Synthesis of monolayer platinum nanosheets Funatsu, A; Tateishi, H; Hatakeyama, K ...
Chemical communications (Cambridge, England),
08/2014, Letnik:
50, Številka:
62
Journal Article
Recenzirano
Platinum (Pt) nanosheets were developed by exfoliating layered platinum oxide. Moreover, we succeeded in synthesizing monolayer Pt nanosheets for the first time by adjusting the conditions for ...reduction. Monolayer Pt nanosheets were highly active in oxygen reduction reaction.
Geophysical properties of oceanic crust are strongly influenced by the presence of cracks. We studied the effects of cracks on the physical properties of oceanic crustal rocks collected from the ICDP ...Oman Drilling Project Hole GT3A. Electrical resistivity and P‐ and S‐wave velocities were measured under dry and brine‐water‐saturated conditions for each sample. The experimental results reveal that electrical resistivity and elastic wave velocities are differently correlated with porosity. We performed joint inversion of the measured electrical and elastic properties combining an effective medium model by Kachanov and a statistical crack fluid flow model by Guéguen and Dienes with percolation theory. As a result, the variations in electrical and elastic properties can be related to the crack microstructural parameters: crack density and aspect ratio, as well as connectivity of cracks evaluated from crack density. To understand the influence of in situ conditions of oceanic crust, the joint inversion using the proposed cross‐property relationship was performed for geophysical properties obtained by logging measurements at IODP Hole 1256D. Results show the depth variations of resistivity and sonic velocities can be successfully interpreted by decreasing crack porosity and connectivity. Our data and analysis can provide new insights into the interpretation of geophysical data from the oceanic crust at which pore‐fluid plays key roles in various geodynamic activities.
Plain Language Summary
Cracks in the oceanic crust play key roles in subsurface processes, including fluid transportation, heat and chemical exchange, and microbial activity. Therefore, it is important to understand how cracks are distributed in the oceanic crust. Given that cracks exert an important influence on the physical properties of rocks, electrical and seismological surveys have been conducted at various locations in the oceanic plates. However, to quantitatively interpret the geophysical data obtained from these surveys, laboratory investigations are essential. In this study, we measured the electrical resistivity and elastic wave velocity of oceanic crustal rocks collected from drillcores of the Oman ophiolite, in which tectonic fragments of ancient oceanic plate are preserved on land. Our experimental data show that electrical resistivity and elastic wave velocity are differently correlated with porosity. Analysis of these data indicates that the variations in the electrical and elastic properties can be related to crack density, aspect ratio, and crack connectivity. The cross‐property relationship established is applied successfully to in situ geophysical data obtained by borehole logging in oceanic crust. Our data and proposed cross‐property relationship provide new insights into the interpretation of geophysical data from the oceanic crust.
Key Points
We measured the electrical resistivity and elastic wave velocity of the sheeted dike–gabbro transition zone of the Oman Drilling Project
Variation in the electrical and elastic properties of Hole GT3A was interpreted by combining effective medium model and percolation model
Applying the cross‐property relationship to logging data at IODP Hole 1256D, we estimated the crack parameters of in situ oceanic crust
MicroRNA-125b-1 (miR-125b-1) is a target of a chromosomal translocation t(11;14)(q24;q32) recurrently found in human B-cell precursor acute lymphoblastic leukemia (BCP-ALL). This translocation ...results in overexpression of miR-125b controlled by immunoglobulin heavy chain gene (IGH) regulatory elements. In addition, we found that six out of twenty-one BCP-ALL patients without t(11;14)(q24;q32) showed overexpression of miR-125b. Interestingly, four out of nine patients with BCR/ABL-positive BCP-ALL and one patient with B-cell lymphoid crisis that had progressed from chronic myelogenous leukemia overexpressed miR-125b. To examine the role of the deregulated expression of miR-125b in the development of B-cell tumor in vivo, we generated transgenic mice mimicking the t(11;14)(q24;q32) (Eμ/miR-125b-TG mice). Eμ/miR-125b-TG mice overexpressed miR-125b driven by IGH enhancer and promoter and developed IgM-negative or IgM-positive lethal B-cell malignancies with clonal proliferation. B cells obtained from the Eμ/miR-125b-TG mice were resistant to apoptosis induced by serum starvation. We identified Trp53inp1, a pro-apoptotic gene induced by cell stress, as a novel target gene of miR-125b in hematopoietic cells in vitro and in vivo. Our results provide direct evidence that miR-125b has important roles in the tumorigenesis of precursor B cells.
In an analysis of 114 F(2) individuals from a cross between clubroot-resistant and susceptible lines of Brassica rapa L., 'G004' and 'Hakusai Chukanbohon Nou 7' (A9709), respectively, we identified ...two loci, Crr1 and Crr2, for clubroot (caused by Plasmodiophora brassicae Woronin) resistance. Each locus segregated independently among the F(2) population, indicating that the loci reside on a different region of chromosomes or on different chromosomes. Genetic analysis showed that each locus had little effect on clubroot resistance by itself, indicating that these two loci are complementary for clubroot resistance. The resistance to clubroot was much stronger when both loci were homozygous for resistant alleles than when they were heterozygous. These results indicate that clubroot resistance in B. rapa is under oligogenic control and at least two loci are necessary for resistance.
Abstract Aims Vascular invasion is an established adverse prognostic factor in hepatocellular carcinoma (HCC). The aim of the current study was to identify the preoperative predictors of vascular ...invasion in patients undergoing partial hepatectomy for HCC. Methods A retrospective analysis of 227 consecutive patients who underwent partial hepatectomy for HCC was conducted. Vascular invasion was defined as gross or microscopic involvement of the vessels (portal vein or hepatic vein) within the peritumoral liver tissue. Results Seventy-six (33%) patients had vascular invasion. Among the preoperative factors, only the tumour size (relative risk, 16.78; p < 0.01) and the serum α-fetoprotein (AFP) level (relative risk, 3.57; p < 0.01) independently predicted vascular invasion. As the tumour size increased, the incidence of vascular invasion increased: ≤2 cm, 3%; 2.1–3 cm, 20%; 3.1–5 cm, 38%; and >5 cm, 65%. The incidence of vascular invasion was 32% in patients with serum AFP levels ≤1000 ng/mL, compared to 61% in patients with higher serum AFP levels ( p < 0.01). Patients with both tumours >5 cm and serum AFP levels >1000 ng/mL had an 82% incidence of vascular invasion. Conclusions The tumour size and serum AFP level, alone or in combination, are useful in predicting the presence or absence of vascular invasion before hepatectomy for HCC.
Polycrystalline hexagonal ferrites (Y, Z and W-phases) were prepared by the usual ceramic sintering. Their complex permeability spectra were natural resonance type, and numerically separated into ...spin rotational and domain wall motion components. For the spin rotational component, it was found that the Snoek's product values of them were far beyond the product values of spinel ferrite. It enabled us to design thin electromagnetic wave absorbers for the quasimicrowave region.
Abstract Magnetic compression anastomosis (MCA) provides a minimally invasive treatment creating a nonsurgical, sutureless enteric anastomosis in conjunction with an interventional radiologic ...technique by using 2 high-power magnets. Recently, the MCA technique has been applied to bile duct strictures after living donor liver transplantation or major hepatectomy. Herein we described use of MCA for bile duct stenosis 5 months after donor left hepatectomy in a 24-year-old man who presented with a stricture at the porta hepatis and intrahepatic bile duct dilatation. Unsuccessful transpapillary biliary drainage and balloon dilatation through a percutaneous transhepatic biliary drainage (PTBD) route led to the MCA. A 4-mm-diameter cylindrical samarium-cobalt (Sm-Co) daughter magnet with a long nylon wire was placed at the superior site of the obstruction through the PTBD route. A 5-mm-diameter Sm-Co parent magnet with an attached nylon handle was endoscopically inserted into the common bile duct and placed at the inferior site of obstruction. The 2 magnets were attracted, sandwiching the stricture and establishing a reanastomosis. In conclusion, the MCA technique was a unique procedure for choledochocholedochostomy in a patient with bile duct stenosis after donor hepatectomy.
Background: Detailed histochemical analysis of coronary thrombi obtained freshly from acute phase of myocardial infarction patients may provide information necessary to understand the mechanism of ...coronary occlusive thrombus formation. Methods and Results: Coronary thrombi causing myocardial infarction were obtained from 10 consecutive patients of myocardial infarction in the acute phase, using a newly developed aspiration catheter. All the fixed specimens of coronary thrombi, by hematoxylin and eosin staining, were found to contain three major constituents, namely, platelets, densely packed fibrin and inflammatory cells, including polymorphonuclear and mononuclear cells, although their distribution in each specimen is totally heterogeneous. Immunohistochemical staining revealed the prominent presence of von Willebrand factor (VWF) at the sites of platelet accumulation, presence of tissue factor and platelets at the sites of deposition of fibrin fibrils. It also revealed the presence of CD16‐, CD45‐ and CD34‐positive cells, yet the functional roles of these cells have still to be elucidated. There are weak positive correlation between the number of inflammatory cells involved in the unit area of coronary thrombi specimen and the time of collection of the specimens after the onset of chest pain. Conclusions: In spite of various limitations, our results contain information suggesting the possible role of VWF in platelet‐thrombus formation, possible important role played by tissue factor and activated platelets in the formation of fibrin fibrils, and the positive relationship between inflammatory cells migration and the formation of occlusive thrombi in human coronary arteries.
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