub>ATP</sub>) channels in neurons regulate excitability, neurotransmitter release and mediate protection from cell-death. Furthermore, activation of K<sub>ATP </sub>channels is suppressed in DRG neurons after painful-like nerve injury. NO-dependent mechanisms modulate both K<sub>ATP </sub>channels and participate in the pathophysiology and pharmacology of neuropathic pain. Therefore, we investigated NO modulation of K<sub>ATP </sub>channels in control and axotomized DRG neurons.</p> <p>Results</p> <p>Cell-attached and cell-free recordings of K<sub>ATP </sub>currents in large DRG neurons from control rats (sham surgery, SS) revealed activation of K<sub>ATP </sub>channels by NO exogenously released by the NO donor SNAP, through decreased sensitivity to [ATP]i.</p> <p>This NO-induced K<sub>ATP </sub>channel activation was not altered in ganglia from animals that demonstrated sustained hyperalgesia-type response to nociceptive stimulation following spinal nerve ligation. However, baseline opening of K<sub>ATP </sub>channels and their activation induced by metabolic inhibition was suppressed by axotomy. Failure to block the NO-mediated amplification of K<sub>ATP </sub>currents with specific inhibitors of sGC and PKG indicated that the classical sGC/cGMP/PKG signaling pathway was not involved in the activation by SNAP. NO-induced activation of K<sub>ATP </sub>channels remained intact in cell-free patches, was reversed by DTT, a thiol-reducing agent, and prevented by NEM, a thiol-alkylating agent. Other findings indicated that the mechanisms by which NO activates K<sub>ATP </sub>channels involve direct S-nitrosylation of cysteine residues in the SUR1 subunit. Specifically, current through recombinant wild-type SUR1/Kir6.2 channels expressed in COS7 cells was activated by NO, but channels formed only from truncated isoform Kir6.2 subunits without SUR1 subunits were insensitive to NO. Further, mutagenesis of SUR1 indicated that NO-induced K<sub>ATP </sub>channel activation involves interaction of NO with residues in the NBD1 of the SUR1 subunit.</p> <p>Conclusion</p> <p>NO activates K<sub>ATP </sub>channels in large DRG neurons via direct S-nitrosylation of cysteine residues in the SUR1 subunit. The capacity of NO to activate K<sub>ATP </sub>channels via this mechanism remains intact even after spinal nerve ligation, thus providing opportunities for selective pharmacological enhancement of K<sub>ATP </sub>current even after decrease of this current by painful-like nerve injury.</p
Simple and Rapid Enzymatic Method for the Synthesis of Single-Strand Oligonucleotides Containing Trifluorothymidine
To investigate the mechanism of trifluorothymidine (TFT)-induced DNA damage, we developed an enzymatic method for the synthesis of single-strand oligonucleotides containing TFT-monophosphate residues. Sixteen-mer oligonucleotides and 14-mer 5′-phosphorylated oligonucleotides were annealed to the template of 25-mer, so as to empty one nucleotide site. TFT-triphosphate was incorporated into the site by DNA polymerase and then ligated to 5′-phosphorylated oligonucleotides by DNA ligase. The synthesized 31-mer oligonucleotides containing TFT residues were isolated from the 25-mer complementary template by denaturing polyacrylamide electrophoresis. Using these single-strand oligonucleotides containing TFT residues, the cleavage of TFT residues from DNA, using mismatch uracil-DNA glycosylase (MUG) of E.coli origin, was compared with that of 5-fluorouracil (5FU) and 5-bromodeoxyuridine (BrdU). The TFT/A pair was not cleaved by MUG, while the other pairs, namely, 5FU/A, 5FU/G, BrdU/A, BrdU/G, and TFT/G, were easily cleaved from each synthesized DNA. Thus, this method is useful for obtaining some site-specifically modified oligonucleotides
Impact of cystic fibrosis transmembrane conductance regulator gene mutation on the occurrence of chronic pancreatitis in Japanese patients
金沢大学医薬保健研究域医学系DNA analyses of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in japanese patients with idiopathic chronic pancreatitis (ICP) were performed to determine the relationship between the CFTR mutation and ICP. The study included patients with alcoholic pancreatitis (n = 20), patients with ICP (n = 20) and healthy volunteers (controls; n = 110). The poly-T region in intron 8 of the CFTR gene was analysed by direct sequencing. The CFTR coding region was screened using single-strand conformational polymorphism and direct sequencing. In the controls, frequencies of the 5T genotype and 5T allele were 4.5% and 3.6%, respectively. The frequency of the 5T genotype was significantly higher in the ICP group (20%) versus controls, but was not significantly different in alcolohol chronic pacreatitis patients (5%). Thus, the CFIR gene mutation, especially the 5T genotype, appears to have some relationship to ICP prevalence in japanese patients independent of cystic fibrosis. Copyright © 2009 Field House Publishing LLP
Homozygosity Mapping on Homozygosity Haplotype Analysis to Detect Recessive Disease-Causing Genes from a Small Number of Unrelated, Outbred Patients
Genes involved in disease that are not common are often difficult to identify; a method that pinpoints them from a small number of unrelated patients will be of great help. In order to establish such a method that detects recessive genes identical-by-descent, we modified homozygosity mapping (HM) so that it is constructed on the basis of homozygosity haplotype (HM on HH) analysis. An analysis using 6 unrelated patients with Siiyama-type α1-antitrypsin deficiency, a disease caused by a founder gene, the correct gene locus was pinpointed from data of any 2 patients (length: 1.2–21.8 centimorgans, median: 1.6 centimorgans). For a test population in which these 6 patients and 54 healthy subjects were scrambled, the approach accurately identified these 6 patients and pinpointed the locus to a 1.4-centimorgan fragment. Analyses using synthetic data revealed that the analysis works well for IBD fragment derived from a most recent common ancestor (MRCA) who existed less than 60 generations ago. The analysis is unsuitable for the genes with a frequency in general population more than 0.1. Thus, HM on HH analysis is a powerful technique, applicable to a small number of patients not known to be related, and will accelerate the identification of disease-causing genes for recessive conditions
- …