Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.

The Protective Effects of Flavonoids from Scutellaria Baicalensis Georgi Stems and Leaves on Oligodendrocyte Damage Induced by Aβ1-42

Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ1-42-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ1-42, an injury model was established by subjecting OLN-93 cells to Aβ1-42 exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ1-42. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ1-42-induced damage of OL.

Mesenchymal stem cells-based drug delivery systems for diabetic foot ulcer:A review

The complication of diabetes,which is known as diabetic foot ulcer(DFU),is a significant concern due to its association with high rates of disability and mortality.It not only severely affects patients’quality of life,but also imposes a substantial burden on the healthcare system.In spite of efforts made in clinical practice,treating DFU remains a challenging task.While mesenchymal stem cell(MSC)therapy has been extensively studied in treating DFU,the current efficacy of DFU healing using this method is still inadequate.However,in recent years,several MSCs-based drug delivery systems have emerged,which have shown to increase the efficacy of MSC therapy,especially in treating DFU.This review summarized the application of diverse MSCs-based drug delivery systems in treating DFU and suggested potential prospects for the future research.

HPLC fingerprint of Nauclea officinalis stems in different harvesting period

Objective:To establish HPLC fingerprint of Nauclea officinalis stems in different harvesting periods,and analyze the effect of harvest time on the quality of the medicinal materials by combining with chemical pattern recognition.Methods:The analysis was performed on Sun Fire-C18(150 mm×4.6 mm,5μm)column.The mobile phase consisted of acetonitrile-0.1%phosphoric acid solution(gradient elution)at a flow rate of 1.0 mL/min.Results:The HPLC fingerprint of Nauclea officinalis stems was established and 12 common peaks were determined,and 3 chromatographic peaks were identified by comparison with the mixed references.There were some differences in the quality of Nauclea officinalis in different harvesting periods.The OPLS-DA analysis successfully predicted four main markers of quality difference.Conclusion:The established HPLC fingerprint could reflect the composition characteristics of Nauclea officinalis stems in different harvesting period,and the main markers that influence the composition difference of the stems could be used as key indicators for the quality control.

Study on the Action Mechanism of Isodon suzhouensis Stems in the Treatment of Prostate Cancer Based on UPLC-Q-TOF-MS/MS Combined with Network Pharmacology and Molecular Docking

[Objectives]This study was conducted to explore the action mechanism of chemical components from stems of Isodon suzhouensis on prostate cancer based on UPLC-Q-TOF-MS/MS technique,network pharmacology,and molecular docking validation.[Methods]UPLC-Q-TOF-MS/MS was applied to search active components in stems of I.suzhouensis,and SwissTargetPrediction and PharmaMapper databases were used to predict their potential targets.The GeneCards database was adopted to screen the targets of prostate cancer,and the targets of the active components and the targets of prostate cancer were intersected to obtain common targets.A protein-protein interaction network was constructed,and also,an"active component-target-disease-pathway"network was constructed using Metascape for gene ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis.Moreover,AutoDock was adopted to perform molecular docking verification on key active components and core targets.[Results]Sixty three active components were screened from stems of I.suzhouensis,and they had 233 common targets with prostate cancer,mainly involving biological processes such as protein phosphorylation,response to hormones,active regulation of cell movement,cell response to lipids,and response to oxidative stress,as well as pathways in cancer,prostate cancer,micro ribonucleic acids in cancer,p53 signaling pathway,NF-κB signaling pathway and other signaling pathways,exerting anti-tumor effects.Molecular docking showed that the top 5 key active components had good binding ability with the top 5 core targets.[Conclusions]Active components from stems of I.suzhouensis can exert therapeutic effects on prostate cancer through multiple targets and pathways.

Cemented versus uncemented stems for revision total hip replacement:A systematic review and meta-analysis

BACKGROUND The popularity of uncemented stems in revision total hip arthroplasty(THA)has increased in the last decade.AIM To assess the outcomes of both cemented and uncemented stems after mid-term follow up.METHODS This study was performed following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for systematic reviews and meta-analysis guidelines.Articles were chosen irrespective of country of origin or language utilized for the article full texts.This paper included studies that reviewed revision THA for both cemented or uncemented long stems.RESULTS Three eligible studies were included in the meta-analysis.Analysis was conducted by using Review Manager version 5.3.We computed the risk ratio as a measure of the treatment effect,taking into account heterogeneity.We used random-effect models.There were no significant differences found for intraoperative periprosthetic fractures[risk ratio(RR)=1.25;95%confidence interval(CI):0.29-5.32;P=0.76],aseptic loosening(RR=2.15,95%CI:0.81-5.70;P=0.13),dislocation rate(RR=0.50;95%CI:0.10-2.47;P=0.39),or infection rate(RR=0.99,95%CI:0.82-1.19;P=0.89),between the uncemented and the cemented long stems for revision THA after mid-term follow-up.CONCLUSION This study has evaluated the mid-term outcomes of both cemented and uncemented stems at first-time revision THA.In summary,there were no significant differences in the dislocation rate,aseptic loosening,intraoperative periprosthetic fracture and infection rate between the two cohorts.

论STEM教育的本土化建构:内涵、价值及实践探索

STEM教育很早就被引入国内并成为我国科技与工程教育的重要教育理念和方式。但是作为一个“舶来品”,在我国面向未来的教育改革中,STEM教育必须进行本土化建构,才能更好地服务于我国科技创新人才培养的需求。内涵上,在我国中小学教育领域,“STEM教育”这个术语有着多种既相互关联又兼具不同指向的多元内涵:它既是一个研究领域、一种育人理念,又是一种课程形态、一种教学方式。价值上,我国STEM教育有着自己的教育实践土壤,必须通过本土化改造,突出育人方式变革,聚焦核心素养发展,培植现代化的教育生态,才能发挥其育人价值,真正成为我国学校教育的重要表征。虽然STEM教育自21世纪初被引入后日趋与我国教育改革实践相融合,但当前仍然面临教学方式固化、教育目标不清、教师能力不足等现实问题。在推动教育现代化发展和教育数字化战略行动的大背景下,唯有将STEM教育研究及其本土化改造与创新融入我国教育改革的内在构成之中,才能使其在我国发挥持久的生命力。

谷子新品种及其轻简高效生产技术的综合评价

冀谷39是国家谷子高粱产业技术体系“十三五”期间的重大研发成果之一,其特点突出且实现了品种经营权转让,但在实际生产过程中出现播种不匀、产量不稳、收割损失以及种植户不认可等问题。为更好解释、澄清上述问题,进一步做好冀谷39及其轻简高效生产技术的示范推广工作,通过开展实地调研,采用STEM系统评价方法,从科学可行性、技术可行性、经济可行性、模式可行性4方面,开展冀谷39及其轻简高效生产技术经济评价。评价结果显示,该品种及轻简高效生产技术推广属可行范畴,并且与其他谷子和玉米相比,在增产、增收以及生态效益方面表现优异。因此建议以政府、科研、经营主体及农户等多方共同协作,实现优质新品种的推广示范,使适应性优良的新品种及高效的配套栽培技术得到更广泛的推广应用。

STEM课堂中创造性思维评价体系的构建与应用

STEM教育的跨学科性、探究性、协作性为创造性思维培养提供了良好的环境氛围与基础条件,然而当前STEM课堂学生创造性思维评估难题却始终未得到有效解决。研究基于创造性思维内涵要素解构以及PISA 2021创造性思维评估模型等现有理论基础,构建STEM课堂中创造性思维评价指标框架,结合专家意见和建议形成了包括“想法生成”“实施探索”“分析评估”“迭代优化”“协作沟通”5个一级指标、20个二级指标的STEM课堂中创造性思维评价指标体系,并通过层次分析法说明评价指标体系结构维度及权重分配的合理性,最终将指标体系应用于教学实践以反思效果并提出建议。研究为构建科学合理的评价指标体系、有效评估STEM学生的创造性思维提供了重要支撑和决策依据。

STEM视域下初中化学跨学科项目式学习实践研究——以“探寻火箭发射的奥秘”为例

基于STEM教育理念,以“探寻火箭发射的奥秘”为载体,引导学生进行跨学科项目式学习,以“探究火箭原理”“再探火箭燃料”“模拟火箭设计和制作”“成果展示与评价”四个子任务驱动,引导学生运用多学科知识设计和制作三种模拟火箭,有效提升学生的综合素养,实现跨学科协同育人。

融合STEM理念促进认识方式发展的主题式学习——以“乙烷脱氢制乙烯工艺发展研究”为例

以“乙烷脱氢制乙烯工艺发展研究”为主题,融合STEM理念,开展高中化学主题式学习。通过完成“乙烷热裂解制乙烯”“乙烷蒸气裂解制乙烯”“乙烷催化氧化脱氢制乙烯”等3个子任务,巩固化学反应与能量、化学反应速率、化学平衡等核心知识,发展化学学科能力和工程思维,形成化工生产三维认知模型。

论STEM教育是科学教育的完成形态

科学教育语境下的科学是指自然科学,它属于经验科学。作为知识的科学是真理体系的一部分,它表现为与经验事实保持一致的、可证伪的精确判断的命题网络;作为方法的科学是指“接受-怀疑-猜想-检验”的认识过程;作为价值的科学是指科学精神,比如,好奇心驱动、独立自主、基于事实等,以及科学研究伦理规范。基于“知识-方法-价值”的理解框架,科学教育的宗旨是培养学生生活世界中的科学素养,即“懂科学、用科学、倡科学”。由此,科学教育的完成形态必然是STEM教育。为了STEM教育的可持续、高质量的发展,我们需要利用教育众筹机制,应对STEM现代课程开发、专业的科学教师队伍培育以及基于质的教育过程管理这三个相互关联的系统性挑战,从而将课程开发、教师专业发展以及教育过程管理融为同一个过程。这个过程同时也是教育现代转型的过程。

澳大利亚STEM教育政策分析与启示

近年来,澳大利亚政府部门、学术组织推出促进STEM教育发展的系列政策。这些政策主要受澳大利亚政治体制、技术发展、社会性别因素的影响,政策行动者呈现出多元化特点。政策内容在制度领域、资源配置和教与学方面都有涉及,但以资源配置为主。在政策实施上以项目为主并注重继承与创新。借鉴澳大利亚的做法,我国STEM教育政策的制定应成为多部门的责任,在内容上可综合考虑制度领域、资源配置和教与学等方面,同时在实施中加强推广成熟做法。

中、美、澳STEM教师专业标准 及其实施效益:比较与启示

中、美、澳STEM教师专业标准,因国情不同而各有特点:美国制定了四大领域的教师专业标准,澳大利亚则是在多元主体参与下制定普适性STEM教师专业标准架构,而中国出台了专门的STEM教师能力等级标准,强调培养复合型的跨学科教师,尚处于摸索阶段。美、澳作为STEM教育的先发国家,其STEM教师专业标准的实施效益总体良好,值得借鉴。我国需要博采国际经验,加快STEM教师专业标准的完善,尽快培养出一支数量足够、素质优良的STEM师资队伍。

家社联动:美国社会机构参与家庭STEM教育——基于STEM未来希望基金会的个案研究

自20世纪60年代起,美国政府开始关注家庭参与教育及相关政策的制定。但目前,美国不同家庭获取教育资源的差距依旧明显。在此背景下,一些社会机构做出了积极响应,多方参与家庭教育,实现教育的家社联动,美国STEM未来希望基金会便是其中之一。它支持并与众多机构合作,搭建多方参与的家庭STEM教育支持网络;赋能家庭参与STEM教育,包括提供丰富的STEM学习资源,为家长参与STEM教育提供指导,提高家庭STEM教育信心;为家庭引进多样化学习模块,多方互动提升家庭STEM教育能力,亲子共学提振家庭STEM学习氛围。这些都为家社联动开展STEM教育进行了积极探索,也为我国推进家校社合作提供了借鉴。

以色列STEM教育体系与特征探微

以色列的社会和经济发展与科技创新紧密相关,而其STEM教育体系是科技创新的支撑。以色列构建起由多元主体参与的STEM教育体系,包括政府部门统筹协调STEM教育发展、国防部在以色列STEM教育体系中扮演关键角色、中小学开设丰富多彩的STEM课程、高等教育机构为国家培养大批工程师和科学技术人才、企业和社会组织积极投身STEM教育,并以多样化的项目为载体助推STEM教育发展。以色列国家安全和经济产业发展需要决定其高度重视STEM教育,特殊国情为其STEM教育发展带来阻碍和助推两方面作用。为STEM教育营造有利的政策环境,多元主体协同参与对以色列STEM教育发展具有重要推动作用。

初中STEM课程中元认知能力培养的策略研究

STEM教育具有多学科整合、基于项目的协作学习和真实的问题解决情境等学科特征。然而,对于习惯于传统教学方法的学生来说,由于缺乏系统的认知能力和调节能力,容易导致STEM教育的教学效果不佳。元认知能力是建立在一定的元认知知识和情感的基础上,对自身认知活动进行调节和控制的高级能力。有研究表明,培养学生的元认知能力可以提高其在STEM教育中的学习能力、学习成绩和学习效果。然而,现有研究大多将某个策略应用到STEM教育中培养元认知能力,或者聚焦于元认知能力某一维度的培养,缺乏系统全面的元认知能力培养策略。因此,本研究根据元认知的结构和STEM教育的特点,提出了在STEM教育中全面系统地培养元认知能力的策略模型。而后,本研究通过准实验研究法验证以上策略的应用效果,在STEM课程中,实验组采用元认知培养策略,对照组采用传统方法进行教学。根据问卷数据的ANCOVA分析结果,得出以下结论:①元认知培养策略可以有效提高学生的元认知能力,包括元认知知识、元认知经验和元认知监控;②元认知培养策略可以促进学生的学习成绩和知识获取。

美国生物医药产业人才供给经验及启示

美国是当今世界生物医药的头号强国,其强大的创新能力离不开人才队伍的支撑,考察其人才供给经验,发现四个值得关注的方面:一是学科专业规模、结构、布局与产业需求同步协调发展,二是对全球范围优质生源的吸引力度超越了政策及疫情局限,三是相关专业管理机构、企业、研究机构积极参与人才培养,四是通过教育或资助方案延伸与拓展人才培养链条。借鉴美国的经验,建议我国试点放开先导产业领域相关学科专业设置及招生自主权,推动科研机构与企业助力后备人才的前沿知识储备与技能提升,推动大中小一体化培养STEM人才。

非正式学习环境中的STEM教育:美国博物馆学习服务案例研究

非正式学习环境为STEM教育提供了独特的机会和资源。作为非正式学习环境的典型代表,美国博物馆以知识共享为使命,通过策划丰富多样的教育活动,为各年龄段学生提供有针对性的STEM教育资源。研究聚焦于美国国家自然历史博物馆、旧金山探索博物馆和西雅图飞行博物馆在STEM教育领域的实践探索,归纳总结了美国博物馆在提供STEM学习资源,与学校STEM教育有效衔接,支持STEM教师专业发展,吸引家庭参与STEM教育,促进STEM教育公平等方面的经验,这些经验为我国发展非正式学习环境中的STEM教育,丰富STEM教育资源提供了良好的借鉴。

基于STEM理念的中学劳动教育项目式实践课程开发

劳动实践是劳动教育实现综合性育人功能的载体,具有内涵性、实践性、时代性和实用性的特征。STEM教育的项目式、跨学科性、实践性和情境性设计理念非常值得劳动教育实践课程设计所借鉴。基于STEM理念开展中学劳动实践项目式课程设计要关注课程中的项目任务情景设计、劳动实践过程设计、实践教学内容设计和项目学习过程的认知分析。项目式劳动实践课程与STEM课程存在明显差异,其目标在于培养劳动相关的多元素质,其项目侧重于劳动实践而非研究探索,且具有更广的适用范围。