New Record Ocean Temperatures and Related Climate Indicators in 2023

The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m ocean heat content(OHC)reached record highs.The 0–2000 m OHC in 2023 exceeded that of 2022 by 15±10 ZJ(1 Zetta Joules=1021 Joules)(updated IAP/CAS data);9±5 ZJ(NCEI/NOAA data).The Tropical Atlantic Ocean,the Mediterranean Sea,and southern oceans recorded their highest OHC observed since the 1950s.Associated with the onset of a strong El Niño,the global SST reached its record high in 2023 with an annual mean of~0.23℃ higher than 2022 and an astounding>0.3℃ above 2022 values for the second half of 2023.The density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023.

Intraseasonal variability of the surface zonal current in the equatorial Indian Ocean:Seasonal differences and causes

Using observations and numerical simulations,this study examines the intraseasonal variability of the surface zonal current(u ISV)over the equatorial Indian Ocean,highlighting the seasonal and spatial differences,and the causes of the differences.Large-amplitude u ISV occurs in the eastern basin at around 80°–90°E and near the western boundary at 45°–55°E.In the eastern basin,the u ISV is mainly caused by the atmospheric intraseasonal oscillations(ISOs),which explains 91%of the standard deviation of the total u ISV.Further analysis suggests that it takes less than ten days for the intraseasonal zonal wind stress to generate the u ISV through the directly forced Kelvin and Rossby waves.Driven by the stronger zonal wind stress associated with the Indian summer monsoon ISO(MISO),the eastern u ISV in boreal summer(May to October)is about 1.5 times larger than that in boreal winter(November to April).In the western basin,both the atmospheric ISOs and the oceanic internal instabilities contribute substantially to the u ISV,and induce stronger u ISV in boreal summer.Energy budget analysis suggests that the mean flow converts energy to the intraseasonal current mainly through barotropic instabilities.

Another Year of Record Heat for the Oceans

Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum.According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ(1 Zetta Joules = 1021Joules);and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins(the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier–fresh gets fresher” pattern, also reached its highest level on record in 2022,implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Ni?a event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.

Global practical stabilization of the double integrator system with an imperfect sensor and subject to a bounded disturbance

This paper is concerned with global practical stabilization of the double integrator system with an imperfect sensor and subject to an additive bounded output disturbance.The imperfect sensor nonlinearity possesses the nonlinear characteristics of saturation and dead zone.Because of the presence of output dead zone and the additive disturbance,the states cannot be expected to driven into an arbitrarily small neighborhood of the origin.To solve the global practical stabilization problem,we proposes a low gain-based linear dynamic output feedback law,under which the first state enters and remains in a bounded set whose size is depended on the bound of disturbance and the range of dead zone and the second state enters and remains in a pre-specified arbitrarily small set,both in finite time.Simulation results illustrate the effectiveness of our proposed control method.

Another Record: Ocean Warming Continues through 2021 despite La Nina Conditions

The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ(1 zetta J = 1021 J) using the IAP/CAS dataset and by16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Nino-Southern Oscillation(ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans,and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.

SUMOylation-triggered ALIX activation modulates extracellular vesicles circTLCD4-RWDD3 to promote lymphatic metastasis of non-small cell lung cancer

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.

现阶段磨矿介质的研究进展及发展方向

我国矿产资源丰富,但富矿资源比较少,要通过磨矿作业来将有用矿物和脉石矿物充分解离并达到合适的选别粒度。开展对矿介质的现状及发展趋势研究,提高磨矿作业中磨矿介质与矿物原料的匹配性,提高磨矿介质的针对性,对实现对资源的综合、高效利用,是很有必要的。

Semi-global weighted output average tracking of discrete-time heterogeneous multi-agent systems subject to input saturation and external disturbances

In this paper,we revisit the semi-global weighted output average tracking problem for a discrete-time multi-agent system subject to input saturation and external disturbances.The multi-agent system consists of multiple heterogeneous linear systems as leader agents and multiple heterogeneous linear systems as follower agents.We design both the state feedback and output feedback control protocols for each follower agent.In particular,a distributed state observer is designed for each follower agent that estimates the state of each leader agent.In the output feedback case,state observer is also designed for each follower agent to estimate its own state.With these estimates,we design low gain-based distributed control protocols,parameterized in a scalar low gain parameter.It is shown that,for any bounded set of the initial conditions,these control protocols cause the follower agents to track the weighted average of the outputs of the leader agents as long as the value of the low gain parameter is tuned sufficiently small.Simulation results illustrate the validity of the theoretical results.

小于胎龄儿脐血非蛋白结合铁和氧化应激状况的研究

目的探讨小于胎龄儿(small for gestational age,SGA)脐血非蛋白结合铁(non-protein-bound iron,NPBI)水平及氧化应激状况。方法选择2021年3~12月中南大学湘雅医学院附属海口医院产科分娩、并参加前期课题留取脐动脉血的晚期早产儿和足月儿进行回顾性研究。将SGA纳入SGA组,从所有适于胎龄儿(appropriate for gestational age,AGA)中,按与SGA组1∶1的比例选择AGA纳入AGA组。比较两组脐血NPBI、8-异前列腺素F2α(8-isoprostagladin F2α,8-iso-PGF2α)、丙二醛(malondialdehyde,MDA)水平,分析NPBI与其他指标之间的关系。结果SGA组与AGA组分别纳入34例新生儿,SGA组脐血NPBI、8-iso-PGF2α和MDA水平均高于AGA组[3.9(2.6,5.1)nmol/ml比0.8(0.2,1.4)nmol/ml,(119.6±30.2)pg/ml比(66.5±22.7)pg/ml,4.6(4.1,5.1)nmol/ml比3.4(2.9,3.8)nmol/ml],差异有统计学意义(P<0.05)。SGA组脐血NPBI与8-iso-PGF2α和MDA水平均呈正相关(r=0.582,P=0.001;r=0.371,P=0.031);AGA组脐血NPBI与MDA水平呈正相关(r=0.492,P=0.003),与8-iso-PGF2α水平无相关(r=0.032,P=0.859)。结论SGA体内存在氧化应激,NPBI可能通过介导脂质过氧化引起SGA氧化应激的发生。

Coexistence of large positive and negative magnetoresistance in Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor

Magnetoresistance(MR)phenomenon couples the electron transport with magnetic field,which has been at the forefront of condensed matter physics and materials science.Large-MR behaviors are of particularly importance for magnetic sensor and information memory applications,and their scarcity has aroused intensive research.Moreover,due to the different physical origins,combination of large positive and negative MR(pMR and nMR)in one single compound has rarely been reported.In present work,we achieved a coexistence of large pMR and nMR in Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor single crystal with different field configurations.Specifically,a large nMR of about -60% was obtained under the in-plane field,while a large pMR higher than 1000% took over in the out-of-plane direction.We attribute this field direction-sensitive dualistic large MR behavior to the competition and cooperation effect from the ferromagnetic interaction,orbital scattering and electronic correlation that coexist in Cr_(2)Si_(2)Te_(6),which contribute to n MR,pMR,and nMR,respectively,in dominated temperature and field ranges,and show different weights under different field directions.The elucidated multiple MR mechanism in this ferromagnetic semiconductor will shed light on the pursuit of coexistence of large p MR and nMR for field-sensitive device applications.