Objective Nonparametric maximum likelihood estimate(NPMLE)and Breslow-Fleming-Harrington estimate(BFH)are extremely sensitive to small risk set for left truncated and right censored data,this study aims to develop estimation methods to improve the estimation accuracy and compare the existing methods.Methods We introduced the NPMLE,weighted NPMLE,conditional NPMLE,BFH and a new weighted BFH estimate.Simulation studies were carried out to compare five methods via the integrated absolute error(IAE) and integrated average width(IAW).Results The IAE of NPMLE,BFH,weighted NPMLE,weighted BFH and conditional NPMLE is ascending in turn;The IAW of weighted BFH is the lowest and NPMLE is the largest,BFH,conditional NPMLE and weighted NPMLE is reversed under different censored rate.Conclusion According to the results of simulation and example,weighted BFH and weighted NPMLE is recommended in turn when the risk set is small.Otherwise,the results of five methods would be consistent.

Objective To construct and identify the screening vector pUC18-EGFP,using EGFP as an indicator. Methods The EGFP gene was prepared by PCR and cloned into pUC18 resulting the vector pUC18-EGFP. Then DNA fragment was inserted into the MCS of pUC18-EGFP to test its practicability based on green fluorescence. Results The pUC18-EGFP was confirmed correctly by restriction enzyme analyses. The pUC18-EGFP was used to select recombinants. The green strains on the plate were confirmed by restriction enzyme and DNA analyses,which were E.coli harboring recombinants. Conclusion The screening vector PUCl8-EGFP was constructed successfully. Thus,we can select the positive clones on plates based on the green fluorescence of EGFP.

AIM: To establish a method for determination of astragloside Ⅳ in Danqi Injection (Radix Salviae Miltiorrhizae,Radix Astragali). METHODS:HPLC-ELSD with Hypersil C_(18) column was used.The mobile phase was composed of acetonitrile-water(38∶62).The flow rate was 0.85 mL?min~(-1).An evaporative light-scattering detector(ELSD) model 2000 was used as detector. RESULTS:For astragloside Ⅳ,the linear range was 1.074-(3.408 ?g),and the average recovery was 100.71%,RSD was 1.79%. CONCLUSION:The method is simple,accurate,reproducible and can be applied to the quality control of the preparation. anqi

Objective To study the feasibility of using silk fibroin/calcium phosphate cement (SF/CPC) as an injectable bone augmentation filling material for defected vertebrae in a sheep model.Methods Bone defects were created on L3,L4 and L5 in 24 adult sheep through the lateral retroperitoneum approach.CPC,SF/CPC,and polymethylmethacrylate (PMMA) were injected into the defects of 3 vertebrae randomly.Twelve sheep were sacrificed at 1 and 6 months postoperation,respectively.Un-decalcified sections were made from the specimens from any 4 sheep and stained with Van-Gieson method.The microcosmic changes of bone-material interface were observed,and the amounts of new bone formation and cement residue were evaluated by histomorphometric analysis.Biomechanical testing was performed on the specimens from the other 8 sheep,in which the strength and stiffness were determined on the vertebrae with L6 as a control.Results Histologically,CPC and SF/CPC contacted the bone directly but the absorption and bone formation were superficial at one month postoperation.At 6 months postoperation,the absorption and bone formation were limited on the surface of CPC while the absorption and bone ingrowth were accelerated in SF/CPC group.In PMMA group where no significant changes were observed between 1 and 6 months,the material contacted the bone loosely,with membrane structure at partial interface but no new bone formation on the material.Histological quantitative analysis showed that new bone formation was significantly more and cement residue significantly less in SF/CPC group than in CPC group at 6 months (P ＜0.05).Biomechanical testing showed that the compressive strength and stiffness were significantly enhanced at 6 months compared with one month in CPC and SF/CPC groups but significantly decreased in PMMA group (P ＜ 0.05).At the 2 time points,SF/CPC,PMMA and intact groups showed equivalent compressive strength and stiffness(P ＞ 0.05).Conclusions The SF/CPC composite has advantages of satisfactory bioactivity and osteoconduction,and relatively faster cement degradation and bone formation during which biomechanical function of vertebrae can be maintained.Therefore it may become a new kind of vertebral augmentation filling material to replace PMMA.

Objective: Lymph node metastasis (LNM) often occurs in cN0 papillary thyroid microcarcinoma (PTMC). The risk factors for lymph node metastasis, especially for high-volume metastasis, were investigated in this study. Methods: The medical records of 1,268 consecutive PTMC patients admitted in the Peking Union Medical College Hospital from 2013 to 2014 were reviewed. Their clinical and pathological features were collected. Univariate and multivariate analyses were performed to identify the risk factors for LNM/highvolume LNM. Results: Of the 1,268 patients, 416 patients (32.8％) and 43 (3.4％) had LNM and high-volume LNM, respectively. According to the univariate analysis results for the risk factors of LNM, male (42.22％ vs. 30.26％, P<0.01), <40 years (<40 years, 48.39％; 40-59 years, 27.62％; ≥60 years 22.45％, P<0.03), multifocality (41.00％ vs. 29.03％, P<0.01), without chronic thyroiditis (36.44％ vs. 20.62％,P<0.01), tumor size >0.5 cm (35.77％ vs. 23.05％, P<0.01) were associated with LNM. Meanwhile, according to the multivariate analysis results, male, multifocality, and tumor size >0.5 cm are independent risk factors for LNM (OR=1.516, 1.743, and 1.788, respectively, all P<0.05). The protective factors for LNM are 40-59 years, ≥60 years, and chronic thyroiditis (OR 0.388, 0.301, and 0.472, respectively,all P<0.05). In the univariate analysis of risk factors for high-volume LNM, the results indicated that being male (6.30％ vs. 2.61％, P= 0.005), <40 years (<40 years, 7.62％; 40-59 years, 2.05％; ≥60 years 0, P<0.001), and tumor size >0.5 cm (4.01％ vs. 1.36％, P=0.027) are associated with high-volume LNM. In multivariate analysis, the results suggest that being male is an independent risk factor for LNM (OR=2.383, P=0.002), whereas age of 40-59 years is a protective factor for LNM (OR=0.270, P<0.001). Conclusion: Lymph node metastasis often ocucrs in cN0 PTMC, whereas high-volume LNM is rare. Being male and <40 years old are risk factors for both LNM and highvolume LNM.

Phillyrin is an important lignans compound from Forsythia. It is not only found in the raw medicinal material with high content, but also shows a variety of pharmacological activities. In the paper, the recent advances in extraction methods, pharmacology-toxicology, pharmacokinetics and the other studies of phillyrin were reviewed in order to provide reference and suggestions for the fur-ther research.

Objective To compare dexmedetomidine with midazolam/fentanyl for sedation in children with pulmonary artery hypertension(PAH) after congenital cardiac surgery.Methods Forty children with PAH were randomly divided into two groups after congenital cardiac surgery.The age of children ranged from 3 to 89 months,and weight ranged from 3 to 26 kg.Group A received an infusion of dexmedetomidine(Dex) 0.5 - 1.0 μg/kg bolus for induction,then a maintenance dose of Dex 0.25 - 0.75 μg · kg- 1 · h - 1.Group B received an infusion of midazolam 0.1 mg/kg bolus for induction,then a maintenance dose of 0.5-2.0 μg·kg-1 ·min-1.The maintenance dose offentanyl was 1.0-1.5 μg·kg-1 · h-1.The time of target sedation score,duration of mechanical ventilation,frequency of using other sedatives and prevalence of delirium were compared between the two groups. Other indicators including COMFORT scale,heart rate ( HR),mean arterial pressure (MAP) and pulse oxygen saturation ( SPO2 ) were compared between the two groups among following time points:before infusion,10 min,1 h,4 h,8 h,12 h after infusion.Results Time points after infusion had lower COMFORT scale significantly compared with time points before infusion(26.3 ± 7.3 ) in group A ( P ＜0.01 ),so as in group B while the COMFORT scale was 23.9 ± 5.9 before infusion.There was no statistics difference of the time to reach the target sedation score between group A and group B [ (4.4 ± 1.5 ) min vs (4.3 ± 1.9 ) min,P ＞ 0.05].The COMFORT scale had no statistic difference among the time points after infusion in the two groups.The COMFORT scale,HR,MAP and SPO2 had no statistic difference between goup A and goup B among time points before and after infusion.Frequency of using other sedatives were significantly lower in group A compare with group B (4.3 ± 3.3 vs 10.7 ± 5.5 ) ( P ＜ 0.01 ).The prevalence of delirium was significantly lower in group A than group B (25％ vs 60％ ) ( P ＜ 0.05).The duration of mechanical ventilation was lower in group A compare with group B [ (40.9 ± 22.3) h vs (46.1 ± 23.1 ) h] but there was no statistics difference.Conclusion Compare with midazolam/fentanyl,single use of dexmedetomidine had sound therapeutic effects to provide sedation for children with PAH,while the latter could decrease the frequency of using other sedatives and prevalence of delirium.

Objective To study the initial application of 3.0T high field intensity intraoperative magnetic resonance(iMR)for cranial tumors.Methods Forty-three patients with cranial tumors including 23 glioma cases,12 pituitary tumor cases,3 brain stem cavernous hemangioma cases,2 meningioma cases,2metastatic tumor cases,1 neurilemmoma case,received operation examined with GE Signa HDX 3.0T iMR system.The operation process and influence of iMR were reviewed.Results In 43 patients,average iMR examination was 1.3(1-3)times.In 16 patients the first iMR examination revealed tumor remnants,and in 13 of them continued surgical interventions and complete resection.The rate of complete resection was increased from 63％(27/43)to 93％(40/43).No complications related to iMR occurred.Conclusion 3.0T high field intensity iMR can provide accurate positioning and real-time navigation for the surgery,increase the rate of complete resection,improve the accuracy and safety of cranial tumor resection,and decrease complications.

Objective To construct a lentiviral expression vector of peroxiredoxin2(PRDX2) RNA interference (RNAi) and to investigate the effect of siRNA of PRDX2 genes on the proliferation of human colonrectal cancer SW480 cell .Methods RNAi tar‐get sequences were designed and synthesized towards the PRDX2 gene sequences .The lentiviral vector pGC‐EGFP‐shPRDX2 was constructed and identified .The vector was transformed into SW480 cells ,and the transfection efficiency was evaluated by fluores‐cence microscopy .The expression of PRDX2 was detected with Quantitative real‐time PCR (qRT‐PCR) and Western blot in the transfected cells .Cell growth and colony forming ability were detected with MTT and plate cloning technique .Results PRDX2 gene lentiviral vector was successfully established and was proved by gene sequencing .The expression of PRDX2 in mRNA and pro‐tein was significantly reduced(P<0 .05) .The PRDX2 mRNA and protein expression in SW480 transfected with lentiviral were sig‐nificantly reduced (P< 0 .05) ,and the ability of growth and proliferation were significantly reduced(P< 0 .05) .Conclusion PRDX2 gene lentiviral vector could be a stable and reliable tool .The proliferation and growth of SW480 cells transfected by pGC‐EGFP‐shPRDX2 could be effectively suppressed ,which could facilitate further investigation of the roles of PRDX2 gene in the de‐velopment and progression of colorectal cancer .

Objective To establish a off-pump leukocyte depletion method in canines.Methods Twenty-one healthy adult mongrel dogs of both sexes, weighing 10-12 kg, were randomized into 2 groups: control group (group C, n = 9) and leukocyte depletion group (group LD, n = 12) . An extracorporeal leukocyte filtration end was constructed by aseptic puncture of the bilateral external jugular veins via a blood transfusion line and the leukocyte filter for extracorporeal leukocyte depletion. In group LD, blood was filtered with a MP-300 blood line and a SQ40S leucocyte depletion filter one end placed in the right external jugular vein (artery end) and the other end placed in the left external jugular vein (venous end). After heparin anticoagulation, a MP-300 blood line pump was used as the power. Blood was filtered at a rate of 75 ml/min and it was maintained for 60 min. The artery end was then closed, normal saline injected into the closed circuit, the remaining blood pumped into the body, and then the venous end closed. In group C, aseptic puncture of the bilateral external jugular veins was performed. Arterial blood samples were taken immediately before leukodepletion (baseline, T_0 ) , at 10, 20, 30, 40, 50 and 60 min of leukodepletion (T_(1-6) , depletion period), and at 10, 20, 30, 40, 50, 60, 120, 180 and 270 min after leukodepletion (T_(7-15) , recovery period) for determination of blood routine. MAP, HR, RBC.Plt and body temperature were recorded at T_0 , T_6 , T_(12) and T_(15) . Results There were no significant difference in MAP and RBC between the two groups ( P > 0.05 ) . HR, body temperature, and Plt were significantly lower in group LD than in group C (P < 0.05) .The leukocyte concentration was lower during depletion period in group LD than in group C ( P < 0.05) , while there was no significant difference in leukocyte concentration during recovery period between the two groups (P > 0.05 ). Conclusion The off-pump leukocyte depletion method is successfully established and has exact efficacy with less adverse effects in this study.