Generally,pencil beam kernels for photon beam calculation are obtained through Monte Carlo calculations.In this paper,a pencil beam model is set up with a method of deconvolution from measured broad beam profiles.These profiles are usually available in a radiotherapy planning system.Furthermore,this method is applied to computing dose distributions at different sizes.Comparisons with measurements show that the accuracy of the calculated dose distributions fits well in a1%error interval in high dose gradient regions.

Objective To evaluate the monitoring value of serum albumin and plasma von willebrand factor in patients with stroke.Methods Serum albumin and plasma von willebrand factor were measured from 145 patients with stroke(95 patients with nonpoor outcome and 50 patients with poor outcome) in two weeks and after six months from stroke onset to study the relationships with prognosis.Results Serum albumin level was significantly higher in patients with nonpoor outcome(mRS≤2) after six months stroke onset than those with poor outcome(mRS≥3) and was lower after six months stroke onset than in two weeks from stroke onset.On the other hand,plasma vWF level in patients with stroke was significantly higher than that in healthy controls and was higher in two weeks than after six months from stroke onset.Patients with poor outcome had higher plasma vWF level than patients with nonpoor outcome in two weeks and after six months from stroke onset,but had no significant difference.Conclusion The level of serum albumin and plasma von willebrand factor is related with nutritional status,active extent and prognosis in patients with stroke.

Objective To find a method for calculating the scatter dose of irregular fields. Methods The original Day function was improved to vary with radiation depth, and the improved Day function was used for irregular fields to calculate scatter dose. Results The accuracy was greatly improved by making Day function depend on radiation depth, and the error was within 1.5%. Conclusion This method can be used to calculate the scatter dose of irregular fields as well as rectangular fields.

Objective To evaluate the feasibility,efficacy,and short to mid-term results of endovascular management of acute type B aortic dissection complicating visceral or lower limb malperfusion.Methods A retrospective study was conducted in 23 consecutive patients with acute type B dissection complicating visceral or lower limb malperfusion treated endovascularly at a single center between July 2001 to December 2012.Of the 23 patients identified [20 men,3 women; mean age (52 ±9) ranging 42-75]presented with clinical and imaging evidence of end-organ malperfusion:renal artary in 5 (21.7％),superior mesenteric artery in 9 (39.1％),celiac trunk in 3 (13％) and lower limb in 6 (20.1％),artary renal and lower limb in 2.Results All patients had stent-graft coverage of the proximal entry tear.11 (47.8％) patients needed additional branch vessel stenting.Successful correction of malperfusion was achieved in all the patients and the successful rate of operation and technology was 100％.In 1 patient,ischemia in the lower limb was resolved after a stent was implanted to the right iliac artery.In another patient,complicated with lower limb ischemic necrosis,amputation was performed after one stage stent-graft placement.The duration of follow-up was 6 months to 72 months,mean (21 ± 11)months.There was no migration of stent-graft and end-organ ischemia.No patients suffered from paraplegia in this group.Conclusions Endovascular coverage of the proximal entry tear in acute type B aortic dissections complicating end-organ malperfusion is a reasonable first line treatment.But some cases may need a combination branch vessel stenting.

Objective To evaluate femoral artery ligation for femoral artery pseudoaneurysm secondary to drug injection. Methods Clinical data of 32 drug addicts of femoral artery pseudoaneursysm caused by drug injection undergoing femoral artery ligation and local debridement were reviewed retrospectively.The blood supply of affected limb was evaluated by oxygen saturation of distal limb and its function.All the cases were followed up at 3,6,9,and 12months after the operation. Results Surgery was successful in all cases. There were no significantly difference of the limb oxygen saturation between postoperative and preoperative period (95.1％ ± 2.8％ vs.96.9％ ± 1.9％ ; t =1.26,P =0.25 ).White blood cells and neutrophils percentage significantly decreased after surgery.All patients were followed up for 1 year.Lower extremity ischemia after 6 hours of operation in one case treated by autologous saphenous vein bypass recovered. On 3 months mild claudication was observed in 5 cases. On 6 months claudication remained in only 2 cases,which disappeared on 9 months.All patients were able to maintain normal life.Conclusions Femoral artery ligation is a safe, effective and simple treatment modality for femoral pseudoaneurysms secondary to drug injection.

short peptide AS1 screened from the phage random peptide library of 12 amino acids has antigenicity and can react with sera of AS patients. These findings indicate that AS1 could be one of candidate molecules of AS-specific serum markers.

Objective:To study the efficacy and drug-related adverse reactions of long-term appli-cation of biological anti-rheumatic drugs (bDMARDs) to patients with ankylosing spondylitis (AS), and provide reference for clinical diagnosis and treatment.Methods:We retrospectively analyzed the clinical data of AS patients who were followed-up for more than 5 years in the Department of Rheumatology and Immunology of Peking University Shenzhen Hospital. The patients treated with bDMARDs alone or combined with traditional antirheumatic drugs were included as the treatment group, while those who did not receive biological or non-biological antirheumatic therapy were included as the control group. The data collected included clinical sym-ptoms, inflammatory biomarkers, imaging results, drug applications and drug-related adverse reactions, etc. The counting data were tested by χ2 test, the measurement data in normal distribution was tested by t test, and the measurement data that not normally distributed was tested by Mann-Whitney U test. Paired test was used for statistical processing before and after treatment. Results:We collected the data of 114 eligible patients, including 64 in the treatment group and 50 in the control group. There were no significant differences in baseline data between the 2 groups, including mean follow-up time, course of disease, age, sex ratio, HLA-B27 positive rate, morning stiffness duration, night pain, peripheral arthritis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and imaging. After 5 years, patients in the treatment group had shorter morning stiffness [(3±7) min vs (26±37) min, t=4.827, P<0.01], lower nighttime pain rates [(3/64, 4.8%) vs (29/50,58.0%), χ2=38.329, P<0.01], lower ESR level [(14±14) mm/1 h vs (20±18) mm/1 h, t=2.102, P=0.038], lower CRP level [(7±8) mg/L vs (14±19) mg/L, t=2.431, P=0.017], and lower progression rate of sacroiliac arthritis [(18/64, 28.1%) vs (35/50, 70.0%), χ2=19.786, P<0.01], than the control group. The main drug-related adverse reactions in the treatment groupincluded reversible leucopenia, elevated transaminase level, redness and swelling at the injection site. Conclusion:Biologics treatment for more than 3 consecutive years can effectively control the clinical symptoms of most AS patients, reduce inflammatory indicators and delay the imaging progression of the sacroiliac joint. Without treatment, the imaging progress of the sacroiliac joint in AS patients could be 70% after 5 years.

Extracellular matrix (ECM)is not only one of current hot-points in medical cell biology,but also one tricky part for undergraduates to learn. This article compared chapters of ECM in medical cell biology courses and spotlighted that ECM chapter was often neglected in some domes-tic universities. Then it analyzed the possible causes,such as variable arrangement of ECM section in current textbooks. Lastly,the article recommended several suggestions,including giving a timely re-vision of the old ECM knowledge,designing an appropriate strategy for teaching,enumerating certain representative diseases to improve the ECM education. It appealed our teachers to pay more attention to how to make the module of ECM master well in near future.

Objective:To study the relationship between different pulse forces and cyclical power(CP)of radial artery motion.Methods:39 patients’and 20 healthy persons’ ECG and pressure sphygmograms were collected synchronously with NX-1 sphygmograph.On the basis of automatic detecting R waves of ECG and FFT analysis of pressure sphygmograms with SPTool of MATLAB 7.0.1,change in frequency domain of radial artery motion with different forces was observed and CP was worked out.Results: There is signifi cant deviation between CP of pulse tracings with different forces(pulse tracings with powerful force〉pulse tracings with normal force〉pulse tracings with weak force).Conclusion: CP of radial artery motion can be used to discriminate pulse force.

Objective To discuss the significance of region Ⅵ lymph nodes dissection in treatment of patients with clinical cervical nodes negative(cN0)papillary thyroid carcinoma(PTC).Methods Clinical data of 38 cases of cN0 PTC treated with region Ⅵ lymph nodes dissection were retrospectively analyzed.The related literature was reviewed.The cervical nodes dissection scope and the key operation points in treatment of cN0 PTC were discussed.Results No permanent recurrent laryngeal nerve injury or parathyroid damage happened.14 cases(36.84％)had occult lymph node metastasis to region Ⅵ lymph nodes.After more than 5 years of follow-up,all the cases had excellent life quality.3 cases(7.89％)were found lymph node metastasis to lateral cervical region and they were given functional neck dissection.No recurrence or metastasis occurred to the 3 cases during more than 2 years of follow-up.Conclusion Region Ⅵ lymph node dissection in treatment of cN0 PTC is safe,reliable,and with less complications.