Search Results - (Author, Cooperation:C. Ju)

2015-03-07

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Diamond/chemistry ; Electron Spin Resonance Spectroscopy/*methods ; Mad2 Proteins/chemistry ; Microscopy, Atomic Force ; Molecular Imaging/*methods ; Motion ; Nitrogen/chemistry ; Polylysine/chemistry ; Proteins/*chemistry ; Spin Labels

2014-05-17

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Arabidopsis/genetics/*metabolism ; Arabidopsis Proteins/genetics/*metabolism ; Cell Membrane/*metabolism ; Membrane Proteins/genetics/*metabolism ; *Protein Interaction Maps ; Signal Transduction ; Two-Hybrid System Techniques

2018-06-06

Institute of Physics (IOP)

1367-2630

Physics

2018-05-07

BMJ Publishing

2044-6055

Medicine

Open access, Gastroenterology and hepatology

1524-4741

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: Early local disease recurrence and distant metastasis remain major problems in the management of locally advanced breast carcinoma (LABC). Glutathione S-transferase of the pi class (GST-pi) has been implicated as a potential prognostic predictor for breast carcinomas, and its expression has been reported in 40–70% of untreated human primary breast cancers.We examined GST-pi expression by immunohistochemis-try technique in 45 prechemotherapy biopsy samples and 26 postchemotherapy resection samples from patients with LABC and evaluated its relationship with response to treatment, disease recurrence, and other known prognostic factors. GST-pi expression was present in 56% and 58% of prechemotherapy and postchemotherapy samples, respectively. Of 26 postchemotherapy tumor samples, 15 cases showed positive GST-pi staining; these 15 patients had shorter overall survival times compared with the 11 patients whose tissue samples showed negative staining (p = 0.053). Eight cases showed a marked increase (more than double) of GST-pi expression from prechemotherapy samples to postchemotherapy samples, however, the increase did not correlate with survival time, response rate, or relapse rate. Our findings suggest that evaluation of GST-pi expression after induction chemotherapy for LABC may allow selection of patients who might benefit from different chemotherapeutic regimens or adjuvant chemotherapy.?

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Third harmonic generation (THG) has been performed in reflection from thin polycrystalline films of chloro-gallium and fluoro-aluminum phthalocyanines. By comparison to THG from the 100 surface of silicon, the values of χ(3) are estimated to be 2.5×10−11 and 5×10−11 esu, respectively. The patterns of the molecular and crystal tensors are discussed for the case of multiple resonance enhancements.

Electronic Resource

0003-2670

Ferrocene ; Induced charging current ; Voltammetry

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1365-2842

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The present work is a study of the microstructure, mechanical properties and corrosion behaviour of a series of binary Ti–Nb alloys with Nb contents up to 35 wt%, with emphasis placed on the structure–property relationship of the alloys. The results indicate that crystal structure and morphology of the Ti–Nb alloys are sensitive to the Nb content. The cast c.p. Ti has a hexagonal α phase with a lath type morphology. The alloys containing 15 wt% or less Nb are dominated by a hexagonal α′ phase with an acicular, martensitic structure. When containing 17·5–25 wt% Nb, the alloys are primarily comprised of an orthorhombic α′′ phase. With 27·5 wt% Nb, metastable β phase starts to be retained. With Nb contents higher than 30 wt%, the equi-axed β phase is almost entirely retained. Small amounts of ω phase are detected in alloys containing 27·5 and 30 wt% Nb. Among all present alloys, Ti–10Nb and Ti–27·5Nb exhibit the highest strengths, while the α′′-dominated (17·5 and 20Nb) and β-dominated (〉 30Nb) alloys have the lowest moduli. All Ti–Nb alloys show excellent corrosion resistance in Hank's solution at 37 °C. From the present data, the microhardness, bending strength and modulus of the various phases in Ti–Nb alloys are compared and tentatively summarized as follows:Microhardness: ω 〉 α′ 〉 α′′ 〉 β 〉 α (c.p. Ti)Bending strength: ω 〉 α′ 〉 α′′ 〉 β 〉 α (c.p. Ti)Bending modulus: ω 〉 α (c.p. Ti) 〉 α′ 〉 α′′ 〉 β

Electronic Resource

0924-4247

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Electrical Engineering, Measurement and Control Technology

Electronic Resource

0257-8972

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Electronic Resource

0042-207X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Electronic Resource

0040-6090

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1573-4838

Springer Online Journal Archives 1860-2000

Medicine

Technology

Abstract A series of hydroxyapatite/bioactive glass (HA/BG) coatings have been plasma-sprayed on Ti6Al-4V substrate using HA/BG powders that were prepared by both sinter-granulation and direct mixing methods. The morphology and immersion behavior of these coatings in a simulated body fluid (SBF) were investigated. The results showed that in-house fabricated BG and sinter-granulated HA powders were irregularly shaped and dense. When 5 wt % or more BG was added in HA, the powder became rough and porous. X-ray diffraction (XRD) patterns showed that the presence of BG enhanced the decomposition of HA structure during fabrication of the powders. Reasonably high bond strengths were obtained from all coatings. The granulated type HA/BG coatings showed no significant differences in bond strength from the mixed type HA/BG coatings. The plasma spray process itself and the presence of BG enhanced the decomposition of apatite. Surface morphology of all sinter-granulated type coatings was similar to that of monolithic HA coating, that was comprised of patches of smooth and shiny glassy film and irregularly-shaped particles on its surface. The dissolution depth of plasma-sprayed coatings immersed in SBF was largely dependent on the type and composition of the coating. Granulated type HA/BG coatings were much less dissolvable than monolithic HA or mixed type HA/BG coatings. It seems that the presently used granulation method for the preparation of HA/BG powders plays a predominant role in determining the dissolution behavior of the plasma-sprayed coatings. ©©2000 Kluwer Academic Publishers

Electronic Resource

1573-4838

Springer Online Journal Archives 1860-2000

Medicine

Technology

Hydroxyapatite (HA)-coated Ti6Al4V has recently been used as a bone substitute in orthopaedic and dental applications because of its favourable bioactivity and mechanical properties. Studies in the literature have shown that the bioactivity of calcium phosphate bioactive glass (BG) is higher than that of HA. In an attempt to increase the bioactivity of Ha-coated Ti6Al4V and enhance the bonding strength between coating and substrate, in the present study, HA/BG composites are applied onto Ti6Al4V using a plasma spraying technique. Microstructure and phase changes of the composite coating after plasma spraying are studied. The coating-substrate bonding strength is evaluated using an Instron, following the ASTM C633 method. Results indicate that the average bonding strengths of BG, HA/BG and HA coatings are 33.0±4.3, 39.1±5.0, and 52.0±11.7 MPa, respectively. Open pores with sizes up to 50 μm are found in both BG and HA/BG coatings, which are probably advantageous in including mechanical interlocking with the surrounding bone structure, once implanted. These HA/BG composites could provide a coating system with sufficient bonding strength, higher bioactivity, and a significant reduction in cost in raw materials. The future of this HA/BG composite coating system seems pretty bright.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Conventional and high resolution transmission electron microscopy performed in this study provides some detailed microstructural information of a polyacrylonitrile (PAN) fibremesophase pitch matrix carbon-carbon composite which has not been published in open literature. The PAN fibre in this composite possesses a turbostratic structure throughout the fibre. The structure of the mesophase pitch matrix is graphitic and anisotropic. Near-fibre matrix crystallites are aligned roughly parallel to the fibre surface, exhibiting a flow-type morphology. The fibre-matrix interface in this composite is microfissured. Numerous microcracks exist both within the matrix and along partially bonded interfaces. The irregularly shaped interfacial microcracks readily expose the fibre surface topography. Microcracks within the matrix are formed between, and parallel to, the basal planes of the graphitic platelets. Such submicron-sized matrix cracks appear smaller and denser near the fibre-matrix interface.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Conventional and high resolution transmission electron microscopy performed in this study provides some detailed microstructural information of a polyacrylonitrile (PAN) fibremesophase pitch matrix carbon-carbon composite which has not been published in open literature. The PAN fibre in this composite possesses a turbostratic structure throughout the fibre. The structure of the mesophase pitch matrix is graphitic and anisotropic. Near-fibre matrix crystallites are aligned roughly parallel to the fibre surface, exhibiting a flow-type morphology. The fibre-matrix interface in this composite is microfissured. Numerous microcracks exist both within the matrix and along partially bonded interfaces. The irregularly shaped interfacial microcracks readily expose the fibre surface topography. Microcracks within the matrix are formed between, and parallel to, the basal planes of the graphitic platelets. Such submicron-sized matrix cracks appear smaller and denser near the fibre-matrix interface.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract The effect of load on the tribological behaviour of three different two-dimensional carbon-carbon composites, including polyacrylonitrile (PAN) fibre-pitch matrix, PAN fibre-chemical vapour infiltrated (CVI) matrix, and pitch fibre-resin/CVI hybrid matrix composites has been compared. Results indicated that friction and wear rate variations with slide distance depended on load and the type of composite. The worn surface morphology was categorized into three types (I, II and III). The friction coefficient, wear rate and temperature all increased sharply when the transition from type I to type II occurred. When the powdery type II debris was compacted to form the lubricative type III debris, the friction coefficient and wear rate declined, although never approached their initial type I levels. For all composites, a higher load can accelerate the transition from type I to type II, but impedes the transition from type II to type III. Under 2.4 MPa, the type II morphology was never observed to transform into type III morphology in this study.

Electronic Resource

1573-4811

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Two types of high-modulus short-carbon-fibre-reinforced commercially pure aluminium-matrix composites were fabricated in-house using a home-made squeeze caster. The type-I composites were fabricated from short-fibre preforms in which fibres exist as dispersed bundles. The type-II composites were fabricated from preforms in which individual fibres were uniformly dispersed. The detailed processes are described in the text. A three-point-bending strength of higher than 200 M Pa was obtained for the type-1 composite with 17 vol% of fibre. When more fibre was incorporated, both the strength and the ductility decreased due to inadequate infiltration. However, a bending strength of greater than 240 MPa was recorded on a hot-rolled type-I composite with a fibre content as high as 28 vol%. This significant improvement in the mechanical properties is explained by a hot-rolling-inducedvoid-healing effect. The type-II composites, with lower fibre volume fractions than those of the type-I due to their different preforms, exhibited bending strengths up to 166 MPa. Scanning electron microscopy fractography shows that the two types of composites fracture in distinctive manners. Transmission electron microscopy results featured thermal-stress-induced dislocations at carbon-aluminium interfaces as well as submicrometre-sized aluminium carbide, the reaction product, which nucleated from the interface and grew into the matrix interior.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract The process and wear behavior of monolithic SiC and 10 vol. % short carbon fiber-SiC matrix (C-SiC) composite have been studied. The results indicate that, among ethyl alcohol, acetone, n-hexane and n-octyl alcohol, n-octyl alcohol was the most effective dispersing agent in dispersing both SiC powder and short carbon fiber. Among AlN, Al2O3, B4C, graphite, AlN/B4C, AlN/graphite, B4C/graphite and Al2O3/B4C, the most effective sintering aid for the fabrication of SiC and C-SiC composite was a mixture of 2 wt% AlN and 0.5 wt% graphite. The monolithic SiC hot-pressed at 2100°C exhibited higher density but lower flexural strength than those hot-pressed at 2000°C due to a grain growth effect. For the C-SiC composite, both density and strength of the composite hot-pressed at 2100°C were generally higher than those hot-pressed at 2000°C. The density and strength of C-SiC composite were lower than those of monolithic SiC under the same hot pressing conditions due to a higher porosity level in the composite. When monolithic SiC slid against C-SiC composite, the weight losses of SiC and the composite were each less than that of self-mated SiC or self-mated C-SiC. In the self-mated SiC tribosystem, a mechanically stable film could not be established, resulting in an essentially constant wear rate. When sliding against C-SiC, a thin, smooth and adherent debris film was quickly formed on the SiC surface, resulting in a lower wear.

Electronic Resource