N-myc表达在儿童神经母细胞瘤完全缓解后复发中的作用

目的:探讨N-myc蛋白表达与神经母细胞瘤完全缓解后复发的关系。方法:回顾性分析2005年8月至2018年6月首都医科大学附属北京同仁医院收治的初次完全缓解的神经母细胞瘤患儿49例,其中N-myc阳性组27例,N-myc阴性组(对照组)22例。采用Kaplan-Meier及Cox比例风险回归模型进行分析。结果:49例患儿5年的总生存率、无复发生存率分别为75.7%、65.0%。N-myc阳性组患儿5年的总生存率、无复发生存率分别为64.2%、51.6%,对照组分别为90.9%、81.8%。N-myc阳性组患儿的总生存率、无复发生存率均显著低于对照组(均P<0.05),N-myc表达阳性是导致神经母细胞瘤完全缓解后复发的独立危险因素(P<0.05)。结论:N-myc阳性是导致神经母细胞瘤完全缓解后复发的重要因素。应关注N-myc阳性患儿完全缓解后的巩固治疗及肿瘤复发的监测,最大限度避免治疗后复发,以改善患儿长期预后。

师范生教学实践能力培养问题研究——以X大学为例

师范生教学实践能力水平是我国师范教育质量的重要保证,也是影响师范生顺利从准教师向一名合格教师过渡的关键因素。主要采用访谈法,在X大学师范生参加实习的两所学校,分别为S中学和J中学随机抽取9名实习生及5名实习指导教师,就师范生教学实践能力培养问题进行了深入调研。根据调研结果,基于当前师范学校在师范生教学实践能力培养中存在的问题,提出五点建议:师范学校应加强对师范生教学实践能力培养的重视;逐步完善师范生教学实践能力的培养体制;探索多样化的教学实践能力培养路径;切实提高高校教师的教育教学水平;全面实施师范生教育技能训练计划。

Resonance Suppression Strategy for Humanoid Robot Arm

To address the problem of resonance in the control of a robot arm,a resonance suppression strategy is proposed for a single-joint humanoid robot arm based on the proportionalresonant(PR)controller.First,an arm joint model of the humanoid robot is established.Then the influence of resonance frequency on the performance of the control system with the robot arm is analyzed.The voltage fluctuation of the drive motor caused by the changes in arm motion is recognized as the disturbance of the current loop.The PR controller has the characteristic of disturbance rejection at a specific frequency.The output fluctuation of the driving system caused by the change of arm motion state at the resonance frequency is suppressed.Therefore the output current of the inverter will not be affected by the vibration of the arm at the resonance frequency.Finally,the control system is verified by MATLAB/Simulink simulation.The simulation results demonstrate that the control strategy for the humanoid robot arm based on the PR controller can suppress the resonance of the arm effectively,improving the dynamic performance and system stability.

Knockdown Annexin A8 inhibits the proliferation and invasion of cervical cancer cells

This study aimed to explore the expression,function,and molecular mechanism of ANXA8,the gene for annexin 8,in cervical cancer.Methods:The gene expression of the ANX family members in cervical cancer tissues was classified via The Cancer Genome Atlas(TCGA)database.The expression of ANXA8 in paracancerous tissues,cervical cancer tissues,and cell lines was identified by fluorescence quantitative polymerase chain reaction(PCR)and immunohistochemistry.The effects of ANXA8 knockdown on the cellular growth and cell invasion of cervical cancer were examined by MTT,clone-formation assay,scratch test,and Transwell assay.The effect of ANXA8 knockdown on the proliferative potency of cervical cancer cells was assessed through an in vivo nude-mouse tumor-formation test.The gene expression levels of Ki-67 and ANXA8 in tumor-bearing tissues were measured through Immunohistochemical analysis.Results:TCGA data analysis and fluorescence quantitative PCR exhibited significantly increased expression of ANXA8 in cervical cancer tissues.Further examination exhibited that ANXA8 was expressed exceedingly in cervical cancer tissue,and it was associated with lymph node metastasis,FIGO stage,degree of differentiation,and infiltration depth of cancer patients.Cell-function assays revealed that knocking down ANXA8 may substantially suppress the propagation,colony formation,invasion,and migration of cervical cancer cells.In vivo experiments demonstrated that ANXA8 knockdown had a substantial inhibitory effect on the propagation of cervical cancer cells in nude mice and inhibited the expression of Ki-67.Conclusion:ANXA8 is specifically and significantly upregulated within cervical cancer tissues.The knockdown of this gene showed remarkable outcomes,as evidenced by the substantial inhibition of cervical cancer cell proliferation in in vitro and in vivo experimentations.Therefore,ANXA8 is a potential target or a marker that can serve as a therapeutic or diagnostic tool for cervical cancer.

Real-time transient stability assessment in power system based on improved SVM

Due to the strict requirements of extremely high accuracy and fast computational speed, real-time transient stability assessment(TSA) has always been a tough problem in power system analysis.Fortunately, the development of artificial intelligence and big data technologies provide the new prospective methods to this issue, and there have been some successful trials on using intelligent method, such as support vector machine(SVM) method.However, the traditional SVM method cannot avoid false classification, and the interpretability of the results needs to be strengthened and clear.This paper proposes a new strategy to solve the shortcomings of traditional SVM,which can improve the interpretability of results, and avoid the problem of false alarms and missed alarms.In this strategy, two improved SVMs, which are called aggressive support vector machine(ASVM) and conservative support vector machine(CSVM), are proposed to improve the accuracy of the classification.And two improved SVMs can ensure the stability or instability of the power system in most cases.For the small amount of cases with undetermined stability, a new concept of grey region(GR) is built to measure the uncertainty of the results, and GR can assessment the instable probability of the power system.Cases studies on IEEE 39-bus system and realistic provincial power grid illustrate the effectiveness and practicability of the proposed strategy.

Wastewater reclamation and reuse in China:Opportunities and challenges

The growing water stress both in terms of water scarcity and quality deterioration promotes the development of reclaimed water as a new water resource use. This paper reviewed wastewater reuse practices in China, and the opportunities and challenges of expanding reclaimed water use were analyzed. Rapid urbanization with the increasing of water demand and wastewater discharge provides an opportunity for wastewater reuse. The vast amount of wastewater discharge and low reclaimed water production mean that wastewater reuse still has a great potential in China. Many environmental and economic benefits and successful reclamation technologies also provide opportunities for wastewater reuse. In addition, the overall strategy in China is also encouraging for wastewater reuse. In the beginning stage of wastewater reclamation and reuse, there are many significant challenges to expand wastewater reuse in China including slow pace in adopting urban wastewater reuse programs, the establishment of integrated water resources management framework and guidelines for wastewater reuse programs, incoherent water quality requirements, the limited commercial development of reclaimed water and the strengthening of public awareness and cooperation among stakeholders.

Diagnosis and treatment of infantile malignant solid tumors in Beijing,China:A multicenter 10-year retrospective study

Importance:Cancer is the main cause of death by disease in children.Children experience the highest incidence of cancer in the first year of life.However,there is no comprehensive registration system for children with tumors in China.Objective:To summarize the diagnosis and treatment of infant cancer and analyze the status of standardized diagnosis and management among several treatment centers in Beijing,China,thereby providing evidence to guide further clinical research.Methods:From January 1,2010 to December 31,2019,patients with newly diagnosed infantile malignant solid tumors were admitted to six large tertiary pediatric solid tumor diagnosis and treatment centers in Beijing.The epidemiology,clinical features,and therapeutic effects of tumors in these patients were analyzed retrospectively.All patients were followed up until March 31,2020.Results:In total,938 patients were enrolled in this study.There were 530 boys(56.5%)and 408 girls(43.5%);the median age was 6.0 months(range,0-12.0 months).The three most common tumors were retinoblastoma in 366 patients(39.0%),neuroblastoma in 266 patients(28.4%),hepatoblastoma in 133 patients(14.2%),and central nervous system tumors in 52 patients(5.5%).The estimated 5-year overall survival rate was 81.3%±1.8%,and the 5-year event-free survival rate was 71.8%±2.9%.The 5-year overall survival rates of non-rhabdomyosarcoma soft tissue sarcoma,neuroblastoma,and retinoblastoma were 100%,88%±2.2%,and 86.9%±2.1%,respectively.The 5-year event-free survival rates were 81.1%±2.7%for neuroblastoma,81.6%±9.8%for non-rhabdomyosarcoma soft tissue sarcoma,and 72.7%±14.1%for extracranial malignant germ cell tumors.Interpretation:The three most common infantile malignant solid tumors were retinoblastoma,neuroblastoma,and hepatoblastoma.Multidisciplinary combined diagnosis and treatment is needed for infantile tumors.