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Yong Shao

Publications and source records attributed to Yong Shao.

11 recordsLinked to original sources
PubMed2005

Electrochemical thinning of thicker gold film with qualified thickness for surface plasmon resonance sensing.

To meet the requirement of surface plasmon resonance (SPR) sensing, controlling the thickness of the gold film is very important. Here, we report an efficient and simple approach to prepare a SPR-active substrate when the thickness of the gold film is larger than the optimizing 50 nm and smaller than 100 nm. This method is based on anodic electrodissolution of gold in electrolyte containing chloride ions. Using this method, the thickness of gold films can be easily changed at a nanometer scale by controlling the number of potential scans and the concentrations of chloride ions in the electrolyte. At the same time, the influence of gold film thickness on the SPR signal is recorded by SPR in real time. To assess the change of the surface roughness and morphology of gold film through anodic electrodissolution, atomic force microscopy was used. The surface roughness of the same Au film before and after anodic electrodissolution is 1.179 and 2.767 nm, respectively. The change of the surface roughness of Au film brings out a slight angle shift of SPR. This indicates that surface electrodissolution of the gold does not affect the character of the original bulk film and this film can be used for SPR experiments. To confirm our expectation, a simple adsorption experiment of cytochrome c (Cyt c) on the gold film treated with anodic electrodissolution modified by 11-mercaptoundecanic acid was carried out. The angle shift of SPR confirmed the adsorption of Cyt c, and the cyclic voltammetry of Cyt c provided a complementary confirmation for the adsorption of Cyt c. These results show that this approach provides a good way to change the thicker gold film to an optimized thickness of SPR sensing. The great advantage brought by this approach is in that it can convert the waste gold films with greater thicknesses fabricated by the vacuum deposition method or other methods into useful materials as active SPR substrates.

Journal Article↗
PubMed2005

Conducting polymer polypyrrole supported bilayer lipid membranes.

Electrochemically synthesized conducting polymer polypyrrole (PPy) film on gold electrode surface was used as a novel support for bilayer lipid membranes (BLMs). Investigations by surface plasmon resonance (SPR) suggest that dimyristoyl-L-alpha-phosphatidylcholine (DMPC) and dimyristoyl-L-alpha-phosphatidyl-L-serine (DMPS) can form BLMs on PPy film surface but dimyristoyl-L-alpha-phosphatidylglycerol (DMPG) and didodecyldimethylammonium bromide (DDAB) can not do so, indicating the formation of PPy supported bilayer lipid membranes (s-BLMs) is dependent on the chemical structure of the lipids used. The self-assembly of DMPC induces a smoother topography than the PPy layer with rms roughness decreasing from 4.484 to 2.914 nm convinced by atomic force microscopy (AFM). Impedance spectroscopy measurements confirm that the deposition of BLM substantially increases the resistance of the system indicating a very densely packed BLM structures. The little change of PPy film in capacitance shows that solvent and electrolyte ions still retain within the porous PPy film after BLM deposition. Therefore, the PPy supported BLM is to some extent comparable to conventional BLM with aqueous medium retaining at its two sides. As an example and preliminary application, horseradish peroxidase (HRP) reconstituted into the s-BLM shows the expected protein activity and can transfer electron from or to the underlying PPy support for its response to electrocatalytic reduction of hydrogen peroxide in solution. Thus the system maybe possesses potential applications to biomimetic membrane studies.

Biosensing Techniques↗
PubMed2005

Alternate assemblies of platinum nanoparticles and metalloporphyrins as tunable electrocatalysts for dioxygen reduction.

Through electrostatic layer-by-layer (LBL) assembly, negatively charged citrate-stabilized platinum nanoparticles (PtNPs) and positively charged [tetrakis(N-methylpyridyl)porphyrinato] cobalt were alternately deposited on a 4-aminobenzoic acid-modified glassy carbon electrode and also on indium tin oxide substrates, directly forming the three-dimensional nanostructured materials. Thus-prepared multilayer films were characterized by UV--visible spectroscopy, surface plasmon resonance (SPR) spectroscopy, atomic force microscopy (AFM), and cyclic voltammetry. Regular growth of the multilayer films is monitored by UV--visible spectroscopy and SPR spectroscopy. AFM provides the morphology of the multilayer films. The PtNPs containing multilayer films exhibit high electrocatalytic activity for the reduction of dioxygen with high stability. Rotating disk electrode voltammetry and rotating ring-disk electrode voltammetry demonstrate that the PtNP-containing multilayer films can catalyze an almost four-electron reduction of O(2) to H(2)O in an air-saturated 0.5 M H(2)SO(4) solution. Furthermore, the electrocatalytic activity of the films could be further tailored by simply choosing different cycles in the LBL process or more specifically the amount of the assembly components in the films. The high electrocatalytic activity and good stability for dioxygen reduction make the PtNP-containing multilayer films potential candidates for the efficient cathode material in fuel cells.

Metalloporphyrins↗
PubMed2004

Robust core-shell supramolecular assemblies based on cationic vesicles and ring-shaped [Mo154] polyoxomolybdate nanoclusters: template-directed synthesis and characterizations.

Substantial progress has been made recently in extending the supramolecular assembly of biomimetic structures to vesicle-based sophisticated nanocomposites and mesostructures. We report herein the successful preparation of unilamellar surfactant vesicles coated with a monolayer of ring-shaped [Mo(154)] polyoxometalate (POM) nanoclusters, (NH(4))(28)[Mo(154)(NO)(14)O(448)H(14)(H(2)O)(70)]. approximately 350 H(2)O, by coulomb attractions using preformed didodecyldimethylammonium bromide (DDAB) surfactant vesicles as templates. The resultant vesicle-templated supramolecular assemblies are robust (they do not disintegrate upon dehydration) both at room-temperature ambient and vacuum conditions, as characterized by conventional transmission electron microscopy (TEM) and atomic force microscopy (AFM). The flexibility of the complex soft assemblies was also revealed by AFM measurements. The effect of POM-vesicle coulomb attractions on the dimensions of the templating vesicles was also investigated by using dynamic light scattering (DLS). Although origins of the structure stability of the as-prepared supramolecular assemblies are not clear yet, the nanometer scale cavities and the related properties of macroions of the POM clusters may play an important role in it.

Journal Article↗
PubMed2004

[Grading of intrahepatic cholestasis of pregnancy].

OBJECTIVE: This study was to evaluate the grading of intrahepatic cholestasis of pregnancy (ICP). METHODS: All 278 ICP cases were collected in the First Affiliated Hospital of Chongqing Medical University between Jan 1999 and May 2003. They were graded into mild ICP and severe ICP based on liver function test. Outcome of pregnancy and perinatal mortality were assessed. RESULTS: One hundred and ninety two cases were diagnosed as mild ICP while 86 cases were as severe ICP. There was significant difference in the average time of expectant therapy (10.3 +/- 4.8 vs 19.1 +/- 6.4 days) and gestational weeks (35.8 +/- 1.6 vs 37.7 +/- 1.9) between severe ICP and mild ICP groups (P < 0.01 and P < 0.001). The incidences of meconium passage, newborn asphyxia and admissions to neonatal intensive care unit in severe ICP were significantly higher than that in mild ICP. These were 38.4% vs 9.4%, 12.8% vs 4.2%, and 30.2% vs 9.4%, respectively. The difference of perinatal mortality between the patients with ICP diagnosed by using and not using the grading system (0.7% - 1.2% vs 3.9% - 6.0%) was statistically significant (P < 0.01). CONCLUSION: Grading of ICP based on liver function test may improve perinatal prognosis.

Cholestasis, Intrahepatic↗
PubMed2004

[Gene expression profile of human adenocarcinoma by cDNA microarray and clustering].

OBJECTIVE: To investigate the gene expression profile of human gastric adenocarcinoma by means of cDNA microarray and to analyze its biological significance. METHODS: Paired tumor and non-tumor specimens from 18 cases of advanced gastric adenocarcinoma were studied. Total RNA was isolated and labeled by reverse transcription reaction with cy5 and cy3 for cDNA probe. cDNA microarrays containing 148 genes were hybridized with labeled cDNA probe. Data from cDNA microarray experiments were analyzed by average-linkage hierarchical clustering and significance analysis of microarrays (SAM). RESULTS: Eighteen tumor and non-tumor specimens were clearly divided by clustering analysis. Three features of gene expression profile were found in gastric adenocarcinoma and non-tumor tissues. The profile of differential gene expression in tumor and non-tumor tissues was mainly shown in feature B and feature C. In gastric adenocarcinoma tissues, the expression of genes in feature B was lower and that in feature C was higher. The profile of differential gene expression among gastric adenocarcinoma tissues was found in feature A. In feature A, the profile of similar gene expression was found in paired tumor and non-tumor tissues from 13 patients. SAM analysis showed that 19 genes in feature B and 12 genes in feature C were of significant difference between tumor and non-tumor specimens. The expression levels of genes related to cell cycle, growth factor, cell adhesion, and matrix remodeling were higher or lower in gastric adenocarcinoma tissues. CONCLUSION: Data from cDNA microarray experiments can clearly distinguish gastric adenocarcinoma from non-tumor tissues. The profiles show that gene expression in gastric adenocarcinomas is both homogeneous and heterogeneous. The homogeneous gene expression profile is found in both tumor and non-tumor tissues from 13 patients, suggesting that some gene aberrance is an early event of carcinogenesis of gastric adenocarcinoma. This study provides not only a new molecular basis for understanding biological properties of gastric adenocarcinoma, but also useful resources for future development of diagnostic and prognostic markers for gastric adenocarcinoma.

Adenocarcinoma↗
PubMed2004

[Clinical analysis of 38 elderly patients with early double primary cancers].

OBJECTIVE: To study the clinical features and proper treatment of 38 elderly patients with early double primary cancers. METHODS: Thirty-eight elderly patients with early double primary cancers treated from January 1980 to March 2003 were retrospectively reviewed for involved organs, treatment and prognosis. RESULTS: Digestive tract was the most frequently involved, followed by urogenital system and lung. Long-term results of endoscopic mucosal resection (EMR), operation and radiotherapy were superior to other methods. The prognosis of gastrointestinal carcinoma was better than that of prostate carcinoma and hematopoietic system. The operation rate decreased with increasing age. The 5-year survival rates of EMR, operation and radiotherapy were 85.7%, 71.1% and 75.0%, respectively. The medium survival time was 120 months in first cancer and 39 months in the second primary cancer. The 5-year survival rates of the first cancer and second primary cancer were 88.6% and 53.8%. CONCLUSION: Yearly follow-up for elderly patients with endoscopy, beta ultrasonic scan and X-ray contribute to finding of early double primary cancers. Operation is the best treatment of early double primary cancers. Endoscopic mucosal resection is especially suitable for old patients with digestive tract and bladder cancer.

Aged↗
PubMed2004

[Effect of inflammatory chronic pelvic pain syndrome on the levels of prostatic specific antigen].

OBJECTIVE: To investigate the levels of prostatic specific antigen (PSA) in patients with chronic prostatitis. METHODS: Forty-five patients with diagnosed inflammatory chronic pelvic pain syndrome (NIH category III A prostatitis) were inquired about the history symptoms and signs of prostatitis, and underwent digital rectal examination of the prostate as well as analysis of expressed prostatic secretions (EPS). Bacterial infection was also analyzed by pre- and post- massage test (PPMT), and PSA in the blood was detected. Thirty healthy males without inflammation in EPS were selected as controls. RESULTS: In 45 cases of the patients with NIH category III A prostatitis, the PSA level in the blood was 2.41 +/- 0.64 microg/L, and that in the control group was 0.93 +/- 0.52 microg/L, with significant difference (P < 0.05). And among the 45 patients there were 6 (13.3%) whose PSA levels were over 4.0 microg/L, but there was only 1 in the 30 control males (3.3%). In III A prostatitis, the PSA level was elevated with the increase of inflammation in EPS, but with no significant difference. CONCLUSIONS: In the diagnosis of prostate diseases, it should be taken into account that chronic non-bacterial prostatitis might elevate the level of PSA to a certain extent.

Adult↗
PubMed2003

[Cloning and tissue expression analysis of up-regulated cDNA fragment in human gastric cancer].

OBJECTIVE: To identify novel human gastric cancer-associated susceptibility gene for early diagnosis and treatment of gastric cancer. METHODS: A primer was designed for 3'-rapid amplification of cDNA end(RACE) and amplified fragments were cloned, then they were analyzed by sequencing. Compared with ESTs in Genbank, the EST fragment represented a novel gene. Combination of Northern blot and virtual Northern and multiple tissues Northern blot, expression of the cDNA in multiple normal and carcinoma tissues were analyzed. RESULTS: One of the important cDNA bands with poly(A) tail was cloned. This band was named W41. Sequence analysis showed that W41 consists of 533 bp. Basic local alignment search tool analysis revealed that W41 has low identity with any genes from GenBank. This sequence data was submitted to GenBank with accession No. AF 325202. Northern blot revealed that W41 presented higher expression in gastric cancer tissue than in normal tissue. Multiple tissue Northern blot revealed that W41 presented higher expression in multiple cancers than in normal tissues. Virtual Northern revealed that the cDNA presented higher expression in tumor series analysis of gene expression libraries than in normal. CONCLUSION: A novel human gastric cancer-associated cDNA fragment was identified.

Blotting, Northern↗
PubMed2003

[Clinical study of immediate implant].

OBJECTIVE: To evaluate the clinical result of immediate implant. METHODS: 32 cases underwent immediate implant surgery for 59 implants simultaneously when the teeth or roots extracted. 55 implants were placed with bone grafts or bone substitutes. The second stage operation were performed in the sixth month and ceramic crown were fixed in the seventh to eighth month postoperatively, the follow up were mean 39 months. RESULTS: One implant was lost. Bone resorption of alveolar crest was observed in 4 implants. Mean resorption was 2 mm. CONCLUSIONS: The result of immediate implant is predictable, the advantages are avoiding the alveolar bone resorption after teeth extraction, implant could be placed in an ideal position; less operation trauma, good esthetics results.

Adult↗