Objective To explore the dosimetric difference between different radiotherapy technologies in the treatment of early peripheral stage non?small ?cell lung cancer ( NSCLC ) . Methods Four?dimensional computed tomography scans and delineation of target volumes and organs at risk ( OARs) were performed in 5 patients pathologically diagnosed with stage T1/T2 peripheral NSCLC who were admitted from 2014 to 2015. Target volumes contained gross tumor volume (GTV), internal target volume (ITV), and planning target volume (PTV). ITV was contoured on the maximum intensity projection images. PTV was defined as ITV plus a 5 mm margin. OARs contained the heart, lung, esophagus, and spinal cord. The Monaco 5. 0 treatment planning system was used to design three plans. The three?dimensional conformal radiotherapy (3DCRT) plan had 11 fields in the diseased lung covering the PTV plus a 0. 2 cm margin. The sliding window intensity?modulated radiotherapy ( SW?IMRT ) plan had 9 fields in the same areas as the 3DCRT plan. The volumetric modulated arc therapy ( VMAT) plan had the gantry rotating 180° around the diseased lung. The evaluation criteria referred to the RTOG 0618 trial. Comparison was made by paired t test. Results The SW?IMRT plan had a significantly better homogeneity index than the 3DCRT plan ( 1. 03 vs. 1. 24,P= 0. 017 ) . Compared with the VMAT plan, the mean monitor units in the 3DCRT plan was significantly reduced by 24. 5%( P=0. 022) . The V30 and V40 of the 3DCRT plan were significantly reduced by 29. 4% and 28. 4%, respectively, compared with the SW?IMRT plan ( P=0. 003,0. 006) and 56. 7%and 59. 7%, respectively, compared with the VMAT plan ( P=0. 041,0. 019) . Conclusions 3DCRT may be an appropriate radiotherapy method for early stage NSCLC.

A century ago the Flexner Report facilitated the process of modern medical education reform.Half a century ago,Problem-based learning initiated the student-centered medical education model.At present training medical students' competency will usher in the third reform in medical education.Over 100 years' development and in the global context of current medical education reform,China's medical education has become an important part of the world medical education.Harbin Medical University conducted an all-around reform through international cooperation and received the accreditation referenced according to global standards in medical education,which is an epitome of the medical education reform in China.

Objective To compare the dosimetric effects of systematic MLC leaf position errors on flattening filter (FF) and flattening filter-free (FFF) IMRT for nasopharyngeal carcinoma (NPC).Methods In totaly of ten patients with NPC were enrolled in the current study.FF IMRT and FFF IMRT plans were designed for each patient, and in-house software was developed to modify the corresponding MLC files.Briefly, three kinds of systematic MLC error presented with 0.5 and 1 mm magnitudes error were simulated.The modified MLC files were re-imported into IMRT plans for dose recalculation, and differences in the dosimetry trends between FF-IMRT and FFF-IMRT plans were analyzed using a dosevolume histogram.Results Upon closed MLC, the average changes in D95％ of PTV and D of parotid glands in FFF-IMRT plans were more sensitive than in FF-IMRT plans (t =3.298-4.793, P ＜ 0.05).Otherwise, when MLC are shifted in the same direction, changes in D95％of PTV, D of PGTV, PTV as well as D of left parotid gland in FFF-IMRT plans were also more sensitive (t =2.372-6.844, P ＜ 0.05), whereas average changes in D of right parotid gland presented with less sensitivity (t =-4.049,-3.378, P ＜ 0.05).Conclusions For out-of-field or large organs, FFF-IMRT plans are more sensitive to leaf position error than FF-IMRT plans.

The prevalence of type 2 diabetes mellitus(T2DM)in China is about 9.1%.Compared with healthy adults, life expectancy for patients with T2DM at 60 years of age can be cut short by 7.3-9.5 years and time for a good quality of life by 11.1-13.8 years.It is important for elderly patients with T2DM to stay functionally active.Frailty, as a common geriatric syndrome, is an important factor affecting the functional status of the elderly, a strong predictor for disability, death and hospitalization, and also a strong predictor for adverse health outcomes in elderly patients with T2DM.This article reviews the relationship between frailty/sarcopenia and T2DM, and the management and treatment of elderly T2DM patients with frailty/sarcopenia.

Aim To investigate the effects of dopamine(DA)on insulin secretion from rat islets and the possible mechanism.Methods Pancreatic islets were obtained from the pancreatic of male SD rats by collagenase P digestion and histopaque-1077 density gradient separation.Insulin secretion experiment was used to observe the change of insulin release after DA treatments.As to study the potential mechanisms of the effects of DA,patch-clamp experiment and calcuim image technique were applied to test the depolarization-evoked Ca2+ currents,action potential duration and intracellular Ca2+ concentration.Results In 2.8 mmol·L-1 glucose,DA had no effect on insulin secretion;in 16.7 mmol·L-1 glucose,dopamine inhibited insulin secretion in a dose-dependent manner.DA inhibited the inward calcium current,shorten the action potential duration,and reduced the intracellular Ca2+ concentration.Conclusion DA inhibits insulin secretion maybe by decreasing the inward calcium current leading to shorten the action potential duration and reduce the intracellular Ca2+ concentration.

Objective To analysis the effect of conbercept ophthalmic injection on peripheral blood vascular endothelial growth factor,intraocular pressure and visual acuity in patients with age related macular degeneration.Methods 60 patients who were diagnosed with age related macular degeneration were collected.All patients were randomly divided into experimental group and control group,30 cases in each group, lucentis intravitreal injection was given into the vitreous cavity in control group, experimental group give conbercept injection into the vitreous cavity,once a month.All patients were treated for 3 months,after the end of treatment,all patients serum VEGF and CRP,CMT,CNV and fluorescence leakage rate,intraocular pressure and visual acuity were detected.ResuIts After treatment,compared with control group,the content of serum VEGF was significantly lower in the experimental group(P<0.05).The content of serum CRP was significantly lower in experimental group(P<0.05).The CMT,CNV and fluorescence leakage rate were significantly lower in the experimental group (P<0.05).The level of IOP and visual acuity(logMAR)were significantly lower in the experimental group (P<0.05).ConcIusions Conbercept ophthalmic injection can reduce age-related macular degeneration patients week blood VEGF and CRP levels and decrease the CMT, CNV and fluorescence leakage rate, reduce intraocular pressure, visual acuity improvement and have guiding significance for clinic.

The hybrid pencil beam model (HPBM) is an effective algorithm for calculating electron dose distribution in radiotherapy. The mean energy distribution of incident electron beam in phantom is one of the factors that affect the calculation accuracy of HPBM, especially in field edge areas near the end of the electron range. A new fitted formula based on Monte Carlo (MC) simulation data for electron beams with energy range of 6-20 MeV in the homogeneous water phantom is proposed in this paper. The precision of the fitted formula within the scope of the energy was evaluated by comparing the electron dose distribution of ECWG measured data with that obtained from HPBM which took the mean electron energy that calculated by the fitted formula and the existed empirical formula, respectively. The results showed that the accuracy of dose distribution that obtained by the mean electron energy calculated with the fitted formula increased about 1%.
Algorithms ; Electrons ; Humans ; Monte Carlo Method ; Phantoms, Imaging ; Radiotherapy Planning, Computer-Assisted ; Water

Objective To investigate the changes of thyroid autoantibody(TAA)in children with Turner syndrome(TS),and its association between TAA and thyroid dysfunction,age,karyotype and dyslipidaemia.Methods Thirty-two patients with TS diagnosed by chromosome analysis hospitalized at Sun Yat-Sen Memorial Hospital,Sun Yat-Sen University from July 2007 to July 2015 were divided into 2 groups based on TAA-positive or TAA-negative,then the thyroid dysfunction,the age,the karyotype and the lipid metabolism were compared between 2 groups.Results Of the 23 cases of TAA-positive girls(23/32 cases,71.88％),9 girls(39.13％)suffered from thyroid dysfunction;of the 9 cases of TAA-negative girls(9/32 cases,28.12％),3 girls(33.33％)had thyroid dysfunction.As compared with the girls in TAA-negative group,the age in TAA-positive group was significantly higher[(12.08±2.90)years old vs.(8.89±4.17)years old],and the difference was significant(t=101.500,P=0.047).The patients were divided into 4 age groups:0-5 years old,>5-10 years old,>10-15 years old and >15 years old;the rates with TAA-positive were 25.00％(1/4 cases),75.00％(6/8 cases),82.35％(14/17 cases)and 66.67％(2/3 cases)respectively.Twenty patients received the lipid metabolism test,and 11 cases(11/20 cases,55.00％)of them suffered from dyslipidaemia,9 cases of them were TAA-positive(9/11 cases,81.82％),and 2 cases were TAA-negative(2/11 cases,18.18％).The differences in the prevalence of dyslipidaemia between the 2 groups were significant(x2=4.848,P=0.028).There was no significant difference in the numbers of TAA-positive cases among different karyotypes(x2 =4.246,P=0.120).Conclusions Patients with TS are prone to suffer from thyroid dysfunction and dyslipidaemia.Timely detection of TAA and thyroid function is recommended,as well as the lipid metabolism if necessary.

There is a very complicated electrolytical environment in oral cavity with plenty of microorganisms existing there. Various forms of corrosion would develop when metallic prosthesis functions in mouth. One important corrosive form is microbial corrosion. The metabolic products, including organic acid and inorganic acid, will affect the pH of the surface or interface of metallic prosthesis and make a change in composition of the medium, thus influencing the electron-chemical reaction and promoting the development of corrosion. The problem of develpoment of microbial corrosion on dental alloy in the oral environment lies in the primary condition that the bacteria adhere to the surface of alloy and form a relatively independent environment that promotes corrosion.
Corrosion ; Dental Alloys ; chemistry ; Humans ; Mouth ; microbiology ; Saliva ; microbiology ; Surface Properties

Objective To investigate the mechanism of restenosis after carotid stent and balloon angioplasty for the Guangxi swines by intravascular ultrasound(IVUS). Methods Twelve Guangxi swines fed by a high cholesterol diet were randomly divided into two groups. Seven stents were implanted in the left carotid artery of six swines in the first group, and balloon angioplasty was performed in the left carotid artery of swines in the other group. Digital subtraction angiography(DSA) and IVUS were conducted respectively before and after the intervention and in the 13th week. Results IVUS found that the percentage of area stenosis in stent group was (18.31±7.79) % and in balloon group (37.28±7.89) % in the 13th week. The percentage of area restenosis in stent was obviously related to neointimal hyperplasia (r = 0.897, P<0.05), the percentage of area restenosis due to balloon angioplasty was markedly related to area decrease of external elastic lamina (r = 0.856, P<0.05). Conclusions The restenosis in stent was related to intimal hyperplasia of blood vessel,and restenosis after balloon angioplasty had some connection with area decrease of external elastic lamina.