In situ observation of the dissolution kinetics of Al_(2)O_(3) particles in CaO–Al_(2)O_(3)–SiO_(2) slags using laser confocal scanning microscopy

The dissolution kinetics of Al_(2)O_(3) in CaO-Al_(2)O_(3) SiOslags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 K.The results show that the controlling step during the Al_(2)O_(3) dissolution was the diffusionin molten slag.It was found that the dissolution curves of Al_(2)O_(3) particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al_(2)O_(3) ratio of slag.A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al_(2)O_(3) in slag.Diffusion coefficients of Al_(2)O_(3) in slag were calculated as 2.8×10to 4.1×10m~2/s at the temperature of 1773-1873 K.The dissolution rate of Al_(2)O_(3) increased with higher temperature,CaO/Al_(2)O_(3),and particle size.A new model was shown to be v_(Al_(2)O_(3))=0.16×r_(0)^(1.58)×x^(3.52)×(T-T_(mp))^(1.11)to predict the dissolution rate and the total dissolution time of Al_(2)O_(3) inclusions with various sizes,where vAl_(2)O_(3) is the dissolution rate of Al_(2)O_(3) in volume,μm^(3)/s;x is the value of CaO/Al_(2)O_(3) mass ratio;R_(0) is the initial radius of Al_(2)O_(3),μm;T is the temperature,K;T_(mp) is the melting point of slag,K.

Confocal Laser Scanning Microscope Evaluation of Early Bacterial Colonization on Zirconium Oxide and Titanium Surfaces:An in vivo Study

To investigate the bacterial colonization on zirconium oxide and titanium surfaces in vivo quantitatively using a confocal laser scanning microscope (CLSM). Ten samples of zirconium oxide ceramic and commercially pure titanium were fabricated and polished using silicon carbide abrasive paper. One sample from each group was evaluated topographic pattern under a scanning electron microscope. One sample from each group was to evaluate roughness using a profilometer. Eight volunteers were selected. The samples were cemented at the buccal surfaces of upper first molars. All samples were removed after 48 hours, immersed in SYTO-9 and propidium iodide fluorescent to stain for adherent bacteria and observed with CLSM. Fewer bacteria were observed in zirconia group than titanium group. However, there was no statistical difference between two groups. The experimental results demonstrate that zirconium oxide may be considered as a promising material for dental implant abutments.

Qualitative analysis of re mineralized carious lesions subjected to fluoride supplement through confocal laser scanning microscope

Aim: 1] Comparative evaluation of the linear depth of induced remineralized lesions after subjecting to fluoride supplements and 2] To assess the average fluorescence at both the demineralized and the remi-neralized zones in all the three study groups under confocal laser scanning microscope. Method: Forty five sound human premolars extracted for orthodon-tic reasons were decoronated 1 mm below the ce-mento-enamel junction and coated with nail varnish except for a 3 × 3 mm window on the buccal surface. The samples were placed in 50 ml of de mineralizing solution at pH 4.6 for 96 hours. Following deminera-lization, the lower half of the 3 × 3 mm window in all the samples were covered with nail varnish to serve as control. The samples were randomly divided into three groups of fifteen teeth each (n = 15) and speci-mens in group A[Nfd] were remineralized using non-fluoridated dentifrice [control], those in groups B [Fd5] and group C [Fd10] using 500 ppm and 1000 ppm of fluoride containing dentifrice, respectively. The specimens were subjected to a 20 day reminera-lization treatment regimen and were sectioned into 100 μm thick sections and two images were captured on the buccal surface from either side of the midpoint of occluso-cervical length using confocal laser scan-ning microscope [CLSM]. Results: were tabulated and statistically analyzed by Anova. Study concluded that 1000 ppm fluoridated dentifrice showed a greater degree of remineralization than other groups and confocal laser scanning microscopes gives promising results in the diagnosis of early enamel lesions over the conventional methods.

Quantum Dots as Fluorescent Labels for Detection of Heat Shock Protein in Tumor Tissue Using Laser Scanning Confocal Microscope

A new Quantum Dots(Qdots) nanocrystal composed of semiconductor core and zinc sulfide shell, and its feasibility as labels in immunofluorescence analysis for the imaging of tumor biomarkers by laser scanning confocal microscope(LSCM) was investigated. Qdots taged by mercaptoacetic acid were conjugated with second antibody, then imaging differences of Heat Shock Proteins 70(HSP70) in renal carcinoma tissure sections with immunofluorescence analysis method using Qdots bioconjugates and conventional organic dye FITC were observed by LSCM to assess the brightness and opticalstability of Qdots. The experimental results showed Qdots bioconjugates achieved the better results in demonstrating HSP70 with more brighter color and more clear picture than FITC labels. Moreover, the label signals of Qdots did not fade clearly after continued exposure to a 488 nm laser for 1 h. The Qdots bioconjugates have good feasibility in immunofluorescence analysis for the bioimaging by LSCM.

Using laser confocal scanning microscope to study ischemia-hypoxia injury in rat brain slice

The level of lipid peroxidation and cellular necrosis in rat living brain slices during brain ischemia-hypoxia injury have been observed using a laser confocal scanning microscope (LCSM) with double labeling of fluorescent probes D-399 (2, 7-dichlorofluorescin diacetate) and propidium iodide (Pl). The hypoxia and/or reoxygenation injury in rat brain slices is markedly decreased by pretreatment with L-NG-nitro-arginine (L-NNA) and N-acetylcysteine (NAC), showing that the nitric oxide (NO) and other free radicals play an important role in brain ischemia-hypoxia injury.

Dispersion of particles in the coatings characterized by laser scanning confocal micrscopy(LSCM) I:Vertical dispersion of particles in the coatings and the weathering property studied by orthogonal analysis method of LSCM

Two kinds of TiO_2 filled epoxy coatings were designed and prepared to obtain pigments with different dispersion degrees of TiO_2 particles.Laser scanning confocal microscope(LSCM)was used to investigate both the horizontal and vertical distributions of TiO_2 particles in the coatings.The results indicated that TiO_2 in the two samples shared considerable similarity in horizental dispersion,but exhibited great difference in vertical dispersion.TiO_2 showed uniform vertical distribution in disp coating,wheras a gap about 1.1μm was found in the non-disp coating,which significantly influenced the surface optical properties of the coatings during weathering.Based on the confocal data,the model of dispersion of pigments in the coatings was proposed and the change of surface properties during weathering was predicted:the surface optical properties showed an initial decrease followed by a subsequent increase,which was in good agreement with the weathering data.

激光共聚焦显微镜应用于本科生的实验教学设计

激光共聚焦显微镜等大型仪器的实验教学是实现“新工科”建设的重要推动力,然而目前针对本科生的大型仪器教学却未得到有效普及。通过选取适合于本科生实践操作的微生物荧光染色观察实验以及基于“雨课堂”进行线上线下教学,发挥激光共聚焦显微镜可视化强的特点,激发本科生的求知欲望和探索热情,增强学生的主观能动性,促进以教师为主导向以学生为中心的教学模式转变。实践教学表明,易于操作、可视化强的实验方案有助于学生理解和掌握激光共聚焦显微镜相关的基础知识和未来应用,拓宽学生的知识面和科研视野,提高本科生的实践创新能力。

尼康共聚焦显微镜使用的大数据分析

激光共聚焦显微镜是目前最精密的光学成像仪器,是生命领域重要的研究工具。兰州大学生命科学研究实验中心的尼康共聚焦显微镜两年多时间工作了1万多小时,获取了大量的观测数据。对使用记录的分析表明,仪器在每天上午9点到晚上22点处于饱和工作状态,只有在寒假期间有所降低,说明了全天候开放使用的必要性。观测结果分析得到了很多有价值的信息,例如,488 nm和561 nm激光器使用率都超过了三分之一,单激光和双激光观测占比分别是72%和24%,高灵敏检测通道使用率接近90%等。综合这些信息,可以为共聚焦显微镜的管理和培训提供科学的依据。

激光扫描共聚焦显微镜LSM900 with Airyscan2的管理模式探索

激光扫描共聚焦显微镜是生物、医药、化学等科学领域成像研究的一个重要工具,也是目前大型仪器平台不可或缺的成像设备。LSM900 with Airyscan2是目前市面上较新的一款多功能、快速、高分辨率的激光扫描共聚焦显微镜。对激光扫描共聚焦显微镜的原理、其运行的环境要求、管理人员职责、开放共享管理以及设备维护保养注意事项几方面做详细地介绍,供相关管理人员与使用者参考。

融合免疫荧光技术的共聚焦显微镜实验教学实践

为了建立完整的科研实验技能学习体系,构建了高效可行的实验教学课程,并对近年开展的激光扫描共聚焦显微镜技术实验教学课程内容和方法进行了优化和实践。课程将科学理论与实验技能有机结合,把间接免疫荧光技术融合到共聚焦显微镜实验教学中,克服大型成像仪器教学中时间和空间限制。该教学课程帮助学生掌握共聚焦显微镜技术原理、应用和实验方法,提高学生们的实验动手能力和科研素养。

高内涵分析系统联合激光扫描共聚焦显微镜观察细胞间隧道纳米管

目的隧道纳米管(tunneling nanotubes,TNTs)是存在于细胞间的膜管样结构,具有直接且远距离的生物信息交换功能。TNTs因结构易破坏、存在时间短以及形成后不稳定,故观察其动态形成与功能存在一定难度。而本研究采用高内涵分析系统(HCA)联合激光扫描共聚焦显微镜(LSCM)尝试观察TNTs形成的动态过程及其对囊泡物质的转运功能。方法荧光探针标记人肺腺癌A549及顺铂耐药A549/DDP细胞,分别利用HCA观察TNTs形成过程、LSCM观察TNTs三维结构、HCA联合LSCM分析TNTs囊泡物质转运功能。结果同种肿瘤细胞(A549或A549/DDP)间、不同亚型肿瘤细胞(A549与A549/DDP)间均可形成TNTs结构;与A549细胞相比,A549/DDP细胞间TNTs结构长且粗、形成指数高(A549和A549/DDP细胞TNTs长度、直径和形成指数分别为14.71μm、2.27μm、4和25.44μm、2.59μm、11);肿瘤细胞间通过细胞接触-膜融合-细胞反向易位-胞膜融合区拉长变细,以及细胞膜凸起-膜凸起丝状伪足样拉长-膜凸起与其他细胞膜/膜凸起融合两种方式形成TNTs;TNTs囊泡转运功能具有双向性,囊泡转运速率及数量因转运阶段和供体细胞不同而存在差异,A549/DDP细胞向A549细胞进行囊泡转运过程中表现为囊泡转运速率初始快、末期慢,A549作为供体细胞向受体A549/DDP细胞转运的囊泡数量和比例高于A549/DDP作为供体细胞的反向转运。结论HCA联合LSCM可有效观察、分析TNTs动态形成过程及囊泡物质转运功能。

超高分辨率激光扫描共聚焦显微镜的成像技术与应用

超高分辨率激光扫描共聚焦显微镜在生命科学研究领域中的应用日益广泛。该文以Zeiss LSM 880 Airyscan with STEDYCON超分辨率激光共聚焦显微镜为例,介绍了Airyscan技术和基于受激发射现象的超分辨技术(STED)的原理、应用和参数设置,以期能够为科研工作者究竟采用哪种模式进行图像采集提供参考,以获得最佳的成像效果。

基于激光扫描共聚焦显微镜的蛋白质相分离研究方法

激光扫描共聚焦显微镜(LSCM)具有高分辨率、高对比度和可定量测量等优势,其在细胞及组织成像等方面的广泛应用极大地推动了生命科学领域的发展。相分离的研究极度依赖显微成像技术,本文着重总结了基于激光扫描共聚焦显微镜的相分离研究方法,并探讨了相分离研究的难点,为相关研究人员了解蛋白质相分离及显微镜在相分离领域的应用提供了参考,也为开展相分离研究提供了技术依据。

圆锥角膜不同交联方法术后基质分界线发生特点及其对交联效果的影响

目的比较早期圆锥角膜接受核黄素/紫外线A角膜胶原交联术(CXL)不同手术方式术后基质分界线的特点,并分析基质分界线对交联效果的影响。方法采用非随机对照临床研究方法,选取2019年5月至2021年2月于山东第一医科大学附属眼科医院就诊的圆锥角膜患者69例69眼,所有患者均行CXL治疗,其中经上皮交联组21眼,去上皮交联组48眼;5.4 J能量组25眼,7.2 J能量组44眼。分别于术后2周、1个月、3个月、4个月进行随访,观察角膜基质交联反应(基质分界线)的形态及变化特点;记录角膜最薄处厚度(TCT)、裸眼视力(UCVA,LogMAR)、最佳矫正视力(BCVA,LogMAR)和角膜最大曲率(Kmax)等的变化。结果术后出现基质分界线占63.77%(44/69),未出现基质分界线占36.23%(25/69)。去上皮交联组出现基质分界线占79.17%(38/48),明显高于经上皮交联组的28.57%(6/21),差异有统计学意义(χ^(2)=16.186,P<0.01);5.4 J能量组出现基质分界线占72.00%(18/25),7.2 J能量组占56.80%(25/44),差异无统计学意义(χ^(2)=1.565,P=0.302)。裂隙灯显微镜及眼前节光学相干断层扫描显示基质分界线于术后1~2周时出现,1个月时逐渐汇聚、增强;2~3个月后基质分界线开始变得弥散、边界模糊,并逐渐变淡;4个月时基质分界线基本消失。基质分界线深度可达141~423μm,平均(263.44±84.22)μm。激光扫描共聚焦显微镜观察结果显示,交联术后角膜基质细胞激活,反光增强,胶原纤维纵横伸展并相互交错,纤维排列呈网状。术后4个月,TCT由术前的(458.69±38.28)μm降至(443.86±36.54)μm,差异有统计学意义(t=6.705,P<0.001);有基质分界线组与无基质分界线组术后TCT下降幅度比较,差异无统计学意义(t=1.684,P=0.100)。术后4个月所有术眼UCVA由术前的0.74±0.37提高至0.69±0.38,差异有统计学意义(t=2.109,P=0.039);手术前后BCVA比较,差异无统计学意义(t=1.006,P=0.319)。有基质分界线组与无基质分界线组术后UCVA和BCVA变化量比较,差异均无统计学意义(t=0.065,P=0.949;t=0.346,P=0.730)。手术前后所有患者Kmax比较,差异无统计学意义(t=0.050,P=0.950);有基质分界线组和无基质分界线组术后Kmax变化量比较,差异无统计学意义(t=-0.739,P=0.464)。去上皮交联组术后TCT变化量明显大于经上皮交联组,差异有统计学意义(t=2.815,P=0.008),2个组间术眼术后UCVA、BCVA和Kmax变化量比较,差异均无统计学意义(均P>0.05)。所有患者术后无明显角膜瘢痕、感染性角膜炎、角膜内皮失代偿等并发症。结论圆锥角膜CXL术后出现基质分界线可能是交联反应深度的标志;去上皮手术方式术后更容易出现基质分界线;2种角膜胶原交联模式有相似的治疗效果;圆锥角膜不同交联方法术后基质分界线的发生与否对交联效果无明显影响。

Highly specific characterization and discrimination of monosodium urate crystals in gouty arthritis based on aggregation-induced emission luminogens

Existing technologies used to detect monosodium urate(MSU)crystals for gout diagnosis are not ideal due to their low sensitivity and complexity of operation.The purpose of this study was to explore whether aggregation-induced emission luminogens(AIEgens)can be used for highly specific imaging of MSU crystals to assist in the diagnosis of gout.First,we developed a series of luminogens(i.e.,tetraphenyl ethylene(TPE)-NH_(2),TPE-2NH_(2),TPE-4NH_(2),TPE-COOH,TPE-2COOH,TPE-4COOH,and TPE-Ketoalkyne),each of which was then evenly mixed with MSU crystals.Next,optimal fluorescence imaging of each of the luminogens was characterized by a confocal laser scanning microscope(CLSM).This approach was used for imaging standard samples of MSU,hydroxyapatite(HAP)crystals,and mixed samples with 1:1 mass ratio of MSU/HAP.We also imaged samples from mouse models of acute gouty arthritis,HAP deposition disease,and comorbidities of interest.Subsequently,CLSM imaging results were compared with those of compensated polarized light microscopy,and we assessed the biosafety of TPE-Ketoalkyne in the RAW264.7 cell line.Finally,CLSM time series and three-dimensional imaging were performed on MSU crystal samples from human gouty synovial fluid and tophi.As a promising candidate for MSU crystal labeling,TPE-Ketoalkyne was found to detect MSU crystals accurately and rapidly in standard samples,animal samples,and human samples,and could precisely distinguish gout from HAP deposition disease.This work demonstrates that TPE-Ketoalkyne is suitable for highly specific and timely imaging of MSU crystals in gouty arthritis and may facilitate future research on MSU crystal-related diseases.

激光共聚焦扫描显微镜载样台改造及使用

激光共聚焦扫描显微镜已经成为了生物科学研究中不可或缺的大型高端光学成像仪器。但由于生物样品来源和类型丰富,而购置的激光共聚焦显微镜单一形式载样台不能满足各类生物学样品的使用。本工作在Leica TCS SP8激光共聚焦显微镜载样台的基础上,设计了一种能够避免原装载样台造成物镜撞击载物台并且能够更好的适应生物科研中各类成像样本的新载样台。改造结果显示更换载样台后,极大的降低了载物台撞显微镜物镜的概率,避免了显微镜物镜的损伤和因载样台的限制而不能进行成像造成样本的浪费,并且更加方便显微镜的日常使用。该次载样台改造的尝试为国内其他科研平台或仪器制造商提供了设计一种更好适应不同样品和物镜友好样品台的思路,具有很大的实用价值和借鉴意义。

激光扫描共聚焦显微镜研究储层孔隙结构

这是一项首次应用激光扫描共聚焦显微镜 (LSCM)的激光荧光技术于油气储层的孔隙结构研究。供LSCM用的样品 ,用环氧树脂加入荧光剂后 ,经加压灌注 ,磨制成岩石薄片 ,在LSCM显微镜下观察孔喉的分布 ,可以测量面孔率 ,并可标出需要测量的每个孔喉的大小以及观察孔喉形状及分布状况。该法的优点 :1.可直接测量和观察到 2 μm左右大小的孔喉。 2 .在LSCM显微镜下可区分孔隙空间中的充填粘土杂基等 ,因此面孔率的测定较一般镜下统计和图像分析更为精确 ,因粘土矿物由于吸附染色剂后在颜色或灰度上有的不易区分。 3.岩石薄片中的微裂缝 ,在LSCM显微镜下可以更清楚地观察到。

葛根素对外周血内皮祖细胞数量和功能的影响

目的 :观察葛根素对外周血内皮祖细胞的影响。方法 :采用密度梯度离心法从外周血获取单个核细胞 ,将其接种在人纤维连接蛋白包被培养板 ,培养 7d后 ,收集贴壁细胞 ,加入不同浓度葛根素 (分别为 0 .1,0 .5 ,1,3mmol·L-1)培养一定的时间 (6 ,12 ,2 4 ,4 8h)。通过激光共聚焦显微镜鉴定FITC UEA Ⅰ和DiI acLDL双染色阳性细胞被认为是正在分化的EPC ,并在倒置荧光显微镜下计数。然后分别采用MTT比色法、改良的Boyden小室、黏附能力测定实验和体外血管生成试剂盒观察EPC的增殖能力、迁移能力、黏附能力和体外血管生成能力。结果 :葛根素显著增加外周血EPC数量 ,并且EPC数量随葛根素浓度增加及作用时间延长而增加 ,3mmol·L-1浓度葛根素作用 2 4h对EPC数量的影响最为显著 (较对照组增加了 1倍 ,P <0 .0 1)。葛根素也显著改善了外周血EPC的黏附能力、迁移能力、增殖能力和体外血管生成能力。结论

银杏叶提取物对外周血内皮祖细胞数量和功能的影响

目的 观察银杏叶提取物对外周血内皮祖细胞 (endothelialprogenitorcell,EPC)数量和功能的影响。方法 密度梯度离心法获取外周血单个核细胞 ,培养 7d后 ,收集贴壁细胞并加入银杏叶提取物 (10 ,2 5和 5 0mg·L- 1 )干预一定时间 (6 ,12 ,2 4和 4 8h)。激光共聚焦显微镜和流式细胞仪鉴定EPC ,分别观察EPC的增殖、迁移、粘附和体外血管生成能力。结果 银杏叶提取物促进外周血EPC扩增 ,2 5mg·L- 1 银杏叶提取物作用 2 4h对EPC数量的影响最为显著 (较对照组增加了 1倍 ,P <0 .0 1)。银杏叶提取物也显著改善了外周血EPC的粘附、迁移、增殖和体外血管生成能力。

利用激光扫描共聚焦显微镜观察同源四倍体水稻胚囊的形成与发育

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