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The demolding process in micro-injection molding constitutes a critical phase, exerting a decisive influence on the quality of polymer microstructures. In this study, the demolding forces of PMMA microfluidic chips were measured under different demolding temperatures, packing pressures, and demolding speeds by using pure nickel (Ni) mold insert. The dimensional deviations of the microchannels with different aspect ratios were analyzed. In addition, the effect of mold insert modification on the demolding force was further analyzed. The results showed that the effect of demolding temperature on the demolding force was the most significant, and the peak demolding force decreased with the decrease in temperature. The width of the microchannels increased and the depth decreased after demolding, while the opposite results were observed for the micro-mixing structures. However, the dimensional deviation of the micromixing structures was larger than that of the microchannels. Using the optimal molding parameters, the peak demolding force could be reduced from 114.0 N at 110[degrees]C to 47.0 N, a decrease of 58.8%. It is noteworthy that, when the microchannel was narrower than 100 [micro]m, achieving precise replication of microchannel dimensions became progressively more challenging as the microchannel width decreased. Using the Ni-W[S.sub.2] mold insert with low surface energy and low friction coefficient, the demolding force could be further reduced by 38.3%. The effect of the molding quality of microfluidic chip microstructures on the mixing performance of heavy metals was demonstrated by micro-mixing experiments. Highlights * Demolding temperature crucially affects microstructure dimensions. * Optimal parameters and modified mold insert reduce demolding force by 38.3%. * Dimensional deviation increases with the increase of microchannel aspect ratio. * Optimized microfluidic chip enhances [Co.sup.2+] chemiluminescence by 6.42%. KEYWORDS demolding force, dimensional deviation, microfluidic chip, micro-injection molding, microstructure, 1 | INTRODUCTION Microfluidics is extensively employed in various fields such as biotechnology, chemical analysis, and medical diagnosis. (1,2) Microfluidic chips, which integrate an array of microstructures including microchannels, microcolumns, [...]

The term “ wanghong women” has been in a state of flux in China’s public discourse since its inception in 2015. In particular, the COVID-19, while causing major economic setbacks across the world, has, to some extent, boosted the growth of the wanghong industry and altered public attitude towards wanghong women in China. Against this background, this study aims to investigate how wanghong women are linguistically represented in the six leading official English language newspapers in China. A corpus-assisted discourse analysis of 156 English news articles (i.e., 140,931 words), covering the years between 2015 and 2022, was conducted. The study revealed a significant attitudinal shift in the editorial stance on China’s wanghong women phenomenon since the COVID-19 epidemic: the semantic prosodies of the word “ wanghong ” has shifted from women who are stereotypically young, fashionable, and attract online attention by using pretty face and sexualized body shape to women who can boost the national digital economy, contribute to the state’s agenda of rural regeneration, and help spread timely instructions regarding the pandemic. The findings shed new light on the evolving Chinese gender politics which is shaped by the entangled forces of traditional patriarchy, commercialization, and the government’s crisis management strategies during the pandemic.

Objective To compare the performance of conventional and spectral flow cytometers in detecting auto-fluorescence samples. Methods Single cell samples with auto-fluorescence were prepared and stained by annexin V(AV)binding and propidium iodure (PI) to detect apoptosis. The same auto-fluorescence sample was run on conventional and spectral flow cytometers side by side. Results By avoid using FITC in conventional cytometers, the better result was gotten in detecting auto-fluorescence samples. Full spectrum cytometry presented better resolution even there was spectral overlap. It was easy to discriminate the signals derived from auto-fluorescence and FITC. The protocol of annexinV binding and PI staining to analyze apoptosis was optimized. Conclusions Spectral flow cytometry shows relatively excellent performance under certain conditions in detecting of apoptosis derived from auto-fluorescence samples.