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The authors propose a new grid voltage control scheme to determine the optimal sending voltage profile so as to minimize total number of tap position changes per day under constraints of acceptable voltage limit for distribution feeders with photovoltaic systems (PVs). In order to verify the validity of the proposed grid voltage control scheme for multiple PV connections, numerical examples for a grid model with PV were shown.

We previously developed two new MRI phantoms (called the CAG phantom and the CAGN phantom), with T1 and T2 relaxation times equivalent to those of any human tissue at 1.5 T. The conductivity of the CAGN phantom is equivalent to that of most types of human tissue in the frequency range of 1 to 130 MHz. In this paper, the relaxation times of human tissues are summarized, and the composition of the corresponding phantoms are provided in table form. The ingredients of these phantoms are carrageenan as the gelling agent, GdCl3 as a T1 modifier, agarose as a T2 modifier, NaCl (CAGN phantom only) as a conductivity modifier, NaN3 as an antiseptic, and distilled water. The phantoms have T1 values of 202-1904 ms and T2 values of 38-423 ms when the concentrations of GdCl3 and agarose are varied from 0-140 micromol/kg, and 0%-1.6%, respectively, and the CAGN phantom has a conductivity of 0.27-1.26 S/m when the NaCl concentration is varied from 0%-0.7%. These phantoms have sufficient strength to replicate a torso without the use of reinforcing agents, and can be cut by a knife into any shape. We anticipate the CAGN phantom to be highly useful and practical for MRI and hyperthermia-related research.

We developed a new hybrid gel phantom using carrageenan and gellan gum for the purpose of visualizing three-dimensional temperature distribution. The phantom, which contains carrageenan, gellan gum, non-ionic surface active agent, potassium chloride, n-butanol, sodium azide, and water, shows good transparency at room temperature, and has the advantage that the heated region becomes white and opaque due to segregation of the surface active agent. Carrageenan and gellan gum were added to improve the transparency and fragility of the hybrid gel. Potassium chloride was used to adjust the electrical conductivity of the gel to a range of 5-130 MHz, so that it would be equivalent to that of muscle tissue for each frequency used by electromagnetic heating devices. N-butanol was used to adjust the clouding temperature to a range between 45 and 55 degrees C. In the present study we clarified the important properties of the new phantom, and developed formulae for easy determination of the amounts of ingredients necessary for the desired clouding temperature and electric conductivity. The characteristics of this phantom are: a) a solid form to avoid convection by heat conduction; b) sufficient strength without fragility to form a torso without the use of a reinforcing agent; c) high transparency at room temperature and visualization of the heating area as a white turbidity; d) time-lapse and accurate visualization of the changing temperature area without thermal hysteresis; e) electrical properties similar to those of human tissues; f) ease of production; and g) low cost and good safety. This phantom might assist oncologists in their routine checking and study of the performance of electromagnetic heating devices for hyperthermia and radiofrequency ablation.

We previously developed a new microscopic observation system that enables time-lapse quantitative analysis of apoptosis and necrosis. With this system we quantitatively analyzed adriamycin (ADR)-induced cell death using manganese superoxide dismutase (MnSOD)- and wild-type p53-gene transfectants on SaOS 2 , a p53-deficient human osteosarcoma cell line. A highly MnSOD-overexpressing cell line, SaOS 2 FM(H), acquired ADR-tolerance compared to the parent cell line SaOS 2 . The ADR-tolerance of SaOS 2 FM(H) diminished by L-buthionine-[S,R]-sulfoximine (BSO), which did not change ADR-sensitivity of SaOS 2 , to the similar ADR-sensitivity of SaOS 2 . A wild-type p53-expressing cell line, SaOS 2 wtp53, significantly increased in ADR-sensitivity compared to SaOS 2 . This ADR-sensitivity of SaOS 2 wtp53 was enhanced by BSO. When isosorbide 5-mono-nitrate was combined with BSO, isosorbide 5-mononitrate increased ADR sensitivity of a moderately MnSOD-over-expressing cell line, SaOS 2 FM(L), decreased that of SaOS 2 FM(H), and did not change those of SaOS 2 and SaOS 2 wtp53 compared to BSO alone. Time-lapse microscopic observations during ADR treatment for 24 h indicated that the most cells of each cell line underwent apoptosis, and a few cells (less than 11%) died by necrosis. When cells were treated with iso-concentration of ADR, apoptosis of SaOS 2 FM(H) was less than that of SaOS 2 . BSO, which did not change ADR-sensitivity of SaOS 2 , increased appearance rate of ADR-induced apoptosis, but not necrosis of MnSOD-over-expressing cell lines. When iso-survival dose of ADR, which reduced surviving fraction to 0.01, was given for each cell line, no difference was observed in appearance of either apoptosis or necrosis between SaOS 2 and MnSOD-over-expressing cell lines. On the other hands, appearance of both apoptosis and the following secondary necrosis of SaOS 2 wtp53 was significantly accelerated compared to those of SaOS 2 . These findings indicate that hydrogen peroxide overload on p53-independent pathway due to MnSOD overexpression plus BSO might increase the apoptosis frequency without acceleration of apoptotic process of each cell, resulting in negating ADR-tolerance of MnSOD-over-expressing cell lines.

Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme that converts cytotoxic superoxide radicals into hydrogen peroxide. MnSOD activity is lower in tumor cells, and MnSOD overexpression reportedly ameliorates malignant phenotypes. We established stable MnSOD overexpressing cell lines from a human osteosarcoma cell line, SaOS2, and then investigated the effects of MnSOD overexpression on plating efficiency (PE) and the involvement of reactive oxygen species, including nitric oxide (NO) in those effects. The PE of SaOS2FM(L), a moderate MnSOD overexpression cell line, increased, while that of SaOS2FM(H), a high MnSOD overexpression cell line, decreased. Although we assessed PE using a colony-formation assay, time-lapse microscopic observation revealed that cells attached to the flasks had undergone neither apoptosis nor necrosis. Moreover, MnSOD overexpression did not affect cell doubling time. Therefore, MnSOD overexpression might correlate directly with cellular adhesion's effect on PE changes. When L-buthionine-[S,R]-sulfoximine (BSO) was administered to increase the intracellular concentration of hydrogen peroxide, the PEs of both cell lines decreased, and when hydrogen peroxide was eliminated by the administration of sodium pyruvate, only the PE of SaOS2FM(H) increased. The combination of BSO and NO (NOR4 or isosorbide 5-mononitrate) administration synergistically decreased PE in both cell lines. These findings suggest that changes in cellular adhesion properties correlate with the balance between increased hydrogen peroxide levels and decreased superoxide radical levels. This is the first report to indicate that PE and cellular adhesion properties change bidirectionally according to the levels of MnSOD overexpression: first increasing then decreasing as MnSOD activity increases. Our results indicate that PE changes might be decided by the balance between two cytotoxic compounds (decreased superoxide radical levels and increased hydrogen peroxide levels), and that NO loading and increased hydrogen peroxide synergistically reduce PE and cellular adhesion.

It is known that the O 6 -methylguanine-DNA methyltransferase (MGMT) gene is susceptible to epigenetic regulation associated with an altered frequency of CpG methylation. To investigate whether epigenetic regulation of the MGMT gene might lead to significant reductions in the expression levels of cancer cells, we sought evidence of a link between the methylation status of the MGMT promoter and the expression levels of seven human oral cancer cell lines. We found two frequently methylated regions: the 5' region extending from nt 690 to nt 893 in the promoter, and the more 3' region extending from nt 1060 to nt 1151 in the untranslated first exon. The 3' region was hypermethylated independently of MGMT expression levels in all cell lines. By contrast, in the three MGMT-downregulated cell lines (SAS, Hep2, HO-1-u-1), the levels of MGMT expression were inversely related to the density of 5' region of the methylated CpGs in the MGMT promoter. Our results implied that the transcriptional inactivation of MGMT might require methylation of the 5' region, but not that of the 3' region in oral cancer cell lines. We further explored the role of methylation in MGMT expression by treating cells with 5-Aza-2'-deoxycytidine (5Aza-dC). 5Aza-dC treatment led to the partial or complete cytosine demethylation of two frequently methylated MGMT regions in all cell lines. 5Aza-dC succeeded in upregulating of the MGMT mRNA levels in only 2 of 7 cell lines (HSC3 and HO-1-u-1), and in fact reduced MGMT mRNA in the other 5 cell lines. Furthermore, 5Aza-dC had an inhibitory effect on MGMT protein levels in all cell lines. Our results suggest that MGMT levels may not revert after 5Aza-dC treatment. Based on our findings, the regulation of MGMT expression appears to be more complex than previously thought, although it is at least partially influenced by CpG methylation. Accordingly, care should be taken interpreting the link between MGMT methylation and expression.

We speculated whether or not the expression level of telomerase reverse transcriptase (hTERT) would be modulated by agents targeting epigenetics in oral cancer cell lines. Although hTERT is known to be targeted by epigenetic changes, it remains unclear how chemoagents targeting epigenetics work on hTERT transcription. In the present study, the epigenetic effects of the histone deacetylase (HDAC) inhibitor FR901228 on hTERT transcription in oral cancer cell lines were analyzed by RT-PCR. The mRNA expression of hTERT was upregulated after exposure to FR901228 in hTERT-negative Hep2 cells, and even SAS and KB cells expressed high levels of hTERT. Moreover, cotreatment of protein synthesis inhibitor cycloheximide (CHX) resulted in the induction of hTERT transcription by FR901228. This suggests that the induction of hTERT by FR901228 requires de novo protein synthesis to some extent and is more likely a direct than an indirect effect on epigenetic changes such as histone acetylation/deacetylation. We further examined the effect of FR901228 on c-myc protein, which is one of the main hTERT transcription activators. FR901228 repressed c-myc protein only in the absence of CHX, and depended on the enhancement of de novo protein synthesis. Our results indicate that c-myc protein is repressed indirectly by FR901228 but may not contribute to FR901228-induced hTERT transcription. The present study showed that the HDAC inhibitor FR901228 induced the hTERT gene by a complex mechanism that involved transcription factors other than c-myc, in addition to inhibition of histone deacetylation.

Cepharanthine (Ce) is a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata. In our previous study, Ce significantly enhanced thermosensitivity and thereby reduced thermotolerance in vitro, and intra-peritoneal injection of Ce slightly enhanced thermosensitivity in vivo. In the present study, we investigated Ce's effect in vitro on the pattern of cell death after heating and the effect of intra-tumoral injection of Ce on in vivo thermosensitivity using a mouse fibrosarcoma, FSa-II, and C3H/He mice. Ce significantly enhanced the in vitro thermosensitivity of FSa-II cells with heating at 44 degrees C, with increased Ce concentration. Time-lapse microscopic observation of individual cells confirmed that Ce treatment hastened both apoptosis (specifically, apoptotic budding) and necrosis (as indicated by staining with propidium iodide). Staining with annexin V-enhanced green fluorescent protein indicated that Ce used concomitantly with heating significantly increased the proportion of cells in the early stage of apoptosis. Ce combined with heating also significantly increased the proportion of cells with high intracellular caspase-3 activity, as detected by a substrate of caspase-3, PhiPhiLux-G1D2. The intra-tumoral injection of Ce, followed by heating at 44 degrees C, significantly delayed in vivo tumor growth, and this delay increased in a Ce concentration-dependent manner. Ce injected 30 min before heating delayed tumor growth more than Ce injected immediately before heating. These findings suggest the potential of Ce as a thermosensitizer to increase apoptosis of tumor cells.

Using a pEYFP-Nuc vector, which contains nucleic acid sequences of a nuclear localization signal, we established a Jurkat-YN cell line that expressed enhanced yellow fluorescent protein (EYFP) in the nucleus. We observed three-dimensional and time-lapse changes in nuclear morphology of Jurkat-YN cells during Fas-induced apoptosis using a confocal laser scanning microscope. The nuclear forms visualized by EYFP were almost equal in quality to those visualized by SYTO59, a nucleic acid stain for living cells. Three-dimensional deformities in the nuclear form were observed during apoptosis before chromatin condensation became apparent, indicating these deformities are characteristic morphological changes of the early stage of apoptosis. In conclusion, the pEYFP-Nuc vector is a useful tool in the time-lapse observation of nuclear morphology of living cells during apoptosis.

Maspin, which belongs to the serine protease inhibitor (serpin) superfamily, has been proposed as a potent tumor suppressor that inhibits cell motility, invasion, angiogenesis, and metastasis. In the present study, we examined the effects of 5-aza-2'-deoxycytidine (5-aza-dC), a demethylating agent, and FR901228, a histone deacetylase (HDAC) inhibitor, on maspin expression in oral cancer cell tines. The expression levels of maspin mRNA were divided into two groups, which was the maspin tow-expressed and high-expressed cell lines in the 12 oral cancer cell lines. The maspin promoter contained only a few methylated CpG sites in the maspin low-expressed cell lines. Moreover, the methylation status was not altered after 5-aza-dC treatment. However, the transcription of the maspin gene was clearly increased following 5-aza-dC treatment in a number of oral cancer cell tines. These results imply that an action of 5-aza-dC is separate from induction of promoter demethylation. Treatment with FR901228 resulted in a time-dependent stimulation of the re-expression of maspin mRNA as early as 4 h after treatment in the maspin downregulated cells. The re-expression of the maspin gene may contribute to the recuperation of biological functions linked to FR901228 such as an inhibitory effect on tumor angiogenesis and cell invasion. These results indicate that maspin and its target genes may be excellent leads for future studies on the potential benefits of FR901228, a HDAC inhibitor, in cancer therapy.

We report herein the effects of p53 gene therapy in the radiotherapy or thermotherapy of eight human head and neck squamous cell carcinoma (SCC) cell lines. The discrepancy between radiosensitivity combined with p53 gene therapy than that without p53 gene therapy increased among the eight SCC cell lines. The discrepancy increased in the thermosensitivity at 43 degrees C and decreased in that at 44 degrees C among the eight SCC cell lines. Thus, the p53 gene therapy did not always improve the discrepancy between radiosensitivity and thermosensitivity in the eight SCC cell lines. In the radiotherapy combined with adenoviral p53 gene therapy, the survival rates of three of eight SCC cell lines decreased, and that of only one cell line increased compared with radiotherapy alone. In thermotherapy combined with p53 gene therapy, the survival rates of three at 44 degrees C and five at 43 degrees C of the eight SCC cell lines decreased, although only one cell line at 43 degrees C increased its survival rate compared with thermotherapy alone. The p53 gene therapy decreased the survival rates of both radiotherapy and thermotherapy in three of eight SCC cell lines. Further, the distribution of plots on the basis of the time for 10% survival of radiotherapy and the dose for 10% survival of thermotherapy with p53 gene therapy shifted to the lower left side of the plots compared with those without p53 gene therapy. These findings indicated that p53 gene therapy improves the effects of both radiotherapy and thermotherapy.

We reconstructed the recombinant p53-expressing adenovirus and examined its infections and effects in head and neck squamous cell carcinoma cell lines. Eight human head and neck squamous cell carcinoma cell lines were infected by the recombinant adenovirus harboring the lacZ gene (AxCAiLacZ) or the wild-type p53 gene (AxCAip53), and the effects were investigated. The eight cell lines were successfully infected by AxCAiLacZ at a level of more than 50%. The survival of all 8 squamous cell lines were inhibited in the range from 8 to 26.7% by only one treatment of the AxCAip53 infection. This result suggested that p53 gene therapy might become a useful tool in head and neck squamous cell carcinoma treatment.

Thermoradiosensitivity of 8 cell lines of head and neck squamous cell carcinoma (HO-1-u-1, HSC2, HSC3, HSC4, SAS, KB, Hep2, and Ca9-22) was investigated. The differences of radiosensitivity between the cell line with the highest radiosensitivity and the cell line with the lowest radiosensitivity were 1.7-, 7.7-, and 41-fold at 2, 6 and 8 Gy, respectively. The differences between the cell line with the highest thermosensitivity and the cell line with the lowest thermosensitivity were 2.4-, 6.2- and 34.4-fold at 43 degrees C for 40, 60 and 100 min, and 2.6-, 4.9- and 127-fold at 44 degrees C for 20, 30 and 50 min, respectively. These findings indicated that there were large differences in both radiosensitivity and thermosensitivity among the 8 cell lines. There was a negative relationship between radiosensitivity and thermosensitivity (43 degrees C: r=-0.600, 44 degrees C: r=-0.848) in 7 of 8 cell lines, the exception being the HSC4 cell line, which was resistant to both therapies. Four of the 8 cell lines at 43 degrees C and 5 at 44 degrees C in the radiotherapy combined with thermotherapy showed actual survival rates smaller than the theoretical survival rates. Thus, thermoradiotherapy was deemed effective in the head and neck carcinoma cell lines, although 1 of 8 cell lines was resistant to both radiotherapy and thermotherapy.

The purpose of this study was to examine whether combined cisplatin and late course accelerated fractionation radiotherapy (LCAH) (the combined group) can confer a better outcome over LCAH alone in treating esophageal carcinoma. Eighty-one eligible patients were randomly entered into two groups: the LCAH alone group, and the combined group. There was a better outcome in the combined group compared to the LCAH group, but the difference was not significant. The combined therapy could significantly improve the survival rate and local control of the disease in the early stage, but not in the advanced stage, because of the possibility of invasion. More severe complications occurred in the combined group than in the LCAH group, but they were within tolerance. In conclusion, LCAH concomitant with cisplatin could improve the survival of patients with esophageal cancer, especially in the early stage, as long as the side effects of the treatment are within tolerable limits.

We report on thermochemotherapy in a human salivary gland adenocarcinoma cell line. Hyperthermia reduced the survival rate to 50 and 20% by heating at 43 degrees C for 40 and 60 min, respectively, and is by itself useful in human salivary gland carcinoma treatment. Adriamycin, cisplatin, and mitomycin C can possible be used clinically, while bleomycin and 5-fluorouracil cannot, to treat this carcinoma. The optimal temperature was considered to be 41 degrees C in adriamycin, 42 degrees C in cisplatin, 37 degrees C in mitomycin C, and 42 degrees C in bleomycin in the thermochemotherapy. Thermochemotherapy is a useful tool in the treatment of human salivary gland carcinoma cells, but it is necessary to select the best anticancer drugs and the optimal temperature for optimal success using this treatment.

Formations of a closed flux surface (CFS) on QUEST are achieved by fully non-inductive current start-up driven by RF, which is 8.2GHz in frequency and more than 40kW in power. It found that appropriate magnetic configuration with positive n-index and reduction of particle recycling was crucial to achieve the non-inductive plasma current start-up (PCS) successfully. Especially the controllability of particle recycling should be improved by wall conditioning based on successive plasma production and wall cleaning with electron cyclotron resonance heating (ECR) plasmas induced by RF in frequency of 2.45GHz., 15th International Congress on Plasma Physics (ICPP2010) & 13th Latin American Workshop on Plasma Physics (LAWPP2010), 8–13 August 2010, Santiago, Chile

Phosphatidylinositol 3 kinases (PI-3 kinases) play a crucial role in the inositol phospholipid signaling pathway. The effect of wortmannin, an inhibitor of PI-3 kinases, on the suppression of thermotolerance development was investigated in the temperature-sensitive cell line tsAF8. When wortmannin was added immediately after the preheating, the thermotolerance was suppressed, with this suppression being dose-dependent from 0.01 to 0.1 microM, but not dose-dependent from 0.1 to 20 microM. Our results suggest that PI-3 kinases might play an important role in thermotolerance development in tsAF8 cells.

Our previous study using a new microscopic system indicated that apoptotic cells undergo secondary necrosis during treatment with anti-Fas antibody and calcium. In this study, we compared the time-lapse appearance of apoptosis and secondary necrosis of Jurkat cells during treatment with anti-Fas antibody with and without calcium in individual cells. Apoptosis developed in 97% and 81% of cells during 36-hour-treatment with anti-Fas antibody with and without calcium, respectively. The apoptosis of Jurkat cells showed a characteristic pattern of time-lapse morphological change. Less than 1% of the apoptotic cells divided into apoptotic bodies. There was budding in all the other apoptotic cells, but no apoptotic bodies formed. We confirmed that secondary necrosis occurs in individual apoptotic cells during treatment with anti-Fas antibody. Neither the pattern of time-lapse morphological change nor the time interval between the beginning of apoptotic budding and secondary necrosis were related to the presence of calcium. This study clarified the characteristic pattern of time-lapse morphological change in Jurkat cells during treatment with anti-Fas antibody, and presented direct evidence that individual apoptotic cells undergo secondary necrosis. The presence of calcium did not affect the pattern of morphological change or the time interval between the beginning of apoptotic budding and secondary necrosis.

The cell-killing effects of some anticancer drugs are enhanced when accompanied by treatment with hyperthermia in vitro and in vivo. These effects are influenced by various environment conditions of tumor cells, such as pH, oxygen, and nutrition. An abiding problem is that multidrug-resistant cancer cells are often observed in the recurrent tumor after chemotherapy, but fortunately they have approximately equal sensitivity to hyperthermia as do wild-type cells. In addition, heating increases the influx of the anticancer drugs, thereby inducing a high level of intracellular accumulation. Recent reports on the mechanisms of anticancer drug enhancement via heating are reviewed.

To investigate the effects of confinement of fast electrons on poloidal beta equilibrium, experiments under different toroidal magnetic mirror ratios, MOMFC, were performed in electron cyclotron heated plasma in the spherical tokamak QUEST. The proportional constants of the relation between plasma current and vertical magnetic fields decreased with increase in MOMFC. The poloidal field null point appeared in the chamber for MOMFC > 1.8 at a plasma current value of ∼15 kA. Poloidal beta and temperature of hard X-rays increased with MOMFC. This suggests that high poloidal beta equilibrium plasma is produced by better confinement of energetic trapped particles.

We compared adriamycin (ADR) accumulation with the intensity of intracellular fluorescence of 3,3'-(di-n-hexyl)-2,2'-oxacarbocyanine iodide (NK-2280), an indicator of cell membrane potential, after hyperthermia and examined the effects of cepharanthin (CEP) on the accumulation of ADR and NK-2280 in wild and ADR-resistant strains of Ehrlich ascites tumour (EAT) cells. Among wild 0.2 and 1-microgram ADR-resistant strains of EAT cells, intracellular accumulation of both ADR and NK-2280 decreased with an increase of ADR resistance. Hyperthermia at 42 degrees C and CEP induced a marked increase in accumulation of both ADR and NK-2280 in the ADR-resistant strains of EAT cells. The increase in ADR accumulation by hyperthermia and CEP is possibly due to an increase in the cell membrane potential and the inhibition of ADR efflux by CEP respectively. In the wild strain of EAT cells, we also evaluated the effect of extracellular pH change on ADR accumulation and the cell membrane potential and their alteration by hyperthermia and CEP. ADR accumulation decreased as pH decreased, but the cell membrane potential was not appreciably affected by pH change so far examined. Hyperthermia alone or combined with CEP significantly increased ADR accumulation in a pH range from 6.2 to 7.6. Hyperthermia increased the accumulation of ADR in the tumour cells, although its pH dependency was not completely resolved. CEP enhanced ADR accumulation more markedly in ADR-resistant cells than in wild-type cells. Therefore, the combination of hyperthermia and CEP may be very effective to increase the ADR cytotoxicity to ADR-resistant tumours.

After intensive discharge cleaning of the chamber wall, non-inductive current start-up experiments have been successfully performed in QUEST in moderate vertical fields of about 1.0–1.5 mT with positive n-index. Simultaneously, with increasing plasma current, an asymmetric toroidal flow of energetic electrons was observed and direct measurements of current driven by this asymmetric flow were taken with a newly developed Langmuir probe technique. A numerical study of the energetic electron orbits indicates that the total current is enough to play a dominant role in the formation of a closed flux surface in QUEST.

Ohmic plasma currents of up to 17 kA with a discharge duration of 0.32 s have been obtained in the Kyushu University Experiment with Steady-State Spherical Tokamak (QUEST) with the help of electron cyclotron wave (ECW) and cancellation coils (CCs). The CCs, originally installed to create a field null in the plasma breakdown phase, are essential for producing plasma current in QUEST. Although the ohmic coil current is initially biased and then reduced completely to zero to induce the plasma current in 15-20 ms, we demonstrate that the flat top of the plasma current exceeding 20 ms is maintained by the vertical field after the ohmic current is switched off. This type of operation is quite favorable for extending pulsed operation to the steady state by electron Bernstein wave current drive (EBCD).

Because QUEST tokamak has a divertor configuration with a higher κ and a negative n-index, a precise power supply with a rapid response is needed to control the vertical position of the plasma. A matrix converter is a direct power conversion device that uses an array of controlled bidirectional switches as the main power elements for creating a variable-output current system. This paper presents a novel three-phase to two-phase topological matrix converter as a proposed power supply that stabilizes the plasma vertical position and achieves unity input power factor. An indirect control strategy in which the matrix converter is split into a virtual rectifier stage and a virtual inverter stage is adopted. In the virtual rectifier stage, the instantaneous active power and reactive power are decoupled on the basis of system equations derived from the DQ transformation; hence, unity power factor is achieved. Space vector pulse width modulation is adopted to determine the switching time of each switch in the virtual rectifier; the output voltage of the virtual rectifier is adjusted by the virtual inverter stage to obtain the desired load current. Theoretical analyses and simulation results are provided to verify its feasibility.

This paper presents a scheme for combining a Langmuir probe with a fast camera for measurement of the behavior of blob-like structures in the boundary region of an electron cyclotron resonance (ECR) heating plasma in Q-shu University Experiment with a Steady-State Spherical Tokamak (QUEST, major radius, R = 0.68 m, minor radius, a = 0.40 m, and toroidal magnetic field, Bt = 0.25 T at R = 0.64 m). The frame rate of the camera was typically set to 40,000 frames per second (FPS) with 192 × 144 pixels per frame. Radial motion of blob-like structures was observed in the half of the plasma space where the probe head was located. A radially movable and rotatable probe system was used to measure the floating potential from single unbiased tips, the potential of the positively biased tip, and the ion saturation current in two orthogonal directions in the outboard midplane region. Time series of the ion saturation current measured by the Langmuir probe and of pixels in a 40,000 FPS movie were compared and cross-correlated. The results of the two diagnostics agreed well, and the spatial scale was found to be of the same as the size of the probe head. The ion saturation current was asymmetric in terms of the time the blob-like structure was passing; fast camera imaging also clearly demonstrated the blobs' filamentary structures and radial motion at the edge of QUEST. This means that plasma in the blob-like structure hunches over, like blobs in other devices. The typical radial velocity of the structures is ∼1 km/s, and the structures were accelerated along their path of radial motion from the inner to the outer parts of the vacuum vessel.

It is important to determine the best method for reconstructing the magnetic flux when eddy currents are significantly induced during magnetic measurement in spherical tokamaks (STs). Four methods for this reconstruction are investigated, and the calculated magnetic fluxes are compared to those measured in the cavity of a vacuum vessel. The results show that the best method is the one that uses currents from virtual coils for reconstruction. In this method, the placement of the virtual coils is optimized with numerical simulations using the Akaike information criterion (AIC), which indicates the goodness of fit of models used to fit measured data. The virtual coils are set on a line 15 cm outside the vacuum vessel.

Various phenomena of plasma-wall interactions during long duration discharges in TRIAM-1M are investigated from macroscopic and microscopic viewpoints. It is found that the density dependence of the hydrogen neutral flux decay length is not very sensitive to the density (i.e. ne−0.2 ). Neutral transport through the scrape-off layer is important for structural formation of hydrogen recycling. The hydrogen retention in the co-deposited layer, which was obtained using a material probe during long duration discharges, is consistent with the global wall pumping rate estimated from particle balance analysis. The wall temperature and co-deposition play important roles on hydrogen re-emission and hydrogen absorption, respectively. Oxygen impurities should affect the erosion and deposition properties of the plasma-facing wall as well as the hydrogen retention property of the co-deposited layer. The co-deposition of hydrogen with molybdenum and the oxygen impurities both play important roles in the hydrogen recycling.

QUEST focuses on the steady state operation of the spherical tokamak by controlled PWI and electron Bernstein wave current drive. One of the main purposes of QUEST is an achievement of long duration discharge with MW-class injected power. As the result, QUEST should be operated in the challenging region on heat and particle handling. To do the particle handling, high temperature all metal wall up to 623 K and closed divertors are planned, which is to realize the steady-state operation under recycling ratio, R = 1. This is a dispensable check to DEMO, because wall pumping should be avoided as possible in the view of tritium retention. The QUEST project will be developed in increment step such as, I. low β steady state operation in limiter configuration, II. low β steady state operation in divertor configuration, III. relatively high β steady state operation in closed divertor configuration. Phase I in the project corresponds to these two years, and final goal of phase I is to make full current drive plasma up to 20 kA. Closed divertor will be designed and tested in the Phase II. QUEST is running from Oct., 2008 and the first results are introduced.

For initial plasma production, an induction electric field generated by applying voltage to a poloidal field (PF) coil system is used to produce a Townsend avalanche breakdown. When the avalanche margins are small, as for the International Thermonuclear Experimental Reactor (ITER) in which the induction electric field is about 0.3 V/m, the assistance of radio-frequency waves (RF) is provided to reduce the induction electric field required for reliable breakdown. However, the conditions of RF-assisted breakdown are not clear. Here, the effects of both RF and induction electric field on the RF-assisted breakdown are evaluated considering the electron loss. When traveling loss is the dominant loss, a simple model of an extended Townsend avalanche is proposed. In this model, the induction electric field required for RF-assisted breakdown can be decreased to half that required for induction breakdown.

A large diameter diaphragmless shock tube has been recently developed and designed to perform detailed studies of CO2-N2 gas-dynamic laser (GDL). This large diameter diaphragmless shock tube offers various advantages over the conventional shock tubes (diaphragm-type) as longer test times, higher degree of reproducibility of shock-tube data, and especially low-impurity operation condition. The latter advantage is experimentally demonstrated herein, which is very critical issue in the CO2-N2 GDL studies. A supersonic nozzle section was mounted at the end wall of the shock tube and instrumented for simultaneous measurement of laser output power and energy. The GDL action in a CO2-N2 mixture under low impurity condition has been obtained by using the large diameter diaphragmless shock tube for the first time.

A new technique to measure the current profile in plasmas with asymmetric distribution function such as lower hybrid current drive (LHCD) by using hard X-ray (HXR) energy spectrum measurement along the top and bottom identical line of sights (ILOS) is proposed and is applied to the full and partially LHCD plasmas on the TRIAM-1M tokamak at the first time in the world. The pitch angles were measured at R - R0 = ±2.5 cm, where R, R0 mean the major radii of the ILOS and the magnetic axis, respectively. The measured pitch angle of the magnetic field inverted at the magnetic axis estimated magnetic measurement in partially LHCD plasmas. This indicates that the difference of the measured pitch angles is caused by the plasma current in the plasma and this new method is available in detecting the current profile in tokamaks. In full LHCD plasma, no difference between the HXR signals along the top and bottom ILOS appear. This indicates that the current density around the magnetic axis was reduced compared with that in partially LHCD plasmas. This observation is no contradiction with power deposition of LHCD.

A simple model of radio frequency wave (RF) assisted breakdown based on Townsend avalanche theory is proposed for the purpose of evaluating the effect of RF on Townsend avalanche breakdown. According to this model, the required minimum electric field for RF-assisted breakdown can be decreased down to half of that for breakdown by the induction electric field alone. The electric field of RF reaches a minimum when the frequency of the RF is equal to the electron cyclotron frequency.

細胞周期による細胞蛋白量の変化をfluorescein isothiocyanate (FITC) とpropidium iodide (PI) とによる二重染色を行った指数増殖期にあるHeLa細胞において, flow cytometryにより測定した.FITCとPIとの螢光スペクトルは, 一部で重複する.そのため螢光量の一部を互いに差し引く補正装置が必要となる.X-Yドットプロット表示とgated analysisとにより, 細胞ごとの差は大きいものの, 細胞蛋白量は細胞周期の進行に従って増加し, 細胞分裂によって半分となることが示された.

The protective effect of glutathione (GSH) and cysteamine (MEA) on radiation-induced mitotic delay in cultured mammalian L-5 cells was studied. Cells treated with 20 mM of GSH during irradiation with 2 Gy (200 rad) showed faster recovery of the mitotic index than control cells irradiated without chemical treatment; however, GSH had no effect on mitotic delay time. Inhibition of mitosis was observed with 80, 100, and 120 mM of GSH. Cells treated with 5 mM of MEA during irradiation also showed faster recovery of the mitotic index than the controls, but in addition the delay time was shortened. Progression of G2-phase cells treated with 5-fluorouracil to mitosis after irradiation was protected by MEA but not by GSH. Progression of S-phase cells labeled with 3H-thymidine to mitosis was accelerated by both agents during irradiation.

To study surface adsorption of cationic surfactants on a hydrophilic polymer latex, ζ-potential of styrene/2-hydroxyethyl methacrylate [P (St/HEMA)] copolymer latex was measured in aqueous solutions of alkyl pyridinium bromides (abbr. APB, CnH2n+1NC5H5Br; n=12 : DPB, n=14 : TPB and n=16 : HPB). Hydrophobic polystyrene (PS) latex was used as the reference sample. The amount of surfactant adsorbed per unit area of the latex was calculated from the ζ-potential value. With increasing concentration of surfactant, the sign of the ζ-potential of the latex changed from negative to positive and the amount of surfactant adsorbed increased. The surfactant adsorption increased with the hydrocarbon chain length of APB in the order HPB > TPB > DPB. These results can be explained by electrostatic bonds and the van der Waals force between the latex and surfactant. The amount of surfactant adsorbed on the P (St/HEMA) latex was less than that on the PS latex. The free energy of adsorption ΔG for a surfactant on a latex was calculated from parameters such as the slope of the ζ-log Cs (Cs : the concentration of surfactant) curve. The negative value of ΔG increased with chain length of the surfactant. Also this value on the P (St/HEMA) latex was less than that on the PS latex. The large positive value of the entropy of adsorption ΔG indicates the importance of entropic interactions and the formation of hydrophobic bonds as driving forces for adsorption of the surfactant on the latex surface. The ΔG for P (St/HEMA) latex had a smaller positive value than that for PS latex. It is concluded that the adsorbability of surfactant on P (St/HEMA) latex is lower than that on the PS latex, since hydrophilic poly-HEMA layer is present on the surface of the P (St/HEMA) latex.

Swelling phenomena of the liver mitochondria were investigated in rats whose whole bodies had been subjected to X-irradiation of 1000R. The rats were killed at 4.5, 6, 17, 22 and 52 hours after irradiation. The rate of swelling of the mitochondria in reaction to various agents decreased after irradiation, reaching its lowest level at 6 hours, but gradually recovering the normal level after 22 hours. Swellings of mitochondria induced by ferrous and ferric ions in a KCl-Tris-HC1 medium were accelerated by X-irradiation, reaching the maximum at 22 hours. A large amount of lipid peroxide, measured by the degree of formation of thiobarbiturate color matter, was formed in mitochondria treated by ferrous and ferric ions. This formation showed remarkable correlation with the mitochondrial swelling. Irradiation shortened the lag period for the formation of lipid peroxide with Fe2+, as was also observed in the case of mitochondrial swelling.

Propene adsorbed on zinc oxide was oxidized to surface formate and acetate species as well as OH groups via an unidentified precursor.

Acyclovir (ACV), a new antiviral drug, was used to investigate its effect of radiosensitivity in tumors in vivo. In in vivo experiments with Sarcoma-180 transplanted into the ICR mouse and FM3A transplanted into the C3H mouse, ACV enhanced the radiosensitivity of both tumors. In S-180, radiation effects were enhanced by treatment with 100 mg/kg of ACV from 30 min before to 60 min after irradiation. In S-180 treated by 400 mg/kg of ACV, the enhancement ratio was approximately 2.0, as evaluated by the growth delay method. In the FM3A tumor treated by 20 mg/kg of ACV, the enhancement ratio was approximately 1.3, as evaluated by tumor cure (TCD50 assay). ACV is already clinically used as an antiviral drug. Its ability to radiosensitize tumors could therefore have clinical potential when combined with radiotherapy.

The intracellular uptake, retention and cytotoxicity of adriamycin (ADR) combined with a biscoclaulin alkaloid, cepharanthine, were investigated by flow cytometry in NIH 3T3 cells. Cepharanthine suppressed the efflux of ADR in a similar fashion to verapamil. The intracellular uptake and retention of ADR were increased gradually by 0.1 to 1 microgram/ml of cepharanthine and reached a plateau at greater than 1 microgram/ml. Cepharanthine, which had no toxic action on survival, increased intracellular ADR uptake by about 20% for 1 h incubation at 37 degrees C, and increased cellular ADR retention after incubation in an ADR-free medium for 4 h from 15% to 75%. The cytotoxicity of ADR was enhanced 5-fold in the cells pre- and co-incubated with cepharanthine. When cepharanthine was present in the medium before, during and for colony formation (10 days) after incubation with ADR, the cytotoxicity increased to about 300-fold. Furthermore, an increase in intracellular uptake of ADR was induced by an elevated temperature of 43 degrees C, and the efflux of ADR was inhibited by cepharanthine. A high level of intracellular ADR was maintained during the treatment. These results suggest a possible novel use of cepharanthine to improve the drug sensitivity of tumors resistant to ADR.

To clarify the relationship between alpha-fetoprotein (AFP) production and cell growth in hepatocellular carcinoma an immunohistochemical method was used to examine the geographical distribution of AFP-producing cells and DNA-synthesizing cells in hepatoma tissue which was formed by subcutaneous transplantation of the human hepatoma cell line, HuH-7, into athymic mice. DNA-synthesizing cells were localized to the perivascular restricted areas where AFP-producing cells were preferentially demonstrated. The fall of the labeling index of bromodeoxyuridine was accompanied by a decrease in AFP production. The results indicate that AFP is produced mainly by the cells participating in tumor growth but not by quiescent cells.

The cellular uptake of Adriamycin (ADR) by solid tumors consisting of Ehrlich ascites tumor cells (EATC) was investigated. The intracellular levels of ADR in the EATC were measured by flow cytometry. The EATC tumors were heated at various temperatures for 30 min after the in vivo administration of ADR to the mice into which the EATC were inoculared. The amount of intracellular ADR in the EATC excised from the mice treated with 40°C hyperthermia was increased by 80% over that determined for those treated at body temperature. However, the quantity of ADR in the EATC excised from mice which received 43°C hyperthermia was similar to that for those treated at body temperature. These results indicate that combined therapy using hyperthermia and ADR has both synergic and additive effects, depending on the temperatures used for hyperthermia.