Real-time ultrafast oscilloscope with a relativistic electron bunch train.

The deflection of charged particles is an intuitive way to visualize an electromagnetic oscillation of coherent light. Here, we present a real-time ultrafast oscilloscope for time-frozen visualization of a terahertz (THz) optical wave by probing light-driven motion of relativistic electrons. We found the unique condition of subwavelength metal slit waveguide for preserving the distortion-free optical waveform during its propagation.

Method for developing a sub-10 fs ultrafast electron diffraction technology.

The experimental observation of femtosecond dynamics in atoms and molecules by stroboscopic technologies utilizing x ray or electron flashes has attracted much attention and has rapidly developed. We propose a feasible ultrafast electron diffraction (UED) technology with high brightness and a sub-10 fs temporal resolution. We previously demonstrated a UED system with an overall temporal resolution of 31 fs by using an RF photoelectron gun and a 90° achromatic bending structure.

One-step synthesis of gene carrier via gamma irradiation and its application in tumor gene therapy.

Introduction: Although numerous studies have been conducted with the aim of developing drug-delivery systems, chemically synthesized gene carriers have shown limited applications in the biomedical fields due to several problems, such as low-grafting yields, undesirable reactions, difficulties in controlling the reactions, and high-cost production owing to multi-step manufacturing processes.

Materials And Methods: We developed a 1-step synthesis process to produce 2-aminoethyl methacrylate-grafted water-soluble chitosan (AEMA-g-WSC) as a gene carrier, using gamma irradiation for simultaneous synthesis and sterilization, but no catalysts or photoinitiators. We analyzed the AEMA graft site on WSC using 2-dimensional nuclear magnetic resonance spectroscopy (2D NMR; 1H and 13C NMR), and assayed gene transfection effects in vitro and in vivo.

Evaluation of polyethylene glycol-conjugated novel polymeric anti-tumor drug for cancer therapy.

A novel polymeric prodrug (PXPEG) was prepared to enhance the solubility of an anti-cancer drug, paclitaxel, in aqueous solutions and decrease the cytotoxicity by PEGylation, which means PEG attached to another molecule. In addition, the targeting ligand, transferrin (TF), was modified to PXPEG to enhance the therapeutic efficacy. The targeting ligand-modified PXPEG (TFPXPEG) was examined by (1)H-NMR to confirm the successful synthesis.