Tissues and cells in organism are continuously exposed to complex mechanical cues from the environment. Mechanical stimulations affect cell proliferation, differentiation, and migration, as well as ...determining tissue homeostasis and repair. By using a specially designed skin-stretching device, we discover that hair stem cells proliferate in response to stretch and hair regeneration occurs only when applying proper strain for an appropriate duration. A counterbalance between WNT and BMP-2 and the subsequent two-step mechanism are identified through molecular and genetic analyses. Macrophages are first recruited by chemokines produced by stretch and polarized to M2 phenotype. Growth factors such as HGF and IGF-1, released by M2 macrophages, then activate stem cells and facilitate hair regeneration. A hierarchical control system is revealed, from mechanical and chemical signals to cell behaviors and tissue responses, elucidating avenues of regenerative medicine and disease control by demonstrating the potential to manipulate cellular processes through simple mechanical stimulation.
Augmented reality (AR) is capable of providing students with proper situated scaffolding via overlaying rich media objects on the real‐world learning context. This paper examines the potential of AR ...to address existing problems with insufficient scaffolding in video learning materials for English as a foreign language (EFL) learners. Thus, an AR video‐enhanced learning (ARVEL) method was designed to assist students’ EFL learning. Furthermore, an experiment was carried out to investigate the influences of the implemented method on students' EFL learning outcomes. The experimental results displayed that the ARVEL method significantly improved the students' learning achievements and intrinsic motivation, and enhanced their satisfaction with EFL learning, compared to the students learning EFL with conventional video‐based learning.
Practitioner Notes
What is already known about this topic
Learning experience of English as a foreign language (EFL) is highly related to the experience in actual learning contexts.
The significance of providing students with proper assistance in a situated learning environment has been emphasized.
Just observing videos might be inadequate for advancing students' reflection on learning tasks in video‐based learning.
What this paper adds
An augmented reality (AR) video‐enhanced learning method was proposed to assist students' EFL learning.
An AR video‐enhanced learning (ARVEL) system was designed based on the implemented method.
It was evidenced that the implemented method effectively improved students' learning achievements and motivation.
The students display a higher degree of satisfaction with EFL learning than with the video‐enhanced learning method.
Implications for practice and/or policy
The ARVEL method could be a good reference for implementing an EFL learning environment.
More kinds of assistance could be designed as scaffolding for assisting students' EFL learning.
It is worth probing the influences of the ARVEL on students' learning of more vocabulary and concepts.
Abstract Background In this study, we tested the hypothesis that a combined adipose-derived mesenchymal stem cell (ADMSC) and ADMSC-derived exosome therapy protected rat kidney from acute ...ischemia–reperfusion (IR) injury (i.e., ligation both renal arteries for 1 h and reperfusion for 72 h prior to euthanization). Methods and Results Adult-male SD rats (n = 40) were equally categorized into group 1 (sham control), group 2(IR), group 3IR + exosome (100 μg), group 4 IR + ADMSC (1.2 × 106 cells), and group 5 (IR-exosome-ADMSC). All therapies were performed at 3 h after IR procedure from venous administration. By 72 h, the creatinine level and kidney injury score were lowest in group 1 and highest in group 2, significantly higher in group 3 than in groups 4 and 5, and significantly higher in group 4 than in group 5 (all P < 0.0001). The protein expression of inflammatory (TNF-α/NF-κB/IL-1β/MIF/PAI-1/Cox-2), oxidative-stress (NOX-1/NOX-2/oxidized protein), apoptotic (Bax/caspase-3/PARP), and fibrotic (Smad3/TGF-β) biomarkers showed an identical pattern, whereas the anti-apoptotic (Smad1/5, BMP-2) and angiogenesis (CD31/vWF/angiopoietin) biomarkers and mitochondrial cytochrome-C showed an opposite pattern of creatinine level among the five groups (all P < 0.001). The microscopic findings of glomerular-damage (WT-1), renal tubular-damage (KIM-1), DNA-damage (γ-H2AX), inflammation (MPO/MIF/CD68) exhibited an identical pattern, whereas the podocyte components (podocin/p-cadherin/synaptopodin) displayed a reversed pattern of creatinine level (all P < 0.0001). Conclusion Combined exosome-ADMSC therapy was superior to either one for protecting kidney from acute IR injury.
Although a great deal of research has evidenced the effects of proper instructional design on multimedia learning, most has focused on the cognitive aspects of learning, with little concern about the ...role of affective-motivational states in multimedia learning. In this study, an AR game-based learning method was designed via integrating AR technology and a digital game for assisting students’ learning, and for probing the factors of metacognitive and motivational factors of multimedia learning. A context-aware mobile learning system with reflection prompts was developed based on the implemented approach. Furthermore, a 2 × 2 experiment was conducted to identify the impacts of the implemented approach on elementary school science learning. Four groups learned with different media mechanisms (i.e., AR or Non-AR) and gaming mechanisms (i.e., Game or Non-game) during an elementary school field trip. The research results displayed that interaction between the AR and game approaches did not exist, and both significantly promoted the students’ learning motivation; however, only the game approach significantly improved the students’ learning achievements and flow states. This study evidenced the significance of flow state in a reflective context in multimedia learning. Such a result also stresses that digital games play an important role in promoting affective-motivational states in multimedia learning.
In this paper, an inquiry‐based ubiquitous gaming approach was proposed. The objective of the study was to enhance students’ performances in in‐field learning activities. To show the advantages of ...the approach, an experiment was carried out to assess the effects of it on students’ learning achievement, motivation, critical thinking, and problem solving. Furthermore, the students’ behavioral patterns were investigated via content and sequential analysis methods. The experimental outcomes show that the approach promoted students’ performances of learning achievement and intrinsic motivation; moreover, the students’ perceptions of their problem solving and critical thinking were significantly promoted as well. The learning behavior analysis further show that the designated approach stimulated the participants to actively engage in field observation, comparison, and data searching in the context ware in‐field learning activity.
Reading has been regarded as a medium for learning science, revealing the importance of enhancing learners’ reading competence in science education. The critical features of science texts are their ...multiple representations, such as text and visual elements, which assist the representation of science concepts. A multimedia learning environment can present relevant materials in various formats and help students to process the materials in meaningful ways, for example, by integrating learning materials with relevant prior concepts, and organizing them into a consistent and coherent cognitive structure. However, some issues with multimedia instructional design have been proposed, such as students’ cognitive load and learning motivations. In this study, an augmented reality‐based science learning system was developed based on the contiguity principle of multimedia learning in order to promote students’ science learning. Moreover, an experiment was conducted on a natural science course in an elementary school to assess the effectiveness of the implemented system on students’ learning. The experimental results display that the students learning with this approach found made significant gains in their learning achievements and motivations compared to those learning science with conventional multimedia science learning; moreover, their perceptions of extraneous cognitive load were significantly reduced during the learning activity.
Some oral probiotics have been shown to prevent necrotizing enterocolitis (NEC) and decrease mortality effectively in preterm very low birth weight (PVLBW) infants. However, it is unclear whether a ...single probiotic or a mixture of probiotics is most effective for the prevention of NEC.
A meta-analysis was conducted by reviewing the most up to date literature to investigate whether multiple strains probiotics are more effective than a single strain in reducing NEC and death in PVLBW infants.
Relevant studies were identified by searches of the MEDLINE, EMBASE, and Cochrane CENTRAL databases, from 2001 to 2016.
The inclusion criteria were randomized controlled trials of any enteral probiotic supplementation that was initiated within the first 7 days and continued for at least 14 days in preterm infants (≤ 34 weeks' gestation) and/or those of a birth weight ≤1500 g.
A total of 25 trials (n = 7345 infants) were eligible for inclusion in the meta-analysis using a fixed-effects model. Multiple strains probiotics were associated with a marked reduction in the incidence of NEC, with a pooled OR of 0.36 (95% CI, 0.24-0.53; P < .00001). Single strain probiotic using Lactobacillus species had a borderline effect in reducing NEC (OR of 0.60; 95% CI 0.36-1.0; P = .05), but not mortality. Multiple strains probiotics had a greater effectiveness in reducing mortality and were associated with a pooled OR of 0.58 (95% CI, 0.43-0.79; P = .0006). Trials using single strain of Bifidobacterium species and Saccharomyces boulardii did not reveal any beneficial effects in terms of reducing NEC or mortality.
This updated report found that multiple strains probiotics appear to be the most feasible and effective strategy for the prevention of NEC and reduction of mortality in PVLBW neonates. Further clinical trials should focus on which probiotic combinations are most effective.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cracks, the major vehicle for material failure, undergo a micro-branching instability at ∼40% of their sonic limiting velocity in three dimensions. Recent experiments showed that in thin systems ...cracks accelerate to nearly their limiting velocity without micro-branching, until undergoing an oscillatory instability. Despite their fundamental importance, these dynamic instabilities are not explained by the classical theory of cracks, which is based on linear elasticity and an extraneous local symmetry criterion to predict crack paths. We develop a two-dimensional theory for predicting arbitrary paths of ultrahigh-speed cracks, which incorporates elastic nonlinearity without extraneous criteria. We show that cracks undergo an oscillatory instability controlled by small-scale, near crack-tip, elastic nonlinearity. This instability occurs above an ultrahigh critical velocity and features an intrinsic wavelength proportional to the ratio of the fracture energy to the elastic modulus, in quantitative agreement with experiments. This ratio emerges as a fundamental scaling length assumed to play no role in the classical theory of cracks, but shown here to strongly influence crack dynamics.
Quantum memory is an important component in the long-distance quantum communication based on the quantum repeater protocol. To outperform the direct transmission of photons with quantum repeaters, it ...is crucial to develop quantum memories with high fidelity, high efficiency and a long storage time. Here, we achieve a storage efficiency of 92.0 (1.5)% for a coherent optical memory based on the electromagnetically induced transparency scheme in optically dense cold atomic media. We also obtain a useful time-bandwidth product of 1200, considering only storage where the retrieval efficiency remains above 50%. Both are the best record to date in all kinds of schemes for the realization of optical memory. Our work significantly advances the pursuit of a high-performance optical memory and should have important applications in quantum information science.
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs (typically consisting of 18–25 nucleotides) that negatively control expression of target genes at the post-transcriptional level. Owing to the ...biological significance of miRNAs, miRTarBase was developed to provide comprehensive information on experimentally validated miRNA–target interactions (MTIs). To date, the database has accumulated >13,404 validated MTIs from 11,021 articles from manual curations. In this update, a text-mining system was incorporated to enhance the recognition of MTI-related articles by adopting a scoring system. In addition, a variety of biological databases were integrated to provide information on the regulatory network of miRNAs and its expression in blood. Not only targets of miRNAs but also regulators of miRNAs are provided to users for investigating the up- and downstream regulations of miRNAs. Moreover, the number of MTIs with high-throughput experimental evidence increased remarkably (validated by CLIP-seq technology). In conclusion, these improvements promote the miRTarBase as one of the most comprehensively annotated and experimentally validated miRNA–target interaction databases. The updated version of miRTarBase is now available at http://miRTarBase.cuhk.edu.cn/.
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