334 research outputs found

    Clinical Pathological Analysis of Surgically Resected Superficial Esophageal Carcinoma to Determine Criteria for Deciding on Treatment Strategy

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    We performed a clinical pathological study of conventionally resected superficial esophageal carcinomas since this type of lesion has been increasing, in order to develop criteria of determination for therapeutic strategies. Pathological studies were performed on specimens obtained by radical surgical resection in 133 cases of superficial esophageal cancer. Evaluation was performed in terms of the gross classification of the lesion type, depth of invasion, lymph node metastasis, vascular invasion, size of the lesion, outcome, etc. In 0-I, 0-IIc+0-IIa, and 0-III type submucosal cancer lesions the rate of metastasis to lymph nodes was more than 40%, but in 0-IIa and 0-IIb mucosal cancer cases no lymph node metastasis was observed. 0-IIc type lesions showed a wide range of invasiveness, ranging from m1 to sm3. In cases with m1 or m2 invasion, no lymph node or lymph-vessel invasion was recognized, but in m3, sm1, sm2, and sm3 cases lymph node metastasis was recognized in 12.5%, 22.2%, 44.0% and 47.4%, respectively. In 47% of lesions with a greatest dimension of less than 30 mm invasion was limited to the mucosa. Seventy-two percent of m1 and m2 cases were 30 mm in size or less. Lymph node metastasis was recognized in only 16.7% of cases less than 30 mm in size, but in cases of lesions 30 mm or more the rate of lymph node metastasis was 35.8%. 0-IIb and 0-IIa type lesions are indications for endoscopic esophageal mucosal resection (EEMR), while 0-I, 0-IIc+0-IIa, and 0-III lesions should be candidates for radical surgical resection. In the 0-IIc category, lesions in which the depression is relatively flat and with a finely granular surface are indications for EEMR, but those cases in which the surface of depression shows granules of varying sizes should be treated with radical surgical resection. Cases of 0-IIa type 30 mm or larger in greatest dimension which have a gently sloping protruding margin shoulder or reddening should be treated with caution, but EEMR can be performed first and subsequent therapeutic strategy decided on, based on the pathological findings of the specimen

    Strain Effects on Point Defects and Chain-Oxygen Order-Disorder Transition in 123-Structure Cuprate Superconductors

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    The energetics of Schottky defects in 123 cuprate superconductor series, REBa2Cu3O7\rm REBa_2Cu_3O_7 (where RE = lanthandies) and YAE2Cu3O7\rm YAE_2Cu_3O_7 (AE = alkali-earths), were found to have unusual relations if one considers only the volumetric strain. Our calculations reveal the effect of non-uniform changes of interatomic distances within the RE-123 structures, introduced by doping homovalent elements, on the Schottky defect formation energy. The energy of formation of Frenkel Pair defects, which is an elementary disordering event, in 123 compounds can be substantially altered under both stress and chemical doping. Scaling the oxygen-oxygen short-range repulsive parameter using the calculated formation energy of Frenkel pair defects, the transition temperature between orthorhombic and tetragonal phases is computed by quasi-chemical approximations (QCA). The theoretical results illustrate the same trend as the experimental measurements in that the larger the ionic radius of RE, the lower the orthorhombic/tetragonal phase transition temperature. This study provides strong evidence of the strain effects on order-disorder transition due to oxygens in the CuO chain sites.Comment: In print Phys Rev B (2004

    Relation of n-value to critical current in bent-damaged Bi2223 composite tape

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    AbstractThe relation of n-value to critical current of bent-damaged (Bi,Pb)2Sr2Ca2Cu3O10+δ (Bi2223) composite tape was studied experimentally and analytically. The experimental results showed that, under bending strain, the n-value decreased rather slightly with decreasing critical current in comparison with the data obtained under applied tensile strain. The experimentally observed slight decrease in n-value with critical current under bending strain, and the measured changes in critical current and n-value with increasing bending strain, were described satisfactorily by the presented damage evolution model that correlates the extent of damage to variation of bending strain-induced tensile strain in the core along the thickness direction

    Formation of Nitriles in the Interstellar Medium via Reactions of Cyano Radicals, CN(X 2Σ+), with Unsaturated Hydrocarbons

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    Crossed molecular beam experiments of cyano radicals, CN(X 2Σ+, ν = 0), in their electronic and vibrational ground state reacting with unsaturated hydrocarbons acetylene, C2H2(X 1Σ), ethylene, C2H4(X 1Ag), methylacetylene, CH3CCH(X 1A1), allene, H2CCCH2(X 1A1), dimethylacetylene, CH3CCCH3(X 1A1'), and benzene, C6H6 (X 1A1g), were performed at relative collision energies between 13.3 and 36.4 kJ mol-1 to unravel the formation of unsaturated nitriles in the outflows of late-type AGB carbon stars and molecular clouds. In all reactions, the CN radical was found to attack the π electron density of the hydrocarbon molecule with the radical center located at the carbon atom; the formation of an initial addition complex is a prevalent pathway on all the involved potential energy surfaces. A subsequent carbon-hydrogen bond rupture yields the nitriles cyanoacetylene, HCCCN (X 1Σ+), vinylcyanide, C2H3CN (X 1A'), 1-methylcyanoacetylene, CH3CCCN (X 1A1), cyanoallene, H2CCCH(CN) (X 1A'), 3-methylcyanoacetylene, HCCCH2CN(X 1A'), 1,1-cyanomethylallene, H2CCC(CN)(CH3) (X 1A'), and cyanobenzene, C6H5CN (X 1A1). In case of acetylene and ethylene, a second reaction channel involves a [1, 2]-H atom shift in the initial HCCHCN and H2CCH2CN collision complexes prior to a hydrogen atom release to form cyanoacetylene, HCCCN (X 1Σ+), and vinylcyanide, C2H3CN (X 1A'). Since all these radical-neutral reactions show no entrance barriers, have exit barriers well below the energy of the reactant molecules, and are exothermic, the explicit identification of this CN versus H atom exchange pathway under single collision conditions makes this reaction class a compelling candidate to synthesize unsaturated nitriles in interstellar environments holding temperatures as low as 10 K. This general concept makes it even feasible to predict the formation of nitriles once the corresponding unsaturated hydrocarbons are identified in the interstellar medium. Here HCCCN, C2H3CN, and CH3CCCN have been already observed; since CH3CCH is the common precursor to H2CCCH(CN)/CH3CCCN and the latter isomer has been assigned unambiguously toward TMC-1 and OMC-1, H2CCCH(CN) is strongly expected to be present in both clouds as well. The formation of isonitrile isomers was not observed in our experiments. Since all reactions to HCCNC, C2H3NC, CH3CCNC, H2CCCH(NC), H2CCC(NC)(CH3), and C6H5NC are either endothermic or the exit barrier is well above the energy of the reactants, neutral-neutral reactions of cyano radicals with closed shell unsaturated hydrocarbons cannot synthesize isonitriles in cold molecular clouds. However, in outflow of carbon stars, the enhanced translational energy of both reactants close to the photosphere of the central star can compensate this endothermicity, and isonitriles might be formed in these hotter environments as well

    Residual Strain Dependence on Matrix Structure in RHQ-Nb3Al Wires by Neutron Diffraction Measurement

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    We prepared three types of non-Cu RHQ-Nb3Al wire samples with different matrix structures: an all-Ta matrix,a composite matrix of Nb and Ta with a Ta inter filament, and an all-Nb matrix. Neutron diffraction patterns of the wire samples were measured at room temperature in J-PARC "TAKUMI". To obtain residual strains of materials, we estimated lattice constant a by multi-peak analysis in the wire. Powder sample of each wire was measured, where the powder was considered to be strain-free. The grain size of all the powder samples was below 0.02 mm. For wire sample with the all-Nb matrix, we also obtained lattice spacing d by a single-peak analysis. Residual strains of Nb3Al filament were estimated from the two analysis results and were compared. Result, residual strains obtained from the multi-peak analysis showed a good accuracy with small standard deviation. The multi-peak analysis results for the residual strains of Nb3Al filament in the three samples were all tensile residual strain in the axial direction, they are 0.12%, 0.12%, and 0.05% for the all-Ta matrix, the composite matrix, and the all-Nb matrix, respectively. Difference in the residual strain of Nb3Al filament between the composite and all-Nb matrix samples indicates that type of inter-filament materials show a great effect on the residual strain. In this paper, we report the method of measurement, method of analysis, and results for residual strain in the tree types of non-Cu RHO-Nb3Al wires.Comment: 7 pages, 8 figure

    Pathology of the human pituitary adenomas

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    This article describes pertinent aspects of histochemical and molecular changes of the human pituitary adenomas. The article outlines individual tumor groups with general, specific and molecular findings. The discussion further extends to the unusual adenomas or carcinomas. The description in this article are pertinent not only for the practicing pathologists who are in the position of making proper diagnosis, but also for the pituitary research scientists who engage in solving basic problems in pituitary neoplasms by histochemistry and molecular biology

    The Cause of ‘Weak-Link’ Grain Boundary Behaviour in Polycrystalline Bi2Sr2CaCu2O8 and Bi2Sr2Ca2Cu3O10 Superconductors

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    The detrimental effects of grain boundaries have long been considered responsible for the low critical current densities (J_c) in high temperature superconductors. In this paper, we apply the quantitative approach used to identify the cause of the 'weak-link' grain boundary behaviour in YBa2Cu3O7 [1], to the Bi2Sr2CaCu2O8 and Bi2Sr2Ca2Cu3O10 materials that we have fabricated. Magnetic and transport measurements are used to characterise the grain and grain boundary properties of micro- and nanocrystalline material. Magnetisation measurements on all nanocrystalline materials show non-Bean-like behaviour and are consistent with surface pinning. Bi2Sr2CaCu2O8: Our microcrystalline material has very low grain boundary resistivity (ρ_GB), which is similar to that of the grains (ρ_G) such that ρ_GB≈ρ_G=2×〖10〗^(-5) Ωm (assuming a grain boundary thickness (d) of 1 nm) equivalent to an areal resistivity of ρ_G=2×〖10〗^(-14) Ωm^2. The transport J_c values are consistent with well-connected grains and very weak grain boundary pinning. However, unlike low temperature superconductors in which decreasing grain size increases the pinning along the grain boundary channels, any increase in pinning produced by making the grains in our Bi2Sr2CaCu2O8 materials nanocrystalline was completely offset by a decrease in the depairing current density of the grain boundaries caused by their high resistivity. We suggest a different approach to increasing J_c from that used in LTS materials, namely incorporating additional strong grain and grain boundary pinning sites in microcrystalline materials to produce high J_c values. Bi2Sr2Ca2Cu3O10: Both our micro- and nanocrystalline samples have ρ_GB/ρ_G of at least 10^3. This causes strong suppression of J_c across the grain boundaries, which explains the low transport J_c values we find experimentally. Our calculations show that low J_c in untextured polycrystalline Bi2Sr2Ca2Cu3O10 material is to be expected and the significant effort in the community in texturing samples and removing grain boundaries altogether is well-founded

    Intussusception among Japanese children: an epidemiologic study using an administrative database

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    <p>Abstract</p> <p>Background</p> <p>The epidemiology of intussusception, including its incidence, can vary between different countries. The aim of this study was to describe the epidemiology of childhood intussusception in Japan using data from a nationwide inpatient database.</p> <p>Methods</p> <p>We screened the database for eligible cases ≤ 18 years of age, who were coded with a discharge diagnosis of intussusception (International Classification of Diseases, 10th revision: K-561) between July to December in 2007 and 2008. We then selected cases according to Level 1 of the diagnostic certainty criteria developed by the Brighton Collaboration Intussusception Working Group. We examined the demographics, management, and outcomes of cases, and estimated the incidence of intussusception.</p> <p>Results</p> <p>We identified 2,427 cases of intussusception. There were an estimated 2,000 cases of infantile intussusception annually in Japan, an incidence of 180-190 cases per 100,000 infants. The median age at diagnosis was 17 months, and two-thirds of the patients were male. Treatment with an enema was successful in 93.0% of cases (2255/2427). The remainder required surgery. Secondary cases accounted for 3.1% (76/2427). Median length of hospital stay was 3 days. Of the 2,427 cases, we found 2 fatal cases associated with intussusception.</p> <p>Conclusions</p> <p>This is currently the largest survey of childhood intussusception in Asia using a standardized case definition. Our results provide an estimate of the baseline risk of intussusception in Japan, and it is higher than the risk observed in other countries.</p

    HER2 testing on core needle biopsy specimens from primary breast cancers: interobserver reproducibility and concordance with surgically resected specimens

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    <p>Abstract</p> <p>Background</p> <p>Accurate evaluation of human epidermal growth factor receptor type-2 (HER2) status based on core needle biopsy (CNB) specimens is mandatory for identification of patients with primary breast cancer who will benefit from primary systemic therapy with trastuzumab. The aim of the present study was to validate the application of HER2 testing with CNB specimens from primary breast cancers in terms of interobserver reproducibility and comparison with surgically resected specimens.</p> <p>Methods</p> <p>A total of 100 pairs of archival formalin-fixed paraffin-embedded CNB and surgically resected specimens of invasive breast carcinomas were cut into sections. All 100 paired sections were subjected to HER2 testing by immunohistochemistry (IHC) and 27 paired sections were subjected to that by fluorescence in situ hybridization (FISH), the results being evaluated by three and two observers, respectively. Interobserver agreement levels in terms of judgment and the concordance of consensus scores between CNB samples and the corresponding surgically resected specimens were estimated as the percentage agreement and κ statistic.</p> <p>Results</p> <p>In CNB specimens, the percentage interobserver agreement of HER2 scoring by IHC was 76% (κ = 0.71) for 3 × 3 categories (0-1+ <it>versus </it>2+ <it>versus </it>3+) and 90% (κ = 0.80) for 2 × 2 categories (0-2+ <it>versus </it>3+). These levels were close to the corresponding ones for the surgically resected specimens: 80% (κ = 0.77) for 3 × 3 categories and 92% (κ = 0.88) for 2 × 2 categories. Concordance of consensus for HER2 scores determined by IHC between CNB and the corresponding surgical specimens was 87% (κ = 0.77) for 3 × 3 categories, and 94% (κ = 0.83) for 2 × 2 categories. Among the 13 tumors showing discordance in the mean IHC scores between the CNB and surgical specimens, the results of consensus for FISH results were concordant in 11. The rate of successful FISH analysis and the FISH positivity rate in cases with a HER2 IHC score of 2+ differed among specimens processed at different institutions.</p> <p>Conclusion</p> <p>It is mandatory to study HER2 on breast cancers, and either CNB or surgical specimen can be used.</p
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