Due to the emergence of new technologies, reforms in higher education require changes in traditional education. The flipped classroom approach can be a solution to such educational changes to create ...a student-centered individual learning environment. This approach, which is a type of blended learning, has effectively integrated traditional education and social networks using both environments inside and outside the classroom. The current review is to provide an overview of flipped classroom studies in language teaching contexts. Particularly, the study put emphasis on revealing and addressing the potential benefits and challenges of flipped classroom approach for teaching using social media. It focused on learning environments that students were exposed to the lecture content before the class in a collaborative and interactive learning environment using well-known social media applications. Twenty-five journal publications of flipped classrooms were analyzed in terms of their flipped learning activities, learner achievement, learner attitude, and challenges encountered. The analysis of the selected studies showed that the flipped classroom approach has a positive effect on learning, reducing cognitive load, involvement, accuracy, motivation, attitude, and satisfaction with the course and self-efficacy in higher education, and one of the most important challenges of the flipped classroom is the lack of familiarity and appropriate adaptation of students. With the inversion method, there was an increase in teachers’ workload. According to the analysis of the selected research findings, it is concluded that higher education can effectively use this method.
As an attempt to shed more light on the utility of blogs in educational contexts, the current research set out to explore the effectiveness of blog-based writing instruction on the writing skill and ...writing motivation of Chinese English-as-a-Foreign Language (EFL) students. Forty-nine Chinese EFL students from two intact classes in a language school were selected as the participants through convenience sampling. Then they were assigned to an experimental (26 students) and a control condition (23 students) randomly. The students of the experimental group utilized blogs for posting their writing assignments whereas the control group were taught traditionally with no use of blogs or other technology devices. The IELTS writing tasks and L2 writing motivation scale were used for the data collection as pre-and post-tests. The findings revealed that although both groups improved their writing skill and motivation, the participants of the blog group performed better than those in the control group, confirming that the blog-based teaching substantially enhanced the writing skill and writing motivation of the EFL students. These findings may have notable implications for EFL instructors.
Recent studies have revealed robust metabolic changes during cell differentiation. Mitochondria, the organelles where many vital metabolic reactions occur, may play an important role. Here, we report ...the involvement of SIRT3-regulated mitochondrial stress in osteoblast differentiation and bone formation. In both the osteoblast cell line MC3T3-E1 and primary calvarial osteoblasts, robust mitochondrial biogenesis and supercomplex formation were observed during differentiation, accompanied by increased ATP production and decreased mitochondrial stress. Inhibition of mitochondrial activity or an increase in mitochondrial superoxide production significantly suppressed osteoblast differentiation. During differentiation, SOD2 was specifically induced to eliminate excess mitochondrial superoxide and protein oxidation, whereas SIRT3 expression was increased to enhance SOD2 activity through deacetylation of K68. Both SOD2 and SIRT3 knockdown resulted in suppression of differentiation. Meanwhile, mice deficient in SIRT3 exhibited obvious osteopenia accompanied by osteoblast dysfunction, whereas overexpression of SOD2 or SIRT3 improved the differentiation capability of primary osteoblasts derived from SIRT3-deficient mice. These results suggest that SIRT3/SOD2 is required for regulating mitochondrial stress and plays a vital role in osteoblast differentiation and bone formation.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
As a potential major energy resource, gas hydrates are widely found in sub-oceanic sediments and could play an important role in the future of fuels. Many studies have been applied on gas hydrates ...reservoir to understand its accumulation as well as potential industrial values, while the characteristics of sediments favoring gas hydrates accumulation are still unclear. Here, we investigate a gas hydrates reservoir in Shenhu area, Pearl River Mouth Basin, South China Sea (SCS), studying reservoir sediments features to understand controlling factors of gas hydrates accumulation. We sampled sediments of drilling site W19 in this area, which has thick, high saturation gas hydrate layers, for sediments' physical properties analysis (including the grain size, mineral composition, and specific surface area), as well as biological abundance in the gas hydrate-bearing layer and adjacent layers. The results show fine-grained turbidite sediments characterized by poor sorting, high foraminifera abundance, and low clay mineral content, are beneficial to gas hydrate accumulation, while suspended sediments characterized by fine sorting, high calcareous ultra-microfossil abundance, and high clay mineral content, are not conducive to gas hydrate accumulation. Based on these results, we propose that the gas hydrate accumulation in the SCS is controlled by multiple factors, including the sedimentary processes, sorting, biological abundance, mineral composition, and specific surface area. It could potentially reveal the regularity of gas hydrate accumulation on a global scale.
•The absorption capacity and binging effect of minerals on pore water and methane will affect the reserve of gas hydrate.•The effects of different biological components on gas hydrate accumulation are quite different.•The sedimentary process plays a significant role in controlling favorable gas hydrate reservoirs.•The gas hydrate accumulation in low-flux type and diffusion reservoirs is controlled by multiple factors.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tumor cells, including cancer stem cells (CSCs) resistant to radio- and chemotherapy, must enhance metabolism to meet the extra energy demands to repair and survive such genotoxic conditions. ...However, such stress-induced adaptive metabolic alterations, especially in cancer cells that survive radiotherapy, remain unresolved. In this study, we found that CPT1 (Carnitine palmitoyl transferase I) and CPT2 (Carnitine palmitoyl transferase II), a pair of rate-limiting enzymes for mitochondrial fatty acid transportation, play a critical role in increasing fatty acid oxidation (FAO) required for the cellular fuel demands in radioresistant breast cancer cells (RBCs) and radiation-derived breast cancer stem cells (RD-BCSCs). Enhanced CPT1A/CPT2 expression was detected in the recurrent human breast cancers and associated with a worse prognosis in breast cancer patients. Blocking FAO via a FAO inhibitor or by CRISPR-mediated CPT1A/CPT2 gene deficiency inhibited radiation-induced ERK activation and aggressive growth and radioresistance of RBCs and RD-BCSCs. These results revealed that switching to FAO contributes to radiation-induced mitochondrial energy metabolism, and CPT1A/CPT2 is a potential metabolic target in cancer radiotherapy.
Diagenesis significantly influences sandstone reservoir quality, so that a detailed understanding of diagenesis is essential for the identification and prediction of favorable reservoirs. Several ...studies have been conducted on individual sandstone reservoirs in the Bonan Sag, a typical half-graben, oil-producing sag in eastern China, but few have explicitly considered the potential impact of the asymmetric shape of the sag, which is steep in the north and gentle in the south. This research takes full consideration of the tectonic setting and distribution of source rocks in the sag to compare the style, magnitude and timing of diagenesis in the northern Steep Slope and Sag Zone (SSSZ) and the southern Gentle Slope Zone (GSZ) by means of drill core observations, thin section petrography, high resolution scanning electron microscopy, fluid inclusion microthermometry, as well as cathodoluminescence and carbonate stable isotope analysis. Petrographic observations identify the wide-spread occurrence of authigenic quartz and clay minerals in association with dissolved feldspar, as well as abundant carbonate cements occurring as several distinct generations due to evolving pore fluid composition. The SSSZ has variable carbonate mineralogy while ankerite dominates in the GSZ. The homogenization temperature of fluid inclusions in authigenic quartz in the SSSZ has a wider range (93°C–157.9 °C) and lower starting temperature (93 °C) compared with the GSZ (106.2 °C) and is characterized by more lighter carbonate δ13C and δ18O values (δ18O: −14.8‰~-11.3‰, δ13C: 1.1‰–2.7‰ for the SSSZ; δ18O: −11.9‰~-5.8‰, δ13C: 2.9‰–5.5‰ for the GSZ). The results indicate that (1) Diagenetic conditions in the Bonan Sag evolved from alkaline to acidic to alkaline in general, but with distinct late stage carbonate cementation in SSSZ vs GSZ; (2) the diagenetic processes as well as the nature of pore waters varied across different zones and also temporally. Acidic conditions in the SSSZ started earlier and persisted for longer than in the GSZ. (3) The regional differentiation of the diagenetic processes and pore fluid evolution result from the source rock distribution and burial histories which differ across the Bonan Sag because of the asymmetric shape of the half-graben. We propose a model of fluid evolution over space and time which may provide a new framework for understanding the diagenetic processes and the fluid evolution of oil-producing sags and also contribute to the prediction of favorable reservoirs.
•The Es3 in Bonan Sag went through an alkaline-acid-alkaline diagenetic conditions.•The structure of the sag leads to temporal and spatial differences in diagenesis.•Source rock distribution and burial histories are significant controls in diagenesis.•A temporal and spatial diagenesis evolution model was put forward.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Colorless and transparent polyimide (CPI) films with good atomic oxygen (AO) resistance and high thermal endurance are highly required in low earth orbit (LEO) space exploration. Conventional CPI ...films based on fluoro-containing 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) have been widely used in space applications. However, the AO erosion yields and glass transition temperatures (T
) of the 6FDA-based CPI films have to be modified in order to meet the severe serving environments. In the current work, novel CPI films based on a multi-ring fluoro-containing 9,9-bis(trifluoromethyl)xanthene-2,3,6,7-tetracarboxylicdianhydride (6FCDA) monomer were developed. In order to enhance the AO resistance of the derived CPI film, a phosphorus-containing aromatic diamine, 2,5-bis(4-aminophenoxy)phenyldiphenylphosphine oxide (BADPO) was used to polymerize with the dianhydride to create the organo-soluble resin. Then, two phosphorus-containing CPI films (PPI), including PPI-1 (6FDA-BADPO) and PPI-2 (6FCDA-BADPO) were prepared by thermally curing of the PPI solutions at elevated temperatures. The PPI films maintained good optical transparency with transmittance values over 80% at a wavelength of 450 nm. PPI-2 exhibited a T
value of 311.0 °C by differential scanning calorimetry (DSC) measurement, which was 46.7 °C higher than that of the PPI-1 counterpart (T
= 264.3 °C). In addition, the PPI-2 film showed a coefficient of linear thermal expansion (CTE) value of 41.7 × 10
/K in the range of 50~250 °C, which was apparently lower than that of the PPI-1 sample (CTE = 49.2 × 10
/K). Lastly, both of the two PPI films exhibited good AO resistance with the erosion yields (E
) of 6.99 × 10
cm
/atom for PPI-1 and 7.23 × 10
cm
/atom for PPI-2 at an exposure flux of 5.0 × 10
atoms/cm
. The E
values of the current PPI films were obviously lower than that of the standard polyimide (PI) film based on pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA) (E
= 3.0 × 10
cm
/atom).
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Shale oil is attracting increasing attention in the petroleum industry as an essential target of unconventional oil and gas exploration. Recent exploration efforts have indicated that laminar ...carbonates are closely related to the favorable depositional strata of shale oil. This research focused on inter-bedded layers of laminar carbonates as well as mudstone and shale in the Dongying depression of the Bohai Bay Basin in eastern China, and attempted to reveal the genesis and evolution of the carbonates by means of drill core observations, thin sections, high resolution scanning electron microscopic observations, and fluorometric, cathodoluminescence and geochemical analyses. The results demonstrated that: (1) the carbonates could be categorized into two groups, crystalline carbonates and micritic carbonates; (2) the crystalline carbonates were well crystallized and greenish under fluorescent light; and (3) the micritic carbonates were not well crystallized and had biotic textures. It was discovered that the crystalline carbonates were mainly developed in the shale layer and were formed from the late-filling effects of the diagenetic cracks along the shale fissility planes; shale layers with crystalline carbonates are usually favorable for shale oil reserves. The micritic carbonates were formed from direct deposition controlled by biological effects in the stratified flows of the seasonal lake basins and are unfavorable for shale oil reserves.
•The laminar carbonates in organic-rich shale layers could be categorized crystalline and micritic carbonates.•The main factor controlling on crystalline carbonates is diagenetic fluids.•The micritic carbonates were formed from direct deposition controlled by biological effects.•The crystalline carbonates in organic-rich shale layers could be favorable shale oil reservoir.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In human mutant BRAF melanoma cells, the stemness transcription factor FOXD3 is rapidly induced by inhibition of ERK1/2 signaling and mediates adaptive resistance to RAF inhibitors. However, the ...mechanism underlying ERK signaling control of FOXD3 expression remains unknown. Here we show that SOX10 is both necessary and sufficient for RAF inhibitor-induced expression of FOXD3 in mutant BRAF melanoma cells. SOX10 activates the transcription of FOXD3 by binding to a regulatory element in FOXD3 promoter. Phosphorylation of SOX10 by ERK inhibits its transcription activity toward multiple target genes by interfering with the sumoylation of SOX10 at K55, which is essential for its transcription activity. Finally, depletion of SOX10 sensitizes mutant BRAF melanoma cells to RAF inhibitors in vitro and in vivo. Thus, our work discovers a novel phosphorylation-dependent regulatory mechanism of SOX10 transcription activity and completes an ERK1/2/SOX10/FOXD3/ERBB3 axis that mediates adaptive resistance to RAF inhibitors in mutant BRAF melanoma cells.
•Quantitative AI model achieving uncertainty analysis and optimization of contradictory factors•The quantitative relationship of algae products with carbon dioxide source;•The impact of algae ...cultivation on the choice of jet fuel or biodiesel;•The impact of renewable energy utilization on total energy consumption
The purpose would discover the impacts of the contradictory factors in application of algae in CO2 sequestration with sustainable biofuel benefit. Based on LCA approach, the quantitively AI assessment model and approach have been established coupling upstream CO2 source and downstream algal product at the uniform algae level of Nannochloropsis oceanica, which would benefit for algae biofuel deliverables choice. The AI model investigated the effects of interaction factors on the energy consumption, including transportation distances with purification modes coupling with CO2 concentration in flue gas, lipid content with specific productivity coupling the nutrient supply, refining process with final products. Computational framework of AI model is classified into three sub-models, including CO2 capture and purification model, algae cultivation and harvesting model, refining process and biofuel product model. According to uncertainty analysis by AI model, the positive energy gains have been conducted at a wide range of lipid contents despite of jet biofuel or biodiesel coupling solar energy utilization and by-product of bioactive nutrients effects. Biodieselwet and HTL-HRJ jet biofuel performed the priorities in energy consumption in three pathways of jet biofuel and three pathways of biodiesels. The allocation analysis confirmed that algae biofuel will be promising in the direction of cultivating appropriate algae for the target biofuel product requirement and enhancing by-product recovery. The results would enhance the interests in both LCA and CO2 sequestration with sustainable biofuel benefit.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
