Studies on the behaviour of microorganisms in sponge cake during anaerobic storage (studies on protection against microbiological deterioration of packaged food part xx iv)

The protective effect of an oxygen absorber (commercial names: Vitalon LH-250, Vitalon GSA-250, produced by Toa Kasei Industrial Co.) and an alcohol generating agent (commercial names: Antimold 102, Antimold E, produced by Froint Sangyo Co.) on the growth of microorganisms in sponge cake stored at 25 °C for 120 days was investigated. In the testing of the oxygen absorbers (oxygen-free) and the alcohol generating agents (alcohol), each sponge cake was inoculated with 3.1 × 10¹⁰ cells of the yeast Hansenula anomola IFO 1760 and was preserved in an air-tight bag (KET) with the oxygen absorbers and/or alcohol generating agent. The results obtained were as follows. In the case of sponge cake without oxygen absorber or alcohol generating agent, bacteria and yeast (including inoculated yeast) in the sponge cake rapidly increased at 25 °C for 30 days. However, in the oxygen-free and alcohol-generating cases, the changes of bacteria and yeast in the sponge cake were slight. The growth of bacteria and yeast was reduced considerably by the use of carbon dioxide generating oxygen absorbers or alcohol generating oxygen absorbers.     

Proliferation and stratification of keratinocyte on cultured amniotic epithelial cells for tissue engineering

Human amniotic epithelial cells (HAECs) are formed from amnioblasts, separated from the epiblast at about the 8th day after fertilization. Recent studies suggest that HAECs can produce various biologically active substances. In this study, the effects of cultured HAECs on keratinocytes were investigated. First of all, the effect of the medium conditioned by cultured HAECs on the proliferation of keratinocytes was examined. The conditioned medium significantly enhanced the proliferation (P<0.05). Next, the effect of co-culture with HAECs was also examined. The keratinocytes formed a stratified epithelium on day 7 after the start of co-culture. The cultured epithelium formed by the co-culture was five to six layers thick, could be detached by dispase treatment, and had sufficient strength as a sheet. These results suggest that HAECs will be a novel supplemental material for the tissue engineering of skin.     

Conductive area ratio of multiblock copolymer electrolyte membranes evaluated by e-AFM and its impact on fuel cell performance

The correlation between membrane surface morphology and fuel cell performance was investigated using a series of hydrophilic–hydrophobic multiblock copolymers based on poly(arylene ether sulfone) with different block lengths. The proton conductive regions on the membrane surface were successfully observed by using electrochemical atomic force microscopy (e-AFM). The results revealed a strong dependence of the hydrophilic/hydrophobic microphase-separated structure on the block length. The conductive area ratio (CAR) estimated from the proton conduction image decreased as the block length increased, and it was found to be closely connected with cell resistance that determines fuel cell performance. The well-defined phase-separated structure of multiblock copolymers can improve proton conductivity without any undesirable increments in water uptake or swelling, but in some instances, it affects the interfacial connection with the catalyst layer, resulting in lower fuel cell performance. The results of this study suggest the necessity for further improvement of the membrane morphology by optimizing both the casting conditions and the molecular design of the block sequences.     

Fabrication of small complex-shaped optics by plasma chemical vaporization machining with a microelectrode

We have developed plasma chemical vaporization machining by using a microelectrode for the fabrication of small complex-shaped optical surfaces. In this method, a 0.5 mm diameter pipe microelectrode, from which processing gas is drawn in, generates a small localized plasma that is scanned over a workpiece under numerical computer control to shape a desired surface. A 12 mm x 12 mm nonaxisymmetric mirror with a maximum depth of approximately 3 microm was successfully fabricated with a peak-to-valley shape accuracy of 0.04 microm in an area excluding the edges of the mirror. The average surface roughness was 0.58 nm, which is smooth enough for optical use.     

Molecular Pathogenesis of the Coronin Family: CORO2A Facilitates Migration and Invasion Abilities in Oral Squamous Cell Carcinoma

In humans, the coronin family is composed of seven proteins containing WD-repeat domains that regulate actin-based cellular processes. Some members of the coronin family are closely associated with cancer cell migration and invasion. The Cancer Genome Atlas (TCGA) analysis revealed that CORO1C, CORO2A, and CORO7 were significantly upregulated in oral squamous cell carcinoma (OSCC) tissues (p < 0.05). Moreover, the high expression of CORO2A was significantly predictive of the 5-year survival rate of patients with OSCC (p = 0.0203). Overexpression of CORO2A was detected in OSCC clinical specimens by immunostaining. siRNA-mediated knockdown of CORO2A suppressed cancer cell migration and invasion abilities. Furthermore, we investigated the involvement of microRNAs (miRNAs) in the molecular mechanism underlying CORO2A overexpression in OSCC cells. TCGA analysis confirmed that tumor-suppressive miR-125b-5p and miR-140-5p were significantly downregulated in OSCC tissues. Notably, these miRNAs bound directly to the 3′-UTR of CORO2A and controlled CORO2A expression in OSCC cells. In summary, we found that aberrant expression of CORO2A facilitates the malignant transformation of OSCC cells, and that downregulation of tumor-suppressive miRNAs is involved in CORO2A overexpression. Elucidation of the interaction between genes and miRNAs will help reveal the molecular pathogenesis of OSCC.     

Expression of Cancer Stem Cell Markers EpCAM and CD90 Is Correlated with Anti- and Pro-Oncogenic EphA2 Signaling in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Additionally, the efficacy of targeted molecular therapies with multiple tyrosine kinase inhibitors is limited. In this study, we focused on the cellular signaling pathways common to diverse HCC cells and used quantitative reverse phase protein array (RPPA) and statistical analyses to elucidate the molecular mechanisms determining its malignancy. We examined the heterogeneity of 17 liver cancer cell lines by performing cluster analysis of their expression of CD90 and EpCAM cancer stem cell markers. Gaussian mixture model clustering identified three dominant clusters: CD90-positive and EpCAM-negative (CD90+), EpCAM-positive and CD90-negative (EpCAM+) and EpCAM-negative and CD90-negative (Neutral). A multivariate analysis by partial least squares revealed that the former two cell populations showed distinct patterns of protein expression and phosphorylation in the EGFR and EphA2 signaling pathways. The CD90+ cells exhibited higher abundance of AKT, EphA2 and its phosphorylated form at Ser⁸⁹⁷, whereas the EpCAM+ cells exhibited higher abundance of ERK, RSK and its phosphorylated form. This demonstrates that pro-oncogenic, ligand-independent EphA2 signaling plays a dominant role in CD90+ cells with higher motility and metastatic activity than EpCAM+ cells. We also showed that an AKT inhibitor reduced the proliferation and survival of CD90+ cells but did not affect those of EpCAM+ cells. Taken together, our results suggest that AKT activation may be a key pro-oncogenic regulator in HCC.     

Combined Replenishment of miR‐34a and let‐7b by Targeted Nanoparticles Inhibits Tumor Growth in Neuroblastoma Preclinical Models

Neuroblastoma (NB) tumor substantially contributes to childhood cancer mortality. The design of novel drugs targeted to specific molecular alterations becomes mandatory, especially for high‐risk patients burdened by chemoresistant relapse. The dysregulated expression of MYCN, ALK, and LIN28B and the diminished levels of miR‐34a and let‐7b are oncogenic in NB. Due to the ability of miRNA‐mimics to recover the tumor suppression functions of miRNAs underexpressed into cancer cells, safe and efficient nanocarriers selectively targeted to NB cells and tested in clinically relevant mouse models are developed. The technology exploits the nucleic acids negative charges to build coated‐cationic liposomes, then functionalized with antibodies against GD₂ receptor. The replenishment of miR‐34a and let‐7b by NB‐targeted nanoparticles, individually and more powerfully in combination, significantly reduces cell division, proliferation, neoangiogenesis, tumor growth and burden, and induces apoptosis in orthotopic xenografts and improves mice survival in pseudometastatic models. These functional effects highlight a cooperative down‐modulation of MYCN and its down‐stream targets, ALK and LIN28B, exerted by miR‐34a and let‐7b that reactivate regulatory networks leading to a favorable therapeutic response. These findings demonstrate a promising therapeutic efficacy of miR‐34a and let‐7b combined replacement and support its clinical application as adjuvant therapy for high‐risk NB patients.     

Design and Investigation of Pd–C Eutectic Fixed-Point Cells for Thermocouple Calibration at NMIA

The calibration of Pt/Rh thermocouples up to 1560 \(^{\circ }\hbox {C}\) at NMIA currently uses the conventional ‘melt-wire technique’ to realize Gold (Au) and Palladium (Pd) melting points, resulting in the loss of 20 mm of wire from the junction end for each calibration. To avoid this loss, NMIA intends to replace the melt-wire technique with the use of miniature fixed-point cells. NMIA has established Copper (Cu) and Cobalt–Carbon (Co–C) eutectic cells for calibration of thermocouples to 1324 \(^{\circ }\hbox {C}\). To extend the calibration up to 1500 \(^{\circ }\hbox {C}\), miniature Palladium–Carbon (Pd–C) eutectic cells (1492 \(^{\circ }\hbox {C}\)) have been constructed and tested in collaboration with NMIJ, AIST. Although these cells are made of high-purity reference materials, careful consideration must be given to contamination introduced during the manufacture and filling of the crucibles and by their long-term use. These issues can only be assessed by measurement of cell-to-cell temperature differences within the ensemble of cells traceable to ITS-90. In the work presented here, 3 NMIA-design mini Pd–C cells were constructed: 1 at NMIA and 2 at NMIJ. These cells were compared, together with a “large” NMIJ Pd–C cell, using type-R, type-B and Pt/Pd thermocouples and radiation thermometry. Although the cells are found to be stable and repeatable, significant problems arising from migration of Pd to the thermocouples were identified.     

Self-organizable panel for assembling DIY ubiquitous computing

This paper proposes the concept of DIY (do-it-yourself) ubiquitous computing, an architecture allowing non-experts to establish ubiquitous computing environments in the real world. This concept has been implemented in the “u-Texture”, which is a self-organizable panel that works as a building block. While the traditional scheme attaches devices such as computers, sensors, and network equipments externally to make everyday objects smart, the u-Texture has these devices built in beforehand to assemble smart objects. The u-Texture can change its own behavior autonomously through recognition of its location, its angle of inclination, and surrounding environment by assembling these factors physically. This paper describes the design, the implementation, and various applications of u-Textures to confirm that the concept can contribute to establishment of ubiquitous computing environments in the real world without expert users.