The Beaufort Gyre (BG), the largest Arctic Ocean freshwater reservoir, has drastically increased its liquid freshwater content by 40% in the past two decades. If released within a short period, the ...excess freshwater could potentially impact the large-scale ocean circulation by freshening the upper subpolar North Atlantic. Here, we track BG-sourced freshwater using passive tracers in a global ocean sea-ice model and show that this freshwater exited the Arctic mostly through the Canadian Arctic Archipelago, rather than Fram Strait, during an historical release event in 1983-1995. The Labrador Sea is the most affected region in the subpolar North Atlantic, with a freshening of 0.2 psu on the western shelves and 0.4 psu in the Labrador Current. Given that the present BG freshwater content anomaly is twice the historical analog studied here, the impact of a future rapid release on Labrador Sea salinity could be significant, easily exceeding similar fluxes from Greenland meltwater.
Recent progress in understanding Beaufort Gyre (BG) dynamics reveals an important role of ice‐ocean stress in stabilizing BG freshwater content (FWC) over seasonal to interannual timescales. But how ...the BG's stratification and FWC respond to surface forcing over decadal timescales has not been fully explored. Using a global ocean‐sea ice model, we partition the BG into upper, middle (halocline), and lower (thermocline) layers and perform a volume budget analysis over 1948–2017. We find that the BG's asymmetric geometry (with steep and tight isohalines over continental slopes relative to the deep basin) is key in determining the mean volume transport balance. We further find that a net Ekman suction during 1983–1995 causes the upper and middle layers to deflate isopycnally, while an enhanced Ekman pumping during 1996–2017 causes these layers to inflate both isopycnally and diapycnally, the latter via anomalous flux from the upper to the middle layer.
Plain Language Summary
The Beaufort Gyre (BG) has increased its liquid freshwater content (FWC) by 40% in the past two decades. If released and transported downstream to the subpolar North Atlantic Ocean, the excess water might affect the ocean circulation via suppression of deep‐water formation. However, which layer is responsible for BG freshwater accumulations and releases over decadal timescales and the corresponding physical processes remain unclear, hampering our attempts to make future predictions. Here we use an ocean‐sea ice model to explore such changes in its three characteristic layers (upper mixed‐layer water, Pacific Water in the middle layer, and Atlantic Water in the lower layer). We find that the asymmetry of the BG, which has been simplified as a symmetric bowl shape in most previous studies, is important in determining the BG's layered mean state. Over decadal timescales, changes in BG volume are controlled by annual‐mean Ekman pumping/suction resulting from combined wind and ice‐ocean stresses. This study emphasizes the role of asymmetric geometry in determining the BG mean volume balance. It also explores the role of mean flow across the gyre's lateral boundaries in regulating BG's volume and FWC over decadal timescales.
Key Points
The Beaufort Gyre's asymmetric geometry is the key to explain a net mean lateral outflow in the upper layer, despite Ekman convergence
In the mean, the Gyre is fed by a northeast inflow into its middle layer, with outflow to its southwest from both upper and middle layers
Deflation/inflation processes are asymmetric in response to anomalous Ekman suction/pumping on decadal timescales
Through the preparation method, super-wetting property and its application in emulsion separation, it provides comprehensive insights about the copper-based superhydrophobic microfiltration membrane, ...thereby inducing a new emulsion separation mechanism, and demonstrating an efficient oil-in-water emulsion separation function performance.
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•The as-prepared membrane has extremely high separation efficiency (above 99.975%).•Copper-based microfiltration membranes expand the choice of materials for efficient separation of water-in-oil emulsions.•The inorganic binder aluminum phosphate was used to enhance the mechanical properties.•Rapidly self-assemble surface modification octadecanethiol (ODT) is the basis for reversible repair.
The micro-/nanohierarchical super-wetting filter materials with low energy consumption, low-cost and high-efficiency have attracted tremendous attention. Moreover, traditional emulsion separation materials based on micro-/nanohierarchical structure are easy to be irreversibly damaged due to poor mechanical properties. In this work, a copper-based superhydrophobic microfiltration membrane was fabricated based on simple spraying process and short time self-assemble surface modification method. Only driven by gravity, the membranes maintained excellent water-in-oil emulsion separation performance with the efficiency higher than 99.975%, even after 10 separation cycles, the efficiency is still higher than 99.95%. After 50 sandpaper abrasion cycles, the membranes still displayed excellent separation efficiency through a simple re-modification process. The superhydrophobic microfiltration membranes also had the ability to resist acid and alkali. Robust and copper-based superhydrophobic microfiltration membranes with reversible repair property provide new ideas for the selection of stable emulsion separation materials, and have more advantages and potentials in practical applications.
Spontaneous solid-state fermentation (SSF) of Chinese Baijiu involves diverse microbes from Daqu and pit mud (PM). Given that the transfer of interphase microflora during the fermentation is a ...continuous and dynamic process, longitudinal studies are essential to provide ecological insights into community stability and response to consecutive disturbances in the process. In this context, this study aimed to generate a comprehensive longitudinal characterization of the microbiota during the fermentation processes of Chinese strong-flavor Baijiu (CSFB) differing in cellar ages with consideration for potential relation to physicochemical variables. The microecology variations observed during the 6-years cellar SSF (SCSSF) and 30-years cellar SSF (TCSSF) processes reveal that fungal composition contributes to a larger extent than bacterial composition to such variations. Orders of
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dominated (average relative abundances >10%) the microbiota in both SCSSF and TCSSF processes but with a different percentage in the operational taxonomic unit (out) abundances. Compared with the SCSSF process, TCSSF possessed slower microbial succession rates, which were in accordance with the profile of physicochemical properties. From a network perspective, the microbial community structure observed in the TCSSF processes was more stable than that in the SCSSF. This may benefit from the milder physicochemical conditions of the TCSSF processes, especially the temperature, which is also more beneficial to the growth of some groups that have negative effects on fermentation, such as
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.
Cyperi Rhizoma
(CR) is the dry rhizome of
Cyperus rotundus
L., a Cyperaceae plant. It has a long history of clinical medication and is known as the “holy medicine” of gynecology. CR smells sweet and ...bitter. It has the effect of soothing the liver and relieving depression, regulating qi, regulating meridian and relieving pain. It can be used to treat liver qi stagnation, chest pain, spleen and stomach qi stagnation, hernia pain, irregular menstruation and other diseases. At present, the main chemical constituents isolated from CR are volatile oil, flavonoids and terpenes. Modern pharmacological studies have shown that CR has a wide range of pharmacological activities, including antidepressant, hypoglycemic, antioxidant, anti-inflammatory, antipyretic and analgesic effects. In this paper, the botany, traditional application, phytochemistry, pharmacological effects, processing and other aspects of CR are reviewed. At the same time, the shortcomings of current research of CR are discussed in depth, and the possible solutions are put forward in order to find a breakthrough point for future research of CR.
Nonmetallic co-doping and surface hole construction are simple and efficient strategies for improving the photocatalytic activity and regulating the electronic structure of g-C3N4. Here, the g-C3N4 ...catalysts with B-F or B-S co-doping combined with nitrogen vacancies (Nv) are designed. Compared to the pristine g-C3N4, the direction of the excited electron orbit for the B-F-co-doped system is more matching (N2pz→C2pz), facilitating the separation of electrons and holes. Simultaneously, the introduced nitrogen vacancy can further reduce the bandgap by generating impurity states, thus improving the utilization rate of visible light. The doped S atoms can also narrow the bandgap of the B-S-Nv-co-doped g-C3N4, which originates from the p-orbital hybridization between C, N, and S atoms, and the impurity states are generated by the introduction of N vacancies. The doping of B-F-Nv and B-S-Nv exhibits a better CO2 reduction activity with a reduced barrier for the rate-determining step of around 0.2 eV compared to g-C3N4. By changing F to S, the origin of the rate-determining step varies from *CO2→*COOH to *HCHO→*OCH3, which eventually leads to different products of CH3OH and CH4, respectively.
•A low-permeability layer (LPL) may reduce the size and increase the frequency of salt fingers associated with the unstable upper saline plume in coastal aquifers.•The LPL can trap the land-sourced ...solute and thereby prolong the solute residence time and the solute discharge duration.•The LPL may reduce the maximal solute efflux and the width of the solute discharge zone across the aquifer-ocean interface.•The solute plume is more horizontally stretched and spreads over a smaller cross-sectional area under the effect of the LPL.
The tide-induced upper saline plume (USP) in coastal aquifers plays a critical role in affecting the fate of land-sourced solutes. Early studies focused primarily on a quasi-steady USP, namely the size and salinity distributions of the plume remain unchanged over consecutive tidal cycles. In certain situations, the USP may become unstable. However, the effects of a low-permeability layer (LPL) on the pattern of fingering flow and land-sourced solute transport in coastal aquifers have not been examined. This problem was addressed numerically based on a 2-D cross-section of a tide-influenced layered coastal aquifer. The results reveal that the LPL can significantly reduce the size and accelerate the formation of salt fingers associated with the unstable USP. Compared with the homogeneous case, the maximum solute discharge rate and the width of discharge zone are decreased by the presence of the LPL, and the solute plume is stretched horizontally and squeezed vertically. Salt fingers may force part of the solute plume into the LPL, leading to an extended solute discharge duration. A sensitivity analysis shows that variations of the hydraulic conductivity, thickness and elevation of the LPL would greatly alter land-sourced solute transport. The trapped solute mass in the LPL, the maximum discharge rate and the residence time of the solute plume are more sensitive to the hydraulic conductivity and elevation than to the thickness of the LPL. These results have important implications for improving our understanding of flow and solute transport in layered coastal aquifers with an unstable USP.
Ganglioside GM3 is one of the most common membrane-bound glycosphingolipids. The over-expression of GM3 on tumor cells makes it defined as a tumor-associated carbohydrate antigen (TACA). The specific ...expression property in cancers, especially in melanoma, make it become an important target to develop anticancer vaccines or immunotherapies. However, in the manner akin to most TACAs, GM3 is an autoantigen facing with problems of low immunogenicity and easily inducing immunotolerance, which means itself only cannot elicit a powerful enough immune response to prevent or treat cancer. With a comparative understanding of the mechanisms that how immune system responses to the carbohydrate vaccines, this review summarizes the studies on the recent efforts to development GM3-based anticancer vaccines.
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•GM3 represents a promising target for the development of anticancer vaccines.•Strategies to enhance the immunogenicity and antigenicity of GM3 are reviewed.•Chemical modifications and structural analogs are avenues to improve GM3 vaccine.•Glycoengineering paves new frontiers for GM3 vaccine development.
Due to the dual air‐gap topology of the direct‐drive permanent magnet motor with inner enhance force (IEF‐DDPMM), the radial EM exciting force generated in the inner and outer air gaps when the rotor ...is eccentric will act on the same rotor, and the unbalanced magnetic pull (UMP) on the rotor will reduce the fatigue life of the rotor structure and bring many problems such as vibration and noise. Therefore, the rotor UMP compensation method of IEF‐DDPMM based on modular winding d‐axis current injection is proposed to suppress the harm caused by eccentricity. The expression of electromagnetic (EM) exciting force considering the cogging effect and current time harmonic without rotor eccentricity faults is derived by the analytical method. Also, the EM exciting force newly introduced due to the rotor eccentricity is analysed. The effects of different eccentricity types on torque characteristics, the fatigue life of the rotor structure and stator vibration of IEF‐DDPMM are compared and analysed by the FEM. Finally, the IEF‐DDPMM rotor eccentricity models are optimised based on the method. The performance of the motor before and after rotor UMP compensation is evaluated by FEM. The results show that the proposed method is correct and effective.
Current studies have shown that the spatial‐temporal graph convolutional network (ST‐GCN) is effective for skeleton‐based action recognition. However, for the existing ST‐GCN‐based methods, their ...temporal kernel size is usually fixed over all layers, which makes them cannot fully exploit the temporal dependency between discontinuous frames and different sequence lengths. Besides, most of these methods use average pooling to obtain global graph feature from vertex features, resulting in losing much fine‐grained information for action classification. To address these issues, in this work, the authors propose a novel spatial attentive and temporal dilated graph convolutional network (SATD‐GCN). It contains two important components, that is, a spatial attention pooling module (SAP) and a temporal dilated graph convolution module (TDGC). Specifically, the SAP module can select the human body joints which are beneficial for action recognition by a self‐attention mechanism and alleviates the influence of data redundancy and noise. The TDGC module can effectively extract the temporal features at different time scales, which is useful to improve the temporal perception field and enhance the robustness of the model to different motion speed and sequence length. Importantly, both the SAP module and the TDGC module can be easily integrated into the ST‐GCN‐based models, and significantly improve their performance. Extensive experiments on two large‐scale benchmark datasets, that is, NTU‐RGB + D and Kinetics‐Skeleton, demonstrate that the authors’ method achieves the state‐of‐the‐art performance for skeleton‐based action recognition.
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