251
|
Shan T, Ren Y, Wang Y. Sirtuin 1 affects the transcriptional expression of adipose triglyceride lipase in porcine adipocytes. J Anim Sci 2013; 91:1247-54. [PMID: 23296834 DOI: 10.2527/jas.2011-5030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To investigate whether sirtuin 1 (Sirt1) could affect the transcriptional expression of the adipose triglyceride lipase (ATGL) gene, we treated porcine adipocytes with the general Sirt1 activator resveratrol (RES) with the Sirt1 inhibitor nicotinamide (NAM) or a knockdown of Sirt1 by Sirt1-specific small interfering RNA (siRNA). The RES (50 μM) activated Sirt1 gene expression and increased ATGL gene expression and glycerol release (P < 0.01). The Sirt1 inhibitor NAM or knockdown with Sirt1 siRNA further proved that the ATGL mRNA abundances were decreased (P < 0.05) after inhibition with Sirt1 in adipocytes. Furthermore, we found the opposite Sirt1 regulation pattern for PPARγ to that of ATGL in adipocytes. In summary, Sirt1 regulates the transcriptional expression of ATGL in adipocytes, and PPARγ appears to have an important role in this process. These results add to our understanding of the role of Sirt1 in adipose mobilization.
Collapse
|
252
|
Petkov V, Ren Y, Kabekkodu S, Murphy D. Atomic pair distribution functions analysis of disordered low-Z materials. Phys Chem Chem Phys 2013; 15:8544-54. [DOI: 10.1039/c2cp43378h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
253
|
Wang J, Ren Y, Zhu Y, Chen JW, Zhu MM, Xu YJ, Tan ZM. Effect of penehyclidine hydrochloride on the incidence of intra-operative awareness in Chinese patients undergoing breast cancer surgery during general anaesthesia. Anaesthesia 2012; 68:136-41. [DOI: 10.1111/anae.12092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2012] [Indexed: 11/30/2022]
|
254
|
Lu H, Ni K, Wang C, Black KC, Wei D, Ren Y, Messersmith PB. A novel technique for in situ aggregation of Gluconobacter oxydans using bio-adhesive magnetic nanoparticles. Biotechnol Bioeng 2012; 109:2970-7. [PMID: 22729662 PMCID: PMC3477288 DOI: 10.1002/bit.24582] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 05/02/2012] [Accepted: 06/11/2012] [Indexed: 01/22/2023]
Abstract
Here, we present a novel technique to immobilize magnetic particles onto whole Gluconobacter oxydans in situ via a synthetic adhesive biomimetic material inspired by the protein glues of marine mussels. Our approach involves simple coating of a cell adherent polydopamine film onto magnetic nanoparticles, followed by conjugation of the polydopamine-coated nanoparticles to G. oxydans which resulted in cell aggregation. After optimization, 21.3 mg (wet cell weight) G. oxydans per milligram of nanoparticle was aggregated and separated with a magnet. Importantly, the G. oxydan aggregates showed high specific activity and good reusability. The facile approach offers the potential advantages of low cost, easy cell separation, low diffusion resistance, and high efficiency. Furthermore, the approach is a convenient platform technique for magnetization of cells in situ by direct mixing of nanoparticles with a cell suspension.
Collapse
|
255
|
Zheng X, Reddy R, Schipper M, Ren Y, Chang A, Lin J, Orringer M, Kong F. Comparisons of Local Control and Survival of Stereotactic Body Radiation Therapy Versus Surgery for Stage I Non-small Cell Lung Cancer: A Meta-Analysis. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
256
|
Ono M, Bell M, Kaita R, Kugel H, Ahn JW, Allain J, Battaglia D, Bell R, Canik J, Ding S, Gerhardt S, Gray T, Guttenfelder W, Hosea J, Jaworski M, Kallman J, Kaye S, LeBlanc B, Maingi R, Mansfield D, McLean A, Menard J, Muller D, Nelson B, Nygren R, Paul S, Raman R, Ren Y, Ryan P, Sabbagh S, Scotti F, Skinner C, Soukhanovskii V, Surla V, Taylor C, Timberlake J, Yuh H, Zakharov L. Recent progress of NSTX lithium program and opportunities for magnetic fusion research. FUSION ENGINEERING AND DESIGN 2012. [DOI: 10.1016/j.fusengdes.2011.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
257
|
Li G, Hong Q, Ren Y, Lillehoj HS, He C, Ren X. Development of FPV140 antigen-specific ELISA differentiating fowlpox virus isolates from all other viral pathogens of avian origin. Poult Sci 2012; 91:2507-11. [PMID: 22991535 DOI: 10.3382/ps.2012-02297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The FPV140 gene encodes an envelope protein of fowlpox virus (FPV). In this study, the FPV140 gene of FPV Chinese isolate HH2008 was cloned and the comparison of its sequence with other FPV isolates showed it to be highly conserved across all FPV isolates. A recombinant plasmid pET-FPV140 carrying FPV140 gene was constructed and transformed into Escherichia coli. The optimal expression condition for the FPV140 gene was developed and purified FPV140 recombinant protein was used to produce rabbit polyclonal antibody. An indirect ELISA using this anti-FPV140 polyclonal antibody was capable of distinguishing avian FPV isolates from other common avian pathogens such as mycoplasma gallisepticum, infectious laryngotracheitis virus, avian influenza virus, infectious bursal disease virus, and avian infectious bronchitis virus. This ELISA will serve as a useful diagnostic tool for the detection of FPV in clinical samples.
Collapse
|
258
|
Yang L, Guo GQ, Chen LY, Huang CL, Ge T, Chen D, Liaw PK, Saksl K, Ren Y, Zeng QS, LaQua B, Chen FG, Jiang JZ. Atomic-scale mechanisms of the glass-forming ability in metallic glasses. PHYSICAL REVIEW LETTERS 2012; 109:105502. [PMID: 23005298 DOI: 10.1103/physrevlett.109.105502] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 07/07/2012] [Indexed: 06/01/2023]
Abstract
The issue, composition dependence of glass-forming ability (GFA) in metallic glasses (MG), has been investigated by systematic experimental measurements coupled with theoretical calculations in Cu-Zr and Ni-Nb alloy systems. It is found that the atomic-level packing efficiency strongly relates to their GFA. The best GFA is located at the largest difference in the packing efficiency of the solute-centered clusters between the glassy and crystal alloys in both MG systems. This work provides an understanding of GFA from atomic level and will shed light on the development of new MGs with larger critical sizes.
Collapse
|
259
|
Chen T, Zhang X, Long Y, Yu H, Ran X, Gao Y, Lu H, Xie X, Chen X, Ren Y, Shi J, Tian H. The association of plasma free amino acids with liver enzymes in Type 2 diabetic patients. J Endocrinol Invest 2012; 35:772-5. [PMID: 22071500 DOI: 10.3275/8059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Elevated γ-glutamyl transpeptidase (GGT) and alanine aminotransferase (ALT) could predict the risk of Type 2 diabetes (T2D), but the reason for their elevation was unclear. GGT and ALT mediated the metabolism of many amino acids (AA). Up to now, it was not investigated whether abnormal AA concentration was associated with elevated liver enzymes. AIM This study was to investigate the status of AA in T2D and their relationship with liver enzymes. SUBJECTS AND METHODS A total of 132 T2D patients and 137 healthy controls were recruited. Plasma free AA were measured by high-performance liquid chromatography. The contribution of individual AA to liver enzymes was assessed by stepwise linear regression. RESULTS a) The levels of alanine, valine, leucine, isoleucine, phenylalanine, tyrosine, methionine, glutamate, and lysine were higher while the level of glycine was lower in T2D than in controls (all p<0.01). b) Glutamate contributed to GGT in T2D, and its contribution was even greater than that of waist circumference. Leucine, lysine, and glutamate contributed to ALT. CONCLUSION There were significant differences in plasma AA profile between T2D and controls. Abnormal AA might contribute to elevated liver enzymes. The interaction between AA, liver enzymes, and the risk of T2D should be further investigated by prospective studies.
Collapse
|
260
|
Ni K, Zhou X, Zhao L, Wang H, Ren Y, Wei D. Magnetic catechol-chitosan with bioinspired adhesive surface: preparation and immobilization of ω-transaminase. PLoS One 2012; 7:e41101. [PMID: 22815930 PMCID: PMC3398885 DOI: 10.1371/journal.pone.0041101] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 06/21/2012] [Indexed: 11/23/2022] Open
Abstract
The magnetic chitosan nanocomposites have been studied intensively and been used practically in various biomedical and biological applications including enzyme immobilization. However, the loading capacity and the remained activity of immobilized enzyme based on existing approaches are not satisfied. Simpler and more effective immobilization strategies are needed. Here we report a simple catechol modified protocol for preparing a novel catechol-chitosan (CCS)-iron oxide nanoparticles (IONPs) composites carrying adhesive moieties with strong surface affinity. The ω-transaminase (ω-TA) was immobilized onto this magnetic composite via nucleophilic reactions between catechol and ω-TA. Under optimal conditions, 87.5% of the available ω-TA was immobilized on the composite, yielding an enzyme loading capacity as high as 681.7 mg/g. Furthermore, the valuation of enzyme activity showed that ω-TA immobilized on CCS-IONPs displayed enhanced pH and thermal stability compared to free enzyme. Importantly, the immobilized ω-TA retained more than 50% of its initial activity after 15 repeated reaction cycles using magnetic separation and 61.5% of its initial activity after storage at 4°C in phosphate buffered saline (PBS) for 15 days. The results suggested that such adhesive magnetic composites may provide an improved platform technology for bio-macromolecules immobilized.
Collapse
|
261
|
Cui M, Hovenier JN, Ren Y, Polo A, Gao JR. Terahertz wavefronts measured using the Hartmann sensor principle. OPTICS EXPRESS 2012; 20:14380-14391. [PMID: 22714499 DOI: 10.1364/oe.20.014380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We demonstrate for the first time that the Hartmann wavefront sensor (HWS) principle can be applied for characterizing the wavefronts of terahertz (THz) electromagnetic radiation. The THz Hartmann wavefront sensor consists of a metallic plate with an array of holes and a two-dimensional scanable pyro-electric detector. The THz radiation with different wavefronts was generated by a far-infrared gas laser operated at 2.5 THz in combination with a number of objects that result in known wavefronts. To measure the wavefront, a beam passing through an array of holes generates intensity spots, for which the positions of the individual spot centroids are measured and compared with reference positions. The reconstructed wavefronts are in good agreement with the model expectations.
Collapse
|
262
|
Petkov V, Ren Y, Suchomel M. Molecular arrangement in water: random but not quite. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:155102. [PMID: 22418283 DOI: 10.1088/0953-8984/24/15/155102] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Water defines life on Earth from the cellular to the terrestrial level. Yet the molecular level arrangement in water is not well understood, posing problems in comprehending its very special chemical, physical and biological properties. Here we present high-resolution x-ray diffraction data for water clearly showing that its molecular arrangement exhibits specific correlations that are consistent with the presence of rings of H(2)O molecules linked together by hydrogen bonds into tetrahedral-like units from a continuous network. This level of molecular arrangement complexity is beyond what a simple 'two-state' model of water (Bernal and Fowler 1933 J. Chem. Phys.1 515-48) could explain. It may not be explained by the recently put forward 'chains-clusters of completely uncorrelated molecules' model (Wernet et al 2004 Science 304 995-9) either. Rather it indicates that water is homogeneous down to the molecular level where different water molecules form tetrahedral units of different perfection and/or participate in rings of different sizes, thus experiencing different local environments. The local diversity of this tetrahedral network coupled to the flexibility of the hydrogen bonds that hold it together may explain well the rich phase diagram of water and why it responds non-uniformly to external stimuli such as, for example, temperature and pressure.
Collapse
|
263
|
Duan L, Ren Y. Role of notch signaling in osteoimmunology--from the standpoint of osteoclast differentiation. Eur J Orthod 2012; 35:175-82. [DOI: 10.1093/ejo/cjs002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
264
|
Chen JH, Ren Y, Seow J, Liu T, Bang WS, Yuk HG. Intervention Technologies for Ensuring Microbiological Safety of Meat: Current and Future Trends. Compr Rev Food Sci Food Saf 2012. [DOI: 10.1111/j.1541-4337.2011.00177.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
265
|
Wiranto MG, Tutein Nolthenius HE, van der Meer WJ, Engelbrecht WP, Ren Y. [Validity and reliability of digital diagnostic measurements on digital three-dimensional dental models]. Ned Tijdschr Tandheelkd 2012; 119:78-83. [PMID: 22428274 DOI: 10.5177/ntvt.2012.02.11175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Digital three-dimensional dental models are widely used for orthodontic diagnosis. The aim of this clinical study was to assess the validity and reliability of digital diagnostic measurements on digital three-dimensional dental models. Two types of digital three-dimensional dental models and a plaster dental model were made of 10 volunteers. Digital measurements of the tooth width were compared with the physical measurements of the plaster models. None of the digital diagnostic measurements appeared to differ significantly from the physical measurements.
Collapse
|
266
|
Zhou Y, Li F, Tian X, Zhu L, Yang Y, Luo X, Ren Y, Pang H. 3.019 ASSOCIATION OF PARKINSON'S DISEASE WITH SIX SNPS LOCATED ON FOUR PARK S GENES IN NORTHERN HAN CHINESE POPULATION. Parkinsonism Relat Disord 2012. [DOI: 10.1016/s1353-8020(11)70755-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
267
|
Liu L, Luo XG, Ren Y, Ren ZX, He ZY. 1.017 LANGUAGE ABILITY AFFECTED AND RELATED TO MOTOR SKILLS IN PARKINSON'S DISEASE — A PRELIMINARY REPORT. Parkinsonism Relat Disord 2012. [DOI: 10.1016/s1353-8020(11)70131-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
268
|
Zhu L, Zhou Y, Li F, Yang Y, Luo X, Ren Y, Pang H. 3.030 LACK OF ASSOCIATION BETWEEN THREE SNPS ON PARK9, PARK15 AND BST1 GENES AND PARKINSON'S DISEASE IN NORTHERN HAN CHINESE POPULATION. Parkinsonism Relat Disord 2012. [DOI: 10.1016/s1353-8020(11)70766-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
269
|
Ren Y, Almagri AF, Fiksel G, Prager SC, Sarff JS, Terry PW. Experimental observation of anisotropic magnetic turbulence in a reversed field pinch plasma. PHYSICAL REVIEW LETTERS 2011; 107:195002. [PMID: 22181614 DOI: 10.1103/physrevlett.107.195002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Indexed: 05/31/2023]
Abstract
In this Letter we report an experimental study of fully developed anisotropic magnetic turbulence in a laboratory plasma. The turbulence has broad (narrow) spectral power in the perpendicular (parallel) direction to the local mean magnetic field extending beyond the ion cyclotron frequency. Its k[see symbol] spectrum is asymmetric in the ion and electron diamagnetic directions. The wave number scaling for the short wavelength fluctuations shows exponential falloff indicative of dissipation. A standing wave structure is found for the turbulence in the minor radial direction of the toroidal plasma.
Collapse
|
270
|
Fu S, Sun C, Tao X, Ren Y. Anti-inflammatory effects of active constituents extracted from Chinese medicinal herbs against Propionibacterium acnes. Nat Prod Res 2011; 26:1746-9. [PMID: 21999396 DOI: 10.1080/14786419.2011.608675] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-α) from keratinocyte play important roles in initiating the inflammatory process of acne. They are used as major elements to evaluate the anti-inflammatory activity of drugs. In this study, various active constituents extracted from Chinese medicinal herbs were tested for their anti-inflammatory effects against P. acnes using ELISA. Among the constituents, matrine, baicalin, ursolic acid, sodium danshensu, magnolol, honokiol, hesperidin and andrographolide significantly reduced IL-8 and TNF-α by human HaCaT keratinocyte cells pretreated with heat-killed P. acnes. Excepting hesperidin, these active constituents presented dose-dependent inhibitory effects. Our studies showed that all of them exhibited low cytotoxicity at 5 µg mL⁻¹ in tested cell lines, and even at 50 µg mL⁻¹, in the cases of matrine, baicalin, ursolic acid and sodium danshensu. Based on the obtained results, it can be suggested that these active constituents are potential acne-mitigating candidates for cosmetic applications.
Collapse
|
271
|
Wang P, Zhang F, Ren Y, Wang L. The function of TNF in unstable angina pectoris (UAP) and effect of fasudil to it. BRITISH HEART JOURNAL 2011. [DOI: 10.1136/heartjnl-2011-300867.684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
272
|
Ren Y, Zhang X, Li L, Wang W. Improved fixation technique reduces time consuming and increases fish efficiency. Fertil Steril 2011. [DOI: 10.1016/j.fertnstert.2011.07.865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
273
|
Zhu SS, Ren Y, Zhang M, Cao JQ, Yang Q, Li XY, Bai H, Jiang L, Jiang Q, He ZG, Chen Q. Wld(S) protects against peripheral neuropathy and retinopathy in an experimental model of diabetes in mice. Diabetologia 2011; 54:2440-50. [PMID: 21739347 DOI: 10.1007/s00125-011-2226-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Accepted: 05/31/2011] [Indexed: 10/18/2022]
Abstract
AIMS/HYPOTHESIS We aimed to evaluate the effect of the mutant Wld(S) (slow Wallerian degeneration; also known as Wld) gene in experimental diabetes on early experimental peripheral diabetic neuropathy and diabetic retinopathy. METHODS The experiments were performed in four groups of mice: wild-type (WT), streptozotocin (STZ)-induced diabetic WT, C57BL/Wld(S) and STZ-induced diabetic C57BL/Wld(S). In each group, intraperitoneal glucose and insulin tolerance tests were performed; blood glucose, glycated haemoglobin and serum insulin were monitored. These mice were also subjected to the following behavioural tests: grasping test, hot-plate test and von Frey aesthesiometer test. For some animals, sciatic-tibial motor nerve conduction velocity, tail sensory nerve conduction velocity and eye pattern electroretinogram were measured. At the end of the experiments, islets were isolated to detect glucose-stimulated insulin secretion, ATP content and extent of apoptosis. The NAD/NADH ratio in islets and retinas was evaluated. Surviving retinal ganglion cells were estimated by immunohistochemistry. RESULTS We found that the Wld(S) gene is expressed in islets and protects beta cells against multiple low doses of STZ by increasing the NAD/NADH ratio, maintaining the ATP concentration, and reducing apoptosis. Consistently, significantly higher insulin concentrations, lower blood glucose concentrations, and better glucose tolerance were observed in Wld(S) mice compared with WT mice after STZ treatment. Furthermore, Wld(S) alleviated abnormal sensory responses, nerve conduction, retina dysfunction and reduction of surviving retinal ganglion cells in STZ-induced diabetic models. CONCLUSIONS/INTERPRETATION We provide the first evidence that expression of the Wld(S) gene decreases beta cell destruction and preserves islet function in STZ-induced diabetes, thus revealing a novel protective strategy for diabetic models.
Collapse
|
274
|
Yang L, Tao J, Tang X, Wang Y, He X, Xu G, Ren Y, Tu Y. Prevalence and correlation of conventional and lupus-specific risk factors for cardiovascular disease in Chinese systemic lupus erythematosus patients. J Eur Acad Dermatol Venereol 2011; 26:95-101. [DOI: 10.1111/j.1468-3083.2011.04211.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
275
|
Ren Y, Chiam SY, Chim WK. Diameter dependence of the void formation in the oxidation of nickel nanowires. NANOTECHNOLOGY 2011; 22:235606. [PMID: 21483086 DOI: 10.1088/0957-4484/22/23/235606] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this work, we show how the vacancy diffusion length scale must be considered, in the context of the diameter of a nanowire, when utilizing the Kirkendall phenomenon in the fabrication of metal oxide nanotubes starting from metal nanowires. We find that the diameter of the nanowire relative to the diffusion length scale of the vacancy will affect greatly the type of voids that can be generated. By using a larger diameter nickel nanowire, we show that segmented heterojunction void formation can be avoided and that the resulting structure will serve as a precursory 'template' for subsequent oxidation processes at high temperatures. In doing so, we can prevent the formation of bamboo-like structures and obtain uniform nickel oxide nanotubes through direct oxidation that has proven to be difficult previously. The result from this work is also significant as the interplay of vacancy diffusion length and nanostructure dimension is important in the oxidation of other types of metal nanostructures, especially when void formation and the Kirkendall effect are involved.
Collapse
|