Biomedical subjects

Xiaowei Zhao

Publications and source records attributed to Xiaowei Zhao.

8 recordsLinked to original sources

PubMed2006

Structural, magnetic, and magnetoresistive properties of electrodeposited Ni5Zn21 alloy nanowires.

Ni5Zn21 alloy nanowires were fabricated through template-assisted electrochemical deposition method. The morphology and microstructures of as-deposited nanowires were determined by field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), electron diffraction (ED), and electron probe microanalysis (EPMA). The accurate composition was measured via induced coupling plasma atomic emission spectroscopy. SEM results show that Ni5Zn21 nanowires are deposited in most of the nanopores of the template, and they are continuous and dense throughout the whole length. The XRD result demonstrates that the nanowires are mainly composed of a cubic gamma phase Ni5Zn21 alloy, but there also exists a trace of Zn-rich eta phase. HRTEM and ED reveal that the alloy nanowires are polycrystalline with the crystallite size of several tens of nanometers. EPMA of a single nanowire illustrates that there exist Ni-rich microzones in as-deposited nanowires. Subsequent magnetic measurements of the array also confirmed the existence of them. In addition, it can be further inferred that the shape of Ni-rich microzones is probably barlike or disklike, from the anisotropy of zero field cooling/field cooling (ZFC/FC) curves as well as the vortex magnetization behavior of the Ni5Zn21 nanowire array. The low-temperature magnetoresistance of the Ni5Zn21 nanowire array was also measured. Giant magnetoresistance instead of anisotropic magnetoresistance is suggested to be responsible for contributing to the magnetoresistance.

Journal Article↗

PubMed2006

Growth mechanism, photoluminescence, and field-emission properties of ZnO nanoneedle arrays.

ZnO nanoneedle arrays have been grown on a large scale with a chemical vapor deposition method at 680 degrees C. Zn powder and O(2) gas are employed as source materials, and catalyst-free Si plates are used as substrates. Energy-dispersive X-ray and X-ray diffraction analyses show that the nanoneedles are almost pure ZnO and preferentially aligned in the c-axis direction of the wurtzite structure. The growth mechanism of ZnO nanoneedle arrays is discussed with the thermodynamic theory and concluded to be the result of the co-effect of the surface tension and diffusion. Photoluminescence spectrum of the as-grown products shows a strong emission band centering at about 484 nm, which originates from oxygen vacancies. Field-emission examination exhibits that the ZnO nanoneedle arrays have a turn-on voltage at about 5.3 V/microm.

Journal Article↗

PubMed2006

Human fibrinogen adsorption onto single-walled carbon nanotube films.

The adsorption behavior of human fibrinogen (Hfg) on single-walled carbon nanotube (SWNT) films was investigated using scanning electron microscopy (SEM) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. It was shown in the SEM images that fibrinogen was adsorbed strongly on the surface of SWNT when the samples were incubated in the Hfg solutions for 10 min. The dependence of adsorption on the concentration of fibrinogen was also investigated and it was found that adsorption increased with increasing concentration. In order to further explore the adsorption of fibrinogen on SWNT surface, NEXAFS spectra were obtained at the N K-edge and the C K-edge. The results confirmed the conclusion regarding the dependence of adsorption on fibrinogen concentration. It is demonstrated that, due to its high sensitivity to the surface elements, NEXAFS spectroscopy is a powerful tool to investigate the adsorption of fibrinogen on SWNT films.

Adsorption↗

PubMed2006

Language history questionnaire: A web-based interface for bilingual research.

A Web-based interface has been developed to facilitate researchers in collecting language history information online. Most researchers use their own versions of language history questionnaires for specific studies in second language acquisition. Although these versions of questionnaires all differ from one another in some respects, there is a significant amount of overlap between them. Here we identify the crucial dimensions that most investigators consider important to include in such a questionnaire. We have examined the most commonly asked questions in 41 published questionnaires, and on the basis of our analyses we propose a general L2 language history questionnaire. Subjects can enter some or all of the information on the Web, and the results are automatically generated as an RTF output file on the user's desktop.

Documentation↗

PubMed2006

[Thumb reconstruction with skin and soft tissue expansion].

OBJECTIVE: To evaluate a new reconstruction method for grades V and VI defect with flap by skin soft tissue expansion technique. METHODS: From May 1998 to September 2003, 8 cases of serious thumb defect were treated, including 6 males and 2 females, aging 18-27 years. The defect was caused by crush injury of machine in 6 cases and hot crush injury in 2 cases (5 cases of grade V and 3 cases of grade VI). The expander was placed under the tenor skin and soft-tissue. And then normal saline was infused to expand the skin and soft tissue gradually till it was available for thumb reconstruction. Iliac autograft was fixed to residual thumb stump and covered with flap produce by expanded skin and soft-tissue. Postoperative rehabilitation was carried out. RESULTS: All reconstructed thumbs were alive. After 3-24 months follow-up, all reconstructed thumbs were with good sensation, appearance and durable. Two-point discrimination was less than 5 mm. The functions of opposition, extend, abduction and endoduction were better in grade V thumb defect than in grade VI thumb defect. Bone union was achieved within 3 to 4 months. CONCLUSION: It is a convenient-to-operate and reliable method for thumb reconstruction. It is an alternative new reconstruction method for grades V and VI, thumb defect.

Adolescent↗

PubMed2005

Low-temperature growth and photoluminescence property of ZnS nanoribbons.

At a low temperature of 450 degrees C, ZnS nanoribbons have been synthesized on Si and KCl substrates by a simple chemical vapor deposition (CVD) method with a two-temperature-zone furnace. Zinc and sulfur powders are used as sources in the different temperature zones. X-ray diffraction (XRD), selected area electron diffraction (SEAD), and transmission electron microscopy (TEM) analysis show that the ZnS nanoribbons are the wurtzite structure, and there are two types-single-crystal and bicrystal nanoribbons. Photoluminescence (PL) spectrum shows that the spectrum mainly includes two parts: a purple emission band centering at about 390 nm and a blue emission band centering at about 445 nm with a weak green shoulder around 510 nm.

Journal Article↗

PubMed2005

Synthesis of long indium nitride nanowires with uniform diameters in large quantities.

Large quantities of indium nitride (InN) nanowires are synthesized by the in situ nitriding of indium oxide (In(2)O(3)) powders in an ammonia (NH(3)) flux. Tens of milligrams of nanowires are obtained in one batch. Every 100 mg of In(2)O(3) starting powder can produce up to 65 mg of InN nanowires under the optimized conditions. The synthesized nanowires grow along the [001] direction with excellent crystallinity. They are of high purity and are 30-50 microm in length with an almost uniform diameter of about 100 nm. Photoluminescence measurements of the nanowires exhibit a strong peak at 707 nm. An optical bandgap of about 1.7 eV is estimated based on the absorption spectrum. The experimental results also demonstrate that the approach of nitriding In(2)O(3) powders in situ is feasible for the synthesis of high-purity InN nanowires in large quantities, with good reproducibility and without catalyst materials. The synthesis of InN nanowires in large quantities would be of benefit to the further study and understanding of their intrinsic properties, as well as being advantageous for their potential application in nanodevices.

Indium↗

PubMed2004

Advances in diagnosis and treatment of hepatic steatosis.

Although many breakthroughs have been made in biomedicine, however, a satisfactory treatment is still lacking. On the other hand, treatment with TCM drugs has been proved satisfactory through there is no unified criterion on type differentiation in diagnostics. Hepatic steatosis due to alcoholic hepatitis could be effectively treated with the therapeutic methods of soothing the liver, promoting blood circulation and resolving phlegm. Generally speaking, hepatic steatosis can be treated with the principles of 1) soothing the liver, strengthening the spleen and resolving phlegm; 2) tonifying the liver and kidney, resolving phlegm and dispelling stasis; 3) soothing the liver and promoting blood circulation, strengthening the spleen and excreting dampness; 4) soothing the depressed liver to regulate the circulation of qi, softening hardness and promoting blood circulation; and 5) strengthening the spleen and excreting dampness and soothing the depressed liver to regulate the circulation of qi.

Animals↗