What should constitute knowledge bases that we expect our future teachers to gain related to pedagogically sound technology integration? Employing the Shulman's teacher knowledge base as a theoretical lens, this study examined the complexity of pre-service teachers' technological pedagogical content knowledge (TPCK) in the context of integrating problem based learning (PBL) and information and communications technology (ICT). Ninety-seven pre-service teachers in this study engaged in a collaborative lesson design project where they applied pedagogical knowledge about PBL to design a technology integrated lesson in their subject area of teaching. Data were collected from two sources: survey and lesson design artifacts. Data analyses revealed that while participants had theoretical understandings of pedagogical knowledge about PBL, their lesson designs showed a mismatch among technology tools, content representations, and pedagogical strategies, indicating conflicts in translating pedagogical content knowledge into designing pedagogically sound, technology integrated lessons. The areas that students perceived to be particularly challenging and difficult include: a) generating authentic and ill-structured problems for a chosen content topic, b) finding and integrating ICT tools and resources relevant for the target students and learning activities, and c) designing tasks with a balance between teacher guidance and student independence. The present study suggests the potential of two explanations for such difficulties: lack of intimate connection among beliefs, knowledge, and actions, and insufficient repertoires for teaching with technology for problem based learning.

Near-infrared (NIR) fluorescent probes are increasingly popular in biological imaging and sensing, as long-wavelength (650-900 nm) excitation and emission have the advantages of minimum photodamage, deep tissue penetration, and minimum interference from autofluorescence in living systems. Here, a series of long-wavelength BODIPY dyes SPC, DC-SPC, DPC, and DC-DPC are synthesized conveniently and efficiently. They exhibit excellent photophysical properties in far red to near-infrared region, including large extinction coefficients, high fluorescence quantum yields, good photostability, and reasonable two-photon absorption cross section. Comparison of single-molecular imaging confirms that DPC is a much more efficient and more photostable NIR fluorophore than the commonly used Cy5. Also importantly, two kinds of convenient functionalization sites have been reserved: the aryl iodide for organometallic couplings and the terminal alkyne groups for click reactions. Further derivatives DC-SPC-PPh3 exhibit specificity to localize in mitochondria. The introduction of triphenylphosphonium (TPP) moieties mediates its hydrophilic-lipophilic balance and makes DC-SPC-PPh3 appropriate for cell labeling. Their long-wavelength emission at ∼650 nm can efficiently avoid the spectral crosstalk with other probes emitting in the visible light region. Superior photostability, low cytotoxicity, and two-photon excitable properties demonstrate its utility as a standard colocalizing agent to estimate the other probes' local distribution.

Meaningful learning requires deep engagement with ideas. Deep engagement is supported by the critical thinking skill of argumentation. Learning to argue represents an important way of thinking that facilitates conceptual change and is essential for problem solving. In order to appropriately apply argumentation practices to learning, we first discuss reasons for using argumentation in learning environments or instruction. Next, we describe the skills of argumentation along with difficulties that learners experience when trying to argue. Following a brief description of the kinds of argumentation to persuade an audience of the validity of your position or solution (rhetorical) or to attempt to resolve differences in opinions or solutions (dialectical), we describe methods and guidelines for eliciting arguments from students. We conclude with processes for assessing the quality of student-generated arguments.

Paper‐based electronics has attracted growing interest owing to many advantages of papers including low‐cost, abundance, flexibility, biocompatibility, and environmental friendliness. Despite recent progress in paper electronics, however, development of a high‐performance paper‐based triboelectric nanogenerator (TENG), which is a power‐generating device that converts mechanical energy into electric energy by coupling triboelectrification and electrostatic induction, remains a challenge mainly due to weak electron‐donating tendency of cellulose‐based papers. In this work, highly conductive ferroelectric cellulose composite papers containing silver nanowires and BaTiO3 nanoparticles are fabricated, and their successful application for realizing a large‐area TENG with enhanced electrical output performance is demonstrated. It is found that triboelectric charge generation on the ferroelectric cellulose composite paper can be promoted by simple poling treatment, which significantly enhances TENG performance. The ferroelectric cellulose composite paper–based TENG exhibits an electrical output performance that surpasses those of aluminum‐based and pristine cellulose–based TENGs by more than two times, as well as outstanding output stability without a noticeable degradation in performance during 10 000 cycles of a repeated pushing test. The work demonstrates the great potential of multifunctional cellulose‐based papers for TENG and other self‐powered electronic applications.

A range of varying chromophore nitroxide free radicals and their nonradical methoxyamine analogues were synthesized and their linear photophysical properties examined. The presence of the proximate free radical masks the chromophore’s usual fluorescence emission, and these species are described as profluorescent. Two nitroxides incorporating anthracene and fluorescein chromophores (compounds 7 and 19, respectively) exhibited two-photon absorption (2PA) cross sections of approximately 400 G.M. when excited at wavelengths greater than 800 nm. Both of these profluorescent nitroxides demonstrated low cytotoxicity toward Chinese hamster ovary (CHO) cells. Imaging colocalization experiments with the commercially available CellROX Deep Red oxidative stress monitor demonstrated good cellular uptake of the nitroxide probes. Sensitivity of the nitroxide probes to H2O2-induced damage was also demonstrated by both one- and two-photon fluorescence microscopy. These profluorescent nitroxide probes are potentially powerful tools for imaging oxidative stress in biological systems, and they essentially “light up” in the presence of certain species generated from oxidative stress. The high ratio of the fluorescence quantum yield between the profluorescent nitroxide species and their nonradical adducts provides the sensitivity required for measuring a range of cellular redox environments. Furthermore, their reasonable 2PA cross sections provide for the option of using two-photon fluorescence microscopy, which circumvents commonly encountered disadvantages associated with one-photon imaging such as photobleaching and poor tissue penetration.