This study aims to examine users' knowledge change characteristics and knowledge change process, and examined factors that may influence users' knowledge change process. A user search experiment was conducted, in which participants were asked to search for two learning‐related search tasks and use a mind‐map to organize their thoughts during the search process. Pre‐ and post‐search questionnaires were distributed to collect users' self‐assessed topic familiarity and task difficulty. Besides the overall knowledge change process by all the users, we identified four types of knowledge change styles using a hierarchical clustering method: Early knowledge change, Medium‐term knowledge change, Late knowledge change and Average knowledge change. In addition, we found that task type, task difficulty in information integration and difficulty in drawing the mind‐map had significant influences on users' knowledge change styles. This study took a process perspective to characterize users' knowledge change at different stages and shed light on when and how learning occurs during the search process.

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This study explored user interactions when accomplishing learning related tasks from a new perspective, the process perspective, and examined three main types of user interactions: searching, reading and writing behaviors. The goal is to characterize how users' searching, reading, and writing interactions change at different stages, and explore what contextual factors are related to the task completion process. A user experiment with thirty‐two participants was conducted, and each participant was asked to work on two types of learning tasks: receptive tasks and critical tasks. For data analysis, we calculated the percentage of searching time, reading time and writing time during four stages, to characterize users' task completion process. Our results demonstrated that users' reading efforts were evenly distributed at four stages; half of their searching efforts were devoted at the first stage and writing efforts were mainly spent at the last stage. In addition, we also found task type and users' cognitive style had significant effects on users' searching, reading, writing process, and their writing efforts in the first stage were correlated to the quality of learning outcome. This study took the process perspective to characterize user interactions at different stages, and this perspective provides us a more comprehensive picture of user interactions and has implications for the design of search systems to fully support user interactions and their task completion process.

Supramolecular chemotherapy is a strategy that is currently used to improve the therapeutic efficacy of traditional chemotherapy while mitigating side effects. Heptaplatin, a platinum chemotherapeutic antitumor drug in colorectal tumors, is traditionally used in the clinic. However, its side effects and low efficiency in killing tumors remain unresolved. Herein, a facile supramolecular chemotherapy platform on account of the host–guest chemistry between cucurbit[7]­uril and the commercially available heptaplatin was studied. At pH 7.4, heptaplatin showed a strong binding to the cucurbit[7]­uril nanocarrier by 1H NMR, whose K a was (1.38 ± 0.06) × 106 M–1 by isothermal titration calorimetry (ITC). At pH 6.0 in a tumor microenvironment, overexpressed spermine can exchange competitively heptaplatin from heptaplatin-CB[7]. This supramolecular complex achieved higher antitumor activity on colorectal tumor cells and lower cytotoxicity than the drug alone on colorectal normal cells. Furthermore, the antitumor mechanisms of supramolecular complex were investigated by apoptosis, cell cycle, and spermine synthase. It was found that heptaplatin-CB[7] consumed more colorectal tumorous intracellular spermine by the spermine synthase assay (413.85 ± 0.004 pg/mL); hepataplatin-CB[7] caused early apoptosis (87.73%) of colorectal tumor cells; heptaplatin-CB[7] induced an inhibitory response in the G1 phase of the tumor cell cycle. These findings demonstrated that heptaplatin-CB[7] had higher antitumor activity toward human colorectal tumor cells but lower cytotoxicity toward human colorectal normal cells. It is expected to promote the supramolecular chemotherapy and translational development of the nanocomplex into the clinical field.

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