In an attempt to overcome the cytotoxicity problem of the glutaraldehyde-fixed tissues, a naturally occurring crosslinking agent (genipin) was used by our group to fix biological tissues. The study was intended to investigate the rate of tissue fixation by genipin. Glutaraldehyde was used as a control. In addition, the degrees of tissue fixation by genipin at different pHs (pH 4.0, pH 7. 4, pH 8.5, or pH 10.5), temperatures (4 degrees C, 25 degrees C, 37 degrees C, or 45 degrees C), and initial fixative concentrations (0.250%, 0.625%, or 1.000%) were examined. The results obtained revealed that the rate of tissue fixation by glutaraldehyde was significantly faster than that by genipin. The degree of tissue fixation by genipin may be controlled by adjusting its fixation duration or fixation conditions. The order in degree of tissue fixation by genipin at different pHs, from high to low, was: at nearly neutral pH (pH 7.4 or pH 8.5) > at basic pH (pH 10.5) > at acidic pH (pH 4.0). The degrees of tissue fixation by genipin at different temperatures were about the same, except for that at 4 degrees C. In contrast, the initial fixative concentration did not seem to affect the degree of tissue fixation by genipin, if only the amount of genipin in the fixation solution was sufficient to complete tissue fixation. The concentrations of genipin in the aqueous solutions at different pHs, temperatures, and initial fixative concentrations tended to decrease with time with or without the occurrence of tissue fixation. This indicated that genipin was not stable in the aqueous solution. The instability of aqueous genipin was more remarkable with increasing pH or temperature. The results obtained in this study may be used to optimize the fixation process for developing bioprostheses fixed by genipin.
Recently, ionic liquids were verified to be combustible instead of nonflammable; the contrary was thought to be true due their extremely low vapor pressure. Flash point is one of the most important variables used to characterize the fire and explosion hazards of liquids. Because of extremely low vapor pressure and decomposition at elevated temperatures, the reason for ionic liquids to be combustible should be different from that of traditionally defined liquids. The flash point of ionic liquids in relation to their decomposition was investigated in this study by the estimation of vapor pressure and by use of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and flash point analyzer apparatus. The ionic liquids 1-ethyl-3-methylimidazolium ethylsulfate () and 1-butyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][NTf 2 ]), were selected as test examples. Results revealed that the flammability of ionic liquids was mainly attributed to the decomposition of the ionic liquids generating flammable substances instead of themselves vaporizing, as do traditionally defined combustible/flammable liquids. Lyon's method, applied by Fox et al. to estimate the flash point of ionic liquids from the TGA decomposition temperature, was assessed using our experimental data and the data from the published literature and resulted in substantial overestimation of the flash-point values of ionic liquids, which underestimates the fire and explosion hazards of ionic liquids. This deviation is attributed to flash-point values of ionic liquids located in the second temperature range of the TGA tracing, rather than in the third analogue, as predicted by Lyon's method.
Legal recognition of same-sex partnerships and marriages has been at the forefront of media attention in East Asian societies. For our comparative study, we carried out qualitative in-depth interviews with 31 gay men and lesbians to investigate the nuanced understanding of marriage, family and sexual citizenship within the context of debates on marriage equality across Hong Kong, Japan and Taiwan. Expanding on the theoretical concepts in Chen’s ‘Asia as method’, Iwabuchi’s ‘inter-Asian referencing’ and Yue and Leung’s ‘queer Asia as method’, we aim to understand how the act of marriage is defined, conducted and rationalized amidst a web of social relations within each research locale. We argue that despite the variations in the structure and practice of kin relations, same-sex unions cannot be detached from the kinship institution in the three research sites. Our study points to a different perspective on same-sex marriage that goes beyond the binary of assimilation to/dismantling of the heterosexual marriage institution by attending to the structural and symbolic significance of the family and community.
A naturally occurring crosslinking agent, genipin, extracted from the fruits of Gardenia jasminoides ELLIS was used by our group to chemically modified biomolecules. Genipin and its related iridoid glucosides have been widely used as an antiphlogistic and cholagogue in herbal medicine. Our previous study showed that the cytotoxicity of genipin is significantly lower than glutaraldehyde. The study was to investigate the feasibility of using genipin to polymerize hemoglobin as a blood substitute. The results indicated that the rate of hemoglobin polymerization by glutaraldehyde was significantly faster than that by genipin and it readily produced polymers with molecular masses greater than 500,000 Da. It was found that the maximum degree of hemoglobin polymerization by genipin was approximately 40% if over-polymerization is to be prevented. With increasing the reaction temperature, hemoglobin concentration, and genipin-to-hemoglobin molar ratio, the duration taken to achieve the maximum degree of hemoglobin polymerization by genipin became significantly shorter. The P50 value of the unmodified hemoglobin was 9 mmHg, while that of the genipin-polymerized PLP-hemoglobin increased to 21 mmHg. It was found in a rat model that the genipin-polymerized PLP-hemoglobin resulted in a longer circulation time than the unmodified hemoglobin. In conclusion, the results of the study indicated that the genipin-polymerized hemoglobin solution has a lower oxygen affinity and a longer vascular retention time than the unmodified hemoglobin solution.
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