In recent years, the incidence of pancreatic cancer shows rising trend and higher mortality. Pancreatic cancer lacks early diagnostic methods with high sensitivity and specificity, and the surgical resection rate is 10 %-20 % with high operation mortality, poor long-term curative effect and less than 5 %survival rate within 5 years. At present, researchers indicate that radiotherapy can improve the quality of life, increase tumor local control rate and prolong the overall survival time of patients with pancreatic cancer in different levels. Diffusion weighted imaging (DWI), as a functional imaging technology of magnetic resonance imaging (MRI), is the only way to react cell levels. This paper will summarize the application of DWI in radiotherapy of pancreatic cancer.

Objective; To evaluate the influence of electrolyte's concentration at micro-arc oxide treatment on the bonding strength of titanium to porcelain. Methods; CP titanium specimens with size of 25 mm ×3 mm ×0. 5 mm were treated with micro-arc oxidation (MAO) in Na_2SiO_3 solution of three different concentrations. After ultra-low-fusing porcelain was applied, a three-point-flexure-test was used to evaluate the bonding strength of titanium to porcelain. The surface of the specimens was observed by SEM and EDS, as well as the interface between titanium and porcelain. Results; The bonding strength values between titanium treated with MAO and porcelain was significantly higher then the control groups, Croup 20 g/L has the highest bonding strength values. SEM/EDS suggested that a porous thin layer of oxide which contains Si element is created by MAO, and higher concentration of Na_2SiO_3 leads to more Si element in oxide. Conclusion; MAO treating can improve the bonding strength between titanium and ceramic. Electrolyte's concentration has an effect on the bond strength between titanium and porcelain.

Objective To analyze the incidence and the risk factors of retinopathy of prematurity (ROP) among the multiple and single gestations births.Methods A prospective control study was applied to the research.The preterm infants were selected that from September 2013 to December 2015 in neonatology department of our hospital.They were divided into multiple gestations group (52 cases) and single birth infants group (600 cases).RetCam Ⅲl retina camera and binocular indirect ophthalmoscope video were used to screening the ocular fundus.The cure rate of the two groups was compared with chi-square test.Results The incidence of ROP in multiple gestations group (32.69％) was higher than single birth infants group (20.83％) (P =0.047).There was significant difference about the multiple and single gestations births in ≤ 30 weeks (P =0.040),and there was no statistically significant difference in ＞ 30 weeks (all P ＞0.05).With the increase of birth weight,the ROP detection rate of two groupa was reduced.There was no statistically significant difference about different birth weight among the two groups (all P ＞ 0.05).The oxygen usage of ＞ 5 days ROP detection rate was higher than 5 days or less in the two groups (P =0.025,0.001).There was no significant difference in ROP detection rate between two groups with ≤5 d oxygen usage.There was significant difference about the multiple and single gestations births in oxygen usage of ＞ 5 days (P =0.020).Multivariate analysis found that multiple gestations and small gestational age were risk factors for ROP.Conclusion The smaller gestational age,the lower birth weight,and the longer oxygen therapy with the preterm infants,the higher the incidence of ROP.The number of different gestational is also the influences factors of ROP.Multiple gestations overall incidence of ROP is higher than the single birth infants.The smaller the gestational age and the longer oxygen usage,multiple gestations incidence of ROP is higher than single gestation in different births.However,there is no relationship in different birth weight among the multiple and single gestations.

Objective To investigate the differences in tumor volume and metastatic tumors of the liver and regional lymph nodes between contrast-enhanced computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DWMRI) through a comparative analysis,as well the useful information for target volume delineation,and to guide radiotherapy in clinical practice.Methods A total of 40 patients with pancreatic cancer were enrolled and underwent contrast-enhanced CT and DWMRI in the same position.The target volume was delineated,the major axis of the maximum tumor section was measured,and the numbers of liver metastatic tumors and metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm were measured based on the CT and DWMRI images.The analysis was performed by using paired t-test or paired Wilcoxon rank sum test.Results The mean gross tumor volume (GTV) delineated by contrast-enhanced CT and DWMRI was 54.95 cm3 and 41.67 cm3(P =0.000),and the mean value-different value was 13.28 cm3.The major axis of the maximum tumor section measured by contrast-enhanced CT and DWMRI were 4.18 cm and 3.94 cm (P=0.000),respectively,and in two patients,dCT was smaller than dDWMRI.A total of 83 liver metastatic tumors were identified by contrast-enhanced CT,and 112 were identified by DWMRI;the liver metastatic tumors detected by contrast-enhanced CT accounted for 74％ of those detected by DWMRI.As for the metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm,103 or 46 were detected by contrast-enhanced CT,and 200 or 56 were detected by DWMRI,and the tumors detected contrast-enhanced CT accounted for 52％ or 82％ of those detected by DWMRI.There were significant differences in all data between contrast-enhanced CT and DWMRI.Conclusions GTV and the major axis of the maximum tumor section measured by DWMRI are lower than those measured by contrast-enhanced CT,and contrast-enhanced CT is sensitive in detecting the metastatic tumors of the liver and lymph nodes.However,it is necessary to conduct further controlled experiments with reference to pathology.

Objective To investigate the relationship between impulsive behaviors and the errorrelated negativity (ERN) component of event-related potentials of error processing in heroin addicts.Methods Using the paradigms for psychological experiment,the Iowa gambling task (IGT) was performed both in heroin addiction group (HA group,20 cases) and healthy control group (HC group,20 cases),and the inspection of electroencephalography was underwent in all subjects concurrently.Following the collection of data,the amplitude and latency of ERN were compared between the two groups,and then the relationship between the amplitude of ERN and the scores of Barratt Impulsiveness Scale (BIS-11) was analyzed separately.Results Decision-making course had no effect on the net score remarkably in HA group (F =1.21,P ＞0.05).Compared with HC group(64.3 ±8.4,73.8 ± 16.4),BIS score as well as the numbers of high frequency loss cards were significantly higher in HA group(75.2 ±7.6,105.5 ±22.2; t =-5.39,-9.24 ; P ＜ 0.05),while both the two groups had visible waveforms of ERN,and the amplitude was markedly lower in HA group(HA:(4.23 ±0.87) μV,HC:(6.11 ± 1.09) μV; t =5.96,P ＜0.05),but no statistical difference was found in latency of these two groups(HC:(102.1 ±28.2) ms,HA:(107.8 ±24.2) ms;t =-0.62,P =0.54),and the amplitude of the two groups was negatively associated with BIS score respectively in both two groups (HC:r =-0.66,HA:r =-0.78 ; both P ＜ 0.05).Conclusion The reduced capability of error processing maybe partly contribute to both addiction and relapse to heroin addict,and the ERN event-related potential could be regarded as an indicator of impulsive behaviors and the capability error processing.

Objective:To study the epidemiological characteristics and mixed infection of adenovirus in acute respiratory tract infections in Shanghai from 2015 to 2019, and to provide scientific basis for the prevention and control of adenovirus.Methods:Acute respiratory tract infections were collected from 3 hospitals in Shanghai from 2015 to 2019. Relevant information was registered and respiratory specimens were sampled for detection of respiratory pathogens by multiplex PCR.Results:A total of 1 543 cases of acute respiratory tract infection were included. The positive rate of adenovirus was 2.92%(45/1 543), the positive rates of influenza like illness (ILI) and severe acute respiratory illness (SARI) were 2.74%(29/1 058) and 3.30%(16/485), respectively. The positive rate of ILI during January-May 2019 was 5.43%(7/129), higher than that in the same period of 2015- 2018 (0.52%-4.48%) (Fisher’s exact test value=8.92, P=0.036). The incidence of adenovirus-positive cases was mainly distributed in the first and second quarters, accounting for 62.22% (28/45). The difference of the incidence of adenovirus-positive cases in each quarter was significant ( χ2= 12.52, P=0.006). The positive rate in the second quarter was highest (6.03%), which was higher than that in other quarters (1.89%-2.93%). There were significant differences among different age groups ( χ2=16.94, P=0.001), and the positive rate decreased with age ( χ2=10.16, P=0.001). The positive rate of 13-19 years old group (9.43%) was higher than that of other age groups (1.48%-4.81%). The positive rate of student group (12.07%) was higher than that of other occupations (2.61%). The difference was systematic ( χ2=11.53, P=0.001). Mixed infection accounted for 31.11% (14/45) of 45 adenovirus positive cases. The mixed infection rates of ILI and SARI were 34.48% (10/29) and 25.00% (4/16), respectively. Among 14 cases of mixed infection, the main mixed infection pathogens of adenovirus were influenza A virus and coronavirus. Conclusion:Adenovirus surveillance should be further strengthened in adolescents with a focus on students and other key groups in the second quarter.

Objective:To analyze the epidemiological characteristics of imported COVID-19 cases in early phase in Shanghai, introduce measures and provide reference for prevention and control of imported COVID-19 cases.Methods:Data of imported COVID-19 cases in Shanghai reported as of 30 March, 2020 were obtained from National Notifiable Disease Report System of China CDC and field epidemiological investigation reports by CDCs in Shanghai. The information about measures of prevention and control was collected from official websites and platforms of the governments. Data cleaning and statistical analysis were performed with softwares of EpiData 3.1, Excel 2019 and SAS 9.4.Results:A total of 171 imported COVID-19 cases had been reported as of 30 March, 2020 in Shanghai, including 170 confirmed cases and 1 asymptomatic infection case. Among them, cases of Chinese nationality accounted for 71.3% (122/171) and cases of foreign nationality accounted for 28.7% (49/171). The median age of the cases was 23 years ( P 25, P 75: 18, 35 years), and the male to female ratio of the cases was 1.3∶1. Students accounted for 56.6% (97/171). About 45.6% (78/171) of the cases fell ill before arriving in Shanghai. The cases with mild or common clinical manifestation accounted for 96.5% (165/171) and no significant difference in clinical type was observed between overseas Chinese cases and foreign cases. The epidemic curve by diagnosis date reached peak on March 24, and the number of the cases gradually declined due to the closed-loop management process of joint port prevention and control mechanism. The 171 imported COVID-19 cases were mainly from 24 countries and regions, including the United Kingdom (64 cases, 37.3%), the United States (32 cases, 18.6%), France (19 cases, 11.0%) and Italy (16 cases, 9.4%). About 40.4% of the cases (69/171) planned to continue travelling to 21 other provinces and municipalities in China. Customs quarantine and community observation/detection points identified 43.9% (75/171) cases and 31.0% (53/171) cases, respectively. Conclusions:The imported COVID-19 cases in early phase in Shanghai were mainly young population and students accounted for high proportion. The imported risk of COVID-19 was consistent with the severity of the epidemic in foreign countries. The closed-loop management model of the joint port prevention and control mechanism plays an important role in the identification and management of the imported COVID-19 cases.

Objective:To investigate Helicobactor pylori (H. pylori) infection status and interfamilial transmission pattern in Zhengzhou area. Methods:A cross-sectional study was conducted from September 2020 to march 2021, among 731 individual from 266 families randomly selected from 9 communities of Zhengzhou area. H. pylori infection status was determined by serum antibody tests, and 13C-urea breath test was performed in the previously eradicated population to clarify the current infection status. The individual and familial infection rate, infection status for couples and children and adolescent were analyzed. Results:Among 731 individuals from 266 families, 397 of them were H. pylori positive. The individual infection rate was 54.31% (397/731); among infected individuals 77.83% (307/397) were infected with type Ⅰ strain, 22.67% (90/397) were infected by type Ⅱ strain. Annual household income ( χ2=0.419, 0.410, 0.213, all P>0.05), smoking history (χ 2=0.071, P>0.05), drinking history ( χ2=0.071, P>0.05), dining place ( χ2=0.009, P>0.05), gastrointestinal symptoms ( χ2=0.047, P>0.05), family history of gastric disease ( χ2=0.069, P>0.05), and history of gastric cancer ( χ2=0.004, P>0.05) had no significant differences between H. pylori-positive and -negative groups, but the infection rate in individuals with higher education level was lower ( χ2=4.449, P<0.05). The infection rate was significantly higher in≥18 age groups compared with<18 age groups ( χ2=6.531, 23.362, 20.671, 24.244, 37.948, 14.597 and 5.170, all P<0.05). The familial H. pylori infection rate was 87.59% (233/266), and in 61 families all member were infected (26.18%, 61/233). The positive rate was 23.08% (6/26) in 50 families with children under 18 years when both parents were infected. Among 231 coupled families, both couples were infected in 78 families (33.76%), one couple was infected in 113 families (48.92%), and both couples were not infected in 40 (17.32%). With the increase of marriage time, the infection rate of both spouses increased significantly ( χ2=7.775, 12.662, 15.487, all P<0.05). Conclusions:The distribution of H. pylori infection presents a family cluster pattern, and intrafamilial infection is an important transmission rout of H. pylori. The type I strain of H. pylori is the dominate strain in this area.

Objective:To analyze the changes in the epidemiological characteristics of scarlet fever cases in Shanghai City before and after the outbreak of coronavirus disease 2019 (COVID-19), and to provide a reference for scientific prevention and control of scarlet fever.Methods:The information of scarlet fever reported cases in Shanghai City from January 2016 to June 2021 in the information system of Chinese Disease Prevention and Control was collected, and the differences in time trend, regional distribution, age and gender distribution of cases before and after the outbreak of COVID-19 in Shanghai City were analyzed by descriptive epidemiologic method.Results:The incidence rate of scarlet fever reported in 2016-2019 was (0.22-4.02)/100 000 in each month, with a median of 1.13/100 000. During January 2020 (the outbreak began in Shanghai City) and June 2021, the incidence rate of scarlet fever was (0.01-1.64)/100 000, with a median of 0.14/100 000, which was 12.39% of that before the outbreak of COVID-19. During February and June 2020, the monthly reported incidence rate of scarlet fever was (0.18-0.58)/100 000, showing an upward trend compared with the same period in 2020 ((0.01-0.05)/100 000). From 2016 to 2019, the annual reported incidence rate of each district was (0.55-65.48)/100 000, with a median of 9.57/100 000; while in 2020, the annual reported incidence rate of each district was (0.29-9.85)/100 000, with a median of 2.18/100 000, which was 22.78% of that before the outbreak of COVID-19. The incidence of scarlet fever dropped significantly. The incidence rate in Minhang District was still the highest. The cases were mainly four to eight years old, and there was no substantial difference of the proportions before and after COVID-19 pandemic, with the incidence rate of six years old group the highest. The proportion of male was more than female in reported case, while the male ratio in reported cases was not significantly different before and after COVID-19 pandemic.Conclusions:The incidence rate of scarlet fever in Shanghai City has dropped sharply after COVID-19 pandemic. The main epidemiological characteristics of the regional and population distribution of cases remain unchanged.

Objective:To analyze the epidemiological characteristics of a cluster of 5 confirmed COVID-19 cases related with the transmission in incubation period of initial case, and find out the infection source and transmission chain.Methods:According to "The Prevention and Control Protocol for Coronavirus Disease 2019 (Third Edition)" issued by the National Health Commission, a field epidemiological survey was conducted for the 5 cases in January 2020. Nasopharyngeal swabs and sputum samples were collected from them for the detection of 2019-nCoV by real time RT-PCR. Multi prevention and control measures were taken, such as tracking and screening close contacts, medical isolation observation, investigating the epidemiological link, analyzing transmission chain.Results:Case 1, who had common environmental exposure with other COVID-19 cases, got sick on 20 January, 2020 and was confirmed on 1 February. Case 2 became symptomatic on 22 January and was confirmed on 27 January. Case 3 got sick on 25 January and was confirmed on 30 January. Case 4 had illness onset on 20 January and was confirmed on 1 February. Case 5 got sick on 23 January and was confirmed on 31 January. Among the 5 cases, case 2 died and the illness of other cases were effectively controlled. After exclusion of other common exposure factors, case 1 had a 6-hour meeting with case 2 and case 3 on 19 January. Case 2 and case 3 might be infected by case 1 during the incubation period. It is the key point for epidemiological investigation.Conclusion:The epidemiological investigation indicates that the transmission might occur in the incubation period of COVID-19 case, close attention should be paid to it in future COVID-19 prevention and control.