Y_(2)O_(3):Yb^(3+),Er^(3+)上转化荧光纳米粒子在潜指纹显现中的应用

文章通过高温煅烧方法制备出Y_(2)O_(3):Yb^(3+),Er^(3+)纳米粒子,通过XRD、TEM和元素面扫描对其特性进行研究。通过该方法成功制备出Y_(2)O_(3):Yb^(3+),Er^(3+)纳米粒子,该纳米粒子具有较好的分散性,尺寸约为100 nm。在980 nm近红外光的激发下,产生绿色和红色两个发光带。Y_(2)O_(3):Yb^(3+),Er^(3+)在980 nm近红外光的激发下,可以有效地显现红色纸盒和绿色塑料卡片等带有颜色干扰的非渗透性客体表面的潜指纹,由于激发波长为近红外光,可以完全避免背景荧光的干扰,最大程度上显现指纹的一级和二级结构特征。此外,在与商品红色荧光粉末的比较研究中发现,在有荧光特性的渗透性客体表面的潜指纹显现中,Y_(2)O_(3):Yb^(3+),Er^(3+)纳米粒子具有优势,呈现出更加清晰的指纹轮廓和纹线,可以有效消除背景花纹的干扰,具有较高的灵敏度和选择性。

Li^+增强Ho^(3+)/Yb^(3+):Y_2O_3纳米晶的上转化发光研究

采用凝胶溶胶法制备了不同浓度的Y2O3:Ho3+/Yb3+/Li+纳米晶,并且系统研究了不同掺杂浓度对上转化荧光现象的影响。首先,通过XRD图形判断了晶体结构的生成,再通过980 nm的激光器和荧光光谱仪测得的光谱图,发现了位于520~579 nm的绿光、635~674 nm的红光等两条很强的可见光,还有一条较弱的位于743~775 nm的近红外发光。最后,通过与能级图比较和分析可以得出:它们分别是5F4/5S2→5I8,5F5→5I8和5F4/5S2→5I7荧光跃迁。可以看出:在掺杂入Li+之后,上转化荧光得到了极大增强。

基于上转化发光免疫层析技术建立发热伴血小板减少综合征病毒总抗体快速检测方法

目的基于上转化发光(UPT)免疫层析技术,建立发热伴血小板减少综合征病毒(SFTSV)总抗体的现场快速检测方法。方法将SFTSV重组NP蛋白与上转化发光颗粒(UCP)偶联,制备UCP-NP免疫层析试纸条,评价该试纸条检测SFTSV总抗体的灵敏性、特异性和稳定性,并检测SFTSV血清254份,与酶联免疫法(ELISA)比较。结果该方法可在15min内完成SFTSV总抗体检测,可检测1∶500稀释度的SFTSV阳性血清,与其他出血热病毒无交叉反应,加样14d内稳定性较高。UPT免疫层析法与ELISA法检测临床血清样品一致性极高(Kappa=0.967),约登指数为0.973。结论建立了基于UPT免疫层析技术的SFTSV总抗体快速检测方法,该方法灵敏、特异,且操作简便、快速,结果稳定,适合在基层门诊和体检现场推广。

溶胶-凝胶法制备稀土Er^(3+)-Yb^(3+)掺杂CaTiO_3上转化绿红光材料的研究(英文)

通过溶胶-凝胶法制备稀土Er3+-Yb3+掺杂CaTiO3上转化绿红光材料,以透射电子显微镜(TEM)与X射线衍射仪(XRD)为手段证明了材料的纳米结构.研究结果显示,上转化发光材料的绿光与红光,主要在520~550nm与660~680 nm且绿光是红光强度的2~3倍,当Yb3+的浓度达到3%(mol/mol)绿光是红光强的强度达到峰值.研究发现,Er3+-Yb3+掺杂CaTiO3材料,绿光与红光上转化发光过程涉及双光子,此材料是一种发光性能优异的材料.

基于纯有机电致发光器件实现红外至可见光信号上转化

在有机红外光敏剂掺杂的有机电致发光器件(OLED)中实现近红外光信号到可见光的上转化,为大面积柔性有机红外上转化器件提供一种原型设计。

紫外可见上转换剂/TiO_2复合光催化剂在海洋石油污染处理中的应用

在实验室条件下,取大连市黑石礁海域海水,加入风化好后的柴油配制成模拟石油污染海水,通过分别改变催化剂的掺杂比、溶液pH、催化剂添加量、光照时间和柴油初始浓度等因素,研究各因素对上转换材料TiO2复合光催化剂催化降解海洋石油污染的影响效果,并通过正交试验优化了光催化降解海洋石油污染的条件。结果表明:在海洋中柴油初始浓度为0.1 g/L时,催化剂掺杂比为15%,催化剂添加量为40mg,溶液pH为7的条件下催化降解2.5 h,海洋石油污染光催化降解效果最好,降解率可达88.85%。

Er3+掺杂0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3压电陶瓷的性能研究

采用传统固相烧结方法制备了Er^3+掺杂0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3无铅压电陶瓷.考察了不同浓度Er^3+离子掺杂对其晶体结构和上转化发光性能的影响.XRD实验结果表明制备出的陶瓷样品均为纯的钙钛矿结构,且形成三方相和四方相的准同型相界.在980nm波长激发下,陶瓷显现出明显的上转化发光性能,有3个明显的Er^3+特征峰,分别位于528,550nm处绿光发射和661nm处红光发射;当Er^3+掺杂量x=0.015mol时,上转换发光性能达到最佳.该材料属于一种光-电多功能材料,即既具有上转换发光性能又具有铁电/压电性能.稀土掺杂0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3固溶体的发光性能可以通过电场来调控.

亲水性Yb^(3+)/Er^(3+)/Gd^(3+)共掺杂NaYF_4上转换纳米材料的制备和发光性能的研究

在较低的温度下和超短的时间内,一步合成了以NaYF_4为基质掺杂Yb^(3+),Er^(3+)和Gd^(3+)的亲水性上转换纳米颗粒,并通过TEM和XRD对其进行了形貌表征和物相分析.最后对其发光性能进行了研究,发现该纳米颗粒在980nm激光的照射下,可发射出明亮的绿光.

上转换荧光探针的制备及其植物细胞成像

采用简易的热熔剂法,成功地制备了Yb3+和Er3+共掺杂的Na Lu F4纳米晶。由于其很强的上转化发光及经过表面修饰后很好的生物相容性,Na Lu F4纳米晶被应用作为上转化荧光探针,对西红柿表皮细胞进行荧光成像,结果表明,上转化纳米探针能很好地吸附在西红柿细胞的细胞壁,对细胞的形貌进行清晰的成像,为动植物细胞的研究提供了新的成像途径。

紫外可见上转换剂/TiO_2复合光催化剂在海洋石油污染处理中的应用

本文就紫外可见上转换剂/TiO_2复合光催化剂在海洋石油污染处理中的应用进行了研究。首先进行模拟石油污染海水的制备,对各种变量因素进行改变,包括改变石油初始浓度、溶液PH、催化剂用量以及催化剂掺杂比等,研究各种因素对上转换材料TiO_2复合光催化剂催化降解海洋石油污染的影响效果,同时开展正交试验得到光催化降解海洋石油污染的最佳条件。

溶胶-凝胶法制备Y_2O_3∶Er^(3+)上转换材料及降解氧乐果的研究

采用可见光适用性的光催化产品降解农药残留不但适用于农民的田间使用,也可以供城市居民居家使用。该文用溶胶凝胶法制备了Y_2O_3∶Er^(3+)上转换材料,并与锐钛矿型氧化钛溶胶混合,开展在可见光下降解氧乐果的研究。通过选取蔬菜表面氧乐果浓度、可见光降解剂量、p H值、降解时间等因素进行了正交实验设计以确定最佳降解条件,结果显示:降解率与蔬菜表面氧乐果浓度大小关联度最大,而降解时间次之。

Optimization of Parameters of Exogenous Gene Mediated by Liposome to Transfect Yak Mammary Epithelial Cells in Vitro

[Objective] The aim of this study was to optimize conditions of exogenous gene mediated by liposome to transfect yak mammary epithelial cells in Vitro.[Method] Yak mammary epithelial cells were isolated and cultivated in Vitro by the methods of collagenase digestion and tissue adhesion.The expression of cytokeratin in yak mammary epithelial cell was detected by immunocytochemistry technique.With green fluorescence protein as the report gene,yak mammary epithelial cells were transfected with exogenous gene m...

Epithelial-mesenchymal transition and cancermetastasis

Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Recent researches indicated that EMT plays a critical role in various tumors progression, through which epithelial cancers invade and metastasize. The cell characteristics are changed during EMT, in which the cells lose cell-cell and cell-matrix interactions and apical polarity, reorganize their cytoskeleton, and become isolated, motile, as well as resistant to anoikis, then become spindle-shaped mesenchymal cells. This review lays emphasis on studying the cell morphogenesis, makers and molecular mechanism regulation about EMT, discussing the relationship between the EMT and the cancer development and metastasis.

CD133 and membrane microdomains:Old facets for future hypotheses

Understanding all facets of membrane microdomains in normal and cancerous cells within the digestive tract is highly important,not only from a clinical point of view,but also in terms of our basic knowledge of cellular transformation.By studying the normal and cancer stem cell-associated molecule CD133 (prominin-1),novel aspects of the organization and dynamics of polarized epithelial cells have been revealed during the last decade.Its association with particular membrane microdomains is highly relevant in these contexts and might also offer new avenues in diagnosis and/or targeting of cancer stem cells.

Effects of saponin from the seed of Litchi chinensis Sonn on TGF-β1, FN and SOCS-1 in renal tubular epithelial cells under high glucose

Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn(SLS)on the growth and apoptosis of human kidney epithelial cells(HKC)cultured in high glucose.Methods:HKC were cultured in DMEM/F12 medium supplemented with 30 mmol/L glucose and treated with or without SLS.In the normal group,isometric DMEM/F12 medium with 5.5mmol/L glucose was added.The secretion of TGF-β1 and fibronectin(FN)were detected by ELISA.Cell apoptosis was detected by the method of Annexin V-FITC/PI double staining.Western blot was used to detect the level of suppressor of cytokine signaling-1(SOCS-1).Results:The result of ELISA showed that the secretion of TGF-β1 and FN was decreased in SLS groups compared with those in 30 mmol/L glucose treated group(P<0.05).There were more cells apoptosis in 30 mmol/L glucose treated group than that in the normal group(P<0.01).Compared with the 30 mmol/L glucose treated group,the apoptosis of HKC were significantly decreased in SLS groups(P<0.01).Western blot showed that the level of SOCS-1 in high glucose+SLS group was decreased(P<0.01),compared with the high glucose group.Conclusion:SLS can reduce the secretion of TGF-β1 and FN in HKC by reducing the deposition of extracellular matrix.SLS also significantly reduced the apoptosis of HKC by inhibiting the level of SOCS-1.These results suggest the roles of SLS in preventing the progress of glomerular sclerosis.

Targeting of RhoE inhibits epithelial-mesenchymal transition during colorectal cancer cell migration

Objective Despite microRNA （miR-200b） being proved to promote the proliferation of colorectal cancer （CRC） cells, the relationship between miR-200b and epithelial-mesenchymal transition （EMT） of CRC cells remains poorly understood. The aim of the study was to investigate the relationship between miR-200b and EMT during CRC cell migration. Methods The effect of miR-200b on EMT-associated markers E-cadherin and vimentin was evaluated by western blot in CRC cells （SW620 and HT-29） by treatment with miR-200b mimics and inhibitors. A lucifer- ase reporter assay was employed to detect downstream targets of miR-200b. Transwell migration assays were used to detect CRC cell migration. Results Westem blots revealed that treatment with miR-200b mimics led to up-regulation of E-cadherin and down-regulation of vimentin, metalloproteinase （MMP）-9, and MMP-2, whereas treatment with miR- 200b inhibitor exhibited opposite effects on expression of E-cadherin and vimentin. Luciferase reporter assays demonstrated that RhoE （RND3） was targeted by miR-200b. Two predicted target sites of miR-200b were present in the 3＇-UTR of RhoE. Predicted target site 1 was from nucleotides 1584 to 1591, and site 2 was from nucleotides 1729 to 1735. RhoE knockdown cell lines were also established to investigate the impact of RhoE and miR-200b on EMT and cell migration. RhoE knockdown enhanced the effect of miR- 200b mimics, up-regulating E-cadherin and down-regulating vimentin. RhoE knockdown also inhibited cell migration. Furthermore, miR-200b mimic treatment further promoted the inhibitory effect of RhoE knock- down on cell migration.

Relationship between epithelial to mesenchymaltransition and chemoresistance of lung cancer

Objective： The aim of this study was to explore the correlation between epithelial to mesenchymal transition （EMT） and chemoresistance of non-small-cell lung cancer （NSCLC）. Methods： In vitro, the drug resistance index of cisplatin resistant lung adenocarcinoma cell line （A549/DDP） was detected by CCK-8 assay; the morphological change between A549/ DDP cells and lung adenocarcinoma cells （A549） was observed by phase contrast microscope; expression of EMT markers （including E-cadherin and vimentin） and resistance protein, excision repair cross-complementing 1 （ERCC1） was detected by immunocytochemistry. The expression of E-cadherin, vimentin and ERCC1 was investigated by immunohistochemistry in 120 cases of NSCLC, half of that were treated with pre-operative neoadjuvant chemotherapy （neoadjuvant chemotherapy group）, and the other underwent surgery alone （simple surgery group）. Results： There was a significant difference between the ICso （half maximal inhibitory concentration） of A549/DDP cells （5.20） and A549 cells （1.88） （P 〈 0.05）, and the drug resistance index of A549/DDP cells was 2.77. Compared with A549 cells, A549/DDP cells increased expression of ERCC1 （P 〈 0.05）. Moreover, A549/DDP cells showed morphological and phenotypic changes consistent with EMT： with spindle-shaped morphology, and decreased expression of E-cadherin and increased expression of vimentin. Immunohistochemistry showed significant positive correlation between the expression of ERCCI and vimentin （r = 0.496, 0.332, P 〈 0.05）, and significant negative correlation between the ERCCI and E-cadherin （r = -0.403, -0.295, P 〈 0.05） in neoadjuvant chemotherapy group and simple surgery group. In addition, compared with simple surgery group, the expression of ERCC1 （P = 0.003） and vimentin （P = 0.004） was significantly increased, and the expression of E-cadherin was decreased in neoadjuvant chemotherapy group （P = 0.032）. Cenclusion： A549/DDP cells acquired cisplatin-resistance and occurred EMT simultaneously; the phenomenon of chemoresistance and EMT was caused more easily in neoadjuvant chemotherapy group. As such, we further confirmed the close correlation between chemoresistance and EMT of NSCLC, and provided theoretical basis for the targeting therapy with EMT regulatory factor for chemoresistant NSCLC patients.

Induction of epithelial-mesenchymal transition (EMT) in human hepatocellular carcinoma after radiotherapy

Objective: Epithelial-mesenchymal transition (EMT) is a critical early event for the invasion and metastasis of many carcinomas. In the present study, we examined EMT markers in the residual cancer cells of hepatocellular carcinoma (HCC) after radiotherapy. Methods: Eight patients with large HCC who underwent hepatectomy with preoperative radiothera- py were studied. The expressions of E-cadherin and vimentin were determined immunohistochemically in the residual cancer cells of HCC following radiotherapy, and also in the pre-radiotherapy biopsy cancer cells. Results: Histological analysis showed that some residual cancer cells of HCC displayed an elongated spindle or fibroblast-like shape. The expression of E- cadherin was markedly reduced or negative in the spindle residual cancer cells, but the expression of vimentin significantly in- duced. However, the above changes were not found in the pre-radiotherapy biopsy cancer cells. Conclusion: EMT is induced in the residual cancer cells of HCC following radiotherapy, which may facilitate the systemic dissemination of cancer cells.

TiO_2 composite nanotubes embedded with CdS and upconversion nanoparticles for near infrared light driven photocatalysis

We report a colloidal process to coat a layer of TiO2onto SiO2composite nanofibers containing embedded CdS and upconversion nanoparticles(UCNPs).The SiO2composite nanofibers were fabricated by electrospinning.To improve the energy transfer efficiency,UCNPs and CdS nanoparticles were bound in close proximity to each other within the SiO2matrix.β‐NaYF4:Yb(30%),Tm(0.5%)@NaYF4:Yb(20%),Er(2%)core–shell nanoparticles were used as nanotransducers for near infrared light.These nanoparticles exhibited enhanced upconversion fluorescence compared withβ‐NaYF4:Yb(30%),Tm(0.5%)orβ–NaYF4:Yb(30%),Tm(0.5%)@NaYF4nanoparticles.The morphologies,size and chemical compositions have been extensively investigated using field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X‐ray diffraction(XRD)and X‐ray photoelectron spectra(XPS),respectively.The TEM images showed that the TiO2composite nanotubes were embedded with a large amount of UCNPs and CdS nanoparticles.The composite TiO2nanotubes degraded more than90%of rhodamine B(RhB)dye during20min of irradiation by simulated solar light.In particular,more than50%of RhB was decomposed in70min,under irradiation of near infrared light(NIR).This high degradation was attributed to the full spectrum absorption of solar light,and the enhanced transfer efficiency for near infrared light.The as‐prepared nanostructures can harness solar energy,and provide an alternative to overcome energy shortages and environmental protection.

Epithelial-Mesenchymal Transitions and the Expression of Twist in MCF-7/ADR, Human Multidrug-Resistant Breast Cancer Cells

OBJECTIVE To study the expression levels of Twist and epithelialmesenchymal transitions in multidrug-resistant MCF-7/ADR breast cancer cells, and to study the relationship between multidrug resistance （MDR） and metastatic potential of the cells. METHODS RT-PCR, immunohistochemical and Western blotting methods were used to examine the changes of expression levels of the transcription factor Twist, E-cadherin and N-cadherin in the MCF-7 breast cancer cell line and its multidrug-resistant variant, MCF-7/ADR. RESULTS In MCF-7 cells, the expression of E-cadherin can be detected, but there is no expression of Twist or N-cadherin. In MCF-7/ADR cells, E-cadherin expression is lost, but the expression of two other genes was significantly positive. CONCLUSION Epithelial-mesenchymal transitions induced by Twist, may have a relationship with enhanced invasion and metastatic potential during the development of multidrug-resistant MCF-7/ADR breast cancer cells.