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G Ban

Publications and source records attributed to G Ban.

4 recordsLinked to original sources
PubMed2005

Spectral discrimination of Cerenkov radiation in scintillating dosimeters.

Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size, their high voltage needed, and the correction needed for electrons make them unsuitable for use during patient treatment. We have developed a small (1-mm-diam and 1-mm-long active part), flexible, and water-equivalent dosimeter. It is suitable for photon and electron beams without corrections, and performs on line dose measurements. This detector is based on only one scintillating fiber and a CCD camera. A new signal processing is used to remove the effect of Cerenkov radiation background, which only requires a preliminary calibration. Central-axis depth-dose distribution comparisons have been achieved with standard ionization chambers, over a range from 8 to 25 MV photons and from 6 to 21 MeV electrons in order to validate this calibration. Results show a very good agreement, with less than 1% difference between the two detectors.

Calibration↗
PubMed2001

[The genotype analysis of glucose-6-phosphate dehydrogenase deficiency in Yunnan province].

OBJECTIVE: To identify glucose-6-phosphate dehydrogenase (G6PD) gene mutations in 23 patients with G6PD deficiency and to gain further understanding of the molecular and genetic background of G6PD gene in Yunnan province, China. METHODS: The mutations located in exons 2-12 and in parts of introns of G6PD gene were analyzed by amplification refractory mutation system(ARMS), natural and mis-match primer PCR/restrict enzyme, polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP ) analysis and automatic DNA sequencing. RESULTS: Among these 23 samples, 5 different point mutations in G6PD gene were identified, and they constituted 5 genotypes. There were 7 Han and 3 Dai patients with G487A mutation, 7 cases with both intron 11 T93C and C1311T mutations, 4 cases with intron 5 636 or 637 T-->del mutation, 1 case with G871A mutation, and 1 case with G487A/T93C/C1311T mutation. Two haplotypes, 93C/1311T and 93C/1311T/487A were identified in Yunnan. A strong association was observed between C1311T and the Nla III restriction site produced by intron 11 T93C. The findings of the investigators on IVS-5 636 or 637T-->del in Chinese, on G871A in mainland of China, and on G487A in the Han people of Yunnan have not been reported previously. CONCLUSION: G6PD deficiency is very heterogenous in Yunnan; G487A is one of the common mutations in that province and may be of different origins. Possibly IVS-11 T93C mutation is of non-African origin. IVS-11 T93C and C1311T might jointly result in G6PD deficiency. The above data on G6PD gene mutation types could be useful for clinical diagnosis, prevention of G6PD deficiency, and researches in the origin and migration of minorities in Yunnan or other regions.

Adolescent↗
PubMedDate not supplied

Immediate loading of 4 implants. A case report.

Despite the obvious benefits of two-stage implants, patients do experience discomfort as they have to continue wearing non-fixed total dentures whilst postoperative healing takes place. These patients would be more comfortable if a functional and esthetically pleasing solution could be arrived at in a shorter time. In an effort to achieve this, the scientific community has researched and fitted ''immediate load'' implants. The current literature states that this procedure, when fitting 4 or more interforaminal implants, is both predictable and reliable. The procedure increases neither the number of implant failures nor the amount of bone lost. In the case reported, 4 implants were inserted and a bar constructed. The practicality of this procedure is seen in reduced time and costs. An initial total denture was used at the start, first as a surgery guide, then as an individual tray for impression, and eventually as final total denture. Fixing the initial total denture to the implant, considerably reduced the time taken in the whole implant procedure and provided the patient with a more comfortable, pleasing solution. The use of the bar prevented the denture from moving, guaranteed full support from the implants, and reduced or prevented the bone loss seen in patients where non-implant supported total dentures have been used. This procedure had the additional benefit of versatility - as it could have been used as an intermediate stage towards providing a more complex prosthesis, such as a Toronto prosthesis.

Dental Implantation↗