All corals have a common structure: two tissue layers enclose a lumen, which forms the gastric cavity. Few studies have described the processes occurring inside the gastric cavity and its chemical ...and biological characteristics. Here, we show that the coral gastric cavity has distinct chemical characteristics with respect to dissolved O
2
, pH, alkalinity, and nutrients (vitamin B
12
, nitrate, nitrite, ammonium, and phosphate) and also harbors a distinct bacterial community. From these results, the gastric cavity can be described as a semi-closed sub-environment within the coral. Dissolved O
2
shows very low constant concentrations in the deepest parts of the cavity, creating a compartmentalized, anoxic environment. The pH is lower in the cavity than in the surrounding water and, like alkalinity, shows day/night variations different from those of the surrounding water. Nutrient concentrations in the cavity are greater than the concentrations found in reef waters, especially for phosphate and vitamin B
12
. The source of these nutrients may be internal production by symbiotic bacteria and/or the remineralization of organic matter ingested or produced by the corals. The importance of the bacteria inhabiting the gastric cavity is supported by the finding of a high bacterial abundance and a specific bacterial community with affiliation to bacteria found in other corals and in the guts of other organisms. The findings presented here open a new area of research that may help us to understand the processes that maintain coral health.
All-optical flip-flop operation of multimode interference bistable laser diodes (MMI-BLDs) was experimentally demonstrated for the first time. The MMI-BLD was prepared with a conventional ridge ...waveguide laser diode fabrication procedure, suitable for photonic integrated circuits. Bistable switching via two-mode bistability was obtained with approximately 0-dBm input powers due to cross-gain saturation and the saturable absorbers. Bit-length conversion was successfully obtained with noninverted and inverted outputs. This device will be useful in future photonic systems requiring all-optical latching functions such as optical memory, self-routing, and further optical signal processing.
To identify predictive molecular markers for gemcitabine resistance, we investigated changes in the expression of four genes associated with gemcitabine transport and metabolism during the ...development of acquired gemcitabine resistance of pancreatic cancer cell lines. The expression levels of human equilibrative nucleoside transporter-1 (hENT1), deoxycytidine kinase (dCK), RRM1, and RRM2 mRNA were analysed by real-time light cycler-PCR in various subclones during the development of acquired resistance to gemcitabine. Real-time light cycler-PCR demonstrated that the expression levels of either RRM1 or RRM2 progressively increased during the development of gemcitabine resistance. Expression of dCK was slightly increased in cells resistant to lower concentrations of gemcitabine, but was decreased below the undetectable level in higher concentration-resistant subclones. Expression of hENT1 was increased in the development of gemcitabine resistance. As acquired resistance to gemcitabine seems to correlate with the balance of these four factors, we calculated the ratio of hENT1 x dCK/RRM1 x RRM2 gene expression in gemcitabine-resistant subclones. The ratio of gene expression decreased progressively with development of acquired resistance in gemcitabine-resistant subclones. Furthermore, the expression ratio significantly correlated with gemcitabine sensitivity in eight pancreatic cancer cell lines, whereas no single gene expression level correlated with the sensitivity. These results suggest that the sensitivity of pancreatic cancer cells to gemcitabine is determined by the ratio of four factors involved in gemcitabine transport and metabolism. The ratio of the four gene expression levels correlates with acquired gemcitabine-resistance in pancreatic cancer cells, and may be useful as a predictive marker for the efficacy of gemcitabine therapy in pancreatic cancer patients.
The influences of upper-coil and lower-coil current modulation of tandem-type modulated induction thermal plasma (tandem-MITP) were studied for silicon nanoparticle synthesis using both experimental ...and numerical approaches. The modulation condition was set to three conditions of non-modulation, lower-coil current modulation only, and simultaneous upper-coil and lower-coil current modulation. The experimentally obtained results indicate that simultaneous modulation of the upper-coil and lower currents provides smaller nanoparticles with a lower standard deviation of particle size. This result suggests that large modulation of two coil currents can offer more rapid quenching of the temperature field in modulated induction thermal plasma. The developed numerical model also predicted provision of smaller nanoparticles by high quenching because of strong entrainment gas flow by the simultaneous modulation of upper-coil and lower coil currents. Comparison was made between the numerical result and experimentally obtained results in terms of time variation in the radiation intensity distribution, and particle size distribution, indicating fair agreement between them. From these experimentally obtained and numerical results, simultaneous modulation of the upper-coil and lower-coil currents was found to be preferable for nanoparticle synthesis.
In this paper, numerical calculations were made for Ar loop-type inductively coupled thermal plasma (loop-ICTP). The loop-ICTP was developed originally by the authors’ group for rapid surface ...modification of large areas. Loop-ICTP is sustained with a unique three-dimensional (3D) configuration inside a circular loop quartz tube and on the substrate. A 3D and two-temperature thermofluid thermal plasma model was adopted for this calculation. Mass, momentum, and energy conservation equations were solved using a Maxwell equation for vector potential, an electron energy transport equation, and Saha’s equation in the 3D space. Results indicate that Ar loop-ICTP can be sustained and formed in the loop tube and also on the substrate. Moreover, the heavy particle temperatures reaches 1800–2000 K, whereas the electron temperature is about 10,000 K. Loop size effects on the gas temperature and gas flow field were also investigated using the developed model. Results show that adoption of a larger loop tube can be expected to improve the plasma uniformity on the substrate when applied to rapid surface modification.
Abstract Oncoplastic breast conserving surgery (BCS) has emerged as a third option between conventional BCS and mastectomy. Oncoplastic BCS includes two fundamentally different approaches: volume ...replacement and volume displacement. The former involves partial mastectomy and immediate reconstruction of the breast with the transposition of autologous tissue from elsewhere, while the latter involves partial mastectomy and using the remaining breast tissue to fill the defect resulting from extirpation of the tumor. There are several benefits associated with oncoplastic BCS. First, it allows partial mastectomy without cosmetic penalties, and can achieve better cosmetic outcomes than total mastectomy with immediate breast reconstruction. Second, it avoids the need for total mastectomy in an increasing number of patients without compromising local control. Third, partial breast reconstruction is less extensive and has fewer complications than conventional procedures. Partial mastectomy and partial breast reconstruction can be carried out either simultaneously as a one-stage procedure, or using a two-stage approach. Although patients prefer a one-stage procedure, it requires intraoperative confirmation of complete tumor excision using frozen-section analysis. Moreover, oncoplastic BCS requires combined skills, knowledge, and understanding of both oncological and plastic surgeries, which may be optimally achieved by an oncoplastic surgeon.
This paper describes effects of intermittent Ar/CH
4
quenching gas (QG) injection on the size and composition of Si/C nanoparticles synthesized using pulse-modulated induction thermal plasma (PMITP). ...Time-controlled feeding of feedstock (TCFF), with synchronous and intermittent injection of silicon feedstock powder to the PMITP, was used for high-rate production of Si nanoparticles. Also, Ar QG was supplied intermittently from the chamber wall to enhance the cooling effect further. The QG also included CH
4
as a carbon source gas for Si/C nanoparticle synthesis. Intermittent QG injection timing was studied for the composition of Si/C nanoparticles. The synthesized particles were analysed using FE-SEM, XRD, TEM, EDS, and Raman spectroscopy. Furthermore, numerical thermofluid simulation was also conducted to obtain the time varying temperature distribution in the reaction chamber, considering intermittent QG injection. From this numerical calculation, the dependence of the minimum temperature on the QG injection timing was found. The above experimental and numerical results indicate that carbon-coated Si nanoparticles can be synthesized when QG is injected at appropriate timing into the PMITP with temperatures of 1000–2000 K.
PDF
