Plate mode propagation losses in solidly mounted resonators

This paper investigates the acoustic losses of propagating eigenmodes through the acoustic mirror of a solidly mounted resonator (SMR) to clarify how resonator properties are influenced by reflection coefficients for the thickness shear (TS) wave as well as that for the thickness extensional (TE) wave. To this end, we analyze the effective acoustic admittance for several test structures with different mirror properties. Leaky modes are distinguished from plate-like modes and the propagation losses are quantified by calculating mode quality factors. The dependence of the propagation properties of leaky eigenmodes is compared with the mirror properties in terms of bulk wave transmission coefficients obtained by the one-dimensional Mason?s model. It is shown that the TE-like main mode couples with TS-like spurious modes, which then influence the leaky loss of the main mode as well. The coupling strength is strongly frequency-dependent and drastically changes with the mirror design. This result explains previous experimental results reported on SMR design.     

Comparison of δ13C and 14C activities of CO2 samples combusted in closed-tube and elemental-analyzer systems

For combustion of organic samples, a closed tube-combustion (CTC) method is generally used, but this method requires much time and labor. The AMS facility at the Center for Chronological Research, Nagoya University, has established a CO₂ production and purification system using an elemental analyzer (EA) connected to cryogenic traps. This system enables faster combustion and CO₂ purification of samples than does the conventional CTC method. We compared measured carbon yields, δ¹³C values and ¹⁴C activities between EA and CTC samples of carbon standards of various sample quantities. This newly developed EA system had low background ¹⁴C activity due to sample preparation; the background activity was similar to that observed for the CTC method. The EA system also showed high precision and accuracy for δ¹³C and ¹⁴C measurements. The EA sample data obtained from conventional quantities (>1 mg carbon) of standards showed good agreement with the results obtained by the CTC method and with the consensus values, though background contamination was detected for samples containing <0.5 mg carbon. Oxalic acid standards containing <0.5 mg carbon that were analyzed by the CTC method tended to have widely varying values of carbon yield, δ¹³C and ¹⁴C activity, suggesting that the CO₂ produced by combustion might have been prone to adsorption to an inner wall of the combustion tube, to CuO or to both, and that the CO₂ produced in the CTC method might have decomposed.     

The Impact of m1A Methylation Modification Patterns on Tumor Immune Microenvironment and Prognosis in Oral Squamous Cell Carcinoma

N1-methyladenosine (m1A) modification widely participates in the occurrence and progression of numerous diseases. Nevertheless, the potential roles of m1A in the tumor immune microenvironment (TIME) are still not fully understood. Based on 10 m1A methylation regulators, we comprehensively explored the m1A modification patterns in 502 patients with oral squamous cell carcinoma (OSCC). The m1A modification patterns were correlated with TIME characteristics and the m1A score was established to evaluate the effect of the m1A modification patterns on individual OSCC patients. The TIME characteristics and survival outcomes under the three m1A modification patterns were significantly distinct. OSCC patients in the high m1A score group were characterized by poorer prognosis, lower immune infiltration, lower ssGSEA score, lower expression levels of immune checkpoint molecules, and higher tumor mutation loads. The present study revealed that m1A modification might be associated with the TIME in OSCC, and has potential predictive ability for the prognosis of OSCC.     

An Object-Oriented Framework for Loop Parallelization

Generation of efficient parallel code is a major goal of a well-designed and developed parallelizing compiler. Another important goal is portability of both compiler system and the resulting output source codes. The various choices of current and future parallel computer architectures as well as the cost of developing a parallelizing compiler make portability a very important design goal. Since the design of parallelizing compilers is considerably move complex than designing conventional compilers, it is very important to achieve both efficiency and portability. To meet this dual goal, we have investigated the application of object oriented design to parallelizing compilers. Our parallelizing compiler design is based on abstractions of intermediate representations of loops and their class definitions. In this paper, we address the problem of loop parallelization and propose a framework where the loop parallelization process is divided into three phases and the optimization of loops is performed via a cyclic application of these three phases. The class of each phase is hierarchically derived from intermediate representations of loops. This facilitates the portability of the resulting parallelizing compilers. Furthermore, one of the phases uses a reservation table of hardware resources in order to obtain optimized parallel programs for given hardware resources. The validation of the proposed framework is given through the application of the object oriented design on an example program which is then parallelized efficiently.     

Learning Novel Objects for Extended Mobile Manipulation

We propose a method for learning novel objects from audio visual input. The proposed method is based on two techniques: out-of-vocabulary (OOV) word segmentation and foreground object detection in complex environments. A voice conversion technique is also involved in the proposed method so that the robot can pronounce the acquired OOV word intelligibly. We also implemented a robotic system that carries out interactive mobile manipulation tasks, which we call “extended mobile manipulation”, using the proposed method. In order to evaluate the robot as a whole, we conducted a task “Supermarket” adopted from the RoboCup@Home league as a standard task for real-world applications. The results reveal that our integrated system works well in real-world applications.     

Preparation of RuO2-silica gel composite microspheres from silicon ethoxide complex dispersion

A suspension polymerization method was modified for producing composite microspheres of silica gel or silica glass coated by a layer of fine RuO₂ particles. Pre-hydrolysed silicon tetraethoxide (TEOS) was dispersed into a mixed medium comprising cyclohexane and cyclohexanol or cyclohexane and cyclohexanone with pre-dispersed RuO₂ powders. The rate of gelation of TEOS sensitively increased with increasing content of alcohol or ketone in the dispersing medium. Faster gelation brought about smaller composite particles. Better dispersion of RuO₂ in cyclohexanone containing medium resulted in the better coating of RuO₂.     

General formulas for calculating magnetic field at a receiving loopplaced at an arbitrary position from a radiating loop in a shielded room

The standard magnetic field radiated by a small loop antenna is used for sensitivity testing of radio receivers. To avoid interference from external sources, the test is often carried out in a shielded room. A formula to obtain the intensity of the magnetic field at the receiving loop, when a small radiating loop antenna and the receiving loop antenna are placed at random locations in a shielded room, is derived. The convergence of the formula is analyzed. Using the formula, an equation is derived which expresses the shielded room error or the effect of the room on the standard magnetic field. The correlations between the calculated values of the error and the measured results are reported     

Serratia marcescens S-layer protein is secreted extracellularly via an ATP-binding cassette exporter, the Lip system

The Serratia marcescens Lip exporter belonging to the ATP-binding cassette (ABC) exporter is known to be involved in signal peptide-independent extracellular secretion of a lipase and a metalloprotease. Although the genes of secretory proteins and their ABC exporters are usually all reported to be linked in several gram-negative bacteria, neither the lipase nor the protease gene is located close to the Lip exporter genes, lipBCD. A gene (slaA) located upstream of the lipBCD genes was cloned, revealing that it encodes a polypeptide of 100 kDa and is partially similar to the Caulobacter crescentus paracrystalline cell surface layer (S-layer) protein. The Lip exporter-deficient mutants of S. marcescens failed to secrete the SlaA protein. Electron micrography demonstrated the cell surface layer of S. marcescens. The S-layer protein was secreted to the cultured media in Escherichia coli cells carrying the Lip exporter. Three ABC exporters, Prt, Has and Hly systems, could not allow the S-layer secretion, indicating that the S. marcescens S-layer protein is strictly recognized by the Lip system. This is the first report concerning secretion of an S-layer protein via its own secretion system.     

Preparation and characteristics of a binderless carbon nanotube monolith and its biocompatibility

A carbon nanotube (CNT) monolith without any binders was obtained by spark plasma sintering (SPS) treatment at 1100 °C under 40 MPa pressure. Transmission electron microscope results confirmed that this material maintained the nanosized tube microstructure of raw CNT powder after SPS treatment. The density and mechanical properties of this material were similar to cancellous bone. The material was implanted in subcutaneous tissue and femurs of rats and tissue samples were analyzed by histopathology at 1 and 4 weeks after surgery. Although some foreign body giant cells were seen around the CNTs, no severe inflammatory response such as necrosis was observed, and CNT implants were surrounded by newly formed bone in the femur. The study provides the first in vivo testing evidence that pure bulk carbon nanotubes are not a strongly inflammatory substance and have no toxicity for bone regeneration. Our study is the first successful experiment to consolidate CNTs without binders, and may provide an effective method for CNT monolith synthesis, as well as demonstrating that a binderless carbon nanotube material with a strength matching that of bone could be a candidate bone substitute material and a bone tissue engineering scaffold material.     

Formaldehyde-limited cultivation of a newly isolated methylotrophic bacterium, Methylobacterium sp. MF1: enzymatic analysis related to C1 metabolism

Formaldehyde is a highly toxic compound to most living organisms. We have isolated a bacterial strain that is able to efficiently degrade formaldehyde and use it as a sole carbon source. The isolated strain was identified as Methylobacterium sp. MF1, which could grow on formaldehyde and methanol. Methylobacterium sp. MF1 was grown in batch culture using 1.2 g/l formaldehyde as a sole carbon source, which was all consumed within 200 h. In order to decompose formaldehyde more efficiently, formaldehyde-limited chemostat cultivation of Methylobacterium sp. MF1 was investigated. Formaldehyde was consumed at 1.7 g/l/d when the dilution rate was 0.012 h(-1). Under these conditions, the cell turbidity (OD610) reached 2.0. Furthermore, when the initial turbidity was adjusted to 3.0 using methanol-grown cells, continuous cultivation could be started at an initial dilution rate of 0.008 h(-1). Using these conditions, consumption of formaldehyde could be continued for at least 600 h. The enzyme activities of cells growing as a chemostat culture, using methanol or formaldehyde as a sole carbon source, were compared to that of C1 metabolism. No difference was detected in the enzyme activities for the oxidation and assimilation of C1 compounds between the two cell-free extracts. Furthermore, methanol dehydrogenase activity was detected at the same level when formaldehyde was used as a sole carbon source. These results suggest that the resistance to the toxic effects of formaldehyde exhibited by Methylobacterium sp. MF1 is related to factors other than C1 metabolism.