Objective:To preliminarily investigate the applicability of a poliovirus pseudovirus-based neutralization assay in evaluating the immunogenicity of recombinant poliovirus vaccines and their in vivo potency in rats. Methods:Serum samples from rats immunized with recombinant poliovirus vaccines were tested using both the pseudovirus neutralization assay and the live-virus neutralization assay with Sabin strain. The consistency and correlation of the two methods were analyzed using the Kappa test and Spearman′s rank correlation.Results:For the neutralizing antibodies against typeⅠ, Ⅱ, and Ⅲ polioviruses, the Kappa values for consistency analysis of the two methods were 0.914, 1.000, and 0.751, respectively ( P<0.001), and the correlation coefficients ( R values) were 0.833, 0.927, and 0.859, respectively ( P<0.001). Conclusions:The test results of the two methods are consistent and show a good correlation, indicating that the pseudovirus neutralization assay can be applied to evaluating the immunogenicity of poliovirus vaccines and also can be used in rat potency tests.

Objective:To explore the causes of high noise exposure in PICU, and to provide reference for formulating effective intervention measures to improve the status of noise exposure.Methods:With phenomenological method, eleven nurses of Xinhua Hospital, Shanghai Jiaotong University School of Medicine from August to September 2020 were enrolled by purposive sampling method, and joined face-to-face and semi-structured interviews with researchers. Interview data were analyzed by Colaizzi 7-step analysis method.Results:Four themes were extracted, including the characteristics of PICU, difficulty in equipment alarm management, the crying of children which was difficult to appease, and the low level of knowledge, attitude and practice of noise management of medical staff.Conclusions:High noise exposure of PICU is caused by many reasons. Researchers and managers can optimize the equipment alarm management, implement ideal analgesia and sedation and humanistic care, and carry out noise management training to improve the noise exposure in PICU and the quality of clinical nursing.

Spatiotemporal gait parameters provide important information for the rehabilitation of patients with gait dysfunction. These parameters are often obtained by complex systems such as optical motioncapture system and pressure plates. However, these systems cannot be deployed at the lower-limb rehabilitation robot easily because of high costs, large area occupation and wearable requirements. We present a gait measurement system with a Light Detection And Ranging(LIDAR) laser sensor based on the lower-limb rehabilitation robot. Firstly, to calculate gait parameters, the data are aggregated into left and right legs by the clustering algorithm and the legs contour is fitted with two circles respectively according to the least square method. Then, the spatiotemporal gait parameters are defined based on the time and position of initial contact(IC) and toe off(TO). Finally, to verify the validity of the proposed system, we compared the results of the proposed system with a 3D motion capture system based on a lower-limb rehabilitation robot. Experimental results showed that the gait detection system can measure the parameters within a small range of error that testified the validation of the proposed system. This system proved to be a valid and reliable method for the measurement of gait parameters.
Biomechanical Phenomena ; Gait ; Humans ; Lasers ; Lower Extremity ; Motion ; Robotics

Objective: To investigate a cluster of coronavirus disease 2019(COVID-19)caused by latent infection in Haikou,so as to provide reference for the prevention and control of COVID-19 clusters. Methods: An epidemiological investigation was conducted according to the COVID-19 Prevention and Control Program(Fourth Edition). The course of diagnosis and treatment,clinical characteristics and field investigation data were collected to analyze the transmission chain and the intergeneration between cases. Results : Among 39 people involved,five confirmed cases and two asymptomatic infections were found,with an attack rate of 17.95%. The cases aged from 40 to 65 years and lived in the dormitories near the farm of Dongshan. The first case(named Case 1)closely contacted with a confirmed case of COVID-19 in Chengmai from January 28 to February 10,was isolated on February 13 and developed symptoms on February 16. The other six cases(Case 2 to Case 7)shared the water source with Case 1 from January 28 to February 13(within the incubation period of Case 1). They needed to open the power switch outside Case 1's room and the water valve in Case 1's washroom before the use of water. They might be infected by contacting the doorknob and the water valve contacted by Case 1,or by the aerosol formed after Case 1 used the washroom,then infected each other when living together. The onset of Case 2 to Case 7 was earlier than Case 1,and they had no travelling history in Hubei Province 14 days before and contacted no confirmed cases except Case 1. Therefore,Case 1 was the source of the cluster during his incubation period of COVID-19. Conclusion This was a cluster of COVID-19 due to latent transmission by living in the same area and touching the same objects indirectly,which indicated that COVID-19 was infectious in the incubation period.

OBJECTIVETo retrospectively analyze the clinicopathology of patients with gastric gastrointestinal stromal tumor(gGIST) who underwent radical excision within 18 years in 10 domestic medical centers in order to understand the status of domestic surgical treatment of gGIST.

METHODSClinicopathological data of gGIST patients undergoing radical excision in 10 medical centers from January 1998 to January 2016 were collected, and their operational conditions, postoperative adjuvant therapy, gene detection and survival were analyzed retrospectively.

RESULTSA total of 1 846 cases were recruited in this study, including 246 cases from Guangdong General Hospital, 331 cases from Sun Yat-sen University Cancer Center, 374 cases from Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, 342 cases from Nanfang Hospital of Southern Medical University, 265 cases from Fujian Medical University Union Hospital, 148 cases from Fudan University Shanghai Cancer Center, 49 cases from West China Hospital of Sichuan University, 43 cases from Peking University Cancer Hospital and Institute, 28 cases from the 81st Hospital of Pepole's Liberation Army(PLA), 20 cases from Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute. There were 918 male (49.7%) and 928 female patients (50.3%) with median onset age of 59(18 to 95) years old. Fundus(735 cases, 39.8%) and body (781 cases, 42.3%) of stomach were the common sites of lesions. The average size of tumor was (5.3±4.6) cm. There were 1 421 cases with mitotic count ≤5(77.0%). According to the operation procedure, 924 cases (50.1%) underwent laparoscopic surgery, 759 cases (41.1%) laparotomy, 120 cases (6.5%) endoscopic surgery, and 20 cases (1.1%) laparoscopic combined with endoscopic surgery, 6 cases (0.3%) laparoscopic excision surgery through gastric wall and cavity, and 17 cases (0.9%) laparoscopy and then were transferred to laparotomy. Wedge excision were performed in 1 308 cases (70.9%), proximal gastric excision in 226 cases(12.2%), distal gastric excision in 92 cases (5.0%), total gastrectomy in 94 cases (5.1%), and local gastrectomy in 126 cases(6.8%). Multi-visceral excision was performed in 138 cases, and the splenectomy was performed in 83 cases(60.1%)with the highest ratio. According to modified NIH classification, 399 cases(21.6%) were extreme low risk, 580 cases(31.4%) were low risk, 424 cases(23.0%) were moderate risk, 443 cases (24.0%) were high risk. A total of 461 cases received postoperative imatinib adjuvant therapy, accounting for 53.2%(461/867) of patients with moderate and high risk. Among 1 846 cases, 1 402 cases (75.9%) had complete follow-up data and the median follow-up time was 33.6 (0.1 to 158) months. The 5-year survival rates of extreme low risk, low risk, moderate risk and high risk were 100%, 98.5%, 92.5%, and 79.2% with significant difference(P=0.000).

CONCLUSIONSGastric GIST occurs mostly in fundus and body of stomach in China. Wedge excision is the main operational procedure and laparoscopic operation is over 50%. General prognosis of gastric GIST is quite good.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antineoplastic Agents ; therapeutic use ; China ; Combined Modality Therapy ; Female ; Gastrectomy ; Gastrointestinal Neoplasms ; Gastrointestinal Stromal Tumors ; pathology ; surgery ; Humans ; Imatinib Mesylate ; therapeutic use ; Laparoscopy ; Laparotomy ; Male ; Middle Aged ; Postoperative Period ; Prognosis ; Retrospective Studies ; Splenectomy ; Stomach Neoplasms ; pathology ; surgery ; Survival Rate ; Young Adult

Computational epidemiology is a fast-developing and interdisciplinary research area .Through comprehensive computation-analysis of multi-uncertain factors affecting the epidemic process , this method may add to our knowledge about epidemic patterns and help design reasonable response plans and emergency strategies .This article briefly summarizes the idea and theory of computational epidemiology based on related researches in the recent years , introduces the application of this method in case of smallpox bioterrorism and influenza pandemic , and predicts the development of this area .

The use of the Internet big data to discriminate the early symptoms of unexpected biological events has be-come a frontier research area in biosurveillance .This paper mainly introduces the principle , method, practical applications of big data based biosurveillance , and the future development of this new research field .

Modeling biosecurity events based on mathematical theories to reveal the inherent mechanism can shed light on the development of biosecurity events and offer accurate scientific support to emergency preparation and response , con-tributing much to national biodefense capability .This paper reviews the applications of mathematical theories as a research and analytic tool in biosecurity and discusses the trends of development in this field .

To explore the transmission patterns and advise public health departments , this paper establishes a dynamic model on the peculiarity of avian influenza A (H7N9) virus and analyzes the dynamic feature of this type of bird flu trans-mission between humans and birds .Results show that this type of bird flu can be controled , and that closing down live-bird markets is the most effective method .

Human behavior significantly affects the spreading dynamics of infectious diseases in large populations .The study of the interplay between the adaptive behavior and the epidemic dynamics underlies the professional information release and psychological counseling mechanism and is conducive to disease control and social panic elimination .This paper aims at the investigation of the effect of adaptive behaviors on the spreading dynamics of epidemics in structured populations .We analyzed the empirical data on adaptive behavior from several large epidemics after the outbreak of SARS in 2003 and confirmed the induction effect of two main information sources on adaptive behavior , e.g., public available information and local perceived information .Then we investigated the effect of adaptive behavior on epidemic dynamics in a structured population based on two primary models , e.g., health-belief model and network model .The results showed that the individual adaptive behavior had significantly decreased the chance of infection and thus mitigated the epidemics . Human adaptive behavior has a significant effect on spreading dynamics of epidemics .An effective information release mechanism will induce human adaptive behavior and is thus conducive to control of epidemics .