Dynamic Thermosetting Resins with Synergistic Enhanced Strength and Toughness through Combination with Rigid and Soft Microdomains.

Preparation of materials that possess highly strong and tough properties simultaneously is a great challenge. Thermosetting resins as a type of widely used polymeric materials without synergistic strength and toughness limit their applications in some special fields. In this report, an effective strategy to prepare thermosetting resins with synergistic strength and toughness, is presented. In this method, the soft and rigid microspheres with dynamic hemiaminal bonds are fabricated first, followed by hot-pressing to crosslink at the interfaces. Specifically, the rigid or soft microspheres are prepared via precipitation polymerization. After hot-pressing, the resulting rigid-soft blending materials exhibit superior strength and toughness, simultaneously. As compared with the precursor rigid or soft materials, the toughness of the rigid-soft blending films (RSBFs) is improved to 240% and 2100%, respectively, while the strength is comparable to the rigid precursor. As compared with the traditional crushing, blending, and hot-pressing of rigid or soft materials to get the nonuniform materials, the strength and toughness of the RSBFs are improved to 168% and 255%, respectively. This approach holds significant promise for the fabrication of polymer thermosets with a unique combination of strength and toughness.

An X-ray activatable gold nanorod encapsulated liposome delivery system for mitochondria-targeted photodynamic therapy (PDT).

In this work, we developed a mitochondria-targeted nanomaterial for neoadjuvant X-ray-triggered photodynamic therapy of rectal cancer. Herein, we designed a biodegradable liposome incorporating a photosensitizer, verteporfin, to generate X-ray-induced reactive oxygen species, gold nanorods as radiation enhancers, and triphenylphosphonium as the mitochondrial targeting moiety. The average size of the nanocarrier was about 150 nm. Due to the synergetic effect between X-ray and a combination of verteporfin and gold nanorods, as well as precise site-targeted TPP-modified liposomal nanocarriers, our nanoconjugates generated sufficient cytotoxic singlet oxygen within the mitochondria under X-ray irradiation, triggering the loss of membrane potential and mitochondria-related apoptosis of cancer cells.

How do anxiety and stress impact the performance of Chinese doctoral students through self-regulated learning?-A multi-group analysis.

Introduction: Highly accomplished doctoral students may suffer when they cannot manage their performance due to the crippling effects of anxiety and stress. This is even more likely to occur in the highly charged setting of competitive research. Using a structural equation modeling approach, this study examined how anxiety and stress impact the performance of Chinese doctoral students through self-regulated learning. Methods: A total of 491 doctoral students and recent completers representing 112 universities in China participated in this study. A 42-item five-point Likert scale survey was used to measure participants' perceived anxiety (emotional and physical reactions), stress (study- and research-related stress), self-regulated learning, and performance (task and contextual performance) in their doctoral studies. Specifically, the extent to which participants' self-regulated learning mediated the influence of anxiety and stress on their task performance and contextual performance in their doctoral studies, as well as significant structural equation modeling differences across demographic variables of gender (i.e., male versus female), major (i.e., arts versus sciences), status (i.e., individuals pursuing a doctoral degree versus recent completers), and age (i.e., 30 and younger versus over 30) were examined. Results and Discussion: The results indicated that self-regulated learning considerably affected task and contextual performance; stress had a considerable direct effect on task and contextual performance; the indirect influence of stress on task and contextual performance via self-regulated learning was significant; and there was a significant structural equation modeling difference between arts and sciences doctoral students. Educational implications are discussed.

A mixed-methods national study investigating key challenges in learning English as a foreign language: A Chinese college student perspective.

Introduction: This mixed-methods national study has a two-fold purpose: (a) to invite Chinese college students to rate their overall difficulties in the eight areas of English learning, i.e., listening, speaking, reading, writing, pronunciation, grammar, vocabulary, and culture; and (b) to invite them to identify their key challenges in learning EFL. Specifically, the following three research questions were asked: (a) what are their overall difficulties in the eight areas of learning EFL? (b) Are there significant differences in rating their overall difficulties in these eight areas across the demographic variables of gender (i.e., male versus female participants) and subject discipline (arts versus sciences versus English subject disciplines participants)? And (c) what are their key challenges in learning EFL? Methods: The participants included a sample of 1,525 freshmen and sophomore students currently studying at seven universities across China. The instrument was a survey that consisted of a five-point Likert scale self-evaluation form and a major essay question addressing their key challenges. The qualitative data can help to probe deeply into the research setting to obtain in-depth understandings about Chinese college students' English learning; and therefore, they can greatly enhance the quantitative data. Results and discussion: The quantitative results indicated that listening, speaking, and writing were their three key difficult areas in EFL learning; further, students' subject discipline (arts versus sciences verse English subject disciplines) had significant effects on their perceived learning challenges in English listening and vocabulary. The qualitative results confirmed that listening, speaking, and writing were their three key challenging areas. Their specific learning challenges in each area were examined. Implications for Chinese college English teachers and administrators are discussed in terms of pedagogy and policy making, respectively.