Lessons for museums from the pandemic lockdown: exploring user engagement with art museums in London on Facebook

Due to the unexpected COVID-19 pandemic, many institutions, such as museums, had been required to close so as to reduce non-essential human mobility. The dilemma of maintaining a consistent relationship with museums’ users emerged. What are the digital initiatives that museums had developed? How did user engagement change during the lockdown? Most importantly, what can be learnt from these practices for developing more effective engagement strategies after the pandemic? With basic statistical analysis and content analysis as the main research methods, this study examines how London art museums used Facebook during lockdown and the changes of corresponding user engagement behaviours. Specifically, three London-based art museums are chosen for this study, which are the National Gallery, Tate and the Victoria and Albert Museum (V&A). The results show that, during the period of lockdown, all three museums adjust their Facebook strategies in terms of both post type and content. The increase in the level of user engagement also suggests the effectiveness of some strategies, such as the frequency of museum posts and creation of different types of post content. These findings give reflections on art museums’ digital initiatives and contributed to the understanding of the museum online users

Facile Fabrication of Tumor Redox-Sensitive Nanoassemblies of Small-Molecule Oleate Prodrug as Potent Chemotherapeutic Nanomedicine

The conjugate of paclitaxel (PTX) and docosahexaenoic acid has entered into clinical trials. However, the most recent clinical outcomes fell short of expectations, due to the extremely slow drug release from the hydrophobic conjugates. Herein, a novel prodrug-based nanoplatform self-assembled by the disulfide bond linked conjugates of PTX and oleic acid for rapid and differential release of PTX in tumor cells is reported. This redox-responsive prodrug-nanosystem demonstrates multiple therapeutic advantages, including one-step facile fabrication, high drug-loading efficiency (56%, w/w), on-demand drug release responding to redox stimuli, as well as favorable cellular uptake and biodistribution. These advantages result in significantly enhanced antitumor efficacy in vivo, with the tumor almost completely disappearing in mice. Such a uniquely engineered prodrug-nanosystem has great potential to be used as potent chemotherapeutic nanomedicine in clinical cancer therapy

CFD: a collaborative feature difference method for spontaneous micro-expression spotting

Micro-expression (ME) is a special type of human expression which can reveal the real emotion that people want to conceal. Spontaneous ME (SME) spotting is to identify the subsequences containing SMEs from a long facial video. The study of SME spotting has a significant importance, but is also very challenging due to the fact that in real-world scenarios, SMEs may occur along with normal facial expressions and other prominent motions such as head movements. In this paper, we improve a state-of-the-art SME spotting method called feature difference analysis (FD) in the following two aspects. First, FD relies on a partitioning of facial area into uniform regions of interest (ROIs) and computing features of a selected sequence. We propose a novel evaluation method by utilizing the Fisher linear discriminant to assign a weight for each ROI, leading to more semantically meaningful ROIs. Second, FD only considers two features (LBP and HOOF) independently. We introduce a state-of-the-art MDMO feature into FD and propose a simple yet efficient collaborative strategy to work with two complementary features, i.e., LBP characterizing texture information and MDMO characterizing motion information. We call our improved FD method collaborative feature difference (CFD). Experimental results on two well-established SME datasets SMIC-E and CASME II show that CFD significantly improves the performance of the original FD

Nitrogen-enriched and hierarchically porous carbon macro-spheres-ideal for large-scale CO2 capture

A facile and efficient “spheridization” method is developed to produce nitrogen-enriched hierarchically porous carbon spheres of millimeters in diameter, with intricate micro-, meso- and macro-structural features. Such spheres not only show exceptional working capacity for CO2 sorption, but also satisfy practical requirements for dynamic flow in post-combustion CO2 capture. Those were achieved using co-polymerized acrylonitrile and acrylamide as the N-enriched carbon precursor, a solvent-exchange process to create hierarchically porous macro-sphere preforms, oxidization to induce cyclization of the polymer chains, and carbonization with concurrent chemical activation by KOH. The resulting carbon spheres show a relatively high CO2 uptake of 16.7 wt% under 1 bar of CO2 and, particularly, an exceptional uptake of 9.3 wt% under a CO2 partial pressure of 0.15 bar at 25 °C. Subsequent structural and chemical analyses suggest that the outstanding properties are due to highly developed microporous structures and the relatively high pyridinic nitrogen content inherited from the co-polymer precursor, incorporated within the hierarchical porous structures

Revealing silicon crystal defects by conductive atomic force microscope

The machining and polishing of silicon can damage its surface. Therefore, the investigation of the electric performance of the processed surface is of paramount importance for understanding and improving the utilization of silicon components with nanoscale crystal defects. In this study, conductivity of nanoscratches on the silicon surface was investigated using a conductive atomic force microscope. Compared to the original silicon surface (without any treatment), electrical breakover at low bias voltage could be detected on the mechanically scratched area of the silicon surface with crystal defects, and the current increased with the voltage. In contrast, no obvious current was found on the defect-free scratch created by tribochemical removal. The conductivity could also be observed on a friction-induced protrusive hillock created at high speed but not on a hillock created at low speed that is constructed by amorphous silicon. Further analysis showed that lattice distortions could facilitate easy electron flow and contributed significantly to the conductivity of a mechanical scratch on the silicon surface; however, the amorphous layer hardly contributed to the conductivity, which was also supported by high resolution transmission electron microscope analysis. As a result, the relationship between the electrical performance and microstructures was experimentally established. These findings shed new light on the subtle mechanism of defectdependent conductivity and also provide a rapid and nondestructive method for detecting surface defects

Preparation and Characterization of Stimuli-Responsive Magnetic Nanoparticles

In this work, the main attention was focused on the synthesis of stimuli-responsive magnetic nanoparticles (SR-MNPs) and the influence of glutathione concentration on its cleavage efficiency. Magnetic nanoparticles (MNPs) were first modified with activated pyridyldithio. Then, MNPs modified with activated pyridyldithio (MNPs-PDT) were conjugated with 2, 4-diamino-6-mercaptopyrimidine (DMP) to form SR-MNPs via stimuli-responsive disulfide linkage. Fourier transform infrared spectra (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize MNPs-PDT. The disulfide linkage can be cleaved by reduced glutathione (GHS). The concentration of glutathione plays an important role in controlling the cleaved efficiency. The optimum concentration of GHS to release DMP is in the millimolar range. These results had provided an important insight into the design of new MNPs for biomedicine applications, such as drug delivery and bio-separation

GmFT2a, a Soybean Homolog of FLOWERING LOCUS T, Is Involved in Flowering Transition and Maintenance

BACKGROUND: Flowering reversion can be induced in soybean (Glycine max L. Merr.), a typical short-day (SD) dicot, by switching from SD to long-day (LD) photoperiods. This process may involve florigen, putatively encoded by FLOWERING LOCUS T (FT) in Arabidopsis thaliana. However, little is known about the potential function of soybean FT homologs in flowering reversion. METHODS: A photoperiod-responsive FT homologue GmFT (renamed as GmFT2a hereafter) was cloned from the photoperiod-sensitive cultivar Zigongdongdou. GmFT2a gene expression under different photoperiods was analyzed by real-time quantitative PCR. In situ hybridization showed direct evidence for its expression during flowering-related processes. GmFT2a was shown to promote flowering using transgenic studies in Arabidopsis and soybean. The effects of photoperiod and temperature on GmFT2a expression were also analyzed in two cultivars with different photoperiod-sensitivities. RESULTS: GmFT2a expression is regulated by photoperiod. Analyses of GmFT2a transcripts revealed a strong correlation between GmFT2a expression and flowering maintenance. GmFT2a transcripts were observed continuously within the vascular tissue up to the shoot apex during flowering. By contrast, transcripts decreased to undetectable levels during flowering reversion. In grafting experiments, the early-flowering, photoperiod-insensitive stock Heihe27 promotes the appearance of GmFT2a transcripts in the shoot apex of scion Zigongdongdou under noninductive LD conditions. The photothermal effects of GmFT2a expression diversity in cultivars with different photoperiod-sensitivities and a hypothesis is proposed. CONCLUSION: GmFT2a expression is associated with flowering induction and maintenance. Therefore, GmFT2a is a potential target gene for soybean breeding, with the aim of increasing geographic adaptation of this crop