With the advancements in wind turbine technologies, the cost of wind energy has become competitive with other fuel-based generation resources. Due to the price hike of fossil fuel and the concern of ...global warming, the development of wind power has rapidly progressed over the last decade. The annual growth rate has exceeded 26% since the 1990s. Many countries have set a goal for high penetration levels of wind generation. Recently, several large-scale wind generation projects have been implemented all over the world. It is economically beneficial to integrate very large amounts of wind capacity in power systems. Unlike other traditional generation facilities, using wind turbines presents technical challenges in producing continuous and controllable electric power. A distinct feature of wind energy is its nature of being ldquointermittent.rdquo Since it is difficult to predict and control the output of wind generation, its potential impacts on the electric grid are different from the traditional energy sources. At a high penetration level, an extrafast response reserve capacity is needed to cover the shortfall of generation when a sudden deficit of wind takes place. To enable a proper management of the uncertainty, this paper presents an approach to make wind power become a more reliable source on both energy and capacity by using energy storage devices. Combining the wind power generation system with energy storage will reduce fluctuation of wind power. Since it requires capital investment for the storage system, it is important to estimate the reasonable storage capacities for the desired applications. In addition, an energy storage application for reducing the output variation during the gust wind is also studied.
•Adding carbon-based materials on enhancement of AD performance were reviewed.•Carbon materials with positive/negative impacts to AD performance was illustrated.•Proposed mechanisms were ...reviewed.•Further research needs for adding carbon-based material strategy were discussed.
The anaerobic digestion is the adopted to remediate the pollutant and extract the bioenergy from the waste during the treatment. Effects of adding carbon-based materials on enhancement of digestion performance are studied in literature. This paper provided a mini review on the current research efforts on the traditional view on the cytotoxicity of carbon-based materials to the aquatic microorganisms and the novel “adding carbon-based material strategy” for improving the anaerobic digestion performances. The further research needs for comprehending the interactions between the added carbon materials, the substrates and the microorganisms and the impacts of adopting these additives on full-scale operations were highlighted.
Critical‐sized bone defects, especially for irregular shapes, remain a significant challenge in orthopedics. Although various biomaterials are developed for bone regeneration, their application for ...repair of irregular bone defects is limited by the complicated preparation procedures involved, and their lack of shape‐adaptive capacity, physiological adhesion, and potent osteogenic bioactivity. In the present study, a simple strategy of precipitation by introducing tannic acid (TA) with abundant phenolic hydroxyl groups and Fe3O4 nanoparticles, as metal‐phenolic networks (MPN), is developed to easily prepare a fast gelling, shape‐adaptive, and highly adhesive regenerated silk fibroin (RSF)/TA/Fe3O4 hydrogel system that can respond to a static magnetic field (SMF). The RSF/TA/Fe3O4 hydrogel exhibits sufficient adhesion in biological microenvironments and good osteogenic effect in vitro and in vivo, under an external SMF, and thus, can be applied to repair critical‐sized bone defects. Moreover, bioinformatics analysis reveals that the synergistic mechanism of Fe3O4 NPs and SMF on osteogenic effects can be promotion of osteoblast differentiation via activation of the cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG)/extracellular signal‐regulated kinase (ERK) signaling pathway. This study provides a promising biomaterial with potential clinical application for the future treatment of (irregular) critical‐sized bone defects.
A novel precipitation‐based strategy is proposed to fabricate the fast‐gelling, highly adhesive, and magnetic‐regenerated silk fibroin/tannic acid/Fe3O4 hydrogel with metal‐phenolic networks. The resulting hydrogel exhibits well capacity for promoting osteogenic differentiation and bone regeneration under the static magnetic field, which is a promising tissue engineering biomaterial for the repair of irregular bone defects.
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•Gold nanoparticles and zeolitic imidazolate framework-8 nanocomposites (Au@ZIF-8) were synthesized.•Au@ZIF-8/GCE possessed an excellent electrochemical performance to dopamine.•The ...proposed sensor exhibited acceptable stability and repeatability.
Gold nanoparticles and zeolitic imidazolate framework-8 nanocomposites (Au@ZIF-8) were synthesized through a simple hydrothermal method and used as an enzyme-free sensor for dopamine detection. Various characterizations were used to investigate the structure and morphology of Au@ZIF-8 nanocomposites. The electrochemical performance of Au@ZIF-8 nanocomposite modified glassy carbon electrode (Au@ZIF-8/GCE) was examined in 0.1 M phosphate-buffered saline with different concentrations of dopamine. Consequently, Au@ZIF-8/GCE possessed an excellent electrochemical catalytic performance to dopamine, having been reported to its wider linear range from 0.1 to 50 μM, lower detection limit of 0.01 μM (S/N = 3) and higher sensitivity of 6.452 μA mM−1 cm−2. The proposed sensor exhibited acceptable stability and repeatability due to the coupling effect of Au nanoparticles and ZIF-8. All the evidence suggested a potential application of Au@ZIF-8 nanocomposites in a non-enzymatic dopamine sensor.
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•Nickel hydroxide is regarded as a great potential urea oxidation reaction (UOR) electrocatalyst.•Various strategies, such as morphological design, heteroatom doping, surface vacancy ...is summarized.•The challenges and outlooks of utilizing nickel hydroxide for efficient UOR are discussed.
Nickel hydroxide (Ni(OH)2) are promising catalysts for efficient urea oxidation reactions (UOR), which can address the energy and environmental concerns associated with urea-containing wastewater. In addition to their low thermodynamic potential, this reaction can be used for energy-saving hydrogen production instead of the traditional oxygen evolution reaction. However, the sluggish kinetics and complex six-electron transfer process severely hamper the electrocatalytic performance of Ni(OH)2 electrocatalysts. To overcome those challenges, various strategies such as morphological design, heteroatom doping, surface vacancy, heterostructure, and supporting materials for Ni(OH)2 in UOR have been explored. This comprehensive summary highlights the significant research efforts in utilizing Ni(OH)2 for urea electrooxidation. The current challenges and prospects of Ni(OH)2 in UOR are also discussed, aiming to inspire further exploration in achieving efficient urea conversion.
Object detection in unmanned aerial vehicle (UAV) images is an extremely challenging task and involves problems such as multi-scale objects, a high proportion of small objects, and high overlap ...between objects. To address these issues, first, we design a Vectorized Intersection Over Union (VIOU) loss based on YOLOv5s. This loss uses the width and height of the bounding box as a vector to construct a cosine function that corresponds to the size of the box and the aspect ratio and directly compares the center point value of the box to improve the accuracy of the bounding box regression. Second, we propose a Progressive Feature Fusion Network (PFFN) that addresses the issue of insufficient semantic extraction of shallow features by Panet. This allows each node of the network to fuse semantic information from deep layers with features from the current layer, thus significantly improving the detection ability of small objects in multi-scale scenes. Finally, we propose an Asymmetric Decoupled (AD) head, which separates the classification network from the regression network and improves the classification and regression capabilities of the network. Our proposed method results in significant improvements on two benchmark datasets compared to YOLOv5s. On the VisDrone 2019 dataset, the performance increased by 9.7% from 34.9% to 44.6%, and on the DOTA dataset, the performance increased by 2.1%.
Cathode interfacial material (CIM) is critical to improving the power conversion efficiency (PCE) and long‐term stability of an organic photovoltaic cell that utilizes a high work function cathode. ...In this contribution, a novel CIM is reported through an effective and yet simple combination of triarylphosphine oxide with a 1,10‐phenanthrolinyl unit. The resulting CIM possesses easy synthesis and purification, a high T
g of 116 °C and attractive electron‐transport properties. The characterization of photovoltaic devices involving Ag or Al cathodes shows that this thermally deposited interlayer can considerably improve the PCE, due largely to a simultaneous increase in V
oc and FF relative to the reference devices without a CIM. Notably, a PCE of 7.51% is obtained for the CIM/Ag device utilizing the active layer PTB7:PC71BM, which far exceeds that of the reference Ag device and compares well to that of the Ca/Al device. The PCE is further increased to 8.56% for the CIM/Al device (with J
sc = 16.81 mA cm−2, V
oc = 0.75 V, FF = 0.68). Ultraviolet photoemission spectroscopy studies reveal that this promising CIM can significantly lower the work function of the Ag metal as well as ITO and HOPG, and facilitate electron extraction in OPV devices.
The organic molecule Phen‐NaDPO that possesses characteristics of a facile synthesis/purification, a high T
g, and attactive electron transport, is successfully shown as an promising cathode interlayer to improve the PCE. Consequently, a PCE of 7.5% and 8.56% is reported respectively for Phen‐NaDPO/Ag and Phen‐NaDPO/Al devices utilizing PTB7:PC71BM active layer, which compares well with that of the Ca/Al device.
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•Bimetallic cobalt-nickel supported on carbon fiber was synthesized by a straightforward homogeneous co-precipitation approach.•The modified Co-Ni@CF electrode demonstrated excellent ...electrooxidation activity toward dopamine (DA) and hydroquinone (HQ) without any other activating treatments.•The Co-Ni@CF electrode also performed good long-term stability and reproducibility.
Bimetallic cobalt-nickel supported on carbon fiber (Co-Ni@CF) was synthesized by a straightforward homogeneous co-precipitation approach. Electrochemical results demonstrated that the modified Co-Ni@CF electrode demonstrated excellent electrooxidation activity toward dopamine (DA) and hydroquinone (HQ) without any other activating treatments, which could be modified as an electrochemical biosensor for DA and HQ detection simultaneously. The as-proposed biosensor was developed for simultaneous detection of DA and HQ, featuring low detection limits (LODs) of 0.4698 μM for DA and 0.2388 mM for HQ, respectively. The sensor also offers broad linear ranges for DA (5.0-30 μM), and HQ (0.5-5.0 mM). Along with these attractive features, the Co-Ni@CF electrode also performed good long-term stability and reproducibility, making it a promising candidate for electrochemical biosensing of DA and HQ.
Type 2 diabetes is a major health problem worldwide, and one of its key features is the inability of elevated glucose to stimulate the release of sufficient amounts of insulin from pancreatic beta ...cells to maintain normal blood glucose levels. New therapeutic strategies to improve beta cell function are therefore believed to be beneficial. Here we demonstrate that the short-chain fatty acid receptors FFA2 (encoded by FFAR2) and FFA3 (encoded by FFAR3) are expressed in mouse and human pancreatic beta cells and mediate an inhibition of insulin secretion by coupling to Gi-type G proteins. We also provide evidence that mice with dietary-induced obesity and type 2 diabetes, as compared to non-obese control mice, have increased local formation by pancreatic islets of acetate, an endogenous agonist of FFA2 and FFA3, as well as increased systemic levels. This elevation may contribute to the insufficient capacity of beta cells to respond to hyperglycemia in obese states. Indeed, we found that genetic deletion of both receptors, either on the whole-body level or specifically in pancreatic beta cells, leads to greater insulin secretion and a profound improvement of glucose tolerance when mice are on a high-fat diet compared to controls. On the other hand, deletion of Ffar2 and Ffar3 in intestinal cells did not alter glucose tolerance in diabetic animals, suggesting these receptors act in a cell-autonomous manner in beta cells to regulate insulin secretion. In summary, under diabetic conditions elevated acetate acts on FFA2 and FFA3 to inhibit proper glucose-stimulated insulin secretion, and we expect antagonists of FFA2 and FFA3 to improve insulin secretion in type 2 diabetes.
Tumor cells trends to express high level of pyruvate kinase M2 (PKM2). The inhibition of PKM2 activity is needed for antioxidant response by diverting glucose flux into the pentose phosphate pathway ...and thus generating sufficient reducing potential. Here we report that PKM2 is succinylated at lysine 498 (K498) and succinylation increases its activity. SIRT5 binds to, desuccinylates and inhibits PKM2 activity. Increased level of reactive oxygen species (ROS) decreases both the succinylation and activity of PKM2 by increasing its binding to SIRT5. Substitution of endogenous PKM2 with a succinylation mimetic mutant K498E decreases cellular NADPH production and inhibits cell proliferation and tumor growth. Moreover, inhibition of SIRT5 suppresses tumor cell proliferation through desuccinylation of PKM2 K498. These results reveal a new mechanism of PKM2 modification, a new function of SIRT5 in response to oxidative stress which stimulates cell proliferation and tumor growth, and also a potential target for clinical cancer research.
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