Fibroblast activation protein (FAP), which is expressed on the cell membranes of fibroblasts in most solid tumors, has become an important target for tumor diagnosis and treatment. However, previously reported Tc-labeled FAPI-04 complexes have high blood uptake, limiting their use in the clinic. In this work, six Tc-labeled FAPI-46 derivatives with different linkers (different amino acids, peptides, or polyethylene glycol) were prepared and evaluated.
View Article and Find Full Text PDFWhen developing novel radiopharmaceuticals, a linker moiety between the chelator and targeting vector can have a crucial influence on adjusting the affinity of the tracer and its biodistribution in organisms. To develop novel Tc-labelled hypoxia imaging radiotracers, in this study, five isocyanide-containing 2-nitroimidazole derivatives with different linkers (L1, L2, L3, L4 and L5) were synthesised and radiolabelled with technetium-99m to obtain five stable Tc-complexes ([Tc]Tc-L1, [Tc]Tc-L2, [Tc]Tc-L3, [Tc]Tc-L4 and [Tc]Tc-L5). Corresponding rhenium analogues of [Tc]Tc-L1 were synthesised and suggested the structures of these Tc-complexes would be a monovalent cation with a technetium (I) core surrounded by six ligands.
View Article and Find Full Text PDFThis paper presents a simulation study to demonstrate that the contrast recovery coefficients (CRC) and detectability of small lesions of a one-meter-long positron emission tomography (PET) scanner can be further enhanced by the integration of high resolution virtual-pinhole (VP) PET devices. The scanner under investigation is a Siemens Biograph Vision Quadra which has an axial field-of-view (FOV) of 106 cm. The VP-PET devices contain two high-resolution flat panel detectors, each composed of 2 × 8 detector modules each of which consists of 32 × 64 lutetium-oxyorthosilicate crystals (1.
View Article and Find Full Text PDFBackground: The aim of this study was to investigate the immunogenicity and safety of the enterovirus 71 vaccine (EV71 vaccine) administered alone or simultaneously.
Methods: A multi-center, open-label, randomized controlled trial was performed involving 1080 healthy infants aged 6 months or 8 months from Shandong, Shanxi, Shaanxi, and Hunan provinces. These infants were divided into four simultaneous administration groups and EV71 vaccine separate administration group.
This paper presents a novel PET geometry for breast cancer imaging. The scanner consists of a 'stadium' (a rectangle with two semi-circles on opposite sides) shaped ring, along with anterior and posterior panels to provide high sensitivity and high spatial resolution for an imaging field-of-view (FOV) that include both breasts, mediastinum and axilla. We simulated this total-breast PET system using GATE and reconstructed the coincidence events using a GPU-based list-mode image reconstruction implementing maximum likelihood expectation-maximization (ML-EM) algorithm.
View Article and Find Full Text PDFComposed of electrocaloric (EC) ceramics and polymers, polymer composites with high EC performances are considered as promising candidates for next-generation all-solid-state cooling devices. Their mass application is limited by the low EC strength, which requires very high operational voltage to induce appreciable temperature change. Here, an all-scale hierarchical architecture is proposed and demonstrated to achieve high EC strength in poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)-based nanocomposites.
View Article and Find Full Text PDFPoly(vinylidene fluoride) (PVDF)-based polymers with excellent flexibility and relatively high permittivity are desirable compared to the traditional bulk ceramic in dielectric material applications. However, the low discharge efficiency (<70%) caused by the severe intrinsic dielectric loss of these polymers result in a decrease in their breakdown strength and other problems, which limit their widespread applications. To address these outstanding issues, herein, we used a stacking method to combine poly(methyl methacrylate) (PMMA) with poly(vinylidene fluoride--hexafluoropropylene) (P(VDF-HFP)) for the synthesis of a series of alternating multilayer films with different layers.
View Article and Find Full Text PDFA novel technique, called augmented whole-body scanning via magnifying PET (AWSM-PET), that improves the sensitivity and lesion detectability of a PET scanner for whole-body imaging is proposed and evaluated. A Siemens Biograph Vision PET/CT scanner equipped with one or two high-resolution panel-detectors was simulated to study the effectiveness of AWSM-PET technology. The detector panels are located immediately outside the scanner's axial field-of-view (FOV).
View Article and Find Full Text PDFPolymer nanocomposite dielectrics, composed of polymer matrices with high breakdown strength and nanofillers with high dielectric constant, can achieve outstanding energy density. However, the great difference of intrinsic surface properties between the polymer and nanofillers will lead to poor compatibility and thus damage the dielectric properties of the composites. Introducing a transition layer to the filler surface can effectively reduce the degree of mismatch.
View Article and Find Full Text PDFNanoporous holey-graphene (HG) shows potential versatility in several technological fields, especially in biomedical, water filtration, and energy storage applications. Particularly, for ultrahigh electrochemical energy storage applications, HG has shown promise in addressing the issue of low gravimetric and volumetric energy densities by boosting of the ion-transport efficiency in a high-mass-loaded graphene electrode. However, there are no studies showing complete control over the entire pore architecture and density of HG and their effect on high-rate energy storage.
View Article and Find Full Text PDFPurpose: We have developed a second-generation virtual-pinhole (VP) positron emission tomography (PET) device that can position a flat-panel PET detector around a patient's body using a robotic arm to enhance the contrast recovery coefficient (CRC) and detectability of lesions in any region-of-interest using a whole-body PET/computed tomography (CT) scanner.
Methods: We constructed a flat-panel VP-PET device using 32 high-resolution detectors, each containing a 4 4 MPPC array and 16 16 LYSO crystals of 1.0 1.
Understanding the breakdown mechanisms of polymer-based dielectrics is critical to achieving high-density energy storage. Here a comprehensive phase-field model is developed to investigate the electric, thermal, and mechanical effects in the breakdown process of polymer-based dielectrics. High-throughput simulations are performed for the P(VDF-HFP)-based nanocomposites filled with nanoparticles of different properties.
View Article and Find Full Text PDFFerroelectric memories are endowed with high data storage density by nanostructure designing, while the robustness is also impaired. For organic ferroelectrics favored by flexible memories, low Curie transition temperature limits their thermal stability. Herein, a ferroelectric random access memory (FeRAM) is demonstrated based on an array of P(VDF-TrFE) lamellae by self-assembly.
View Article and Find Full Text PDFPurpose: We investigated the feasibility of a novel positron emission tomography (PET) system that provides near real-time feedback to an operator who can interactively scan a patient to optimize image quality. The system should be compact and mobile to support point-of-care (POC) molecular imaging applications. In this study, we present the key technologies required and discuss the potential benefits of such new capability.
View Article and Find Full Text PDFThe electrocaloric effect (ECE) refers to reversible thermal changes of a polarizable material upon the application or removal of electric fields. Without a compressor or cooling agents, all-solid-state electrocaloric (EC) refrigeration systems are environmentally benign, highly compact, and of very high energy efficiency. Relaxor ferroelectric ceramics and polymers are promising candidates as EC materials.
View Article and Find Full Text PDFElectrocaloric effect (ECE) is much promising to realize high efficiency and environment friendly solution in solid cooling devices. Relaxor ferroelectrics are good candidates for the materials with high electrocaloric cooling power. In this paper, relaxor ferroelectric Ba(ZrTi)O (BZT, x = 0.
View Article and Find Full Text PDFManipulating microstructures of composites in three dimensions has been a long standing challenge. An approach is proposed and demonstrated to fabricate artificial nanocomposites by controlling the 3D distribution and orientation of oxide nanoparticles in a polymer matrix. In addition to possessing much enhanced mechanical properties, these nanocomposites can sustain extremely high voltages up to ≈10 kV, exhibiting high dielectric breakdown strength and low leakage current.
View Article and Find Full Text PDFPolymer nanocomposite dielectrics with high energy density and low loss are major enablers for a number of applications in modern electronic and electrical industry. Conventional fabrication of nanocomposites by solution routes involves equilibrium process, which is slow and results in structural imperfections, hence high leakage current and compromised reliability of the nanocomposites. We propose and demonstrate that a nonequilibrium process, which synergistically integrates electrospinning, hot-pressing and thermal quenching, is capable of yielding nanocomposites of very high quality.
View Article and Find Full Text PDFPolymers with high dielectric strength and favorable flexibility have been considered promising materials for dielectrics and energy storage applications, while the achievable energy density (U) of polymer is rather limited by the intrinsic low dielectric constant and ferroelectric hysteresis. Polyvinylidene fluoride-trifluoroethylene-chlorofluoroethylene (P(VDF-TrFE-CFE)) with ultrahigh ε of >50 is considered promising in achieving high U of polymer dielectrics. However, P(VDF-TrFE-CFE) only exhibits moderate U due to the early saturation of electrical polarization at low electric field.
View Article and Find Full Text PDFLarge-aspect-ratio composite nanofibers with interior hierarchical interfaces are employed to break the adverse coupling of electric displacement and breakdown strength in flexible poly(vinylidene fluoride-hexafluoropropylene) nanocomposite films, a small loading of 3 vol% BaTiO3@TiO2 nanofibers gives rise to the highestenergy density (≈31.2 J cm(-3)) ever achieved in polymer nanocomposites dielectrics.
View Article and Find Full Text PDFZhongguo Zhong Xi Yi Jie He Za Zhi
July 2013
Malfunctioned gap junctional intercellular communication (GJIC) has been thought associated with malignant transformation of normal cells. However, the role of GJIC-related proteins such as connexins in sustaining the malignant behavior of cancer stem cells remains unclear. In this study, we obtained tumorspheres formed by glioma stem cells (GSCs) and adherent GSCs and then examined their GJIC.
View Article and Find Full Text PDFChemokines and their receptors are actively involved in inflammation, immune responses, and cancer development. Here we report the detection of CD133(+) glioma stem-like cells (GSCs) co-expressing a chemokine receptor CXCR4 in human primary glioma tissues. These GSCs were located in areas adjacent to tumour vascular capillaries, suggesting an association between GSCs and tumour angiogenesis.
View Article and Find Full Text PDFRecent progress in cancer biology indicates that eradication of cancer stem cells (CSCs) is essential for more effective cancer therapy. Unfortunately, cancer stem cells such as glioma stem-like cells (GSLCs) are often resistant to either radio- or chemotherapy. Therefore, screening and development for novel therapeutic modalities against CSCs has been an important emerging field in cancer research.
View Article and Find Full Text PDFZhongguo Zhong Xi Yi Jie He Za Zhi
August 2004