An Anonymous System Based on Random Virtual Proxy Mutation

Anonymous systems are usually used to protect users\u27 privacy in network communication. However, even in the low-latency Tor system, it is accompanied by network communication performance degradation, which makes users have to give up using the anonymity system in many applications. Therefore, we propose a novel anonymity system with rotated multi-path accompanying virtual proxy mutation for data transmission. Unlike onion routing, in our system the randomly generated virtual proxies take over the address isolation executing directly on the network layer and expand the anonymity space to all terminals in the network. With the optimal algorithm of selecting the path, the network communication performance improved significantly also. The verification experiments show that the anonymity system terminal sends and receives data at 500 kbps, and only a slight delay jitter occurs at the receiving end, and the other network performance is not significantly reduced

Amphiphilic-Polymer-Guided Plasmonic Assemblies and Their Biomedical Applications

Plasmonic nanostructures with unique physical and biological properties have attracted increased attention for potential biomedical applications. Polymers grafted on metal nanoparticle surface can be used as assembly regulating molecules to guide nanoparticles organize into ordered or hierarchical structures in solution, within condensed phases, or at interfaces. In this Topical Review, we will highlight recent efforts on self-assembly of gold nanoparticles coated with polymer brushes. How and what kind of polymer graft can be used to adjust nanoparticle interactions, to dictate interparticle orientation, and to determine assembled nanostructures will be discussed. Furthermore, the Topical Review will shed light on the physicochemical properties, including self-assembly behavior and kinetics, tunable localized surface plasmon resonance effect, enhanced surface enhanced Raman scattering, and other optical and thermal properties. The potential of self-assembled nanostructures for applications in different fields, especially in biomedicine, will also be elaborated

Generalized Dechirp-Keystone Transform for Radar High-Speed Maneuvering Target Detection and Localization

The multivariate range function of the high-speed maneuvering target induces modulations on both the envelop and phase, i.e., the range cell migration (RCM) and Doppler frequency migration (DFM) which degrade the long-time coherent integration used for detection and localization. To solve this problem, many long-time coherent integration methods have been proposed. Based on mechanisms of typical methods, this paper names two signal processing modes, i.e., processing unification (PU) mode and processing separation (PS) mode, and presents their general forms. Thereafter, based on the principle of the PS mode, a novel long-time coherent integration method, known as the generalized dechirp-keystone transform (GDKT), is proposed for radar high-speed maneuvering target detection and localization. The computational cost, energy integration, peak-to-sidelobe level (PSL), resolution, and anti-noise performance of the GDKT are analyzed and compared with those of the maximum likelihood estimation (MLE) method and keystone transform-dechirp (KTD) method. With mathematical analyses and numerical simulations, we validate two main superiorities of the GDKT, including (1) the statistically optimal anti-noise performance, and (2) the low computational cost. The real radar data is also used to validate the GDKT. It is worthwhile noting that, based on closed analytical formulae of the MLE method, KTD method, and GDKT, several doubts in radar high-speed maneuvering target detection and localization are mathematically interpreted, such as the blind speed sidelobe (BSSL) and the relationship between the PU and PS modes

Mapping Sentinel Lymph Node Metastasis by Dual-probe Optical Imaging

Purpose: Sentinel lymph node biopsy (SLNB) has emerged as the preferred standard procedure in patients with breast cancer, melanoma and other types of cancer. Herein, we developed a method to intra-operatively map SLNs and differentiate tumor metastases within SLNs at the same time, with the aim to provide more accurate and real-time intraoperative guidance. Experimental Design: Hyaluronic acid (HA), a ligand of lymphatic vessel endothelial hyaluronan receptor (LYVE)-1, is employed as a SLN mapping agent after being conjugated with a near-infrared fluorophore (Cy5.5). Different sized HAs (5, 10 and 20K) were tested in normal mice and mice with localized inflammation to optimize LN retention time and signal to background ratio. Cetuximab, an antibody against epidermal growth factor receptor (EGFR), and trastuzumab, an antibody against human epidermal growth factor receptor 2 (HER2), were labeled with near-infrared fluorophore (IRDye800) for detecting metastatic tumors. LN metastasis model was developed by hock injection of firefly luciferase engineered human head neck squamous carcinoma cancer UM-SCC-22B cells or human ovarian cancer SKOV-3 cells. The metastases within LNs were confirmed by bioluminescence imaging (BLI). IRDye800-Antibodies were intravenously administered 24 h before local administration of Cy5.5-HA. Optical imaging was then performed to identify nodal metastases. Results: Binding of HA with LYVE-1 was confirmed by ELISA and fluorescence staining. HA with a size of 10K was chosen based on the favorable migration and retention profile. After sequential administration of IRDye800-antibodies intravenously and Cy5.5-HA locally to a mouse model with LN metastases and fluorescence optical imaging, partially metastasized LNs were successfully distinguished from un-metastasized LNs and fully tumor occupied LNs, based on the different signal patterns. Conclusions: Fluorophore conjugated HA is a potential lymphatic mapping agent for SLNB. Dual-tracer imaging with the combination of lymphatic mapping agents and tumor targeting agents can identify tumor metastases within SLNs, thus may provide accurate and real-time intra-operative guidance to spare the time spent waiting for a biopsy result

Sequential Drug Release and Enhanced Photothermal and Photoacoustic Effect of Hybrid Reduced Graphene Oxide-Loaded Ultrasmall Gold Nanorod Vesicles for Cancer Therapy

We report a hybrid reduced graphene oxide (rGO)-loaded ultrasmall plasmonic gold nanorod vesicle (rGO-AuNRVe) (∼65 nm in size) with remarkably amplified photoacoustic (PA) performance and photothermal effects. The hybrid vesicle also exhibits a high loading capacity of doxorubicin (DOX), as both the cavity of the vesicle and the large surface area of the encapsulated rGO can be used for loading DOX, making it an excellent drug carrier. The loaded DOX is released sequentially: near-infrared photothermal heating induces DOX release from the vesicular cavity, and an intracellular acidic environment induces DOX release from the rGO surface. Positron emission tomography imaging showed high passive U87MG tumor accumulation of ⁶⁴Cu-labeled rGO-AuNRVes (∼9.7% ID/g at 24 h postinjection) and strong PA signal in the tumor region. Single intravenous injection of rGO-AuNRVe-DOX followed by low-power-density 808 nm laser irradiation (0.25 W/cm²) revealed effective inhibition of tumor growth due to the combination of chemo- and photothermal therapies. The rGO-AuNRVe-DOX capable of sequential DOX release by laser light and acid environment may have the potential for clinical translation to treat cancer patients with tumors accessible by light

Activatable Singlet Oxygen Generation from Lipid Hydroperoxide Nanoparticles for Cancer Therapy

Reactive oxygen species (ROS) induced apoptosis is a widely practiced strategy for cancer therapy. Although photodynamic therapy (PDT) takes advantages of spatial-temporal control of ROS generation, the meticulous participation of light, photosensitizer, and oxygen greatly hinders the broad application of PDT as a first-line cancer treatment option. Here, we developed an activatable system enabling tumor-specific singlet oxygen ( 1 O 2 ) generation for cancer therapy, based on a Fenton-like reaction between linoleic acid hydroperoxide (LAHP) tethered on iron oxide nanoparticles (IO NPs) and the released iron(II) ions from IO NPs under acidic-pH condition. We show that the IO-LAHP NPs are able to induce efficient apoptotic cancer cell death both in vitro and in vivo through tumor-specific 1 O 2 generation and subsequent ROS mediated mechanism. This study demonstrates the effectiveness of modulating biochemical reactions as a ROS source to exert cancer death, which may pave the way to develop novel strategies for cancer therapy. Singlet oxygen generation through an activatable biochemical reaction between lipid hydroperoxide and catalytic iron(II) ions from iron oxide nanoparticles was engineered as a novel cancer therapy strategy, which showed promise to exert apoptotic cancer cell death both in vitro and in vivo