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Xiao-Hong Zhang

Publications and source records attributed to Xiao-Hong Zhang.

At least 19 recordsLinked to original sources
PubMed2007

Fluorescence turn on of coumarin derivatives by metal cations: a new signaling mechanism based on C=N isomerization.

[reaction: see text] A new sensing mechanism based on C=N isomerization, which shows a very significant fluorescence enhancement to the metal cations in a simple and efficient way, is demonstrated. A coumarin derivative (L) containing a C=N group was designed as an example for illustration. The free ligand L is almost nonfluorescent due to the isomerization of C=N double bond in the excited state. However, the solution of ligand shows about a 200-fold increase of fluorescence quantum yield (about 30%) upon addition of Zn(ClO4)2.

Journal Article↗
PubMed2006

Asymmetric dimethylarginine reduced erythrocyte deformability in streptozotocin-induced diabetic rats.

To investigate the effect of asymmetric dimethylarginine on erythrocyte deformability in streptozotocin-induced diabetic rats, a single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg) in male Sprague-Dawley rats was carried out to induce diabetes and normal erythrocytes were incubated with asymmetric dimethylarginine or aortic rings from diabetic rats in the presence of L-arginine or vitamin E. We found that erythrocyte deformability was significantly decreased in diabetic rats. The levels of asymmetric dimethylarginine in plasma and erythrocytes of diabetic rats were elevated significantly from 2-week diabetic duration to 8-week diabetic duration. Nitric oxide in erythrocytes was decreased at 8-week diabetic duration while plasma nitric oxide remained unchanged all along. The content of malondialdehyde in erythrocytes of diabetic rats was increased. After incubation of erythrocytes with asymmetric dimethylarginine (10(-6) M) for 30 min, erythrocyte deformability and nitric oxide level in erythrocytes were decreased markedly. Reactive oxygen species and malondialdehyde production in erythrocytes were promoted by asymmetric dimethylarginine. Both L-arginine and vitamin E reversed the effects of asymmetric dimethylarginine. After incubation of erythrocytes with aortic rings from diabetic rats, erythrocyte deformability was decreased, which was attenuated by L-arginine. These results indicated that reduction of erythrocyte deformability in diabetic rats was associated with promoted oxidant stress as well as impaired nitric oxide synthesis by elevation of asymmetric dimethylarginine.

Animals↗
PubMed2006

Probucol decreases asymmetrical dimethylarginine level by alternation of protein arginine methyltransferase I and dimethylarginine dimethylaminohydrolase activity.

HYPOTHESIS: Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor (NOS), may play an important role in endothelium dysfunction. Probucol, a potent antioxidant drug, may improve endothelium function via reduction of NOS inhibitor level. The present study examined whether the decreased level of ADMA by probucol is related to enhancement of protein arginine methyltransferase I (PRMT I) expression and reduction of dimethylarginine dimethylaminohydrolase (DDAH) activity. METHODS: Endothelial cells were cultured and used for all these studies. ADMA concentration and DDAH activity were determined by HPLC. Expression of PRMT I and eNOS were characterized by western blot. RESULTS: Pretreatment with oxidized-low density lipoprotein (ox-LDL) (10, 30 or 100 microg/ml) or lysophosphatidylcholine (LPC) (1.0, 2.5 or 5.0 microg/ml) for 12, 24 or 48 h markedly increased the activity of lactate dehydrogenase (LDH) in cultured endothelial cell. Incubation ofendothelial cells with ox-LDL (100 microg/ml) or LPC (5.0 microg/ml) for 48 h significantly increased the expression of PRMT I, and levels of MDA and ADMA, and decreased the concentration of nitrite/nitrate, the expression of eNOS and the activity of DDAH. Probucol significantly decreased the level of ADMA, concomitantly with reduction of PRMT I expression and elevation of DDAH activity and up-regulation of eNOS expression. CONCLUSION: In summary, the present results suggest that the protective effect of probucol on endothelium is related to reduction of ADMA concentration by inhibition of PRMT I expression and enhancement of DDAH activity.

Amidohydrolases↗
PubMed2006

[Effect of extracted liquid from qianlietongyu on the proliferation and apoptosis on prostatic smooth muscle cells in vitro].

OBJECTIVE: To explore the effect of extracted liquid from Qianlietongyu on the proliferation or apoptosis on prostatic smooth muscle cells in vitro. METHODS: After extracted liquid from Qianlietongyu treated the cultured prostatic smooth muscle cells, the anti proliferative and apoptotic indices were assessed by MTT assy and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) respectively. RESULTS: There was a significant dose-effect relationship between the concentration of extracted liquid from Qianlietongyu and the antiproliferative index on prostatic smooth muscle cells in vitro (P < 0.01), but there was no markedly difference in the apoptosis index between the group of extracted liquid from Qianlietongyu and control group ( P > 0.05). CONCLUSION: Extracted liquid from Qianlietongyu may show significant antiproliferative effect on prostatic smooth muscle cells in vitro, without inducing apoptosis.

Apoptosis↗
PubMed2006

[Dynamic fugacity model for describing the fate of persistent organic pollutants in the river].

Dynamic model depending on temperature with fugacity approach is formulated which describes the fate of Persistent Organic Pollutants (POPs) in a river. The fugacity capacity, the degradation rate and transfer coefficients of pollutants are depending on temperature in the model. The model is illustrated by calculating the fate of gamma-HCH in Liao River. The results show that from 273K to 298K, the fugacity capacities in air, water and sediment of gamma-HCH are respectively reduced in 8.4%, 89.7% and 89.7%. However, in the same range of temperature, the degradation rate coefficients in air, water and sediment, and volatilization and diffusion rate coefficients of gamma-HCH are increased in 0.69, 22.0, 4.5, 7.9 and 1.6 times, respectively. The calculated value agree well with the field observed value in the order of magnitude, which shows that the model is appropriate for simulating the fate of POPs in a long time.

Environmental Monitoring↗
PubMed2006

[Polymorphisms of eleven Y-chromosome STR loci and forensic application in Yunnan Han population].

OBJECTIVE: To abtain the genetic polymorphisms data of eleven Y-chromosome STR loci in Yunnan Han population, and to evaluate its forensic application values, which will provide the base data for forensic application. METHODS: DYS391, DYS389 I, DYS439, DYS389 II, DYS438, DYS437, DYS19, DYS392, DYS393, DYS390 and DYS385a/b loci were amplified by using Powerplex Y PCR amplification Kit and were analyzed by 310 genetic analyzer. 201 unrelated male individuals of Han population in Yunnan were investigated to determine the distributions of allele frequencies and haplotypes. RESULTS: 3, 5, 6, 8, 5, 4, 5, 8, 4, 7 alleles were found across the Y-STR loci except DYS38556 haplotypes were found across DYS385a/b locus. The minimum GD value was 0.4273 (DYS438), and the maximum was 0.9747 (DYS385a/b). 175 haplotypes were found, of which 154 were unique, 16 were found in 2 individuals, 5 were found in 3 individuals, and the observed haplotypes diversity value was 0.9984. CONCLUSION: The 11 Y-STR loci are highly polymorphic and are suitable for forensic personal identification and paternity testing in Yunnan Han population.

Alleles↗
PubMed2006

[Effect of different post-weaning dietary compositions on body fat content and hormone-sensitive lipase gene expression in rats fed with high-fat diet].

OBJECTIVE: To study the effects of different postweaning dietary compositions on body fat content and hormone-sensitive lipase (HSL) gene expression in rats fed a high-fat diet. METHODS: Male Wistar rats weaned on 24 days were randomly divided into A, B, C, D groups and were fed on high carbohydrate, high protein, high unsaturated fatty acid and high saturated fatty acid diet respectively. After 3 weeks, all rats were assigned to basic diet for two weeks, then rats from A group were randomly divided into A1 and A2 subgroups. A1 subgroup was fed on basic diet continuously. A2 subgroup and B, C and D groups were assigned to high-fat diet for six weeks. Eight rats from each group were sacrificed at the end of different treatments to detect body weight, body fat content and blood glucose level. RT-PCR was used to determine the gene expression of hormone-sensitive lipase in white adipose tissue. RESULTS: Body weight, body fat content and blood glucose level in C group were significantly lower than those in A2 subgroup on 11 weeks (P < 0.05). The body weight, body fat content in B2 group were significantly lower than those in A2 subgroup (P < 0.05), but blood glucose level was higher than A2 subgroup on 11 weeks (P > 0.05). The body weight in D group was significantly lower than that in A2 subgroup (P < 0.05), but body fat content and blood glucose level were not significantly lower than A2 subgroup on 11 weeks (P > 0.05). The expression of HSL in B2 and C group was higher on 9 weeks and 11 weeks respectively. The HSL mRNA levels in all groups on 3 weeks were similar to that on 11 weeks. CONCLUSION: Feeding on high unsaturated-fatty acid diet after weaning may significantly reduce the body weight, body fat content, improve the abnormal blood glucose level in rats induced by high-fat diet. It was suggested that the high unsaturated-fatty acid diet can be reasonable for weaned rats and gene expression regulation may be involved in programming later obesity by early nutrition.

Adipose Tissue↗
PubMed2005

Lysophosphatidylcholine-induced elevation of asymmetric dimethylarginine level by the NADPH oxidase pathway in endothelial cells.

Recent studies suggested that endothelium is a main source of reactive oxygen species (ROS) and the major source was via NADPH oxidase pathway. Various stimuli including lysophosphatidylcholine (LPC), a major component of oxidized low-density lipoprotein (ox-LDL), can enhance the activity of NADPH oxidase and lead to a marked ROS generation. Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) synthase (NOS) inhibitor, which is synthesized by protein arginine methyltransferase I (PRMT I) and degraded by dimethylarginine dimethylaminohydrolase (DDAH) in endothelial cells. Much evidence showed that ADMA was closely related to endothelial dysfunction. Our previous study showed that LPC elevated ADMA level in endothelial cells via increasing oxidative stress, but the precise cellular mechanism is not defined yet. The present study was to explore the mechanism of NADPH oxidase in LPC-induced elevation of ADMA. In LPC-treated endothelial cells, the ROS production, cell viability, ADMA and NO levels, the activity of DDAH and expression of PRMT I were detected. Treatment with LPC (10 microg/ml) for 24 h markedly increased intracellular ROS production, the expression of PRMT I, level of ADMA, decreased the concentration of NO and the activity of DDAH. These effects were attenuated by diphenyliodonium, the NADPH oxidase inhibitor. In summary, the present results suggested that LPC-induced elevation of ADMA was due to reduction of DDAH activity and the up-regulation of PRMT expression by stimulation of ROS production via NADPH oxidase pathway.

Amidohydrolases↗
PubMed2005

Electro-optic polymer waveguide grating with fast tuning capability.

A novel fast tunable electro-optic (EO) polymer waveguide grating is proposed and designed. Its resonant wavelength can be linearly tuned via the first-order EO effect with a high sensitivity of 6.1 pm/V. We find that the spectrum characteristics of EO polymer waveguide gratings depend strongly on many grating parameters, such as refractive-index modulation, modulation function, grating period, and period number. Material selection, fabrication technology, EO tuning ability, and polarization dependence of EO polymer waveguide gratings are also discussed. Such a waveguide grating not only overcomes the disadvantages of fiber-optic gratings, such as slow wavelength tuning ability and large-scale integration inconvenience, but also has many advantages, such as high resonant-wavelength tuning sensitivity, the same fabrication technology used for semiconductors, and polarization independence.

Journal Article↗
PubMed2005

New fluorescent chemosensor based on exciplex signaling mechanism.

[reaction: see text]. A novel fluorescent chemosensor (compound 1) containing aminonaphthol, which selectively recognizes fluoride anion with high sensitivity, was synthesized. The fluorescence of compound 1 was quenched rapidly by fluoride ion, and a new peak at a longer wavelength emerged concurrently, which constituted the signature for fluoride detection. The mechanism of exciplex formation was proposed for the interesting observation.

Journal Article↗
PubMed2005

Direct evidence of molecular aggregation and degradation mechanism of organic light-emitting diodes under joule heating: an STM and photoluminescence study.

The Joule heating effect on electroluminescent efficiency is important in the degradation origin of organic light-emitting diodes (OLED). Scanning tunneling microscopy (STM) and photoluminescence (PL) measurements were performed on the guest molecule BT (1,4-bis(benzothiazole-vinyl) benzene), host molecule TPBI (2, 2',2' '-(1,3,5-phenylene)tris-[1-phenyl-1H-benzimidazole]), and their mixture deposited on an HOPG surface to study the OLED degradation mechanism due to thermal heating. At room temperature, BT and TPBI in the mixed layer show good compatibility and high PL intensity, but at higher temperatures, they show phase separation and aggregation into their own domains and a concomitant decrease in PL intensity. The PL intensity loss suggests ineffective energy transfer from TPBI to BT due to phase separation, which may cause OLED degradation. Scanning tunneling spectroscopy (STS) results show that the band gaps of TPBI and BT remain unchanged with the annealing temperature, suggesting that the heat-induced decay of OLED is related to the interfacial structural change rather than the respective molecular band gap. The results provide direct evidence showing how the molecular structures of the mixed layer vary and affect the PL intensity due to temperature.

Journal Article↗
PubMed2005

An effective fluorescent chemosensor for the detection of copper(II).

The fluorescent compound N-substituted 2,6-bis(benzimidazol-2-yl)pyidine (1) has been synthesized. The fluorescent characteristics of the compound 1 and 2,6-bis(benzimidazol-2-yl)pyidine (2) and the complexes formed between the two compounds and different metal ions have also been investigated. The results show that the compound 1 possesses a specific ability to form complex with Cu(2+) ion, but the compound 2 have not such a property. It is proposed that the specific recognition ability of compound 1 to Cu(2+) may be attributed to the cyclic configuration of this compound in polar solvent.

Cations, Divalent↗
PubMed2005

Large-scale fabrication and characterization of Cd-doped ZnO nanocantilever arrays.

We demonstrate bulk synthesis of highly crystalline Cd-doped ZnO nanocantilever arrays (CZNAs) using Cd and Zn powders at 600 degrees C, which is characterized via scanning electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy, selected area electron diffraction, and high resolution TEM. The results show that the as-prepared CZNAs have diameters of about 15-50 nm, and lengths up to 400 nm and the corresponding process of growth is suggested for conventional vapor solid mechanism.

Journal Article↗
PubMed2005

[Quantification of human ermap by using real-time FQ-PCR].

To develop a real-time FQ-PCR method for quantifying human ermap, a set of primers and a fluorescent probe were designed by primer express 2.0. pBluescriptSK(+) plasmid contained ermap cDNA was transcribed to generate calibration standards for quantification. A real time FQ-PCR method was established. The results showed that when the concentrations of DNA to be amplified were ranged from 1.725 x 10(7) to 1.725 x 10(10) cps/ml, there was a good correlation between template concentration and cycle threshold, and the correlation coefficient reached to -0.999376. In conclusion, real time FQ-PCR which is specific, sensitive and accurate can be used to further research on human ermap.

Blood Group Antigens↗