Objective To develop measurement of reference air kerma for192Ir sources with NE 2570 electrometer,2571 ion-chamber and machining measured holder.Methods The measuring holder was placed at the distance of 1 m from the walls,the floor and ceiling,the ion-chambet was insert into the oolymethyl methacrylate(PMMA)jig of the measuring holder,lhe optimum distance is 16 cm from the source centre to ionchamber centre.The source was transmitted by the afterloding system to the plastic pipe to measure reference air kerma of the source.According to calibration factors from60Coγrays and 250 kV X rays with air exposure to calculated the air kerma calibration factor,the air kerma calibration factor of 192Ir soHree was calculated bv60Co γ rays and the effective energy of the 250 kV X ray beam.The scatter correction factor was giverl by the shadow shield experiment for the wails,the floor,the air and the measuring holder,the correction factors were given for the attenuation of primary photons in air and the electrons entering the air cavity are mainly generated in the innerwall of the chamber by 1079 report in IAEA.Results Two measuring methods were used for192Ir source undersame environment condition,the ion-chatuber and well-type chamber values are 1.584×1011Bq and 1.561×1011Bq respectively,and the relative deviation from them is within 1.4%,Conclusions The air kerma measurement of 192Ir source the ion-chamber with is not depended on the source geometry(point seurce,line source etc),the size.and the material of shell,the shape,the quality of materials and the size of the chamber.The uncertainty error of the air kerma is lessin comparison to the air exposure.

The femora! arteries in 38 rabbits were transected and repaired with autogenous venous grafts with different diameters. The measurements of blood flow, patency rate and thrombosis rate, and scanning electron microscopic examination were made over a period of 14 days. The result showed that a venous graftl with a diameter 20 per cent less than that of the recipient artery was most satisfactory.

BACKGROUND: Quite a number of in vitro experiments indicate that low dose He-Ne laser can stimulate the cell growth and blood vessel regeneration therefore to improve the damages caused by ischemia. However, it needs further study on the in vivo experiments.OBJECTIVE: To study the protective effects of intravascular low dose laser irradiation to ischemic reperfusion of rats and explore its mechanism.DESIGN: A randomised and controlled trial based on experinental animals.SETTING: Department of Neurology of a hospital of a university.MATERIALS: The experiment was completed in the Surgery Experimental Animal Center of West China Hospital of Sichuan University. Healthy male SD rats of class Ⅱ which aged between 5 to 6 months with weight of 372 to 418 grams[mean weight(388.48 ± 10. 57) g] were provided by Animal Research Center of Sichuan University.INTERVENTIONS: Middle cerebral artery ischemia model of rats was prepared. Forty SD rats were randomly divided into treatment group and control group with each of 20 rats. Intravascular low dose He-Ne laser irradiation was conducted to rats in treatment group one time every other day, 20 minutes per time and 3 times for a course. Vein puncture was conducted to rats in control group without laser input.MAIN OUTCOME MEASURES: Ratio of infarcted volume RESULTS: The ratio of the cerebral infarction volume in treatment group was (10.43 ± 1.04) and is much lower than that of control group(16.78 ± 1.12).There was statistical difference between two groups( t = 27.14, P ＜ 0.05).CONCLUSION: Intravascular low dose He-Ne laser irradiation has protective effects to cerebral ischemia of rats.

Objective To investigate the preventive effect of somatostatin and nitroglycerin on post-ERCP pancreatitis (PEP) and hyperamylasemia.Methods A total of 184 patients who underwent endoscopic retrograde cholangiopancreatograph (ERCP) were enrolled,and randomly divided into three groups to receive somatostatin or nitroglycerin or normal saline according to random number table.Incidence of PEP and hyperamylasemia were observed and compared among the three groups.Results Nine patients stopped the medication and dropped out of the study after occurence of adverse reactions from receiving nitroglycerin injections.The incidence rates of hyperamylasemia were 38.7％ (24/62),51.8％ (28/54) and 37.3％ (22/59) in somatostatin,nitroglycerin and control group respectively,with no significant differences among the three groups (P ＞ 0.05).The incidence rates of PEP were 6.4％ (4/62),9.3 ％ (5/54) and 23.7％ (14/59) in somatostatin,nitroglycerin and control group,respectively.The incidence rates of PEP in somatostatin and nitroglycerin group were both significantly lower than that in control group (somatostatin group vs control group:x2 =7.13,P =0.01 ; nitroglycerin group vs control group:x2 =4.22,P =0.03).There was no significant difference between somatostatin group and nitroglycerin group (x2 =0.32,P =0.41).Conclusion Somatostatin and nitroglycerin injections after ERCP show similar efficacy on preventing PEP,but the former is safer.Both have little effects on the prophylaxis of hyperamylaemia.

Objective To verify the reliability of TLD-based quality audit for radiotherapy dosimetry of medical electron accelerator in non-reference condition by monitoring the dose variations from electron beams with different field sizes and 45° wedge and the dose variations from photon beams with different field sizes and source-skin distance.Methods Both TLDs and finger ionization chambers were placed at a depth of 10 cm in water to measure the absorbed dose from photon beams,and also placed at the depth of maximum dose from electron beams under non-reference condition.TLDs were then mailed to National Institute for Radiological Protection,China CDC for further measurement.Results Among the 70 measuring points for photon beams,58 points showed the results with a relative error less than ± 7.0％ (IAEA's acceptable deviation:± 7.0％) between TLDs and finger ionization chambers measurements,and the percentage of qualified point numbers was 82.8％.After corrected by P,value,62 points were qualified and the percentage was up to 88.6％.All of the measuring points for electron beams,with the total number of 24,presented a relative error within ± 5.0％ (IAEA's acceptable deviation:± 5.0％) between TLDs and finger ioization cylindrical chambers measurements.Conclusions TLD-based quality audit is convenient for determining radiotherapy dosimetric parameters of electron beams in non-reference condition and can improve the accuracy of the measuring parameters in connection with finger chambers.For electron beams of 5 MeV ＜ E0 ＜ 10 MeV,the absorbed dose parameters measured by finger ionization chambers,combined with TLD audit,can help obtain the precise and reliable results.

Objective To develop a methodology for auditing dosimetric parameters using TLD for photon and electron beams in non-reference conditions.Methods The correction experiments have been developed for non-linear dose response,PAAM holder,energy,fading and dispersion using TLD for 60Co γ-ray,high energy X-ray and electron beams.The measuring method was set up for absorbed dose estimation by TLDs in water.3 photon beams and 2 electron beams were selected for research purposes,and 5 photon beams and 4 electron beams for reliability research.Results The research results were evaluated for60Co source,6,10,15 and 18 MV photon beams in non-reference conditions at off-axis,with the relative deviation within-0.1％-7.2％ at-off axis (IAEA's acceptable deviation:± 7.0％).The verification results were evaluated for 5 photon beams in non-reference conditions at on-axis,with the relative deviation are within 0.1％-7.0％.The verification results were evaluated for 4 electron beams in non-reference conditions,with the relative deviation within 0-4.7％ (IAEA's acceptable deviation:±5.0％).Conclusions It is convenient and accurate to use TLD method for quality audits for clinic dosimetry parameters in radiotherapy.Two kinds of IAEA TLD holders are feasible for use in TLD audits.Absorbed doses for high energy electron beam were corrected using plane parallel chambers and verified using TLD,with good results obtained.

Objective To explore the method for measuring and calculating both absorbed dose and effective dose received in organ and tissues of occupational workers by using TLDs for the implantation of 125Ⅰ seed sources.Methods The experiments with 60Co γ-rays were carried out for the stability.A group of TLD chips was exposed to 125Ⅰ seed sources to establish standard dose curve for air kerma.During the 125Ⅰ seed implantation, the TLD chips were pasted to 13 locations like thyroid inside and outside the lead aprons worn by occupational workers to measure average absorbed dose and calculate the absorbed doses and effectives to organs and tissues.Results For 3 cases of prostate cancers with implantation of 125Ⅰ seeds, the worker's organs and tissues received the absorbed dose 0.02 -3.80 μ Gy and effective dose 0.06- 1.81 μSv outside lead aprons and the highest absorbed dose 2.35 μ Gy and effective 0.02 μSv inside lead aprons, respectively, with more than 65.9% of rays shielded.For 3 cases of brain cancers with implantation of 125Ⅰ seeds, the workers received the absorbed dose 0.23 - 11.31 μGy and effective dose 0.88 - 4.07 μSv outside lead aprons and the highest absorbed dose 2.22 μ Gy and effective dose 0.09 μSv inside lead aprons, respectively, with more than 54.5% of rays shielded.For 3 cases of lung cancers with implantation of 125Ⅰ seeds, the workers received the absorbed dose 0.03 - 14.78 μGy and effective dose 0.35 -7.59 μSv outside lead aprons and the highest absorbed dose 4.09 μGy and effective 0.22 μSv inside lead aprons, respectively, with more than 58.4% of rays shielded.For 2 cases of mediastinum cancers with implantation of 125Ⅰseeds, the workers received the absorbed dose 0.06 - 74.91 μGy and effective dose 0.83 - 17.96 μSv outside lead aprons and the highest absorbed dose 10.29 μGy and effective 0.5 μSv inside lead aprons, respectively, with more than 85% of rays shielded.For one case of ovary cancer with implantation of 125Ⅰ seeds, the worker received the absorbed dose 0.09 - 14.29 μGy and effective dose 2.40 - 4.50 μSv outside lead aprons and the highest absorbed dose 7.77 μGy and effective 0.12 μSv inside lead aprons, respectively, with more than 34% of rays shielded.For one case of eye cancer with implantation of 125Ⅰ seeds, the workers received the absorbed dose 2.2 -39.84 μGy and effective dose 4.48 - 10.06 μSv outside aprons and the highest absorbed dose 5.19 μGy and effective 0.16 μSv inside aprons, respectively, with more than 54.6 % of rays shielded.Conclusions The method of using TLDs to measure the doses to the occupational workers in the course of the implantation of 125Ⅰ seed sources is simple and easy to operate.It would be an effective approach to protecting medical workers in the case of brachytherapy.

Purpose To observe the effect of Rongban Tongmai Granules on thrombosis and blood viscosity of in vitro rat model of blood stasis, and to study the activating blood circulation effect of the drug.Methods To observe the effect of the Rongban Tongmai Granules on thrombosis and blood viscosity of in vitro rat model of stasis, subcutaneous inject rat with epinephrine hydrochloride, and then copy "blood stasis" model by ice water stimulation in rats.Results According to a continuous 7 days′intragastric administration of Rongban Tongmai Granules, thrombus length of blood stasis model rats in vitro reduced significantly (P<0.05-0.01),wet and dry weight of thrombus reduced significantly (P<0.05), the shear rate of the whole blood viscosity under 100 S~(-1), 30 S~(-1), 5 S~(-1) decreased significantly as well (P<0.05-0.01), and the shear rate of whole blood viscosity had decreasing tendency under 200 S~(-1).Conclusion Rongban Tongmai Granules can inhibit thrombosis and lower blood viscosity.

Objective To investigate the inhibitory effect of Berberine hydrochloride alone or combined with antibiotics on the formation of Staphylococcus epidermidis biofilm and the expressions of relative genes in order to explore a new way to treat the infection induced by the bacteria.Methods Biofilm of Staphylococcus epidermidis was constructed in vitro first,and then Berberine hydrochloride alone or combined with norvancomycin,ciprofloxacin or erythromycin was used to affect the biofilm formation.Then the inhibition was detected by CRA,and the expressions of icaA and agr by the way of fluorescent quantitation RT-PCR.Results The effectiveness of Berberine hydrochloride on the expressions of icaA and agr in Staphylococcus epidermidis was not as better as the other antibiotics.When different-dosed berberine hydrochloride was combined with norvancomycin,ciprofloxacin or erythromycin to affect the biofilm,the inhibition on the expressions of icaA and agr showed a negatively dose-dependent fashion.Conclusion Berberine hydrochloride can inhibit the formation of the biofilm of Staphylococcus epidermidisthrough suppressing the relative genes,though not as good as the antibiotics,such as norvancomycin,ciprofloxacin and erythromycin.It should not be combined with these antibiotics because the effectiveness is antagonism.

Objective To evaluate the curative effect and optimal indications of reformed percutaneous lumbar diskectomy (RPLD) for the treatment of lumbar disc herniation.Methods One handred and thirty-three patients with lumbar disc herniation were treated by RPLD, of them, 20 cases were lumbar disc extrusion and 113 cases were lumbar disc protrusion. After the procedure, 85 patients underwent flush of intervertebral space with antibiotic saline and 48 patients underwent 10 ml(40?g/ml) medical ozone-injection inside the disc to prevent infection. All patients were followed up over the course of 3 months. The therapeutic effect was evaluated according to the MacNab criteria. Results All 133 cases underwent RPLD were successful. The total efficacy was 81.9%, There were no serious complications after operations. Conclusion RPLD is an effective method in the treatment of lumbar disc herniation. Both intradiscal ozone-injection or intradiscal antibiotic saline flush after RPLD can reduce the opportunity of infection.