查找使用阿拉丁产品的科研文献

Phonon-assisted energy back transfer-induced multicolor upconversion emission of Gd2O3:Yb3+/Er3+ nanoparticles under near-infrared excitation

Jun Liu,Huawei Deng,Zhanyun Huang,Yueli Zhang,Dihu Chen,Yuanzhi Shao

Manipulation of upconversion (UC) emission is of particular importance for multiplexed bioimaging. Here, we precisely manipulate the UC color output by utilizing the phonon-assisted energy back transfer (EBT) process in ultra-small (sub-10 nm) Gd2O3:Yb3+/Er3+ UC nanoparticles (UCNPs). We synthesized the Gd2O3:Yb3+/Er3+ UCNPs by adopting the laser ablation in liquid (LAL) technique. The synthesized Gd2O3:Yb3+/Er3+ UCNPs are small spherical and monoclinic structures. Continuous color-tunable (from green to red) UC fluorescence emission is achieved by increasing the concentration of Yb3+ ions from 0 to 15 mol%. A phonon-assisted energy back transfer (EBT) process from Er3+ (4S3/2 → 4I13/2) to nearby Yb3+ (2F7/2 → 2F5/2), which can significantly enhance red emission at 672 nm and decrease green emission, is responsible for the color-tunable UC emission by increasing the Yb3+ concentration in Gd2O3:Yb3+/Er3+ UC nanoparticles.

Dual-color fluorescence imaging and magnetic resonance imaging of Gd2O3:Dy3+ nanoparticles synthesized by laser ablation in water

Deng Huawei,Liu Jun,Zhang Hang,Li Chaorui,Liu Zhen,Chen Dihu

Multimodal imaging has attracted tremendous attention in biotechnology and nanomedicine applications. Monoclinic Gd 2 O 3 :Dy 3+ nanoparticles (NPs) with dual-color fluorescence imaging (FI) and magnetic resonance imaging (MRI) have been successfully synthesized by employing laser ablation in liquid (LAL) technique. The synthesized nanoparticles can be used as yellow fluorescence nanoprobe as well as blue ones due to their sharp and strong yellow and blue emissions. Magnetic resonance imaging (MRI) measurement shows that the longitudinal relaxivity (r 1 ) of the Gd 2 O 3 :1%Dy 3+ NPs is 4.5 times higher than that of the commercial Gd-DTPA. The experiment of in vitro cell fluorescence imaging and magnetic resonance imaging of female Balb/c mouse indicates that the Gd 2 O 3 :Dy 3+ NPs synthesized by LAL technique are promising candidates of dual-color FI nanoprobe and MRI contrast agent in further clinical applications.

Fabrication of Multifunctional Gd2O3/Au Hybrid Nanoprobe via a One-Step Approach for Near-Infrared Fluorescence and Magnetic Resonance Multimodal Imaging in Vivo

Shao-Kai Sun,Lu-Xi Dong,Yang Cao,Hao-Ran Sun,Xiu-Ping Yan

Facile fabrication of multimodal imaging probes is highly desired for bioimaging application due to their integrated advantages of several imaging modalities. Here, we report a simple and one-step mild strategy to fabricate a multifunctional Gd2O3/Au hybrid nanoprobe. Bovine serum albumin (BSA) was used as the template in the biomineralization synthesis. The fabricated BSA-Gd2O3/Au nanoprobe showed excellent chemical stability, intense near-infrared (NIR) fluorescence, and good magnetic resonance imaging (MRI) ability. The multimodal imaging potential of the prepared multifunctional nanoprobe was demonstrated by successful NIR fluorescent and magnetic resonance blood pool imaging. Further modification of BSA-Gd2O3/Au with arginine–glycine–aspartic acid peptide c(RGDyK) (RGD) enabled the nanoprobe for targeted tumor imaging in vivo.

Janus Dual Self-Strengthening Structure of Bi2O3/Gd2O3 Nanofibrous Membranes for Superior X-Ray Shielding

Li Xu,Xinyu Zhang,Liqian Huang,Jianyong Yu,Yang Si,Bin Ding

Bi 2 O 3 /rare earth oxide biphasic absorbers are attractive for high-efficiency X-ray shielding due to the complementary X-ray absorption effects. However, its application is severely hindered by poor interphasic contact. Here, a new Janus interface engineering strategy is reported for the construction of continuous and flexible Bi 2 O 3 /Gd 2 O 3 crystal nanofibrous membranes (FJNMs) with micro/nano dual self-strengthening interphasic adhesion. This strategy facilitates online micro-interlocking between Bi 2 O 3 /Gd 2 O 3 nanofibers and in situ nano-grain fusion between Bi 2 O 3 /Gd 2 O 3 crystals, significantly enhancing the adhesive strength at the Bi 2 O 3 /Gd 2 O 3 interface. Additionally, the synergistic shielding effect from Bi 2 O 3 /Gd 2 O 3 absorption and multiple reflections in Bi 2 O 3 and Gd 2 O 3 crystal lattices make the nanofibrous membranes a superior X-ray radiation barrier. The FJNMs demonstrate integrated features of exceptional X-ray shielding efficiency (91%–100%), robust interfacial adhesion (lap-shear strength >3.8 MPa), prominent flexibility, lightweight, and outstanding breathability. The design concepts of fibrosing biphasic absorber assemblies pave the way for asymmetrically assembling biphasic materials, setting the stage for a fundamental shift in next-generation radiation shielding materials.

Long-circulating Gd2O3:Yb3+, Er3+ up-conversion nanoprobes as high-performance contrast agents for multi-modality imaging

Zhen Liu,Fang Pu,Sa Huang,Qinghai Yuan,Jinsong Ren,Xiaogang Qu

Due to their unique electric, magnetic, and optical properties, engineered nanostructures have been applied to provide diagnostic, therapeutic, as well as prognostic information about the status of disease. In this study, we report a multifunctional nanoprobe based on PEGylated Gd 2 O 3 :Yb 3+ , Er 3+ nanorods (denoted as PEG-UCNPs) for in vivo up-conversion luminescence (UCL), T 1 -enhanced magnetic resonance (MR), and X-ray computed tomography (CT) multi-modality imaging. A facile and large-scale hydrothermal system combining the merits of an in situ thermal decomposition method and a surface-modified approach is introduced to construct high-quality PEG-UCNPs. By grafting PEG molecules on the surface of PEG-UCNPs, the nanostructures possess excellent stability against in vivo environment and hold long blood circulation time. Cell-cytotoxicity assay, hemolyticity, as well as post-injection histology, hematology, and inflammation analysis further demonstrate their non-cytotoxic character and indicate further in vivo application. In detail, the capability of PEG-UCNPs as high-performance contrast agents for UCL/MR/CT imaging is evaluated successfully through small-animal experiments. Additionally, pharmacokinetics, biodistribution, and clearance route are studied after intravenous injection in a mouse model, reflecting their overall safety.

Gd2O3-MgO nanocomposites for mid-wave infrared applications: the influence of Gd2O3 phase on microstructure, optical, mechanical, and thermal properties

Qian Kaichen,Fan Jintai,Shen Zongyun,Li Kai,Zhou Weiwen,Feng Minghui,Jiang Benxue,Zhang Long

The influence of Gd 2 O 3 phase on microstructure, optical, mechanical and thermal properties in Gd 2 O 3 -MgO nanocomposite ceramics was investigated. A self-propagating high-temperature synthesis (SHS) method was adopted to synthesize Gd 2 O 3 -MgO nanopowders. The pressureless sintering and hot isostatic pressing (HIP) technique were applied to obtain IR-transparent composite ceramics. The Gd 2 O 3 can be stabilized as the cubic structure with 10 at% Y-doping in Gd 2 O 3 -MgO nanocomposite ceramics (named GYM). Optical and mechanical properties of the GYM were compared with the Gd 2 O 3 -MgO without Y-doping samples (named GM) in which Gd 2 O 3 was monoclinic. The flexural strength, emittance of Gd 2 O 3 -MgO nanocomposite ceramics at high temperature were measured for the first time as far as we know. The comparison demonstrated that the GM exhibiting a more promising potential application performance for MWIR windows, with an in-line transmittance of 79.2–83.3% at 3–5 μm, Vickers hardness of 9.6 GPa, flexural strength of 508 MPa, emissivity of 0.02 at 4 μm (800 ℃) and the Hasselman mild-thermal-shock figure of merit R’ =2.0.

Experimental investigation of phase equilibrium in the Gd2O3 - NiO, NiO - ZrO2 and Gd2O3 - NiO - ZrO2 systems at 1773 K and 1573 K

Jingkai Zhou,Gang Qu,Dandan Huang

A comprehensive phase equilibria investigation was conducted in the Gd 2 O 3 - NiO - ZrO 2 system and its binary subsystems (Gd 2 O 3 - NiO and NiO - ZrO 2 ) at 1773 K and 1573 K via solid-phase reaction approach. The NiO - ZrO 2 binary system was initially studied between 1373 K and 1773 K, and the decreased martensitic transition temperatures (1236 K) were determined, confirming Ni 2+ stabilization of t'-ZrO 2 . Homogeneity ranges for Gd 3+ and Zr 4+ in NiO demonstrated minimal temperature dependence. No intermetallic compounds were observed in these subsystems, but a new ternary compound NiO·ZrO 2 ·3Gd 2 O 3 (τ) was identified in the ternary system. Isothermal phase equilibria of the ternary system revealed extended three-phase regions (T + Fl + Hl, Fl + C+ τ etc.) and solubility variations with temperature. Based on experimental data and literature assessments, phase diagrams for the subsystems and ternary isothermal sections were constructed with high reliability.

Revisiting the factors influencing the magnetic resonance contrast of Gd2O3 nanoparticles

Yanyue Liu,Yingfan Dai,Haifeng Li,Dida Duosiken,Na Tang,Kang Sun,Ke Tao

Gadolinium oxide nanoparticles (GONs) have the potential to be one of the best candidates for the contrast agents of magnetic resonance imaging. Even though the influence of parameters on the relaxation has been substantially demonstrated, the variation of the r1 of GONs with a similar structure and surface chemistry implied our limited understanding. We herein synthesized GONs with adjustable size, shape, and crystallinity, modified them with a series of molecules with different acidities, and recorded their r1 values and imaging contrast. Our results showed that the isoelectric point could be regarded as an indicator of the relaxation covering the influence of both surface modification and size, which highlighted the impact of protons dissociated from the contrast agents. We further showed that the nanoparticles with lower crystallinity possess higher relaxivity, and this phenomenon manifested significantly under a low field. Our work clarified that the longitudinal relaxivity of Gd2O3 nanoparticles is sensitively dependent on the numbers of H+ generated from the surface and in the environment, which may shed light on developing high-performance nanoparticulate T1 contrast agents.

Preparation and characterization of nanosphere and nanorod Gd2O3:Tb3+ by polyol route

Meigui Ou,Huina Qiao,Rong Fu,Yanyan Hu,Chunlin Yang,Hao Yin

A pH-Responsive Yolk-Like Nanoplatform for Tumor Targeted Dual-Mode Magnetic Resonance Imaging and Chemotherapy

Xiao Sun,Ruohong Du,Li Zhang,Guilong Zhang,Xiaojia Zheng,Junchao Qian,Xiaohe Tian,Jiewen Zhou,Jiacai He,Yuanyin Wang,Yiqun Wu,Kai Zhong,Dongqing Cai,Duohong Zou,Zhengyan Wu

Incorporation of T1 and T2 contrast material in one nanosystem performing their respective MR contrast role and simultaneously serving as an efficient drug delivery system (DDS) has a significant potential application for clinical diagnosis and chemotherapy of cancer. However, inappropriate incorporation always encountered many issues, such as low contact area of T1 contrast material with water-proton, inappropriate distance between T2 contrast material and water molecule, and undesirable disturbance of T2 contrast material for T1 imaging. Those issues seriously limited the T1 or T2 contrast effect. In this work, we developed a yolk-like Fe3O4@Gd2O3 nanoplatform functionalized by polyethylene glycol and folic acid (FA), which could efficiently exert their tumor targeted T1–T2 dual-mode MR imaging and drug delivery role. First, this nanoplatform possessed a high longitudinal relaxation rate (r1) (7.91 mM–1 s–1) and a stronger transverse relaxation rate (r2) (386.5 mM–1 s–1) than that of original Fe3O4 (268.1 mM–1 s–1). Second, cisplatin could be efficiently loaded into this nanoplatform (112 mg/g) and showed pH-responsive release behavior. Third, this nanoplatform could be effectively internalized by HeLa cells with time and dosage dependence. Fourth, the FA receptor-mediated nanoplatform displayed excellent T1–T2 dual mode MR contrast enhancement and anticancer activity both in vitro and in vivo. Fifth, no apparent toxicity for vital organs was observed with systemic delivery of the nanoplatform in vivo. Thus, this nanoplatform could be a potential nanotheranostic for tumor targeted T1–T2 dual-mode MR imaging and chemotherapy.

Influence of Gd2O3 on the microstructure and properties of transparent MgAl2O4: Cr3+ ceramic

Yan Hao,Yibo Zhang,Biao Liu,Kuibao Zhang

In this work, MgAl 2 O 4 : Cr 3+ transparent ceramics have been synthesized by the hot press sintering techniques, and the effect of the sintering aid Gd 2 O 3 and its content on the densification, microstructure, and optical, photoluminescence was studied and discussed. The relative density reached 99.29% with 0.8 wt% Gd 2 O 3 as a sintering aid, and the optical transmittance at 686 nm and 1446 nm were approximately 76%. As Gd 2 O 3 content continued to increase, the grain size of the ceramics became smaller and uniform, accompanied by some pores with the size of ～1 μm. The ceramics with 4.0 wt% Gd 2 O 3 showed a higher transmittance, of 82% at 1446 nm. Additionally, Gd 2 O 3 was helpful for Cr 3+ in the sites of octahedral symmetry, which increased the quantum yield. The quantum yield of MgAl 2 O 4 : Cr 3+ with 0.8 wt% Gd 2 O 3 was about 0.175, which was 36% higher than that of ceramic without Gd 2 O 3 . In short, the sintering aid Gd 2 O 3 not only contributed to improving the densification, homogenizing the grain size, and heightening the optical transmittance but also enhanced the quantum yield of Cr 3+ .

Phase relations in the Gd2O3-Sm2O3-ZrO2 system: Experimental studies and thermodynamic modeling

Yurong Song,Gang Qu,Xi Li,Dandan Huang

Sm 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 are two promising transparent ceramic materials with high density and effective atomic number. However, the phase diagram of Gd 2 O 3 -Sm 2 O 3 -ZrO 2 system has not been systematically studied. To determine the phase relationship of the ternary system Gd 2 O 3 -Sm 2 O 3 -ZrO 2 at 1600°C and 1400°C, a serious of ceramic samples were prepared and studied by X-ray diffraction, scanning electron microscope , and electron probe microanalysis . In the range of 66.6 mol.% ZrO 2 , the solubility of Gd 2 O 3 is 20–22.5 mol.% at 1600°C, and the binary intermediate phases Sm 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 form a continuous solid solution at 1400°C. Using the experimental data as a foundation, thermodynamic modeling was performed using the approach. Based on the experimental data, the mixing parameters of fluorite , B and C phases were optimized, and thermodynamic modeling was performed using the CALPHAD (CALculation of PHAse Diagram) method. For the first time, a self-consistent database for Gd 2 O 3 -Sm 2 O 3 -ZrO 2 ternary system was established.