The Performance of Downward Shortwave Radiation Products from Satellite and Reanalysis over the Transect of Zhongshan Station to Dome A, East Antarctica

The downward shortwave radiation(DSR) is an important part of the Earth's energy balance, driving Earth's system's energy, water, and carbon cycles. Due to the harsh Antarctic environment, the accuracy of DSR derived from satellite and reanalysis has not been systematically evaluated over the transect of Zhongshan station to Dome A, East Antarctica.Therefore, this study aims to evaluate DSR reanalysis products(ERA5-Land, ERA5, MERRA-2) and satellite products(CERES and ICDR) in this area. The results indicate that DSR exhibits obvious monthly and seasonal variations, with higher values in summer than in winter. The ERA5-Land(ICDR) DSR product demonstrated the highest(lowest) accuracy,as evidenced by a correlation coefficient of 0.988(0.918), a root-mean-square error of 23.919(69.383) W m^(–2), a mean bias of –1.667(–28.223) W m^(–2) and a mean absolute error of 13.37(58.99) W m^(–2). The RMSE values for the ERA5-Land reanalysis product at seven stations, namely Zhongshan, Panda 100, Panda 300, Panda 400, Taishan, Panda 1100, and Kunlun, were 30.938, 29.447, 34.507, 29.110, 20.339, 17.267, and 14.700 W m^(-2), respectively;with corresponding bias values of 9.887, –12.159, –19.181, –15.519, –8.118, 6.297, and 3.482 W m^(–2). Regarding seasonality, ERA5-Land, ERA5,and MERRA-2 reanalysis products demonstrate higher accuracies during spring and summer, while ICDR products are least accurate in autumn. Cloud cover, water vapor, total ozone, and severe weather are the main factors affecting DSR. The error of DSR products is greatest in coastal areas(particularly at the Zhongshan station) and decreases towards the inland areas of Antarctica.

High piezo/photocatalytic efficiency of Ag/Bi_(5)O_(7)I nanocomposite using mechanical and solar energy for N2 fixation and methyl orange degradation

In this work,Ag/Bi_(5)O_(7)I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange(MO)degradation.Bi_(5)O_(7)I was synthesized via a hydrothermal-calcination method and shows nanorods morphology.Ag nanoparticles(NPs)were photo deposited on the Bi_(5)O_(7)I nanorods as electron trappers to improve the spatial separation of charge carriers,which was confirmed via XPS,TEM,and electronic chemical analyses.The catalytic test indicates that Bi_(5)O_(7)I presents the piezoelectric-like behavior,while the loading of Ag NPs can strengthen the character.Under ultrasonic vibration,the optimal Ag/Bi_(5)O_(7)I presents high efficiency in MO degradation.The degradation rate is determined to be 0.033 min
1,which is 4.7 folds faster than that of Bi_(5)O_(7)I.The Ag/Bi_(5)O_(7)I also presents a high performance in piezocatalytic N2 fixation.The piezocatalytic NH3 generation rate reaches 65.4 μmol L^(-1)g^(-1)h^(-1)with water as a hole scavenger.The addition of methanol can hasten the piezoelectric catalytic reaction.Interestingly,when ultrasonic vibration and light irradiation simultaneously act on the Ag/Bi_(5)O_(7)I catalyst,higher performance in NH3 generation and MO degradation is observed.However,due to the weak adhesion of Ag NPs,some Ag NPs would fall off from the Bi_(5)O_(7)I surface under long-term ultrasonic vibration,which would greatly reduce the piezoelectric catalytic performance.This result indicates that a strong binding force is required when preparing the piezoelectric composite catalyst.The current work provides new insights for the development of highly efficient catalysts that can use multiple energies.

Learning-Based Joint Service Caching and Load Balancing for MEC Blockchain Networks

Integrating the blockchain technology into mobile-edge computing(MEC)networks with multiple cooperative MEC servers(MECS)providing a promising solution to improving resource utilization,and helping establish a secure reward mechanism that can facilitate load balancing among MECS.In addition,intelligent management of service caching and load balancing can improve the network utility in MEC blockchain networks with multiple types of workloads.In this paper,we investigate a learningbased joint service caching and load balancing policy for optimizing the communication and computation resources allocation,so as to improve the resource utilization of MEC blockchain networks.We formulate the problem as a challenging long-term network revenue maximization Markov decision process(MDP)problem.To address the highly dynamic and high dimension of system states,we design a joint service caching and load balancing algorithm based on the double-dueling Deep Q network(DQN)approach.The simulation results validate the feasibility and superior performance of our proposed algorithm over several baseline schemes.

Microbiome Engineering:A Promising Approach to Improve Coral Health

The world’s coral reefs are threatened by the cumulative impacts of global climate change and local stressors.Driven largely by a desire to understand the interactions between corals and their symbiotic microorganisms,and to use this knowledge to eventually improve coral health,interest in coral microbiology and the coral microbiome has increased in recent years.In this review,we summarize the role of the coral microbiome in maintaining a healthy metaorganism by providing nutrients,support for growth and development,protection against pathogens,and mitigation of environmental stressors.We explore the concept of coral microbiome engineering,that is,precise and controlled manipulation of the coral microbiome to aid and enhance coral resilience and tolerance in the changing oceans.Although coral microbiome engineering is clearly in its infancy,several recent breakthroughs indicate that such engineering is an effective tool for restoration and preservation of these valuable ecosystems.To assist with identifying future research targets,we have reviewed the common principles of microbiome engineering and its applications in improving human health and agricultural productivity,drawing parallels to where coral microbiome engineering can advance in the not-too-distant future.Finally,we end by discussing the challenges faced by researchers and practitioners in the application of microbiome engineering in coral reefs and provide recommendations for future work.

Research on Distributed Cooperative Control Strategy of Microgrid Hybrid Energy Storage Based on Adaptive Event Triggering

Distributed collaborative control strategies for microgrids often use periodic time to trigger communication,which is likely to enhance the burden of communication and increase the frequency of controller updates,leading to greater waste of communication resources.In response to this problem,a distributed cooperative control strategy triggered by an adaptive event is proposed.By introducing an adaptive event triggering mechanism in the distributed controller,the triggering parameters are dynamically adjusted so that the distributed controller can communicate only at a certain time,the communication pressure is reduced,and the DC bus voltage deviation is effectively reduced,at the same time,the accuracy of power distribution is improved.The MATLAB/Simulink modeling and simulation results prove the correctness and effectiveness of the proposed control strategy.

Morphology and Function of the Aortic Valve after Transcatheter Closure of Ventricular Septal Defect with Aortic Valve Prolapse

Objective:This study aims to evaluate the morphology and function of the aortic valve after transcatheter closure of ventricular septal defect(VSD)with aortic valve prolapse(AVP)abased on clinical and radiological outcomes.Methods:From January 2013 to November 2014,164 consecutive patients(97 males,59.1%)with VSD and AVP were treated by transcatheter closure.The patients were divided into the mild AVP group(n=63),moderate AVP group(n=89)and severe AVP group(n=12).The clinical and radiological outcomes of these patients were analyzed retrospectively.Results:In total,146(89.0%)patients were successfully treated with VSD occluders,including 59/63(93.7%)with mild AVP,80/89(89.9%)with moderate AVP and 7/12(58.3%)with severe AVP.The degree of AVP was ameliorated or disappeared in 39(26.7%)patients,and remained unchanged in 103(70.5%)patients after the intervention.In the 35 patients who initially had trivial-to-moderate aortic regurgitation(AR),the degree of AR was ameliorated or disappeared in 25(71.4%)patients,aggravated from trivial to mild AR in 1(2.9%)patient,and remained unchanged in 9(25.7%)patients.In 111 patients without AR,1(0.9%)patient had mild AR and 24(21.6%)patients had trivial AR after intervention.The depth and width of the prolapsed aortic valve decreased after transcatheter closure of VSD in all three groups.During the 70-month(range,54–77)follow-up period,no patients with AVP and AR needed an aortic valve intervention.Conclusions:Transcatheter closure of VSD with AVP is feasible.The morphology and function of the prolapsed aortic valve improved and remained stable for a long period after intervention.

Regulation of metabolic microenvironment with a nanocomposite hydrogel for improved bone fracture healing

Bone nonunion poses an urgent clinical challenge that needs to be addressed.Recent studies have revealed that the metabolic microenvironment plays a vital role in fracture healing.Macrophages and bone marrow-derived mesenchymal stromal cells(BMSCs)are important targets for therapeutic interventions in bone fractures.Itaconate is a TCA cycle metabolite that has emerged as a potent macrophage immunomodulator that limits the inflammatory response.During osteogenic differentiation,BMSCs tend to undergo aerobic glycolysis and metabolize glucose to lactate.Copper ion(Cu^(2+))is an essential trace element that participates in glucose metabolism and may stimulate glycolysis in BMSCs and promote osteogenesis.In this study,we develop a 4-octyl itaconate(4-OI)@Cu@Gel nanocomposite hydrogel that can effectively deliver and release 4-OI and Cu^(2+)to modulate the metabolic microenvironment and improve the functions of cells involved in the fracture healing process.The findings reveal that burst release of 4-OI reduces the inflammatory response,promotes M2 macrophage polarization,and alleviates oxidative stress,while sustained release of Cu^(2+)stimulates BMSC glycolysis and osteogenic differentiation and enhances endothelial cell angiogenesis.Consequently,the 4-OI@Cu@Gel system achieves rapid fracture healing in mice.Thus,this study proposes a promising regenerative strategy to expedite bone fracture healing through metabolic reprogramming of macrophages and BMSCs.

Barriers to the Acceptance of Tuberculosis Preventive Treatment:A Multicenter Cross-sectional Study in China

Objective We aimed to understand the willingness and barriers to the acceptance of tuberculosis(TB)preventive treatment(TPT)among people with latent TB infection(LTBI)in China.Methods A multicenter cross-sectional study was conducted from May 18,2023 to December 31,2023 across 10 counties in China.According to a national technical guide,we included healthcare workers,students,teachers,and others occupations aged 15-65 years as our research participants.Results Overall,17.0%(183/1,077)of participants accepted TPT.There were statistically significant differences in the acceptance rate of TPT among different sexes,ages,educational levels,and occupations(P<0.05).The main barriers to TPT acceptance were misconceptions that it had uncertain effects on prevention(57.8%,517/894),and concerns about side effects(32.7%,292/894).Conclusion An enhanced and comprehensive understanding of LTBI and TPT among people with LTBI is vital to further expand TPT in China.Moreover,targeted policies need to be developed to address barriers faced by different groups of people.

Sources of ambient non-methane hydrocarbon compounds and their impacts on O_(3) formation during autumn,Beijing

The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±11.39 ppbv during this period,and alkanes were the major components.There were typical festival effects of NMHCs with lower concentration during the National Day.Alkenes and aromatics were the dominant groups in ozone formation potential(OFP)and OH radical loss rate(L_(OH)).The positive matrix factorization(PMF)running results revealed that vehicular exhaust became the biggest source in urban areas,followed by liquefied petroleum gas(LPG)usage,solvent usage,and fuel evaporation.The box model coupled with master chemical mechanism(MCM)was applied to study the impacts of different NMHCs sources on ozone(O_(3))formation in an O_(3)episode.The simulation results indicated that reducing NMHCs concentration could effectively suppress O_(3)formation.Moreover,reducing traffic-related emissions of NMHCs was an effective way to control O_(3)pollution at an urban site in Beijing.

Atmospheric oxidizing capacity in autumn Beijing:Analysis of the O_(3) and PM_(2.5) episodes based on observation-based model

Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AOC still remains uncertainty.In this study,a comprehensive field campaign was conducted during autumn 2019 in downtown of Beijing,where O_(3) and PM_(2.5) episodes had been experienced successively.The observation-based model(OBM)is used to quantify the AOC at O_(3) and PM_(2.5) episodes.The strong intensity of AOC is found at O_(3) and PM2.5 episodes,and hydroxyl radical(OH)is the dominating daytime oxidant for both episodes.The photolysis of O_(3) is main source of OH at O_(3) episode;the photolysis of nitrous acid(HONO)and formaldehyde(HCHO)plays important role in OH formation at PM_(2.5) episode.The radicals loss routines vary according to precursor pollutants,resulting in different types of air pollution.O_(3) budgets and sensitivity analysis indicates that O_(3) production is transition regime(both VOC and NOx-limited)at O3 episode.The heterogeneous reaction of hydroperoxy radicals(HO_(2))on aerosol surfaces has significant influence on OH and O_(3) production rates.The HO_(2) uptake coefficient(γHO_(2))is the determining factor and required accurate measurement in real atmospheric environment.Our findings could provide the important bases for coordinated control of PM_(2.5) and O_(3) pollution.

Sin1/mTORC2 regulate B cell growth and metabolism by activating mTORC1 and Myc

Proper control of B cell growth and metabolism is crucial for B-cell-mediated immunity,but the underlying molecular mechanisms remain incompletely understood.In this study,Sin1,a key component of mTOR complex 2(mTORC2),specifically regulates B cell growth and metabolism.Genetic ablation of Sin1 in B cells reduces the cell size at either the transitional stage or upon antigen stimulation and severely impairs metabolism.Sin1 deficiency also severely impairs B-cell proliferation,antibody responses,and anti-viral immunity.At the molecular level,Sin1 controls the expression and stability of the c-Myc protein and maintains the activity of mTORC1 through the Akt-dependent inactivation of GSK3 and TSC1/2,respectively.Therefore,our study reveals a novel and specific role for Sin1 in coordinating the activation of mTORC2 and mTORC1 to control B cell growth and metabolism.

Urine-derived stem cells:applications in skin,bone and articular cartilage repair

As an emerging type of adult stem cell featuring non-invasive acquisition,urine-derived stem cells(USCs)have shown great potential for applications in tissue engineering and regenerative medicine.With a growing amount of research on the topic,the effectiveness of USCs in various disease models has been shown and the underlying mechanisms have also been explored,though many aspects still remain unclear.In this review,we aim to provide an up-to-date overview of the biological characteristics of USCs and their applications in skin,bone and articular cartilage repair.In addition to the identification procedure of USCs,we also summarize current knowledge of the underlying repair mechanisms and application modes of USCs.Potential concerns and perspectives have also been summarized.

南极爆发性增温创造新纪录

Antarctica is considered as an important component of the global climate system, not only because of its ability to drive global sea-level rise through ice melting [1], but also because of its stabilizing effect on global atmospheric energy balance/circulation [2].In recent years, Antarctica has experienced rapid climatic changes and frequent climate extremes, such as a rapid decrease in summer sea ice extent since 2016 [3] and the highest air temperature recorded at Esperanza station in the Antarctic Peninsula on 9February 2020 [4]. In this context, climate extremes in Antarctica have received increasing attention recently [4–7].

Anti-clogging ability of the labyrinth emitter and its evaluation method

Emitter clogging is one of the most serious factors that restrict the drip irrigation system operation and water use efficiency.To scientifically characterize and evaluate emitter clogging risk,a literature review,short-period emitter anti-clogging tests,and CFD(Computational Fluid Dynamics)hydraulic performance tests were conducted.Results showed that the emitter anti-clogging ability is related to its structure,material,and processing technology,not external factors.This was evidenced in the irrigation tests,as with the different water qualities,the same emitters were repeatedly prone to clog or to avoid clogging.A predictive model of structural resistance coefficient(Cs),a quantitative indicator of the emitter anti-clogging ability,whose value ranges between 0 and 1,was utilized.Larger Cs values indicate a lower anti-clogging ability and thus a higher risk of clogging.A good linear relationship between Cs and the relative flow rate was detected,and the Cs relationship with the fluidity index(x)was determined to be a power function.The Cs should be controlled within the range of 0.146-0.461 when designing new emitters to ensure that they have good anti-clogging properties.This research will provide theoretical guidance for the anti-clogging management of drip irrigation systems and for the design of optimal emitter structures.

Two-dimensional mesoporous sensing materials

Two-dimensional mesoporous materials combing ultrathin nanosheet morphology with well-defined mesoporous structures,are now emerging and becoming increasingly important for their promising applications in energy storage,electronic devices,electrocatalysts and so on.Here,we synthesized a kind of polypyrrole-based two-dimensional mesoporous materials with uniform pore size,ultrathin thickness and high surface area.Serving for electrochemical NH3 sensor,they exhibited a fast response and high sensitivity.Therefore,our study would promote much interest in design of new materials for gas sensor applications.

Glucose-responsive,antioxidative HA-PBA-FA/EN106 hydrogel enhanced diabetic wound healing through modulation of FEM1b-FNIP1 axis and promoting angiogenesis

The diabetic wounds remain to be unsettled clinically,with chronic wounds characterized by drug-resistant bacterial infections,compromised angiogenesis and oxidative damage to the microenvironment.To ameliorate oxidative stress and applying antioxidant treatment in the wound site,we explore the function of folliculininteracting protein 1(FNIP1),a mitochondrial gatekeeper protein works to alter mitochondrial morphology,reduce oxidative phosphorylation and protect cells from unwarranted ROS accumulation.And our in vitro experiments showed the effects of FNIP1 in ameliorating oxidative stress and rescued impaired angiogenesis of HUVECs in high glucose environment.To realize the drug delivery and local regulation of FNIP1 in diabetic wound sites,a novel designed glucose-responsive HA-PBA-FA/EN106 hydrogel is introduced for improving diabetic wound healing.Due to the dynamic phenylboronate ester structure with a phenylboronic acid group between hyaluronic acid(HA)and phenylboronic acid(PBA),the hydrogel is able to realize a glucose-responsive release of drugs.Fulvic acid(FA)is added in the hydrogel,which not only severs as crosslinking agent but also provides antibacterial and anti-inflammatory abilities.Moreover,the release of FEM1b-FNIP1 axis inhibitor EN106 ameliorated oxidative stress and stimulated angiogenesis through FEM1b-FNIP1 axis regulation.These in vivo and in vitro results demonstrated that accelerated diabetic wounds repair with the use of the HA-PBA-FA/EN106 hydrogel,which may provide a promising strategy for chronic diabetic wound repair.

Formation mechanisms of nitrous acid(HONO) during the haze and non-haze periods in Beijing,China

As an important precursor of hydroxyl radical(OH),nitrous acid(HONO)plays a significant role in atmospheric chemistry.Here,an observation of HONO and relevant air pollutants in an urban site of Beijing from 14 to 28 April,2017 was performed.Two distinct peaks of HONO concentrations occurred during the observation.In contrast,the concentration of particulate matter in the first period(periodⅠ)was significantly higher than that in the second period(periodⅡ).Comparing to HONO sources in the two periods,we found that the direct vehicle emissionwas an essential source of the ambient HONO during both periods at night,especially in periodⅡ.The heterogeneous reaction of NO_(2)was the dominant source in periodⅠ,while the homogeneous reaction of NO with OH was more critical source at night in periodⅡ.In the daytime,the heterogeneous reaction of NO_(2)was a significant source andwas confirmed by the good correlation coefficients(R^(2))between the unknown sources(P_(unknown))with NO_(2),PM_(2.5),NO_(2)×PM_(2.5)in periodⅠ.Moreover,when solar radiation and OH radicals were considered to explore unknown sources in the daytime,the enhanced correlation of P_(unknown)with photolysis rate of NO_(2)and OH(J_(NO_(2))×OH)were 0.93 in periodⅠ,0.95 in periodⅡ.These excellent correlation coefficients suggested that the unknown sources released HONO highly related to the solar radiation and the variation of OH radicals.

中国首个格陵兰冰盖自动气象站

The Greenland ice sheet(GrIS)is the second largest ice sheet in the world,but it is the largest contributor to sea level rise[1]as global warming continues.If its mass was lost completely,global mean sea level would rise by about 7.2 m[2].Over the recent three decades,mass loss of the GrIS driven by oceanic and atmospheric warming has been significantly increased[3].