Discovery of natural products capable of inducing porcine host defense peptide gene expression using cell-based high throughput screening

Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.

浅析美国高功率微波效应研究动态

简要介绍了美国国际高级研究计划局(DARPA)发布的“波形捷变射频定向能(WARDEN)”项目、空军研究实验室公布的《定向能和基地防御》和《定向能未来2060-美国国防部定向能技术未来40年远景》报告,重点分析了“WARDEN”项目、《定向能和基地防御》和《定向能未来2060-美国国防部定向能技术未来40年远景》报告中的高功率微波效应研究动态,分析归纳了当前美国高功率微波效应研究进展和研究重点是“深化无人机和巡航导弹高功率微波后门扰乱效应机理,提升高功率微波武器系统对无人机和巡航导弹的攻击距离”,这些结论可为我国高功率微波效应研究提供重要参考。

美国定向能机动近程防空计划进展分析

美国定向能机动近程防空(directed energy maneuver-short range air defense,DE M-SHORAD)计划通过击伤、摧毁或压制旋转翼无人机、固定翼无人机以及火箭弹、火炮炮弹、迫击炮弹(rockets,artillery and mortar,RAM)等威胁目标,为机动部队提供伴随防空,对抗新兴威胁,属于美国陆军防空反导现代化的优先项目之一。首先介绍了DE M-SHORAD研制计划;其次详细分析了系统结构,并由系统参数评估了系统的作战性能;最后梳理了系统的研制进展。通过综合分析可知,DE M-SHORAD系统采用最佳组件,通过快速原型方法实现激光武器系统在装甲车上的集成;为降低技术风险,该计划在发展方式上分为两个阶段,首先集成、测试2 kW~5 kW机动实验型高能激光器(mobile experimental high-energy laser,MEHEL),然后再研制50 kW级的多任务高能激光器(multi-mission high-energy laser,MMHEL)。经计算可得:MEHEL和MMHEL对无人机的最大射程分别约为0.77 km、4.8 km。

关于AI大模型技术赋能船舶领域的认识

概述了人工智能(artificial intelligence,AI)大模型研究的焦点、发展趋势及其技术本质,分析了国家层面的人工智能发展战略、国防领域的紧迫需求以及船舶领域应用的基础。从智能绿色船舶的发展、防务装备体系的革新、管控体系的建设以及知识密集产业的转型等方面,探讨了将人工智能大模型技术应用于船舶领域的广阔前景。人工智能大模型技术与“平行系统”“知识工厂”和“数字员工”等理念相结合,能够催生“AI设计”+“数字工厂”+“平行验证”等新型设计、研发和验证手段。此外,人工智能大模型技术可以从船体设计、船舶建造、航运管理、节能减排等方面为船舶行业注入智能和绿色元素,优化船舶各项功能,提高企业运营的效率,提升经济性和环保性。与新能源、新材料、先进制造和电子信息等战略新兴产业结合后,人工智能大模型技术能够基于新理念和新形态塑造未来海洋防务装备体系。同时,人工智能大模型技术能够赋能船舶管控体系的建设,优化规划计划、助力科技创新、提高管理效率和改善用装质效等。特别是随着船舶领域知识工厂的建立、数字人员工的培训、工业机器人的推广以及对深远海领域的拓展,人工智能大模型技术将能够推动船舶领域“自然人”“机器人”和“数字人”的有机结合和密切协同,加速船舶行业向知识密集型和智能密集型升级,使产业生态和价值创造模式向高端化、智能化和绿色化转变,实现更注重质量和效率的发展方式。

拦截高超声速滑翔飞行器:制导进展与展望

聚焦于临近空间拦截制导关键技术,围绕中制导、中末制导交班及末制导等关键问题对临近空间拦截制导技术前景进行展望。首先对临近空间高超声速滑翔飞行器飞行特性进行仿真与分析,并给出防御系统在滑翔段拦截的优势所在;其次,围绕临近空间拦截系统面对高超声速滑翔飞行器时存在的瓶颈进行探讨,并对中制导离线弹道生成与在线弹道生成、中末制导交班及末制导等关键技术相关研究进展进行梳理与总结;最后,结合当前研究进展、面临的挑战及未来临近空间拦截需求,研究分析临近空间拦截制导技术的发展趋势,为后续防御系统的发展提供参考。

高层框架结构E-defense振动台试验弹塑性时程对比分析

长周期地震动对高层结构的影响在日本"311地震"后进一步受到关注,日本学者在E-defense振动台上进行了一20层高层RC框架1/4缩尺模型的加载试验,研究了长周期地震动作用下高层结构的响应及破坏特征;本文在介绍其主要试验结果的基础上,基于SNAP软件建立梁端部集中塑性铰杆单元、柱纤维单元的有限元模型,进行弹塑性时程分析再现试验结果;进一步考虑长周期地震动作用下高层结构长持时、大位移响应特征,对梁端恢复力模型考虑累积塑性损伤修正,计算结果与试验结果吻合良好。

无人旋翼机载激光武器反蜂群作战概念研究

鉴于传统防空手段难以有效应对无人机蜂群的问题,提出了搭载高能激光器的旋翼飞行平台反蜂群概念。首先,通过研究了解典型蜂群的作战特点,分析了无人机蜂群可能的运用模式;其次,通过分析现有防空拦截系统的特性,引出旋翼飞行平台搭载高能激光武器用于打击蜂群的运用方法;最后,分析研究了旋翼机载高能激光武器的可能运用场景、杀伤模式和打击流程。旋翼飞行平台搭载高能激光武器的光速攻击、点面杀伤、全天候打击等特点极其适用于蜂群来袭的运用场景,能够更高效拦截来袭蜂群,可靠保证重要设施的安全。

高速铁路运营安全保障技防体系研究

高速铁路技防技术及系统是高速铁路运营的科技安全保障,高速铁路技防系统在体系级深化融合、风险预警与防控一体化以及统筹标准管理等方面,亟需顶层体系战略架构方法深化研究,以提升和优化高速铁路运营安全保障技防能力。针对高速铁路运营安全保障技防体系发展及建设存在的问题,从高速铁路人防、物防与技防定义和技防体系基础内涵等角度解析技防体系范围边界。依据高速铁路安全及科技发展要求,从规划、管理、系统、创新及融合等方面研究高速铁路技防体系发展规划目标和技防技术实施重点领域。通过深化分析技防体系建设集成总体需求,研究形成运营安全保障技防体系集成架构,并从技防体系集成的服务支撑、功能架构、顶层逻辑交互、物理部署等方面为高速铁路技防体系发展规划提供理论支撑。

The Cross Sectional Study on the Association between Sexual Awareness and Cognitive Social Capital among High School Students in Ho Chi Minh City, Vietnam

Purpose: We aimed to reveal the association between cognitive social capital and sexual awareness among high school students in Ho Chi Minh City, Vietnam, where adolescent premarital sex is considered to be wide-spreading as consequence of socioeconomic changes, in comparison to our previous study in Hanoi, 2012. Methods: We conducted a questionnaire-based survey and a cross sectional study in late 2014, with 2051 eleventh graders at three high schools in Ho Chi Minh City. Complete data was received from 1935 respondents (94.3%). We assessed basic attributes, sexual knowledge, sexual awareness, sexual experience of peers, cognitive social capital such as a sense of community belonging, and Rosenberg Self-Esteem score. After the independent t-test and multiple logistic regression analyses on sexual awareness were performed assigning trivalent Rosenberg Self-Esteem score, sexual knowledge, and sexual experience of peers as independent variables (model 1), followed by analysis adjusted for cognitive social capital (model 2). This study was approved by Japanese Red Cross Akita College of Nursing (No. 24-003). Results: Of 1935 respondents, 99.9% were 16 or 17 years old and mostly from nuclear families (71.1%). Of all participants, 45.8% in males and 49.4% in females correctly answered on sexual knowledge, 47.6% of males and 28.3% of females accepted premarital sex, 60.0% of male and 65.0% of females knew peers with sexual intercourse experience, and 78.1% of males and 79.1% of females agreed with a sense of community belonging. When multiple logistic regression analyses performed, in model 1, sexual awareness was significantly associated with Rosenberg Self-Esteem score in female. In model 2, above association disappeared but significant association was found between sexual awareness and cognitive social capital in both sexes OR (95% CI), male 1.39 (1.05 - 1.84), female 1.99 (1.49 - 2.65). Discussion: The conservative traditional culture in both Hanoi and Ho Chi Minh City seems to be similar to the concept of cognitive social capital and it is considered to have influenced sexual awareness of high school students in Hanoi and Ho Chi Minh City, Vietnam. Conclusion: Cognitive social capital is significantly associated with sexual awareness among high school students in urban areas of Vietnam.

Determinants of Sexual Awareness among High School Students in Tokyo, Japan—Cross Sectional Analysis in Relation to Social Capital

Purpose: The study aimed to clarify the relationship between cognitive social capital and sexual awareness in high school students in Tokyo, Japan. Method: The self-administered questionnaire survey was administered to 1073 high school junior students in Tokyo in Feb. 2017 (collection rate 94.5%). Final analysis subjects totaled 1011 boys and girls (94.2%). True/false questions on timing to wear condom for sex knowledge, acceptability to sexual behavior of high school students for sexual awareness, sense of community belonging for social capital, existence of sexually experienced peers, and Rosenberg Self-Esteem Scale score (binarized with the mean value) were verified. Multiple logistic regression analysis assigning sexual awareness for dependent variable and sex knowledge, sexually experienced peers and Self-Esteem score for independent variable [model 1], including social capital for independent variable [model 2] was performed. The study was approved by Ethical Review Board of sub-organ. Results and Discussion: Out of subjects, 52.6% answered correctly questions on sex knowledge, 33.2% showed tolerance to sexual behavior of high school students, 68.6% had many peers with sex experience, and 75.9% had a sense of community belonging. In model 1, in both genders, having sex knowledge, high Self-Esteem score, and existence of sexually experienced peers was associated with a sense of intolerance to sexual behavior of high school students. In model 2, in both genders, having a sense of community belonging was associated with a sense of intolerance to sexual behavior of high school students [OR (95% CI): boy 1.11 (0.81 - 1.53), girl 1.14 (0.72 - 1.79)]. Persons with high cognitive social capital were likely to have a cautious sense toward sexual behavior. Conclusion: Cognitive social capital was found to be associated with sexual awareness. Cognitive social capital should be emphasized in promoting adolescent reproductive health for the future.

Determinants of Sexual Awareness among High School Students in Tokyo, Japan―Post-Interventional Comparison Analysis in Relation to Social Capital

Purpose: This study was to clarify the association of sexual awareness of high school students with cognitive social capital (SC) in Tokyo, Japan. Method: In September 2017, we conducted a survey of 1073 third-grade high school students who were the same students who had participated in the same questionnaire survey at the prior academic year when they were second-grade students. A total of 1073 students were surveyed and 956 students responded. From six to eight weeks prior to this September 2017 survey, we implemented an educational intervention in the students. Then we compared the results of this survey with the previous survey of February 2017. We used logistic regression to assess sexual awareness and sex knowledge, sexually experienced surrounding peers and Self-Esteem score. The study was approved by the Ethical Review Board. Result/Discussion: Sexual awareness of high school students was significantly associated with SC both before and after the intervention. The higher SC one had, the higher sexual awareness was shown and the greater the sexual caution among both boys and girls was indicated. The study clarified the Determinants of Sexual Awareness of High School Students in Tokyo before and after the educational intervention. Conclusion: SC was found to be significantly associated with sexual awareness. SC should be emphasized in promoting adolescent reproductive health for the future.

SBIRS-HIGH对导弹上升段位置测量精度及中末段位置预报精度的分析

根据目前的技术水平分析了高空天基红外系统(SBIRS-HIGH)的技术参数;理论上计算了SBIRS-HIGH对导弹上升段的位置测量精度以及中末段任意时刻飞行位置的预报精度;研究了SBIRS-HIGH对中段和末端导弹拦截系统的导引能力。

计及台风的含高渗透率风电大电网多时间尺度防御调度策略

为解决我国沿海地区大规模风电接入电网场景下对台风灾害鲁棒性不足的问题,提出一种计及台风的含高渗透率风电大电网多时间尺度防御调度策略。首先,根据台风气象数据建立台风灾害下可调度风电资源评估模型及典型电网元件故障率模型,生成台风灾害下电网故障场景;其次,考虑台风场景下风电出力及故障情景,提出电网失负荷和电网风险指标量化的电网故障损失及概率,分析电网的风险成本;进一步,根据响应速度及能量时移特性对电网的多源调度资源进行分类,以电网风险成本及运行成本之和最低为目标函数构建多源电网多时间尺度防御调度模型,并应用改进海鸥算法对模型进行求解。最后,通过IEEE-39节点算例结果表明,所提出的防御调度策略能协调源-荷的灵活资源,提高电网面对台风灾害的鲁棒性。

多源媒体情绪传播影响了企业策略性专利行为吗?

以我国2008—2020年A股上市公司为样本,考察多源媒体积极情绪传播对企业策略性专利行为的影响。研究发现,多源媒体积极情绪传播通过管理层迎合和管理层防御机制对企业策略性专利行为产生正向影响。进一步研究表明,控股股东两权分离强化了管理层迎合效应的发挥,证监会减持新规的出台并未弱化管理层防御效应的发挥。多源媒体积极情绪传播引起的企业策略性专利行为使得企业产品竞争力和企业竞争地位下降。

基于高强钢筋的人防地下室顶板结构选型分析

人防地下室顶板因设计荷载大,梁板截面配筋率高,在人防工程土建成本中占比居高不下。在合适部位采用高强钢筋,针对顶板结构布置进行选型分析,可有效减少地下室顶板造价。梳理了地下室顶板人防设计荷载与覆土厚度及板短边跨度的关系,分别从理论公式计算取值与规范查表法得到了人防荷载的大致规律。采用加腋大板、单向次梁、十字梁3种布置方案对人防地下室顶板进行了柱跨度、覆土厚度、人防荷载等的参数化分析。综合地下室净高、用钢量等因素,分析表明加腋大板布置方案最优。基于8.7m×8.7m柱跨的加腋大板方案,研究了梁、板采用高强钢筋的经济性及用钢量占比,分析表明人防荷载越大,主要受力构件采用高强钢筋等级越高越经济。

高温胁迫导致水稻颖花败育的机理及其防御措施研究进展

高温胁迫导致的颖花败育已成为水稻减产的主要原因之一。因此,开展高温胁迫导致水稻颖花败育的机理及其防御措施的研究意义重大。本文从高温影响水稻的颖花形成、花粉发育、雌雄蕊结构、开花受精及颖花生理代谢等方面综述了高温胁迫对水稻颖花育性的伤害机理,提出相应的防御措施,包括加强水肥管理、合理喷施外源生长调节剂和选育耐高温品种等,并对未来水稻高温热害的研究方向进行了展望,为开展水稻抗热栽培及合理高温防御措施的选择提供理论依据。

体育与健康课程教学设计与国防教育“六方融合”探究

本文运用文献资料、逻辑分析等研究方法,对新课标背景下体育与健康课程和国防教育在育人方面的融合进行探究,以“两科”的跨学科融合有利于立足核心素养促进学生全面发展为切入点,分析体育与健康课程与国防教育跨学科融合所处环境现状,提出“六方”跨学科融合教学设计建议,旨在为初中体育与健康课程与国防教育跨学科融入教学体系结构完善优化、国防教育知识与技能的掌握、更好培养中国特色社会主义合格建设者和可靠接班人提供相应理论支撑。

基于拦截效率最大化的高功率微波武器系统与中近程防空武器协同作战目标分配模型

针对武器装备技术的发展对防空作战带来的挑战,提出一种基于高功率微波(HPM)武器系统与中近程防空武器协同作战目标分配设计模型。该目标分配模型首先设定作战场景,考虑HPM武器系统的软、硬杀伤效能,与中程防空导弹、近程防空导弹和末端近防炮协同作战,分析HPM武器系统及中近程防空武器的拦截效率,使用模拟退火算法给出目标分配模型求解方法,得出拦截效率最大化的防空武器分配方案。仿真实验结果表明,相比于蒙特卡洛算法和粒子群优化算法,模拟退火算法能够在更短的时间内寻找到拦截效率更高的解,有效解决协同作战中的目标分配问题,为HPM武器系统融入多武器协同防空作战系统奠定基础。

从DARPA看国防科技高风险高回报项目管理模式创新

美国国防高级研究计划局(DARPA)是美军从事颠覆性技术研究与开发的主要管理部门,其在长期的项目管理实践过程中已形成一套行之有效的项目管理模式,值得参考。从科研人员的角度出发,分析DARPA项目管理模式的特点。在此基础上,结合我国防科技发展实际,从鼓励科研人员大胆设想、帮助科研人员细化设想和充分授权科研人员进行项目管理等方面,提出完善高风险高回报项目管理机制的建议。

云南澜沧甘蔗灾害性害虫防控及效果评价

为筛选防控甘蔗大螟和草地贪夜蛾的复合高效广谱配方药剂及高效施药技术,选用35%氯虫苯甲酰胺水分散粒剂、30%甲维盐·杀虫单微乳剂不同配方组合,采用无人机飞防开展3561 hm^(2)防控示范。结果表明:(35%氯虫苯甲酰胺WG 90 g+30%甲维盐·杀虫单ME 2250 mL+农用助剂150 mL)/hm^(2)对中后期大螟具有良好的防控效果,其螟害株和螟害节防效分别为86.58%和90.22%,防控区甘蔗产量和糖分较未防控区平均增加21452 kg/hm^(2)和3.3个百分点;(35%氯虫苯甲酰胺WG 60 g+30%甲维盐·杀虫单ME 3300 mL+农用助剂150 mL)/hm^(2)对苗期大螟和草地贪夜蛾防控效果显著,防效分别为89.53%和95.7%。本研究显示,所用2个配方药剂是防控甘蔗大螟和草地贪夜蛾理想的复合高效广谱配方药剂,可在苗期或中后期大螟及草地贪夜蛾高发期,采用无人机飞防进行叶面一次性喷施。