癌症“种子土壤说”新论

\"种子土壤\"理论最初被应用于肿瘤转移相关学说,文章根据癌症的发生、发展和转移等规律,从另一个全新的角度来定义\"种子土壤说\",呈现直观又形象的癌症解读,并且将这种理论应用于指导癌症的诊断、预防和治疗,体现出在未来中医和西医的融合必将会是医学发展的大势所趋。厦门市重大科技计划项目(No.3502Z20100006);;厦门市科技计划高校创新项目(No.3502Z20153027)~

Formation and solving for the micro-waves of fly-cut surface introduced by spindle error

为分析超精密飞切机床加工表面微波纹的形成机理,研究了主轴回转误差信息提取与表面形貌仿真技术,获取微波纹误差来源并研究解决方案。首先,在超精密飞切机床主轴上搭载五通道在线电容位移检测系统,并对采集到的信号进行误差分析提取。然后,建立飞切加工表面微观形貌三维仿真模型,仿真分析主轴误差引入的加工表面微波纹,并与表面检测结果比对确定误差来源。最后,通过调整主轴电机控制系统抑制该误差。三维仿真和实测结果相吻合,证实超精密飞切机床主轴转速波动导致的回转误差造成了工件表面1 Hz左右的规律性条纹,对主轴转速控制系统进行数字化改造后,基本消除了该因素导致的表面微波纹,表面粗糙度从5 nm以上抑制到2 nm左右,PV值优于10 nm。超精密飞切机床主轴转速波动会对飞切加工表面微观形貌以及表面粗糙度产生显著影响,需至少控制在0.5 r/min以内。In order to find out the formation mechanism of micro-waves on the fly-cut surface,the spindle motion error was sampled and a 3D topography simulation model was compiled. Firstly,a nano-class testing and evaluation system was established on the fly cutting machine,the displacement data was sampled and the spindle motion error was analyzed.Then a 3D surface profile topography simulation model was established to analyze the micro-waves caused by the spindle motion error. The simulated surface was compared with the measured surface to find out the error sources. Finally,the characteristics of spindle were improved by adjusting the control system of the spindle motor. The simulated 3D surface profile topography was similar to that of the measured profile,which verified that the macro-waves was caused by the undulate of the spindle speed. When the spindle characteristics was improved,the macro-waves caused by the spindle motion error almost disappeared,and the surface roughness reduced from more than 5 nm to 2 nm. It is thus concluded that the undulate of ultra-precision fly cutting machine spindle speed causes macro-waves on the work-piece surface,and the undulate spindle speed must less than 0. 5 r / min.基金项目:高档数控机床与基础制造装备《强激光光学元件超精密制造关键装备研制》(2013ZX04006011-102-001

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

铜基廉价催化剂的火焰合成及甲烷催化特性研究

本文基于预混滞止弱旋火焰系统,以溶于水或乙醇的廉价硝酸盐为前驱物,采用“一步”的雾化火焰方法来合成铜基催化剂纳米颗粒。采用TEM、XRD等分析了合成颗粒的形貌及物相态,进而考察了该催化剂在甲烷催化氧化反应中的催化活性。根据TEM结果,发现乙醇做溶剂时所合成的氧化铜颗粒具有颗粒直径小且结晶度较好的特点。实验结果表明,10 nm氧化铜颗粒体现出良好的甲烷催化性能,但掺杂氧化铝后,铜基催化剂对甲烷的催化性能有所下降,其原因可归结为氧化铝对氧化铜的覆盖作用导致其有效比表面积降低

铜基廉价催化剂的火焰合成及甲烷催化特性研究

本文基于预混滞止弱旋火焰系统,以溶于水或乙醇的廉价硝酸盐为前驱物,采用“一步”的雾化火焰方法来合成铜基催化剂纳米颗粒。采用TEM、XRD等分析了合成颗粒的形貌及物相态,进而考察了该催化剂在甲烷催化氧化反应中的催化活性。根据TEM结果,发现乙醇做溶剂时所合成的氧化铜颗粒具有颗粒直径小且结晶度较好的特点。实验结果表明,10 nm氧化铜颗粒体现出良好的甲烷催化性能,但掺杂氧化铝后,铜基催化剂对甲烷的催化性能有所下降,其原因可归结为氧化铝对氧化铜的覆盖作用导致其有效比表面积降低

电势型固体电解质氧传感器电极制备及响应性能

研究了电极涂覆面积、电极涂覆位置和电极催化剂用量对电势型固体电解质氧传感器响应特性的影响。结果表明：电极涂覆面积和电极涂覆位置的变化会导致传感器电极极化电阻和电解质电阻的变化,但对传感器的响应特性却几乎没有影响;一定范围内电极催化剂载量的增加有助于减小电极表面电阻、电极极化电阻以及传感器的电解质电阻,但同时也会增加电极中气体的传质阻力。因此制作电极时,催化剂的载量需要优化。一般以传感器电极表面电阻刚好小于1Ω时的载量为最佳电极催化剂载量

The Denitrification Rate and Its Influence Factors in the Surface Sediment of Yellow River Estuary in Autumn

用乙炔抑制法和现场静态箱法对黄河口附近海域秋季的反硝化速率进行了研究,该海域反硝化速率在3.8~19.3μmol/(m2.h)之间,平均10.27μmol/(m2.h)。影响其反硝化速率的主要因素为反硝化细菌的数量。黄河口的反硝化速率低于珠江口和长江口海域。 &nbsp

电势型固体电解质氧传感器电极制备及响应性能

研究了电极涂覆面积、电极涂覆位置和电极催化剂用量对电势型固体电解质氧传感器响应特性的影响。结果表明:电极涂覆面积和电极涂覆位置的变化会导致传感器电极极化电阻和电解质电阻的变化,但对传感器的响应特性却几乎没有影响;一定范围内电极催化剂载量的增加有助于减小电极表面电阻、电极极化电阻以及传感器的电解质电阻,但同时也会增加电极中气体的传质阻力。因此制作电极时,催化剂的载量需要优化。一般以传感器电极表面电阻刚好小于1Ω时的载量为最佳电极催化剂载量