Thoracoscopic treatment of bronchogenic cyst

A central bronchogenic cyst was excised thoracoscopically from a 44-year-old woman in whom a tumor had been pointed out in the left upper posterior mediastinum at a screening examination. Since the tumor was diagnosed to be benign, only conservative follow-up was undertaken, but the patient consulted our department desiring active therapy. On the basis of the chest CT and MRI findings a bronchogenic cyst was diagnosed. Under general anesthesia and mechanical ventilation of one lung, the thoracoscope was inserted into the thoracic cavity revealing in the left upper posterior mediastinum a cyst which was excised thoracoscopically. While coagulation was performed gingerly with an electric scalpel, the tumor was detached sharply and bluntly with a pair of scissors. The postoperative course was uneventful with little wound pain or scar formation. Hitherto bronchogenic cysts have been treated by resection after thoracotomy. Although this is an easy procedure, a relatively large operative scar is left and considerable wound pain may develop. In contrast, thoracoscopic treatment is characterized by minimal surgical invasiveness, little postoperative wound pain, and small scars. These advantages suggest that this technique may be indicated for benign mediastinal tumors, particularly cysts.     

Experimental transmission of hantavirus infection in laboratory rats

This study found a competent transmission of hantavirus between cagemates using congenitally T cell-deficient Rowett nude rats (rnu/rnu). Intraperitoneally infected immunologically normal rats (rnu/+) did not transmit the hantavirus to their normal cagemates (rnu/+) but did to Rowett nude rats (rnu/rnu). Thus, nude rats were shown to be highly susceptible to the hantavirus infection. Also, infected nude rats (rnu/rnu) discharged the infectious viruses, to cause a prevalence of infection among normal cagemates (rnu/+). The infection system demonstrated here using Rowett rats (rnu/rnu) may provide a useful model to study the mechanism of the hantavirus infection.     

Functional competence of T cells in the absence of glycosylphosphatidylinositol-anchored proteins caused by T cell-specific disruption of the Pig-a gene

T lymphocytes express various glycosylphosphatidylinositol (GPI)-anchored surface proteins, such as Thy-1 and Ly-6A. However, functional contribution of GPI-anchored proteins in T cell activation is as yet poorly understood. Here we report the generation of mutant mice deficient in the expression of GPI-anchored molecules exclusively in their T cells. We established mice carrying three identically oriented lox-P sites within the Pig-a gene, which encodes a component essential for the initial step of GPI anchor biosynthesis. These mice were crossed with mice carrying the Cre recombinase gene driven by the T cell-specific p56lck proximal promoter. Offspring carrying both the lox-P-containing Pig-a gene and the Cre transgene exhibited almost complete loss of the surface expression of GPI-anchored molecules on peripheral T cells. Interestingly, those T cells deficient in GPI-anchored molecules were capable of responding to T cell receptor stimulation in vitro and in vivo. These results indicate that T cells lacking the expression of GPI-anchored molecules are functionally competent in exerting TCR-mediated immune responses.     

An Optical Parametric Amplified Fiber Switch for Optical Signal Processing and Regeneration

An optical parametric amplified (OPA) fiber switch is described in this paper. This device switches input signals without shifting the wavelength by changing the polarization state of the signal using optical parametric amplification. The OPA fiber switch features ultra-broadband, highly efficient switching with a high contrast ratio. We experimentally test the prototype of the OPA fiber switch, which uses a highly nonlinear fiber. Optical demultiplexing of 160 Gb/s differential phase-shift keying (DPSK) signals is demonstrated in the whole C-band and shows that it provides almost penalty-free optical detection. The application of amplitude noise suppression with the OPA fiber switch by using parametric gain saturation is then proposed and demonstrated for a 160 Gb/s DPSK signal. When it is set to an amplitude-limiting condition, the OPA fiber switch successfully increases the optical signal-to-noise ratio by 4 dB and effectively suppresses the phase deterioration in 160 Gb/s DPSK transmission by increasing the system margin by more than 5 dB.     

Real-Time Amplitude and Phase Imaging of Optically Opaque Objects by Combining Full-Field Off-Axis Terahertz Digital Holography with Angular Spectrum Reconstruction

Terahertz digital holography (THz-DH) has the potential to be used for non-destructive inspection of visibly opaque soft materials due to its good immunity to optical scattering and absorption. Although previous research on full-field off-axis THz-DH has usually been performed using Fresnel diffraction reconstruction, its minimum reconstruction distance occasionally prevents a sample from being placed near a THz imager to increase the signal-to-noise ratio in the hologram. In this article, we apply the angular spectrum method (ASM) for wavefront reconstruction in full-filed off-axis THz-DH because ASM is more accurate at short reconstruction distances. We demonstrate real-time phase imaging of a visibly opaque plastic sample with a phase resolution power of λ/49 at a frame rate of 3.5 Hz in addition to real-time amplitude imaging. We also perform digital focusing of the amplitude image for the same object with a depth selectivity of 447 μm. Furthermore, 3D imaging of visibly opaque silicon objects was achieved with a depth precision of 1.7 μm. The demonstrated results indicate the high potential of the proposed method for in-line or in-process non-destructive inspection of soft materials.     

The current state of tribology in Japan

Aspects of the current state of tribology in Japan are reviewed. The marked activity of the Tribology Society, international relations, tribology in industry and tribology education are described and several topical research areas are highlighted. The greatest change in the last 25 years is that individual tribologists have begun to share their own information rather than to simply accept that of others, not only within Japan but also internationally.     

Electromagnetic Shielding Properties of Woodceramics Made from Wastepaper

Woodceramics are new porous carbon materials, which are made by impregnating woody materials with phenol resin and then thermoformed in a vacuum furnace and these have been shown to have electromagnetic shielding properties. In the recycling of wastepaper, ways of using the wastepaper other than for paper pulp are needed to be developed. In this study, we made Woodceramics from handbill advertisement paper and telephone directory paper, and measured their electromagnetic shielding properties in order to find new uses for wastepaper. The results showed that the Woodceramics made from wastepaper had an electric shielding effectiveness of 30 dB for 100 MHz and 40 to 43 dB for 300 MHz or higher, and had a magnetic shielding effectiveness of 30 dB for 100 MHz and 37 dB for about 400 MHz. An electric equivalent circuit of the pore model in the Woodceramics is introduced. In addition, it is proposed that the excellent electromagnetic shielding effectiveness of the Woodceramics is caused by dielectric loss.     

Spatio-temporal growth of broken spiral and concentric ringed spherulites in blends of poly(vinylidene fluoride) and ethylene-vinylacetate copolymers

Melting and crystallization behavior in mixtures of poly(vinylidene fluoride) (PVDF) and several ethylene-vinyl acetate copolymers (EVAc) with various ethylene contents have been investigated by means of differential scanning calorimetry, atomic force microscope, and optical microscopy. PVDF/EVAc-80 exhibits the melting point depression of PVDF crystals, suggestive of a miscible character of the pair. Crystallization behavior and morphology development in blends of PVDF/EVAc-80 have been investigated with an emphasis on the spherulitic growth demonstrating the spiral and concentric ringed (or target) patterns. Of particular interest is the break-up of the spiral or concentric ringed patterns at very shallow supercoolings, which may be attributed to instabilities driven by the exclusion of amorphous PVDF and EVAc chains into the emerging inter- and intra-spiral (or target) lamellar regions.     

Evaluation of the impact of bioaugmentation and biostimulation by in situ hybridization and microelectrode

Three rotating disk biofilm reactors were operated to evaluate whether bioaugmentation and biostimulation can be used to improve the start-up of microbial nitrification. The first reactor was bioaugmented during start-up period with an enrichment culture of nitrifying bacteria, the second reactor received a synthetic medium containing NH(4)(+) and NO(2)(-) to facilitate concomitant proliferation of ammonia- and nitrite-oxidizing bacteria, and the third reactor was used as a control. To evaluate the effectiveness of bioaugmentation and biostimulation approaches, time-dependent developments of nitrifying bacterial community and in situ nitrifying activity in biofilms were monitored by fluorescence in situ hybridization (FISH) technique and microelectrode measurements of NH(4)(+), NO(2)(-), NO(3)(-), and O(2). In situ hybridization results revealed that addition of the enrichment culture of nitrifying bacteria significantly facilitated development of dense nitrifying bacterial populations in the biofilm shortly after, which led to a rapid start-up and enhancement of in situ nitrification activity. The inoculated bacteria could proliferate and/or survive in the biofilm. In addition, the addition of nitrifying bacteria increased the abundance of nitrifying bacteria in the surface of the biofilm, resulting in the higher nitrification rate. On the other hand, the addition of 2.1mM NO(2)(-) did not stimulate the growth of nitrite-oxidizing bacteria and did inhibit the proliferation of ammonia-oxidizing bacteria instead. Thus, the start-up of NO(2)(-) oxidation was unchanged, and the start-up of NH(4)(+) oxidation was delayed. In all the three biofilm reactors, data sets of time series analyses on population dynamics of nitrifying bacteria determined by FISH, in situ nitrifying activities determined by microelectrode measurements, and the reactor performances revealed an approximate agreement between the appearance of nitrifying bacteria and the initiation of nitrification activity, suggesting that the combination of these techniques was a very powerful monitoring tool to evaluate the effectiveness of bioaugmentation and biostimulation strategies.     

Determination of potent antisense oligonucleotides in vitro by semiempirical rules

The selection of effective antisense target sites on a given mRNA molecule is a major problem in the detection of target mRNA in oligonucleotide arrays. In general, antisense oligodeoxynucleotides (asODNs) of about 10-20 nucleotides (nt) in length are used. However, the demand for predicting the sequence of potent asODNs much longer than those mentioned above has been increasing. Here, we prepared 40-nt asODNs directed against fluorescence-labeled green fluorescent protein (GFP) mRNA and quantified their hybridization efficiencies by fluorescence microscopy. We found that the hybridization efficiency depended on the TC content or the minimum free energy of the asODNs. On the basis of these findings, a semiempirical parameter called accessibility score was introduced to predict the potency of asODNs. The results of this study aided in the development of an effective two-step procedure for determining mRNA accessibility, namely, the computer-aided selection of asODN binding sites using an accessibility score followed by an experimental procedure for measuring the hybridization efficiencies between the selected asODNs and the target mRNA by fluorescence microscopy.