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排序方式: 共有9345条查询结果,搜索用时 31 毫秒
1.
Dr. Behdad Aghelnejad Prof. Geoffrey Bodenhausen Dr. Philippe Pelupessy 《Chemphyschem》2022,23(3):e202100786
Diffusion processes can be followed directly by recording one-dimensional images of a selected slice at variable intervals after selective inversion of the magnetization. The resulting diffusion coefficients of H2O and DMSO are consistent with earlier studies at different temperatures, obtained by monitoring the attenuation of NMR signals as a function of the gradient amplitude in gradient echo sequences. 相似文献
2.
对微结构的制作、微装配系统进行了研究. 采用飞秒激光双光子聚合微加工技术制作有底座、精细的三维立体“拱形”微结构, 其高250μm、长300μm、厚50μm. 将此微结构与实验室自主搭建的二维微装配平台相结合, 利用自主编程的人机交互界面驱动步进电机, 远程操控微装配设备; 将荧光闪烁陶瓷粉末装配到微结构中, 对装配后的微结构进行荧光光谱表征发现, 纯荧光粉末和微结构中的荧光粉末的发射光谱在测量误差范围内基本一致, 表明荧光粉末的光学性质未发生改变. 利用该装置可以将各类微纳米级材料和微结构进行装配, 形成含有不同材料的微结构系统. 相似文献
3.
Yu He Yating Guo Yanbin Yu Peifu Luo Honglong Qiu Guoming Huang 《Particle & Particle Systems Characterization》2021,38(5):2100038
In this study, manganese tellurite (MnTeO3) nanoparticles are developed as theranostic agents for magnetic resonance imaging (MRI)-guided photothermal therapy of tumor. MnTeO3 nanoparticles are synthesized via a simple one-step method. The as-synthesized MnTeO3 nanoparticles with uniform size show good biocompatibility. In particular, MnTeO3 nanoparticles exhibit a high photothermal conversion efficiency (η = 26.3%), which is higher than that of gold nanorods. Moreover, MnTeO3 nanoparticles also have high MRI performance. The longitudinal relaxivity (r1) value of MnTeO3 nanoparticles is determined to be 8.08 ± 0.2 mm −1 s−1, which is higher than that of clinically approved T1-contrast agents Gd-DTPA (4.49 ± 0.1 mm −1 s−1). The subsequent MnTeO3 nanoparticles-mediated photothermal therapy displays a highly efficient ablation of tumor cells both in vitro and in vivo with negligible toxicity. It is demonstrated that MnTeO3 nanoparticles can serve as promising theranostic agents with great potentials for MRI-guided photothermal therapy. 相似文献
4.
本研究探讨3.0T磁共振成像(MRI)结合X线钼靶诊断乳腺恶性肿瘤的价值。采用回顾性研究方法,选取乳腺肿块患者110例162个病灶,给予3.0T MRI及X线钼靶检查。经病理确诊为恶性病变101个;恶性病灶形态不规则、边缘毛刺、时间-信号强度曲线(TIC)类型Ⅲ型和早期增强率≥60%比例明显高于良性病灶(P<0.05),而分叶状比例和表观扩散系数(ADC)值明显低于良性病变(P<0.05);恶性病变X线钼靶表现:形态不规则、钙化、结构不对称和大导管征比例明显高于良性病变(P<0.05);MRI联合X线钼靶诊断乳腺恶性病变的灵敏性、准确性和阴性预测值明显高于MRI诊断(P<0.05)。3.0T MRI检查结合X线钼靶诊断乳腺恶性肿瘤有较好的价值。 相似文献
5.
Three one-dimensional ladder-like coordination polymers consisting of Cd6 metalloring as the building unit, {[Cd4LCl4]·3H2O}n ( 1 ), {[Cd3L(ClO4)(H2O)]ClO4·3H2O}n ( 2 ), and {[Cd6(L)2(NO3)2(CH3OH)(H2O)](NO3)2·2CH3OH·5H2O}n ( 3 ), were solvothermally constructed from a carboxylic functionalized bisazamacrocyclic ligand 4,4′-bis((4,7-bis(2-carboxyethyl)-1,4,7-triazacyclonon-1-yl)methyl)-1,1′-biphenyl (H4L). These compounds dispersed in ethanol show the multiple emissions originating from the monomeric and intramolecularly overlapping biphenyl moieties which could be sensitively quenched by picric acid (PA) and 4-nitrophenol (4-NP) through the effective fluorescence resonance energy transfer process. The differential fluorescent responses of each compound on exposure to PA and 4-NP individually make the convenient ratiometric discrimination of two analytes based on the fluorescent intensity ratio (I320/I360) attainable, and 1 and 2 as ratiometric chemosensors for PA present a broad linear detection range from 4 to 300 μM with detection limits of 0.84 and 0.93 μM, respectively. Furthermore, the blue light emission of 1 under an ultraviolet lamp could be selectively quenched by PA even in the presence of all other interfering nitroaromatic pollutants, which empowers the fast visual detection of PA by naked eye. 相似文献
6.
Jinhua Gao Yuanfang Tao Dr. Jian Zhang Nannan Wang Xin Ji Dr. Jinling He Prof. Yubing Si Prof. Weili Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11246-11256
Our previous discovery suggested that substituents on the 1,7 positions delicately modulate the sensing ability of the meso-arylmercapto boron-dipyrromethene (BODIPY) to biothiols. In this work, the impact of delicate modulations on the sensing ability is investigated. Therefore, 1,7-dimethyl, 3,5-diaryl substituted BODIPY is designed and developed and its conformationally restricted species with a meso-arylmercapto moiety ( DM-BDP-SAr and DM-BDP-R-SAr ) as selective fluorescent probes for Cys. Moreover, the lysosome-target probes ( Lyso-S and Lyso-D ) based on DM-BDP-SAr carrying one or two morpholinoethoxy moieties were developed. They were able to detect Cys selectively in vitro with low detection limits. Both Lyso-S and Lyso-D localized nicely in lysosomes in living HeLa cells and exhibited red fluorescence for Cys. Moreover, a novel fluorescence quenching mechanism was proposed from the calculations by density functional theory (DFT). The probes may go through intersystem crossing (from singlet excited state to triplet excited state) to result in fluorescence quenching. 相似文献
7.
Theo Steininger Jait Dixit Philipp Frank Maksim Greiner Sebastian Hutschenreuter Jakob Knollmüller Reimar Leike Natalia Porqueres Daniel Pumpe Martin Reinecke Matev raml Csongor Varady Torsten Enßlin 《Annalen der Physik》2019,531(3)
NIFTy , “Numerical Information Field Theory,” is a software framework designed to ease the development and implementation of field inference algorithms. Field equations are formulated independently of the underlying spatial geometry allowing the user to focus on the algorithmic design. Under the hood, NIFTy ensures that the discretization of the implemented equations is consistent. This enables the user to prototype an algorithm rapidly in 1D and then apply it to high‐dimensional real‐world problems. This paper introduces NIFTy 3, a major upgrade to the original NIFTy framework. NIFTy 3 allows the user to run inference algorithms on massively parallel high performance computing clusters without changing the implementation of the field equations. It supports n‐dimensional Cartesian spaces, spherical spaces, power spaces, and product spaces as well as transforms to their harmonic counterparts. Furthermore, NIFTy 3 is able to handle non‐scalar fields, such as vector or tensor fields. The functionality and performance of the software package is demonstrated with example code, which implements a mock inference inspired by a real‐world algorithm from the realm of information field theory. NIFTy 3 is open‐source software available under the GNU General Public License v3 (GPL‐3) at https://gitlab.mpcdf.mpg.de/ift/NIFTy/tree/NIFTy_3 . 相似文献
8.
Biomaterial scaffolds are the cornerstone to supporting 3D tissue growth. Optimized scaffold design is critical to successful regeneration, and this optimization requires accurate knowledge of the scaffold's interaction with living tissue in the dynamic in vivo milieu. Unfortunately, non‐invasive methods that can probe scaffolds in the intact living subject are largely underexplored, with imaging‐based assessment relying on either imaging cells seeded on the scaffold or imaging scaffolds that have been chemically altered. In this work, the authors develop a broadly applicable magnetic resonance imaging (MRI) method to image scaffolds directly. A positive‐contrast “bright” manganese porphyrin (MnP) agent for labeling scaffolds is used to achieve high sensitivity and specificity, and polydopamine, a biologically derived universal adhesive, is employed for adhering the MnP. The technique was optimized in vitro on a prototypic collagen gel, and in vivo assessment was performed in rats. The results demonstrate superior in vivo scaffold visualization and the potential for quantitative tracking of degradation over time. Designed with ease of synthesis in mind and general applicability for the continuing expansion of available biomaterials, the proposed method will allow tissue engineers to assess and fine‐tune the in vivo behavior of their scaffolds for optimal regeneration. 相似文献
9.
Dr. Samuel Oger Damien Schapman Dr. Romain Mougeot Dr. Stéphane Leleu Dr. Noëlle Lascoux Dr. Patrice Baldeck Dr. Magalie Bénard Dr. Thibault Gallavardin Dr. Ludovic Galas Dr. Xavier Franck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(46):10954-10964
Epicocconone 1 is a natural chromophore isolated from the fungus Epicoccum nigrum that has shown applications in proteomics and fluorescent microscopy thanks to its unique pro-fluorescence properties. The modification of the skeleton of the natural product by replacing the triene side chain by a fluorenyl scaffold can noticeably increase the fluorophore's absorption coefficient. The synthesis of the analogues of the natural product has been made possible by the use of a palladium-catalyzed carbonylation reaction, allowing the construction of the β-keto-dioxinone key intermediate. Two-photon absorption cross-section measurements of the fluorenyl epicocconone analogues show a structure dependency with values ranging from 60 to 280 GM and live cell imaging show intense staining of intracellular vesicle-like structures around the nucleus. 相似文献