Biomedical subjects

Jian-Guo Zheng

Publications and source records attributed to Jian-Guo Zheng.

4 recordsLinked to original sources

PubMed2006

Ferromagnetic self-assembled quantum dots on semiconductor nanowires.

Ferromagnetic self-assembled alpha-MnAs quantum dots (QD) were grown epitaxially on metal catalyst-grown InAs nanowires (NW) by chemical vapor deposition. Magnetic force microscopy measurements demonstrated that the QDs are stable, single-domain ferromagnets with T(c) values of approximately 310 K. Single QD switching was demonstrated at fields as low as 60 Oe. The hybrid ferromagnetic/semiconductor QD/NW properties provide a promising basis for the development of nanowire spin-valves and magnetic memory devices.

Journal Article↗

PubMed2005

Role of SPECT/CT in diagnosis of hepatic hemangiomas.

AIM: To investigate the role of SPECT/CT in the diagnosis of hepatic hemangiomas whose anatomical positions are not ideal, situated adjacent to the heart, the inferior cava, hepatic vessels or abdominal aorta, etc. METHODS: The hepatic perfusion, blood pool, and fusion imaging were carried out using SPECT/CT in 54 patients, who were suspected for hepatic hemangiomas. When the anatomical positions were not ideal, the diagnosis was difficult by SPECT only. So the information of computed tomography (CT) was applied to help in diagnosing. The results were recorded as hemangiomas or not. RESULTS: Of the 54 patients, 31 patients were diagnosed as suffering from hepatic hemangiomas. The anatomical positions of eight patients' hepatic hemangiomas (25.81%) were not ideal. Among these lesions of the eight patients, three patients' hepatic lesions were located near to the abdominal aorta, one to the heart, and four to the inferior cava. In addition, six abnormal radioactivity accumulation regions, adjacent to the heart and inferior cava, with the help of CT, were confirmed to be the imaging of inferior cava other than hepatic hemangiomas. CONCLUSION: When the anatomical positions of hepatic hemangiomas are not good enough for diagnosis, the fusion imaging of SPECT/CT is a simple and efficient method for differential diagnosis.

Adult↗

PubMed2004

Antisense imaging of colon cancer-bearing nude mice with liposome-entrapped 99m-technetium-labeled antisense oligonucleotides of c-myc mRNA.

AIM: To investigate the feasibility for antisense imaging of the colon cancer with liposome-entrapped 99 m-technetium labeled antisense oligonucleotides as tracers. METHODS: Fifteen mer single-stranded aminolinked phosphorothioate antisense oligonucleotides of c-myc mRNA were labeled with 99mTc-pertechnetate, then purified and finally entrapped with liposomes to form the labeling compounds, liposome-entrapped 99mTc-labeled antisense oligonucleotides. The LS-174-T cells (colon of adenocarcinoma cell line) were incubated with the labeling compounds to test the uptake rates of LS-174-T cells. Later on, a model of 30 tumor bearing nude mice was constructed by inoculating with 5 x 10(6) of LS-174-T cells at right flank of each nude mouse. About 10 d later, the model were administered by intravenous injection of the liposome-entrapped 99mTc-labeled antisense oligonucleotides. Then some of the tumour bearing nude mice were sacrificed at 0.5, 1, 2, and 4 h after intravenous injection, and proper quantity of liver, spleen, tumor, etc. was obtained. The tissues were counted in a gamma counter, and after correction for decay and background activity, expressed as a percentage of the injected dose. The others whose anterior and posterior whole-body scans were obtained at 1, 1.5, 2, 4, 6 and 24 h with a dual-head bodyscan camera equipped with parallel-hole low-energy collimaters. The ratios of radioactive counts in tumor to that in contralateral equivalent region of abdomen were calculated. RESULTS: The uptake rates of LS-174-T cells for liposome-entrapped 99mTc-labeled antisense oligonucleotides increased as time prolonged and reach the peak (17.77 +/- 2.41%) at 7 h. The biodistributions showed that the radioactivity in the tumor (13.46 +/- 0.20%) of injected dose was the highest at 2 h of intravenous injection of liposome-entrapped 99mTc-labeled antisense oligonucleotides, and then decreased sharply to 4.58 +/- 0.45% at 4 h. The tumor was shown clearly in the whole-body scan at 2 h of intravenous injection. The ratios, radioactive counts in tumor to that in contralateral equivalent region of abdomen (1.7332 +/- 0.2537), was the highest one at 2 h after intravenous injection of liposome-entrapped 99mTc-labeled antisense oligonucleotides. CONCLUSION: The liposome-entrapped 99mTc-labeled antisense oligonucleotides deserve being developed into radiopharmaceutics for the colon cancer imaging.

Animals↗

PubMed2004

Transparent conducting oxides: texture and microstructure effects on charge carrier mobility in MOCVD-derived CdO thin films grown with a thermally stable, low-melting precursor.

A series of low-melting, thermally stable cadmium metal-organic chemical vapor deposition (MOCVD) precursors have been synthesized, structurally and spectroscopically characterized, and implemented in growth of highly conductive and transparent CdO thin films. One member of the series, bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)(N,N-diethyl-N',N'-dimethyl-ethylenediamine)cadmium(II), Cd(hfa)(2)()(N,N-DE-N',N'-DMEDA), represents a particularly significant improvement over previously available Cd precursors, owing to the low melting point and robust thermal stability. High-quality CdO films were grown by MOCVD on glass and single-crystal MgO(100) between 300 and 412 degrees C. Film growth parameters and substrate surface have large effects on microstructure and electron carrier transport properties. Enhanced mobilities observed for highly biaxially textured films grown on MgO(100) vs glass are attributed, on the basis of DC charge transport and microstructure analysis, to a reduction in neutral impurity scattering and/or to a more densely packed grain microstructure. Although single-grained films grown on MgO(100) exhibit greater mobilities than analogues with discrete approximately 100 nm grains and similar texture, this effect is attributed, on the basis of charge transport and Hall effect measurements as well as optical reflectivity analysis, to differences in carrier concentration rather than to reduced grain boundary scattering. Unprecedented conductivities and mobilities as high as 11,000 S/cm and 307 cm(2)/V.s, respectively, are obtained for epitaxial single-grained films (X-ray diffraction parameters: fwhm(omega) = 0.30 degrees, fwhm(phi) = 0.27 degrees ) grown in situ on MgO(100) at a relatively low temperature (400 degrees C).

Journal Article↗