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With the emergence of high technologies, there is a constant need for facilitating the changes in our lives. Among them, the online platform economy has been growing remarkably for a decade. This paradigm created a new labor market suggested several alternative work arrangements because it mediated works that are very attractive to those who want to use their free time to make money. In the nearly two years since the beginning of the COVID-19 pandemic in China, online platform workers also experienced changes due to the COVID-19 pandemic. Those who advocate for online work claim that it provides career opportunities by providing resources like greater work autonomy and a high potential for work–nonwork integration, resulting in more boundaryless, individualized, and whole life careers. All these factors led us to consider how we work, what we value in our workplace, and what motivates us. Among them, motivation is one of the key roles of management because it leads to and sustains behavior. However, prior studies have focused on the theoretical description of platform work motivation, and little is known about motivation causality from a behavioral perspective. This study aims to identify what leads people to become involved in online platform work. In detail. this research examined survey results related to what makes workers dominant in the platform labor market and attempted to explain all the previous phenomena based on the background of self-determination theory. [ABSTRACT FROM AUTHOR]

In this study we isolate a heptameric peptide from the marine microalga Pavlova lutheri and examine its inhibitory effect and mechanism of action on the matrix metalloproteinase-9 (MMP-9) protein in human fibrosarcoma HT1080 cells. Through consecutive rounds of purification we isolated a potent MMP-9 inhibitory peptide composed of seven amino acids: Leu-Leu-Ala-Pro-Pro-Glu-Arg (796.4 Da). We show that the mRNA and protein expression levels of MMP-9 are reduced in the presence of this purified peptide. Furthermore, we show that this peptide inhibits PMA-induced translocation of nuclear factor-κB (NF-κB) by suppressing IκB-α phosphorylation and that it suppresses the phosphorylation of the c-Jun N-terminal (JNK) and p38 mitogen-activated protein kinases (MAPKs). Our results indicate that this peptide, purified from P. lutheri, has the potential to be a valuable natural preventive agent against MMP-related diseases. [ABSTRACT FROM AUTHOR]

Microfluidic devices where the microchannel walls were decorated with micro and nanostructures were fabricated using 3D nanomolding. Using 3D molded microfluidic devices with microchannel walls decorated with microscale gratings, the fluid mixing behavior was investigated through experiments and numerical simulation. The use of microscale gratings in the micromixer was predicated by the fact that large obstacles in a microchannel enhances the mixing performance. Slanted ratchet gratings on the channel walls resulted in a helical flow along the microchannel, thus increasing the interfacial area between fluids and cutting down the diffusion length. Increasing the number of walls decorated with continuous ratchet gratings intensified the strength of the helical flow, enhancing mixing further. When ratchet gratings on the surface of the top cover plate were aligned in a direction to break the continuity of gratings from the other three walls, a stack of two helical flows was formed one above each other. This work concludes that the 3D nanomolding process can be a cost-effective tool for scaling-up the fabrication of microfluidic mixers with improved mixing efficiencies. [ABSTRACT FROM AUTHOR]

This study addresses gas-liquid two-phase flows in polymer (PMMA) micro-channels with non-molecularly smooth and poorly wetting walls (typical contact angle of 65°) unlike previous studies conducted on highly wetting molecularly smooth materials (e.g., glass/silicon). Four fundamentally different topological flow regimes (Capillary Bubbly, Segmented, Annular, Dry) were identified along with two transitory ones (Segmented/Annular, Annular/Dry) and regime boundaries were identified from the two different test chips. The regime transition boundaries were influenced by the geometry of the two-phase injection, the aspect ratio of the test micro-channels, and potentially the chip material as evidenced from comparisons with the results of previous studies. Three principal Segmented flow sub-regimes (1, 2, and 3) were identified on the basis of quantified topological characteristics, each closely correlated with two-phase flow pressure drop trends. Irregularity of the Segmented regimes and related influencing factors were addressed and discussed. The average bubble length associated with the Segmented flows scaled approximately with a power law of the liquid volumetric flow ratio, which depends on aspect ratio, liquid superficial velocity, and the injection system. A simplified semi-empirical geometric model of gas bubble and liquid plug volumes provided good estimates of liquid plug length for most of the segmented regime cases and for all test-channel aspect ratios. The two-phase flow pressure drop was measured for the square test channels. Each Segmented flow sub-regime was associated with different trends in the pressure drop scaled by the viscous scale. These trends were explained in terms of the quantified flow topology (measured gas bubble and liquid plug lengths) and the number of bubble/plug pairs. Significant quantitative differences were found between the two-phase pressure drop in the polymer micro-channels of this study and those obtained from previous glass/silicon micro-channel studies, indicating that the effect of wall surface properties is important. Pressure drop trends on the capillary scale along gas bubbles extracted from the measurements in square micro-channels indicated a linear dependence on the Capillary number and did not agree with those predicted by highly idealized theory primarily because explicit and implicit assumptions in the theory were not relevant to practical conditions in this study. [ABSTRACT FROM AUTHOR]