To assess applicability of the tactile sensor in hardness measurement of cultured cartilage and to clarify the relationship between hardness and tissue structure of cultured cartilage fabricated by the collagen-gel embedding method, we studied the effect of glycosaminoglycans on hardness of such cultured cartilage using a tactile sensor and electron probe x-ray microanalyzer (EPMA). Hardness measured by the tactile sensor, that is, change in frequency of naturally oscillating piezoelectric elements caused by contact with a testing material, increased with the number of days of culture or seeding cell density. Analysis of the sulfur component in EPMA results mainly reflected glycosaminoglycans produced by chondrocytes. Sulfur mapping indicated that tissue of the cultured cartilage differed between its surface and the inside; layers rich in glycosaminoglycans and cells had formed in the surface. Changes in frequency showed close correlation with the amount of glycosaminoglycans in the surface and the inside (r = 0.98 and 0.85, respectively) of cultured cartilage measured by EPMA. Thus, the tactile sensor is capable of measuring hardness of cultured cartilage, reflecting the change in tissue structure between the surface and the inside of the cartilage.

The cationic gadolinium metallocene [(C 5 Me 5 ) 2 Gd][B(C 6 F 5 ) 4 ], when combined with an excess amount of Al( i Bu) 3 , efficiently produces polyethylene at 80°C under 0.8 MPa pressure of ethylene. After quenching, the resulting polyethylene has ethyl group at one end and isobutyl group at the other terminal. Because no Gd-alkyl species appears to be involved, a mechanism with conventional coordinative chain transfer polymerization (CCTP) is not feasible. Density functional theory (DFT) analyses indicate a novel mechanism in which the cationic Gd plays a crucial role by coordinating ethylene and assists the insertion of the coordinated ethylene into AlÀ C bond.

Background Entamoeba histolytica infection is an increasingly common sexually transmitted infection in Japan. Currently, stool ova and parasite examination (O&P) is the only approved diagnostic method. Herein, we assessed the utility of the commercially available rapid antigen detection test (QUIK CHEK) for E. histolytica. Methods A multicenter cross-sectional study was conducted. Stool samples that had been submitted for O&P examination were included. The samples were subjected to both QUIK CHEK and polymerase chain reaction (PCR), and the QUIK CHEK results were assessed in comparison with PCR as the reference standard. Results E. histolytica infection was confirmed in 5.8% (38/657) of the samples and comprised 20 diarrheal and 18 non-diarrheal cases. The overall sensitivity and specificity of QUIK CHEK was 44.7% [95% confidence interval 30.1–60.3] and 99.8% [99.1–100], respectively. The sensitivity of QUIK CHEK was higher for diarrheal cases (60.0%) than non-diarrheal cases (27.8%). Further, the combined use of QUIK CHEK with O&P increased the sensitivity (78.9%), especially for diarrheal cases (up to 90%). The E. histolytica burden assessed by quantitative PCR was similar between QUIK CHEK-positive and -negative samples. The QUIK CHEK assay sensitivity was lower for cyst-containing stools than for trophozoite-containing stools, although it was shown that cultured E. histolytica clinical strains from QUIK CHEK-negative cyst-containing stools exhibited antigenicity in vitro. Conclusions The present study confirmed the high specificity of QUIK CHEK for E. histolytica infection. Combined use with O&P increased the sensitivity of detection, facilitating the use of QUIK CHEK in point-of-care settings in non-endemic situations.

A novel mechanism for the polymerization of butadiene by cationic gadolinium metallocene in the presence of excess Al(iBu)3 is presented. The absence of an initial Gd‐alkyl bond in this reaction system precludes the conventional mechanism by coordinative chain transfer polymerization (CCTP). Density functional theory (DFT) analysis indicates a mechanism in which cationic Gd assists butadiene insertion into one of the Al–C bonds of Al(iBu)3, explaining the 1,4‐cis selectivity unique to this catalytic system. More information can be found in the Research Article by Rika Fukushima et al.

The present study aimed to clarify the effects of soluble tannins from astringent persimmon on the qualities (color and texture) of Japanese wheat noodles (udon). We investigated the addition of the untreated paste or juice of astringent persimmon, which are abundant in soluble tannins and highly astringent, to flour during the production of Japanese noodles. The resulting noodles were dark in color and reddish. Also, the values of elasticity modulus and repture stress of boiled noodles were increased by the addition of the untreated astringent paste or juice from astringent persimmon. It is concluded that the qualities of udon noodles were highly influenced by the addition of soluble tannins from astringent persimmon.