Biomedical subjects

Gang Shi

Publications and source records attributed to Gang Shi.

6 recordsLinked to original sources

PubMed2006

Acidity adjustment of HZSM-5 zeolites by dealumination and realumination with steaming and citric acid treatments.

This article describes a novel method for acidity adjustment of HZSM-5 zeolites with steaming and citric acid treatments and demonstrates the realumination effect of citric acid on HZSM-5 zeolites dealuminated by steaming. A series of modified HZSM-5 zeolites were prepared by streaming and/or acid treatments and characterized by means of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), (27)Al MAS NMR spectroscopy, hydroxyl infrared spectroscopy (OH-IR), pyridine-adsorbed infrared spectroscopy, and N(2) adsorption in the present investigation. The results showed that compared with single HCl or citric acid treatment, steaming treatment, and steaming/HCl treatments, citric acid treatment after steaming exclusively increased the amount of framework Al due to reinsertion of extraframework Al into the defective sites of the steamed HZSM-5 framework. This realumination effect of the citric acid treatment on the steamed HZSM-5 zeolite, which is reported here for the first time to the best of our knowledge, could nearly recover the pore structure of the steamed zeolite to that of the parent HZSM-5 zeolite and appropriately tailor the amount and strength of different acid sites, which sheds light on optimizing the physicochemical properties of HZSM-5 zeolites. It was also found that the steaming treatment prior to the citric acid treatment was the precondition of the realumination of HZSM-5 zeolites, suggesting that the lattice defect sites generated during steaming were necessary for citric acid to work.

Journal Article↗

PubMed2006

Expression of pituitary adenylate cyclase-activating polypeptide 1 and 2 receptor mRNA in gallbladder tissue of patients with gallstone or gallbladder polyps.

AIM: To detect the expression of pituitary adenylate cyclase-activating polypeptide receptor 1 (VPCAP1-R)and VPCAP2-R mRNA in gallbladder tissues of patients with gallstone or gallbladder polyps. METHODS: The expression of VPCAP1-R and VPCAP2-R mRNA in gallbladder tissues was detected in 25 patients with gallstone,8 patients with gallbladder polyps and 7 donors of liver transplantation by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The VPCAP2-R mRNA expression level in the control group (1.09+/-0.58) was lower than that in the gallbladder polyp group (1.64+/-0.56) and the gallstone group (1.55+/-0.45) (P<0.05) while the VPCAP1-R mRNA expression level in the control group (1.15+/-0.23) was not apparently different from that in the gallbladder polyp group (1.28+/-0.56) and the gallstone group (1.27+/-0.38). CONCLUSION: The abnormal expression of VPCAP2-R mRNA in gallbladder tissue may play a role in the formation of gallbladder stone and gallbladder polyps.

Adult↗

PubMed2005

Fabrication and optimization of the multiplex PCR-based oligonucleotide microarray for detection of Neisseria gonorrhoeae, Chlamydia trachomatis and Ureaplasma urealyticum.

To detect and identify the pathogens responsible for sexually transmitted diseases (STDs) at the early stage of infection and with a high throughput, a new microarray with a bifunctional probe modification was prepared using Neisseria gonorrhoeae, Chlamydia trachomatis and Ureaplasma urealyticum as a model system. During the fabrication of the microarray, an asymmetric fluorescently labeled multiplex PCR was introduced. The fabrication optimization proved that the best hybridization results would be obtained by spotting N. gonorrhoeae probe at a position near the side of the fluorescently labeled reverse primer within its target gene and spotting each probe at a concentration of 50 microM onto the aldehyde-derived glass slides using spotting solution S1 and using hybridization solution H2 for hybridization. The probes designed by our laboratory could specifically discriminate the pathogens of N. gonorrhoeae, C. trachomatis and U. urealyticum in the presence of the internal control on the microarray simultaneously and separately. By incorporating the key features of DNA microarray with those of multiplex PCR, the microarray provides a fast high throughput platform for multiple infections and multiple samples to be detected and identified simultaneously for STD clinics. It also provides a new platform for other diseases and gene mutations to be detected and identified at a high throughput.

Chlamydia trachomatis↗

PubMed2005

Production of native protein by using Synechocystis sp. PCC6803 DnaB mini-intein in Escherichia coli.

To directly express native recombinant proteins in Escherichia coli, a new expression vector pSB was constructed using Ssp DnaB mini-intein. Using the vector, native proteins could be produced with the help of C-terminal self-cleavage of the intein. In this study, we cloned hIFNalpha-4 gene into pSB and used E. coli strain Origami B (DE3) as the host. Expression experiments were carried out both in Shake flasks and a 5 L bioreactor. The results indicated hIFNalpha-4 could be expressed in the form of soluble protein with correct folding in E. coli. The maximal hIFNalpha-4 content was 21.7% of total protein, and the antiviral activity of the protein was 1.2x10(8 )IU mg(-1). Overall, good effects were achieved with this system. This intein-mediated protein expression system opens up a useful method for production of native recombinant protein in E. coli.

Antiviral Agents↗

PubMed2004

[Effect of lycopene on DNA oxidative damage of cells in rats].

OBJECTIVE: Observe the protective effect of Lycopene(LP) on DNA damage. METHODS: Rats were given LP after 4 weeks, the DNA break in peripheral blood lymphocytes and liver cells from the rats were analyzed with single cell gel electrophoresis. RESULTS: Compared with control, the damage of DNA in LP group were reduced significantly(P < 0.05). CONCLUSION: LP could protect DNA damage of peripheral blood lymphocytes and liver cells in rats.

Animals↗

PubMed2003

[Effect of lycopene on the function of antioxidative enzyme system in rats].

In order to observe the effect of Lycopene(LP) on antioxidation in rats, the rats were given LP by oral. After 4 weeks the activity of SOD, MDA and GSH-Px, T-AOC, GSH, CAT in serum and liver were measured respectively. The result showed that the activities of SOD, T-AOC and GSH-Px in LP group were increased and the concentrations of MDA were decreased significantly(P < 0.05) compared with control group. LP could increase antioxidative effect and reduce lipid peroxidation in Wistar rats.

Animals↗