Positive Contrast Imaging of SPIO Nanoparticles

It is advantageous to achieve positive contrast images instead of negative contrast images in superparamagnetic iron-oxide (SPIO) nanoparticles-based MR imaging in order to distinguish the signal surrounding SPIO nanoparticles from the dark signal due to local field inhomogeneity and the artifacts due to tissue interface and background noise, eliminate the inherent defects in the traditional MRI such as partial-volume effects and large void volume for reliable visualization, and increase contrast-to-noise ratio. Many methods generating positive signal with SPIO nanoparticles have been developed in the last decade. This paper provides an overview of current visualization methods and states their advantages and disadvantages. In practice, these techniques have been widely applied to cell labeling and disease diagnosis and monitoring. However, there is still a need for an ideal method to achieve both accuracy and sensitivity

Cost/Benefit Assessment of a Smart Distribution System With Intelligent Electric Vehicle Charging

In the near future, with more distributed generators connected and new demands arising from the electrification of heat and transport in the distribution networks, infrastructure will become ever more stressed. However, building costly new circuits to accommodate generation and demand growth is time-consuming and environmentally unfriendly. Therefore, active network management (ANM) has been promoted in many countries, aiming to relieve network pressure. Previous research in ANM was focused on distribution areas with significant renewable penetration, where ANM reduced network pressure through significantly enhanced generation curtailment strategies rather than adopting traditional asset investment. This paper proposes the use of electric vehicles (EVs) as responsive demand to complement network stress relief that was purely based on generation curtailment. It is achieved by allowing EVs to absorb excessive renewable generation when they cause network pressure, and it thus can provide additional measures to generation curtailment strategies. The approach is illustrated on a practical extra-high voltage distribution system. The analyses clearly demonstrate the combined management of demand and generation is superior to previous sole generation management. The combined management strategy can achieve 7.9% improvement in utilization of renewable energy, and subsequently increase the net investment profit by £566 k

PARK16 rs708730 Polymorphism Decreases Parkinson’s Disease Risk in European Ancestry Population: A Meta-analysis

Parkinson’s disease (PD) is a complex fatal chronic neurodegenerative disease most common in elderly people. The early genome-wide association studies (GWAS) found that the minor allele variant of PARK16 rs708730 polymorphism is a significant protective factor for PD in Caucasian populations. However, these results cannot be repeated by the following studies in Caucasian populations and other populations. We considered that the inconsistency of the findings may be caused by the small-scale samples or the heterogeneity among different populations. Therefore, in this study, we synthesized the previous related GWAS studies through three authoritative sources, and used the large-scale samples (10,645 PD cases and 30,499 controls) to reevaluate the association between rs708730 polymorphism and PD. The results showed that there is no association between them in Asian ancestry population. While, in European ancestry population, we found that the minor allele variant (G) of rs708730 polymorphism is significantly associated with a decreased risk of PD. Collectively, our findings further verified the association of rs708730 with PD and show its genetic heterogeneity among different populations, which can help to develop a better understanding of the PD’s pathogenesis

Preparation and characterization of PLA ultrasound contrast agents by combining an ultrasound method and a Shirasu Porous Glass (SPG) membrane emulsification technique

The ultrasound contrast agent based on a poly lactic acid (PLA) was prepared by combining an ultrasound method and a Shirasu Porous Glass (SPG) membrane emulsification technique. An aqueous phase containing ammonium bicarbonate was used as the internal water phase (WO, and PLA and Span 80 were dissolved in a solvent of dichloromethane (DCM), which was used as the oil phase (0). These two solutions were probe sonicated to form a W(1)/O primary emulstion. The primary emulsion was permeated through the uniform pores (1.1 mu m) of an SPG membrane into the external water phase (W(2)) by the pressure of nitrogen gas to form the uiniform W(1)/O/W(2) droplets. After DCM was evaporated, the hardened PLA microcapsules were further formulated into a lyophilized powder containing decafluorobutane gas. SEM image demonstrated that the PLA microcapsules were sphere-shaped and internally hollow with an average diameter ranging from 1.99 to 3.58 mu m. In vitro, the PLA contrast agents showed high acoustic enhancement properties, the enhancement increased nonlinearly with dose, and the minimal loss (less than 5 dB) of signal was observed over 20 min of analysis at 37 degrees C, the maximum acoustic enhancement was 45 dB, which significantly higher (p<0.01) compared to a value of 28 dB for those prepared by a conventional solvent evaporation method. In conclusion, the hollow PLA microcapsules prepared by the novel method have the characteristics desirable for an intravenously administered ultrasound contrast agents

Synthesis of magnetic, fluorescent and mesoporous core-shell-structured nanoparticles for imaging, targeting and photodynamic therapy

A synthetic method to prepare novel multifunctional core-shell-structured mesoporous silica nanoparticles for simultaneous magnetic resonance (MR) and fluorescence imaging, cell targeting and photosensitization treatment has been developed. Superparamagnetic magnetite nanoparticles and fluorescent dyes are co-encapsulated inside nonporous silica nanoparticles as the core to provide dual-imaging capabilities (MR and optical). The photosensitizer molecules, tetra-substituted carboxyl aluminum phthalocyanine (AlC(4)Pc), are covalently linked to the mesoporous silica shell and exhibit excellent photo-oxidation efficiency. The surface modification of the core-shell silica nanoparticles with folic acid enhances the delivery of photosensitizers to the targeting cancer cells that overexpress the folate receptor, and thereby decreases their toxicity to the surrounding normal tissues. These unique advantages make the prepared multifunctional core-shell silica nanoparticles promising for cancer diagnosis and therapy.NSFC[21021061, 20925103, 20871100]; Fok Ying Tung Education Foundation[121011]; NSF of Fujian Province[2009J06005]; Fundamental Research Funds for the Central Universities[2010121015]; Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministr

Multifunctional Ag@Fe(2)O(3) yolk-shell nanoparticles for simultaneous capture, kill, and removal of pathogen

We combined silver and iron oxide nanoparticles to make unique Ag@Fe(2)O(3) yolk-shell multifunctional nanoparticles by the Kirkendall effect. After the surface functionalization using glucose, the Ag@Fe(2)O(3)-Glu conjugates exhibited both high capture efficiency of bacteria and potent antibacterial activity. The Ag@Fe(2)O(3) yolk-shell nanostructures may offer a unique multifunctional platform for simultaneous rapid detection and capture of bacteria and safe detoxification treatment.National Science Foundation of China[21021061, 81000662]; Fundamental Research Funds for the Central Universities[2010121012]; Program for New Century Excellent Talents in University[NCET-10-0709

Multifunctional Core-Shell Upconverting Nanoparticles for Imaging and Photodynamic Therapy of Liver Cancer Cells

通讯作者地址: Chen, XL (通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 3. Xiamen Univ, Dept Elect Sci, Fujian Key Lab Plasma & Magnet Resonance, Xiamen 361005, Peoples R China 4. Xiamen Univ, Dept Commun Engn, Fujian Key Lab Plasma & Magnet Resonance, Xiamen 361005, Peoples R China 电子邮件地址: [email protected]; [email protected] upconversion nanoparticles (UCNPs) have attracted considerable attention for their application in biomedicine. Here, silica-coated NaGdF4:Yb,Er/NaGdF4 nanoparticles with a tetrasubstituted carboxy aluminum phthalocyanine (AlC4Pc) photosensitizer covalently incorporated inside the silica shells were prepared and applied in the photodynamic therapy (PDT) and magnetic resonance imaging (MRI) of cancer cells. These UCNP@SiO2(AlC4Pc) nanoparticles were uniform in size, stable against photosensitizer leaching, and highly efficient in photogenerating cytotoxic singlet oxygen under near-infrared (NIR) light. In vitro studies indicated that these nanoparticles could effectively kill cancer cells upon NIR irradiation. Moreover, the nanoparticles also demonstrated good MR contrast, both in aqueous solution and inside cells. This is the first time that NaGdF4:Yb,Er/NaGdF4 upconversion-nanocrystal-based multifunctional nanomaterials have been synthesized and applied in PDT. Our results show that these multifunctional nanoparticles are very promising for applications in versatile imaging diagnosis and as a therapy tool in biomedical engineering.NSFC 21101131 21021061 20925103 20871100 Fok Ying Tung Education Foundation 121011 NSF of Fujian Province 2009J06005 Fundamental Research Funds for the Central Universities 2010121015 Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry NFFTBS J103041