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Adult neurogenesis:a real hope or a delusion?

neural Regeneration Research 2024年第1期19卷 6-15页

作者： Ghulam Hussain Rabia Akram haseeb Anwar Faiqa Sajid Tehreem Iman Hyung Soo Han Chand Raza Jose-Luis Gonzalez De Aguilar neurochemicalbiology and Genetics Laboratory(nGL) Department of PhysiologyFaculty of Life SciencesGovernment College UniversityFaisalabadPunjabPakistan Department of Physiology School of MedicineClinical Omics InstituteKyungpook National UniversityDaeguKorea Department of Zoology Faculty of Chemistry and Life SciencesGovernment College UniversityLahorePakistan InSERM U1118Mécanismes Centraux et Péripheriques de la NeurodégénérescenceStrasbourgFranceUniversitéde StrasbourgStrasbourgFrance

Adult neurogenesis,the process of creating new neurons,involves the coordinated division,migration,and differentiation of neural stem *** process is restricted to neurogenic niches located in two distinct areas of the brain:the subgranular zone of the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle,where new neurons are generated and then migrate to the olfactory *** has been thought to occur only during the embryonic and early postnatal stages and to decline with age due to a continuous depletion of neural stem ***,recent years have seen tremendous progress in our understanding of adult brain neurogenesis,bridging the knowledge gap between embryonic and adult ***,we discuss the current status of adult brain neurogenesis in light of what we know about neural stem *** this notion,we talk about the importance of intra cellular signaling molecules in mobilizing endogenous neural stem cell prolife *** on the current understanding,we can declare that these molecules play a role in targeting neurogenesis in the mature ***,to achieve this goal,we need to avoid the undesired proliferation of neural stem cells by controlling the necessary checkpoints,which can lead to tumorigenesis and prove to be a curse instead of a blessing or hope.

关键词： adult neurogenesis aging brain-derived neurotrophic factor dentate gyrus hippocampus neural stem cells neurotrophic factors notch oxidative stress stem cells subgranular zone

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Synthesis of size-controlled and dispersible Sm2Fe17n3 magnetic particles by reduction diffusion process using molten salt

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Journal of Rare Earths 2024年第11期42卷 2105-2111页

作者： Junhua Xi Zhi Yang Muhammad haseeb Yuanyuan Chen Xiaofeng nie Liying Cong Qiong Wu Enfeng Fu Hongguo Zhang Weiqiang Liu Ming Yue Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of Technology

The synthesis of size-controlled Sm2Fe17magnetic particles is a prerequisite for the fabrication of highperformance Sm2Fe17n3permanent magnetic ***,Sm2Fe17was synthesized using a costeffective reduction-diffusion *** calcium chloride molten salt was introduced to control the particle size and achieve a single phase of *** effects of reduction-diffusion reaction temperature and the amount of added calcium chloride on the phase constitution and microstructure of the final product of reduction-diffusion were systematically *** an appropriate amount of calcium chloride can effectively inhibit the overgrowth and sintering of the reduced *** employing the strategy of adding 20 wt% of calcium chlorides into the green compacts,we were able to successfully synthesize uniform Sm2Fe17particles that are well-dispersed,with an average size of 2.2 μ***,by combining the optimal reduction-diffusion conditions and the nitriding process,the hard magnetic Sm2Fe17n3material was successfully *** study could be useful for the development of high-performance Sm2Fe17n3magnetic materials utilizing reduction-diffusion technology.

关键词： Molten salt Permanent magnets Rare earths Reduction-diffusion Sm2Fe17n3

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Studies on the management of root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex of green gram, Vigna radiata cv ML-1108

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 736-742页

作者： haseeb Akhtar SHARMA Anita SHUKLA Prabhat Kumar Department of Plant Protection Faculty of Agricultural Sciences Aligarh Muslim UniversityAligarh-202002 IndiaDepartment of Plant Protection Faculty of Agricultural Sciences Aligarh Muslim UniversityAligarh-202002 IndiaDepartment of Plant Protection Faculty of Agricultural Sciences Aligarh Muslim UniversityAligarh-202002 India

Studies were conducted under pot conditions to determine the comparative efficacy ofcarbofuran at 1 mg a.i./kg soil, bavistin at 1 mg a.i./kg soil, neem （Azadirachta indica） seed powder at 50 mg/kg soil, green mould （Trichoderma harzianum） at 50.0 ml/kg soil, rhizobacteria （Pseudomonas fluorescens） at 50.0 ml/kg soil against root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex on green gram, Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared carbofuran and A. indica seed powder increased plant growth to untreated inoculated plants. Analysis of data showed that and yield significantly more in comparison to bavistin and P. fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus, A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.

关键词： Meloidogyne incognita Fusarium oxysporum Disease complex Management Vigna radiata

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Screening of field pea (Pisum sativum) selections for their reactions to root-knot nematode (Meloidogyne incognita)

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第3期7卷 209-214页

作者： SHARMA Anita haseeb Akhtar ABUZAR Syed Department of Plant Protection Faculty of Agricultural Sciences Aligarh Muslim University Aligarh-202002 India

Pot studies were carried out to evaluate the reactions of 23 selections of field pea （Pisum sativum） against Meloidogyne incognita （2000 freshly hatched juveniles （J2）/pot）. Experiment was conducted under greenhouse conditions （（24.7±3） ℃ and （62±7）% RH） and terminated 45 d after inoculation. The roots of all the selections were assessed to determine root-knot indices （RKI） on a 0-4 scale. Out of 23 selections HFP-990713, Pant P-25, and HFP-0129 were resistant; Pant P-2005, nDP-2 and Pant P-42 were tolerant; LFP-305, HFP-8909, HFP-4, HUP-31, HFP-0128, Pant P-31, Pant P-40, LFP-363, and HFP-0118 were moderately resistant; HFP-0110, HUDP-28, HUDP-15, HUDP-27, HUP-30, HUP-2 and HUDP-26 were moderately susceptible; and only Ambika was susceptible to M. incognita. It was observed that reproduction of nematode was favored on tolerant and susceptible cultivars but inhibited on resistant ones. Strong negative correlation was observed between the total fresh and dry plant weights and the root-knot index. The selection Pant P-42 showed highest tolerance among all the selections tested and can be recommended for field trials, whereas, selection Ambika showed highest susceptibility and should be avoided.

关键词： Pisum sativum Meloidogyne incognita Resistance

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In vivo cardiac pacemaker function of differentiated human mesenchymal stem cells from adipose tissue transplanted into porcine hearts

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World Journal of Stem Cells 2020年第10期12卷 1133-1151页

作者： Fabrice F Darche Rasmus Rivinius Ann-Kathrin rahm Eva Köllensperger Uwe Leimer Günter Germann Miriam Reiss Michael Koenen Hugo A Katus Dierk Thomas Patrick A Schweizer Department of Cardiology Medical University Hospital HeidelbergHeidelberg D-69120Germany DZHK(German Centre for Cardiovascular Research) Partner Site Heidelberg/MannheimUniversity of HeidelbergHeidelberg D-69120Germany HCR(Heidelberg Center for Heart Rhythm Disorders) Department of CardiologyMedical University Hospital HeidelbergHeidelberg D-69120Germany Department of Plastic Surgery ETHIANUM Klinik HeidelbergHeidelberg D-69115Germany Department of Molecular neurobiology Max-Planck-Institute for Medical ResearchHeidelberg D-69120Germany

BACKGROUnD Mesenchymal stem cells(MSC)modified by gene transfer to express cardiac pacemaker channels such as HCn2 or HCn4 were shown to elicit pacemaker function after intracardiac transplantation in experimental animal *** MSC derived from adipose tissue(haMSC)differentiate into cells with pacemaker properties in vitro,but little is known about their behavior after intracardiac *** To investigate whether haMSC elicit biological pacemaker function in vivo after transplantation into pig *** haMSC under native conditions(nhaMSC)or after pre-conditioning by medium differentiation(dhaMSC)(n=6 pigs each,5×106 cells/animal)were injected into the porcine left ventricular free *** receiving PBS injection served as controls(n=6).Four weeks later,total atrioventricular(AV)-block was induced by radiofrequency catheter ablation,and electronic pacemaker devices were implanted for backup stimulation and heart rate *** rate and rhythm of pigs were evaluated during a follow-up of 15 d post ablation by 12-lead-ECG with heart rate assessment,24-h continuous rate monitoring recorded by electronic pacemaker,assessment of escape recovery time,and pharmacological challenge to address catecholaminergic rate ***,hearts were analyzed by histological and immunohistochemical *** In vivo transplantation of dhaMSC into the left ventricular free wall of pigs elicited spontaneous and regular rhythms that were pace-mapped to ventricular injection sites(mean heart rate 72.2±3.6 bpm;n=6)after experimental total AV *** rhythms were stably detected over a 15-d period and were sensitive to catecholaminergic stimulation(mean maximum heart rate 131.0±6.2 bpm;n=6;PnhaMSC or PBS presented significantly lower ventricular rates(mean heart rates 47.2±2.5 bpm and 37.4±3.2 bpm,respectively;n=6 each;Pnd exhibited little sensitivity towards catecholaminergic stimulatio

关键词： Biological cardiac pacemaker Mesenchymal stem cells Differentiation Animal model Cell transplantation Stem cell therapy

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火灾下受弯钢筋混凝土梁损伤规律研究

火灾下受弯钢筋混凝土梁损伤规律研究

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作者：韩石（haseeb Ul Hassan）中南大学

学位级别：硕士

火灾作为隧道运营过程中的主要灾害,不但会降低隧道整体的承载力和安全性,还会威胁群众生命财产安全。考虑到隧道多为钢筋混凝土结构,在受到火灾时,钢筋混凝土结构的损伤情况将会直接影响隧道火灾救援及灾后修复工作。因此,研究温度与... 详细信息

火灾作为隧道运营过程中的主要灾害,不但会降低隧道整体的承载力和安全性,还会威胁群众生命财产安全。考虑到隧道多为钢筋混凝土结构,在受到火灾时,钢筋混凝土结构的损伤情况将会直接影响隧道火灾救援及灾后修复工作。因此,研究温度与弯矩耦合作用下钢筋混凝土结构的受力和损伤情况。但由于足尺钢筋混凝土结构的火灾试验的操作难度较高、可重复性不强,通过试验得出结构的热力耦合损伤规律具有一定的限制。随着计算机仿真模拟的不断进步,数值模拟所得结果已经能够很好地贴近于试验结果,同时又因其具有不受试验成本和试块尺寸限制的优势,弥补了试验的不足。因此,本文以足尺钢筋混凝土梁为研究对象,采用试验和数值模拟相结合的方法,通过试验测得梁的基础温度场分布及变形情况,将试验结果与数值模拟结果进行对比分析,验证数值模拟结果的准确性,而后通过ABAQUS建立数值模拟模型,改变模型的受火时间和弯矩大小,研究钢筋混凝土梁在火灾和弯矩耦合下的温度场分布及结构变形规律。本试验的燃烧炉为中南大学防灾科学与安全技术研究所自行研制的大型电阻炉,该试验炉的炉膛净空为宽420mm,高470 mm。试验炉体总长3700mm,超过试件截面高度的4倍,可使\试件受到一致温度场的作用。试验炉由炉箱结构、加热元件、隔热层、附件组成。炉箱结构由角钢和扁钢焊接成骨架,外面覆盖薄钢板,用以支撑并固定炉瓦和隔热材料,成为一个刚性的整体。加热元件的主要部件是炉瓦,选用耐火材料制成的定型井式炉瓦加工而成,在炉瓦的外侧至炉箱之间,用硅酸铝耐火纤维保温材料填充,作为隔热层。炉箱两端的下方有槽钢相连,共有4个吊环,便于吊装和悬挂;炉箱一侧的上部有电阻丝接线端,可接入电源;炉箱中部有3个温度测控,可以插入热电偶,以便实时监控温度,温度控制柜中采用了继电器控制电路。电源通过控制柜接入试验炉,构件的试验炉和温度控制柜在制作完成后一起使用,能测量到炉内各个热电偶的升温曲线,多次的高温试验的升温曲线恒定,且再现性好。论文的研究工作主要从以下几个方面开展:一、钢筋混凝土试验梁的制备与加载、测温试验。根据已有的研究和理论分析,影响钢筋混凝土梁火灾损伤程度的主要因素有构件初始荷载、燃烧时间、构件配筋及保护层厚度等。由于试验条件和时间的限制,本次试验的对比因素只考虑初始荷载、燃烧时间、配筋率的影响。本试验共设计钢筋混凝土梁7根,梁的截面尺寸为:宽250 mm,高400mm,梁长4800mm,采用单筋矩形截面。纵向受力钢筋采用直径为22mm,HRB400级的热轧钢筋,数量依据试验需要进行调整;假设构件处于室内正常环境,保护层厚度为25mm;混凝土强度等级为C40;架立钢筋采用2根直径为10mm,HPB235级热轧钢筋;箍筋采用四边形封闭箍筋,直径为8mm,HPB235级热轧钢筋。混凝土强度按水泥:水:砂:碎石=1:0.56:2.15:4.06的配合比设计,水泥采用湖南省韶峰水泥集团有限公司生产的强度等级为42.5的普通硅酸盐水泥;砂采用湘江河砂(中砂);卵石采用湘江的卵石、最大粒径为25mm。首先试验梁按要求就位,采用千斤顶对试验梁加载。试验采用分级加载,每级荷载为20k n,且加完一级荷载后,稳定2分钟再读数。将高温冷却后的钢筋混凝土梁进行静力加载试验,研究其破坏形式以及剩余承载力的大小,试验过程与未受高温的梁静力加载试验相似。为测定高温试验时梁截面的内部温度场分布,在其内部预埋铜管以插入热电偶。构件制作时,在每根根梁的1/4、跨中和3/4截面内部均预埋了铜管。并且1/4截面的铜管预埋在第一根钢筋上面,埋置5根,高度均匀分配,同样,3/4截面的铜管预埋在第二根钢筋上面,埋置5根,高度均匀分配,跨中截面的铜管预埋在跨中,埋置8根。二、构建钢筋混凝土梁的数值模拟模型。考虑到试验结果存在一定的离散型及随机性,较难通过定量调整影响梁损伤结果的参数,获取钢筋混凝土梁的损伤规律。将试验结果与数值模拟结果进行对比分析,验证数值模拟结果的准确性,而后通过数值模拟调整受火时间及荷载数值,可得出钢筋混凝土梁在热力耦合作用下的变形损伤规律,为合理判定火灾后钢筋混凝土构件的损伤评估及修复工作提供依据。ABAQUS是一套功能强大的有限元模拟软件,可以对复杂的固体力学问题及结构力学系统进行分析,对单一零件及多物理场的力学问题均适用,尤其善于处理高度非线性模拟问题。ABAQUS丰富的单元库可以模拟任意几何形状,其内含有的材料模型库可以模拟大多数典型的工程材料性能,如混凝土、可压缩泡沫以及地质材料如土壤和岩石等。钢筋混凝土梁模型的建立分为八个模块,具体如下:(1)创建部件空间钢筋混凝土连续梁,模型是由混凝土、纵筋、箍筋和刚性垫块等部件组成,所有部件均采用C3D8单元。混凝土梁的尺寸为宽250 mm,高400mm,梁长4800mm,纵向受力钢筋采用直径为22mm,箍

关键词：钢筋混凝土梁火灾弯矩热力耦合

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河流盆地的硅持留:对沿海及海洋环境生物地球化学和水生食物网的深远影响

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AMBIO－人类环境杂志 2000年第1期29卷 45-50页

作者： Christoph Humborg Daniel J. Conley Lars rahm Fredrick Wulff Adriana Cociasu Venugopalan Ittekkot 张国梁海洋系统生态学罗马尼亚海洋研究所海洋化学和海洋学研究室生物地球化学和海洋化学

河流的拦截调蓄和河流盆地的富营养化大大地降低了溶解态硅(DSi)向黑海和波罗的海的输入。尽管流域中的人为输入可以补偿湖泊和水库中去除的n和P,但却不能补偿DSi。看来河流径流中营养物组成(DSi:n:P比)的变化是黑海浮游植物种类构成戏... 详细信息

河流的拦截调蓄和河流盆地的富营养化大大地降低了溶解态硅(DSi)向黑海和波罗的海的输入。尽管流域中的人为输入可以补偿湖泊和水库中去除的n和P,但却不能补偿DSi。看来河流径流中营养物组成(DSi:n:P比)的变化是黑海浮游植物种类构成戏剧性转变的原因。在波罗的海,DSi浓度和DSi:n比从60年代以来一直在下降,表现为春天旺发的硅藻比例下降,而鞭毛藻却增加了。这对黑海和波罗的海沿海生物地球化学循环和食物网结构的影响可能是深远的,因为它表明,随着以调蓄河水为目的的水坝建设的不断增加,河流输送的DSi的下降可能正在世界范围发生。

关键词：海洋环境河流拦截水生食物网硅富营养化

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