Microfluidic device fabricated by three‐dimensional lithography for observation of cancer cell invasion process

This paper describes a microfluidic device for observation of cancer cell invasion induced by chemotaxis. The developed device has two main channels, the channel filled with cell suspension and the channel filled with solution containing chemotactic factor. These channels are connected via tapered orifice structures to capture multiple cancer cells in it to form cell clusters. Observation of cell invasions affected by cell adhesions is possible with this device. The devices were fabricated by using three‐dimensional lithography and PDMS (polydimethylsiloxane) molding. Invasion cells leaving the cell clusters and moving to the channel containing chemotactic factors through the orifices were successfully observed on the device.     

Burning Characteristics of Ammonium Nitrate‐based Composite Propellants Supplemented with Ammonium Dichromate

Ammonium nitrate (AN)‐based composite propellants have attracted much attention, primarily because of the clean burning nature of AN as an oxidizer. However, such propellants have some disadvantages such as poor ignition and low burning rate. Ammonium dichromate (ADC) is used as a burning catalyst for AN‐based propellants; however, the effect of ADC on the burning characteristics has yet to be sufficiently delineated. The burning characteristics of AN/ADC propellants prepared with various contents of AN and ADC have been investigated in this study. The theoretical performance of an AN‐based propellant is improved by the addition of ADC. The increase in the burning rate is enhanced and the pressure deflagration limit (PDL) becomes lower with increasing amount of ADC added. The increasing ratio of the burning rate with respect to the amount of ADC is independent of the AN content and the combustion pressure. The optimal amount of ADC for improving the burning characteristics has been determined.     

Assessment of Optimal Power Generation Mix Considering Extensive Variable Renewable Energy and Nationwide Power Interchange through Tie Lines

This paper evaluates the optimal power generation mix considering massive deployment of variable renewable energy and regional power interchange. Japan has initiated the feed‐in‐tariff (FIT) and expected the significant introduction of PV and wind power for energy self‐sufficiency and climate change. However, wind power resources in Japan are concentrated mainly in Hokkaido and the Tohoku region, which are remote from electricity‐consuming areas such as Tokyo, and facilitating the considerable deployment of wind power requires the establishment of inter‐regional power transmission lines. Against these backgrounds, we develop an optimal power generation mix model including regional electricity exchange as a large‐scale linear programming model with 10 million variables and 30 million constraints. The calculation results show that regional grid expansion encourages wind power installation in the Hokkaido and Tohoku regions for power supply to the Tokyo area, where PV power and stationary batteries are alternatively replaced. Grid expansion too promotes the shift of PV installation to the Kyushu and Shikoku regions, which have longer sunshine duration, and interchangeably mitigates PV deployment in other regions through the transport of PV power from those two regions.     

Display Method for Online Bookstore Emulating Real Bookstore by WebGL

Thanks to the spread of the Internet, opportunities to use online bookstores have been increasing in recent years. However, it is difficult for the typical customer to intuitively grasp which book sells well or which book is recommended by the shop. We have therefore developed a display system for virtual bookstores in which an image of books arranged in a bookshelf or stacked on a table is reproduced by using WebGL. Since the amount of book stock that is managed by the server side needs to be changed as orders come in from clients, we introduce a server side technology using a hypertext preprocessor (PHP).     

EVALUATION OF LIQUID-LIQUID PARTITION COEFFICIENTS OF MULTTDENTATE AMINES BY SCALED PARTICLE THEORY

ABSTRACT

For some aliphatic and aromatic bidentate amines, e.g., ethylenedi-amine derivatives, which were used in the synergistic extraction system, the liquid-liquid partition coefficients (P) were measured between benzene and water phases and discussed together with other aliphatic and aromatic multidentate amines by using the scaled particle theory (SPT). The contributions of three kinds of Gibbs energies, i.e, the cavity formation energy (G¯_h), the dispersion energy (G¯_dis) and hydrogen-bonding energy (G¯_h), to the P values were successfully evaluated. The main factor to determine the P value was G¯_h (10–55 kJ/mol) in the aqueous phase, but the contributions of G¯_c (6–15 kJ/mol) and G¯_dis (6–28 kJ/mol) were not negligibly small.     

Synergistic Effect of Bolus Exposure to Zinc Oxide Nanoparticles on Bleomycin-Induced Secretion of Pro-Fibrotic Cytokines without Lasting Fibrotic Changes in Murine Lungs

Zinc oxide (ZnO) nanoparticles are widely used in various products, and the safety evaluation of this manufactured material is important. The present study investigated the inflammatory and fibrotic effects of pulmonary exposure to ZnO nanoparticles in a mouse model of pulmonary fibrosis. Pulmonary fibrosis was induced by constant subcutaneous infusion of bleomycin (BLM). Female C57BL/6Jcl mice were divided into BLM-treated and non-treated groups. In each treatment group, 0, 10, 20 or 30 µg of ZnO nanoparticles were delivered into the lungs through pharyngeal aspiration. Bronchoalveolar lavage fluid (BALF) and the lungs were sampled at Day 10 or 14 after administration. Pulmonary exposure by a single bolus of ZnO nanoparticles resulted in severe, but transient inflammatory infiltration and thickening of the alveolar septa in the lungs, along with the increase of total and differential cell counts in BLAF. The BALF level of interleukin (IL)-1β and transforming growth factor (TGF)-β was increased at Day 10 and 14, respectively. At Day 10, the synergistic effect of BLM and ZnO exposure was detected on IL-1β and monocyte chemotactic protein (MCP)-1 in BALF. The present study demonstrated the synergistic effect of pulmonary exposure to ZnO nanoparticles and subcutaneous infusion of BLM on the secretion of pro-fibrotic cytokines in the lungs.     

Suppressive effect of Tetragenococcus halophilus,isolated from fish-nukazuke,on histamine accumulation in salted and fermented fish

Occasionally, quantities higher than 1000 mg/kg of histamine (Hm) accumulate in salted and fermented fish products by the histidine decarboxylase of halophilic lactococci Tetragenococcus sp. In a total of 200 isolates from fish nukazuke (salted and fermented fish with rice bran), 13 strains produced Hm more than 200 μg/ml in 0.5% histidine containing broth, whereas 130 isolates produced absolutely no Hm. Among the strains, 22 strains suppressed the Hm production of the Hm-forming (HmF) strains. Both the HmF and Hm-suppressing (HmS) strains were identified as Tetragenococcus halophilus. To observe the Hm-suppressing effect, a specified quantity of live cells was needed. In the case of 10% NaCl salted sardine, inoculation with 3 log cells/g of a strain HmF-131 resulted in a significant Hm accumulation, 2800 μg/g in 30 days at 20 °C. The increase in Hm was clearly suppressed by 9 log live cells/g of strain HmS-129. These results suggest that HmS-129 can be used as a starter for salted and fermented fish products, enhancing food safety.     

Identification of a novel food-derived collagen peptide,hydroxyprolyl-glycine,in human peripheral blood by pre-column derivatisation with phenyl isothiocyanate

Peptides in the blood of subjects before and after collagen hydrolysate ingestion were fractionated by ion exchange and size-exclusion chromatographies and then derivatised with phenyl isothiocyanate. The derivatives were characterised by reserved phase (RP)-HPLC. Prolyl-hydroxyproline (Pro-Hyp), which has been identified in the previous studies, was detected as a major food-derived collagen peptide in the blood of all subjects (n = 5). Another major peptide was identified as hydroxyprolyl-glycine (Hyp-Gly) in the blood of four subjects, which has not been detected in previous studies. The ratio of Hyp-Gly to Pro-Hyp depended on subjects and ranged from 0.00 to 5.04. Hyp-Gly was less susceptible to human serum peptidase than Pro-Hyp. Hyp-Gly enhanced the growth of mouse primary fibroblasts on collagen gels in a higher extent than Pro-Hyp. These findings suggest that Hyp-Gly plays a significant role in exerting the biological effects by ingestion of collagen hydrolysate.     

Establishment of a Rapid Detection System for ISG20-Dependent SARS-CoV-2 Subreplicon RNA Degradation Induced by Interferon-α

Inhaled nebulized interferon (IFN)-α and IFN-β have been shown to be effective in the management of coronavirus disease 2019 (COVID-19). We aimed to construct a virus-free rapid detection system for high-throughput screening of IFN-like compounds that induce viral RNA degradation and suppress the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We prepared a SARS-CoV-2 subreplicon RNA expression vector which contained the SARS-CoV-2 5′-UTR, the partial sequence of ORF1a, luciferase, nucleocapsid, ORF10, and 3′-UTR under the control of the cytomegalovirus promoter. The expression vector was transfected into Calu-3 cells and treated with IFN-α and the IFNAR2 agonist CDM-3008 (RO8191) for 3 days. SARS-CoV-2 subreplicon RNA degradation was subsequently evaluated based on luciferase levels. IFN-α and CDM-3008 suppressed SARS-CoV-2 subreplicon RNA in a dose-dependent manner, with IC50 values of 193 IU/mL and 2.54 μM, respectively. HeLa cells stably expressing SARS-CoV-2 subreplicon RNA were prepared and treated with the IFN-α and pan-JAK inhibitor Pyridone 6 or siRNA-targeting ISG20. IFN-α activity was canceled with Pyridone 6. The knockdown of ISG20 partially canceled IFN-α activity. Collectively, we constructed a virus-free rapid detection system to measure SARS-CoV-2 RNA suppression. Our data suggest that the SARS-CoV-2 subreplicon RNA was degraded by IFN-α-induced ISG20 exonuclease activity.