Nonhuman primates are increasingly being used as animal models in neuroscience research.However,efficient neuronal tracing techniques for labeling motor neurons and primary sensory afferents in the monkey spinal cord ...Nonhuman primates are increasingly being used as animal models in neuroscience research.However,efficient neuronal tracing techniques for labeling motor neurons and primary sensory afferents in the monkey spinal cord are lacking.Here,by injecting the cholera toxin B subunit into the sciatic nerve of a rhesus monkey,we successfully labeled the motor neurons and primary sensory afferents in the lumbar and sacralspinal cord.Labeled alpha motor neurons were located in lamina IX of the L6–S1 segments,which innervate both flexors and extensors.The labeled primary sensory afferents were mainly myelinated Aβfibers that terminated mostly in laminae I and II of the L4–L7 segments.Together with the labeled proprioceptive afferents,the primary sensory afferents formed excitatory synapses with multiple types of spinal neurons.In summary,our methods successfully traced neuronal connections in the monkey spinal cord and can be used in spinal cord studies when nonhuman primates are used.展开更多
The safety of safe crop products （SCP） is critical to maintain people＇s health and living standard. With the global efforts on the improvement of the traceability of food products, it is inevitable to establish cor...The safety of safe crop products （SCP） is critical to maintain people＇s health and living standard. With the global efforts on the improvement of the traceability of food products, it is inevitable to establish corresponding traceability systems to monitor the safety of crop products in China. In this article, the supply chain pattern of SCP in China has been analyzed and its spatial characters have been described in detail. The study deals with on how to relate traceability technology with GIS, and on how to trace and retrace the safety of SCP using the function of excellent spatial representation, spatial locating, and spatial analysis provided in GIS, which has been discussed from several aspects, such as coding technique of traceability information, transferring technique of traceability information, spatialization of traceability information, and application integration of traceability system. A pilot study was carried out to present the basic functions of the system, which provided an efficient and credible way to trace and retrace the safety of SCP in a real supply chain. An innovative idea has been brought forward for how to establish an efficient, credible, applied traceability system of SCP.展开更多
In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant attention.Knowledge tracing(KT)plays a pivotal role in this field by pred...In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant attention.Knowledge tracing(KT)plays a pivotal role in this field by predicting students’future performance through the analysis of historical interaction data,thereby assisting educators in evaluating knowledgemastery and tailoring instructional strategies.Traditional knowledge tracingmethods,largely based on Recurrent Neural Networks(RNNs)and Transformer models,primarily focus on capturing long-term interaction patterns in sequential data.However,these models may neglect crucial short-term dynamics and other relevant features.This paper introduces a novel approach to knowledge tracing by leveraging a pure Multilayer Perceptron(MLP)architecture.We proposeMixerKT,a knowledge tracing model based on theHyperMixer framework,which uniquely integrates global and localMixer feature extractors.This architecture enables more effective extraction of both long-terminteraction trends and recent learning behaviors,addressing limitations in currentmodels thatmay overlook these key aspects.Empirical evaluations on twowidely-used datasets,ASSIS Tments2009 and Algebra2005,demonstrate that MixerKT consistently outperforms several state-of-the-art models,including DKT,SAKT,and Separated Self-Attentive Neural Knowledge Tracing(SAINT).Specifically,MixerKT achieves higher prediction accuracy,highlighting its effectiveness in capturing the nuances of learners’knowledge states.These results indicate that our model provides a more comprehensive representation of student learning patterns,enhancing the ability to predict future performance with greater precision.展开更多
Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate ...Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics.展开更多
This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples w...This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples were taken from a depth of 0 to 20 cm using a hand auger on both banks of five tributaries of the Congo River (Djoué, Mfilou, Mfoa, Tsiémé, Djiri) that flow through the city of Brazzaville. 90 sampling points were defined, with 3 points 250 m apart on the banks and located, for each river, at three sites: upstream, midstream and downstream. Finally, 15 composite samples representative of the study area were taken. The average pH values of the water varied between 6.5 and 7.5. These pH values show that the soils studied are neutral. Total carbon content varied between 0.7% (Djiri) and 1.6% (Djoué). Total nitrogen content ranged from 0.08% (Djiri) to 0.12% (Djoué). TMEs contents varied from 0.5 to 1.8 mg/kg for Sb, from 0.5 to 2.5 mg/kg for As, from 0.1 to 0.18 mg/kg for Cd, from 4.2 to 11.3 mg/kg for Cr, from 0.07 to 0.27 mg/kg for Hg, from 0.7 to 2.4 mg/kg for Ni, from 0 to 158 mg/kg for Pb and from 16 to 105 mg/kg for Zn. The lowest TMEs levels were observed in the soils of the Djiri river, while the highest levels were observed in the soils of the Djoué and Tsiémé rivers. The ANOVA and Bonferroni test did not show significant differences in the means of the parameters measured (p > 0.05). The TMEs levels were below the accepted standards (NF U44-041), with the exception of Pb, which had high levels downstream of the Djoué. According to the pollution index values calculated using soil TME content, the soils on the banks of the Djoué river are considered polluted, while those on the banks of the Tsiémé river are moderately polluted, those on the banks of the Mfoa and Mfilou rivers are slightly polluted, and the soils on the banks of Djiri river are unpolluted.展开更多
The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace K...The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.展开更多
Introduction: During pregnancy, the increased demand for all the nutrients required for the development of the foetus means that the maternal stock of trace elements and minerals may become unbalanced if dietary intak...Introduction: During pregnancy, the increased demand for all the nutrients required for the development of the foetus means that the maternal stock of trace elements and minerals may become unbalanced if dietary intake fails to compensate. The aim of this research is to determine the status of trace elements (calcium, copper, magnesium, selenium and zinc) in pregnant women in the city of Kisangani. Methods: We carried out an analytical cross-sectional study of non-pregnant and pregnant women living in Kisangani, from 05 October 2023 to 05 January 2024. Concentrations of trace elements in sera were analysed using an inductively coupled plasma mass spectrophotometer (ICP-MS Agilent 7700X). Statistical analysis of the data was performed using R software version 4.3.0. Results: The mean age was 26.3 ± 6.7 years;the mean copper and magnesium levels in the serum of pregnant women were 12.58 ± 1.13 micromol/l and 1.03 ± 1.03 mmol/l respectively. The medians for calcium and zinc were 1.49 mmol/l and 8.42 micromol/l. The selenium mode was 0.41 micromol/l. Variations in trace element levels in sera of pregnant women were 0.94 - 2.22 mmol/l for calcium;0.31 - 0.78 micromol/l for selenium;and 7.29 - 12.72 micromol/l for zinc;11.04 - 14.99 micromol/l for copper, and 0.082 - 1.05 mmol/l for magnesium. Conclusion: Serum trace element concentrations in pregnant women were lower than those observed in non-pregnant women. Trace element reserves in pregnant women depended on their nutrient status prior to pregnancy, hence, there was an urgent need for trace element balance prior to pregnancy.展开更多
The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism,carbonate sedimentation,and deposition of a thick s...The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism,carbonate sedimentation,and deposition of a thick salt layer.The carbonates underlying the salt layer(pre-salt carbonates)were formed in restricted lacustrine basins.Here,the timing and fluid sources of deposition,diagenetic,and hydrothermal alterations of the pre-salt carbonate rocks are defined through in-situ U-Pb dating,87Sr/86Sr,and trace element analyses of samples from the Santos Basin.The very alkaline nature of the Aptian lake(s)produced characteristically unique and widely distributed carbonate rocks such as Mg-clays with calcite spherulite and calcite crystal shrub limestones transitioning laterally and vertically into travertines formed by hydrothermal pulses during basin evolution.Hydrothermalism caused extensive replacement,dissolution,and calcite cementation.REE+Y PAAS-normalised patterns and 87Sr/86Sr ratios indicate that deposition/eo-diagenesis of the primary carbonates occurred in a lacustrine environment primarily controlled by evaporation,pH,and continental water source,with 2%–10%hydrothermal fluid input.Trace elements and Sr-isotope of travertines and burial diagenetic phases show that they are produced from a hot mixture of mafic/mantle-derived fluids and dissolution/alteration of older carbonate formations.U-Pb dating indicates that carbonate deposition occurred between 124.8±2.6 Ma and 120.0±1.6 Ma,earlier than previously proposed,followed closely by the circulation of hydrothermal fluids.Replacement and cementation ages range from 120.5±2.4 Ma to 80.4±2.4 Ma.展开更多
This review systematically summarizes the core advances in the field of trace elements and tumors,and clarifies the dual roles of key elements such as Zn,Cu,Fe,Se,Mn,and Ni in tumorigenesis(e.g.,DNA damage repair),tum...This review systematically summarizes the core advances in the field of trace elements and tumors,and clarifies the dual roles of key elements such as Zn,Cu,Fe,Se,Mn,and Ni in tumorigenesis(e.g.,DNA damage repair),tumor progression(e.g.,tumor microenvironment regulation),and therapeutic response-these elements not only possess tumor-suppressive potential but can also contribute to tumorigenesis.Meanwhile,it confirms the breakthrough value of multi-omics technologies and organoid models in deciphering the“element-cell-tumor”interaction mechanisms,which overcomes the limitations of traditional in vitro experiments and also points out the core directions for subsequent clinical research.展开更多
It is of great importance to obtain precise trace data,as traces are frequently the sole visible and measurable parameter in most outcrops.The manual recognition and detection of traces on high-resolution three-dimens...It is of great importance to obtain precise trace data,as traces are frequently the sole visible and measurable parameter in most outcrops.The manual recognition and detection of traces on high-resolution three-dimensional(3D)models are relatively straightforward but time-consuming.One potential solution to enhance this process is to use machine learning algorithms to detect the 3D traces.In this study,a unique pixel-wise texture mapper algorithm generates a dense point cloud representation of an outcrop with the precise resolution of the original textured 3D model.A virtual digital image rendering was then employed to capture virtual images of selected regions.This technique helps to overcome limitations caused by the surface morphology of the rock mass,such as restricted access,lighting conditions,and shading effects.After AI-powered trace detection on two-dimensional(2D)images,a 3D data structuring technique was applied to the selected trace pixels.In the 3D data structuring,the trace data were structured through 2D thinning,3D reprojection,clustering,segmentation,and segment linking.Finally,the linked segments were exported as 3D polylines,with each polyline in the output corresponding to a trace.The efficacy of the proposed method was assessed using a 3D model of a real-world case study,which was used to compare the results of artificial intelligence(AI)-aided and human intelligence trace detection.Rosette diagrams,which visualize the distribution of trace orientations,confirmed the high similarity between the automatically and manually generated trace maps.In conclusion,the proposed semi-automatic method was easy to use,fast,and accurate in detecting the dominant jointing system of the rock mass.展开更多
Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with ...Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.展开更多
Quartz trace elements are extensively employed in studying magmatic evolution,fluid evolution,and metal enrichment.The Bianjiadayuan Ag-Pb-Zn-Sn deposit is a typical magmatichydrothermal system in northeastern China,h...Quartz trace elements are extensively employed in studying magmatic evolution,fluid evolution,and metal enrichment.The Bianjiadayuan Ag-Pb-Zn-Sn deposit is a typical magmatichydrothermal system in northeastern China,however,studies on its complex magmatic-hydrothermal evolution are limited.This study investigates the quartz from the Bianjiadayuan deposit to gain insight into the physicochemical evolution of mineralization using cathodoluminescence(CL)textures and laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)of quartz.Five types quartz(Q1 to Q5)were identified.From Q1 in quartz porphyry to Q5 in Ag-Pb-Zn veins,the CL intensity and Ti content gradually decreases,and Ge,Ge/Ti,and Al/Ti ratios increase,indicating a temperature decline from magmatic to hydrothermal stages.The Sb content shows an opposite trend to Ti content,correlating positively with Ge content in quartz,suggesting that Sb content could also be temperature-dependent.These trace elements in quartz indicate cooling is critical for Ag mineralization.Furthermore,quartz phenocryst(Q1)from the quartz porphyry shows low Al/Ti(mostly<4)and Ge/Ti ratios(<0.04),suggesting a low degree of magmatic evolution.The Sb content in Q5 from Ag-Pb-Zn-quartz veins(>1 ppm,mostly tens of ppm)is notably higher compared to quartz in other lithologies including Sn-bearing quartz veins(<1 ppm),suggesting that Sb contents can serve as an effective indicator of Ag mineralization.展开更多
Field-and petrographic investigations,together with microanalytical major-and traceelement studies,were carried out on clinopyroxene and amphibole from high-Mg diorite in the subduction-related Chelyabinsk granitic ma...Field-and petrographic investigations,together with microanalytical major-and traceelement studies,were carried out on clinopyroxene and amphibole from high-Mg diorite in the subduction-related Chelyabinsk granitic massif to understand its petrogenesis and source.The clinopyroxene composition(high Mg#,Cr-content,sum of REE and Ti/Eu ratio;depletion in HREE;negative Eu-anomaly)indicates that it formed from a reduced melt derived from a mantle source metasomatized by fluids/melts having crustal affinity.Melt compositions in equilibrium with clinopyroxene and amphibole were calculated using solid/liquid partition coefficients.The high Nb/Y and Zr/Y ratio values of a liquid simulated from clinopyroxene,which appears to have very similar characteristics to sanukitoid melts,indicate a low degree of melting of the mantle source.Melt simulated from amphibole is more evolved and more felsic(dacitic).It displays a geochemical“amphibole fractionation”signature,indicating the peritectic transformation of clinopyroxene to amphibole in the lower crust.Rock textures and major element mineral compositions suggest that further amphibole was precipitated directly from the melt in the middle crust.The results show that the Chelyabinsk highMg diorite was probably formed as a cumulate from sanukitoid-like melt during its ascent and cooling below dacitic liquidus inside the amphibole stability field.展开更多
We investigated the concentrations,vertical distribution,and enrichment status of ten trace metal elements(Cr,Hg,Cu,Pb,Zn,Cd,As,Co,V,and Ni)in sediments of core D04 from the muddy area outside the Oujiang River Estuar...We investigated the concentrations,vertical distribution,and enrichment status of ten trace metal elements(Cr,Hg,Cu,Pb,Zn,Cd,As,Co,V,and Ni)in sediments of core D04 from the muddy area outside the Oujiang River Estuary.In addition to V,As,and Hg,the concentrations of Cr,Cu,Zn,Pb,Cd,Ni and Co were constrained by sediment grain size and organic matter.Al-though the concentrations of trace metals fluctuated during the 5.8–2.5 kyr BP period,overall variations remained relatively stable.However,during the 2.5–0 kyr BP period,the concentrations of Cd,Zn,Cu,Pb,Ni,Ni,and Cr showed an increasing trend within the fluctuations,ultimately reaching relatively high levels.The muddy area was lightly contaminated by heavy metals such as As,Hg,and Cu.The concentrations of Hg,As,and Cu have been continuously increasing since 2.5 kyr BP,indicating clear impacts from fre-quent human activities.展开更多
Polyethylene oxide(PEO)-based solid-state polymer electrolytes(SPE)face the challenges of insufficient ionic conductivity and uncontrollable Li dendrite growth.The filler strategy can reinforce anode interface stabili...Polyethylene oxide(PEO)-based solid-state polymer electrolytes(SPE)face the challenges of insufficient ionic conductivity and uncontrollable Li dendrite growth.The filler strategy can reinforce anode interface stability,but at the cost of a large filler content(usually more than 10 wt%).This would increase the granular sensation,gravitational separation risk,and electrolyte membrane roughness with the creation of inhomogeneous Li^(+)transport channels between filler and polymer.Herein,we propose a trace filling strategy to address the above problems by introducing an amphoteric molecule L-Cysteine(LCy)as an eco-friendly and low-cost electrolyte additive.Only trace amount of LCy is required and integrated into PEO to form a homogenous,granule-less SPE with enhanced ionic conductivity and dendrite suppression capability.The ionic conductivity increases to 0.54 mS cm^(-1)at 60℃ after introducing only 1 wt%LCy.The amphotericity of LCy with basic–NH_(2)and acidic–COOH groups can promote the dissociation of Li salt and release more free Li ions through Lewis acid-base synergy,as well as the formation of multiple hydrogen bonds between PEO and LCy.The trace LCy additive swiftly leads to the formation of more ionic conductive interphases at both the anode and cathode sides.The composite SPE enables the stable cycling of Li metal for over 1400 h at 0.2 mA cm^(-2)and sustains a maximum current density up to 1.4 mA cm^(-2)in Li Li symmetric cells.The corresponding all-solid-state Li||FeF_(3)full cells exhibit a high specific capacity up to 567 mA h g^(-1)at 0.2 C and stable cycling performance for at least 700 cycles at 0.5 C with a high capacity retention.The excellent interface compatibility also guarantees the achievement of highcapacity Li-Fe-F conversion reaction even under the thin electrolyte membrane thickness and largerscale pouch cell configuration.展开更多
Halogenated aromatic disinfection byproducts(DBPs)are gradually receiving attention due to their high detection frequency and usually higher toxicity than regulated DBPs.In this study,we established a solid phase extr...Halogenated aromatic disinfection byproducts(DBPs)are gradually receiving attention due to their high detection frequency and usually higher toxicity than regulated DBPs.In this study,we established a solid phase extraction(SPE)-LC-MS/MS method to simultaneously trace analyze 59 halogenated aromatic DBPs.The limits of detection and limits of quantification of halogenated aromatic DBPs ranged from 0.03 to 135.23 ng/L and from 0.1 to 450.76 ng/L,respectively.The range of recoveries and relative standard deviation(RSD)in river water were between 72.41%to 119.54%and 1.86%to 16.03%,respectively.Therefore,this method can be used to accurately analyze trace levels of halogenated aromatic DBPs in drinking water.The occurrence and transformation of halogenated aromatic DBPs were explored based on this method.In the chlorinated simulated source water and chlorinated river water,20 and 45 halogenated aromatic DBPs were determined,respectively.The active halogen species(HOCl,HOBr,and HOI)first reacted with natural organic matter(NOM)to form halogenated aromatic DBPs.Then,chlorine further reacted with the halogenated aromatic DBPs to convert them into small-molecule halogenated aliphatic DBPs through oxidation,electrophilic substitution,and hydrolysis reaction,etc.In the chlorinated simulated source water,chlorinated river water,and tap water,the toxicity contribution of bromoacetic acids(Br-HAAs)accounted for themajority(>71.16%).Given that halogenated aromatic DBPs are intermediate products of halogenated aliphatic DBPs,controlling the formation of halogenated aromatic DBPs is beneficial in decreasing the formation of halogenated aliphatic DBPs,thereby diminishing the toxicity of drinking water.展开更多
With the rapid advancement of medical artificial intelligence(AI)technology,particularly the widespread adoption of AI diagnostic systems,ethical challenges in medical decision-making have garnered increasing attentio...With the rapid advancement of medical artificial intelligence(AI)technology,particularly the widespread adoption of AI diagnostic systems,ethical challenges in medical decision-making have garnered increasing attention.This paper analyzes the limitations of algorithmic ethics in medical decision-making and explores accountability mechanisms,aiming to provide theoretical support for ethically informed medical practices.The study highlights how the opacity of AI algorithms complicates the definition of decision-making responsibility,undermines doctor-patient trust,and affects informed consent.By thoroughly investigating issues such as the algorithmic“black box”problem and data privacy protection,we develop accountability assessment models to address ethical concerns related to medical resource allocation.Furthermore,this research examines the effective implementation of AI diagnostic systems through case studies of both successful and unsuccessful applications,extracting lessons on accountability mechanisms and response strategies.Finally,we emphasize that establishing a transparent accountability framework is crucial for enhancing the ethical standards of medical AI systems and protecting patients’rights and interests.展开更多
The measurement of trace elements in Antarctic snow is crucial for understanding historical atmospheric geochemical changes and circulation patterns.However,studies on their spatial distributions remain limited,partic...The measurement of trace elements in Antarctic snow is crucial for understanding historical atmospheric geochemical changes and circulation patterns.However,studies on their spatial distributions remain limited,particularly those evaluating multiple metals across several snowpits,making interpretation challenging.This study investigates the distributions and sources of trace elements-including Cd,Ba,Pb,U,Bi,V,Mn,Fe,Cu,Zn,and As-across four snowpits in the Lambert Glacier Basin,East Antarctica.The trace elements exhibit site-,element-,and season-dependent variations,with higher concentrations observed at inland sites.In contrast,δ^(18)O and ion concentrations decrease with increasing distance from the coast and elevation,underscoring the influence of marine emissions.Crustal sources primarily contributed to Ba,U,V,Mn,and Fe,while non-crustal sources predominantly contributed to Cd,Bi,Zn,Pb,Cu,and As.Positive matrix factorization(PMF)analysis indicates that trace element concentrations in Pits 2 and 3 are influenced by both crustal and non-crustal sources,while Pit 4 reflects a mixed-source influence.Pit 1(coastal site)also indicates the mixed sources with influence of a highly dynamic marine climate and environment.The PMF results reveal similarities in emission sources and atmospheric transport patterns across the snowpits,facilitating a more comprehensive interpretation of longer ice core records.Overall,this study provides valuable insights into trace element distributions and enhances our understanding of past environmental and climatic conditions.展开更多
基金supported by a grant from Ministry of Science and Technology China,No.2022ZD0204704(to WW)the National Natural Science Foundation of China,No.82301572(to XZ)the China Postdoctoral Science Foundation,No.2023M731202(to XZ)。
文摘Nonhuman primates are increasingly being used as animal models in neuroscience research.However,efficient neuronal tracing techniques for labeling motor neurons and primary sensory afferents in the monkey spinal cord are lacking.Here,by injecting the cholera toxin B subunit into the sciatic nerve of a rhesus monkey,we successfully labeled the motor neurons and primary sensory afferents in the lumbar and sacralspinal cord.Labeled alpha motor neurons were located in lamina IX of the L6–S1 segments,which innervate both flexors and extensors.The labeled primary sensory afferents were mainly myelinated Aβfibers that terminated mostly in laminae I and II of the L4–L7 segments.Together with the labeled proprioceptive afferents,the primary sensory afferents formed excitatory synapses with multiple types of spinal neurons.In summary,our methods successfully traced neuronal connections in the monkey spinal cord and can be used in spinal cord studies when nonhuman primates are used.
文摘The safety of safe crop products （SCP） is critical to maintain people＇s health and living standard. With the global efforts on the improvement of the traceability of food products, it is inevitable to establish corresponding traceability systems to monitor the safety of crop products in China. In this article, the supply chain pattern of SCP in China has been analyzed and its spatial characters have been described in detail. The study deals with on how to relate traceability technology with GIS, and on how to trace and retrace the safety of SCP using the function of excellent spatial representation, spatial locating, and spatial analysis provided in GIS, which has been discussed from several aspects, such as coding technique of traceability information, transferring technique of traceability information, spatialization of traceability information, and application integration of traceability system. A pilot study was carried out to present the basic functions of the system, which provided an efficient and credible way to trace and retrace the safety of SCP in a real supply chain. An innovative idea has been brought forward for how to establish an efficient, credible, applied traceability system of SCP.
基金supported by National Natural Science Foundation of China(Nos.62266054 and 62166050)Key Program of Fundamental Research Project of Yunnan Science and Technology Plan(No.202201AS070021)+2 种基金Yunnan Fundamental Research Projects(No.202401AT070122)Yunnan International Joint Research and Development Center of China-Laos-Thailand Educational Digitalization(No.202203AP140006)Scientific Research Foundation of Yunnan Provincial Department of Education(No.2024Y159).
文摘In the field of intelligent education,the integration of artificial intelligence,especially deep learning technologies,has garnered significant attention.Knowledge tracing(KT)plays a pivotal role in this field by predicting students’future performance through the analysis of historical interaction data,thereby assisting educators in evaluating knowledgemastery and tailoring instructional strategies.Traditional knowledge tracingmethods,largely based on Recurrent Neural Networks(RNNs)and Transformer models,primarily focus on capturing long-term interaction patterns in sequential data.However,these models may neglect crucial short-term dynamics and other relevant features.This paper introduces a novel approach to knowledge tracing by leveraging a pure Multilayer Perceptron(MLP)architecture.We proposeMixerKT,a knowledge tracing model based on theHyperMixer framework,which uniquely integrates global and localMixer feature extractors.This architecture enables more effective extraction of both long-terminteraction trends and recent learning behaviors,addressing limitations in currentmodels thatmay overlook these key aspects.Empirical evaluations on twowidely-used datasets,ASSIS Tments2009 and Algebra2005,demonstrate that MixerKT consistently outperforms several state-of-the-art models,including DKT,SAKT,and Separated Self-Attentive Neural Knowledge Tracing(SAINT).Specifically,MixerKT achieves higher prediction accuracy,highlighting its effectiveness in capturing the nuances of learners’knowledge states.These results indicate that our model provides a more comprehensive representation of student learning patterns,enhancing the ability to predict future performance with greater precision.
基金the National Natural Science Foundation of China(No.12174229 and 22375117)Natural Science Foundation of Shandong Province(No.ZR2022YQ02 and ZR2023MB149)Taishan Scholars Program of Shandong Province(No.tsqn202306152)for financial support.
文摘Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics.
文摘This work focused on determining the physico-chemical characteristics (pH, carbon and nitrogen) and trace metal elements (TMEs) content (As, Sb, Cd, Hg, Ni, Pb, Cr, Zn) of soils in the Brazzaville city. Soil samples were taken from a depth of 0 to 20 cm using a hand auger on both banks of five tributaries of the Congo River (Djoué, Mfilou, Mfoa, Tsiémé, Djiri) that flow through the city of Brazzaville. 90 sampling points were defined, with 3 points 250 m apart on the banks and located, for each river, at three sites: upstream, midstream and downstream. Finally, 15 composite samples representative of the study area were taken. The average pH values of the water varied between 6.5 and 7.5. These pH values show that the soils studied are neutral. Total carbon content varied between 0.7% (Djiri) and 1.6% (Djoué). Total nitrogen content ranged from 0.08% (Djiri) to 0.12% (Djoué). TMEs contents varied from 0.5 to 1.8 mg/kg for Sb, from 0.5 to 2.5 mg/kg for As, from 0.1 to 0.18 mg/kg for Cd, from 4.2 to 11.3 mg/kg for Cr, from 0.07 to 0.27 mg/kg for Hg, from 0.7 to 2.4 mg/kg for Ni, from 0 to 158 mg/kg for Pb and from 16 to 105 mg/kg for Zn. The lowest TMEs levels were observed in the soils of the Djiri river, while the highest levels were observed in the soils of the Djoué and Tsiémé rivers. The ANOVA and Bonferroni test did not show significant differences in the means of the parameters measured (p > 0.05). The TMEs levels were below the accepted standards (NF U44-041), with the exception of Pb, which had high levels downstream of the Djoué. According to the pollution index values calculated using soil TME content, the soils on the banks of the Djoué river are considered polluted, while those on the banks of the Tsiémé river are moderately polluted, those on the banks of the Mfoa and Mfilou rivers are slightly polluted, and the soils on the banks of Djiri river are unpolluted.
基金supported by the National Natural Science Foundation of China(52376103,542B2081).
文摘The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.
文摘Introduction: During pregnancy, the increased demand for all the nutrients required for the development of the foetus means that the maternal stock of trace elements and minerals may become unbalanced if dietary intake fails to compensate. The aim of this research is to determine the status of trace elements (calcium, copper, magnesium, selenium and zinc) in pregnant women in the city of Kisangani. Methods: We carried out an analytical cross-sectional study of non-pregnant and pregnant women living in Kisangani, from 05 October 2023 to 05 January 2024. Concentrations of trace elements in sera were analysed using an inductively coupled plasma mass spectrophotometer (ICP-MS Agilent 7700X). Statistical analysis of the data was performed using R software version 4.3.0. Results: The mean age was 26.3 ± 6.7 years;the mean copper and magnesium levels in the serum of pregnant women were 12.58 ± 1.13 micromol/l and 1.03 ± 1.03 mmol/l respectively. The medians for calcium and zinc were 1.49 mmol/l and 8.42 micromol/l. The selenium mode was 0.41 micromol/l. Variations in trace element levels in sera of pregnant women were 0.94 - 2.22 mmol/l for calcium;0.31 - 0.78 micromol/l for selenium;and 7.29 - 12.72 micromol/l for zinc;11.04 - 14.99 micromol/l for copper, and 0.082 - 1.05 mmol/l for magnesium. Conclusion: Serum trace element concentrations in pregnant women were lower than those observed in non-pregnant women. Trace element reserves in pregnant women depended on their nutrient status prior to pregnancy, hence, there was an urgent need for trace element balance prior to pregnancy.
基金C.Lana and F.F.Alkmim benefit from the Brazilian National Research Council(CNPq)research grants 3073353/2019-2 and 311543/2020-0.C.Lana,F.F.Alkmim,and Maria Eugênia Souza are part of the Instituto GeoAtlântico,a National Institute of Science and Technology,CNPq-Brazil process 405653/2022-0We acknowledge Petrobras’s support during the investigation and permission to publish this study.I.Figueiredo acknowledged the Brazilian Federal Agency for Support and Evaluation of Graduate Education(CAPES)for Master's scholarship 88887.816343/2023-00.
文摘The opening of the Central South Atlantic and the consequent formation of the eastern Brazilian continental margin was marked by a complex history of mafic magmatism,carbonate sedimentation,and deposition of a thick salt layer.The carbonates underlying the salt layer(pre-salt carbonates)were formed in restricted lacustrine basins.Here,the timing and fluid sources of deposition,diagenetic,and hydrothermal alterations of the pre-salt carbonate rocks are defined through in-situ U-Pb dating,87Sr/86Sr,and trace element analyses of samples from the Santos Basin.The very alkaline nature of the Aptian lake(s)produced characteristically unique and widely distributed carbonate rocks such as Mg-clays with calcite spherulite and calcite crystal shrub limestones transitioning laterally and vertically into travertines formed by hydrothermal pulses during basin evolution.Hydrothermalism caused extensive replacement,dissolution,and calcite cementation.REE+Y PAAS-normalised patterns and 87Sr/86Sr ratios indicate that deposition/eo-diagenesis of the primary carbonates occurred in a lacustrine environment primarily controlled by evaporation,pH,and continental water source,with 2%–10%hydrothermal fluid input.Trace elements and Sr-isotope of travertines and burial diagenetic phases show that they are produced from a hot mixture of mafic/mantle-derived fluids and dissolution/alteration of older carbonate formations.U-Pb dating indicates that carbonate deposition occurred between 124.8±2.6 Ma and 120.0±1.6 Ma,earlier than previously proposed,followed closely by the circulation of hydrothermal fluids.Replacement and cementation ages range from 120.5±2.4 Ma to 80.4±2.4 Ma.
文摘This review systematically summarizes the core advances in the field of trace elements and tumors,and clarifies the dual roles of key elements such as Zn,Cu,Fe,Se,Mn,and Ni in tumorigenesis(e.g.,DNA damage repair),tumor progression(e.g.,tumor microenvironment regulation),and therapeutic response-these elements not only possess tumor-suppressive potential but can also contribute to tumorigenesis.Meanwhile,it confirms the breakthrough value of multi-omics technologies and organoid models in deciphering the“element-cell-tumor”interaction mechanisms,which overcomes the limitations of traditional in vitro experiments and also points out the core directions for subsequent clinical research.
基金supported by grants from the Human Resources Development program (Grant No.20204010600250)the Training Program of CCUS for the Green Growth (Grant No.20214000000500)by the Korea Institute of Energy Technology Evaluation and Planning (KETEP)funded by the Ministry of Trade,Industry,and Energy of the Korean Government (MOTIE).
文摘It is of great importance to obtain precise trace data,as traces are frequently the sole visible and measurable parameter in most outcrops.The manual recognition and detection of traces on high-resolution three-dimensional(3D)models are relatively straightforward but time-consuming.One potential solution to enhance this process is to use machine learning algorithms to detect the 3D traces.In this study,a unique pixel-wise texture mapper algorithm generates a dense point cloud representation of an outcrop with the precise resolution of the original textured 3D model.A virtual digital image rendering was then employed to capture virtual images of selected regions.This technique helps to overcome limitations caused by the surface morphology of the rock mass,such as restricted access,lighting conditions,and shading effects.After AI-powered trace detection on two-dimensional(2D)images,a 3D data structuring technique was applied to the selected trace pixels.In the 3D data structuring,the trace data were structured through 2D thinning,3D reprojection,clustering,segmentation,and segment linking.Finally,the linked segments were exported as 3D polylines,with each polyline in the output corresponding to a trace.The efficacy of the proposed method was assessed using a 3D model of a real-world case study,which was used to compare the results of artificial intelligence(AI)-aided and human intelligence trace detection.Rosette diagrams,which visualize the distribution of trace orientations,confirmed the high similarity between the automatically and manually generated trace maps.In conclusion,the proposed semi-automatic method was easy to use,fast,and accurate in detecting the dominant jointing system of the rock mass.
基金supported by the National Natural Science Foundation of China (No.U19A2063)the Jilin Provincial Science&Technology Development Program of China (No.20230201080GX)。
文摘Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.
基金supported by the National Natural Science Foundation of China(No.42222205)the National Key Research and Development Program of China(No.2017YFC0602403)the Fundamental Research Funds for the Central Universities,CHD(No.300102273301)。
文摘Quartz trace elements are extensively employed in studying magmatic evolution,fluid evolution,and metal enrichment.The Bianjiadayuan Ag-Pb-Zn-Sn deposit is a typical magmatichydrothermal system in northeastern China,however,studies on its complex magmatic-hydrothermal evolution are limited.This study investigates the quartz from the Bianjiadayuan deposit to gain insight into the physicochemical evolution of mineralization using cathodoluminescence(CL)textures and laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)of quartz.Five types quartz(Q1 to Q5)were identified.From Q1 in quartz porphyry to Q5 in Ag-Pb-Zn veins,the CL intensity and Ti content gradually decreases,and Ge,Ge/Ti,and Al/Ti ratios increase,indicating a temperature decline from magmatic to hydrothermal stages.The Sb content shows an opposite trend to Ti content,correlating positively with Ge content in quartz,suggesting that Sb content could also be temperature-dependent.These trace elements in quartz indicate cooling is critical for Ag mineralization.Furthermore,quartz phenocryst(Q1)from the quartz porphyry shows low Al/Ti(mostly<4)and Ge/Ti ratios(<0.04),suggesting a low degree of magmatic evolution.The Sb content in Q5 from Ag-Pb-Zn-quartz veins(>1 ppm,mostly tens of ppm)is notably higher compared to quartz in other lithologies including Sn-bearing quartz veins(<1 ppm),suggesting that Sb contents can serve as an effective indicator of Ag mineralization.
文摘Field-and petrographic investigations,together with microanalytical major-and traceelement studies,were carried out on clinopyroxene and amphibole from high-Mg diorite in the subduction-related Chelyabinsk granitic massif to understand its petrogenesis and source.The clinopyroxene composition(high Mg#,Cr-content,sum of REE and Ti/Eu ratio;depletion in HREE;negative Eu-anomaly)indicates that it formed from a reduced melt derived from a mantle source metasomatized by fluids/melts having crustal affinity.Melt compositions in equilibrium with clinopyroxene and amphibole were calculated using solid/liquid partition coefficients.The high Nb/Y and Zr/Y ratio values of a liquid simulated from clinopyroxene,which appears to have very similar characteristics to sanukitoid melts,indicate a low degree of melting of the mantle source.Melt simulated from amphibole is more evolved and more felsic(dacitic).It displays a geochemical“amphibole fractionation”signature,indicating the peritectic transformation of clinopyroxene to amphibole in the lower crust.Rock textures and major element mineral compositions suggest that further amphibole was precipitated directly from the melt in the middle crust.The results show that the Chelyabinsk highMg diorite was probably formed as a cumulate from sanukitoid-like melt during its ascent and cooling below dacitic liquidus inside the amphibole stability field.
基金funded by National Natural Science Foundation of China(No.41706074)Natural Science Foundation of Shandong Province(No.ZR2022 MD114)Geological Environment Investigation and Monitoring of the Coastal Zone in the Yangtze River Estuary(No.DD20242714).
文摘We investigated the concentrations,vertical distribution,and enrichment status of ten trace metal elements(Cr,Hg,Cu,Pb,Zn,Cd,As,Co,V,and Ni)in sediments of core D04 from the muddy area outside the Oujiang River Estuary.In addition to V,As,and Hg,the concentrations of Cr,Cu,Zn,Pb,Cd,Ni and Co were constrained by sediment grain size and organic matter.Al-though the concentrations of trace metals fluctuated during the 5.8–2.5 kyr BP period,overall variations remained relatively stable.However,during the 2.5–0 kyr BP period,the concentrations of Cd,Zn,Cu,Pb,Ni,Ni,and Cr showed an increasing trend within the fluctuations,ultimately reaching relatively high levels.The muddy area was lightly contaminated by heavy metals such as As,Hg,and Cu.The concentrations of Hg,As,and Cu have been continuously increasing since 2.5 kyr BP,indicating clear impacts from fre-quent human activities.
基金supported by National Natural Science Foundation of China(52372249 and 52102329)the support from the Program of Shanghai Academic Research Leader(21XD1424400)。
文摘Polyethylene oxide(PEO)-based solid-state polymer electrolytes(SPE)face the challenges of insufficient ionic conductivity and uncontrollable Li dendrite growth.The filler strategy can reinforce anode interface stability,but at the cost of a large filler content(usually more than 10 wt%).This would increase the granular sensation,gravitational separation risk,and electrolyte membrane roughness with the creation of inhomogeneous Li^(+)transport channels between filler and polymer.Herein,we propose a trace filling strategy to address the above problems by introducing an amphoteric molecule L-Cysteine(LCy)as an eco-friendly and low-cost electrolyte additive.Only trace amount of LCy is required and integrated into PEO to form a homogenous,granule-less SPE with enhanced ionic conductivity and dendrite suppression capability.The ionic conductivity increases to 0.54 mS cm^(-1)at 60℃ after introducing only 1 wt%LCy.The amphotericity of LCy with basic–NH_(2)and acidic–COOH groups can promote the dissociation of Li salt and release more free Li ions through Lewis acid-base synergy,as well as the formation of multiple hydrogen bonds between PEO and LCy.The trace LCy additive swiftly leads to the formation of more ionic conductive interphases at both the anode and cathode sides.The composite SPE enables the stable cycling of Li metal for over 1400 h at 0.2 mA cm^(-2)and sustains a maximum current density up to 1.4 mA cm^(-2)in Li Li symmetric cells.The corresponding all-solid-state Li||FeF_(3)full cells exhibit a high specific capacity up to 567 mA h g^(-1)at 0.2 C and stable cycling performance for at least 700 cycles at 0.5 C with a high capacity retention.The excellent interface compatibility also guarantees the achievement of highcapacity Li-Fe-F conversion reaction even under the thin electrolyte membrane thickness and largerscale pouch cell configuration.
基金supported by the National Natural Science Foundation of China(No.52300005)China Postdoctoral Science Foundation(No.2023TQ0098)+5 种基金Heilongjiang Postdoctoral Fund(No.LBH-Z23175)Heilongjiang Touyan Innovation Team Program(No.HIT-SE-01)the Crossover Fund of Medical Engineering Science of Harbin Institute of Technology(No.IR2021107)the National Natural Science Foundation of International(Regional)Cooperation and Exchange Project(No.51961125104)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS15)the Ecological and Environmental Protection Research Project of Heilongjiang Province(No.HST2022ST006).
文摘Halogenated aromatic disinfection byproducts(DBPs)are gradually receiving attention due to their high detection frequency and usually higher toxicity than regulated DBPs.In this study,we established a solid phase extraction(SPE)-LC-MS/MS method to simultaneously trace analyze 59 halogenated aromatic DBPs.The limits of detection and limits of quantification of halogenated aromatic DBPs ranged from 0.03 to 135.23 ng/L and from 0.1 to 450.76 ng/L,respectively.The range of recoveries and relative standard deviation(RSD)in river water were between 72.41%to 119.54%and 1.86%to 16.03%,respectively.Therefore,this method can be used to accurately analyze trace levels of halogenated aromatic DBPs in drinking water.The occurrence and transformation of halogenated aromatic DBPs were explored based on this method.In the chlorinated simulated source water and chlorinated river water,20 and 45 halogenated aromatic DBPs were determined,respectively.The active halogen species(HOCl,HOBr,and HOI)first reacted with natural organic matter(NOM)to form halogenated aromatic DBPs.Then,chlorine further reacted with the halogenated aromatic DBPs to convert them into small-molecule halogenated aliphatic DBPs through oxidation,electrophilic substitution,and hydrolysis reaction,etc.In the chlorinated simulated source water,chlorinated river water,and tap water,the toxicity contribution of bromoacetic acids(Br-HAAs)accounted for themajority(>71.16%).Given that halogenated aromatic DBPs are intermediate products of halogenated aliphatic DBPs,controlling the formation of halogenated aromatic DBPs is beneficial in decreasing the formation of halogenated aliphatic DBPs,thereby diminishing the toxicity of drinking water.
文摘With the rapid advancement of medical artificial intelligence(AI)technology,particularly the widespread adoption of AI diagnostic systems,ethical challenges in medical decision-making have garnered increasing attention.This paper analyzes the limitations of algorithmic ethics in medical decision-making and explores accountability mechanisms,aiming to provide theoretical support for ethically informed medical practices.The study highlights how the opacity of AI algorithms complicates the definition of decision-making responsibility,undermines doctor-patient trust,and affects informed consent.By thoroughly investigating issues such as the algorithmic“black box”problem and data privacy protection,we develop accountability assessment models to address ethical concerns related to medical resource allocation.Furthermore,this research examines the effective implementation of AI diagnostic systems through case studies of both successful and unsuccessful applications,extracting lessons on accountability mechanisms and response strategies.Finally,we emphasize that establishing a transparent accountability framework is crucial for enhancing the ethical standards of medical AI systems and protecting patients’rights and interests.
基金supported by the Korea Polar Research Institute grant(PE25100)the National Research Foundation of Korea grant funded by the Korean Government(NRF2022R1A2C3007047)supported by Korea Institute of Marine Science&Technology Promotion(KIMST)and by the Ministry of Oceans and Fisheries(RS-2023-00256677,PM23020).
文摘The measurement of trace elements in Antarctic snow is crucial for understanding historical atmospheric geochemical changes and circulation patterns.However,studies on their spatial distributions remain limited,particularly those evaluating multiple metals across several snowpits,making interpretation challenging.This study investigates the distributions and sources of trace elements-including Cd,Ba,Pb,U,Bi,V,Mn,Fe,Cu,Zn,and As-across four snowpits in the Lambert Glacier Basin,East Antarctica.The trace elements exhibit site-,element-,and season-dependent variations,with higher concentrations observed at inland sites.In contrast,δ^(18)O and ion concentrations decrease with increasing distance from the coast and elevation,underscoring the influence of marine emissions.Crustal sources primarily contributed to Ba,U,V,Mn,and Fe,while non-crustal sources predominantly contributed to Cd,Bi,Zn,Pb,Cu,and As.Positive matrix factorization(PMF)analysis indicates that trace element concentrations in Pits 2 and 3 are influenced by both crustal and non-crustal sources,while Pit 4 reflects a mixed-source influence.Pit 1(coastal site)also indicates the mixed sources with influence of a highly dynamic marine climate and environment.The PMF results reveal similarities in emission sources and atmospheric transport patterns across the snowpits,facilitating a more comprehensive interpretation of longer ice core records.Overall,this study provides valuable insights into trace element distributions and enhances our understanding of past environmental and climatic conditions.
