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Abstract The impact of interbasin linkage on the weather/climate and ecosystems is significantly broader and profounder than that of only appearing in an individual basin. Here, we reveal that a decadal linkage of sea surface temperature (SST) has emerged between western Australian coast and western–central tropical Pacific since 1985, associated with continuous intensification of decadal variabilities (8–16 years). The rapid SST changes in both tropical Indian Ocean and Indo-Pacific warm pool in association to greenhouse gases and volcanoes are emerging factors resulting in enhanced decadal co-variabilities between these two regions since 1985. These SST changes induce enhanced convection variability over the Maritime Continent, leading to stronger easterlies in the western–central tropical Pacific during the warm phase off western Australian coast. The above changes bring about cooling in the western–central tropical Pacific and strengthened Leeuwin Current and anomalous cyclonic wind off western Australian coast, and ultimately resulting in enhanced coupling between these two regions. Our results suggest that enhanced decadal interbasin connections can offer further understanding of decadal changes under future warmer conditions.

In recent years, 3D hydrogels based on alginate (Alg) have undergone substantial advancements, holding transformative potential for biomedicine and regenerative medicine. Nevertheless, the viscosity of Alg needs to be further increased, in order to print complex 3D structures. Attempts to adjust printability often employ rheological modifiers like methylcellulose (MC), but these still lack mechanical integrity for broader biomedical applications. Our study sought to chemically modify Alg/MC to create a photopolymerizable hydrogel by incorporating acrylate-based monomers, which would enhance the curing ability of the base hydrogel, leading to better mechanical properties of Alg/MC, such as stretchability and stability with shape recovery. Comprehensive mechanical assessments unveiled remarkable tensile properties, achieving a notable specific strength benchmark of 44.72 kPa/(g.cm-3) before reaching the point of fracture. This represents a substantial 250 % improvement compared to samples lacking the acrylate monomer. Biomedical assessments confirmed the hydrogel's promising potential, especially with the MG-63 cell line, underscoring its suitability for advanced applications like tissue engineering.

Abstract Lymph node (LN) metastasis is one of the predominant metastatic routes of non-small cell lung cancer (NSCLC) and is considered as a leading cause for the unsatisfactory prognosis of patients. Although lymphangiogenesis is well-recognized as a crucial process in mediating LN metastasis, the regulatory mechanism involving lymphangiogenesis and LN metastasis in NSCLC remains unclear. In this study, we employed high-throughput sequencing to identify a novel circular RNA (circRNA), circTLCD4-RWDD3, which was significantly upregulated in extracellular vesicles (EVs) from LN metastatic NSCLC and was positively associated with deteriorated OS and DFS of patients with NSCLC from multicenter clinical cohort. Downregulating the expression of EV-packaged circTLCD4-RWDD3 inhibited lymphangiogenesis and LN metastasis of NSCLC both in vitro and in vivo. Mechanically, circTLCD4-RWDD3 physically interacted with hnRNPA2B1 and mediated the SUMO2 modification at K108 residue of hnRNPA2B1 by upregulating UBC9. Subsequently, circTLCD4-RWDD3-induced SUMOylated hnRNPA2B1 was recognized by the SUMO interaction motif (SIM) of ALIX and activated ALIX to recruit ESCRT-III, thereby facilitating the sorting of circTLCD4-RWDD3 into NSCLC cell-derived EVs. Moreover, EV-packaged circTLCD4-RWDD3 was internalized by lymphatic endothelial cells to activate the transcription of PROX1, resulting in the lymphangiogenesis and LN metastasis of NSCLC. Importantly, blocking EV-mediated transmission of circTLCD4-RWDD3 via mutating SIM in ALIX or K108 residue of hnRNPA2B1 inhibited the lymphangiogenesis and LN metastasis of NSCLC in vivo. Our findings reveal a precise mechanism underlying SUMOylated hnRNPA2B1-induced EV packaging of circTLCD4-RWDD3 in facilitating LN metastasis of NSCLC, suggesting that EV-packaged circTLCD4-RWDD3 could be a potential therapeutic target against LN metastatic NSCLC.

Abstract The Maritime Continent (MC), a critical region for inter‐basin climate interaction, harbors the world's highest marine biodiversity. Ocean warming in the MC, although with notable impacts on regional climate and marine ecosystems, remains poorly constrained by observations. By applying a volume‐correction algorithm to existing gridded observational data sets, this study provides an estimate for the ocean heat content (OHC) change of the MC. The results suggest a substantial OHC increase of 2.65 ± 0.46 Zettajoules during 1990–2015 (1.08 ± 0.17 W m−2) and limited changes before and after. This increase primarily arose from the enhanced Pacific Walker circulation, which drove a convergence of upper‐layer warm water toward the MC. A potential heat storage “hotspot” with enhanced warming below 500 m emerges within the Sulu Sea, which is supported by analysis of profile data collected in boreal winter but not in other seasons.

Abstract Background Circular RNAs (circRNAs) circularized by back-splicing of pre-mRNA are widely expressed and affected the proliferation, invasion and metastasis of bladder cancer (BCa). However, the mechanism underlying circRNA biogenesis in mediating the distant metastasis of BCa still unexplored. Methods RNA sequencing data between BCa and normal adjacent tissues was applied to identify the differentially expressed circRNAs. The functions of circNIPBL in BCa were investigated via a series of biochemical experiments. The Clinical significance of circNIPBL was examined in a cohort of larger BCa tissues. Results In the present study, we identified a novel circRNA (hsa_circ_0001472), circNIPBL, which was significantly upregulated and had great influence on the poor prognosis of patients with BCa. Functionally, circNIPBL promotes BCa metastasis in vitro and in vivo. Mechanistically, circNIPBL upregulate the expression of Wnt5a and activated the Wnt/β-catenin signaling pathway via directly sponged miR-16-2-3p, leading to the upregulation of ZEB1, which triggers the EMT of BCa. Moreover, we revealed that ZEB1 interacted with the flanking introns of exons 2–9 on NIPBL pre-mRNA to trigger circNIPBL biogenesis, thus forming a positive feedback loop. Importantly, circNIPBL overexpression significantly facilitated the distant metastasis of BCa in the orthotopic bladder cancer model, while silencing ZEB1 remarkably blocked the effects of metastasis induced by circNIPBL overexpression. Conclusions Our study highlights that circNIPBL-induced Wnt signaling pathway activation triggers ZEB1-mediated circNIPBL biogenesis, which forms a positive feedback loop via the circNIPBL/miR-16-2-3p/Wnt5a/ZEB1 axis, supporting circNIPBL as a novel therapeutic target and potential biomarker for BCa patients. Graphical Abstract

The Lombok Strait (LS), Ombai Strait (OS), and Timor Passage (TP) are three major outlets of the Indonesian Throughflow to the Indian Ocean. Here, sources and pathways of the LS, OS, and TP outflows are explored by a Lagrangian particle tracking analysis based on a ~3 km regional ocean model simulation. The Makassar Strait transport contributes to ~80%, ~75%, and ~45% of the LS, OS, and TP outflows, respectively. However, ~41% and ~19% of the TP and OS outflows stem from the Lifamatola Passage, which largely feeds the upper and intermediate layers of the outflows. The role of Karimata Strait is quite limited and restricted to the upper layer. It takes 1-2 years and 2-6 years for the Makassar Strait water to reach the OS and TP, respectively, whereas the Lifamatola Passage water passes through the OS (2-6 years) and TP (3-9 years) on a prolonged transit time. In the Banda Sea, the western boundary current is the main pathway toward the OS, while the waters to the TP tend to take a basin interior route.

Abstract The development of nano–manufacture technology in the twenty‐first century has paved the way for artificial nanostructure constructions like man–made superlattices, providing historical breakthroughs in thermal physics and thermoelectrics by the modulation of phonons. Still, high–performance thermal insulators haven't come into operation due to the arduousness, costing and unscalability of artificiality. Herein, intentional engineering on a so–called ‘natural superlattice’ with alternating PbSe– and Bi2Se3–layer crystal structure is brought forth to recreate the mechanism of artificial superlattices and boost phonon localization. The thermal conductivity notably shows a direction–specific reduction, leading to minimum approaching and enhanced anisotropy. The modification of the natural framework and its effects have been supported by various transport and structure studies. This work sets a generalizable example for natural layered material engineering that bridges between the inflexible, changeless but self–assembled natural layered compounds, and the highly efficient, delicately tailored but unscalable artificial superlattice complexes. The methodology promises new horizons for practicable thermal management.

IntroductionBiodiversity maintenance and its underlying mechanisms are central issues of ecology. However, predicting the composition turnovers of microbial communities at multiple spatial scales remains greatly challenging because they are obscured by the inconsistent impacts of climatic and local edaphic conditions on the assembly process.MethodsBased on the Illumina MiSeq 16S/18S rRNA sequencing technology, we investigated soil bacterial and eukaryotic communities in biocrusts with different successional levels at a subcontinental scale of Northern China.ResultsResults showed that irrespective of spatial scale, bacterial α diversity increased but eukaryotic diversity decreased with the primary succession, whereas both β diversities decreased at the subcontinental scale compared with smaller scales, indicating that the biogeographic pattern of soil microorganisms was balanced by successional convergence and distance decay effect. We found that the convergence of bacterial and eukaryotic communities was attributed to the turnovers of generalist and specialist species, respectively. In this process, edaphic and climatic factors showed unique roles in the changes of diversity at local/subcontinental scales. Moreover, the taxonomic diversity tended to be more susceptible to climatic and edaphic conditions, while biotic factors (photosynthesis and pigments) were more important to phylogenetic diversity.ConclusionTaken together, our study provided comprehensive insights into understanding the pattern of microbial diversity at multiple spatial scales of drylands.

Quantifying spatiotemporal characteristics of intraseasonal variability (ISV) of upper ocean (100 m) zonal currents ( U ) in the equatorial western Pacific remains difficult due to a lack of direct observations. Here we investigate the characteristics by analyzing five subsurface mooring data at 140°–142° E, 1.7° S–4.7° N, from January 2014 to April 2021. Our analysis revealed that U ISV has an amplitude exceeding 40 cm s ^−1 , comparable to their long-term mean, and pronounced seasonality, with a peaking period in boreal winter–spring (October–April) and a weakening period in summer–autumn (May–September). U ISV intensity in the south of the equator is 50% stronger than that in the north. Analysis of satellite/reanalysis data and model experiments suggests that atmospheric intraseasonal oscillation accounts for 80% of the U ISV seasonality through wind forcing, while the oceanic internal process contributes 20% through nonlinear baroclinic instability. The consistent variation in mixed layer depth indicates the potential roles of oceanic ISVs in seasonal phase locking of El Niño–Southern oscillation. Our results highlight the significance of direct observations for better understanding and estimating ISVs of ocean circulation.

The subduction of oceanic water masses provides a crucial pathway for anthropogenic heat to enter the subsurface ocean, thereby shaping deep-reaching warming signatures. Analyzing data from eight ocean and atmosphere reanalysis datasets, we show that the average annual subduction rate of the global ocean (excluding 10° S–10° N) is 312.4 ± 27.9 Sv, resulting in a mean heat transport of 20.2 ± 2.1 PW towards the subsurface ocean. This subduction-driven heat transport has exhibited an increase of 0.09 ± 0.08 PW/decade since 1970. The increase predominantly stems from the overall enhancement of subduction within the latitudes of 30° S–50° S, dictated by intensified westerly winds that lead to the deepening of the local mixed layer depth. Our findings underscore the essence of wind-driven changes in the Southern Ocean subduction, which wield considerable influence over the global climate by regulating the vertical transport of heat and carbon from the sea surface to the deep waters.

Abstract While the pivotal role of the Indonesian Throughflow (ITF) in the global ocean circulation and climate has been widely recognized, accurate estimation of its volume transport based on observational data remains challenging. This work provides an updated estimate of the monthly ITF geostrophic transport (ITFG) in the upper 700 m at the IX1 section between Indonesia and Australia. The ITFG estimate is better constrained by improved data correction and new salinity data products. The mean ITFG of 1993–2018 is 8.2 ± 0.2 Sv, in which contributions of the temperature and salinity components (ITFT and ITFS) are 5.5 ± 0.2 and 2.8 ± 0.1 Sv, respectively. The interannual variability (∼4.4 Sv in standard deviation) is dominated by ITFT, as the result of wind‐driven thermocline dynamics, and slightly attenuated in amplitude by ITFS. The strengthening trend of 1.33 Sv decade−1 during 1993–2018 primarily arises from ITFS and secondarily from ITFT.

Increased extreme high sea level events and concurrence of marine heatwaves are observed along the Indian Ocean coast of Indonesia in the past decade due to the combined impact of anthropogenic warming and natural decadal climate variability.

Spinal cord injury (SCI) is a serious refractory disease of the central nervous system (CNS), which mostly caused by high-energy trauma. Existing interventions such as hormone shock and surgery are insufficient options, which relate to the secondary inflammation and neuronal dysfunction. Hydrogel with neuron-protective behaviors attracts tremendous attention, and black phosphorus quantum dots (BPQDs) encapsulating with Epigallocatechin-3-gallate (EGCG) hydrogels (E@BP) is designed for inflammatory modulation and SCI treatment in this study. E@BP displays good stability, biocompatibility and safety profiles. E@BP incubation alleviates lipopolysaccharide (LPS)-induced inflammation of primary neurons and enhances neuronal regeneration in vitro. Furthermore, E@BP reconstructs structural versus functional integrity of spinal cord tracts, which promotes recovery of motor neuron function in SCI rats after transplantation. Importantly, E@BP restarts the cell cycle and induces nerve regeneration. Moreover, E@BP diminishes local inflammation of SCI tissues, characterized by reducing accumulation of astrocyte, microglia, macrophages, and oligodendrocytes. Indeed, a common underlying mechanism of E@BP regulating neural regenerative and inflammatory responses is to promote the phosphorylation of key proteins related to AKT signaling pathway. Together, E@BP probably repairs SCI by reducing inflammation and promoting neuronal regeneration via the AKT signaling pathway.

Abstract The intraseasonal variability of the intermediate water (IW) and its characteristics east of Taiwan are studied utilizing 17 months of long-term, continuous and synchronous measurements of temperature, salinity and current from mooring sites deployed at 122° E/23° N from January 2016 to May 2017. Direct measurements revealed water masses east of Taiwan alternately show complete South China Sea Intermediate Water or North Pacific Intermediate Water (NPIW) characteristics, mostly in a mixed state, with NPIW dominating 70% of the time. For the first time, it is demonstrated that the variation of IW with periods of ~ 80 days is mainly related to mesoscale eddies. Anticyclonic (cyclonic) eddies corresponding to an increase (decrease) in temperature and salinity in the intermediate layer. Further mechanism analysis indicates the vertical motion of the water mass inside the eddies is one of the reasons for the thermohaline change in the intermedaiter layer. In addition, the anticyclonic eddies may increase the salinity concentration gradient across the Luzon Strait, and the enhanced advection is favorable to the outflow of water masses in the South China Sea. When the cyclonic eddies acts on the eastern part of Taiwan, the influence of the northward advection is weakened and the southward flow on its left side is more favorable to the transport of NPIW.

Abstract The tropical Southeast Indian Ocean (SEIO) is a key area linking the global freshwater and heat exchanges. The Indian Ocean Dipole (IOD) fundamentally modulates the Indian Ocean circulation and thus regulates the basin‐wide freshwater balance. However, our knowledge of this effect remains limited. Using observational‐based data sets, this study suggests that extreme positive IOD events have notable signatures on the three‐dimensional freshwater content of the SEIO, leading to the vertically opposite salinity anomalies in the surface and subsurface layers. The wind changes led to the northwestward extension of the South Equatorial Current and intensified Sumatra‐Java upwelling. The changing horizontal and vertical currents jointly result in the complicated salinity anomalies. The Equatorial Undercurrent serves as the conduit for water exchange between the equator and the SEIO. This work highlights a strong coupling between the equatorial circulation and the three‐dimensional freshwater inventory of the SEIO within the framework of the IOD.

Abstract Multidecadal sea surface temperature covariance in the southern Atlantic and Indian Oceans within the 20°–45°S band (termed the SAIOs) has been detected, but the origins of these variations remain uncertain. This study focuses on the decade‐long warming surge (0.43°C/decade) during 1965–1975 and the stalled warming pace (0.05°C/decade) thereafter. Observations and models overall suggest the essence of external forcing in controlling the warming rates of these two periods. Specifically, the 1963 eruption of Mount Agung caused an abrupt cooling of the SAIO, and the recovery of radiative heating during the following decade led to rapid surface warming. The persistent positive trend of the Southern Annular Mode since the late‐1970s has retarded the SAIO warming, primarily by enhancing surface wind speed and latent heat release. Although internal variability can also affect the SAIO through atmospheric teleconnections, its role is overall secondary during the two periods.

The southeastern Indian Ocean (SEIO) exhibits prominent decadal variability in sea surface salinity (SSS), showing salinity decreases during 1995-2000 and 2005-2011 and increases during 2000-2005 and after 2011. These salinity changes are linked to the Indo-Pacific climate and have impacts on the regional marine environment. Yet, the underlying mechanism has not been firmly established. In this study, decadal SSS variability of the SEIO is successfully simulated by a high-resolution regional ocean model, and the mechanism is explored through a series of sensitivity experiments. The results suggest that freshwater transport of the Indonesian throughflow (ITF) and local precipitation are two major drivers for the SSS decadal variability. They mutually cause most of the variability, with a generally larger contribution of precipitation. Other processes, such as evaporation and advection driven by local winds, play a minor role. Further analysis shows that the decadal precipitation in the SEIO is mainly associated with the decadal variability of Ningaloo Niño. Ocean dynamic processes significantly modify the relationship between SSS and precipitation, greatly shortening their lag time. The changes in both volume transport and salinity of the ITF water can cause large salinity changes in the SEIO region. Although local wind forcing gives rise to considerable changes in evaporation rate and ocean current advection, its overall contribution to decadal SSS variability is small compared to local precipitation and the ITF.

Highlights Long-term injection of glucocorticoids in the knee joint cavity promotes loss of cartilage content. CD90-positive stem cell vesicles encapsulated with Triamcinolone acetonide-loaded nanoparticles have good materials. T-CD90@NPs drive anti-inflammatory properties and promote cartilage regeneration after osteoarthritis. T-CD90@NPs regulate the polarization of type 2 macrophages to resist inflammation. T-CD90@NPs promote chondrocyte regeneration through the FOXO signaling pathway.

Jet noise is a common problem in minimum quantity lubrication (MQL) technology. This should be given great attention because of its serious impacts on the physical and mental health of the operators. In this study, a micro-grooved nozzle is proposed based on the noise reduction concept of biological micro-grooves. The flow field and acoustic characteristics of an original nozzle and a micro-grooved nozzle were investigated numerically to help better understand the noise reduction mechanism. The reasons for noise generation and the effects of the length (L), width (W) and depth (δ) of the micro-grooves on noise reduction were analyzed. It was found that jet noise is generated by the large-scale vortex ring structure and the pressure fluctuations caused by its motion. The overall sound pressure level (OASPL) decreased with the increases in W and δ, and increased with the increase in L. Among of them, δ has the greatest effect on noise reduction. The maximum noise reduction achieved was 6.66 dB, as verified by the OASPL test. Finally, the noise reduction mechanism was discussed in terms of the flow field, vorticity and the frequency characteristics. Micro-grooves can enhance the mixing of airflow inside the nozzle and accelerate the process of large-scale vortices breaking into smaller-scale vortices. It also reduces the sound pressure level (SPL) of middle frequencies, as well as the SPL of high frequencies on specific angles.

Internet of Things (IoT) technology has permeated into all aspects of today’s society and is playing an increasingly important role. Identity authentication is crucial for IoT devices to access the network, because the open wireless transmission environment of the IoT may suffer from various forms of network attacks. The asymmetry in the comprehensive capabilities of gateways and terminals in the IoT poses significant challenges to reliability and security. Traditional encryption-based identity authentication methods are difficult to apply to IoT terminals with limited capabilities due to high algorithm complexity and low computational efficiency. This paper explores physical layer identity identification based on channel state information (CSI) and proposes an intelligent identification method based on deep reinforcement learning (DRL). Specifically, by analyzing and extracting the features of the real received CSI information and a setting low-complexity state, as well as action and reward parameters for the deep neural network of deep reinforcement learning oriented to the scenario, we obtained an authentication method that can efficiently identify identities. The validation of the proposed method using collected CSI data demonstrates that it has good convergence properties. Compared with several existing machine-learning-based identity recognition methods, the proposed method has higher recognition accuracy.

Background: A-kinase interacting protein 1 (AKIP1) is recently implicated in the pathogenesis of several solid tumors, while its role in glioblastoma multiforme (GBM) is largely unknown. Therefore, the current study aimed to investigate the effect of AKIP1 on GBM cell malignant behaviors, stemness, and its underlying molecular mechanisms. Methods: U-87 MG and A172 cells were transfected with control or AKIP1 overexpression plasmid; control or AKIP1 siRNA plasmid. Then cell proliferation, apoptosis, invasion, CD133+ cell proportion, and sphere formation assays were performed. Furthermore, RNA-Seq was performed in U-87 MG cells. Besides, AKIP1 expression was detected in 25 GBM and 25 low-grade glioma (LGG) tumor samples. Results: AKIP1 was increased in several GBM cell lines compared to the control cell line. After transfections, it was found that AKIP1 overexpression increased cell invasion, CD133+ cell proportion, and sphere formation ability while less affecting cell proliferation or cell apoptosis in U-87 MG and A172 cells. Moreover, AKIP1 siRNA achieved the opposite effect in these cells, except that it inhibited cell proliferation but induced cell apoptosis to some extent. Subsequent RNA-Seq assay showed several critical carcinogenetic pathways, such as PI3K/AKT, Notch, EGFR tyrosine kinase inhibitor resistance, Ras, ErbB, mTOR pathways, etc. were potentially related to the function of AKIP1 in U-87 MG cells. Clinically, AKIP1 expression was higher in GBM tissues than in LGG tissues, which was also correlated with the poor prognosis of GBM to some degree. Conclusions: AKIP1 regulates the malignant behaviors and stemness of GBM via regulating multiple carcinogenetic pathways.

Influenced by the topography, the spatial variation of soil thickness on karst slopes is very large, and accordingly the spatial variation of soil moisture is also large. Therefore, analyzing the spatial heterogeneity of soil moisture on hillslopes is important for maintaining ecosystem stability. Combining geostatistical methods and GIS technology, the spatial variability and distribution pattern of soil moisture and the influencing factors of spatial variation and surface soil moisture (0–7 cm) on a typical karst shrub–grass hillslope were analyzed. The results showed that the mean soil moisture and coefficient of variation (CV) ranged between 25.7–42.6% and 10.3–20.9%, respectively, showing a moderate variation. The soil moisture presented a moderate or strong spatial autocorrelation in the sampling scale. The occurrence of rainfall events can exert a great influence on reducing the spatial heterogeneity of soil moisture. The spatial distribution pattern of soil moisture showed roughly plaque or stripe distribution. When soil moisture was much lower, the patch space fragmentation of soil moisture was higher. The soil moisture was higher in the low and middle parts of the plot. We can conclude that factors such as topography, vegetation, and weather conditions will exert a significant effect on soil moisture spatial variability. Areas with lower slope and higher vegetation coverage were more conducive to the retention of soil moisture.

Abstract In the past decade (2010–2019), the annual maximum typhoon storm surge (AMTSS) accounted for 46.6% of the total direct economic loss caused by marine disasters in Chinese mainland, but its prediction in advance is challenging. By analyzing records of 23 tide-gauge stations, we found that the AMTSSs in Shanghai, Zhejiang and Fujian show significant positive correlations with the El Niño-Southern Oscillation (ENSO). For the 1987–2016 period, the maximum correlation is achieved at Pingtan station, where correlation coefficient between the AMTSS and Niño-3.4 is 0.55. The AMTSS occurring in El Niño years are stronger than those in non-El Niño years by 9–35 cm in these areas. Further analysis suggests that a developing El Niño can greatly modulate the behaviors of Northwest Pacific typhoons. Strong typhoons tend to make landfall in southeast China with stronger intensities and northward shifted landfall positions. This study indicates that the modulation effect by ENSO may provide potential predictability for the AMTSS, which is useful for the early alert and reduction of storm surge damages.

The maintenance and variation of the Pacific Equatorial Undercurrent (EUC) are thought to be controlled by the zonal pressure gradient force (ZPGF). However, a recent study found that a large-scale circulation associated with Rossby waves can also lead to EUC variation, implying that the structures and timing of the influential winds and the underlying wind-driven mechanisms need to be revisited. Here, we use the adjoint-sensitivity method to obtain the crucial winds that can most efficiently influence EUC variations. The obtained adjoint sensitivities (denoting the sensitive winds) are confined to 15°S–15°N and exhibit a funnel-shaped pattern with high symmetry about the equator. The remote winds, which occur 4 to 11 months prior, can lead to EUC variations at the basin scale; in contrast, the near-term winds (occurring not earlier than 4 months) lead only to local EUC variations. Accordingly, we find that wind-initiated equatorial Kelvin waves, equatorial Rossby waves, and the reflected waves at both the western and eastern boundaries superimpose onto each other to result in EUC variations. Specifically, when the travel time is longer than 4 months, the waves can form a negative-positive-negative sea surface height anomaly (SSHA) pattern between 15°S and 15°N in the central-eastern tropical Pacific, indicating the joint effect of both types of waves; they also form a positive SSHA in the western equatorial Pacific, indicating the dominance of the Kelvin wave therein. These mechanisms are complementary to the canonical ZPGF mechanism, which provide a clear theoretical basis for EUC variation studies.

Archaea exhibit strong community heterogeneity with microhabitat gradients and are a non-negligible part of biocrust’s microorganisms. The study on archaeal biogeography in biocrusts could provide new insights for its application in environmental restoration. However, only a few studies on assembly processes and co-occurrence patterns of the archaeal community in patchy biocrusts have been reported, especially considering the number of species pools (SPs). Here, we comprehensively collected biocrusts across 3,500 km of northern China. Different successional biocrusts from various regions contain information of local climate and microenvironments, which can shape multiple unique archaeal SPs. The archaeal community differences in the same successional stage exceeded the variations between successional stages, which was due to the fact that the heterogeneous taxa tended to exchange between unknown patches driven by drift. We also comparatively studied the driving forces of community heterogeneity across three to ten SPs, and assembly and co-occurrence patterns were systematically analyzed. The results revealed that the impact of spatial factors on biogeographic patterns was greater than that of environmental and successional factors and that impact decreased with the number of SPs considered. Meanwhile, community heterogeneity at the phylogenetic facet was more sensitive to these driving factors than the taxonomic facet. Subgroups 1 (SG1) and 2 (SG2) of the archaeal communities in biocrusts were dominated by Nitrososphaeraceae and Haloarchaea, respectively. The former distribution pattern was associated with non-salinity-related variables and primarily assembled by drift, whereas the latter was associated with salinity-related variables and primarily assembled by homogeneous selection. Finally, network analysis indicated that the SG1 network had a higher proportion of competition and key taxa than the SG2 network, but the network of SG2 was more complex. Our study suggested that the development of the archaeal community was not consistent with biocrusts succession. The dominant taxa may determine the patterns of community biogeography, assembly, and co-occurrence.

Abstract Biocrusts play critical eco-functions in many drylands, however it is challenging to explore their community assembly, particularly within patched successional types and across climate zones. Here, different successional biocrusts (alga, lichen, and moss-dominated biocrusts) were collected across the northern China, and assembly of biocrust microbial communities was investigated by high-throughput sequencing combined with measurements of soil properties and microclimate environments. Bacterial and eukaryotic communities showed that the maximum and minimum community variation occurred across longitude and latitude, respectively. In the regions where all three stages of biocrusts were involved, the highest community difference existed between successional stages, and decreased with distance. The community assembly was generally driven by dispersal limitation, although neutral processes have controlled the eukaryotic community assembly in hyperarid areas. Along the succession, bacterial community had no obvious patterns, but eukaryotic community showed increasing homogeneity, with increased species sorting and decreased dispersal limitation for community assembly. Compared to early successional biocrusts, there were higher microbial mutual exclusions and more complex networks at later stages, with distinct topological features. Correlation analysis further indicated that the balance between deterministic and stochastic processes might be mediated by aridity, salinity, and total phosphorus, although the mediations were opposite for bacteria and eukaryotes.

The Agulhas retroflection (AR) region possesses the highest eddy kinetic energy (EKE) level in the Indian Ocean. However, mechanisms regulating EKE of the AR remain uncertain. Here, by analyzing an eddy-resolving coupled model simulation with improved EKE representation, we show that the upper-ocean EKE of the AR is mainly generated through barotropic instability in its upstream and leakage zones and is by nonlocal transport in its downstream zone. The interaction between mesoscale eddies and local winds plays a key role in EKE dissipation. The lack of eddy-wind interaction results in flawed EKE budget in the leakage zone in ocean-alone models, leading to severe biases in EKE distribution with overestimation and over-strong penetration into the South Atlantic. Our results highlight the essence of mesoscale air-sea interaction in the dynamics of the AR, with implications for understanding the inter-basin transport of the Agulhas leakage.

Summary: As a biological pump, the heart needs to consume a substantial amount of energy to maintain sustained beating. Myocardial energy metabolism was recently reported to be related to the loss of proliferative capacity in cardiomyocytes (CMs). However, the intrinsic relationship between beating rate and proliferation in CMs and whether energy metabolism can regulate this relationship remains unclear. In this study, we find that moderate heart rate reduction (HRR) induces CM proliferation under physiological conditions and promotes cardiac regenerative repair after myocardial injury. Mechanistically, moderate HRR induces G1/S transition and increases the expression of glycolytic enzymes in CMs. Furthermore, moderate HRR induces a metabolic pattern switch, activating glucose metabolism and increasing the relative proportion of ATP production by the glycolytic pathway for biosynthesis of substrates needed for proliferative CMs. These results highlight the potential therapeutic role of HRR in not only acute myocardial protection but also long-term CM restoration.

Mesoscale sea surface temperature (SST) variability triggers mesoscale air–sea interactions and is linked to ocean subsurface mesoscale dynamics. The National Oceanic and Atmospheric Administration (NOAA) daily Optimum Interpolation SST (OISST) products, based on various satellite and in situ SST data, are widely utilized in the investigation of multi-scale SST variabilities and reconstruction of subsurface and deep-ocean fields. The quality of OISST datasets is subjected to temporal inhomogeneity due to alterations in the merged data. Yet, whether this issue can significantly affect mesoscale SST variability is unknown. The analysis of this study detects an abrupt enhancement of mesoscale SST variability after 2007 in the OISST-AVHRR-only version 2 and version 2.1 datasets (hereafter OI.v2-AVHRR-only and OI.v2.1-AVHRR-only). The contrast is most stark in the subtropical western boundary current (WBC) regions, where the average mesoscale SST variance during 2007–2018 is twofold larger than that during 1993–2006. Further comparisons with other satellite SST datasets (TMI, AMSR-E, and WindSAT) suggest that the OISST-AVHRR-only datasets have severely underestimated mesoscale SST variability before 2007. An evaluation of related documents of the OISST data indicates that this bias is mainly caused by the change of satellite AVHRR instrument in 2007. There are no corresponding changes detected in the associated fields, such as the number and activity of mesoscale eddies or the background SST gradient in these regions, confirming that the underestimation of mesoscale SST variability before 2007 is an artifact. Another OISST product, OI.v2-AVHRR-AMSR, shows a similar abrupt enhancement of mesoscale SST variability in June 2002, when the AMSR-E instrument was incorporated. This issue leaves potential influences on scientific research that utilize the OISST datasets. The composite SST anomalies of mesoscale eddies based on the OI.v2-AVHRR-only data are underestimated by up to 37% before 2007 in the subtropical WBC regions. The underestimation of mesoscale variability also affects the total (full-scale) SST variability, particularly in winter. Other SST data products based on the OISST datasets were also influenced; we identify suspicious changes in J-OFURO3 and CFSR datasets; the reconstructed three-dimensional ocean products using OISST data as input may also be inevitably affected. This study reminds caution in the usage of the OISST and relevant data products in the investigation of mesoscale processes.

Background Endothelial cell injury, induced by dyslipidemia, is the initiation of atherosclerosis, resulting in an imbalance in endothelial fatty acid (FA) transport. Pigment epithelial‐derived factor (PEDF) is an important regulator in lipid metabolism. We hypothesized that PEDF is involved in endothelium‐mediated FA uptake under hyperlipidemic conditions. Methods and Results Circulating PEDF levels were higher in patients with atherosclerotic cardiovascular disease than in normal individuals. However, decreasing trends of serum PEDF levels were confirmed in both wild‐type and apolipoprotein E–deficient mice fed a long‐term high‐fat diet. Apolipoprotein E–deficient/PEDF‐deficient mice were generated by crossing PEDF‐deficient mice with apolipoprotein E–deficient mice, and then mice were fed with 24, 36, or 48 weeks of high‐fat diet. Greater increases in body fat and plasma lipids were displayed in PEDF‐deficient mice. In addition, PEDF deficiency in mice accelerated atherosclerosis, as evidenced by increased atherosclerotic plaques, pronounced vascular dysfunction, and increased lipid accumulation in peripheral tissues, whereas injection of adeno‐associated virus encoding PEDF exerted opposite effects. Mechanistically, PEDF inhibited the vascular endothelial growth factor B paracrine signaling by reducing secretion of protein vascular endothelial growth factor B in peripheral tissue cells and decreasing expression of its downstream targets in endothelial cells, including its receptors (namely, vascular endothelial growth factor receptor‐1 and neuropilin‐1), and FA transport proteins 3 and 4, to suppress endothelial FA uptake, whereas PEDF deletion in mice activated the vascular endothelial growth factor B signaling pathway, thus causing markedly increased lipid accumulation. Conclusions Decreasing expression of PEDF aggravates atherosclerosis by significantly impaired vascular function and enhanced endothelial FA uptake, thus exacerbating ectopic lipid deposition in peripheral tissues.

This paper considers the problem of stabilizing switched time-delay linear systems through a state-dependent switching strategy. In contrast to the existing works, we adopt a less restrictive assumption of the system, and show that this assumption is sufficient to guarantee asymptotic stability of the considered system under the min-projection switching strategy. Our results also imply that the min-projection switching strategy, originally designed for delay-free switched systems, is robust with respect to small state delays. An optimization problem is formulated to estimate the upper bound of the tolerable time delay. Numerical examples are presented to show that our method is applicable to a larger class of switched systems and leads to a greater delay bound.

This paper studied the impact of moisture on the correlated characteristics of the condenser bushings oil-paper insulation system. The oil-impregnated paper samples underwent accelerated thermal aging at 130 °C after preparation at different initial moisture contents (1%, 3%, 5% and 7%). All the samples were extracted periodically for the measurement of the moisture content, the degree of polymerization (DP) and frequency domain dielectric spectroscopy (FDS). Next, the measurement results of samples were compared to the related research results of transformer oil-paper insulation, offering a theoretical basis of the parameter analysis. The obtained results show that the moisture fluctuation amplitude can reflect the different initial moisture contents of insulating paper and the mass ratio of oil and paper has little impact on the moisture content fluctuation pattern in oil-paper but has a great impact on moisture fluctuation amplitude; reduction of DP presents an accelerating trend with the increase of initial moisture content, and the aging rate of test samples is higher under low moisture content but lower under high moisture content compared to the insulation paper in transformers. Two obvious “deceleration zones” appeared in the dielectric spectrum with the decrease of frequency, and not only does the integral value of dielectric dissipation factor (tan δ) reflect the aging degree, but it reflects the moisture content in solid insulation. These types of research in this paper can be applied to evaluate the condition of humidified insulation and the aging state of solid insulation for condenser bushings.

Spinal cord injury (SCI) is a severe neurological trauma that involves complex pathological processes. Inflammatory response and oxidative stress are prevalent during the second injury and can influence the functional recovery of SCI. Specially, Apolipoprotein E (APOE) induces neuronal repair and nerve regeneration, and the deficiency of Apoe impairs spinal cord-blood-barrier and reduces functional recovery after SCI. However, the mechanism by which Apoe mediates signaling pathways of inflammatory response and oxidative stress in SCI remains largely elusive. This study was designed to investigate the signaling pathways that regulate Apoe deficiency-dependent inflammatory response and oxidative stress in the acute stage of SCI. In the present study, Apoe−/− mice retarded functional recovery and had a larger lesion size when compared to wild-type mice after SCI. Moreover, deficiency of Apoe induced an exaggerated inflammatory response by increasing expression of interleukin-6 (IL-6) and interleukin-1β (IL-1β), and increased oxidative stress by reducing expression of Nrf2 and HO-1. Furthermore, lack of Apoe promoted neuronal apoptosis and decreased neuronal numbers in the anterior horn of the spinal cord after SCI. Mechanistically, we found that the absence of Apoe increased inflammation and oxidative stress through activation of NF-κB after SCI. In contrast, an inhibitor of nuclear factor-κB (NF-κB; Pyrrolidine dithiocarbamate) alleviates these changes. Collectively, these results indicate that a critical role for activation of NF-κB in regulating Apoe-deficiency dependent inflammation and oxidative stress is detrimental to recovery after SCI.

Efficient molecular markers for the selection of rapeseed genetic materials with high seed oil content and ideal fatty acid (FA) composition are preferred by rapeseed breeders. Recently, we reported the molecular mechanism of TRANSPARENT TESTA 2 (TT2) in inhibiting seed FA biosynthesis in Arabidopsis. However, evidence showing the association of rapeseed TT2 homologs and seed FA production are still insufficient. In this study, we collected 83 rapeseed (Brassica napus L.) landraces from different geographical backgrounds to conduct association mapping of BnaC.TT2.a in relation to seed coat color and FA biosynthesis. Population background was corrected by 84 pairs of SSR markers that were uniformly distributed among the linkage groups of the Tapidor-Ningyou-7 DH population. A single copy of BnaC.TT2.a for single nucleotide polymorphism (SNP) assay was cloned by a pair of previously reported specific primers. From the analysis of BnaC.TT2.a allelic variations using GLM+Q model, four SNPs on intron 1 of BnaC.TT2.a that were associated with seed FA were discovered. Moreover, an InDel at position 738 on exon 3 of BnaC.TT2.a indicated a change of protein function that was significantly associated with seed coat color, linoleic acid (C18:2), and total FA content. These findings revealed the role of BnaC.TT2.a in regulating the seed color formation and seed FA biosynthesis in rapeseed, thereby suggesting effective molecular markers for rapeseed breeding.