Biomedical subjects

Ting Guo

Publications and source records attributed to Ting Guo.

23 records · Page 2Linked to original sources

PubMed2005

Effect of femoral nutrient artery ligature on radionuclide uptake in rabbits.

To elucidate the effect of damaging the nutrient artery to a long bone, we used radionuclide imaging to survey the change of femoral blood supply after ligating the nutrient artery in rabbits. The radionuclide uptake of the femoral shaft, upper and lower metaphysis, and epiphysis decreased significantly at 1 hr postoperation (0.66, 0.74, 0.81, respectively, p <0.05), were close to normal on day 4 (0.96, 0.98, 1.02, respectively, p >0.05), slightly exceeded the contralateral level at 9 and 12 days, and returned to normal on day 16. This study shows that ligation of the nutrient artery of a long bone leads to an immediate decrease in the bone blood flow. However, so long as anastomoses among other bone vessels are intact, the recovery rate is speedy, and long-term, serious disorders of the bone blood supply do not ensue.

Animals↗

PubMed2004

Alkanethiol-induced structural rearrangements in silica-gold core-shell-type nanoparticle clusters: an opportunity for chemical sensor engineering.

Electrostatically bonded SiO2.Au nanoparticle clusters form by reaction of 3-aminopropylsilane-modified SiO2 spheres (470 nm) with citrate-coated gold nanoparticles (9.7 nm) in water. Reaction of the clusters with 0.01 M KBr or HCl solution induces desorption of the gold nanoparticles within minutes. Reaction of the clusters with alkanethiols CnH2n+1SH (n = 2-18) at 80 degrees C causes the gold nanoparticles to form stringlike gold nanoparticle structures for thiols with short alkane groups (n = 2, 3, 4) and hexagonally packed arrays of gold nanoparticles for thiols with long alkane groups (n = 5-18) on the silica surfaces. The structural changes indicate that the bonding between Au and SiO2 nanoparticles has changed from electrostatic to van der Waals. Elemental analyses show that the reaction with hexanethiol does not affect the Au/Si/O composition of the SiO2.Au cluster, and Raman spectra on the hexanethiol-reacted cluster indicate the formation of a thiol SAM on the gold nanoparticles. The thiol-reacted SiO2.Au clusters display characteristic shifts of the absorption maxima in the visible spectra, and there is an inverse relation between these shifts and the lengths of the alkyl groups in the thiols. This relationship can be understood in terms of the free electron model for metals. The use of SiO2.Au nanoparticle clusters as coulometric sensors for the qualitative detection of thiols is discussed.

Journal Article↗

PubMed2004

[Cloning and sequencing of the upstream of mouse dentin sialophosphoprotein promoter].

OBJECTIVE: To clone and sequence the upstream of mouse dentin sialophosphoprotein promoter. METHODS: Genomic DNA was obtained from Balb/c mouse blood. The upstream of mouse dentin sialophosphoprotein promoter segments was obtained by PCR. Then the segments were inserted into T-vector. The plasmids were identified by digestion with the restriction enzyme analysis. The positive clone was sequenced and compared with Genebank. RESULTS: The upstream of mouse dentin sialophosphoprotein promoter was divided into three sequences and three different target segments with 997 bp, 1004 bp and 674 bp in length were obtained. After identified, sequenced and compared with Genebank, the sequences of the segments were consistent with those displayed on Genebank by 99%. CONCLUSION: The clone of the upstream of mouse dentin sialophosphoprotein promoter was successful. This work will help to study the regulation of DSPP expression.

Animals↗

PubMed2003

[Cbfa1 induces the expression of the mineral-related proteins in human dental papilla cells].

OBJECTIVE: To explicit whether the expression of the mineral-related proteins is regulated by cbfa1 in human dental papilla cells. METHODS: Human dental papilla cells were cultured in vitro and transfected with pcDNA3-cbfa1 recombinant plasmids. After selected with G418 sulfate, a cell clone named PC-3, which could stably express the cbfa1 mRNA and protein, was proved by PCR and western blot. Then the amount of ALP and OC and the expression of OPN, BSP, ON, DMP1, DSP and DSPP were detected by immunohistochemistry, Western blot and PCR methods. RESULTS: We established the human dental papilla cells model PC-3 which could stably express the cbfa1 mRNA and protein. Compared with normal cells, a lot of mineral-related proteins such as ALP, OC, OPN, BSP, ON, DMP1 were upregulated in PC-3 cells. CONCLUSIONS: In human dental papilla cells, cbfa1 can induce the expression of most mineral-related genes and proteins. It may implicate that cbfa1 must play a key role during tooth development and mineralization.

Alkaline Phosphatase↗

PubMed2002

Compact 50-Hz terawatt Ti:sapphire laser for x-ray and nonlinear optical spectroscopy.

We report a high-repetition-rate, compact terawatt Ti:sapphire laser system. The oscillator produces an 82-MHz pulse train consisting of broad-bandwidth pulses of 0.5-nJ/pulse energy and of 9-fs pulse duration. The spectrally shaped, lambda/4 regenerative amplifier supports an 80-nm bandwidth. A single 50-Hz repetition-rate pump laser pumps both the regenerative amplifier and a multiple-pass amplifier. The final output from this laser is a 50-Hz pulse train made from pulses of 53 mJ/pulse energy and of 24-fs pulse duration. For generating ultrafast x-ray pulses, 90% of the energy from the final output of a 28-mm-diameter (1/e2) beam is focused onto an ultrafast x-ray wire target. The energy conversion efficiency from optical (800-nm central wavelength) to x-ray (characteristic lines of K(alpha) from Cu at 8 keV) pulses is estimated to be 7 x 10(-5). This laser system can also generate a lower-peak-power, dual-pulse output that can excite, simultaneously and coherently, Raman modes within an adjustable bandwidth (up to 700 cm(-1)) and at a tunable central vibrational frequency. Preliminary results for the generation of dual-pulse output and ultrafast x rays are presented.

Journal Article↗