Blended learning combines online digital resources with traditional classroom activities and enables students to attain higher learning performance through well-defined interactive strategies ...involving online and traditional learning activities. Learning analytics is a conceptual framework and as a part of our Precision education used to analyze and predict students' performance and provide timely interventions based on student learning profiles. This study applied learning analytics and educational big data approaches for the early prediction of students' final academic performance in a blended Calculus course. Real data with 21 variables were collected from the proposed course, consisting of video-viewing behaviors, out-of-class practice behaviors, homework and quiz scores, and after-school tutoring. This study applied principal component regression to predict students' final academic performance. The experimental results show that students' final academic performance could be predicted when only one-third of the semester had elapsed. In addition, we identified seven critical factors that affect students' academic performance, consisting of four online factors and three traditional factors. The results showed that the blended data set combining online and traditional critical factors had the highest predictive performance.
In sharp contrast to many other cancer types, the incidence and mortality of endometrial cancer continue to grow. This unfortunate trend is, in no small part, a result of the worldwide obesity ...epidemic. More than half of endometrial cancers are currently attributable to obesity, which is recognized as an independent risk factor for this disease. In this review, we identify the molecular mechanisms by which obesity and adipose tissue contribute to the pathogenesis of endometrial cancer. We further discuss the impact of obesity on the clinical management of the disease and examine the development of rational behavioral and pharmaceutical interventions aimed at reducing endometrial cancer risk, improving cancer outcomes, and preserving fertility in an increasingly younger population of patients with endometrial cancer.
Nanocasting is a powerful method for creating materials that are more difficult to synthesize by conventional processes. We summarize recent developments in the synthesis of various structured porous ...solids, covering silica, carbon, and other nonsiliceous solids that are created by a nanocasting pathway. Structure replication on the nanometer length scale allows materials' properties to be manipulated in a controlled manner, such as tunable composition, controllable structure and morphology, and specific functionality. The nanocasting pathway with hard templates opens the door to the design of highly porous solids with multifunctional properties and interesting application perspectives.
The nanocasting pathway from hard templates, a versatile synthetic strategy, has successfully been applied for the creation of porous solids (see figure). The obtained structures can be precisely tailored by selecting a suitable template, precursor, and synthetic conditions, and the resulting materials lend themselves to further, spatially controlled modification.
Purpose:
TOPAS (TOol for PArticle Simulation) is a particle simulation code recently developed with the specific aim of making Monte Carlo simulations user-friendly for research and clinical ...physicists in the particle therapy community. The authors present a thorough and extensive experimental validation of Monte Carlo simulations performed with TOPAS in a variety of setups relevant for proton therapy applications. The set of validation measurements performed in this work represents an overall end-to-end testing strategy recommended for all clinical centers planning to rely on TOPAS for quality assurance or patient dose calculation and, more generally, for all the institutions using passive-scattering proton therapy systems.
Methods:
The authors systematically compared TOPAS simulations with measurements that are performed routinely within the quality assurance (QA) program in our institution as well as experiments specifically designed for this validation study. First, the authors compared TOPAS simulations with measurements of depth-dose curves for spread-out Bragg peak (SOBP) fields. Second, absolute dosimetry simulations were benchmarked against measured machine output factors (OFs). Third, the authors simulated and measured 2D dose profiles and analyzed the differences in terms of field flatness and symmetry and usable field size. Fourth, the authors designed a simple experiment using a half-beam shifter to assess the effects of multiple Coulomb scattering, beam divergence, and inverse square attenuation on lateral and longitudinal dose profiles measured and simulated in a water phantom. Fifth, TOPAS’ capabilities to simulate time dependent beam delivery was benchmarked against dose rate functions (i.e., dose per unit time vs time) measured at different depths inside an SOBP field. Sixth, simulations of the charge deposited by protons fully stopping in two different types of multilayer Faraday cups (MLFCs) were compared with measurements to benchmark the nuclear interaction models used in the simulations.
Results:
SOBPs’ range and modulation width were reproduced, on average, with an accuracy of +1, −2 and ±3 mm, respectively. OF simulations reproduced measured data within ±3%. Simulated 2D dose-profiles show field flatness and average field radius within ±3% of measured profiles. The field symmetry resulted, on average in ±3% agreement with commissioned profiles. TOPAS accuracy in reproducing measured dose profiles downstream the half beam shifter is better than 2%. Dose rate function simulation reproduced the measurements within ∼2% showing that the four-dimensional modeling of the passively modulation system was implement correctly and millimeter accuracy can be achieved in reproducing measured data. For MLFCs simulations, 2% agreement was found between TOPAS and both sets of experimental measurements. The overall results show that TOPAS simulations are within the clinical accepted tolerances for all QA measurements performed at our institution.
Conclusions:
Our Monte Carlo simulations reproduced accurately the experimental data acquired through all the measurements performed in this study. Thus, TOPAS can reliably be applied to quality assurance for proton therapy and also as an input for commissioning of commercial treatment planning systems. This work also provides the basis for routine clinical dose calculations in patients for all passive scattering proton therapy centers using TOPAS.
Enzymatic reactions and related protein conformational dynamics are complex and inhomogeneous, playing crucial roles in biological functions. The relationship between protein conformational dynamics ...and enzymatic reactions has been a fundamental focus in modern enzymology. It is extremely difficult to characterize and analyze such complex dynamics in an ensemble-averaged measurement, especially when the enzymes are associated with multiple-step, multiple-conformation complex chemical interactions and transformations. Beyond the conventional ensemble-averaged studies, real-time single-molecule approaches have been demonstrated to be powerful in dissecting the complex enzymatic reaction dynamics and related conformational dynamics. Single-molecule enzymology has come a long way since the early demonstrations of the single-molecule spectroscopy studies of enzymatic dynamics about two decades ago. The rapid development of this fundamental protein dynamics field is hand-in-hand with the new development of single-molecule imaging and spectroscopic technology and methodology, theoretical model analyses, and correlations with biological preparation and characterization of the enzyme protein systems. The complex enzymatic reactions can now be studied one molecule at a time under physiological conditions. Most exciting developments include active manipulation of enzymatic conformational changes and energy landscape to regulate and manipulate the enzymatic reactivity and associated conformational dynamics, and the new advancements have established a new stage for studying complex protein dynamics beyond by simply observing but by actively manipulating and observing the enzymatic dynamics at the single-molecule sensitivity temporally and spatially.
Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi2Te3 ...with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi2Te3 is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi2Te3 also points to promising potential for high-temperature spintronics applications.
Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize ...stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue-to-bone interface, and concludes with a summary of challenges and future directions.
Summary
Background
Chronic exposure to ultraviolet (UV) radiation (mainly UVA) induces a sustained increase of matrix metalloproteinases (MMPs), especially MMP1, MMP2, MMP3 and MMP9 in human skin ...fibroblasts. MMPs can lead to the degradation of fibrous connective tissue, which is the main cause of skin photoageing. The molecular mechanisms through which fibroblasts sense UVA and trigger the cell signalling pathways involved in the upregulation of MMPs have not been well elucidated.
Objectives
Here, we investigated the function and potential mechanisms of photoageing of opsin (OPN)3 in normal human dermal fibroblasts (NHDFs).
Methods
Real‐time polymerase chain reaction and Western blot analysis were used to analyse the expression levels of OPN3 in NHDFs and photoageing models. Subsequently, NHDFs transfected with OPN3 inhibitors and indicators related to photoageing before and after UVA irradiation included expression levels of MMP1, MMP2, MMP3 and MMP9, and signalling pathway protein molecules were examined.
Results
We provide evidence that OPN3 initiates UVA phototransduction in NHDFs. OPN3 triggers phosphorylation of activator protein 1 and ultimately upregulates MMP1, MMP2, MMP3 and MMP9 in NHDFs through activating Ca2+/calmodulin‐dependent protein kinase II, cyclic adenosine monophosphate response element‐binding protein, extracellular signal‐regulated kinase, c‐JUN N‐terminal kinase and p38. Here, we demonstrate for the first time that OPN3 is the key sensor responsible for upregulating MMP1, MMP2, MMP3 and MMP9 in NHDFs following UVA exposure via the calcium‐dependent G protein‐coupled signalling pathway.
Conclusions
Our studies provide insights into the understanding of the molecular mechanisms through which human skin cells respond to UVA radiation and may reveal molecular targets for skin photoageing prevention or clinical management.
What's already known about this topic?
Photoaged fibroblasts accumulate with long‐term ultraviolet (UV) exposure.
Matrix metalloproteinases (MMPs) play an important role in the pathogenesis of photoageing.
MMP1, MMP2, MMP3 and MMP9 are responsible for the destruction of fibroblast collagen in severely photodamaged skin.
Opsins (OPNs) are light‐sensitive members of the superfamily of heptahelical G protein‐coupled receptors, a family of cell surface receptors that are activated by a variety of stimuli and mediate signalling across membranes.
What does this study add?
OPN3 is highly expressed in fibroblasts and responds to UVA irradiation.
OPN3 regulates the expression of MMP1, MMP2, MMP3 and MMP9 via the calcium‐dependent G protein‐coupled signalling pathway.
OPN3 is a light‐sensitive sensor that plays an important role in photoageing of the skin.
Linked Comment: Julie Thornton. Br J Dermatol 2020; 182:1086–1087.
Plain language summary available online
Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this Letter we study static ...black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics.
To elucidate the mechanisms behind the enhanced T_{c} in monolayer (1 ML) FeSe on SrTiO_{3} (STO), we grew highly strained 1 ML FeSe on the rectangular (100) face of rutile TiO_{2}, and observed the ...coexistence of replica bands and superconductivity with a T_{c} of 63 K. From the similar T_{c} between this system and 1ML FeSe on STO (001), we conclude that strain and dielectric constant are likely unimportant to the enhanced T_{c} in these systems. A systematic comparison of 1 ML FeSe on TiO_{2} with other systems in the FeSe family shows that while charge transfer alone can enhance T_{c}, it is only with the addition of interfacial electron-phonon coupling that T_{c} can be increased to the level seen in 1 ML FeSe on STO.
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