Objective To ascertain the dose levels to personnel from the activation products in the radiotherapy place of a proton acceterator and to provide technical basis for protection design of the treatment place and the personnel's radiation protection.Methods A PROTEUS 235 proton therapy system was analyzed for the potentials to produce activated nuclides in the air during its operation.The concentrations of the main radionuclides and the resultant personnel doses were estimated.Results The activity concentrations of activated nuclides were 15O 4.1 × 10-2,13N 3.3 × 10-2,41 Ar 6.2 × 10-3 and 11 C 2.0 × 10-2 Bq · cm-3,respectively,in proton accelerator hall,whereas those in the proton beam radiotherapy room were only about 5％ of the corresponding values in the proton accelerator hall.The annual doses to the radiation workers from immersion external exposure due to air activation were less than 1 and 0.1 mSv,respectively,when entering the proton accelerator hall 5 and 30 min after beam stopping;whereas those were 1.3-2.0,0.7-1.2 and 0.3-0.6 mSv,respectively,when entering the therapy hall 0,5 and 15 min after beam stopping.Conclusions The personnel doses received from activated nuclides in the air in the radiotherapy place of a proton acceterator are unignorable.The contribution to doses from immersed external exposure of 15O,13N,41Ar and 11C should be taken into full considerations,with necessary protection measures needed.

Objective To understand the functional status and radiation protection requirements of helical tomotherapy (TOMO) unit when it is applied in clinic treatment so as to promote the construction of TOMO quality control system.Methods A helical tomotherapy unit with a type of tomotherapy Hi-Art was employed as the radiotherapy unit.A series of tests and analyses on dosimetric and radiation safety performance parameters of the TOMO unit were conducted with the use of a A1SL ionization chamber,a set of solid water equivalent phantoms and other test equipments.The performance parameters were compared with that of a conventional 6 MV accelerator with a type of ARTISTE.Results The deviations of static and dynamic output dose were-1.51％ and 1.18％,respectively.The values of PDD10/PDD1.5 and PDD20/PDD1.5 were 0.608 and 0.318 within the range of X-ray quality parameters calibration.Under the different field conditions of 40 cm × 5 cm,40 cm × 2.5 cm and 40 cm × 1 cm,the stability of transverse/longitudinal dose distribution curve was no more than 1.20％ and the offset distance of Jaw width was smaller than 0.5 mm.Radiation leakage ratio of the treatment rotating center from the muhileaf collimator (MLC) was 0.20％.No matter the average or the maximum value of the leakage radiation from couch plane was less than 0.02％.Conclusions The performances and testing requirements of TOMO unit are different from a conventional electron linear accelerator,the quality control index of TOMO unit should be set seperately and tested strictly in terms of the specific requirements of the unit by complying with the QC programme.The reliable quality control system should be established and effectively implemented to serve the radiotherapy quality and radiation safety effectively in the tomotherapy.

Objective To describe MRI findings of acute spinal cord decompression sickness.Methods MRI findings of 5 cases with clinical definite acute spinal cord decompression sickness were retrospectively analyzed.The main clinical informations included underwater performance history against regulations,short-term complete or incomplete spinal cord injury symptoms after fast going out of water,sensory disability and urinary and fecal incontinence,etc.Results Spinal cord vacuole sign was found in all 5 cases.Iso-signal intensity(n=3),high signal intensity(n=1),and low signal intensity (n=1)was demonstrated on T1 WI,and high signal intensity(n=5)was found on T2 WI.Owl eye sign was detected in 3 cases,and lacune foci were seen in 2 cases.Conclusion MRI findings of acute spinal cord decompression sickness had some characteristics,and it was easy to diagnose by combining diving history with clinical manifestations.

Objective To analyze the mid- and long-term results after coronary artery bypass graft surgery (CABG), to evaluate the accuracy of multi-detector CT coronary angiography (MDCT) on the graft patency status and to compare the patency for different grafts. Methods One hundred and one cases underwent CABG from June 1992 to March 2008 were followed up by searching the database of MDCT (42 cases) and selective coronary angiography (SCA, 59 cases). The mean following up period was (66.79 ±44.27) months. Three hundreds and 10 grafts including 115 arterial and 195 venous were analyzed.A comparison of the patency rate between the arterial and venous grafts was also carried out. At the mean time, 2 groups were divided according to the paft lesions( patency of not). Uunivariate analysis and Logistic regression analysis were made for statistics. Results At the follow-up of (53.93 ± 36.80) months, the patent rate of LIMA, RA, SV and CV examined by MDCT was 94.7%, 92.0%, 85.9% and 60.0%, respectively. The patent rate for MDCT patients with angina was 83.5%, and 95.2% for angina-free group ( P = 0.046). At the follow-up of (75.95 ±47.09) months, the patent rate of LIMA, RA, SV and CV examined by SCA was 87.1%, 81.0%, 53.6% and 57. 1%, respectively. In SCA patients the patent rate was 62.0% for angina group and 100% for angina-free group ( P = 0.025 ). According to logistic regression analysis, only the postoperative period was statistically related to the graft lesion. Conclusion MDCT could find out the occlusions and obvious stenoses of the grafts after CABG. It might be served as a noninvasive method to evaluate the grafts patency postoperatively. The mid- and long-term patency of arterial grafts is better than venous grafts. Graft lesion is an important factor leading to postoperative recurrent angina pectoris. The severity of the graft lesion has a close relation to the lenth of postoperative period.

BACKGROUND: Belladonna drugs have been widely used in clinic in our country to improve microcirculation, or as a herbal anesthetic drug. However,there are few reports regarding the animal experiments on belladonna alkaloid against morphine addiction further OBJECTIVE: To observe the effects of belladonna alkaloid combined with morphine on morphine(Mor)-addicted mice so as to provide an experimental basis for development of belladonna to morphine addiction.DESIGN: A completely randomized-controlled study based on the experimental animals.SETTING: Laboratory of physiology of a medical college.MATERIALS: The study was performed at the Laboratory of Physiology of Medical Department of Hebei Engineering College from June 2004 to August 2004. Fifty 2-month old male healthy Kunming mice of clean grade with a body mass of(20±2) g were obtained from Experimental Animal Centre of Hebei Medical University.METHODS: According to evaluation index of dependence in Morphine-addicted animals, we chose pain threshold and naloxone-urged jumping response as items to observe. Fifty mice were randomly divided into 5 groups with 10 mice each, which were the control group (saline), the morphine group, the scopolamine(Sco)group, the anisodamine(Ani), atropine(Atr)group. The corresponding drugs or saline was administered by intraperitoneal (I. P.) injection once a day for 7 days. The pain threshold at 1 hour after I. P. Injection of drugs was observed from day 1 to day 7 by hot-plate method. Mice were given I.p. Injection of naloxone (Nal, 5 mg/kg ) 6hours after the last injection. The jumping times within 30 minutes were observed to evaluate the ,formation of the Morphine addiction.Nal-urged mice.RESULTS: The pain threshold of the mice in Morphine group was decreased significantly, and the jumping times and jumping rate were obviously increased compared with that of the control group( P ＜ 0.05 or P ＜ 0.01).The co-administration of Sco-Mor mixtures for 7 days significantly increased the pain threshold of Mor-dependent mice( P ＜ 0.01) and markedly decreased the jumping times and the jumping rate( P ＜ 0. 05) . Atr-Mor and Ani-Mor had a weak effect on the elevation of the pain threshold of Mor-dependent mice, but had strong effects on the decrease of the jumping times and the jumping rate( P ＜ 0. 01 ).CONCLUSION: Belladonna alkaloids all could antagonize Mor-dependence in mice at different degrees, which provide an important experimental evidence to develop belladonna drugs for preventing opium addiction.

ObjectiveTo monitor the early blood lactic acid concentration of patients with severe trauma who have been experienced routine surgery or damage control surgery,and explore the influence of surgical methods for the early lactate clearance rate.MethodsSelected 40 patients with severe trauma,they were divided into two groups with 20 cases each in accordance with the adopted operation mode,reference group by damage control surgery,and control group by routine surgery.Recorded acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ ) in patients after admission,blood lactic acid concentration at 6 h after admission and admission,calculated the early lactate clearance rate.ResultsIn reference group,blood lactic acid concentration at 6 h after admission was significantly lower than that in control group[ (3.5 ± 1.1 )mmol/L vs.(4.2 ± 1.4) mmol/L,P＜ 0.05 ],early lactate clearance rate was higher than that in control group [ (24.6 ± 6.3 )％ vs.( 11.4 ± 5.3 )％,P＜ 0.05 ].Conclusions Damage control surgery in patients with severe trauma in favour of the early removal of lactic acid,maintaining the homeostasis of the organism,is the key to improve the achievement ratio of treatment with severe trauma.

Objective To explore the clinical risk factors of ventilator-associated fungal pneumonia (VAFP) in emergency intensive care unit.Methods One hundred and ninety-seven consecutive patients with 121 males and 76 females,aged from 17 to 98 years met the criteria of ventilator-associated pneumonia in emergency intensive care unit admitted from July 2009 to June 2014,were retrospectively evaluated.Those with mechanical ventilation less than 48 hours or treatment discontinued were excluded.Patients were divided into VAFP group and ventilator-associated non-fungal pneumonia group according to the results of fungal culture and microscopy.Univariate analysis was used to find out preliminary risk factors for VAFP,and then the ultimate independent risk factors were determined with multivariate stepwise logistic regression analysis.Results The occurrence of VAFP was 32.0 ％ (63 cases) out of 197 patients with ventilatorassociated pneumonia.In those 63 patients,there were 71 species found from fungus culture.Candida albicans counted for 33 (46.5％),Candida glabrata for 11 (15.5％),other Candida Albicans for 26 (36.6％).The preliminary univariate analysis showed that 19 factors were statistically significant,while multivariate stepwise logistic regression analysis revealed that acute physiology and chronic health evaluation Ⅱ score≥ 22,radiotherapy or chemotherapy,mechanical ventilation ≥14.11 days,use of antibiotics ≥14 days,use of glucocorticoid and other immuno-suppressants were independent predictors of VAFP,and the adjusted odds ratios with 95％ confidential intervals were 4.133 (2.831-6.033),2.977 (1.942-4.564),2.305 (1.439-3.736),1.988 (1.441-2.741),1.528 (1.337-1.746),respectively.Conclusion Higher APACHE Ⅱ score,radiotherapy or chemotherapy,prolonged use of mechanical ventilation,prolonged use of antibiotics,use of glucocorticoid and immunosuppressants are independent risk factors of VAFP.The incidence rate of VAFP may be reduced by improving patients' overall clinical setting,shortening the duration of mechanical ventilation and employment of antibiotics,and more strict guidelines to the application of glucocorticoid and immunosuppressants.

Objective To study the radiation dose level and dose distribution of leakage and scattering radiation in a helical tomotherapy (TOMO) room,and to identify the dose distribution characteristic which is different from the conventional radiotherapy so as to provide scientific data for the radiation protection of TOMO.Methods A helical tomotherapy facility typed Tomotherapy Hi-Art was employed as the radiotherapy device.The air kerma from leakage radiation and scattering radiation distributed on the couch plane and in TOMO room were detected mainly by GR-200A TLDs of LiF(Mg,Cu,P),while 100 Gy were being accumulated under the condition of simulation radiation treatment.Then,the leakage radiation ratio and scattering-leakage radiation ratio (the ratio of site radiation dose to isocenter standard output dose) were calculated.Results The radiation level and dose distribution of leakage radiation and scattering radiation in the TOMO treatment room were in bilateral symmetry to the rotation isocenter and the treatment couch longitudinal axis,and the radiation level in front of the radiotherapy device was significantly higher than that of the rear of the TOMO equipment.In the plane of treatment couch,the maximum leakage radiation ratio at the position 100 cm away from the isocenter was only 1.3 × 10-4,and the mean value of the leakage radiation ratio at the position 300 cm away from the isocenter was lower than 2.0 × 10-5.The scattering radiation at 200-300 cm away from the isocenter was accounted for 25％-30％ of the leakage radiation from the responding sites,and the indoor scattering radiation decreased faster than leakage radiation with the distance from the isocenter.Conclusions The radiation level of leakage and scattering in a TOMO room is significantly lower than that in a conventional radiotherapy room.

Objective To evaluate the effect of polydatin on neuropathic pain in rats.Methods Forty male Sprague-Dawley rats,aged 6-8 weeks,weighing 200-230 g,were randomly divided into 5 groups (n =8 each) using a random number table:sham operation group (group S),neuropathic pain group (group NP),polydatin 5 mg/kg group (group P1),polydatin 10 mg/kg group (group P2),and polydatin 20 mg/kg group (group P3).Neuropathic pain was induced by chronic constriction injury in NP and P1-3 groups.In group S,the sciatic nerve was only exposed but not ligated.In S and NP groups,normal saline 0.1 ml was injected intraperitoneally immediately after operation and at 1,3,5 and 7 days after operation (T1-4).In P1-3 groups,polydatin 5,10 and 20 mg/kg (in normal saline 0.1 ml) were injected intraperitoneally immediately after operation and at T1-4.At 1 day before operation (T0) and T1-4,the mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured.After measurement of pain threshold at T4,the rats were sacrificed,and L4-6 segments of the spinal cords were removed for determination of the expression of high-mobility group box 1 (HMGB1),Toll-like receptor 4 (TLR4),interleukin-1beta (IL-1β),tumor necrosis factor-alpha (TNF-α) and monocyte chemotactic protein-1 (MCP-1) by Western blot.Results Compared with group S,the MWT was significantly decreased,and the TWL was significantly shortened at T1-4 in group NP,the MWT was significantly decreased at T1-4,and the TWL was significantly shortened at T2-4 in group P1,the MWT was significantly decreased at T1-4,and the TWL was significantly shortened at T3.4 in group P2,the MWT was significantly decreased at T1-4 in group P3,and the expression of HMGB1,TLR4,IL-1β,TNF-α and MCP-1 was significantly up-regulated in NP,P1 and P2 groups (P＜0.05).Compared with group NP,the MWT was significantly increased at Tt-4,and the TWL was significantly prolonged at T1,2 in group P2,the MWT was significantly increased,and the TWL was significantly prolonged at T1-4 in group P3,the expression of HMGB1,TLR4,IL-1β,TNF-α and MCP-1 was significantly down-regulated in P2 and P3 groups (P＜0.05),and no significant change was found in the parameters mentioned above in group P1 (P＞0.05).Compared with group P1,the MWT was significantly increased at T4 in group P2,and the MWT was significantly increased at T14,the TWL was significantly prolonged at T3,4,and the expression of HMGB1,TLR4,IL-1β,TNF-α and MCP-1 was significantly down-regulated in group P3 (P＜0.05).Compared with group P2,the MWT was significantly increased at T3,4,and the expression of TLR4,IL-1β,TNF-α and MCP-1 was significantly down-regulated in group P3 (P＜0.05).Conclusion Polydatin can alleviate neuropathic pain through inhibiting inflammatory responses in the spinal cord of rats.

Objective To explore the effect of radon released from water on the indoor radon activity concentration in groundwater supplies.Methods Two groundwater supplies in a city were chosen.Radon concentrations in three kinds of water samples were determined by using a continuous radon monitor with air-water exchanger,including source water,finished water and tap water.The solid track detector was used to analyze the indoor radon concentration in water supplies.Results The concentrations of radon in source water,finished water and tap water were (7.59 ± 1.36),(3.56 ±0.86),(3.68 ±0.81)Bq/L and (12.19 ±0.57),(7.87 ± 1.12),(9.50 t 1.12) Bq/L,respectively.The concentration of radon was the highest in source water and at less varying level in finished water and tap water.Aeration and filtration tank process significantly decreased radon activity in water.Radon concentrations in aeration and filtration rooms were 4 218 Bq/m3 and 1 937 Bq/m3,respectively,which exceeded the limit in work place (1 000 Bq/m3).Conclusions Aeration and filtration workplaces for groundwater supplies were found to contain elevated radon concentrations in air,which was released from groundwater.Radon issues in groundwater supplies in China should be paid more attention.