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The Nature of Science (NOS) is an important component of scientific literacy. Science teachers' Views of the Nature of Science (VNOS) directly affect their teaching behaviors. Therefore, it is of great significance to explore science teachers' VNOS and find ways of improvement. This study was designed to comparatively investigate preservice science teachers' VNOS between China and Canada. The study employed a survey design to explore how Chinese and Canadian preservice science teachers understood the seven different aspects of NOS. Data showed that preservice science teachers in China and Canada both hold a modern view about science education. The level of Chinese and Canadian participants' understanding of NOS was above the relatively naive level. Chinese teachers had better macro-understanding toward science education, but their micro-mastery was insufficient. The Canadian participants had a better understanding of the NOS than their Chinese counterparts. The study suggested that there is a need to reconstruct the preservice science teacher education curriculum in China and promote the transformation in the science teacher educational system.

Purpose: The Canadian university where this study took place has established an international exchange program in teacher education with a large Chinese university. This study was designed to examine how the international exchange program influenced Chinese science teacher candidates' understanding of science education and how such learning impacted their teaching in China. Design/Approach/Methods: The study adopted a qualitative research design with interview and reflective journal as the main approaches for data collection. Findings: Participants greatly appreciated the opportunity of exchange. They reported an improved understanding of Canadian school education and its science curriculum and pedagogy, which changed many aspects of their original values about the relationship between the teacher and students, classroom environment, and so on. Although they faced many constraints to implement what they learned from the exchange in Chinese science classrooms, what they learned had never been forgotten. Participants tried to apply them here and there at the level they could control. Originality/Value: There are many reported studies in the literature about Chinese international students on Western campuses. However, research on Chinese students who participate in international exchange programs is very rare. The findings of this study can inform policymakers and education practitioners about student international exchange programs and benefit future exchange participants.

Silicon photonics with the advantages of low power consumption and low fabrication cost is a crucial technology for facilitating high-capacity optical communications and interconnects. The graphene photodetectors (GPDs) featuring broadband operation, high speed, and low integration cost can be good additions to the SiGe photodetectors, supporting high-speed photodetection in wavelength bands beyond 1.6 μm on silicon. Here we realize a silicon-integrated four-channel wavelength division multiplexing (WDM) optical receiver based on a micro-ring resonator (MRR) array and four p-n homojunction GPDs. These photo-thermoelectric (PTE) GPDs exhibit zero-bias responsivities of ∼1.1 V W−1 and set-up limited 3 dB-bandwidth >67 GHz. The GPDs show good consistence benefiting from the compact active region array (0.006 mm2) covered by a single mechanically exfoliated hBN/graphene/hBN stack. Moreover, the WDM graphene optical receiver realized 4 × 16 Gbps non-return-to-zero optical signal transmission. To the best of our knowledge, it is the first GPD-array-based optical receiver using high-quality mechanically exfoliated graphene and edge graphene-metal contacts with low resistances. Apparently, our design is also compatible with CVD-grown graphene. This work sheds light on the large-scale integration of GPDs with high consistency and uniformity, enabling the application of high-quality mechanically exfoliated graphene, and promoting the development of the graphene photonic integrated circuits.

The 24 Nature Notes project was part of the China-Canada Reciprocal Learning Program. Two sister schools participated in the project. Following the same set of dates, students from both schools conducted outdoor observations and collected data. Skype meetings were arranged to exchange ideas and share student work. This study aims to understand the impact of the project on Canadian and Chinese teachers and students, what they learned from each other, and what challenges they faced. Data was collected through observation notes, meeting minutes, student work, and interviews with both Chinese and Canadian teachers and students. Data analysis revealed that the project was a positive opportunity for participants from both countries to gain cross-cultural understanding. The Canadian students enjoyed the freedom in topic selection and presentation formats. They particularly liked the life lessons that the Chinese students shared through their work. The Canadian teachers also valued the idea as it allows students to reflect their observations from a different context. The Chinese teachers and students appreciated the Canadian students' creativity. They gained inspiration from Canadian teachers and students and as a return their project work became more creative.

As part of the SSHRC partnership grant on Reciprocal Learning between Ontario, Canada and Southwest, China, we examined the commonalities and differences in secondary school Inquiry-based Teaching (IBT) in science between sister schools in Ontario, Canada and Southwest, China. Canadian and Chinese teachers' interpretations of inquiry through video-recorded lessons, qualitative observational annotations, and quantitative data collected via the EQUIP instrument were analyzed. Results suggest that there is a non-significant difference in application of IBT between secondary science teachers in Ontario, Canada and in Southwest, China between the reciprocal learning populations. Both populations are perceived to use inquiry-based teaching methods in their classrooms proficiently, and that students are more receptive at a higher cognitive level when teachers incorporate IBT.

Mid-infrared (MIR) silicon photonics have attracted great interest for potential applications in on-chip spectroscopy, free-space communication, and remote imaging. Currently, the high-performance and fabrication-friendly fiber-to-chip grating couplers operating at 3–4 μm wavelength band are still desired urgently. Here, we propose an efficient method for designing a 2D subwavelength grating coupler. The few analytical fitting parameters defining the subwavelength grating periods and fill factors in two dimensions enable a high design degree of freedom and a low search space dimension, resulting in high figure-of-merit and fast convergence simultaneously. The developed 3.7 μm grating coupler showcases record-high coupling efficiency both theoretically (−2.2 dB) and experimentally (−4.4 dB) among the 3–4 μm MIR counterparts. This study provides an effective method for designing fiber-to-chip grating couplers, by which the MIR grating couplers with high performance and fabrication ease are developed, thus paving the way for developing high-performance silicon photonic integrated circuits operating in the MIR wavelength band. [ABSTRACT FROM AUTHOR]

Bacillus probiotics have a sporulation capacity that makes them more suitable for processing and storage and for surviving passage through the gastrointestinal tract. The probiotic functions and regulatory mechanisms of different Bacillus have been exploited in many reports, but little is known about how various Bacillus probiotics perform different functions. This knowledge gap results in a lack of specificity in the selection and application of Bacillus. The probiotic properties are strain-specific and cell-type-specific, and are related to the germination potential and to the diversity of metabolites produced following intestinal germination, as this causes the variation in probiotic function and mechanisms. In this review, we discuss the Bacillus metabolites produced during germination and sporulation in the GI tract, as well as possible processes affecting intestinal homeostasis. We conclude that the oxygen-capturing capability and the production of antimicrobials, exoenzymes, competence and sporulation factors (CSF), exopolysaccharides, lactic acid, and cell components are specifically associated with the functional mechanisms of probiotic Bacillus. The aim of this review is to guide the screening of potential Bacillus strains for probiotics and their application in nutrition research. The information provided will also promote further research on Bacillus-derived functional metabolites in human nutrition. [ABSTRACT FROM AUTHOR]

This study used the Generalized Anxiety Disorder (GAD-7) and 9 Patients Health Questionnaire (PHQ-9) to investigate the anxiety and depression of 1366 primary school students in Shenzhen after the resumption of school. Following the COVID-19 pandemic, many parents began wondering whether months of isolation, a lack of organized school education, and potential loss of relatives would have a long-term impact on their children's mental health. The results of this study indicate that the rates of anxiety and depression among primary school students are indeed higher than before COVID-19, including the detection rate of anxiety and depression comorbidity, which has reached 11.7%. As age and grade increase, so do the scores of anxiety and depression among primary school students, with those of boys being higher than those of girls. In addition to age, grade, and gender, anxiety and depression scores were found to also be affected by other factors, such as the daily time spent using mobile phones for entertainment and exercising. Besides, these increases were found to be related to feelings of fear and nervousness towards aspects of the pandemic and worries about getting sick. Altogether, these results indicate that the mental state and health of primary school students following the pandemic is worth paying attention to, and that psychological intervention should be carried out in time. Overall, the results of this study may serve as a helpful guide as to how primary schools should carry out courses and activities to promote students' mental health after the pandemic situation stabilizes. Moreover, they may provide a reference for further study on the influence of pandemic situations on the anxiety and depression of primary school students. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide (TMDC) materials with excellent optoelectronic properties have attracted much attention in the fields of reconfigurable electronic devices, next-generation FETs, and photodetectors (PDs). While normal TMDC PDs have a bandgap-limited absorption edge of ∼1.3 µm, metal-TMDC Schottky PDs based on internal photoemission provide an operation band extension strategy. In this study, we demonstrate that a TMDC PD can even operate at the wavelength band as long as 2.0 µm by judiciously choosing TMDC and metal materials to construct a low barrier height Schottky PD. Specifically, a silicon waveguide-integrated Al-MoTe 2 Schottky PD was measured with responsivities of 18 mA/W and 5.5 mA/W at 1.6 µm and 2 µm, respectively. Meanwhile, the dark current is as low as 2 µA. The linear response can be maintained when the input optical power is in the mW scale. A measured 3 dB bandwidth is much larger than 1.75 MHz. These findings offer a promising avenue for expanding the detection range of the TMDC-based PDs with overall good performance in responsivity, bandwidth, sensitivity, and linearity.

Hydrogel scaffolds have numerous potential applications in the tissue engineering field. However, tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties. Inspired by Chinese ramen, we propose a universal fabricating method (printing-P, training-T, cross-linking-C, PTC & PCT) for tough hydrogel scaffolds to fill this gap. First, 3D printing fabricates a hydrogel scaffold with desired structures (P). Then, the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance (T). Finally, the training results are fixed by photo-cross-linking processing (C). The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa (622-fold untreated) and have excellent biocompatibility. Furthermore, this scaffold possesses functional surface structures from nanometer to micron to millimeter, which can efficiently induce directional cell growth. Interestingly, this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt, and many hydrogels, such as gelatin and silk, could be improved with PTC or PCT strategies. Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers, blood vessels, and nerves within 4 weeks, prompting the rapid regeneration of large-volume muscle loss injuries., (© 2024. The Author(s).)

Paeonia lutea is a wild peony (an endangered flowering plant species) found in China. Seed abortion (endosperm and embryo development failure) is linked to several endangered plant species. Therefore, it is of interest to complete a comparative analysis of transcriptome between the normal active seeds (Population A) and the endangered abortion seeds (Population H). Data from GO assignments of differentially expressed genes (DEGs) shows that "metabolic process", "binding", "cellular process", "catalytic activity", "cell" and "cell part" are commonly prevalent in these popuations. DEGs between the populations are found to be connected with metabolic pathways, biosynthesis of secondary metabolites, purine metabolism and ribosome. We used quantitative RT-PCR to validate 16 DEGs associated with these populations. It is found that histone genes and proline-rich extensin genes are predominant in the common groups. Histone genes (H2A, H2B, H3, H4 and linker histone H1) show 3 to 4 folds log2FC higher expession in population A than in population H in stage I unlike in stage II and III. Increased activity of proline-rich extensin genes in population A than in population H corresponding to seed abortion in the later population is implied. These preliminary data from the transcriptome analysis of the wild type plant species Paeonia lutea provide valuable insights on seed abortion., (© 2020 Biomedical Informatics.)