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The effect of gallium nitride on long-term culture induced aging of neuritic function in cerebellar granule cells
No full textNeurons Cultured on Gan and Is Associated with Synapsin I and Map2 Expression
No full textIn this work, the behaviors of cerebellar granule neurons prepared from 7 -day-old Wistar rats on GaN, GaAs, and silicon were investigated. We believe that this is the first time that the GaN has been used as a substrate for neuron cultures to examine its effect on cell response in vitro. The GaN surface structure and its relationship with cells were examined by scanning electron microscopy ( SEM), immunofluorescence lactate dehydrogenase ( LDH). Compared with silicon used for most neural chips, neurons seeded on GaN were able to form an extensive neuritic network and expressed very high levels of synapsin I coincident with the neurite outgrowth. LDH assay indicated that GaN improve neuron survival better than silicon and GaAs. Between in seven-day and day 15-cultured neurons, these results are consistent with the influence of GaN, in the regulation of neuronal adhesion, neuritic plasticity and survival, within in vitro. The favorable biocompatibility characteristics of GaN can be used to measure electric signals from networks of neuronal cells in culture to make it a possible candidate for use in a microelectrode array
Development of GaN chips to culture cerebellar granule neurons，neural stem/precursor cells and PC12 cells
No full text神經細胞在體內生長須靠neurotrophic factors 及神經傳入的刺激才能良好生存。小腦顆粒神經細胞為高度均一的神經培養模式，一直被廣泛應用於神經細胞生長發育及凋亡機制的研究。而神經幹細胞則是具有多向分化潛能的功能性細胞，具有修補中樞神經的潛力。體外培養所使用的細胞培養基材，一直是影響細胞培養的一大因素，因此本研究中探討生物活性分子(聚離氨酸)、 矽晶片、氮化鎵、砷化鎵及一般常使用的細胞培養盤在培養神經細胞或神經幹細胞時所造成細胞貼附及生長的差異性。另外為了了解造成這些差異性的原因，本研究選用嗜鉻性神經細胞瘤細胞株，嘗試從訊息傳導路徑有關的蛋白質做相關的分析，藉由蛋白質表現量的不同來解釋細胞行為的差異。一章介紹中樞神經細胞、神經幹細胞、嗜鉻性神經細胞以及所使用之半導體材料對於培養細胞之應用與比較。二章在探討神經細胞分別在氮化鎵、矽基材以及一般培養皿培養三到六天後細胞之貼附與分化的程度，根據光學照片結果顯示，在培養三天後之神經細胞大多能在各個基材上形成細胞貼附與分化。而在培養到六天時，在氮化鎵基材的作用下，神經細胞會呈現更高度的分化，矽基材上在貼附及分化上皆呈現下滑的趨勢，另外在乳酸脫氫脢量測細胞貼附數量的檢測，也呈現相同的趨勢。三章則是探討氮化鎵培養神經細胞在長時間下的神經突觸功能表現，結果顯示氮化鎵相對於聚離氨酸與一般培養皿具有較佳保持神經突觸功能的情形，而在相對細胞死亡測試實驗中，也顯示氮化鎵較能促進細胞的存活，此結果可能由於氮化鎵基材在早期磷酸化了蛋白質Akt。四章主要探討神經幹細胞在氮化鎵和聚離氨酸上的分化情形，培養結果顯示在這兩種基材上皆能讓細胞貼附及分化，相對於聚離氨酸，氮化鎵更能讓神經幹細胞往神經細胞的路徑去分化，此結果可能導因於glycogen synthase kinase-3β (GSK-3β)活性的抑制，而進入神經細胞的分化。另一方面，氮化鎵具有讓神經幹細胞長時間貼附與促進細胞存活的能力。五章則是以嗜鉻細胞做為研究神經細胞訊息傳導路徑模型，實驗結果顯示氮化鎵可能會經由Akt/GSK-3β/ caspase-3路徑，阻止神經細胞的凋亡，進而促進神經細胞的存活，在乳酸脫氫酶測試上也呈現相同的趨勢。六章總結本研究的貢獻，本研究重要的發現在於三五族半導體氮化鎵單晶所造成的Lewis acid-base性質能夠促進神經細胞以及神經幹細胞的貼附及分化，使得它在神經生物晶片與細胞體外培養系統發展上更具競爭力。Neurons can only grow well in body by means of neurotrophic factors and afferent neuron stimulus. Cerebellar granule neurons belong to highly uniform neural culture model, and have been widely used in neuron growth and apoptosis mechanism researches. Neural stem cells are functional cells with multi-differentiation potency, having potential of repairing central nerve. Cell culture substrate for in vitro cultivation has always been a major factor in cell culture. This study examined cell adhesion and differentiation difference when adopting bioactive molecule-polylysine, silicon chip, GaN, GaAs and commonly used cell culture dish (polystyrene) as substrate of cultivating neurons or neural stem cells respectively. In addition, to understand the cause of such differences, this study selected neuronal pheochromocytoma strain was selected in to analyze signal transduction pathway, and cell behavior variation can be attributed to protein expression difference. hapter 1 introduces application and comparison of central neuron, neural stem cell, chromaffin neuron and semiconductor material used on cell culture. hapter 2 discusses neuron adhesion and differentiation after cultured on GaN, silicon substrate and tissue culture polystyrene (TCPS) for 3-6 days. As shown by optical micrographs, after cultured for three days, most neurons could form cell adhesion and differentiation on every above substrate. And after cultured for six days, neurons on GaN substrate showed more differentiation, neurons on silicon substrate reported deteriorated adhesion and differentiation. Furthermore, cell adhesion degree inspection on lactate dehydrogenase showed the same trend. hapter 3 describes the long-term synapsis performance of GaN cultured neuron, showing that, GaN has better retention of synapsis function, as compared to polylysine and TCPS. Relative cell death test also showed that GaN could better promote cell survival, probably due to phosphorylation of Akt on GaN substrate in earlier time. hapter 4 examines neural stem cell differentiation on GaN and polylysine respectively. Cultivation showed that both substrates could enable cell adhesion and differentiation, GaN was more likely than polylysine to enable neural stem cell differentiation along neuron path, probably due to inhibited activity of glycogen synthase kinase-3β (GSK-3β). On the other hand, GaN is capable of promoting long term adhesion of neural stem cell and cell survival. hapter 5 takes chromaffin cell as the model of research on neuron signal transduction pathway. The experiment found that, GaN may suppress neuron apoptosis via Akt/GSK-3β/caspase-3 path, and thus promote neuron survival; lactate dehydrogenase test indicated the same trend.hapter 6 concludes the contribution of this study that Lewis acid-base property derived from Group III/V semiconductor GaN single crystal could promote adhesion and differentiation of neurons and neural stem cells.摘要.......................VBSTRACT.......................VIIHAPTER 1 INTRODUCTION....................... 1-1. Application of materials.......................1-2. Central Nerve Cell.......................2-3. Functions of Granule Cell .......................3-4. Neural stem cell.......................3-5. Application of NSC .......................4-6. Pheochromocytoma cell .......................5-7. References .......................7hapter 2 Assessment of GaN chips for culturing cerebellar granule neurons.......................10-1. Introduction.......................10-2. Materials and Methods.......................11-2-1. Sample preparation and characterization...........11-2-2. Cell culture.......................12-2-3. Cell morphology.......................12-2-4. Assessment of neuronal survival....................12-2-5. Western blot analysis.......................13-3. Results.......................14-3-1. Roughness of GaN and Si.......................14-3-2. Cell morphology.......................14-3-3. LDH assay.......................15-3-4. GAP43 western plot.......................16-4. Discussion .......................17-5. Conclusion.......................20-6. References.......................21hapter 3 The effect of gallium nitride on long-term culture induced aging of neuritic function in cerebellar granule cells.............31-1. Introduction.......................31-2. Materials and methods.......................34-2-1. Sample preparation.......................34-2-2. Cell culture .......................34-2-3. Cell morphology.......................34-2-4. Immunofluorescence microscopy.........................35-2-5. Western blot analysis.........................36-2-6. LDH assay..........................36-3. Results.......................38-3-1. The effect on phosphorylation of Akt ..............38-3-2. The effect on neurite fasciculation................38-3-3. The effect on axonal growth and synaptogenesis ...........................40-3-4. LDH assay........................41-4. Discussion.........................43-5. Conclusion ........................46-6. References.........................47hapter 4 Gallium Nitride induces neuronal differentiation markers in neuraltem/precursor cells derived from rat cerebral cortex.........................61-1. Introduction ..........................61-2. Materials and methods.......................63-2-1. Sample preparation.............................. 63-2-2. Isolation and culture of NSPCs....................63-2-3. Immunocytochemistry.......................64-2-4. Western blot analysis .......................65-2-5. LDH assay.......................65-3. Results .......................67-3-1. Effect of GaN on NSPC adhesion.......................67-3-2. Effect of GaN on NSPC differentiation.......................67-3-3. The effect of GaN on the long-term cultured NSPCs.......................69-4. Discussion.......................70-6. References.......................75hapter 5 GaN films maintaining PC12 cells survival viaAkt/GSK-3β/caspase-3ediated signaling pathway.......................86-1. Introduction.......................86-2. Materials and Methods.......................89-2-1. Sample preparation .......................89-2-2. Cell culture .......................89-2-3. Cell morphology.......................89-2-4. LDH assay.......................90-2-6. Measurement of caspase-3 activity..................91-2-7. Statistical analysis.......................91-3. Results.......................93-3-1 Cell morphology.......................93-3-2. LDH assay.......................93-3-3. ERK phosphorylation.......................94-3-4. Akt phosphorylation .......................95-3-5. The effect of GaN on PC12 cells in the absence of NGF.......................95-3-6. Caspase-3 assay.......................97-4. Discussion.......................99-5. Conclusion.......................105-6. References.......................106HAPTER 6 Summary.......................11
Gallium Nitride Induces Neuronal Differentiation Markers in Neural Stem/ Precursor Cells Derived from Rat Cerebral Cortex
No full textIn the present study, gallium nitride (GaN) was used as a substrate to culture neural stem/precursor cells (NSPCs), isolated from embryonic rat cerebral cortex, to examine the effect of GaN on the behavior of NSPCs in the presence of basic fibroblast growth factor (bFGF) in serum-free medium . Morphological studies showed that neurospheres maintained their initial shape and formed many long and thick processes with the fasciculate feature on GaN. Immunocytochemical characterization showed that GaN could induce the differentiation of NSPCs into neurons and astrocytes. Compared to poly-D-lysine (PDL), the most common substrate used for culturing neurons, there was considerable expression of synapsin I for differentiated neurons on GaN, suggesting GaN could induce the differentiation of NSPCs towards the mature differentiated neurons. Western blot analysis showed that the suppression of glycogen synthase kinase-3 beta (GSK-3 beta) activity was one of the effects of GaN-promoted NSPC differentiation into neurons. Finally, compared to PDL, GaN could significantly improve cell survival to reduce cell death after long-term culture. These results suggest that GaN potentially has a combination of electric characteristics suitable for developing neuron and/ or NSPC chip systems
sj-jpg-1-cll-10.1177_09636897231190178 – Supplemental material for Early and Dose-Dependent Xenogeneic Mesenchymal Stem Cell Therapy Improved Outcomes in Acute Respiratory Distress Syndrome Rodent Through Ameliorating Inflammation, Oxidative Stress, and Immune Reaction
No full textSupplemental material, sj-jpg-1-cll-10.1177_09636897231190178 for Early and Dose-Dependent Xenogeneic Mesenchymal Stem Cell Therapy Improved Outcomes in Acute Respiratory Distress Syndrome Rodent Through Ameliorating Inflammation, Oxidative Stress, and Immune Reaction by Kun-Chen Lin, Wen-Feng Fang, Pei-Hsun Sung, Kuo-Tung Huang, John Y. Chiang, Yi-Ling Chen, Chi-Ruei Huang, Yi-Chen Li, Mel S. Lee and Hon-Kan Yip in Cell Transplantation</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
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Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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