A CW 28 μm water vapor laser for plasma diagnostics

A high-power CW 27.972 μm water vapor laser has been constructed in order to use as a light source of an interferometer for plasma diagnostics. The laser consists of 220 cm length and 2.0 cm small bore Pyrex glass discharge tube, semi-confocal resonator and Michelson coupler. From the measurement of cavity detuning curves, it is found that two waveguide modes, EH₁₁ and EH₂₁ oscillate. The increase of the output power is found to become more than seven times larger by adding He(50%)?H₂(50%) mixed gas. Under the optimum condition, the maximum output power of 65 mW or the output power per unit cavity volume of 83 μW/cm³ is obtained.     

Evaluating the Effect of Lenvatinib on Sorafenib-Resistant Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related deaths worldwide. Sorafenib has been used as a first-line systemic treatment for over a decade. However, resistance to sorafenib limits patient response and presents a major hurdle during HCC treatment. Lenvatinib has been approved as a first-line systemic treatment for advanced HCC and is the first agent to achieve non-inferiority against sorafenib. Therefore, in the present study, we evaluated the inhibition efficacy of lenvatinib in sorafenib-resistant HCC cells. Only a few studies have been conducted on this topic. Two human HCC cell lines, Huh-7 and Hep-3B, were used to establish sorafenib resistance, and in vitro and in vivo studies were employed. Lenvatinib suppressed sorafenib-resistant HCC cell proliferation mainly by inducing G1 cell cycle arrest through ERK signaling. Hep-3B sorafenib-resistant cells showed partial cross-resistance to lenvatinib, possibly due to the contribution of poor autophagic responsiveness. Overall, the findings suggest that the underlying mechanism of lenvatinib in overcoming sorafenib resistance in HCC involves FGFR4-ERK signaling. Lenvatinib may be a suitable second-line therapy for unresectable HCC patients who have developed sorafenib resistance and express FGFR4.     

Pot Life Problem and its measure with a reduced smoke propellant production

Typical reduced smoke type composite propellants mainly composed of hydroxyl-terminated polybutadiene (HTPB) and ammonium perchlorate (AP) have a drawback that these propellant grains have a high response function of the burning rate to cause acoustic pressure oscillation. The addition of a small fraction (0.5% ∼ 1.2wt%) of zirconium (Zr) or zirconium oxide powders to propellant compositions has been known to be effective for suppressing such a combustion instability. It is also notified, however, Zr powder would incur the acceleration of urethance forming reaction so as to make the pot life of the HTPB/AP propellant dough shorter. This paper reports that tetracycline (TC) is available to offset such a trouble in curing process brought about by Zr powder addition.     

Combustion Aspects of Sodium Azide and its mixtures with potassium perchlorate and burning catalysts

Linear burning rate, thermal aualysis, temperature profile, flame structure and cryogenic burnability for the mixtures of sodium azide (SA) of different particle sizes (3.5 μm, 22 μm, and 67 μm), potassium perchlorate (KP) and with or without three kinds of burning catalysts (GeO₂, Er₂O₃, and Y₂O₃) have been investigated. The linear burning rates increase with the KP content up to 33Wt% for similar SA particle size. The temperature-time histories in the vicinity of burning surface were obtained with 20 μm Type K thermocouple embedded in a Strand. The burning surface temperaturres of neat SA and of the SA/KP mixtures are nearly 350°C and 350°C ∼ 550°C, respectively, while the existence of the decomposition surface at 250 °C and condensed layer was suggested with SA/KP mixtures. In visual observation for the flame structure, the front of luminous flame zone appers to be in contact with the condensed phase surface. For example, however, the temperature profile suggests that there exists finitc distance from decomposition surface to flame front in the order of 0.05 mm ∼ 0.1 mm at 1 MPa for SA/KP = 80/20. The differential thermal analysis indicates that the tested catalysts have retarding effect on SA combustion, but a positive effect on neat KP decomposition in spite of being impotent for the burning rate increase of the SA/KP mixture. It was also found that SA strands containing appropatiae fractions of KP can hurn even in liquid nitrogen.     

FTIR spectroscopic study on the Interaction between Ammonium Perchlorate and Bonding Agents

The interaction between ammonium perchlorate and bonding agents has been investigated by means of Fourier transform infrared spectroscopy (FTIR). The analysis results endorse that the interfacial bonding force is hydrogen bond for aziridine type compounds and ionic bond for alkylene polyamine derivatives, respectively.     

Antitumor Effect of Regorafenib on MicroRNA Expression in Hepatocellular Carcinoma Cell Lines

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is one of the leading causes of cancer-related deaths worldwide. Regorafenib, a multi-kinase inhibitor, is used as a second-line treatment for advanced HCC. Here, we aimed to investigate the mechanism of the antitumor effect of regorafenib on HCC and evaluate altered microRNA (miRNA) expression. Cell proliferation was examined in six HCC cell lines (HuH-7, HepG2, HLF, PLC/PRF/5, Hep3B, and Li-7) using the Cell Counting Kit-8 assay. Xenografted mouse models were used to assess the effects of regorafenib in vivo. Cell cycle analysis, western blotting analysis, and miRNA expression analysis were performed to identify the antitumor inhibitory potential of regorafenib on HCC cells. Regorafenib suppressed proliferation in HuH-7 cell and induced G0/G1 cell cycle arrest and cyclin D1 downregulation in regorafenib-sensitive cells. During miRNA analysis, miRNA molecules associated with the antitumor effect of regorafenib were found. Regorafenib suppresses cell proliferation and tumor growth in HCC by decreasing cyclin D1 via alterations in intracellular and exosomal miRNAs in HCC.     

Ce³+-induced exopolysaccharide production by Bradyrhizobium sp. MAFF211645

Ce³⁺, a rare earth element (REE), has been widely used in high-technology industries. Despite the importance of Ce³⁺ in the fields of chemistry and physics, the role of Ce³⁺ in biology has been ignored. To investigate physiological effects of Ce³⁺ on microorganisms, we screened microorganisms that showed peculiar growth in the presence of Ce³⁺. We isolated a free-living soil bacterium that produced exopolysaccharide (EPS) around its colonies on 1/100 nutrient agar with 30 μM CeCl₃ or 1.0% d-mannitol. The bacterium was identified as Bradyrhizobium sp. by morphological, biochemical, and physiological tests as well as 16S rDNA sequence analysis. La³⁺, Pr³⁺, and Nd³⁺ also induced EPS production in large quantities, while Sm³⁺ did in small amounts. However, other heavier REEs from Eu³⁺ to Lu³⁺, and metals such as Na⁺, Al³⁺, K⁺, Ca²⁺, V³⁺, Cr³⁺, Co²⁺, Ni²⁺, Sr²⁺, Ba²⁺, and Pb²⁺ did not induce EPS production. The mean molecular weight of EPS was estimated to be approximately 1 × 10⁶ by Sepharose CL-4B column chromatography. TLC revealed that EPS was composed of l-rhamnose. Quantitative analysis of alditol acetate derivatives of acid hydrolyzate of EPS by GLC revealed that EPS was composed of more than 95% l-rhamnose, indicating that this EPS was a rhamnan. The spectrum of FT-IR of the rhamnan demonstrated that l-rhamnose residues in the rhamnan were α-linked. GC/MS analysis of methylated alditol acetate derivatives of the rhamnan demonstrated that it was composed of main chain α-(1→4)-linked l-rhamnopyranosyl residues. From spectral analyses of ¹H-NMR and FT-IR, EPS produced in the presence of 1.0% d-mannitol was found to be structurally similar to rhamnans.     

Tooth pulp neurons in the caudal medulla oblongata of the cat

The medulla oblongata caudal to the obex was explored for neurons responsive to tooth pulp (TP) stimulation in cats. Four different subclasses of TP neurons were found. The latter included TP specific (TPS) neurons, trigeminal wide dynamic range (trigeminal WDR) neurons with TP input, trigeminal subnucleus reticularis ventralis (trigeminal SRV) neurons with TP input and convergent reticular formation (convergent RF) neurons with TP input. TPS neurons were located in the dorsal marginal rim of the trigeminal subnucleus caudalis, i.e., in the marginal layer or the outer zone of substantia gelatinosa. WDR neurons with TP input were found in the neck region of medullary dorsal horn which corresponds to the lateral part of subnucleus reticularis dorsalis (SRD). Trigeminal SRV neurons with TP input were located in the lateral part of SRV. Convergent RF neurons with TP input were found in the middle third of the caudal bulbar RF consisting of SRD and SRV. Both TPS neurons and WDR neurons with TP input included trigeminothalamic neurons as evidenced by the antidromic activation from the nucleus ventralis posteromedialis of the contralateral thalamus. A significant proportion of both trigeminal SRV and convergent RF neurons with TP input were antidromically activated by stimulation of the nucleus centralis lateralis of the contralateral thalamus. The former two subclasses may subserve the sensory-discriminative aspect of toothache, while the latter two subclasses, the emotional-motivational aspect.