Theranostic Agent Combining Fullerene Nanocrystals and Gold Nanoparticles for Photoacoustic Imaging and Photothermal Therapy

Developing photoactivatable theranostic platforms with integrated functionalities of biocompatibility, targeting, imaging contrast, and therapy is a promising approach for cancer diagnosis and therapy. Here, we report a theranostic agent based on a hybrid nanoparticle comprising fullerene nanocrystals and gold nanoparticles (FGNPs) for photoacoustic imaging and photothermal therapy. Compared to gold nanoparticles and fullerene crystals, FGNPs exhibited stronger photoacoustic signals and photothermal heating characteristics by irradiating light with an optimal wavelength. Our studies demonstrated that FGNPs could kill cancer cells due to their photothermal heating characteristics in vitro. Moreover, FGNPs that are accumulated in tumor tissue via the enhanced permeation and retention effect can visualize tumor tissue due to their photoacoustic signal in tumor xenograft model mice. The theranostic agent with FGNPs shows promise for cancer therapy.     

Connection structures between type-I and type-II defects in neutron irradiated beta-Si3N4

High-resolution electron microscopy (HREM) observation clarified that various types of interstitial dislocations were induced into beta-Si3N4 by high-dose neutron irradiation, and two of them have been analysed and reported in our previous papers. These two defective structures are called type-I and type-II. They are interstitial dislocation loops introduced into [100] and [110] planes, respectively. In this study, it was found that some of these dislocation loops connected with each other. The connections of type-I-L2-type-II-B and type-I-R2-type-II-A dislocations were observed by HREM. Tetrahedral arrangements of the connected parts are proposed, based on the simplified crystal structure model of beta-Si3N4. In addition, a new type of defect, type-III, was found. Type-III is an interstitial dislocation loop introduced into [100] planes. It was also found that type-I-A and type-III dislocations connected with each other.     

Block-Orthogonal Frequency Division Multiplexing in Multi-Path Fading Channel

Orthogonal frequency division multiplexing (OFDM) is robust against multi-path interference due to using a lot of low symbol rate sub-carriers. In order to mitigate the degradation due to multi-path interference, guard time interval (GI) is inserted into each OFDM symbol. However, redundant allocation to GI leads to loss of effective transmission power. We propose the Block-OFDM which can reduce the GI overhead ratio per frame compared with conventional OFDM. In Block-OFDM system frequency domain equalization (FDE) is carried out in order to remove multi-path interference. We evaluated Block-OFDM performance in a frequency selective fading channel and compared with that of conventional OFDM. Ryohei Kimura received his B.E. and M.S degrees in communications engineering form Tohoku University, Sendai, Japan, in 2001 and 2003, respectively. In 2003, he joined Panasonic Mobile Communications Co., Ltd. His current research interests include such mobile communication technologies as OFDM and MIMO (MLD), and the like. Akiyoshi Monma received his B.E. in communications engineering form Tohoku University, Sendai, Japan, in 1998. In 1998, he joined Panasonic Mobile Communications Sendai R&D Lab. Co., Ltd. His current research interests include such mobile communication technologies as OFDM and PAPR reduction, and the like. Jinsong Duan received his B.E. and M.S. from Changsha Institute of Technology, China in 1987 and 1990. He received his Ph.D. from Osaka City University, Japan in 2000. From 2000–2003 he was with Mitsubishi Electric Corporation, where he engaged in research and development of WCDMA systems. From 2003, he joined Panasonic Mobile Communications Co., Ltd. His current interests include such mobile communication technologies as OFDM, MIMO, link adaptation, scheduling, and TDMA/FDMA/CDMA systems. Mitsuru Uesugi received his B.E. degree from Waseda University in 1986 and received his Ph.D degree from Tohoku University in 2004, respectively. He is a general manager in the Mobile Communication Technology Development Center of Panasonic Mobile Communications Co., Ltd. His current research interests include such mobile communication technologies as equalization, interference cancellation, modulation method, and the like.     

Device design with automatic simulation system for basic CCDcharacteristics

A simulation system has been developed to automatically analyze basic electrical characteristics of a charge-coupled device (CCD) image sensor from a process simulation result. This system shortened the simulation period to approximately 1/10 by getting rid of complicated repetitious procedures. A high-performance new cell technology has been developed successfully with improving impurity distribution in shorter development time by using this system. This technology has been realized as a CCD cell pixel with CCD charge quantity of 1.8 times, effective transfer efficiency of over 99%, no image lag for driving read-out pulse voltage in comparison with conventional technology. A 1/4-in 330 K square pixel progressive-scan CCD was fabricated with this technology. These results are described to demonstrate the effectiveness of the automatic simulation system     

Extraction of a plasma time-activity curve from dynamic brain PET images based on independent component analysis

A compartment model has been used for kinetic analysis of dynamic positron emission tomography (PET) data [e.g., 2-deoxy-2-18F-fluoro-D-glucose (FDG)]. The input function of the model [the plasma time-activity curve (pTAC)] was obtained by serial arterial blood sampling. It is of clinical interest to develop a method for PET studies that estimates the pTAC without needing serial arterial blood sampling. For this purpose, we propose a new method to extract the pTAC from the dynamic brain PET images using a modified independent component analysis [extraction of the pTAC using independent component analysis (EPICA). Source codes of EPICA are freely available at http://www5f.biglobe.ne.jp/?kimura/Software/top.html]. EPICA performs the appropriate preprocessing and independent component analysis (ICA) using an objective function that takes the various properties of the pTAC into account. After validation of EPICA by computer simulation, EPICA was applied to human brain FDG-PET studies. The results imply that the EPICA-estimated pTAC was similar to the actual measured pTAC, and that the estimated blood volume image was highly correlated with the blood volume image measured using 15O-CO inhalation. These results demonstrated that EPICA is useful for extracting the pTAC from dynamic PET images without the necessity of serial arterial blood sampling.     

Nitric oxide decomposition in air by using nonthermal plasmaprocessing with additives and catalyst

Catalyst (copper-coated zeolite catalyst, i.e., Cu-ZSM-5) was used to enhance NO_x removal plasma chemical reactions. Two kinds of hydrocarbons (2-propane-1-ol, 2-propanol) were added to the synthesized flue gas before the nonthermal plasma process, and their effects on NO_x removal characteristics were investigated. Enhancement effects of NO_x removal by the nonthermal plasma process with hydrocarbons as the additives were confirmed. Usually, the catalyst's working temperature is much higher than the room temperature. A catalytic reactor was installed after the plasma reactor. Catalytic effects on NO_x removal characteristics disappeared when the synthesized flue gas temperature was increased (~250°C). When the synthesized flue gas temperature was at room temperature, about 90% NO _x removal efficiency was realized with a combination of hydrocarbons, the catalytic reactor, and the pulsed discharge plasma     

New low-noise output amplifier for high-definition CCD image sensor

A new low-noise charge-coupled-device (CCD) output amplifier, the RJG detector, has been developed. The RJG detector incorporates a JFET which has an electrically floating ring-junction gate (RJG). The operating principle of the amplifier is that signal charges, transferred from the CCD into the RJG, directly modulate the drain current in the detection JFET. The performance of the detector was evaluated by operating test devices under a 37-MHz clock frequency, which is the same frequency as that for the horizontal CCD operation in the recently developed 2-million-pixel high-definition CCD image sensor. It was found that 1/f noise was reduced by introducing the JFET and that reset noise was completely eliminated by achieving complete charge transfer through the reset operation. As a result, input referred noise equivalent electrons within the 18.5-MHz baseband were reduced to 17 (electrons)     

Effects of bile acid feeding on hepatic deoxycholate 7α-hydroxylase activity in the hamster

In order to investigate the effects of bile acid feeding on hepatic microsomal deoxycholate 7α-hydroxylase activity, three different bile acids were administered (0.2% w/w in chow) to hamsters for two weeks. Deoxycholate 7α-hydroxylase activity was increased markedly by feeding of cholic acid (CA) and slightly by deoxycholic acid (DCA) Chenodeoxycholic acid (CDCA) had little effect on the enzyme activity. Feeding each of the bile acids significantly inhibited the activity of cholesterol 7α-hydroxylase in the order CDCA≥ DCA>CA. There was no correlation between deoxycholate 7α-hydroxylase activity and cholesterol 7α-hydroxylase activity. It is concluded that the activity of deoxycholate 7α-hydroxylase is up-regulated by feeding DCA and CA and that the mechanism seems to be different from that of cholesterol 7α-hydroxylase. The increased activity of hepatic deoxycholate 7α-hydroxylase by CA and DCA should be beneficial in minimizing the toxic effects of DCA in the hamster.     

Multichannel frequency conversion experiment using fibre four-wave mixing

Multichannel frequency conversion is demonstrated using four-wave mixing. A polarisation independent configuration is employed, by which polarisation control for each signal is not necessary. By setting the pump light frequency at the zero-dispersion wavelength of the fibre, three FSK modulated signals with a frequency spacing of 70 GHz are simultaneously converted with an equal efficiency of -27.5 dB. Bit error rate measurements confirm the feasibility of this conversion scheme.<>     

Measurement of RF Transmission Mode in ITER Relevant EC H&;CD Transmission Line

The preliminary results of mode measurement in the ITER relevant 40 m long transmission test line composed from 63.5 mm diameter corrugated waveguides and miter bends are presented. The field patterns were measured by taking temperature profiles on a paper screen placed in front of the waveguide end using an infrared imaging camera. The complex electric field at the waveguide end was retrieved from the measured temperature profiles. As a result, the transmission power includes 87% of HE₁₁ mode and 6% of LP₁₁ odd (HE₂₁+TE₀₁) mode and small ratios of other modes. The mode content had small dependence on length of the transmission line. This result indicated that the higher order mode content generated at the input of the transmission line is conserved and propagated through the transmission line. This suggests that the initial RF coupling to the waveguide is critical since it affects the launcher efficiency.