STW gas sensors using plasma-polymerized allylamine

Gas sensors generally consist of two major components: a gas recognition element which provides the specificity and selectivity of the measurement and a physical transducer which translates the gas absorption or desorption event into electronic signal. In this paper, plasma polymerized allylamine (PPAa) film is used as a gas recognition element and a surface transverse wave (STW) device is used as a physical transducer. It is confirmed that STW sensor devices coated with PPAa films provide high sensitivity for moisture. The STW sensor device with a 63 nm PPAa film provided twenty four times higher sensitivity than that of a non-coated STW device. In addition, the chemical structure of PPAa films is characterized by the FT-IR and the contact angle measurement.     

In Vitro Tumor Cell-Binding Assay to Select High-Binding Antibody and Predict Therapy Response for Personalized 64Cu-Intraperitoneal Radioimmunotherapy against Peritoneal Dissemination of Pancreatic Cancer: A Feasibility Study

Peritoneal dissemination of pancreatic cancer has a poor prognosis. We have reported that intraperitoneal radioimmunotherapy using a ⁶⁴Cu-labeled antibody (⁶⁴Cu-ipRIT) is a promising adjuvant therapy option to prevent this complication. To achieve personalized ⁶⁴Cu-ipRIT, we developed a new in vitro tumor cell-binding assay (⁶⁴Cu-TuBA) system with a panel containing nine candidate ⁶⁴Cu-labeled antibodies targeting seven antigens (EGFR, HER2, HER3, TfR, EpCAM, LAT1, and CD98), which are reportedly overexpressed in patients with pancreatic cancer. We investigated the feasibility of ⁶⁴Cu-TuBA to select the highest-binding antibody for individual cancer cell lines and predict the treatment response in vivo for ⁶⁴Cu-ipRIT. ⁶⁴Cu-TuBA was performed using six human pancreatic cancer cell lines. For three cell lines, an in vivo treatment study was performed with ⁶⁴Cu-ipRIT using high-, middle-, or low-binding antibodies in each peritoneal dissemination mouse model. The high-binding antibodies significantly prolonged survival in each mouse model, while low-and middle-binding antibodies were ineffective. There was a correlation between in vitro cell binding and in vivo therapeutic efficacy. Our findings suggest that ⁶⁴Cu-TuBA can be used for patient selection to enable personalized ⁶⁴Cu-ipRIT. Tumor cells isolated from surgically resected tumor tissues would be suitable for analysis with the ⁶⁴Cu-TuBA system in future clinical studies.     

Electron field emission from diamond-coated carbon foam

This article is a continuation of a previous work [Diamond & Relat. Mater. 13 (2004) 2113] on the observation of electron field emission patterns from B-doped diamond films, in which a preliminary result of experiment using carbon sponge (carbon foam) as a material for the emission source was presented. In the present work, the carbon foam was first soaked in nanodiamond powder-suspended water overnight, and microwave plasma chemical vapor deposition was done to locally deposit diamond particles and films on the carbon foam. It was found that at an applied electric field of 6 V/μm, the emission current from the diamond-coated carbon foam was 7.6 mA/cm², which was more than one order of magnitude higher than that from a bare carbon foam.     

Preparation and properties of poly(arylene) containing Si unit-bridged diphenylamine

Si (monosilane, disilane, and disiloxane) unit-bridged diphenylamine-containing poly(arylene) PARs were prepared and properties of PARs were compared with the relative Si unit-bridged diphenylamine homopolymers. PARs were prepared by palladium-catalyzed polycondensation between Si unit-bridged diphenylamine and distannyl- or diboryl-aromatic compound. PAR with disiloxane unit-bridged diphenylamine was also prepared by oxidation of PAR with disilane unit-bridged diphenylamine. Optical properties and electrochemical properties of PAR depended on not only bridging Si unit but also introduced arylene unit.     

Theoretical time-domain study of self-imaging properties in a multimode interference coupler

We report a theoretical and numerical study of self-imaging properties, including time domain and pulse spreading, caused by modal group-delay dispersion in generalized N x N multimode interference devices achieved by using a mode-propagation analysis and finite-difference time-domain method. It was found that the spatial self-imaging condition does not realize temporal self-imaging but lets waveforms separate whose shape depends on input position and input field distribution. Pulse spreading, which is sensitive to beam diameter, has a very large variation (420 fs) among input positions as well as rising to a very high 900 fs in response to a 21 fs and spatially Gaussian pulse for the conveniently smallest size with 10 channels.     

Dependence of process characteristics on atomic-step density in catalyst-referred etching of 4H-SiC(0001) surface

Catalyst-referred etching (CARE) is a novel abrasive-free planarization method. CARE-processed 4H-SiC(0001) surfaces are extremely flat and undamaged over the whole wafer. They consist of single-bilayer-height atomic steps and atomically flat terraces. This suggests that the etching properties depend principally on the atomic-step density of the substrate surface. We used on-axis and 8 degrees off-axis substrates to investigate the processing characteristics that affect the atomic-step density of these substrates. We found a strong correlation between the removal rate and the atomic-step density of the two substrates. For the on-axis substrate, the removal rate increased with increasing surface roughness, which increases with an increasing atomic-step density. The removal rate ratio is approximately the same as the atomic-step density ratio of the two substrates.     

Influence of Cu on nanostructure of Fe3O 4 particles

Cu is effective on the refinement of Fe₃O₄ rust particles but its mechanism is not clarified. In this study, the influence of Cu on the nanostructure of Fe₃O₄ particles was investigated through a detailed analysis of the characteristics of the artificially synthesized Fe₃O₄ particles formed with Cu²⁺ by various means. X‐ray absorption fine structure analysis showed that Cu is substituted for octahedral Fe and exists as Cu_xFe_(3‐x)O₄ in Fe₃O₄. The first‐principle calculation showed that lattice strain resulted around the substituted Cu. These results suggest that this lattice strain around substituted Cu inhibited the lattice growth and contributed to the refinement of Fe₃O₄ particles.