52 research outputs found
Study on the growth mechanism of the internal oxide layer in 9% Ni cryogenic steel
The oxidation behavior of the Ni-rich layer in the internal oxide layer (IOL) in 9% Ni cryogenic steel is investigated at 1,150°C for 0â240 min in the air atmosphere. The morphology and phase composition of the Niârich layer are analyzed with energy dispersive spectroscopy, scanning electron microscopy, metallographic microscopy, and Xâray diffraction. The results show that the Niârich layer mainly consists of gray Fe3O4/FeO and white NiâFe particles, with a small amount of black Fe2SiO4. The morphologies of NiâFe particles undergo the following changes with isothermal oxidation time: dotâlike â stripâlike â net-like; at the same time, layered NiâFe particles were formed at about 1/3 of the thickness of the Niârich layer. Compared with the dot-like NiâFe particle, the net-like and layered NiâFe particles provide a fast path for the diffusion of O in the Niârich layer. However, the experimental steel still has a much lower oxidation rate because of the hindrance of NiâFe particles on the out-diffusion of Fe. During the oxidation process, the Kirkendall effect induces pores/cavities in the IOL, which weakens the stability of the IOL. In the end, the spalling phenomenon of the layered NiâFe particle occurs at 1,150°C for 180 min
Cross-borehole delineation of a conductive ore deposit in a resistive host-experimental design
Journal ArticleThe finite-difference time-domain method is used for high-resolution full-wave analysis of cross-borehole electromagnetic surveys of buried nickel sulfide deposits. The method is validated against analytical methods for simple cases, but is shown to be a valuable tool for analysis of complicated geological structures such as faulted or layered regions. The magnetic fields generated by a wire loop in a borehole near a nickel sulfide deposit are presented for several cases. The full-wave solution is obtained up to 200 MHz, where quasi-static methods would have failed. The dielectric response is included in the solution, and the diffractive nature of the field is observed. The sensitivity of each receiver in a vertical line in the cross borehole is presented and analyzed to provide an optimal weighting for receivers that can be applied to an experimental study
catena-Poly[[(5-phenyl-2,2âČ-bipyridine-Îș2 N,NâČ)copper(I)]-ÎŒ-thioÂcyanido-Îș2 N:S]
The title compound, [Cu(NCS)(C16H12N2)]n, was synthesised under hydroÂthermal conditions. The CuI ion shows distorted tetraÂhedral geometry being coordinated by two N atoms from a 5-phenyl-2,2âČ-bipyridine ligand and by the N and S atoms from two different thioÂcyanate anions. The CuI ions are bridged by thioÂcyanide groups, forming a one-dimensional coordination polymer along the b axis. The crystal packing is through van der Waals contacts and CâHâŻÏ interÂactions
Poly[pentaÂkisÂ(ÎŒ-cyanido-Îș2 N:C)trisÂ(5-phenyl-2,2âČ-bipyridine-Îș2 N,NâČ)pentaÂcopper(I)]
The hydroÂthermal reaction of Cu(acetate)2 and K3[Fe(CN)6] with 5-phenyl-2,2âČ-bipyridine (5-ph-2,2âČ-bpy) in water yields the polymeric title complex, [Cu5(CN)5(C16H12N2)3]n, which consists of ribbons along the a axis, constructed from 26-membered {Cu10(CN)8} rings. In these rings, the metal atoms are bridged by cyanide groups, except for one close CuâŻCu contact [2.7535â
(12)â
Ă
], which can be considered as ligand-unsupported. Within the rings, one Cu atom has a distorted tetraÂhedral geometry through the coordination to two N atoms from 5-ph-2,2âČ-bpy and two N/C atoms from two cyanide groups. Two Cu atoms have a trigonal planar environment being coordinated by three cyanide groups and two other Cu atoms have a distorted square planar geometry through coordination to two N atoms from 5-ph-2,2âČ-bpy and two N/C atoms from two cyanide groups
Physicochemical and biological properties of a novel injectable polyurethane system for root canal filling
Genome-Wide Network-Based Analysis of Colorectal Cancer Identifies Novel Prognostic Factors and an Integrative Prognostic Index
Background/Aims: Colorectal cancer (CRC) is one of leading cancers in both incidence and mortality rate. The 5-year survival rate varies considerably depending on the pathological stage of the tumor. Although prominent progress has been made through screening for survival-associated factors from a certain type of genetic or epigenetic modifications, few attempts have been made to apply a network-based approach in prognostic factor identification, which could prove valuable for a complex, multi-faceted disease such as CRC. Methods: In this study, a TCGA dataset of 379 CRC patients was subjected to a network-based analysis strategy consisting of multivariate regression, co-expression network and gene regulatory network analyses, and survival analyses. Both genetic and epigenetic aberrations, including those in gene expression and DNA methylation at specific sites, were screened for significant association with patient survival. A prognostic index (PI) integrating all potential prognostic factors was subsequently validated for its prognostic value. Results: A collection of six miRNAs, eleven mRNAs, and nine DNA methylation sites were identified as potential prognostic factors. The low- and high-risk patient groups assigned based on PI level showed significant difference in overall survival (hazard ratio = 1.32, 95% confidence interval 1.29-1.36, p < 0.0001). Patients in the low- and high-risk groups can be further divided into a total of four subgroups, based on pathological staging. In the two high-risk subgroups (PI > 0), there was significant different (Cox p < 0.0001) in OS between the earlier (stages I/II) and later stages (stages III/IV). However, in the two low-risk subgroups (PI < 0), earlier (stages I/II) and later stages (stages III/IV) showed no significant difference in OS (Cox p = 0.185). On the other hand, there were significant differences in OS between the low- and high-risk subgroups when both subgroups were of earlier stages (Cox p < 0.001) or of later stages (Cox p < 0.0001). Conclusion: The novel network-based, integrative analysis adopted in this study was efficient in screening for prognostic predictors. Along with PI, the set of 6 miRNAs, 11 mRNAs, and 9 DNA methylation sites could serve as the basis for improved prognosis estimation for CRC patients in future clinical practice
Instrument development and validation of the stroke pre-hospital delay behavior intention scale in a Chinese urban population
Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial
Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18â85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25â75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300â5000 mg/g who had received maximum labelled or tolerated reninâangiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for â„30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for â„90 days, chronic dialysis for â„90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4â2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49â0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85â2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75â1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie
Roles of Oxidative Stress in Polycystic Ovary Syndrome and Cancers
Oxidative stress (OS) has received extensive attention in the last two decades, because of the discovery that abnormal oxidation status was related to patients with chronic diseases, such as diabetes, cardiovascular, polycystic ovary syndrome (PCOS), cancer, and neurological diseases. OS is considered as a potential inducing factor in the pathogenesis of PCOS, which is one of the most common complex endocrine disorders and a leading cause of female infertility, affecting 4%â12% of women in the world, as OS has close interactions with PCOS characteristics, just as insulin resistance (IR), hyperandrogenemia, and chronic inflammation. It has also been shown that DNA mutations and alterations induced by OS are involved in cancer pathogenesis, tumor cell survival, proliferation, invasion, angiogenesis, and so on. Furthermore, recent studies show that the females with PCOS are reported to have an increasing risk of cancers. As a result, the more serious OS in PCOS is regarded as an important potential incentive for the increasing risk of cancers, and this study aims to analyze the possibility and potential pathogenic mechanism of the above process, providing insightful thoughts and evidences for preventing cancer potentially caused by PCOS in clinic
The Study on Large-Diameter Drilling Prevention Method of Rock Burst in the Xinxing Coal
Based on the engineering background, the 41051 working face of the 65th coal mine in Qitaihe Xinxing Mine was regarded as the engineering background, by using of the comprehensive research methods such as theoretical analysis and calculation, FLAC3D numerical simulation, physical parameters of coal and rock in laboratory, and the field industrial measurement, to research on the large drilling relieving rock burst mechanism and parameter setting in reasonable. The distribution of stress and plastic zone in drilling surrounding rock and its influence parameters are clarified, and the distribution of the âbutterfly plastic zoneâ and the mutation condition of the âbutterfly plastic zoneâ in trigger stress state are explored. On the basis, combined with theoretical analysis and numerical simulation, studying the rock burst prevention and treatment mechanism in large drilling, through the statistics of the Xinxing mine pressure characteristics, the measurement of the physical parameters of coal and rock and the test of ground stress finding is that the coal satisfies âThree hardâ condition in Xinxing mine and is affected by larger horizontal tectonic stress. Combined with the real geological conditions, the layout parameters of relief pressure large drilling are simulated, and the result shows that the drilling of 600 diameters and 10âm pitch of hole and throughout the working face is reasonable, and the effect is obvious about pressure relief. For the practical implementation, the electromagnetic radiation monitoring is used to evaluate the effect in field; to comprehensive analysis, the relief pressure large drilling has obvious control effect to the 41051 workface rock burst
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