Cell structure imaging with bright and homogeneous nanometric light source.

Label-free optical nano-imaging of dendritic structures and intracellular granules in biological cells is demonstrated using a bright and homogeneous nanometric light source. The optical nanometric light source is excited using a focused electron beam. A zinc oxide (ZnO) luminescent thin film was fabricated by atomic layer deposition (ALD) to produce the nanoscale light source. The ZnO film formed by ALD emitted the bright, homogeneous light, unlike that deposited by another method. The dendritic structures of label-free macrophage receptor with collagenous structure-expressing CHO cells were clearly visualized below the diffraction limit. The inner fiber structure was observed with 120 nm spatial resolution. Because the bright homogeneous emission from the ZnO film suppresses the background noise, the signal-to-noise ratio (SNR) for the imaging results was greater than 10. The ALD method helps achieve an electron beam excitation assisted microscope with high spatial resolution and high SNR.

Label-free cellular structure imaging with 82 nm lateral resolution using an electron-beam excitation-assisted optical microscope.

We present label-free and high spatial-resolution imaging for specific cellular structures using an electron-beam excitation-assisted optical microscope (EXA microscope). Images of the actin filament and mitochondria of stained HeLa cells, obtained by fluorescence and EXA microscopy, were compared to identify cellular structures. Based on these results, we demonstrated the feasibility of identifying label-free cellular structures at a spatial resolution of 82 nm. Using numerical analysis, we calculated the imaging depth region and determined the spot size of a cathodoluminescent (CL) light source to be 83 nm at the membrane surface.

Intensity distribution analysis of cathodoluminescence using the energy loss distribution of electrons.

We present an intensity distribution analysis of cathodoluminescence (CL) excited with a focused electron beam in a luminescent thin film. The energy loss distribution is applied to the developed analysis method in order to determine the arrangement of the dipole locations along the path of the electron traveling in the film. Propagating light emitted from each dipole is analyzed with the finite-difference time-domain (FDTD) method. CL distribution near the film surface is evaluated as a nanometric light source. It is found that a light source with 30 nm widths is generated in the film by the focused electron beam. We also discuss the accuracy of the developed analysis method by comparison with experimental results. The analysis results are brought into good agreement with the experimental results by introducing the energy loss distribution.

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope.

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

Fabrication of bright and thin Zn2SiO4 luminescent film for electron beam excitation-assisted optical microscope.

We fabricated a bright and thin Zn2SiO4 luminescent film to serve as a nanometric light source for high-spatial-resolution optical microscopy based on electron beam excitation. The Zn2SiO4 luminescent thin film was fabricated by annealing a ZnO film on a Si3N4 substrate at 1000 °C in N2. The annealed film emitted bright cathodoluminescence compared with the as-deposited film. The film is promising for nano-imaging with electron beam excitation-assisted optical microscopy. We evaluated the spatial resolution of a microscope developed using this Zn2SiO4 luminescent thin film. This is the first report of the investigation and application of ZnO/Si3N4 annealed at a high temperature (1000 °C). The fabricated Zn2SiO4 film is expected to enable high-frame-rate dynamic observation with ultra-high resolution using our electron beam excitation-assisted optical microscopy.

Economic evaluation of adjustments of levofloxacin dosage by dispensing pharmacists for patients with renal dysfunction.

Since April 2011, a dosage adjustment program has been implemented at Gifu Municipal Hospital. In this program, upon receiving a prescription for renally eliminated drugs, pharmacists verify patients' serum creatinine concentrations by using a computerized medical record system to evaluate the patient's kidney function and suggest the appropriate dosage to doctors, if necessary. In our study, we used questionnaires that were administered to pharmacists and doctors at the hospital to investigate their respective working times and the cost of the program, in order to comprehensively analyze the clinical resource costs of the hospital and evaluate the economic burden of the program for levofloxacin. In addition, we studied the pharmacists' and doctors' attitudes toward the program and the circumstances of prescriptions for patients with renal dysfunction. The questionnaire comprised items such as time required for the program; attitude toward the program, including satisfaction; and attitude toward the circumstances of prescriptions for patients with renal dysfunction. The pharmacists' and doctors' working times and cost of the program were obtained from the questionnaire responses. For cost estimation, we used data from this study as well as those of our previous study that suggested that the levofloxacin program was economically beneficial. Furthermore, their attitudes toward the program and circumstances of prescriptions for patients with renal dysfunction were clarified. Regarding the pharmacists' tasks and interventions, we need to not only investigate attitudes toward them but also perform a cost analysis by the method of the economic evaluation of the medical techniques used in our study.