珠江口外陆架区溶解态~(223)Ra和~(224)Ra的季节性分布及影响因素分析

该文调查了珠江口外陆架区一个断面上223rA和224rA随季节变化的活度分布及其影响因素。夏季珠江径流量最大,故在距离河口最近的A9站位表层镭活度夏季高于其他季节。但夏季珠江冲淡水扩散方向偏离本研究的断面方向,故其整个剖面平均活度小于沉积物贡献非常大的秋季的垂向平均活度。春季,珠江径流量较大,但其扩散方向偏离断面方向,故春季各个站位的垂向平均活度均小于其他季节。珠江口外陆架区溶解态223rA和224rA的分布受控于沉积物、珠江径流量及珠江冲淡水的扩散方向。973计划(编号:2009CB421204); 国家自然科学基金青年基金项目(编号:41006041); 高等学校博士学科点专项科研基金资助课题(20090121120022

重金属Cd对桐花树土壤酶活性的影响

采用土培模拟方法研究了不同浓度Cd (0～50 mg/kg)对桐花树(Aegiceras corniculatum )土壤酶活性的影响. 试验 结果表明:低浓度Cd (0. 5 mg/kg)胁迫,可刺激脲酶的活性;在高浓度Cd (20～50 mg/kg)处理条件下,脲酶、蛋白酶、蔗糖 酶、过氧化物酶活性均受到不同程度的抑制,最大抑制率均达到25%以上; Cd处理对过氧化氢酶活性无显著影响. 相关 分析表明, Cd处理浓度与土壤酶活性间均存在显著负相关关系,相关程度为:脲酶>蛋白酶>过氧化物酶>蔗糖酶>过 氧化氢酶;脲酶、蛋白酶、蔗糖酶、过氧化物酶4种酶的活性间呈显著正相关,表明这4种酶对Cd胁迫有相似的适应性. 脲酶对Cd的影响作用最为敏感,建议用脲酶作为Cd对桐花树湿地污染的指示酶

Studies on the Mechanism of Variations of Hybrids of Domesticated Silkworm and Eri Silkworm ——RAPD Analysis of Genome

采用24种随机引物，对以蓖麻蚕精子进行人工授精得到的家蚕后代中的3个稳定变异品系及其亲本的基因组进行了rAPd检测，结果显示，在变异品系的rAPd图谱中，不仅存在大量与母本相同的“亲本带”，同时还出现了不同数量与母本不同的“变异带”，包括“非亲本带”、“缺失带”及个别仅与父本相同的“目的带”，从分子水平上揭示了变异品系存在着明显的“偏母性”与“变异性”特点。Twenty-Four random primers were used to analyze the genomes of three descendant strains with steady hereditable variation produced Form domesticated silkworm by artiFicial insemination with sperms of eri silkworm.The results show that in the RAPD patterns there are many ampliFied bands called“ parental bands”which are similar to those of the Female parent.At the same time, there appears varied amount of ampliFied bands called “variant bands” that are diFFerent From those of the Female parent.The variant bands include non-parental-bands, lost-bands and several “expected-bands” which only shared with the male parent.This research reveals the signiFicant matrocliny and variation in the descendant strains at the molecular level.国家自然科学基

RAPD Analysis of Hereditary and Variation of Domesticated Silkworm Generated by Introduction of Eri Silkworm DNA

借助于精子介导，在家蚕受精的过程中将蓖麻蚕dnA转入家蚕卵内，从它们后代获得了新的变异品系。本文采用rAPd技术对这些品系基因组dnA进行了分析。结果表明，所用50种10MEr随机引物中有49个检测出dnA的多态性，统计分析图谱中各类扩增带，其中变异品系与其相应受体的差异带占其总带数的26~37%，提示外源dnA导入受体后引起后代基因组的显著变异，并对这些变异的意义进行了讨论。With the aid of domesticated silkworm sperms, eri silkworm DNA was transFerred into domesticated silkworm eggs during insemination, and variant strains were obtained From the progenies.Genomes of three new strains were analyzed using RAPD assay.Polymorphic Fingerprints were obtained From 49 out of 50 primers.DiFFerent kinds of ampliFied bands in RAPD patterns were calculated and analyzed, the variant bands between variants and their recipients counted For 26～37% of the total bands of each variant.The results indicated that exogenous DNA introduced into recipients induced remarkable variation in progeny genomes.The signiFicance of the variation was discussed.国家自然科学基

21世纪图书馆学研究方法体系探析

通过对２１世纪图书馆学研究方法体系发展轨迹的梳理，提出在新的背景和环境下，现有的层次论、过程论、 三维论等图书馆学研究方法体系已不适应图书馆学理论发展的需要，并初步架构合理的图书馆学方法体系

Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25

阿尔茨海默病（Alzheimer’s disease, AD）是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征（Down’s syndrome, DS）是早发型阿尔茨海默病的一个重要风险因素，作为最常见的智力障碍遗传疾病，厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点，并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能，缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成，厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作，王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持，清华大学董晨教授提供了Usp25基因敲除小鼠，厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao). 该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持

落实科学发展观,促进我国高等教育的发展

科学发展观的内涵极其丰富,以人为本,全面、协调、可持续的发展是它的主要内涵。科学发展观是指导我国高等教育发展的指南。新时期的高等教育,必须牢固树立和认真落实科学发展观,确立新型的高等教育发展目标,优化高等教育的结构与管理,确立学生在教学活动中的主体地位,建设一支高水平的师资队伍,才能实现高等教育又快又好的发展

Estimation of submarine groundwater discharge into the Sanya River estuary in the winter using ~(223)Ra and ~(224)Ra as tracers

对三亚河口两种短半衰期溶解态镭同位素(223 rA和224 rA)活度随盐度的分布进行了调查,并估计了其源汇项。调查发现,三亚河口中溶解态223 rA和224 rA的分布范围分别是:1~8dPM/100l和13~281dPM/100l。在低盐度区,223 rA和224 rA的活度都随着盐度的增大而增大,至中盐度时达到最大值,之后随盐度的继续增加而逐渐减小。其活度主要受控于放射性衰变、涨潮退潮、颗粒物解吸、沉积物扩散和海底地下水排放。利用同位素比值法和质量平衡模型计算得到三亚河口水体的平均近似水龄为4d,河口中68%的镭来自于海底地下水排放的贡献,海底地下水排放流量为1.14x106 M3/d,是三亚河流量的2倍。We investigated distributions of the two short-lived radium isotopes in the dissolved phase in the Sanya River estuary.The activities of 223 Ra and 224 Ra were in the range of 1to 8dpm/100Land 13to 281dpm/100L,respectively.Their activities increased with salinity rising in the low salinity zone,and reached the maxima in the mid salinity zone;however,the activities decreased with the salinity getting even higher.In the estuary the activity of radium is controlled by such factors as radioactive decay,tide input and output,desorption from suspended particles,sediments diffusion and submarine groundwater discharge.Using the activity ratio of the two isotopes and the mass-balance model,the average apparent age in the Sanya River estuary was estimated to be 4d.More than 68% of radium sources were contributed by submarine groundwater discharge.The submarine groundwater discharge flux into the Sanya River estuary was 1.14×106 m3/d,about two times of the Sanya River discharge.国家自然科学基金资助项目(41006041); 高等学校博士学科点专项科研基金资助项目(20090121120022

刚性接触网悬挂结构刚度识别方法

接触网-受电弓系统是列车运行驱动力的来源。相比于柔性接触网,刚性接触网因其净空低、坚固耐用、抗风性好等优点一直是当前研究的热点。针对刚性接触网悬挂结构的传统建模方法是将其等效成弹簧结构,并根据能量守恒对其刚度进行等效。基于此,提出一种基于遗传算法的利用刚性接触网的实验模态信息识别建模参数的新方法,建立刚性接触网仿真模型新的验证和修改方法,设计若干常见工况对本方法的可行性进行验证。研究结果表明:本方法因其对结构刚度的敏感性,不仅可识别刚性接触网悬挂结构刚度,而且当悬挂结构损伤时,能够识别到悬挂结构弹簧的损伤位置和实际有效刚度值。经验证在常见工况下,该方法识别到刚度值的平均相对误差低于5%