Objective To investigate the dosimetric characteristics and their clinical applications of volumetric modulated Arc therapy (RapidArc) with fixed-fields intensity modulated radiotherapy for early stage nasal NK/T-cell lymphoma.Methods Ten patients with stage Ⅰ E and Ⅱ E nasal NK/T-cell lymphoma were enrolled in the study.Five field coplanar plan (5F),nine field coplanar plan (9F),five field non-coplanar plan (5F-N) and RapidArc plans were designed for each patient,in which 5F plan was set as the control group.Conformity index (CI) and homogeneity index (HI) as well as the maximum dose of organs at risks were compared.Results The target CI of 5F,9F,5F-N and RapidArc plan was 0.419±0.159,0.478 ±0.181,0.465 ±0.121 and 0.518 ±0.111,respectively.Compared with 5F (0.136±0.038),the target HI of 9F and RapidArc plan was 0.111 ±0.027 and 0.112 ±0.031 (t =3.11,3.04,P ＜ 0.05).9F plan significantly increased the Dmax of lens in the contralateral side(t =2.82,P ＜ 0.05) and in ipsilateral side (t =3.25,P ＜ 0.05),while 5F-N plan decreased the Dmax of optical nerves by up to 9％.RapidArc plan effectively reduced the radiation to organs at risk in lens (t =3.25,P ＜0.05),eyes (t =3.25,P ＜0.05),optical nerve (t =2.57,P ＜0.05) and optical chaism(t =7.62,P ＜0.05).The delivery efficiency of four plans ranked as RapidArc ＞ 5F ＞ 5F-N ＞ 9F.Conclusions RapidArc produced statistically significant improvement in the dose distributions of targets,and also reduced the Dmax of organs at risk,which would be the better choice of radiotherapy for nasal NK/T-cell lymphoma.

BACKGROUND:Currently, there are many studies on colapsed repair, but a systematic and horizontal comparison is not reported yet. OBJECTIVE: To compare the effect of conventional resin adhesive, resin adhesive+silane coupling agent and adjacent surface open part of the crown on colapsed repair through clinical trial and in vitro experiment. METHODS: (1) Clinical trial: 90 patients with porcelain colapse were randomized into three groups, and respectively treated with conventional resin adhesive, resin adhesive+silane coupling agent and adjacent surface open part of the crown. Success rate was measured and compared among three groups at 1 year after repair. (2) In vitro test: Twenty test specimens were equaly divided into two groups, and treated with conventional resin adhesive and resin adhesive+silane coupling agent, respectively. Then, shear strength was detected in the two groups. Twenty double-crown specimens were equaly divided into four groups. The first three groups were treated with sand blasting, silane coupling agent and their combination treatment, respectively; the rest group had no treatment (control group). After repair, the tensile strength of each specimen was detected.RESULTS AND CONCLUSION:The success rate of colapsed repair was 37% for conventional resin adhesive, 90% for resin adhesive+silane coupling agent and 100% for adjacent surface open part of the crown. The shear strength was (13.978±0.343) MPa for the conventional resin adhesive and (10.058±0.64) MPa for resin adhesive+silane coupling agent, and there was a significant difference between two methods (P < 0.01). The tensile strength was (0.68±0.04) kN in the control group, (1.00±0.02) kN in the sand blasting group, (1.31±0.08) kN in silane coupling agent group, and (1.09±0.04) kN in the combination group, and there was a significant differences between groups (P < 0.01). Experimental results show that the silane coupling agent+resin adhesive treatment and adjacent surface open part of the crown are superior to conventional resin adhesive.

Objective To carry out hand hygiene(HH) quality control circle(QCC) activity by using WeChat group, improve HH compliance of health care workers(HCWs), and enhance the circle members' ability to solve problems.Methods In June 2015, 11 healthcare-associated infection control professionals in a hospital created HH WeChat group by using cellphones, activity cycle was once every two weeks, professionals analyzed the existing problems, and formulated countermeasures as well as implemented methods by group chat form, circle members introduced and implemented strategies to HCWs in their departments, so as to achieve the implementation effect.Results After the creating of WeChat QCC, HCWs' HH compliance increased from 56.71% before activity to 85.94% after activity, difference was statistically significant (X2=61.928, P<0.05);QCC members' responsibility, self-confidence, enthusiasm, harmony degree, team cohesiveness, quality control technique, communication, coordination, and problem-solving skill were all significantly improved.Conclusion Application of WeChat QCC activity can improve HH compliance of HCWs and the ability of circle members.

Objectives:Using IE 1 gene promoter of Autograph californica nuclear polyhedrosis virus(AcNPV),a transfer vector with an immediately early gene promoter was constructed.　Methods:Transfer vector pAcPIneo which contains neomycin resistance gene(neo)coding sequence downstream of IE 1-promoter was constructed and cotransfected with the wild type of AcNPV DNA into Sf9 insect cells.Recombinant virus was selected by G418 resistance since the neo gene can be expressed in Sf9 cells.　Results:Northern blot hybridzation with 32　P labeled neo gene fragement as probe showed that the neogene was integrated in plogene of AcNPV genome.　Conclusions:Transfer vector with an immediately early gene promoter of baculovirus was constructed successfully,the neo gene was transcribed from the immediately early phase to the very late phase in infected cells.

ObjectiveTo investigate the strategy and effect of microsurgical treatment for pediatric cerebellar astrocytoma. Methods93 cases of pediatric cerebellar astrocytoma were reviewed who received microsurgical operation. ResultsTotal removal was achieved in 85 cases while subtotal in 8 cases. Pre-operatively, tumor capsule puncture was performed in 21 cases, lateral ventricle puncture and draining in 9 cases and ventricle-peritoneal shunt in 23 cases. Post-operative radiotherapy was performed in 8 cases. They were followed up for 26 months to 5 years with 8 cases lost. There was no death and recurrence. Scores of Karnofsky Performance Status (KPS) was more than 90 in all cases followed up. ConclusionPediatric cerebellar astrocytoma can be treated satisfactorily with microsurgery. By improving surgical removal rate, reasonable peri-operative treatment and early rehabilitation, children with cerebellar astrocytoma can achieve long and excellent living status.

Objective To evaluate the accuracy of image registration based on bony structure (RBS) and grey-scale (RGS) in positioning correction of radiation treatment,and their reliability in clinical application.Methods Setup errors of anthropomorphic phantom (chest& abdomen,head& neck) were simulated with x-,y-,z-directions.CBCT images were acquired for each simulation and registered with planning CT.using bony structure and grey-scale registration separately.Geometry accuracy of all registration were then obtained and analyzed.Results The errors of RBS and RGS in x-,y-,z-directions were (-0.65 ±0.22) mm and (-0.70±0.17) mm (P=0.00),(1.02 ±0.27) mm and (0.90±0.20) mm (P =0.00),(1.46 ± 0.53) mm and (1.47 ± 0.47) mm (P =0.54) for head& neck positioning; with (0.82±0.33) mm and (0.79±0.18) mm (P=0.03),(2.45±1.17) mm and (1.61 ±0.84) mm (P =0.00),(1.44 ± 3.25) mm and (0.19 ± 1.11) mm (P =0.00) for chest& abdomen positioning.Conclusions RGS is more accurate and stable than RBS.The accuracy of image registration is a little better for head& neck than that for chest& abdomen.The algorithms of image registration used in clinical application needs to be tested independently and the systematic error needs to be corrected before applying in different treatment techniques according to their accuracy requirement.

AIM: To study the cytoprotective role of NaNO_2 preconditioning against H_2O_2 induced damage in PC12 cells. METHODS: PC12 cells were treated with different concentrations of NaNO_2 for 6 h, 12 h, 24 h and 48 h, respectively. The viability of the cells was measured by MTT method and cell counting. The apoptotic rate of PC12 was determined by Hoechst 33258 staining to calculate the ratio of the cells between concentrated and broken nucleus in the total cell count. PC12 cells were pretreated with NaNO_2 at concentration of 3 mmol/L for 24 h. The cytoprotective role to the toxicity of H_2O_2 at concentration of 1.1 mmol/L for 6 h was observed by MTT. The cell apoptosis was measured by flow cytometry and staining with Hoechst 33258 and PI. The activities of catalase (CAT), superoxide dismutase (SOD), and the changes of glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured by the method of colorimetry. RESULTS: The dose-response results showed that the effect of NaNO_2 on PC12 cell proliferation was a typical β-shape curve. The maximal stimulatory response was at 24 h, and the concentration of the maximum stimulatory response was 1.4 mmol/L. The maximal stimulation of the concentration-responses was 156% above the control. No observable adverse effect level (NOAEL) was 6 mmol/L. IC_(50) was 45 mmol/L. When the cells were pretreated by NaNO_2 at concentration of 3 mmol/L for 24 h, and then exposed to H_2O_2 at concentration of 1.1 mmol/L for 6 h, the proliferation rate was increased as compared to the cells treated with H_2O_2 alone. Under the conditions of treating the cells with NaNO_2 at concentration of 3 mmol/L to induce the adaptive response, then exposing the cells to H_2O_2 at concentration of 1.1 mmol/L, the apoptosis rate in non-preconditioning group was 44.9%, the apoptosis rate in preconditioning group was 19.1%, the difference was significant (P<0.05). The cytoprotective effect of NaNO_2 was inhibited by nitric oxide (NO) scavenger ferrohemoglobin. The activities of SOD, CAT and the level of GSH-Px were markedly increased, the content of MDA decreased in preconditioning group. CONCLUSION: Exposure of NaNO_2 at concentration of <6 mmol/L induces hormesis on PC12 cells. Low dose of nitrite plays an important role in cytoprotection by reducing nitrite to NO, indicating that decrease in lipid peroxidation and increase in endogenous antioxidants may play a key role in cytoprotection induced by preconditioning with low dose of NaNO_2 in PC12 cells.

This study is to investigate the cytoprotective role of NaNO2 preconditioning against ethanol induced damage in human hepatoma SMMC-7721 cells. The cells were preconditioned with NaNO2 (0.25 mmol x L(-1)) for 24 hours or 4 weeks, and then exposed to ethanol (200 mmol x L(-1)) for additional 12 h and untreated cells served as control. Both temporal and chronic NaNO2 preconditioning could prevent ethanol elicited cytotoxicity as evidenced by thiazolyl blue (MTT). NaNO2 preconditioning also could inhibit ethanol-induced apoptosis, which was confirmed by FITC-Annexin V/PI flow cytometer and Hoechst 33258 and PI staining. Further, simultaneous NaNO2 preconditioning treatment along with ethanol showed protection against ethanol mediated cellular damage as indicated by significantly decreased levels of malondialdehyde (MDA) and elevated activities of superoxide dismutase (SOD) and catalase (CAT). Western blotting analysis revealed that in ethanol treated cells preconditioned with NaNO2, the HIF-1alpha and Bcl-2 increased obviously, while the expression of pro-apoptotic proteins, including Bax, Caspase-9, Caspase-3 decreased. The results showed that low doses of NaNO2 preconditioning resistant to ethanol-induced human hepatoma SMMC-7721 cells apoptosis, which mechanism may be related to increased expression of HIF-1alpha in the cells.

Objective To study the baseline level of fraction anisotropy (FA) and the normal value of apparent diffusion coefficient (ADC) in deep white matter of preterm and its application.Methods From Oct.2010 to Dec.2013,in Department of Neonatology,Jiangsu Province Hospital,magnetic resonance imaging (MRI) (T1,T2) and diffusion tensor imaging (DTI) were done on 13 preterm infants of less than 37 weeks of corrected gestational age (CA),42 preterm infants of term-matched age,and 15 term infants.ADC and FA were measured in genu and splenium of corpus callosum (CC),anterior limb and posterior limb of internal capsule (IC).Results 1.The ADC values in genu,splenium,anterior limb of right IC,posterior limb of right IC,anterior limb of left IC,posterior limb of left IC in CA ＜ 37 weeks infants were higher than those in term-matched infants and in term infants.The ADC values in the 6 regions in term-matched infants and in term infants were significantly different with those in CA ＜ 37 weeks infant(F =5.559,5.775,21.948,19.462,30.586,15.452,all P ＜ 0.01).The differences of ADC values between CA ＜ 37 weeks infants and term-matched infants,between CA ＜37 weeks infants and term infants were significant(all P ＜0.05),except that in CC between CA ＜ 37 weeks infants and term-matched infants.2 The FA values in genu,splenium,anterior limb of right IC,posterior limb of right IC,anterior limb of left IC,posterior limb of left IC in CA ＜ 37 weeks infants were lower than those in term-matched infants and in term infants.The FA values in the 6 regions in term-matched infants and in term infants were significantly different from those in CA ＜ 37 weeks infants (F =9.835,7.500,4.811,11.430,8.674,12.666,all P ＜ 0.01).The differences of FA values between CA ＜ 37 weeks infants and term-matched infants (P ＜ 0.05),between CA ＜ 37 weeks infants and term infants were significant (all P ＜ 0.05).Conclusions The baseline values of FA and ADC in different deep white matters were obtained.As corrected gestational age of preterm babies' increased,FA values in brain white matter increased,while ADC values decreased.The myelination in most white matter of preterm infants at matched term can catch up with that of term infants.The diagnostic value of ADC and FA needs to be studied further.

Objective To study the mathematical predicting model of parotid DVH for the NPC IMRT planning, and its accuracy with the analysis of medical data. Methods 50 NPC radiotherapy treatment plans with same beam setup were chosen as sample data set, then their parotid DVHs and distance of voxels in the parotid to the target volumes were calculated with self-developed program to form the distance to target histogram ( DTHs);principal component analysis was applied to DVHs and DTHs to acquire their principal components ( PCs) ,and then nonlinear multiple variable regression was used to model correlation between the DTHs' PCs, parotids volume, PTVs and the DVHs. Another 10 plans were chosen as test data set to evaluate the efficacy and accuracy of the final model by comparing the DVHs calculated from our model with those calculated from the TPS. Results Up to 97% information of DTHs and DVHs can be represented with 2 to 3 components, the average fitting error of sample data set was (0±3. 5)%;in the 10 test cases, the shapes of DVH curves calculated from predicting model was highly the same with those from the TPS, the average modeling error was (-0.7± 4. 4)%,the accuracy of prediction was up 95%. Conclusions Our developed model can be used as a quality evaluating tool to predict and assure the dose distribution in parotid of NPC radiotherapy treatment planning effectively and accurately.