Objective To introduce a finger leaf design that is applied to dual layer MLCs.Methods An optimization model was firstly constructed to describe the problem of determining leaf end shapes,and the corresponding problems were then solved by the simplex search method or the simulated annealing technique.Optimal parameters for arc shapes of leaf end projections were obtained,and a comparison was done between optimized MLCs and conventional MLCs in terms of field conformity.The optimization process was based on 634 target fields selected from the patient data base of a treatment planning system.Areas of these fields ranged from 20.0 to 602.7 cm with a mean and its standard deviation of (125.7 ±0.0) cm~2.Results The optimized leaf end shapes projected to the isocenter plane were semicircles.With the finger leaf design,the total area of discrepancy regions between MLC fields and target fields was reduced by 32.3% .Conclusions The finger leaf design improves the conformity of the MLC shaped fields to the desired target fields.

Tissue engineering has always been a hot spot in the life science area over the past few years. However, there are some problems, such as the multiplication of seeding cells, the preparation of tissue engineering scaffolds, and the controlled release of drugs from scaffolds and so on. Recently microspheres have been widely used to solve these problems. For example, microspheres are used as microcarriers to culture seeding cells. In addition, microsphers can be either used to prepare engineering scaffolds or directly used as scaffolds. Microspheres can be used to load drugs and control the drug release as well. In this paper the application of microspheres in tissue engineering is reviewed and the up-to-date methods are introduced, including ways of improving performances of microcarriers, preparing scaffolds with microspheres and adding drug-loaded microspheres into scaffolds.

Objective To compare the relative accuracy of single-plane and biplane area-length methods for determining right ventricular (RV) volume and ejection fraction (RVEF) both in vitro and in vivo studies. Methods The in vitro study consisted of 15 human right ventricular casts and the in vivo study consisted of 45 patients. RV volume by single-plane area-length method was determined by the product of RV area from apical four-chamber view and the distance from RV apex to tricuspid annulus. RV volume by biplane area-length method was defined as 2/3?(the product of RV area from apical four-chamber view and the distance from pulmonary valve to tricuspid valve). The actual volume of RV casts was determined by water displacement method. RV angiography was used to determine RV volumes and RVEF in the in vivo study. Results RV volumes calculated from both single-plane and biplane methods correlated closely with RV cast volumes in the in vitro study (r= 0.87- and 0.91-, respectively; both P 0.05-), but RV volume determined by single-plane method significantly overestimated angiographic volume (P

The response of normal islet β cells to insulin resistance is compensatory insulin hypersecretion in order to maintain normoglycemia. The mechanisms involved in the compensation process including the expansion of β cell mass and enhanced β cell performance via various molecular cascades, signaling pathway sand their interactions have been extensively investigated in recent years.

The study on medical education directly affects the quality of education and cultivation of medical professionals as well as the level of running school.It is very important for the medical colleges to take some measures to solve these problems existing in medical teaching reform and research,such as renewing teachers' ideas,enhancing the standardization of management,increasing the enthusiasm of the teachers etc.

Objective: To prepare an adenovirus, Ad-CD, expressing bacterial cytosine deaminase(CD),and use it for tumor suicide gene therapy. Methods: We constructed a recomb ined adenoviral vector carrying CD or LacZ. 293 packaging cell was trans fected by the newly-constructed plasmid and generated the infectious virus. The n the adenovirus was used to infect C26 cell in vitro. Results: The growth of Ad-CD-infected cell was obviously surpressed after admini stration of 5-FC. Conclusion: CD gene carried by adenoviral vec tor is effective for tumor cell suicide gene therapy in vitro.

Objective To investigate the clinical value and adverse reactions of indwelling ureteral stentsinthepreventionofureteralinjurybeforecomplexpelvictumorsurgery.Methods 145casesofpatients with rectal cancer ,cervical cancer ,ovarian cancer and pelvic sarcomas were retrospectively analyzed ,and 53 pa-tients with complex pelvic tumor surgery ,preoperative were under cystoscope unilateral or bilateral ureteral stent tube,pulled out according to the intraoperative situation after surgery or lien ,92 patients as control group .Results Ureteral injury was found in 10 of the 145 patients,2 cases in ureteral catheter group and 8 cases in control group .3 cases of postoperative ureteral fistula occurred in the control group .Indwelling ureteral stents could cause adverse reactions such as hematuria ,osphyalgia and urinary irritation ,and the adverse reactions of catheter group was obviously higher than that of control group (P<0.05).Conclusion Cystoscopic ureteral stent placement has important clinical significance for prevention of ureteral injury despite certain adverse reactions ,which can be used in operation of complex pelvic tumor .

Objective To use clustering analysis to help physicians detect abnormal parameters in radiotherapy treatment plans and improve the efficiency of plan verification. Methods From 2010 to 2015, 835 breast cancer treatment plans for using 4?field hybrid intensity?modulated radiotherapy from MOSAIQ were collectted. Fractional dose, beam angle, and monitor unit were used as featured parameters of a treatment plan to generate a dataset. The K?means clustering algorithm based on principal component analysis was used to perform a clustering analysis of the dataset and divide the dataset into different clusters. The outliers of clusters were automatically detected based on the distance threshold. The outlier?contained treatment plans were manually verified by physicians to determine the accuracy of clustering analysis in detection of abnormal plans. Results In the clustering analysis, the sample space composed by parameters of treatment plans for breast cancer was divided into 4 clusters, 3 of which had outliers detected. In the targeted treatment plans, 3 plans became outliers because of special target volume and the other 4 plans needed improvement. Conclusions Clustering analysis is effective to help physicians to independently verify treatment plans.

Objective To evaluate the efficacy of 10-day compound allantoin containing quadruple regimen in the treatment of chronic gastritis with Helicobacter pylori (H.pylori) infection,and to compare with the bismuth-containing quadruple therapy.Methods Altogether 173 patients with H.pylori positive chronic gastritis confirmed by gastric endoscope were divided into 10-day compound allantoin containing quadruple regimen group (n =43),24-day compound allantoin containing quadruple regimen group (n =46),10-day bismuth-containing quadruple regimen group (n =42) and 24-day bismuth-containing quadruple regimen group (n =42).After the treatment,the eradication rate of H.pylori,the rate of gastrointestinal symptoms (epigastric pain,bloating and belching) relief and the adverse effects of each group were observed.Intention-to-treat (ITT),per-protocol (PP) statistical analysis and chi-square analysis were performed for statistical analysis.Results H.pylori eradication rates of 10-day compound allantoin containing quadruple regimen group,24-day compound allantoin containing quadruple regimen group,10-day bismuth-containing quadruple regimen group and 24-day bismuth-containing quadruple regimen group analyzed by ITT were 90.7％ (39/43),91.3％ (42/46),90.5％ (38/42) and 88.1％ (37/42),respectively; while analyzed by PP were 90.7％ (39/43),93.3％ (42/45),90.5％ (38/42) and 90.2％ (37/41),respectively.And there were no statistical differences between groups (all P＞0.05).Ten days after the treatment,the rates of epigastric pain relief of 24-day compound allantoin containing quadruple regimen group and 24-day bismuth-containing quadruple regimen group were 81.1％ (30/37) and 78.8％ (26/33),respectively,the rates of bloating relief were 82.4％ (28/34) and 71.0％ (22/31),respectively,and the rates of belching relief were 76.9％ (20/26) and 75.0％ (21/28),respectively.There were no statistical differences between the two groups (all P＞ 0.05).However after 24-day treatment,the rates of epigastric pain relief of 24-day compound allantoin containing quadruple regimen group and 24-day bismuth-containing quadruple regimen group were 91.9 ％ (34/37) and 87.9％ (29/33),respectively,the rates of bloating relief were 94.1％ (32/34) and 87.1％ (27/31),respectively,and the rates of belching relief were 96.2％ (25/26) and 85.7％ (24/28),respectively.There were no statistical differences between the two groups (all P＞0.05).And the rates of epigastric pain and bloating relief increased after 24-day treatment compared with those of 10-day treatment,however the differences were not statistically significant between the two groups (all P＞ 0.05).In 24-day compound allantoin containing quadruple regimen group,the rate of belching relief was higher after 24-day treatment compared with that of 10-day treatment,and the difference was statistically significant (x2=4.127,P=0.042).No severe adverse effects were observed in each group,and there were no adverse effects such as oral metal odor,tongue black and melena in compound allantoin containing quadruple therapy.Conclusions Ten-day compound allantoin containing quadruple therapy as first-line approach in the treatment of chronic gastritis with H.pylori infection can get better H.pylori eradication and the efficacy is similar to bismuth quadruple therapy.Meanwhile the symptom relief rate is high and no obvious adverse effects were found.

Different human thyroid carcinoma cell lines were treated with all-trans retinoic acid(RA). RA could inhibit cell growth,improve iodide uptake and increase some thyroid specific genes and retinoid acid receptor(RAR)mRNA expressions in FTC-133 cells.However,RA had no effect in C643,HTH74 and XTC. UC1 cells.These findings indicate that different thyroid carcinoma cells display diverse responses to RA.