This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source...This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline.展开更多
The hot deformation behavior of the premium GH4738 alloy was investigated in the temperature range of 1313 to 1353 K at strain rates of 0.01 to 1 s^(−1)using the hot compression test.To accurately predict flow stress,...The hot deformation behavior of the premium GH4738 alloy was investigated in the temperature range of 1313 to 1353 K at strain rates of 0.01 to 1 s^(−1)using the hot compression test.To accurately predict flow stress,three novel strain compensation constitutive equations were developed and rigorously assessed.The results indicate that the power function model(correlation coefficients r=0.98544)demonstrates greater prediction accuracy compared to other functions,with a calculated average activation energy of 507.968 kJ mol−1.Additionally,electron backscattered diffraction technology and transmission electron microscopy were used to analyze the evolution of the alloy microstructure during dynamic recrystallization under different deformation conditions.The results show that under high-temperature and large deformation conditions,the dislocation density and the degree of grain rotation increase,which promotes the formation and growth of new recrystallized grains,so that recrystallization is completed when the deformation amount reaches 30%.Besides,the increase in the temperature not only enhances the thermal activation mechanism,but also improves the grain size uniformity and texture consistency.Meanwhile,the carbide inhibits grain overgrowth by pinning grain boundaries,maintaining a fine and uniform grain structure of the alloy,and thereby improving the plasticity of the material.展开更多
BACKGROUND Krüppel-like factor-5(KLF5)is a zinc-finger transcription factor related to tumor progression.However,the relationship between KLF5 and lung cancer remains to be identified.AIM To investigate the clini...BACKGROUND Krüppel-like factor-5(KLF5)is a zinc-finger transcription factor related to tumor progression.However,the relationship between KLF5 and lung cancer remains to be identified.AIM To investigate the clinical value of KLF5 and interference with KLF5 mRNA transcription on the effects of biological behaviors in lung squamous-cell carcinoma(LUSC).METHODS Lung KLF5 mRNA data were extracted from bioinformatics databases.Blood and tissues from a cohort of patients with benign or malignant lung diseases were collected with ethical committee consent to validate KLF5 expression via multiplex immunofluorescence and immunohistochemistry,Western blot,Enzyme Linked Immunosorbent Assay or quantitative polymerase chain reaction.Furthermore,KLF5 mRNA was silenced in lung A549 cells to validate biological behaviors in vitro and nude mouse xenograft growth in vivo,respectively.RESULTS A cohort of bioinformatics databases revealed high KLF5 mRNA expression in LUSC(P<0.001)but lower KLF5 mRNA expression in lung adenocarcinoma.Upregulated KLF5 in the lung or sera of patients with lung cancer(P<0.001)were confirmed that related to poor differentiation,lymph node or distant metastasis.Furthermore,the incidence of KLF5 levels greater than 500 ng/mL in LUSC patients was 86.7%,which was significantly greater(P<0.001)than that in cases with benign lung diseases(13.3%)or healthy controls.Functionally,silencing KLF5 mRNA with a specific shRNA significantly suppressed A549 cell proliferation,decreased cell migration,increased the ratio of G2 phase cells in vitro,and inhibited the growth of nude mouse xenografts in vivo.CONCLUSION KLF5 is a novel diagnostic biomarker or potential therapeutic target for LUSC.展开更多
Polynyas and their adjacent seasonal ice zones(SIZs)represent the most productive regions in the Southern Ocean,supporting unique food webs that are highly sensitive to climate change.Understanding the dynamics of phy...Polynyas and their adjacent seasonal ice zones(SIZs)represent the most productive regions in the Southern Ocean,supporting unique food webs that are highly sensitive to climate change.Understanding the dynamics of phytoplankton and the carbon pool in these areas is crucial for assessing the role of the Southern Ocean in global carbon cycling.During the late stage of an algal bloom,seawater samples at 14 stations were collected in the Amundsen Sea Polynya(ASP)and adjacent SIZ.Using nutrients,phytoplankton pigments,organic carbon(OC),remote sensing data,and physicochemical measurements,as well as CHEMTAX model simulations,we investigated the response of the phytoplankton crops,taxonomic composition,and OC pool to environmental factors.Our analyses revealed that hydrodynamic regimes of the polynya,adjacent SIZs and open sea were regulated by the regionally varying intrusion of Circumpolar Deep Water,photosynthetically active radiation and sea ice melt water.The ASP exhibited the highest seasonal nutrient utilization rates[ΔN=(1059±386)mmol/m^(2),ΔP=(50±17)mmol/m^(2) andΔSi=(956±904)mmol/m^(2)],while the open sea had lower rates.The integrated chlorophyll a(Chl a)concentration at depths of 0–200 m ranged from 20.4 mg/m^(2) to 1420.0 mg/m^(2) and peaked in the polynya.In the study area,Haptophytes Phaeocystis antarctica was the dominant functional group(34%±27%),and diatoms acted as a secondary contributor(23%±14%).The major functional group and particulate OC(POC)contributor varied from diatoms(36%±12%)in the open sea to haptophytes(48%±31%)in the polynya waters.Strong light conditions and microelement limitations promoted the dominance of P.antarctica(low Fe forms)dominance in the ASP.The strong correlations between the POC and Chl a depth-integrated concentration suggest that the POC was primarily derived from phytoplankton,while dissolved OC(DOC)was influenced by consumer activity and water mass transport.In addition,the transport of OC in the upper 200 m of the water column within the ASP was quantified,revealing the predominantly westward fluxes for both DOC[9.0 mg/(m^(2)·s)]and POC[7.2 mg/(m^(2)·s)].The latitudinal transport exhibited the northward transport of DOC[8.1 mg/(m^(2)·s)]and southward transport of POC[4.3 mg/(m^(2)·s)]movement.These findings have significant implications for enhancing our understanding of how hydrodynamics influence OC cycling in polynya regions.展开更多
BACKGROUND Whether rtS106C+H126Y+D134E/rtS106C+H126Y+D134E+L269I(rtCYE/rtCYEI)mutations in the hepatitis B virus(HBV)reverse-transcriptase(RT)region are associated with tenofovir disoproxil fumarate(TDF)resistance is ...BACKGROUND Whether rtS106C+H126Y+D134E/rtS106C+H126Y+D134E+L269I(rtCYE/rtCYEI)mutations in the hepatitis B virus(HBV)reverse-transcriptase(RT)region are associated with tenofovir disoproxil fumarate(TDF)resistance is controversial.AIM To evaluate the presence of the rtCYE/rtCYEI mutations in a large cohort of Chinese patients with chronic HBV infection.METHODS A total of 28236 patients who underwent drug resistance testing at the Fifth Medical Center of Chinese PLA General Hospital from 2007 to 2019 were enrolled.All patients received nucleoside/nucleotide analogues(NAs)therapy,and serum samples were collected for sequence analysis of the HBV RT domain with mutation analysis.RESULTS The detection rates of a single mutation of rtS106C,rtH126Y,rtD134E,and rtL269I were 8.21%,3.20%,2.55%and 61.49%in 23718 genotype C patients,and 1.31%,1.76%,0.21%,and 92.33%in 4266 genotype B patients,respectively.The combined mutations of rtCYE/rtCYEI were only detected in 12 genotype C patients,accounting for 0.042%of all patients.These 12 patients had received NA treatments except TDF before testing.Among them,6 patients had coexisting rtCYE/rtCYEI and lamivudine-resistance mutations,and 2 patients had coexisting rtCYE/rtCYEI and adefovir-resistance mutations.Compared with the wild-type(WT)strain,the replication capacity of rtCYE/rtCYEI mutants from representative patients decreased by 41.1%-71.8%,and TDF susceptibility reduced by less than 2-fold,but rtCYEI+rtA181V/N236T mutants exhibited a 6.2-/9.9-fold decrease in TDF susceptibility.Molecular modeling showed that rtCYE/rtCYEI mutants had a slight decrease in binding energy to TDF compared to the WT strain.In the clinic,emergence of the rtCYE/rtCYEI mutations was not specifically associated with TDF treatment.CONCLUSION HBV rtCYE/rtCYEI mutations have a limited effect on TDF susceptibility and are not sufficient to cause TDF resistance.展开更多
Objective:Neuroblastoma(NB)is frequently associated with high-risk pediatric cases that demonstrate limited response to cisplatin,contributing to a poor prognosis.Recent studies have explored the role of tumor cell se...Objective:Neuroblastoma(NB)is frequently associated with high-risk pediatric cases that demonstrate limited response to cisplatin,contributing to a poor prognosis.Recent studies have explored the role of tumor cell senescence in increasing sensitivity to this chemotherapy agent.This study aims to identify genes related to cell senescence in children diagnosed with NB,evaluate their influence on cisplatin sensitivity,and investigate potential strategies to enhance the efficacy of chemotherapy.Methods:Gene expression profiles and clinical data were obtained for 498 NB patients from the GEO database(GSE49710).The study focused on identifying genes that were differentially expressed between stage IV and other stages,particularly those linked to cell senescence and cisplatin resistance.To analyze the prognostic significance of these differentially expressed genes,we employed LASSO regression and multivariate Cox proportional hazards models.Transcriptomic and proteomic analyses of 15 NB specimens revealed a significant correlation between Flap endonuclease-1(FEN1)expression levels and both cellular senescence and sensitivity to cisplatin.We quantified FEN1 expression and cisplatin IC50 values in four different NB cell lines.The influence of FEN1 knockdown and overexpression on NB cell proliferation,invasion,and migration was evaluated using cloning assays,transwell assays,and scratch assays.Furthermore,we utilized Western blotting to analyze senescenceassociated proteins p21 and proliferating cell nuclear antigen(PCNA),thereby evaluating the role of FEN1 in cellular senescence.The impact of FEN1 on cisplatin sensitivity was investigated via the CCK-8 cell counting assay.Additionally,we investigated how FEN1 inhibitors might impact NB cell proliferation and enhance the therapeutic efficacy of cisplatin treatment.Results:FEN1 was found to be highly expressed in stage IV NB and showed a strong association with cisplatin sensitivity,establishing it as a critical molecular marker linked to poor patient prognosis.Notably,elevated FEN1 expression correlated with reduced sensitivity to cisplatin,as evidenced by higher IC50 values.In the SH-SY5Y cell line,FEN1 knockdown led to significant reductions in cell proliferation,invasion,and migration,along with an increase inβ-galactosidase staining—indicative of senescence.This knockdown also resulted in elevated levels of the p21 protein and decreased expression of PCNA,concurrently lowering cisplatin IC50 values.Conversely,FEN1 overexpression in the SK-N-SH cell line resulted in enhanced cell proliferation,invasion,and migration.This overexpression was associated with reducedβ-galactosidase staining,decreased levels of p21,and increased expression of PCNA,ultimately resulting in higher cisplatin IC50 values.Importantly,FEN1 inhibitors alone significantly impeded NB cell proliferation,and their combination with cisplatin further amplified this inhibitory effect compared to cisplatin treatment alone.Conclusions:Bioinformatics and sequencing analyses indicate that the senescence-related gene FEN1 is significantly associated with cisplatin sensitivity and adverse prognosis in pediatric NB.FEN1 plays a pivotal role in regulating NB cell proliferation,invasion,and migration,thereby facilitating cancer progression.Furthermore,it influences cisplatin sensitivity through its effects on cellular senescence.FEN1 inhibitors demonstrate potential both as monotherapies and in conjunction with cisplatin,suggesting that targeting FEN1 may be represent a valuable strategy for improving outcomes in high-risk NB patients.展开更多
In the traditional blast furnace(BF)ironmaking process in China,a notable deviation exists between the theoretical and actual yield of hot metal,leading to unexpected iron loss and restricting the improvement of produ...In the traditional blast furnace(BF)ironmaking process in China,a notable deviation exists between the theoretical and actual yield of hot metal,leading to unexpected iron loss and restricting the improvement of production capacity,which cannot adapt to the increasingly intensified smelting rhythm.Focusing on a BF in a Chinese steel enterprise,a deep neural network algorithm was designed to model the impact of multiple parameters on actual yield of hot metal in a single BF smelting cycle,successfully accomplishing the theoretical computation and real-time prediction of yield of hot metal for subsequent,unknown BF smelting cycle.Test results show that the proposed algorithm demonstrates an impressive prediction accuracy of 86.7% within an error range of±10 t and can swiftly complete the training and convergence process in 32.5 s.By integrating prediction results with Nomogram,a regulatory mechanism was engineered to minimize the deviation between theoretical and actual yield of hot metal.This mechanism ensures the yield enhancement of hot metal through dynamic adjustments of BF operational parameters.Industrial-scale application experiments confirmed that the intelligent operation and optimization system,developed in the laboratory,can maintain the yield deviation of hot metal within a stable range of 30 t,achieving a maximum reduction in iron loss rate of 17.65%compared to that before system operation.The findings provide robust support for the yield increase and efficiency improvement of the experimental BF.展开更多
IBI351,a synthetic compound,exerts its anti-tumor effects by specifically,covalently,and irreversibly modifying the 12th cysteine residue of KRAS G12C.However,the pharmacokinetic profile of IBI351 in humans has not ye...IBI351,a synthetic compound,exerts its anti-tumor effects by specifically,covalently,and irreversibly modifying the 12th cysteine residue of KRAS G12C.However,the pharmacokinetic profile of IBI351 in humans has not yet been reported.The current study aimed to investigate the pharmacokinetics and safety of IBI351 in healthy Chinese male subjects.A single oral dose of 600 mg combined with 150μCi[^(14)C]IBI351 was administered to six healthy male volunteers.Blood,urine,and fecal samples were collected at multiple time points to quantify the parent drug and its metabolites.IBI351 showed favorable pharmacokinetic characteristics and was well tolerated by all participants.Seventeen major metabolites were identified in plasma,urine,and feces.The main metabolic pathways included oxidation,hydrogenation,sulfonate conjugation,glucuronide conjugation,and cysteine conjugation.Excretion of IBI351 and its metabolites occurred mainly through feces.Collectively,this first-in-human study provides essential data on the metabolism and safety of IBI351 in Chinese subjects and lays the foundation for its further clinical development as a novel anti-tumor drug.展开更多
Marine protected areas(MPAs)play a critical role in maintaining marine ecosystem health,conserving biodiversity,and sustaining coastal livelihoods and socio-economic benefits.However,MPAs in China still face significa...Marine protected areas(MPAs)play a critical role in maintaining marine ecosystem health,conserving biodiversity,and sustaining coastal livelihoods and socio-economic benefits.However,MPAs in China still face significant design and management limitations,including a lack of a robust scientific basis for boundary delineation,weak enforcement capacity,poor adaptability to environmental and socio-economic changes,and insufficient integration of the ocean’s three-dimensional characteristics.These limitations are particularly evident in the context of climate change,overexploitation of marine resources,and the complex dynamics of ecosystems.This study systematically reviews the current status and challenges of MPAs in China,with a specific focus on the need for and benefits of dynamic and threedimensional protected areas for marine conservation.Dynamic protected areas,supported by real-time monitoring and flexible boundary adjustments,can more effectively respond to the migratory patterns of marine species and seasonal distribution shifts along China’s coast.On the other hand,three-dimensional protected areas enhance ecosystem protection by incorporating vertical ecological gradients and ocean depth,offering a vital complement to the predominantly two-dimensional protection approach currently in use.The study indicates that,with current technological and data capabilities,effective implementation of these advanced approaches requires precision marine observations,advanced analysis methods,and coordinated efforts among diverse stakeholders.In response,the study synthesizes multiple case studies to illustrate the potential ecological,managerial,and policy-related outcomes of dynamic and three-dimensional MPAs.It proposes strategies for optimization,implementation pathways,and targeted policy recommendations.Ultimately,the study emphasizes the critical role of scientific planning and technological innovation in enhancing the effectiveness of MPAs in China.It calls upon policymakers and the broader society to increase attention and investment in dynamic and three-dimensional marine conservation approaches.This work not only provides a scientific foundation for more precise and efficient marine governance in China,but also lays crucial foundation for achieving ocean-related sustainable development goals aligned with China’s national context.展开更多
The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved ...The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved N_(2)O from large regions such as the Southern Ocean.To address this deficit,N_(2)O was measured in the Prydz Bay in February 2015 during the 31st Chinese National Antarctic Research Expedition.N_(2)O concentrations(saturation)in the surface layer were generally low(undersaturation with respect to atmospheric equilibrium)and ranged from 13.3 nmol/L to 16.1 nmol/L(83%–102%)at the time of sampling.A comparison of our observations with archived data revealed that no discernible trend in N_(2)O concentrations in the surface waters of Prydz Bay could be detected for the period between 2006 and 2015.Temperature and salinity changes driven by meltwater input were the predominant controls on N_(2)O concentrations in surface waters.At depth,the distribution of N_(2)O concentrations was dominated by production via nitrification in offshore deep waters and vertical convection in the shelf waters,where concentrations were lower and gradients were less steep.Our results suggest a rather unusual pattern of N_(2)O distribution in the Prydz Bay(low N_(2)O in shelf waters compared with the open ocean),providing important insights into the coastal dynamics of N_(2)O in high-latitude polar regions.展开更多
The melting of seasonal sea ice in Antarctica plays a pivotal role in the region’s carbon cycle,influencing global carbon storage and the exchange of carbon between the atmosphere and the ocean.However,the impact of ...The melting of seasonal sea ice in Antarctica plays a pivotal role in the region’s carbon cycle,influencing global carbon storage and the exchange of carbon between the atmosphere and the ocean.However,the impact of variability in the timing of seasonal sea ice retreat on the flux and composition of sinking particulate matter remains to be elucidated.In this study,we deployed sediment traps in Prydz Bay during the austral summers of 2019/2020 and 2020/2021,noting that sea ice melting occurred approximately one and a half months earlier in the former summer compared to the latter.We analyzed sediment trap data,which included total mass flux(TMF),particulate organic carbon(POC),biogenic silica(BSi),particulate inorganic carbon,and lithogenic particle(Litho)fluxes,as well as the stable isotopesδ^(13)C andδ^(15)N of particulate organic matter(POM).Additionally,we incorporated remote sensing data on sea ice concentration and chlorophyll a.This dramatic delay in sea ice melting timing could result in a significant increase in TMF,BSi and POC fluxes in the summer of 2020/2021 compared to 2019/2020.Elevated BSi fluxes and more ^(13)C-depleted POC in the austral summer of 2020/2021 suggest that the delayed melting of sea ice may have stimulated the productivity of centric diatoms.Furthermore,the higher BSi/POC ratio and more negativeδ^(15)N values of POM,along with a reduced presence of krill in the traps,indicate a diminished grazing pressure from zooplankton,which collectively enhanced the sedimentation efficiency of POC during the austral summer of 2020/2021.These findings highlight the critical role of sea ice melting timing in regulating productivity,flux and composition of sinking particulate matter in the Prydz Bay ecosystem,with significant implications for carbon cycling in polar oceans.展开更多
Integral reinforcement learning(IRL)is an effective tool for solving optimal control problems of nonlinear systems,and it has been widely utilized in optimal controller design for solving discrete-time nonlinearity.Ho...Integral reinforcement learning(IRL)is an effective tool for solving optimal control problems of nonlinear systems,and it has been widely utilized in optimal controller design for solving discrete-time nonlinearity.However,solving the Hamilton-Jacobi-Bellman(HJB)equations for nonlinear systems requires precise and complicated dynamics.Moreover,the research and application of IRL in continuous-time(CT)systems must be further improved.To develop the IRL of a CT nonlinear system,a data-based adaptive neural dynamic programming(ANDP)method is proposed to investigate the optimal control problem of uncertain CT multi-input systems such that the knowledge of the dynamics in the HJB equation is unnecessary.First,the multi-input model is approximated using a neural network(NN),which can be utilized to design an integral reinforcement signal.Subsequently,two criterion networks and one action network are constructed based on the integral reinforcement signal.A nonzero-sum Nash equilibrium can be reached by learning the optimal strategies of the multi-input model.In this scheme,the NN weights are constantly updated using an adaptive algorithm.The weight convergence and the system stability are analyzed in detail.The optimal control problem of a multi-input nonlinear CT system is effectively solved using the ANDP scheme,and the results are verified by a simulation study.展开更多
Developing machine learning frameworks with predictive power,interpretability,and transferability is crucial,yet it faces challenges in the field of electrocatalysis.To achieve this,we employed rigorous feature engine...Developing machine learning frameworks with predictive power,interpretability,and transferability is crucial,yet it faces challenges in the field of electrocatalysis.To achieve this,we employed rigorous feature engineering to establish a finely tuned gradient boosting regressor(GBR)model,which adeptly captures the physical complexity from feature space to target variables.We demonstrated that environmental electron effects and atomic number significantly govern the success of the mapping process via global and local explanations.The finely tuned GBR model exhibits exceptional robustness in predicting CO adsorption energies(R_(ave)^(2)=0.937,RMSE=0.153 eV).Moreover,the model demonstrated remarkable transfer learning ability,showing excellent predictive power for OH,NO,and N_(2) adsorption.Importantly,the GBR model exhibits exceptional predictive capability across an extensive search space,thereby demonstrating profound adaptability and versatility.Our research framework significantly enhances the interpretability and transferability of machine learning in electrocatalysis,offering vital insights for further advancements.展开更多
Nutrient uptake status dominates phytoplankton biomass and community structure in the Southern Ocean during austral summer,yet how nutrient utilization variability responds to phytoplankton community succession is sti...Nutrient uptake status dominates phytoplankton biomass and community structure in the Southern Ocean during austral summer,yet how nutrient utilization variability responds to phytoplankton community succession is still unclear,partly due to lack of data spanning the entire summer.In this study,nitrate,phosphate,and silicate combined with temperature,salinity,and apparent oxygen utilization(AOU)were analyzed along 45°E in the Cosmonaut Sea during December 2019,January 2021,and February 2022.The variations in nutrient utilization in the euphotic layer were studied using biogeochemical tracers,and seasonal nutrient depletion was also estimated.The results showed that nutrient distribution varied significantly from December to February.Significant positive correlations were observed for nitrate and silicate concentrations with salinity and AOU,indicating that nutrient distributions were mainly influenced by water mass and phytoplankton production.Increasing∆[N*]and decreasing∆[Si*]in the upper 50 m were observed south of 63.5°S from December to February,which possibly contributed to a progressive shift in dominant phytoplankton population from Phaeocystis antarctica to diatoms.The seasonal nutrient depletion generally increased from December to February.Moreover,the consumption of silicate substantially increased compared to nitrate,indicating that the abundance of diatoms was increasing with time during the austral summer.Our observations suggest that nutrient utilization status is closely related to phytoplankton community structure in the euphotic layer of the Cosmonaut Sea.展开更多
Currently,various clinical treatment methods struggle to halt the rapid progression of common acute liver failure.To address this issue,significant advancements in stem cell derivatives and bioactive hydrogels in rege...Currently,various clinical treatment methods struggle to halt the rapid progression of common acute liver failure.To address this issue,significant advancements in stem cell derivatives and bioactive hydrogels in regenerative medicine have been utilized.A bioactive hydrogel with good tissue adhesion,CCO/HGF@EV,has been designed by incorporating cytokine hepatocyte growth factor(HGF),which plays a major role in the early regenerative phase of the liver,into stem cell-derived exosomal vesicles(EV)through electroporation.Under ultrasonic guidance,CCO/HGF@EV is administered near the liver,adhering firmly and degrading over three days to release HGF@EV.Through a series of rigorous experiments,it was confirmed that the abundant anti-inflammatory and regenerative cytokines in HGF@EV significantly reduced reactive oxygen species(ROS)during the acute phase of liver failure,alleviated hepatocyte apoptosis,decreased inflammatory damage and necrosis of liver tissue,and significantly promoted the regeneration and repair of liver parenchymal cells and vascular tissues.Additionally,the release of HGF after EV fusion with hepatocytes synergistically enhanced the regeneration of liver cells during the acute phase,thereby stabilizing liver function.This hydrogel,with its powerful therapeutic effects,forms a protective layer over the liver.It holds great potential for advancing research in tissue engineering and regenerative medicine and has significant clinical translational value.展开更多
基金supported by the National Key R&D Program of China(No.2021YFA1601003)the financial support of the SSRF PhaseⅡproject.
文摘This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline.
基金supported by the National Key R&D Program of China(No.2021YFB3700403).
文摘The hot deformation behavior of the premium GH4738 alloy was investigated in the temperature range of 1313 to 1353 K at strain rates of 0.01 to 1 s^(−1)using the hot compression test.To accurately predict flow stress,three novel strain compensation constitutive equations were developed and rigorously assessed.The results indicate that the power function model(correlation coefficients r=0.98544)demonstrates greater prediction accuracy compared to other functions,with a calculated average activation energy of 507.968 kJ mol−1.Additionally,electron backscattered diffraction technology and transmission electron microscopy were used to analyze the evolution of the alloy microstructure during dynamic recrystallization under different deformation conditions.The results show that under high-temperature and large deformation conditions,the dislocation density and the degree of grain rotation increase,which promotes the formation and growth of new recrystallized grains,so that recrystallization is completed when the deformation amount reaches 30%.Besides,the increase in the temperature not only enhances the thermal activation mechanism,but also improves the grain size uniformity and texture consistency.Meanwhile,the carbide inhibits grain overgrowth by pinning grain boundaries,maintaining a fine and uniform grain structure of the alloy,and thereby improving the plasticity of the material.
基金Supported by Jiangsu Commission of Health of China,No.M2020096.
文摘BACKGROUND Krüppel-like factor-5(KLF5)is a zinc-finger transcription factor related to tumor progression.However,the relationship between KLF5 and lung cancer remains to be identified.AIM To investigate the clinical value of KLF5 and interference with KLF5 mRNA transcription on the effects of biological behaviors in lung squamous-cell carcinoma(LUSC).METHODS Lung KLF5 mRNA data were extracted from bioinformatics databases.Blood and tissues from a cohort of patients with benign or malignant lung diseases were collected with ethical committee consent to validate KLF5 expression via multiplex immunofluorescence and immunohistochemistry,Western blot,Enzyme Linked Immunosorbent Assay or quantitative polymerase chain reaction.Furthermore,KLF5 mRNA was silenced in lung A549 cells to validate biological behaviors in vitro and nude mouse xenograft growth in vivo,respectively.RESULTS A cohort of bioinformatics databases revealed high KLF5 mRNA expression in LUSC(P<0.001)but lower KLF5 mRNA expression in lung adenocarcinoma.Upregulated KLF5 in the lung or sera of patients with lung cancer(P<0.001)were confirmed that related to poor differentiation,lymph node or distant metastasis.Furthermore,the incidence of KLF5 levels greater than 500 ng/mL in LUSC patients was 86.7%,which was significantly greater(P<0.001)than that in cases with benign lung diseases(13.3%)or healthy controls.Functionally,silencing KLF5 mRNA with a specific shRNA significantly suppressed A549 cell proliferation,decreased cell migration,increased the ratio of G2 phase cells in vitro,and inhibited the growth of nude mouse xenografts in vivo.CONCLUSION KLF5 is a novel diagnostic biomarker or potential therapeutic target for LUSC.
基金The National Polar Special Program under contract Nos IRASCC 01-01-02 and IRASCC 02-02the National Natural Science Foundation of China under contract Nos 41976228,42276255,41976227,42176227,and 42076243+1 种基金the International Cooperation Key Project of the Ministry of Science and Technology under contract No.2022YFE0136500the Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources,under contract Nos JG2011,JG2211,JG2013,and JG1805.
文摘Polynyas and their adjacent seasonal ice zones(SIZs)represent the most productive regions in the Southern Ocean,supporting unique food webs that are highly sensitive to climate change.Understanding the dynamics of phytoplankton and the carbon pool in these areas is crucial for assessing the role of the Southern Ocean in global carbon cycling.During the late stage of an algal bloom,seawater samples at 14 stations were collected in the Amundsen Sea Polynya(ASP)and adjacent SIZ.Using nutrients,phytoplankton pigments,organic carbon(OC),remote sensing data,and physicochemical measurements,as well as CHEMTAX model simulations,we investigated the response of the phytoplankton crops,taxonomic composition,and OC pool to environmental factors.Our analyses revealed that hydrodynamic regimes of the polynya,adjacent SIZs and open sea were regulated by the regionally varying intrusion of Circumpolar Deep Water,photosynthetically active radiation and sea ice melt water.The ASP exhibited the highest seasonal nutrient utilization rates[ΔN=(1059±386)mmol/m^(2),ΔP=(50±17)mmol/m^(2) andΔSi=(956±904)mmol/m^(2)],while the open sea had lower rates.The integrated chlorophyll a(Chl a)concentration at depths of 0–200 m ranged from 20.4 mg/m^(2) to 1420.0 mg/m^(2) and peaked in the polynya.In the study area,Haptophytes Phaeocystis antarctica was the dominant functional group(34%±27%),and diatoms acted as a secondary contributor(23%±14%).The major functional group and particulate OC(POC)contributor varied from diatoms(36%±12%)in the open sea to haptophytes(48%±31%)in the polynya waters.Strong light conditions and microelement limitations promoted the dominance of P.antarctica(low Fe forms)dominance in the ASP.The strong correlations between the POC and Chl a depth-integrated concentration suggest that the POC was primarily derived from phytoplankton,while dissolved OC(DOC)was influenced by consumer activity and water mass transport.In addition,the transport of OC in the upper 200 m of the water column within the ASP was quantified,revealing the predominantly westward fluxes for both DOC[9.0 mg/(m^(2)·s)]and POC[7.2 mg/(m^(2)·s)].The latitudinal transport exhibited the northward transport of DOC[8.1 mg/(m^(2)·s)]and southward transport of POC[4.3 mg/(m^(2)·s)]movement.These findings have significant implications for enhancing our understanding of how hydrodynamics influence OC cycling in polynya regions.
基金Supported by The National Natural Science Foundation of China,No.82470632.
文摘BACKGROUND Whether rtS106C+H126Y+D134E/rtS106C+H126Y+D134E+L269I(rtCYE/rtCYEI)mutations in the hepatitis B virus(HBV)reverse-transcriptase(RT)region are associated with tenofovir disoproxil fumarate(TDF)resistance is controversial.AIM To evaluate the presence of the rtCYE/rtCYEI mutations in a large cohort of Chinese patients with chronic HBV infection.METHODS A total of 28236 patients who underwent drug resistance testing at the Fifth Medical Center of Chinese PLA General Hospital from 2007 to 2019 were enrolled.All patients received nucleoside/nucleotide analogues(NAs)therapy,and serum samples were collected for sequence analysis of the HBV RT domain with mutation analysis.RESULTS The detection rates of a single mutation of rtS106C,rtH126Y,rtD134E,and rtL269I were 8.21%,3.20%,2.55%and 61.49%in 23718 genotype C patients,and 1.31%,1.76%,0.21%,and 92.33%in 4266 genotype B patients,respectively.The combined mutations of rtCYE/rtCYEI were only detected in 12 genotype C patients,accounting for 0.042%of all patients.These 12 patients had received NA treatments except TDF before testing.Among them,6 patients had coexisting rtCYE/rtCYEI and lamivudine-resistance mutations,and 2 patients had coexisting rtCYE/rtCYEI and adefovir-resistance mutations.Compared with the wild-type(WT)strain,the replication capacity of rtCYE/rtCYEI mutants from representative patients decreased by 41.1%-71.8%,and TDF susceptibility reduced by less than 2-fold,but rtCYEI+rtA181V/N236T mutants exhibited a 6.2-/9.9-fold decrease in TDF susceptibility.Molecular modeling showed that rtCYE/rtCYEI mutants had a slight decrease in binding energy to TDF compared to the WT strain.In the clinic,emergence of the rtCYE/rtCYEI mutations was not specifically associated with TDF treatment.CONCLUSION HBV rtCYE/rtCYEI mutations have a limited effect on TDF susceptibility and are not sufficient to cause TDF resistance.
基金supported by grant from Affiliated Hospital of Nantong University(YJXYY202204)Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX24_2063).
文摘Objective:Neuroblastoma(NB)is frequently associated with high-risk pediatric cases that demonstrate limited response to cisplatin,contributing to a poor prognosis.Recent studies have explored the role of tumor cell senescence in increasing sensitivity to this chemotherapy agent.This study aims to identify genes related to cell senescence in children diagnosed with NB,evaluate their influence on cisplatin sensitivity,and investigate potential strategies to enhance the efficacy of chemotherapy.Methods:Gene expression profiles and clinical data were obtained for 498 NB patients from the GEO database(GSE49710).The study focused on identifying genes that were differentially expressed between stage IV and other stages,particularly those linked to cell senescence and cisplatin resistance.To analyze the prognostic significance of these differentially expressed genes,we employed LASSO regression and multivariate Cox proportional hazards models.Transcriptomic and proteomic analyses of 15 NB specimens revealed a significant correlation between Flap endonuclease-1(FEN1)expression levels and both cellular senescence and sensitivity to cisplatin.We quantified FEN1 expression and cisplatin IC50 values in four different NB cell lines.The influence of FEN1 knockdown and overexpression on NB cell proliferation,invasion,and migration was evaluated using cloning assays,transwell assays,and scratch assays.Furthermore,we utilized Western blotting to analyze senescenceassociated proteins p21 and proliferating cell nuclear antigen(PCNA),thereby evaluating the role of FEN1 in cellular senescence.The impact of FEN1 on cisplatin sensitivity was investigated via the CCK-8 cell counting assay.Additionally,we investigated how FEN1 inhibitors might impact NB cell proliferation and enhance the therapeutic efficacy of cisplatin treatment.Results:FEN1 was found to be highly expressed in stage IV NB and showed a strong association with cisplatin sensitivity,establishing it as a critical molecular marker linked to poor patient prognosis.Notably,elevated FEN1 expression correlated with reduced sensitivity to cisplatin,as evidenced by higher IC50 values.In the SH-SY5Y cell line,FEN1 knockdown led to significant reductions in cell proliferation,invasion,and migration,along with an increase inβ-galactosidase staining—indicative of senescence.This knockdown also resulted in elevated levels of the p21 protein and decreased expression of PCNA,concurrently lowering cisplatin IC50 values.Conversely,FEN1 overexpression in the SK-N-SH cell line resulted in enhanced cell proliferation,invasion,and migration.This overexpression was associated with reducedβ-galactosidase staining,decreased levels of p21,and increased expression of PCNA,ultimately resulting in higher cisplatin IC50 values.Importantly,FEN1 inhibitors alone significantly impeded NB cell proliferation,and their combination with cisplatin further amplified this inhibitory effect compared to cisplatin treatment alone.Conclusions:Bioinformatics and sequencing analyses indicate that the senescence-related gene FEN1 is significantly associated with cisplatin sensitivity and adverse prognosis in pediatric NB.FEN1 plays a pivotal role in regulating NB cell proliferation,invasion,and migration,thereby facilitating cancer progression.Furthermore,it influences cisplatin sensitivity through its effects on cellular senescence.FEN1 inhibitors demonstrate potential both as monotherapies and in conjunction with cisplatin,suggesting that targeting FEN1 may be represent a valuable strategy for improving outcomes in high-risk NB patients.
基金the financial supports from the National Natural Science Foundation of China(52004096)Natural Science Foundation of Hebei Province(E2024209101)+2 种基金Hebei Province Science and Technology R&D Platform Construction Project(23560301D)Tangshan Science and Technology Bureau Project(23130202E)Graduate Student Innovation Fund of North China University of Science and Technology(CXZZBS2025150).
文摘In the traditional blast furnace(BF)ironmaking process in China,a notable deviation exists between the theoretical and actual yield of hot metal,leading to unexpected iron loss and restricting the improvement of production capacity,which cannot adapt to the increasingly intensified smelting rhythm.Focusing on a BF in a Chinese steel enterprise,a deep neural network algorithm was designed to model the impact of multiple parameters on actual yield of hot metal in a single BF smelting cycle,successfully accomplishing the theoretical computation and real-time prediction of yield of hot metal for subsequent,unknown BF smelting cycle.Test results show that the proposed algorithm demonstrates an impressive prediction accuracy of 86.7% within an error range of±10 t and can swiftly complete the training and convergence process in 32.5 s.By integrating prediction results with Nomogram,a regulatory mechanism was engineered to minimize the deviation between theoretical and actual yield of hot metal.This mechanism ensures the yield enhancement of hot metal through dynamic adjustments of BF operational parameters.Industrial-scale application experiments confirmed that the intelligent operation and optimization system,developed in the laboratory,can maintain the yield deviation of hot metal within a stable range of 30 t,achieving a maximum reduction in iron loss rate of 17.65%compared to that before system operation.The findings provide robust support for the yield increase and efficiency improvement of the experimental BF.
基金supported by funding from the 13th Five-Year Plan New Drug Creation Program—Isotope Tracer Technology Platform for Clinical Evaluation of Innovative Drugs(Grant No.2017ZX09304032 with project leaders Jun Zhao and Chen Zhou).
文摘IBI351,a synthetic compound,exerts its anti-tumor effects by specifically,covalently,and irreversibly modifying the 12th cysteine residue of KRAS G12C.However,the pharmacokinetic profile of IBI351 in humans has not yet been reported.The current study aimed to investigate the pharmacokinetics and safety of IBI351 in healthy Chinese male subjects.A single oral dose of 600 mg combined with 150μCi[^(14)C]IBI351 was administered to six healthy male volunteers.Blood,urine,and fecal samples were collected at multiple time points to quantify the parent drug and its metabolites.IBI351 showed favorable pharmacokinetic characteristics and was well tolerated by all participants.Seventeen major metabolites were identified in plasma,urine,and feces.The main metabolic pathways included oxidation,hydrogenation,sulfonate conjugation,glucuronide conjugation,and cysteine conjugation.Excretion of IBI351 and its metabolites occurred mainly through feces.Collectively,this first-in-human study provides essential data on the metabolism and safety of IBI351 in Chinese subjects and lays the foundation for its further clinical development as a novel anti-tumor drug.
基金The National Natural Science Foundation of China under contract No.42176173.
文摘Marine protected areas(MPAs)play a critical role in maintaining marine ecosystem health,conserving biodiversity,and sustaining coastal livelihoods and socio-economic benefits.However,MPAs in China still face significant design and management limitations,including a lack of a robust scientific basis for boundary delineation,weak enforcement capacity,poor adaptability to environmental and socio-economic changes,and insufficient integration of the ocean’s three-dimensional characteristics.These limitations are particularly evident in the context of climate change,overexploitation of marine resources,and the complex dynamics of ecosystems.This study systematically reviews the current status and challenges of MPAs in China,with a specific focus on the need for and benefits of dynamic and threedimensional protected areas for marine conservation.Dynamic protected areas,supported by real-time monitoring and flexible boundary adjustments,can more effectively respond to the migratory patterns of marine species and seasonal distribution shifts along China’s coast.On the other hand,three-dimensional protected areas enhance ecosystem protection by incorporating vertical ecological gradients and ocean depth,offering a vital complement to the predominantly two-dimensional protection approach currently in use.The study indicates that,with current technological and data capabilities,effective implementation of these advanced approaches requires precision marine observations,advanced analysis methods,and coordinated efforts among diverse stakeholders.In response,the study synthesizes multiple case studies to illustrate the potential ecological,managerial,and policy-related outcomes of dynamic and three-dimensional MPAs.It proposes strategies for optimization,implementation pathways,and targeted policy recommendations.Ultimately,the study emphasizes the critical role of scientific planning and technological innovation in enhancing the effectiveness of MPAs in China.It calls upon policymakers and the broader society to increase attention and investment in dynamic and three-dimensional marine conservation approaches.This work not only provides a scientific foundation for more precise and efficient marine governance in China,but also lays crucial foundation for achieving ocean-related sustainable development goals aligned with China’s national context.
基金The National Natural Science Foundation of China under contract No.41906193the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources,under contract No.2019033+2 种基金the Natural Science Foundation of Fujian Province under contract No.2019J05147the Federal Ministry of Education and Research of Germany under contract No.FKZ 03F03F0783Athe National Polar Special Program under contract Nos IRASCC 01-01-02 and IRASCC 02-02.
文摘The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved N_(2)O from large regions such as the Southern Ocean.To address this deficit,N_(2)O was measured in the Prydz Bay in February 2015 during the 31st Chinese National Antarctic Research Expedition.N_(2)O concentrations(saturation)in the surface layer were generally low(undersaturation with respect to atmospheric equilibrium)and ranged from 13.3 nmol/L to 16.1 nmol/L(83%–102%)at the time of sampling.A comparison of our observations with archived data revealed that no discernible trend in N_(2)O concentrations in the surface waters of Prydz Bay could be detected for the period between 2006 and 2015.Temperature and salinity changes driven by meltwater input were the predominant controls on N_(2)O concentrations in surface waters.At depth,the distribution of N_(2)O concentrations was dominated by production via nitrification in offshore deep waters and vertical convection in the shelf waters,where concentrations were lower and gradients were less steep.Our results suggest a rather unusual pattern of N_(2)O distribution in the Prydz Bay(low N_(2)O in shelf waters compared with the open ocean),providing important insights into the coastal dynamics of N_(2)O in high-latitude polar regions.
基金The National Key Research and Development Program of China under contract No.2022YFE0136500the Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources,under contract Nos JG2212 and JG2211+2 种基金the National Natural Science Foundation of China under contract Nos 42276255,41976228,and 42176227the National Polar Special Program“Impact and Response of Antarctic Seas to Climate Change”under contract Nos IRASCC 01-01-02 and IRASCC 02-02the China Scholarship Council under contract No.201704180017.
文摘The melting of seasonal sea ice in Antarctica plays a pivotal role in the region’s carbon cycle,influencing global carbon storage and the exchange of carbon between the atmosphere and the ocean.However,the impact of variability in the timing of seasonal sea ice retreat on the flux and composition of sinking particulate matter remains to be elucidated.In this study,we deployed sediment traps in Prydz Bay during the austral summers of 2019/2020 and 2020/2021,noting that sea ice melting occurred approximately one and a half months earlier in the former summer compared to the latter.We analyzed sediment trap data,which included total mass flux(TMF),particulate organic carbon(POC),biogenic silica(BSi),particulate inorganic carbon,and lithogenic particle(Litho)fluxes,as well as the stable isotopesδ^(13)C andδ^(15)N of particulate organic matter(POM).Additionally,we incorporated remote sensing data on sea ice concentration and chlorophyll a.This dramatic delay in sea ice melting timing could result in a significant increase in TMF,BSi and POC fluxes in the summer of 2020/2021 compared to 2019/2020.Elevated BSi fluxes and more ^(13)C-depleted POC in the austral summer of 2020/2021 suggest that the delayed melting of sea ice may have stimulated the productivity of centric diatoms.Furthermore,the higher BSi/POC ratio and more negativeδ^(15)N values of POM,along with a reduced presence of krill in the traps,indicate a diminished grazing pressure from zooplankton,which collectively enhanced the sedimentation efficiency of POC during the austral summer of 2020/2021.These findings highlight the critical role of sea ice melting timing in regulating productivity,flux and composition of sinking particulate matter in the Prydz Bay ecosystem,with significant implications for carbon cycling in polar oceans.
文摘Integral reinforcement learning(IRL)is an effective tool for solving optimal control problems of nonlinear systems,and it has been widely utilized in optimal controller design for solving discrete-time nonlinearity.However,solving the Hamilton-Jacobi-Bellman(HJB)equations for nonlinear systems requires precise and complicated dynamics.Moreover,the research and application of IRL in continuous-time(CT)systems must be further improved.To develop the IRL of a CT nonlinear system,a data-based adaptive neural dynamic programming(ANDP)method is proposed to investigate the optimal control problem of uncertain CT multi-input systems such that the knowledge of the dynamics in the HJB equation is unnecessary.First,the multi-input model is approximated using a neural network(NN),which can be utilized to design an integral reinforcement signal.Subsequently,two criterion networks and one action network are constructed based on the integral reinforcement signal.A nonzero-sum Nash equilibrium can be reached by learning the optimal strategies of the multi-input model.In this scheme,the NN weights are constantly updated using an adaptive algorithm.The weight convergence and the system stability are analyzed in detail.The optimal control problem of a multi-input nonlinear CT system is effectively solved using the ANDP scheme,and the results are verified by a simulation study.
基金supported by the Research Grants Council of Hong Kong(CityU 11305919 and 11308620)and NSFC/RGC Joint Research Scheme N_CityU104/19Hong Kong Research Grant Council Collaborative Research Fund:C1002-21G and C1017-22Gsupported by the Hong Kong Research Grant Council Collaborative Research Fund:C6021-19E.
文摘Developing machine learning frameworks with predictive power,interpretability,and transferability is crucial,yet it faces challenges in the field of electrocatalysis.To achieve this,we employed rigorous feature engineering to establish a finely tuned gradient boosting regressor(GBR)model,which adeptly captures the physical complexity from feature space to target variables.We demonstrated that environmental electron effects and atomic number significantly govern the success of the mapping process via global and local explanations.The finely tuned GBR model exhibits exceptional robustness in predicting CO adsorption energies(R_(ave)^(2)=0.937,RMSE=0.153 eV).Moreover,the model demonstrated remarkable transfer learning ability,showing excellent predictive power for OH,NO,and N_(2) adsorption.Importantly,the GBR model exhibits exceptional predictive capability across an extensive search space,thereby demonstrating profound adaptability and versatility.Our research framework significantly enhances the interpretability and transferability of machine learning in electrocatalysis,offering vital insights for further advancements.
基金The National Polar Special Program“Impact and Response of Antarctic Seas to Climate Change”under contract Nos IRASCC 01-01-02 and IRASCC 02-02the National Key Research and Development Program of China under contract No.2022YFE0136500+1 种基金the National Natural Science Foundation of China(NSFC)under contract Nos 41976228,42276255 and 42176227the Scientific Research Fund of the Second Institute of Oceanography under contract Nos JG2011,JG2211 and JG2013.
文摘Nutrient uptake status dominates phytoplankton biomass and community structure in the Southern Ocean during austral summer,yet how nutrient utilization variability responds to phytoplankton community succession is still unclear,partly due to lack of data spanning the entire summer.In this study,nitrate,phosphate,and silicate combined with temperature,salinity,and apparent oxygen utilization(AOU)were analyzed along 45°E in the Cosmonaut Sea during December 2019,January 2021,and February 2022.The variations in nutrient utilization in the euphotic layer were studied using biogeochemical tracers,and seasonal nutrient depletion was also estimated.The results showed that nutrient distribution varied significantly from December to February.Significant positive correlations were observed for nitrate and silicate concentrations with salinity and AOU,indicating that nutrient distributions were mainly influenced by water mass and phytoplankton production.Increasing∆[N*]and decreasing∆[Si*]in the upper 50 m were observed south of 63.5°S from December to February,which possibly contributed to a progressive shift in dominant phytoplankton population from Phaeocystis antarctica to diatoms.The seasonal nutrient depletion generally increased from December to February.Moreover,the consumption of silicate substantially increased compared to nitrate,indicating that the abundance of diatoms was increasing with time during the austral summer.Our observations suggest that nutrient utilization status is closely related to phytoplankton community structure in the euphotic layer of the Cosmonaut Sea.
基金supported by the Fellowship of China Postdoctoral Science Foundation(No.2023M732299)。
文摘Currently,various clinical treatment methods struggle to halt the rapid progression of common acute liver failure.To address this issue,significant advancements in stem cell derivatives and bioactive hydrogels in regenerative medicine have been utilized.A bioactive hydrogel with good tissue adhesion,CCO/HGF@EV,has been designed by incorporating cytokine hepatocyte growth factor(HGF),which plays a major role in the early regenerative phase of the liver,into stem cell-derived exosomal vesicles(EV)through electroporation.Under ultrasonic guidance,CCO/HGF@EV is administered near the liver,adhering firmly and degrading over three days to release HGF@EV.Through a series of rigorous experiments,it was confirmed that the abundant anti-inflammatory and regenerative cytokines in HGF@EV significantly reduced reactive oxygen species(ROS)during the acute phase of liver failure,alleviated hepatocyte apoptosis,decreased inflammatory damage and necrosis of liver tissue,and significantly promoted the regeneration and repair of liver parenchymal cells and vascular tissues.Additionally,the release of HGF after EV fusion with hepatocytes synergistically enhanced the regeneration of liver cells during the acute phase,thereby stabilizing liver function.This hydrogel,with its powerful therapeutic effects,forms a protective layer over the liver.It holds great potential for advancing research in tissue engineering and regenerative medicine and has significant clinical translational value.
