Objective To establish a method for the determination of alum residual amount in Rhizoma Pinelliae Preparata from different companies,and to provide a scientific evidence for quality evaluation of Rhizoma Pinelliae Preparata.Methods Na2EDTA titration method was applied for the quantitative analysis.Results There were obvious differences in residual quantity of alum in Rhizoma Pinelliae Preparata from different companies.Conclusion The method is simple,reproducible and accurate,it can be used for the determination of alum residual amount in Rhizoma Pinelliae Preparata.

Objective To evaluate the strength of tobacco control at or below county-level governments of Zhejiang Province,to explore the strategies and measures on tobacco control,and promote a smoke-free government.Methods By multistage stratified random sampling method,12 government ageucies were selected in 4 counties.The information of tobacco control strength and smoke-free environment creation was collected by interview and field observation,and the scores were calculated by using the percentage assignment method.An intercept suuvey was carried out in four counties and there were 405 civil servants under investigation.The data were analyzed by frequency statistic and correlation analysis.Results The smoking rate of civil servants was 17.8％,and the secondhand smoking rate was 61.9％;84.7％ of civil servants adnmitted the harm of smoking and 96.8％ admitted the harm of secondhand smoking.Support for forbidding the cigarette advertisements was highest and increasing the cigarette price was the weakest.The scores of smoke-free environment creation of project counties showed that the average score was 50.60,Zhuji and Luqiao got a maximum score of 57.14,Haiyan got a minimum score of 42.86.The scores of tobacco control strength showed that the average score was 82.35,Zhuji got a maximum score of 92.16,followed by Luqiao,Jiande and Haiyan counties,82.35,80.39 and 74.51 respectively.The scores of tobacco control strength,include policy,political will,capacity,and tobacco control efforts were the highest in Zhuji county.The results of correlation analysis showed that the total score of tobacco control strength had significant association with the score of smoke-free environment creation,smoking rate of civil servants,and approval rate of anti smoking in public places (P＜0.05).Conclusion The overall situation of tobacco control strength at or below county-level governments of Zhejiang province is good,but there is a relative shortage of smoke-free environment creation.Civil servants master the knowledge related to tobacco and support tobacco control policy.We should further promote the construction of smoke-free government.More effective smoking control measures should be conducted in order to raise the strength of tobacco control and finally implement the tobacco control legislation.

Objective To understand the prevalence of tobacco use among college students in different populations by sex,age and major,and to provide evidence for smoking control and health decision.Methods A total of 4 638 college students selected in 21 colleges through stratified multi-stage cluster sampling from Zhejiang Province were surveyed by using questionnaire analysis.Indicators such as tried smoking,current smoking,and secondhand smoke exposure,etc.,were calculated by weight on age proportions from the numbers of college students in Zhejiang.Results The prevalence of tried smoking and currcut smoking among college students were 29.72％ and 10.57％,respectively.The prevalence of tried smoking was 46.52％ for men,18.25％ for women;28.57％ for undergraduate,31.53％ for junior college;the prevalence of current smoking was 18.86％ for men,3.86％ for women;8.88％ for undergraduate,13.23％ for junior college students.The snoking rate in college students increased with age,the group of ≥21 Years was the highest (37.87％,16.09％).The lowest level of smoking was medical student (21.76％,2.19％).The prevalence of secondhand smoke exposure in outdoor and indoor places,and dormitory among students were 65.49％,60.33％,and 23.66％,respectively.In the past 30 days,college students have seen tobacco advertisement (47.38％),smoking scenes (60.20％),and got tobacco related gifts (10.40％),free tobacco products (8.93％);college students have seen information about tobacco control (60.50％),cigarette pack warning labels (58.45％),and learned the tobacco knowledge in class in the past 12 months (14.03％).Conclusion Current prevalence of smoking in college students in Zhejiang province remained at a high level,the rate of secondhand smoke exposure is high and in college students there was lack of tobacco control education in class.The results indicated that the policy about tobacco control in school was not enough and the task of health promotion should be taken more arduously.

Objective Knowledge?based radiotherapy ( KBRT ) can reduce the plan quality variability induced by different experiences between physicians and improve the quality of treatment plans. Methods The Varian Rapid Plan system was used to train a dose?volume histogram ( DVH) prediction model. The obtained model was preliminarily applied to semi?automatic design of the preoperative treatment plans for rectal cancer. Eighty high?quality volumetric modulated arc therapy plans were imported into the model training set of the Rapid Plan system. The structures of the plans were matched to the corresponding labels and codes as listed in the library. The training started after the verification of prescription. The residual plots,regression curves,geometric plots for organ at risk ( OAR) ,in?field DVH plots,and model training logs were examined. After removal of the mismatch, the original plans were assessed to rule out outliers and influential data points. More similar plans may be added for another round of training. Ten KBRT plans were designed using the final model and compared with the clinical plans. Results For the two major OARs,the femoral head and bladder,the average goodness of fit of the principal component were 0?999 415/1.0 and 0?999 963/1.0 for the DVH model,and 0?999 651/1.0 and 0?999 945/1.0 for geometry?based expected dose model,respectively. In all the plans, 11 had Cook ’ s distance values exceeding the tolerance and 4 had studentized residual values exceeding the tolerance. The outliers were all kept in the training set to generalize the scope of the model. The 10 KBRT plans had significantly improved homogeneity indices for PGTV and PTV than the original plans (P=0?00,0?04).The 10 KBRT plans also had significantly reduced D50% to the femoral head and bladder as well as significantly reduced mean doses to the bladder than the original plans (P=0?042,0?000,0?005). Conclusions In this study,the Rapid Plan system is used to train a KBRT model for design of preoperative radiotherapy plans for rectal cancer. The results of preliminary application meet the clinical requirements.

Objective To compare the dosimetric difference of volumetric modulated arc therapy (VMAT) plans for the loco-regionally advanced nasopharyngeal carcinoma (NPC) patients using 6 MV X-ray flattening filter-free (FFF) and flattening filter (FF) modes.Methods Ten previously treated patients with loco-regionally advanced nasopharyngeal carcinoma were retrospectively included and replanned using FFF and FF VMAT,respectively.Meeting all clinical criteria,the dose-volume histograms (DVH),dose distribution of target volume and organs at risk (OARs),target conformity index (CI),total monitor unites (MUs) and treatment time were compared across the plans.Results VMAT plans suing either FFF and FF modes can meet the clinical objectives.The maximum and mean target dose of FFF VMAT plans were significantly higher than that of FF VMAT plans (t =-0.31,-O.35,P ＜ O.05).Yet the planning target volume (PTV) CI of FF mode was slightly better than of FFF mode (t =5.42,P ＜0.05).The maximum doses of lenses in FFF VMAT plans were lower than that of FF VMAT plans (t =25.87,17.45,P ＜ 0.05),and other OARs displayed no significant difference.The mean total MUs of FFF and FF VMAT plans were (699 ± 16) and (628 ± 12) MUs respectively.The mean treatment time of two modes were consistent (about 2 min).Conclusions The plan qualities of FFF and FF VMAT plans were comparable and both clinically acceptable.The OARs at the edge of radiation field,such as lens,could be spared better using FFF VMAT mode.The total MUs of FFF VMAT plans were higher than FF VMAT plans,yet were delivered within the same time.

As known so far,Sporosarcina pasteurii,or formally termed as Bacillus pasteurii,was considered as one of the most efficient biosystem which is capable of inducing biological mineralization through breaking down urea.Taking advantage of the ‘super power’ of bio-mineralization,Sporosarcina pasteurii has been successfully utilized in application of solidifying sand as a novel biological construction technology,termed as ‘bio-cementation’ Due to the nature of Sporosarcina pasteurii isolated from soil,non-pathogenicity has been observed,it was considered as a very environmentally friendly method.Recently,Sporosarcina pasteurii has been further applied into fields including environmental improvement and biomedicine.However,the mechanism under the strong Sporosarcina pasteurii mediated bio-mineralization is still not well understood.Here,the knowledge and the up-to-date studies about the biological mechanism of Sporosarcina pasteurii mediated bio-mineralization,and the utilization in construction,environment,and biomedicine are reviewed.

Objective To investigate effect of a new lumbar dynamic internal fixation system(DIFS)on the stability and intradiscal pressure of lumbar segment.Methods Eight fresh calf lumbar specimens were collected to build test models,which were loaded with pure moments of 8 N·m in flexion/extension,lateral bending,and rotation planes.The test states included intactness,destabilization,dynamic fixation,semi-rigid fixation,and solid fixation.The data were collected from the third loading cycle to determine range of motion and neutral zone of corresponding segments,and the intradiscal pressure.Results Destabilization significantly increased segmental range of motion and neutral zone in three motion planes without obvious influence on intradiscal pressure.The three fixation systems were all able to stabilize and load destabilizing segments.DIFS restored the range of motion of unstable segment to 77％,60％,61％ and 70％ of the intact level in anterior flexion,posterior extension,lateral bending and rotation planes.Meanwhile,DIFS bore 45％,29％ and 40％ of tbe intradiscal load in lateral bending,rotation and flexion directions,but 100％ of the intradiscal load in back extension.The stability and intradiscal pressure of adjacent segments were not affected by the test states.Conclusion DIFS can effectively restore range of motion of unstable segments and share appropriate intradiscal load in most directions.

Objective To investigate the dose distribution and radiation risk of Varian thoracic cone beam computed tomography (CBCT) with default parameters with reference to Monte Carlo simulation and International Commission on Radiological Protection (ICRP) report 110.Methods EGSnrc/BEAMnrc code was used to simulate the material, thickness, and geometry of the kV CBCT source (kVS) to establish the kVS model.A benchmarked MCSIM code was applied to calculate the dose distribution in the ICRP phantom after the scan with the standard thoracic parameters (110 kV, 20 mA, and 262 mAs), and the conversion coefficient of absolute dose was obtained in a spherical phantom following the TG-61 protocol.The results of Monte Carlo simulation were validated by PDD and Profile in a water phantom and the measurement of the absolute dose in the computed tomography dose index (CTDI) phantom and Alderson phantom.The models including BEIR VⅡ were used to evaluate the radiation risks.Results With reference to the criterion of 3%/1 mm, the uncertainties of PDD and Profile were less than 2%.The difference between the measured and calculated values was<2.9% in the CTDI phantom and ≤0.05 cGy in the Alderson phantom.In the ICRP110 phantom, the doses to the left lung, right lung, left breast, right breast, heart, thyroid, trachea, cancellous bone, and cortical bone were 1.28, 1.39, 1.74, 1.80, 1.46, 0.48, 0.88, 0.85, and 1.84 cGy, respectively.The relative risks of ischemic heart disease, breast cancer, lung cancer, thyroid cancer, and tracheal cancer in a standard scan were1.001 , 1.009, 1.019, 1.000, and 1.008, respectively. Conclusions The accumulated dose and long-term risks of CBCT during image-guided thoracic radiotherapy cannot be neglected and should be effectively controlled.

Objective To evaluate the feasibility and dosimetric features of a volume modulated arc therapy (VMAT)-configured model in knowledge-based optimization of fixed-field dynamic intensitymodulated radiotherapy (IMRT) plans based on the Varian RapidPlan system.Methods ① A dose-volume histogram prediction model was trained with 81 qualified preoperative VMAT plans for rectal cancer and then statistically verified.② For clinically approved 10 IMRT plans with the same dose prescription,the above model was used to automatically generate new optimization parameters and dynamic muhileaf collimator (MLC) sequences with field geometry and beam energy unchanged.③ In order to rule out the disparities between different versions,a single algorithm was used to calculate the absolute doses of the original and new plans.④ Statistical analyses were performed on dosimetric parameters after comparable target dose coverage was achieved in the two plans by appropriate normalization.Results On the basis of similar target dose homogeneity and coverage,RapidPlan significantly reduced the doses to the urinary bladder (D50％ by 9.01 Gy,P =0.000;Dmean by 8.08 Gy,P =0.005) and the femoral head (D50％ by 4.20 Gy,P =0.000;Dmean by 3.84 Gy,P=0.005) but significantly elevated the mean total number of monitor units (1211±99 vs.771±79,P=0.000) and the number of fields with multiple MLC carriage groups.The knowledge-based semi-automated optimization caused a significantly larger number of high-dose hotspots but a similar D2％ (52.54 vs.52.71 Gy,P=0.239).Conclusions The VMAT model can be used for the knowledge-based semi-automated optimization of IMRT plans to enhance the efficiency and OAR protection.However,the resulting high-dose hotspots need further manual intervention.

Objective To explore the Monte Carlo calculation methods for the absolute dose calibration and output factor of 6 MV flattening-filter ( FF) and flattening-filter free ( FFF) photon beams based on TrueBeam accelerator .Methods The BEAMnrc code was used to model the LINAC head of FF and FFF modes.The BEAM_up covers the components from the target to the monitor chamber , and BEAM_down includes the structures beneath the chamber , the dose deposit to the monitor chamber contributed by the incidence electrons and scattered particles from the secondary collimators were calculated respectively .The incidence electron-induced dose at certain depths on the central axis were simulated by means of the DOSXYZnrc code .By means of dose calibration equation , the calibration factor for the standard field (10 cm ×10 cm) and the output factors for various fields (1 cm ×1 cm-40 cm ×40 cm) were computed respectively .Results For the 6 MV FF and FFF beams under the standard 10 cm ×10 cm field, 1 MU equals to 7.747 ×1013 ±3.099 ×1011 and 3.248 ×1013 ±1.624 ×1011 electrons to the target , respectively , which deposited 21.53 and 35.01 cGy to the monitor chamber of the virtual accelerator respectively .The difference between the simulated and calculated output factors were 0.72%±1.4%and 0.56%±0.78%for FF and FFF , respectively .Conclusions The model generated and measured output factors agree well , indicating the good accuracy of the dose calculation by the model , which would provides basis for further clinical dosimetric studies .