Research of chemical exchange saturation transfer in brain

化学交换饱和转移(chemical exchange saturation transfer,CEST)成像是在磁化传递及化学交换理论基础上发展起来的一种磁共振成像新方法,其扩展了磁共振分子影像新领域,但还处于研究阶段。其以细胞内物质为内源性对比剂,通过水信号间接检测代谢物信息,进行组织的酸碱度成像及其各种代谢物成像。本文主要探讨MRI领域中与水相关的化学交换饱和转移现象,阐述其原理、研究现状及其在不同场强磁共振仪上脑部疾病的应用。Chemical exchange saturation transfer(CEST) imaging is a new method for magnetic resonance imaging theory of exchange in the magnetization transfer and chemical, the expansion of the new field of molecular magnetic resonance imaging,but it's still in the research stage. The intracellular substances as an endogenous contrast agent, through the indirect detection of metabolite water signal information for tissue p H imaging and imaging of various metabolites. This paper mainly discusses the chemical and water exchange in the field of MRI saturation transfer phenomenon,expounds the principle, research status and the application in brain diseases used the different field strength clinical MRI scanner.2014年厦门市科技局科技惠民计划项目(编号:3502Z20144052)~

Biochemical characters of forest soils at Wuyishan Mountain.

研究了武夷山自然保护区森林土壤生化特性.结果表明，不同生境土壤呼吸作用、纤维分解作用和硝化作用等3项生化强度有明显差异，先峰岭（常绿阔叶林）＞大竹岚（毛竹林）.同一生境中的不同小生境3项生化强度的差异也很显著，尤其是呼吸作用强度，落叶层＞腐殖层＞土壤层；纤维分解作用强度，腐殖层＞落叶层＞土壤层；硝化作用强度，土壤层＞落叶层＞腐殖层.无论那一种生境3项生化强度之间，呼吸作用强度与纤维分解作用强度有一定相关性，而硝化作用强度与前两项未显示相关.不同生境土壤蔗糖酶、纤维素酶和蛋白酶等活性显著不同，大竹岚＞先峰岭.同一生境中的不同小生境3种酶活性随土壤剖面深度而降低；蔗糖酶是各生境中活性最大酶类，变化较剧；纤维素酶和蛋白酶则活性较小，变化较缓和.Studies on the biochemical characters of forest soils in Wuyishan Mt.Natural Reserve show that the rates of soil respiration, cellular decomposition and nitrification differed obviously with habitats.Soils under broad leaved evergreen forest ( Castanopsis eyrei ) at Xianfengling had higher rates than those under moso bamboo forest ( Phyllostachys heterocyca var. pubescens ) at Dazhulan.The three rates at each habitat also significantly differed with microhabitats: for respiration rate, litter layer>humus layer>soil layer; and for nitrification rate, soil layer>litter layer>humus layer; for cellular decomposition rate, humus layer>litter layer>soil layer.Among the three rates at each hibitat, there existed a definite relationship between respiration rate and cellular decomposition rate, while the nitrification rate was independent of the other two.The activities of sucrase, celluase and proteinase varied with different habitats, which were higher at Dazhulan than at Xianfengling, and decreased with increasing soil depth.Among the three enzymes, sucrase had the highest activity at all microhabitats, and the variation of its activity was greater.福建省自然科学基金;武夷山自然保护区管理局资助项

发酵罐高密度培养盘基网柄菌

利用SIH合成培养基,在7 L发酵罐培养盘基网柄菌.培养147 h后,细胞密度达到4.0×107mL-1,为在复杂培养基上所能达到的细胞密度的2~4倍.培养过程中葡萄糖的消耗量为6.7 g/L,产氨浓度达0.88 g/L.对培养基中的氨基酸分析表明,赖氨酸、色氨酸、甲硫氨酸和苯丙氨酸消耗较快,显示SIH培养基的氨基酸成分还可进一步优化.采用基于Monod生长动力学的半经验模型可很好模拟细胞生长和底物消耗,并估计出动力学参数μm ax=0.115 h-1,Nm ax=6.0×107mL-1.本研究为进一步优化合成培养基和为利用这一新型真核表达系统大规模生产重组异源蛋白奠定了基础

Study of Parameters of Neutron-Irradiated Single Crystal Silicon

在不同温度和红外光照下，测量了经中子辐照的单晶硅表面光电压，确定了其深能级的位置和少子扩散长度；由双能级复合理论，推导了中子辐照单晶硅的深能级复合中心和寿命的计算公式；计算了热中子辐照和高能中子辐照单晶硅后的深能级密度、费米能级和其他有关重要参数。The photovoltage spectra of neutron-irradiated single crystal silicon under inFra-red illumination and at low temperatures are measured.The deep level and minority carrier diFFusion length are determined.By the double-level recombination model,the statistics Formulas of the deep level and liFetime are derived For neutron-irradiated single crystal silicon.Some important parameters of the silicon irradiated with high energy and thermal neutron are calculated respectively.国家自然科学基

Biodiversity of the ectomycorrhiza on the rare and endangered tree species Tuga chinensis tchekiangensis(Flous) Cheng in Wuyishan Nature Reserve

对武夷山国家级自然保护区残遗与濒危树种南方铁杉植物群落历经了6年的调查,共采集了123种外生菌根,经显微与超显微技术鉴定了84种,这一结果是迄今为止已发表的,在同一树种中菌根类型最多的记录.它不仅证明了武夷山地区的菌物区系由于处于东西相连,南北贯通的位置上,而且从区系成分上据有温热两带俱全的特点,因而形成生物多样性,并从共生菌的角度再度揭示了物种协同进化的规律.Systematic investigation was made on ectomycorrhizae in the woods of a variety of Tsuga chinensis,tchekiangensis(Flous) Cheng,in Wuyishan Nature Reserve in the past six years.During that period,120 ectomycorrhiza samples were collected and 84 types identified by analysing their macro-micro-and ultrastructure.This is the first time that so many types of mycorrhiza in the forests of the species are reported on.This result has proved Wuyishan's geographical position at the cross where a fungi growing area links the east and west,south and north.Thus the region owns the characteristics of both the temperate and the subtropical zone and it is thus such peculiarity whereby its biodiversity is created.Moreover,considering the results of this investigation in the regard of symbiosis between plants and fungi,their co-evolution is ascertained once more.国家自然科学基金资助项目(39770004);; 福建省自然科学基金资助项目(C97003,D0410002

类泛素蛋白及其中文命名

泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

Soluble TREM2 ameliorates pathological phenotypes by modulating microglial functions in an Alzheimer's disease model

阿尔茨海默病（Alzheimer’s Disease, AD）是一种以渐进性认知功能丧失为主要特征的神经退行性疾病，是最为常见的老年痴呆类型。随着全球人口老龄化的加剧，AD正在成为二十一世纪最大的疾病之一。该研究首次揭示sTREM2在AD中具有重要的保护功能，提出sTREM2或可用于AD治疗的新观点，同时也进一步佐证了小胶质细胞在AD治疗中的核心作用，研究为AD等神经退行性疾病的防治开辟了新思路、提供了新靶点。 厦门大学医学院博士后钟力和硕士研究生徐颖为论文共同第一作者，陈小芬教授和卜国军教授为该论文的共同通讯作者。厦门大学的文磊、孙灏、卓仁恭等教授和美国Sanford-Burnham-Prebys医学研究所的许华曦教授共同参与了该项目的研究。【Abstract】Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial surface receptor genetically linked to the risk for Alzheimer’s disease (AD). A proteolytic product, soluble TREM2 (sTREM2), is abundant in the cerebrospinal fluid and its levels positively correlate with neuronal injury markers. To gain insights into the pathological roles of sTREM2, we studied sTREM2 in the brain of 5xFAD mice, a model of AD, by direct stereotaxic injection of recombinant sTREM2 protein or by adeno-associated virus (AAV)-mediated expression. We found that sTREM2 reduces amyloid plaque load and rescues functional deficits of spatial memory and long-term potentiation. Importantly, sTREM2 enhances microglial proliferation, migration, clustering in the vicinity of amyloid plaques and the uptake and degradation of Aβ. Depletion of microglia abolishes the neuroprotective effects of sTREM2. Our study demonstrates a protective role of sTREM2 against amyloid pathology and related toxicity and suggests that increasing sTREM2 can be explored for AD therapy.Research by the authors was supported by grants from the National Natural Science Foundation of China 81370459, 31400914 (to X.C.), 81701079 (to L.Z.), 81373999, 81774377 (to L.W.), and 81601227 (to R.Z.), grants from the Natural Science Foundation of Guangdong Province 2016A030306005 (to X.C.), 2016A030310371 (to R.Z.), grants from the Fundamental Research Funds for the Central Universities 20720180055 (to X.C.), grants from the Alzheimer's Association AARG-18-56635 (to X.C.), and C4C-15-369446 (to H.X.). NIH grants RF1AG056130 (to G.B. and H.X.), R01AG035355 (to G.B.), R37AG027924 (to G.B.), and RF1AG056114 (to H.X.), grants from the Postdoctoral Science Foundation of China 2016M600503 and 2017T100469 (to L.Z.), a grant from the Tanz Family Funds (to H.X.), and a grant from the Natural Science Foundation of Fujian Province 2016J05203 (to R.Z.).该工作得到国家自然科学基金、厦门大学校长基金、广东省自然科学杰出青年基金、美国阿尔茨海默氏症协会基金和中国博士后科学基金等的资助

液相不溶型合金复合组织自形成驱动力的解析

利用Becker提出的计算界面能的方法 ,计算了液相不溶体系中两液相的界面能 ,并基于Gibbs Thomson关系式 ,对整个析出液相和基体液相之间的表面能进行积分 ,得到了在冷却过程中作用在液滴上指向试样中心的力 ,它是半径和温度梯度的函数 .除了上述的作用力外 ,重力和浮力也同时作用在液滴上 .这些力的合力是形成该类型复合组织的主要原因 .该方法应用到Fe Cu合金系 ,进行了计算 ,与实验结果符合得很好.国家自然科学基金(批准号:50271027); 福建省国际合作(2002I018); 福建省自然科学基金(E0310023); 福建省青年创新基金(2002J010)资助项目