The spread of COVID-19 has presented enormous challenges to higher education students all over the world, prompting these students to switch from face-to-face to online courses. Previous researchers ...have focused on how university students in specific countries engage in online learning. However, the engagement of university students in online learning on a larger scale has not been thoroughly investigated. This study provides a comprehensive discussion of student engagement in online learning at large higher education institutions around the world during the COVID-19 pandemic. This study focuses university students need to attend university online. Since “engagement” is considered a multidimensional term, this review evaluates studies related to the idea of global university students’ online “engagement” in terms of three unique but interconnected dimensions: behavioral, conscious, and emotional engagement. This review can serve as a reference point for higher education institutions, education policymakers, and teachers in various countries as they work to develop more effective solutions to increase online participation of university students.
Several overloaded-induced overturning incidents of girder bridges with single-column piers have occurred in recent years, resulting in significant casualties and economic losses. Temperature, in ...addition to overloading, may also play a role in exacerbating bridge overturning. To investigate the association between temperature and bridge overturning, an explicit finite element model (EFEM) of a three-span concrete curved continuous bridge considering nonlinearities was developed to simulate overall collapse. The effects of uniform and gradient temperatures on the overall overturning stability of curved and straight bridges were evaluated based on the EFEMs. Furthermore, the temperature–bridge coupling model and temperature–vehicle–bridge coupling model were utilized to examine how gradient temperature influences bridge overturning. The results show that the overall overturning collapse of a bridge follows four stages: stabilization, transition, risk and overturning. Variations in uniform temperature from −30 °C to 60 °C had a negligible effect on the ultimate vehicle weight for bridge overturning, with a variation of less than 1%. As the gradient temperature ranged from −30 °C to 60 °C, curved bridges show less than a 2% variation in ultimate vehicle weights, compared to a range of −6.1% to 11.7% for straight bridges. The torsion caused by positive gradient temperature in curved bridges can exacerbate bridge overturning, while negative gradient temperature in straight bridges can lead the girder to ‘upward warping’, facilitating girder separation from bearings. Monitoring the girder rotation angle and vertical reaction force of bearings can serve as important indicators for comparing the stability of bridges.
There are differences between the dynamic deflection and bending moment (strain) in the same section of continuous girder bridges. However, the selection of the response for calculating dynamic ...amplification factors (DAFs), which are essential for bridge health monitoring and safety assessment, remains controversial. Modes may play a role in the relationship between the deflection DAF and the bending moment DAF in both numerical analysis and field tests. To investigate the distinctions between the DAFs of the deflection and bending moment in a continuous girder bridge, functional expressions of the DAFs were derived, taking into account multi-factor coupling under concentrated forces. The interaction effects of the mode and road surface condition (RSC), vehicle speed, bridge span length, and span number on the deflection DAF, the bending moment DAF, and the ratio of the deflection DAF to the bending moment DAF (RDM) of precast continuous box-girder bridges were analyzed using vehicle-bridge interaction. To ensure the accuracy of the DAF in numerical computations and experimental tests, two types of accuracy indexes and the corresponding cut-off modes were provided. Validation was conducted by performing dynamic load tests on two field bridges. The results indicate that different modes have a significant effect on the RDM of the mid-span section of a bridge. When considering multiple factors, the deflection DAF and bending moment DAF of the mid-span section increased rapidly with the considered modes and then stabilized. Statistically, the RDM of all nine bridges ranged from 1.00 to 1.12, indicating that the deflection DAF was greater than the bending moment DAF. The suggested cut-off modes can be utilized for efficient and accurate calculation of the DAF and response signal fidelity.
IntroductionMicrocurrent therapy (MCT) is a rising conservative treatment for patients with knee osteoarthritis (OA). Considering its potential benefits and convenience, MCT’s application in those ...individuals with knee OA is capacious. However, no plausible clinical evidence has proved its unequivocal advantages in treating knee OA conservatively. The purpose of this study is to determine whether MCT is helpful in pain management and promoting function of knee OA and is safe in the treatment of knee OA in adult patients.Methods and analysisWe will search through MEDLINE, Embase, Cochrane Library, Web of Science and Google Scholar from inception to 15 March 2023. Original studies will include randomised controlled trials of patients treated with MCT. Two authors will independently screen, select studies, extract data and perform risk of bias assessment. Data consistently reported across studies will be pooled using random-effects meta-analysis. Heterogeneity will be evaluated using Cochrane’s Q statistic and quantified using I2 statistics. Graphical and formal statistical tests will be used to assess for publication bias.Ethics and disseminationEthical approval will not be needed for this study as the data will be extracted from already published studies. The results of this review will be published in a peer-reviewed journal and presented at conferences.PROSPERO registration numberCRD42022319828
We investigate the formation of close-in planets in near-coplanar eccentric hierarchical triple systems via the secular interaction between an inner planet and an outer perturber (Coplanar ...High-eccentricity Migration; CHEM). We generalize the previous work on the analytical condition for successful CHEM for point masses interacting only through gravity by taking into account the finite mass effect of the inner planet. We find that efficient CHEM requires that the systems should have m1 < m0 and m1 < m2. In addition to the gravity for point masses, we examine the importance of the short-range forces, and provide an analytical estimate of the migration timescale. We perform a series of numerical simulations in CHEM for systems consisting of a Sun-like central star, giant gas inner planet, and planetary outer perturber, including the short-range forces and stellar and planetary dissipative tides. We find that most of such systems end up with a tidal disruption; a small fraction of the systems produce prograde hot Jupiters (HJs), but no retrograde HJ. In addition, we extend CHEM to super-Earth mass range, and show that the formation of close-in super-Earths in prograde orbits is also possible. Finally, we carry out CHEM simulation for the observed hierarchical triple and counter-orbiting HJ systems. We find that CHEM can explain a part of the former systems, but it is generally very difficult to reproduce counter-orbiting HJ systems.
A skip-connection learning framework-based convolution neural network (CNN) has recently achieved great success in image super-resolution (SR). However, most CNN models based on the skip-connection ...learning framework do not fully make use of potential multi-scale features of images. In this paper, we propose a multi-scale skip-connection network (MSN) to improve the visual quality of the image SR. First, convolution kernels with different sizes are exploited to capture the multi-scale features of LR images. All the feature-maps captured by convolution kernels of the same size are direct input into a multi-scale hybrid group (MHG); second, the convolution layers of each MHG are composed of dilated convolutions and standard convolutions. The hybrid convolutions can fully train feature details obtained from preceding and current scale convolution layers; three, the output of each hybrid convolution layer is fed into subsequent hybrid convolution layers by skip-connections, thus producing dense connections; lastly, the meta-upscale module is used as the upscale module, which can magnify the trained feature maps arbitrary scale factors. By being evaluated on a wide variety of images, the proposed MSN network achieves an advantage over the state-of-the-art methods in terms of both numerical results and visual quality.
To investigate the effects of Mingmu Xiaoyao granules (MMXY) on the morphology and function of the retina and the mechanism of PI3K/Akt/mTOR pathway-related proteins in rats with anxiety and ...depression induced by chronic unpredictable mild stress (CUMS).
Fifty-two male Sprague Dawley rats were randomly allocated to either a control (n = 14) or a simulated CUMS group (n = 38). The CUMS model was established successfully at 4 weeks. Six rats in each group were randomly selected to be sacrificed and their retinas isolated for histological examination. At 5 weeks, rats in the CUMS group were randomly allocated to the following groups: Model (CUMS + pure water), MMXY-H (CUMS + MMXY 7.2 g/kg/d), MMXY-L (CUMS + MMXY 3.6 g/kg/d), and CBZ (CUMS + Carbamazepine 20 mg/kg/d), with eight rats in each group. All rats were given the relevant intervention once a day. At 12 weeks, sucrose preference and open field tests were performed to evaluate the anxiety and depression status of rats. In live rats, optical coherence tomography angiography was used to measure retinal thickness and blood flow, while electroretinograms (ERGs) and visual evoked potentials (VEPs) were used to evaluate retinal function. The next day, the specimens were sacrificed for serological, histological, immunofluorescence, Western blot and transmission electron microscopy examinations to explore the mechanism of MMXY in CUMS rats.
MMXY improved the anxiety and depression-like behavior of rats. Results of optical coherence tomography angiography showed that MMXY improved retinal inner thickness and blood flow in CUMS rats. MMXY improved the amplitude of a- and b-waves in the scotopic and photopic ERG, as well as N2 and P2 peak time and amplitude in the flash-VEP in CUMS rats. Retinal histological staining and transmission electron microscopy showed that MMXY reversed retinal morphology and ultrastructure in CUMS rats. MMXY reduced the expression of Beclin1 and LC3I/II proteins, regulated the PI3K/Akt/mTOR pathway, inhibited autophagy, and had a protective effect on the retina in CUMS rats.
MMXY may effectively improve retinal morphology and function as well as anxiety and depression-like behaviors in CUMS rats by regulating the PI3K/Akt/mTOR signaling pathway.
Context
The adsorptions of toxic gases SO
2
and H
2
S on 2D α/β/γ-FeB
6
monolayer were investigated using density functional theory calculations. To analyze the interaction between gas molecule H
2
...S/SO
2
and α/β/γ-FeB
6
monolayer, we calculated adsorption energy, adsorption distance, Mullikan charge, charge density difference, band structure, the density of states, work function, and theoretical recovery time. The adsorption energies show that H
2
S/SO
2
is chemisorbed on α/β-FeB
6
while H
2
S/SO
2
is physiosorbed on γ-FeB
6
monolayer. As a result, γ-FeB
6
has a short recovery time for H
2
S (5.71×10
−8
s)/SO
2
(1.94×10
−5
s) due to modest adsorption. Therefore, γ-FeB6 may be a promising candidate for reusable H2S/SO2 sensors at room temperature. Although H2S is chemisorbed on α/β-FeB6, as the working temperature rises to 500 K, the recovery time of α/β-FeB6 for H2S can decrease to 1.13×10−1 s and 2.08×10−1 s, respectively, which are well within the detectable range. So, α/β-FeB6 monolayer also may be a good candidate for H2S gas sensor.
Methods
Calculations were performed at GGA-PBE/DNP level using the Dmol
3
module implemented in the Material Studio 2018 software package.
Duboisia is an Australian native woody species of the Solanaceae family, a crucial source of alkaloids, and is naturally extracted for pharmaceuticals. The alkaloid content of the four naturally ...occurring species of Duboisia, i.e., Duboisia myoporoides R. Br., Duboisia leichhardtii F. Muell., Duboisia hopwoodii F. Muell. and Duboisia arenitensis, is not conducive for large-scale commercial extraction. High-value hybrids between D. myoporoides R. Br. and D. leichhardtii F. Muell. have become the commercial crop for the industry. Propagation of these hybrids is key for progression of this industry, especially for the establishment and expansion of plantations and to replenish old plantations. Commercial propagation of Duboisia completely depends on cutting propagation to ensure true-to-type propagules. Cutting propagation of this species is associated with several challenges and has been a hurdle for industry expansion for many years. Micropropagation can be an efficient and sustainable alternative for Duboisia clonal propagation and is a faster and cleaner propagation avenue for elite propagules. This review compiles the research attempts made in the space of Duboisia micropropagation and provides an update on recent advancements to understand the technical capacity, progress and challenges towards a commercial micropropagation platform.
Purpose
It has been shown that activation of autophagy promotes the development of pulmonary arterial hypertension (PAH). Meanwhile, forkhead box M1 (FOXM1) has been found to induce autophagy in ...several types of cancer. However, it is still unclear whether FOXM1 mediates autophagy activation in PAH, and detailed mechanisms responsible for these processes are indefinite.
Method
PAH was induced by a single intraperitoneal injection of monocrotaline (MCT) to rats. The right ventricle systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), percentage of medial wall thickness (%MT), α-smooth muscle actin (α-SMA) staining, and Ki67 staining were performed to evaluate the development of PAH. The protein levels of FOXM1, phospho-focal adhesion kinase (p-FAK), FAK, and LC3B were determined by immunoblotting or immunohistochemistry.
Results
FOXM1 protein level and FAK activity were significantly increased in MCT-induced PAH rats, this was accompanied with the activation of autophagy. Pharmacological inhibition of FOXM1 or FAK suppressed MCT-induced autophagy activation, decreased RVSP, RVHI and %MT in MCT-induced PAH rats, and inhibited the proliferation of pulmonary arterial smooth muscle cells and pulmonary vessel muscularization in MCT-induced PAH rats.
Conclusion
FOXM1 promotes the development of PAH by inducing FAK phosphorylation and subsequent activation of autophagy in MCT-treated rats.
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