34 research outputs found

    Synthesis of NaYF4:Yb3+, Er3+ upconversion nanoparticles in normal microemulsions

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    An interface-controlled reaction in normal microemulsions (water/ethanol/sodium oleate/oleic acid/n-hexane) was designed to prepare NaYF4:Yb3+, Er3+ upconversion nanoparticles. The phase diagram of the system was first studied to obtain the appropriate oil-in-water microemulsions. Transmission electron microscopy and X-ray powder diffractometer measurements revealed that the as-prepared nanoparticles were spherical, monodisperse with a uniform size of 20 nm, and of cubic phase with good crystallinity. Furthermore, these nanoparticles have good dispersibility in nonpolar organic solvents and exhibit visible upconversion luminescence of orange color under continuous excitation at 980 nm. Then, a thermal treatment for the products was found to enhance the luminescence intensity. In addition, because of its inherent merit in high yielding and being economical, this synthetic method could be utilized for preparation of the UCNPs on a large scale

    Functionalized halloysite nanotube-based carrier for intracellular delivery of antisense oligonucleotides

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    Halloysites are cheap, abundantly available, and natural with high mechanical strength and biocompatibility. In this paper, a novel halloysite nanotube [HNT]-based gene delivery system was explored for loading and intracellular delivery of antisense oligodeoxynucleotides [ASODNs], in which functionalized HNTs [f-HNTs] were used as carriers and ASODNs as a therapeutic gene for targeting survivin. HNTs were firstly surface-modified with γ-aminopropyltriethoxysilane in order to facilitate further biofunctionalization. The f-HNTs and the assembled f-HNT-ASODN complexes were characterized by transmission electron microscopy [TEM], dynamic light scattering, UV-visible spectroscopy, and fluorescence spectrophotometry. The intracellular uptake and delivery efficiency of the complexes were effectively investigated by TEM, confocal microscopy, and flow cytometry. In vitro cytotoxicity studies of the complexes using MTT assay exhibited a significant enhancement in the cytotoxic capability. The results exhibited that f-HNT complexes could efficiently improve intracellular delivery and enhance antitumor activity of ASODNs by the nanotube carrier and could be used as novel promising vectors for gene therapy applications, which is attributed to their advantages over structures and features including a unique tubular structure, large aspect ratio, natural availability, rich functionality, good biocompatibility, and high mechanical strength

    Towards a high-intensity muon source at CiADS

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    The proposal of a high-intensity muon source driven by the CiADS linac, which has the potential to be one of the state-of-the-art facilities, is presented in this paper. We briefly introduce the development progress of the superconducting linac of CiADS. Then the consideration of challenges related to the high-power muon production target is given and the liquid lithium jet muon production target concept is proposed, for the first time. The exploration of the optimal target geometry for surface muon production efficiency and the investigation into the performance of liquid lithium jet target in muon rate are given. Based on the comparison between the liquid lithium jet target and the rotation graphite target, from perspectives of surface muon production efficiency, heat processing ability and target geometry compactness, the advantages of the new target concept are demonstrated and described comprehensively. The technical challenges and the feasibility of the free-surface liquid lithium target are discussed

    Synthesis of NaYF<sub>4</sub>:Yb<sup>3+</sup>, Er<sup>3+ </sup>upconversion nanoparticles in normal microemulsions

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    Abstract An interface-controlled reaction in normal microemulsions (water/ethanol/sodium oleate/oleic acid/n-hexane) was designed to prepare NaYF4:Yb3+, Er3+ upconversion nanoparticles. The phase diagram of the system was first studied to obtain the appropriate oil-in-water microemulsions. Transmission electron microscopy and X-ray powder diffractometer measurements revealed that the as-prepared nanoparticles were spherical, monodisperse with a uniform size of 20 nm, and of cubic phase with good crystallinity. Furthermore, these nanoparticles have good dispersibility in nonpolar organic solvents and exhibit visible upconversion luminescence of orange color under continuous excitation at 980 nm. Then, a thermal treatment for the products was found to enhance the luminescence intensity. In addition, because of its inherent merit in high yielding and being economical, this synthetic method could be utilized for preparation of the UCNPs on a large scale.</p

    Celastrol functions as an emerging manager of lipid metabolism: Mechanism and therapeutic potential

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    Lipid metabolism disorders are pivotal in the development of various lipid-related diseases, such as obesity, atherosclerosis, non-alcoholic fatty liver disease, type 2 diabetes, and cancer. Celastrol, a bioactive compound extracted from the Chinese herb Tripterygium wilfordii Hook F, has recently demonstrated potent lipid-regulating abilities and promising therapeutic effects for lipid-related diseases. There is substantial evidence indicating that celastrol can ameliorate lipid metabolism disorders by regulating lipid profiles and related metabolic processes, including lipid synthesis, catabolism, absorption, transport, and peroxidation. Even wild-type mice show augmented lipid metabolism after treatment with celastrol. This review aims to provide an overview of recent advancements in the lipid-regulating properties of celastrol, as well as to elucidate its underlying molecular mechanisms. Besides, potential strategies for targeted drug delivery and combination therapy are proposed to enhance the lipid-regulating effects of celastrol and avoid the limitations of its clinical application

    Fabrication of Nano Capacitor and its Electrical Properties

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    用逐层组装法在阳极氧化铝模板的纳米孔内制备纳米电容器,其组成为电化学聚合PPy/电沉积TiO2多孔隔膜/化学聚合PPy.该纳米电容器显示了典型的电化学超电容性质,且具有良好的充放电性能.A step-by-step assembling method was developed for preparing nano capacitors using anodic aluminum oxide (AAO) membrane as templates. The nano capacitor consisted of three parts: electrochemically polymerized PPy electrode/ el ectrochemically precipitated porous TiO_(2) separator / chemically polymerized PPy electrode, and demonstrated the charge/discharge behavior as a typical electrochemical supercapacitor with good cyclic ability.作者联系地址:复旦大学化学系,复旦大学化学系,复旦大学化学系,复旦大学化学系 上海200433 ,上海200433 ,上海200433 ,上海200433Author's Address: Department of Chemistry, Fudan University, Shanghai 200433,Chin

    Present Status, Challenges, and Prospects of Dihydromyricetin in the Battle against Cancer

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    Dihydromyricetin (DHM) is a natural flavonoid compound extracted from Ampelopsis grossedentata that has been used for centuries in traditional Chinese medicine. DHM has attracted intensive attention due to its numerous beneficial activities, such as hepatoprotection, cardioprotection, antioxidant, and anti-inflammation. In addition, DHM inhibits the progression of cancers such as lung cancer, hepatocellular cancer, breast cancer, melanoma, and malignant reproductive systems through multiple mechanisms, including antiangiogenesis, antiproliferation, apoptosis, and inhibition of invasion and migration. Notably, DHM also activates autophagy at different levels, exerting a dual-regulatory effect on cancers. Mechanistically, DHM can effectively regulate mammalian target of rapamycin (mTOR), noncoding RNA-mediated signaling, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway, nuclear factor-&kappa;B (NF-&kappa;B), p53, and endoplasmic reticulum stress (ER stress)-driven signaling in different types of cancers. DHM has also been shown to have inhibitory effects on various regulators that trigger epithelial&ndash;mesenchymal transition (EMT). Furthermore, DHM exhibits a remarkable anticancer reversal ability when used in combination with drugs such as adriamycin, nedaplatin, and other drugs. However, the low bioavailability of DHM limits its potential applications, which are improved through structural modification and the exploration of novel dosage forms. Therefore, DHM may become a promising candidate for treating malignancies alone or combined with conventional anticancer strategies used in clinical practice

    Comparison of the Electrochemical Reactivity of Electrodes Modified by Carbon Nanotubes with Different Sizes

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    制备不同尺寸的多壁碳纳米管(MWNT)修饰电极,应用循环伏安法研究了相同管径、不同管长和相同管长、不同管径的多壁碳纳米管修饰电极在K3Fe(CN)6溶液中的电化学行为及其对尿酸、多巴胺等生物分子的电催化作用,以及尺寸效应对碳纳米管修饰电极电化学活性的影响规律.结果显示,在同一条件下,短管的MWNT比长管的更能有效促进K3Fe(CN)6的电子传递,更有利于对生物分子的电催化;管径对它的电化学行为及生物电催化活性影响较小,无明显规律.主要原因在于碳纳米管管端、管壁的不同电化学活性.The electrochemical activity of multi-walled carbon nanotubes(MWNTs) with different sizes,including four different MWNTs with the same length and different diameter,two different MWNTs with the same diameter and different length has been assessed and compared.The various MWNTs modified electrodes were prepared by immobilizing the suitable amount of MWNTs onto a glassy carbon electrode,and their voltammetric responses to ferricyanide,uric acid and dopamine were examined.The corresponding cyclic voltammetric data was showed that the electrochemical and electrocatalytic activities are depended on the nanotube length.The electrochemical reactivity of short MWNT(S-MWNT) is better than that of long MWNT(L-MWNT),which may be mainly attributed to the existence of the more open ends of the S-MCNT relative to L-MWNT.作者联系地址:上海师范大学生命与环境科学学院化学系,上海师范大学生命与环境科学学院化学系,上海师范大学生命与环境科学学院化学系 上海200234,上海200234,上海200234Author's Address: Dept.of Chemistry,College of Life and Environment Science,Shanghai Normal University,Shanghai 200234,Chin
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