Designing efficient and long-lasting non-metal electrocatalysts is an urgent task for addressing the issue of kinetic hysteresis in electrochemical oxidation reactions.The bimetallic hydroxides,catalyzing the oxygen e...Designing efficient and long-lasting non-metal electrocatalysts is an urgent task for addressing the issue of kinetic hysteresis in electrochemical oxidation reactions.The bimetallic hydroxides,catalyzing the oxygen evolution reaction(OER),have significant research potential because hydroxide reconstruction to generate an active phase is a remarkable advantage.Herein,the complete reconstruction of ultrathin CoNi(OH)_(2) nanosheets was achieved by embedding Ag nanoparticles into the hydroxide to induce a spontaneous redox reaction(SRR),forming heterojunction Ag@CoNi(OH)_(2) for bifunctional hydrolysis.Theoretical calculations and in situ Raman and ex situ characterizations revealed that the inductive effect of the Ag cation redistributed the charge to promote phase transformation to highly activate Ag-modified hydroxides.The Co-Ni dual sites in Co/NiOOH serve as novel active sites for optimizing the intermediates,thereby weakening the barrier formed by OOH^*.Ag@CoNi(OH)_(2) required a potential of 1.55 V to drive water splitting at a current density of 10 mA cm^(-2),with nearly 98.6% Faraday efficiency.Through ion induction and triggering of electron regulation in the OER via the synergistic action of the heterogeneous interface and surface reconstruction,this strategic design can overcome the limited capacity of bimetallic hydroxides and bridge the gap between the basic theory and industrialization of water decomposition.展开更多
Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless planets.However,current research on space weathering focuses mainly on the Moon and certain...Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless planets.However,current research on space weathering focuses mainly on the Moon and certain types of asteroids.In particular,the impacts of meteoroids and micrometeoroids,radiation from solar wind/solar flares/cosmic rays,and thermal fatigue due to temperature variations are being studied.Space weathering produces various transformation products such as melted glass,amorphous layers,iron particles,vesicles,and solar wind water.These in turn lead to soil maturation,changes in visible and near-infrared reflectance spectra(weakening of characteristic absorption peaks,decreased reflectance,increased near-infrared slope),and alterations in magnetism(related to small iron particles),collectively termed the“lunar model”of space weathering transformation.Compared to the Moon and asteroids,Mercury has unique spatial environmental characteristics,including more intense meteoroid impacts and solar thermal radiation,as well as a weaker particle radiation environment due to the global distribution of its magnetic field.Therefore,the lunar model of space weathering may not apply to Mercury.Previous studies have extensively explored the eff ects of micrometeoroid impacts.Hence,this work focuses on the eff ects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar irradiation.Through the utilization of highvalence state,heavy ion implantation,and vacuum heating simulation experiments,this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite,pyroxene,and olivine on Mercury’s surface and compares them to the weathering transformation model of the Moon.The experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe^(0)directly but can facilitate its formation,while prolonged exposure to solar thermal radiation on Mercury’s surface can lead directly to the formation of np-Fe^(0).Therefore,intense solar thermal radiation is a crucial component of the unique space weathering transformation process on Mercury’s surface.展开更多
Oral squamous cell carcinoma (OSCC) is the predominant type of oral cancer, while some patients may develop oral multiple primary cancers (MPCs) with unclear etiology. This study aimed to investigate the clinicopathol...Oral squamous cell carcinoma (OSCC) is the predominant type of oral cancer, while some patients may develop oral multiple primary cancers (MPCs) with unclear etiology. This study aimed to investigate the clinicopathological characteristics and genomic alterations of oral MPCs. Clinicopathological data from patients with oral single primary carcinoma (SPC, n=202) and oral MPCs (n=34) were collected and compared. Copy number alteration (CNA) analysis was conducted to identify chromosomal-instability differences among oral MPCs, recurrent OSCC cases, and OSCC patients with lymph node metastasis. Whole-exome sequencing was employed to identify potential unique gene mutations in oral MPCs patients. Additionally, CNA and phylogenetic tree analyses were used to gain preliminary insights into the molecular characteristics of different primary tumors within individual patients. Our findings revealed that, in contrast to oral SPC, females predominated the oral MPCs (70.59%), while smoking and alcohol use were not frequent in MPCs.Moreover, long-term survival outcomes were poorer in oral MPCs. From a CNA perspective, no significant differences were observed between oral MPCs patients and those with recurrence and lymph node metastasis. In addition to commonly mutated genes such as CASP8, TP53 and MUC16, in oral MPCs we also detected relatively rare mutations, such as HS3ST6 and RFPL4A. Furthermore, this study also demonstrated that most MPCs patients exhibited similarities in certain genomic regions within individuals, and distinct differences of the similarity degree were observed between synchronous and metachronous oral MPCs.展开更多
Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a ...Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is detected.Considering that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris.展开更多
To date,several molecules have been found to facilitate iron influx,while the types of iron influx channels remain to be elucidated.Here,Piezo1 channel was identified as a key iron transporter in response to mechanica...To date,several molecules have been found to facilitate iron influx,while the types of iron influx channels remain to be elucidated.Here,Piezo1 channel was identified as a key iron transporter in response to mechanical stress.Piezo1-mediated iron overload disturbed iron metabolism and exaggerated ferroptosis in nucleus pulposus cells(NPCs).Importantly,Piezo1-induced iron influx was independent of the transferrin receptor(TFRC),a well-recognized iron gatekeeper.Furthermore,pharmacological inactivation of Piezo1 profoundly reduced iron accumulation,alleviated mitochondrial ROS,and suppressed ferroptotic alterations in stimulation of mechanical stress.Moreover,conditional knockout of Piezo1(Col2a1-CreERT Piezo1^(flox/flox))attenuated the mechanical injury-induced intervertebral disc degeneration(IVDD).Notably,the protective effect of Piezo1 deficiency in IVDD was dampened in Piezo1/Gpx4 conditional double knockout(cDKO)mice(Col2a1-CreERT Piezo1^(flox/flox)/Gpx4^(flox/flox)).These findings suggest that Piezo1 is a potential determinant of iron influx,indicating that the Piezo1-iron-ferroptosis axis might shed light on the treatment of mechanical stress-induced diseases.展开更多
Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored therein.Reported here is t...Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored therein.Reported here is the evolution of rock failure with diferent master crack types as investigated using Brazilian splitting tests(BSTs),direct shear tests(DSTs),and uniaxial compression tests(UCTs).The AE parameters and typical modes of each fracture type were obtained,and the energy release characteristics of each fracture mechanism were discussed.From the observed changes in the AE parameters,the rock fracture process exhibits characteristics of staged intensifcation.The scale and energy level of crack activity in the BSTs were signifcantly lower than those in the DSTs and UCTs.The proportion of tensile cracks in the BSTs was 65%–75%,while the proportions of shear cracks in the DSTs and UCTs were 75%–85%and 70%–75%,respectively.During the rock loading process under diferent conditions,failure was accompanied by an increased number of shear cracks.The amplitude,duration,and rise time of the AE signal from rock failure were larger when the failure was dominated by shear cracks rather than tensile ones,and most of the medium-and high-energy signals had medium to low frequencies.After calculating the proposed energy amplitude ratio,the energy release of shear cracks was found to exceed that of tensile cracks at the same fracture scale.展开更多
Background Genomic selection involves choosing as parents those elite individuals with the higher genomic estimated breeding values(GEBV)to accelerate the speed of genetic improvement in domestic animals.But after mul...Background Genomic selection involves choosing as parents those elite individuals with the higher genomic estimated breeding values(GEBV)to accelerate the speed of genetic improvement in domestic animals.But after multi-generation selection,the rate of inbreeding and the occurrence of homozygous harmful alleles might increase,which would reduce performance and genetic diversity.To mitigate the above problems,we can utilize genomic mating(GM)based upon optimal mate allocation to construct the best genotypic combinations in the next generation.In this study,we used stochastic simulation to investigate the impact of various factors on the efficiencies of GM to optimize pairing combinations after genomic selection of candidates in a pig population.These factors included:the algorithm used to derive inbreeding coefficients;the trait heritability(0.1,0.3 or 0.5);the kind of GM scheme(focused average GEBV or inbreeding);the approach for computing the genomic relationship matrix(by SNP or runs of homozygosity(ROH)).The outcomes were compared to three traditional mating schemes(random,positive assortative or negative assortative matings).In addition,the performance of the GM approach was tested on real datasets obtained from a Large White pig breeding population.Results Genomic mating outperforms other approaches in limiting the inbreeding accumulation for the same expected genetic gain.The use of ROH-based genealogical relatedness in GM achieved faster genetic gains than using relatedness based on individual SNPs.The GROH-based GM schemes with the maximum genetic gain resulted in 0.9%-2.6%higher rates of genetic gainΔG,and 13%-83.3%lowerΔF than positive assortative mating regardless of heritability.The rates of inbreeding were always the fastest with positive assortative mating.Results from a purebred Large White pig population,confirmed that GM with ROH-based GRM was more efficient than traditional mating schemes.Conclusion Compared with traditional mating schemes,genomic mating can not only achieve sustainable genetic progress but also effectively control the rates of inbreeding accumulation in the population.Our findings demonstrated that breeders should consider using genomic mating for genetic improvement of pigs.展开更多
Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of bu...Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata.展开更多
Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape va...Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape varieties with different lengths of small inflorescences,namely‘Musct Hambourg’grape(Vitis vinifera),‘Concord’grape(Vitis labrusca),‘ShanPuTao’grape(Vitis amurensis)and‘GongNiang2Hao’grape(Vitis amurensis×Vitis vinifera)were used as test materials.Four varieties ovary were significant differences by means of stereomicroscope,paraffin section.The expression of ovary determining gene VvAGAMOUS(VvAG)and its development related genes VvCRABS CLAW(VvCRC)and VvAGAMOUS-LIKE 11(VvAGL11)with similar functions during the development of different grape varieties were preliminarily explored using fluorescence quantitative test.The relationship between VvAG and VvCRC,VvAG and VvAGL11 were analyzed using Y1H assay.Our results showed that there were obvious abdominal sutures on the surface of expect for‘Musct Hambourg’grape,and existing poly carpels.The ovary development of‘ShanPuTao’and‘GongNiang2Hao’grape was completed when the inflorescence length was less than 1 cm,while the‘Concord’and‘Musct Hambourg’grape were fully developed when the length of inflorescence was 3–4 and 4–5 cm,respectively.VvAG and VvCRC began to express in large quantities after the formation of stamen primordia,while VvAGL11 during the forming of ovule primordia.Therefore,VvAG and VvCRC mainly regulated the development of stamens and carpels and also promote the development of ovules,while VvAGL11 major regulated the development of ovules.The promoters of VvCRC and VvAGL11 were bound by VvAG.This study provides an important theoretical basis for further research on the molecular mechanism of grape ovary development.展开更多
The oral microbiota is a vital part of the human microbiota that functions in various physiological processes and ishighly relevant to cancers and other diseases. With the alterations of host immune competence, the ho...The oral microbiota is a vital part of the human microbiota that functions in various physiological processes and ishighly relevant to cancers and other diseases. With the alterations of host immune competence, the homeostatic balanceexisting between the oral microbiota and host may be disturbed and result in the development of diseases. Numerousobservations have suggested that small RNAs are key regulators of bacterial pathogenesis and bacteria-host interactions.Further, bacterial small RNAs are considered to be promising biomarkers for the development of novel, and efficacioustherapies for oral dysbiosis. Mechanistic insights into how oral pathogens communicate with other bacteria or host cellsin oral cancers via small RNAs are hot topics of research. Current studies also have begun to elucidate the key role oforal microbiota in the development of systemic diseases. This article discusses existing findings and nascent mechanismsgoverning the small RNA-based interactions between oral microbiota and associated diseases. The knowledge of suchinteractions is key in planning approaches to reverse dysbiosis to achieve health.展开更多
Non-Abelian anyons are exotic quasiparticle excitations hosted by certain topological phases of matter.They break the fermion-boson dichotomy and obey non-Abelian braiding statistics:their interchanges yield unitary o...Non-Abelian anyons are exotic quasiparticle excitations hosted by certain topological phases of matter.They break the fermion-boson dichotomy and obey non-Abelian braiding statistics:their interchanges yield unitary operations,rather than merely a phase factor,in a space spanned by topologically degenerate wavefunctions.They are the building blocks of topological quantum computing.However,experimental observation of non-Abelian anyons and their characterizing braiding statistics is notoriously challenging and has remained elusive hitherto,in spite of various theoretical proposals.Here,we report an experimental quantum digital simulation of projective non-Abelian anyons and their braiding statistics with up to 68 programmable superconducting qubits arranged on a two-dimensional lattice.By implementing the ground states of the toric-code model with twists through quantum circuits,we demonstrate that twists exchange electric and magnetic charges and behave as a particular type of non-Abelian anyons,i.e.,the Ising anyons.In particular,we show experimentally that these twists follow the fusion rules and non-Abelian braiding statistics of the Ising type,and can be explored to encode topological logical qubits.Furthermore,we demonstrate how to implement both single-and two-qubit logic gates through applying a sequence of elementary Pauli gates on the underlying physical qubits.Our results demonstrate a versatile quantum digital approach for simulating non-Abelian anyons,offering a new lens into the study of such peculiar quasiparticles.展开更多
Radix Astragali has been an important traditional Chinese herbal medicine for over 2000 years. It is derived from two plant species, namely, Astragalus mongholicus [Astragalus membranaceus (Fisch.) Bge. var. mongholic...Radix Astragali has been an important traditional Chinese herbal medicine for over 2000 years. It is derived from two plant species, namely, Astragalus mongholicus [Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao] and Astragalus membranaceus [Astragalus membranaceus (Fisch.) Bge.] (Leguminosae ), according to the Pharmacopoeia of the People’s Republic of China. In this study, the genetic diversity and genetic relationships of Radix Astragali in China were analyzed by Inter-Simple Sequence Repeat (ISSR) markers. A total of 25 highly polymorphic ISSR primers were selected to amplify 95 Radix Astragali samples. Among 273 DNA bands amplified, 213 are polymorphic (percentage of polymorphic bands: 78%). The average value of the amplified bands was 10.9 for each primer, and the number varied from 4 to 20. The genetic diversity of the 95 Radix Astragali samples was analyzed by using POPGENE 1.32 software. The Nei’s genetic diversity index (h) and Shannon’s information index (I ) were 0.3590 and 0.5308, respectively, which indicated the abundant genetic diversity of Radix Astragali . The level of genetic diversity in A. membranaceus (h: 0.3109, I : 0.4657) was slightly lower than that in A. mongholicus (h: 0.3364, I : 0.4969). Considering the average genetic similarity coefficient by NTSYS analysis to cluster the A. membranaceus of nine habitats and A. mongholicus of five habitats, Radix Astragali samples were clustered into two groups according to place of origin. This clustering is different from traditional clustering, which divides groups according to species. Results obtained from this study will provide a theoretical basis for the molecular study on germplasm resources of Radix Astragali .展开更多
燃料电池可以直接将化学能转化为电能,是一种极具前景的能量转换设备.目前,铂碳是燃料电池阴极氧还原反应(ORR)常用催化剂,但是铂储量低、价格昂贵、稳定性差且容易受CO毒化,极大地限制了其在燃料电池商业化中的应用.因此,探索价格低廉...燃料电池可以直接将化学能转化为电能,是一种极具前景的能量转换设备.目前,铂碳是燃料电池阴极氧还原反应(ORR)常用催化剂,但是铂储量低、价格昂贵、稳定性差且容易受CO毒化,极大地限制了其在燃料电池商业化中的应用.因此,探索价格低廉、性能优越的非贵金属氧还原催化剂显得尤为重要.大量研究发现,碳基材料具有优越的氧还原性能和良好的电化学稳定性.同时,自然界的生物质种类丰富,是很好的碳基材料来源.本文选取日常生活中最常见的富碳生物质废纸作为碳源,二氰二胺和乙酰丙酮钴分别作为氮源和钴源,经过特定气氛下的梯度升温制得非贵金属钴、氮共掺杂碳纳米管负载多孔碳氧还原催化剂(Co/N/CNT@PC-800).考察了杂原子N掺杂、过渡金属Co掺杂对材料形貌和性能的影响,采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、拉曼(Raman)光谱、氮气吸附-脱附和X射线光电子能谱(XPS)等表征方法探究了Co/N/CNT@PC-800材料的组成与结构,通过循环伏安法(CV)以及线性扫描伏安法(LSV)等电化学测试探究了其氧还原反应性能.SEM和TEM结果表明,Co/N/CNT@PC-800材料为表面生长着大量碳纳米管的多孔碳结构.这是因为二氰二胺和钴引入后,钴催化二氰二胺转化成碳纳米管.金属纳米粒子被封装在碳层之间和碳纳米管中而得到有效的保护,使之不易被酸腐蚀.同时,Co和N元素可以形成更多的活性位点(Co–Nx),增强材料ORR活性.SEM和氮气吸附-脱附结果显示,掺杂Co后,材料的介孔结构会进一步增加,形成微孔/介孔结构.多孔结构可以增强ORR相关物质(O2,H+,OH.,H2O)的传质速率,提升反应速率,达到增强ORR活性的效果.除此之外,多孔的结构也可以促进活性位点的暴露,进而提升材料的ORR性能.XPS结果显示,Co/N/CNT@PC-800材料中N主要以吡啶氮和石墨氮两种形式存在,而这两种类型的氮有利于促进ORR的进行.Raman光谱结果显示,在引入N和Co元素后,材料的缺陷结构有所增加,因而有利于电催化氧还原反应性能的提升.另外,LSV测试结果表明,在引入Co或者N后,材料催化ORR的起始电位、半波电位、极限电流密度均有小幅改善;同时引入Co和N后,Co/N/CNT@PC-800材料催化ORR的起始电位(0.005 V vs.Ag/AgCl)、半波电位(.0.173 V vs.Ag/AgCl)、极限电流密度(.4.117 mA cm.2)均有较大幅度的改善.通过Koutecky-Levich(K-L)方程计算以及旋转环盘电极测得的氧还原极化曲线结果均表明,Co/N/CNT@PC-800材料的氧还原反应是通过准四电子反应转移路径进行.此外,循环(3000圈CV)稳定性测试结果证明,Co/N/CNT@PC-800材料比商业化的Pt/C具有更好的稳定性.总之,本文采用简单的梯度升温法制备出非贵金属钴、氮共掺杂的碳基氧还原催化剂(Co/N/CNT@PC-800),为探索利用生物质制备电催化剂用于燃料电池提供了一种可供选择的途径.展开更多
STSE(Science,Technology,Society and Environment)教育理念注重在情境化教学中促进学生对知识的理解和掌握,强调科学、技术、社会、环境的相互关系,并实现学生对社会发展和进步的进一步认识。本文以“北京冬奥会”这一热点事件为情境...STSE(Science,Technology,Society and Environment)教育理念注重在情境化教学中促进学生对知识的理解和掌握,强调科学、技术、社会、环境的相互关系,并实现学生对社会发展和进步的进一步认识。本文以“北京冬奥会”这一热点事件为情境,基于STSE教育理念,通过将化学与北京冬奥会中社会、技术、环境等元素有机融合,阐述化学如何为北京冬奥会赋能,引导学生对化学产生兴趣,并在潜移默化中提升学生可持续发展的意识,为现代化科技强国建设培养化学类人才。展开更多
基金supported by the Inner Mongolia R&D Program Plan(2021ZD0042,2021EEDSCXSFQZD006)the National Natural Science Foundation of China(21902123)the Natural Science Basic Research Program of Shaanxi(2023-JC-ZD-22)。
文摘Designing efficient and long-lasting non-metal electrocatalysts is an urgent task for addressing the issue of kinetic hysteresis in electrochemical oxidation reactions.The bimetallic hydroxides,catalyzing the oxygen evolution reaction(OER),have significant research potential because hydroxide reconstruction to generate an active phase is a remarkable advantage.Herein,the complete reconstruction of ultrathin CoNi(OH)_(2) nanosheets was achieved by embedding Ag nanoparticles into the hydroxide to induce a spontaneous redox reaction(SRR),forming heterojunction Ag@CoNi(OH)_(2) for bifunctional hydrolysis.Theoretical calculations and in situ Raman and ex situ characterizations revealed that the inductive effect of the Ag cation redistributed the charge to promote phase transformation to highly activate Ag-modified hydroxides.The Co-Ni dual sites in Co/NiOOH serve as novel active sites for optimizing the intermediates,thereby weakening the barrier formed by OOH^*.Ag@CoNi(OH)_(2) required a potential of 1.55 V to drive water splitting at a current density of 10 mA cm^(-2),with nearly 98.6% Faraday efficiency.Through ion induction and triggering of electron regulation in the OER via the synergistic action of the heterogeneous interface and surface reconstruction,this strategic design can overcome the limited capacity of bimetallic hydroxides and bridge the gap between the basic theory and industrialization of water decomposition.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB 41000000)the National Natural Science Foundation of China(42273042 and 41931077)+1 种基金the Youth Innovation Promotion Association,the Chinese Academy of Sciences(2020395)the Guizhou Provincial Science and Technology Projects(QKHJC-ZK[2023]-General 473).
文摘Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless planets.However,current research on space weathering focuses mainly on the Moon and certain types of asteroids.In particular,the impacts of meteoroids and micrometeoroids,radiation from solar wind/solar flares/cosmic rays,and thermal fatigue due to temperature variations are being studied.Space weathering produces various transformation products such as melted glass,amorphous layers,iron particles,vesicles,and solar wind water.These in turn lead to soil maturation,changes in visible and near-infrared reflectance spectra(weakening of characteristic absorption peaks,decreased reflectance,increased near-infrared slope),and alterations in magnetism(related to small iron particles),collectively termed the“lunar model”of space weathering transformation.Compared to the Moon and asteroids,Mercury has unique spatial environmental characteristics,including more intense meteoroid impacts and solar thermal radiation,as well as a weaker particle radiation environment due to the global distribution of its magnetic field.Therefore,the lunar model of space weathering may not apply to Mercury.Previous studies have extensively explored the eff ects of micrometeoroid impacts.Hence,this work focuses on the eff ects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar irradiation.Through the utilization of highvalence state,heavy ion implantation,and vacuum heating simulation experiments,this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite,pyroxene,and olivine on Mercury’s surface and compares them to the weathering transformation model of the Moon.The experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe^(0)directly but can facilitate its formation,while prolonged exposure to solar thermal radiation on Mercury’s surface can lead directly to the formation of np-Fe^(0).Therefore,intense solar thermal radiation is a crucial component of the unique space weathering transformation process on Mercury’s surface.
基金supported by the National Nature Science Foundation of China (China, grant numbers 81671006, 81300894)CAMS Innovation Fund for Medical Sciences (China, grant number 2019-I2M-5-038)National Clinical Key Discipline Construction Project (China, PKUSSNKP-202102)。
文摘Oral squamous cell carcinoma (OSCC) is the predominant type of oral cancer, while some patients may develop oral multiple primary cancers (MPCs) with unclear etiology. This study aimed to investigate the clinicopathological characteristics and genomic alterations of oral MPCs. Clinicopathological data from patients with oral single primary carcinoma (SPC, n=202) and oral MPCs (n=34) were collected and compared. Copy number alteration (CNA) analysis was conducted to identify chromosomal-instability differences among oral MPCs, recurrent OSCC cases, and OSCC patients with lymph node metastasis. Whole-exome sequencing was employed to identify potential unique gene mutations in oral MPCs patients. Additionally, CNA and phylogenetic tree analyses were used to gain preliminary insights into the molecular characteristics of different primary tumors within individual patients. Our findings revealed that, in contrast to oral SPC, females predominated the oral MPCs (70.59%), while smoking and alcohol use were not frequent in MPCs.Moreover, long-term survival outcomes were poorer in oral MPCs. From a CNA perspective, no significant differences were observed between oral MPCs patients and those with recurrence and lymph node metastasis. In addition to commonly mutated genes such as CASP8, TP53 and MUC16, in oral MPCs we also detected relatively rare mutations, such as HS3ST6 and RFPL4A. Furthermore, this study also demonstrated that most MPCs patients exhibited similarities in certain genomic regions within individuals, and distinct differences of the similarity degree were observed between synchronous and metachronous oral MPCs.
基金supported in part by the National Natural Science Foundation of China Nos. 12163006 and 12233006the Basic Research Program of Yunnan Province No. 202201AT070137+1 种基金the joint foundation of Department of Science and Technology of Yunnan Province and Yunnan University No. 202201BF070001-020support by the Xingdian Talent Support Plan-Youth Project。
文摘Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is detected.Considering that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris.
基金supported in part by the National Nature Science Foundation(81874022 and 82172483 to Xinyu Liu,82102522 to Lianlei Wang,82072478 to Yunpeng Zhao,82072435 to Qiang Yang,82073437 to Weiwei Li,81930070 to Shiqing Feng,82272548 to Lei Cheng)Key R&D Project of Shandong Province(2022CXGC010503 to Xinyu Liu)+1 种基金Shandong Natural Science Foundation(ZR202102210113 to Lianlei Wang,ZR2020YQ54 to Yunpeng Zhao)Shandong Province Taishan Scholar Project(tsqn202211317 to Lianlei Wang).The authors thank the Translational Medicine Core Facility of Shandong University for the consultation and instrument availability that supported this work.
文摘To date,several molecules have been found to facilitate iron influx,while the types of iron influx channels remain to be elucidated.Here,Piezo1 channel was identified as a key iron transporter in response to mechanical stress.Piezo1-mediated iron overload disturbed iron metabolism and exaggerated ferroptosis in nucleus pulposus cells(NPCs).Importantly,Piezo1-induced iron influx was independent of the transferrin receptor(TFRC),a well-recognized iron gatekeeper.Furthermore,pharmacological inactivation of Piezo1 profoundly reduced iron accumulation,alleviated mitochondrial ROS,and suppressed ferroptotic alterations in stimulation of mechanical stress.Moreover,conditional knockout of Piezo1(Col2a1-CreERT Piezo1^(flox/flox))attenuated the mechanical injury-induced intervertebral disc degeneration(IVDD).Notably,the protective effect of Piezo1 deficiency in IVDD was dampened in Piezo1/Gpx4 conditional double knockout(cDKO)mice(Col2a1-CreERT Piezo1^(flox/flox)/Gpx4^(flox/flox)).These findings suggest that Piezo1 is a potential determinant of iron influx,indicating that the Piezo1-iron-ferroptosis axis might shed light on the treatment of mechanical stress-induced diseases.
基金Major Program of Shandong Provincial Natural Science Foundation(No.ZR2019ZD13)Major Scientifc and Technological Innovation Project of Shandong Provincial Key Research Development Program(No.2019SDZY02)Project of Taishan Scholar in Shandong Province.
文摘Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored therein.Reported here is the evolution of rock failure with diferent master crack types as investigated using Brazilian splitting tests(BSTs),direct shear tests(DSTs),and uniaxial compression tests(UCTs).The AE parameters and typical modes of each fracture type were obtained,and the energy release characteristics of each fracture mechanism were discussed.From the observed changes in the AE parameters,the rock fracture process exhibits characteristics of staged intensifcation.The scale and energy level of crack activity in the BSTs were signifcantly lower than those in the DSTs and UCTs.The proportion of tensile cracks in the BSTs was 65%–75%,while the proportions of shear cracks in the DSTs and UCTs were 75%–85%and 70%–75%,respectively.During the rock loading process under diferent conditions,failure was accompanied by an increased number of shear cracks.The amplitude,duration,and rise time of the AE signal from rock failure were larger when the failure was dominated by shear cracks rather than tensile ones,and most of the medium-and high-energy signals had medium to low frequencies.After calculating the proposed energy amplitude ratio,the energy release of shear cracks was found to exceed that of tensile cracks at the same fracture scale.
基金funded by the Natural Science Foundations of China(No.32172702)National Key Research and Development Program of China(2021YFD1301101)Agricultural Science and Technology Innovation Program(ASTIP-IAS02)。
文摘Background Genomic selection involves choosing as parents those elite individuals with the higher genomic estimated breeding values(GEBV)to accelerate the speed of genetic improvement in domestic animals.But after multi-generation selection,the rate of inbreeding and the occurrence of homozygous harmful alleles might increase,which would reduce performance and genetic diversity.To mitigate the above problems,we can utilize genomic mating(GM)based upon optimal mate allocation to construct the best genotypic combinations in the next generation.In this study,we used stochastic simulation to investigate the impact of various factors on the efficiencies of GM to optimize pairing combinations after genomic selection of candidates in a pig population.These factors included:the algorithm used to derive inbreeding coefficients;the trait heritability(0.1,0.3 or 0.5);the kind of GM scheme(focused average GEBV or inbreeding);the approach for computing the genomic relationship matrix(by SNP or runs of homozygosity(ROH)).The outcomes were compared to three traditional mating schemes(random,positive assortative or negative assortative matings).In addition,the performance of the GM approach was tested on real datasets obtained from a Large White pig breeding population.Results Genomic mating outperforms other approaches in limiting the inbreeding accumulation for the same expected genetic gain.The use of ROH-based genealogical relatedness in GM achieved faster genetic gains than using relatedness based on individual SNPs.The GROH-based GM schemes with the maximum genetic gain resulted in 0.9%-2.6%higher rates of genetic gainΔG,and 13%-83.3%lowerΔF than positive assortative mating regardless of heritability.The rates of inbreeding were always the fastest with positive assortative mating.Results from a purebred Large White pig population,confirmed that GM with ROH-based GRM was more efficient than traditional mating schemes.Conclusion Compared with traditional mating schemes,genomic mating can not only achieve sustainable genetic progress but also effectively control the rates of inbreeding accumulation in the population.Our findings demonstrated that breeders should consider using genomic mating for genetic improvement of pigs.
基金Supported by the Guangxi Science and Technology Base and Talent Special Project (No.AD23026114)。
文摘Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata.
基金financially supported from the Shanxi Youth Science Research Project(Grant No.20210302124067)the Shanxi Agricultural University Doctoral Research Startup Project(Grant No.2021BQ32)+2 种基金the Shanxi Provincial Doctoral Graduates and Postdoctoral ResearchersWorking in Shanxi Reward Fund Research Project(Grant No.SXBYKY2021075)the National Youth Science Foundation Project(Grant No.32202456)the earmarked fund for Modern Agro-Industry Technology Research System.
文摘Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape varieties with different lengths of small inflorescences,namely‘Musct Hambourg’grape(Vitis vinifera),‘Concord’grape(Vitis labrusca),‘ShanPuTao’grape(Vitis amurensis)and‘GongNiang2Hao’grape(Vitis amurensis×Vitis vinifera)were used as test materials.Four varieties ovary were significant differences by means of stereomicroscope,paraffin section.The expression of ovary determining gene VvAGAMOUS(VvAG)and its development related genes VvCRABS CLAW(VvCRC)and VvAGAMOUS-LIKE 11(VvAGL11)with similar functions during the development of different grape varieties were preliminarily explored using fluorescence quantitative test.The relationship between VvAG and VvCRC,VvAG and VvAGL11 were analyzed using Y1H assay.Our results showed that there were obvious abdominal sutures on the surface of expect for‘Musct Hambourg’grape,and existing poly carpels.The ovary development of‘ShanPuTao’and‘GongNiang2Hao’grape was completed when the inflorescence length was less than 1 cm,while the‘Concord’and‘Musct Hambourg’grape were fully developed when the length of inflorescence was 3–4 and 4–5 cm,respectively.VvAG and VvCRC began to express in large quantities after the formation of stamen primordia,while VvAGL11 during the forming of ovule primordia.Therefore,VvAG and VvCRC mainly regulated the development of stamens and carpels and also promote the development of ovules,while VvAGL11 major regulated the development of ovules.The promoters of VvCRC and VvAGL11 were bound by VvAG.This study provides an important theoretical basis for further research on the molecular mechanism of grape ovary development.
基金supported by the National Natural Science Foundation of China(Nos.82071104 and 81900988)the Clinical Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(No.JYLJ201908).
文摘The oral microbiota is a vital part of the human microbiota that functions in various physiological processes and ishighly relevant to cancers and other diseases. With the alterations of host immune competence, the homeostatic balanceexisting between the oral microbiota and host may be disturbed and result in the development of diseases. Numerousobservations have suggested that small RNAs are key regulators of bacterial pathogenesis and bacteria-host interactions.Further, bacterial small RNAs are considered to be promising biomarkers for the development of novel, and efficacioustherapies for oral dysbiosis. Mechanistic insights into how oral pathogens communicate with other bacteria or host cellsin oral cancers via small RNAs are hot topics of research. Current studies also have begun to elucidate the key role oforal microbiota in the development of systemic diseases. This article discusses existing findings and nascent mechanismsgoverning the small RNA-based interactions between oral microbiota and associated diseases. The knowledge of suchinteractions is key in planning approaches to reverse dysbiosis to achieve health.
基金the National Natural Science Foundation of China(Grants Nos.92065204,12075128,T2225008,12174342,12274368,12274367,U20A2076,and 11725419)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300200)+2 种基金the Zhejiang Province Key Research and Development Program(Grant No.2020C01019)supported by Tsinghua Universitythe Shanghai Qi Zhi Institute。
文摘Non-Abelian anyons are exotic quasiparticle excitations hosted by certain topological phases of matter.They break the fermion-boson dichotomy and obey non-Abelian braiding statistics:their interchanges yield unitary operations,rather than merely a phase factor,in a space spanned by topologically degenerate wavefunctions.They are the building blocks of topological quantum computing.However,experimental observation of non-Abelian anyons and their characterizing braiding statistics is notoriously challenging and has remained elusive hitherto,in spite of various theoretical proposals.Here,we report an experimental quantum digital simulation of projective non-Abelian anyons and their braiding statistics with up to 68 programmable superconducting qubits arranged on a two-dimensional lattice.By implementing the ground states of the toric-code model with twists through quantum circuits,we demonstrate that twists exchange electric and magnetic charges and behave as a particular type of non-Abelian anyons,i.e.,the Ising anyons.In particular,we show experimentally that these twists follow the fusion rules and non-Abelian braiding statistics of the Ising type,and can be explored to encode topological logical qubits.Furthermore,we demonstrate how to implement both single-and two-qubit logic gates through applying a sequence of elementary Pauli gates on the underlying physical qubits.Our results demonstrate a versatile quantum digital approach for simulating non-Abelian anyons,offering a new lens into the study of such peculiar quasiparticles.
文摘Radix Astragali has been an important traditional Chinese herbal medicine for over 2000 years. It is derived from two plant species, namely, Astragalus mongholicus [Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao] and Astragalus membranaceus [Astragalus membranaceus (Fisch.) Bge.] (Leguminosae ), according to the Pharmacopoeia of the People’s Republic of China. In this study, the genetic diversity and genetic relationships of Radix Astragali in China were analyzed by Inter-Simple Sequence Repeat (ISSR) markers. A total of 25 highly polymorphic ISSR primers were selected to amplify 95 Radix Astragali samples. Among 273 DNA bands amplified, 213 are polymorphic (percentage of polymorphic bands: 78%). The average value of the amplified bands was 10.9 for each primer, and the number varied from 4 to 20. The genetic diversity of the 95 Radix Astragali samples was analyzed by using POPGENE 1.32 software. The Nei’s genetic diversity index (h) and Shannon’s information index (I ) were 0.3590 and 0.5308, respectively, which indicated the abundant genetic diversity of Radix Astragali . The level of genetic diversity in A. membranaceus (h: 0.3109, I : 0.4657) was slightly lower than that in A. mongholicus (h: 0.3364, I : 0.4969). Considering the average genetic similarity coefficient by NTSYS analysis to cluster the A. membranaceus of nine habitats and A. mongholicus of five habitats, Radix Astragali samples were clustered into two groups according to place of origin. This clustering is different from traditional clustering, which divides groups according to species. Results obtained from this study will provide a theoretical basis for the molecular study on germplasm resources of Radix Astragali .
基金supported by the National Nature Science Foundation of China(21476098,21471069,21576123)International Postdoctoral Exchange Fellowship Program of China Postdoctoral Council(20150060)~~
文摘燃料电池可以直接将化学能转化为电能,是一种极具前景的能量转换设备.目前,铂碳是燃料电池阴极氧还原反应(ORR)常用催化剂,但是铂储量低、价格昂贵、稳定性差且容易受CO毒化,极大地限制了其在燃料电池商业化中的应用.因此,探索价格低廉、性能优越的非贵金属氧还原催化剂显得尤为重要.大量研究发现,碳基材料具有优越的氧还原性能和良好的电化学稳定性.同时,自然界的生物质种类丰富,是很好的碳基材料来源.本文选取日常生活中最常见的富碳生物质废纸作为碳源,二氰二胺和乙酰丙酮钴分别作为氮源和钴源,经过特定气氛下的梯度升温制得非贵金属钴、氮共掺杂碳纳米管负载多孔碳氧还原催化剂(Co/N/CNT@PC-800).考察了杂原子N掺杂、过渡金属Co掺杂对材料形貌和性能的影响,采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、拉曼(Raman)光谱、氮气吸附-脱附和X射线光电子能谱(XPS)等表征方法探究了Co/N/CNT@PC-800材料的组成与结构,通过循环伏安法(CV)以及线性扫描伏安法(LSV)等电化学测试探究了其氧还原反应性能.SEM和TEM结果表明,Co/N/CNT@PC-800材料为表面生长着大量碳纳米管的多孔碳结构.这是因为二氰二胺和钴引入后,钴催化二氰二胺转化成碳纳米管.金属纳米粒子被封装在碳层之间和碳纳米管中而得到有效的保护,使之不易被酸腐蚀.同时,Co和N元素可以形成更多的活性位点(Co–Nx),增强材料ORR活性.SEM和氮气吸附-脱附结果显示,掺杂Co后,材料的介孔结构会进一步增加,形成微孔/介孔结构.多孔结构可以增强ORR相关物质(O2,H+,OH.,H2O)的传质速率,提升反应速率,达到增强ORR活性的效果.除此之外,多孔的结构也可以促进活性位点的暴露,进而提升材料的ORR性能.XPS结果显示,Co/N/CNT@PC-800材料中N主要以吡啶氮和石墨氮两种形式存在,而这两种类型的氮有利于促进ORR的进行.Raman光谱结果显示,在引入N和Co元素后,材料的缺陷结构有所增加,因而有利于电催化氧还原反应性能的提升.另外,LSV测试结果表明,在引入Co或者N后,材料催化ORR的起始电位、半波电位、极限电流密度均有小幅改善;同时引入Co和N后,Co/N/CNT@PC-800材料催化ORR的起始电位(0.005 V vs.Ag/AgCl)、半波电位(.0.173 V vs.Ag/AgCl)、极限电流密度(.4.117 mA cm.2)均有较大幅度的改善.通过Koutecky-Levich(K-L)方程计算以及旋转环盘电极测得的氧还原极化曲线结果均表明,Co/N/CNT@PC-800材料的氧还原反应是通过准四电子反应转移路径进行.此外,循环(3000圈CV)稳定性测试结果证明,Co/N/CNT@PC-800材料比商业化的Pt/C具有更好的稳定性.总之,本文采用简单的梯度升温法制备出非贵金属钴、氮共掺杂的碳基氧还原催化剂(Co/N/CNT@PC-800),为探索利用生物质制备电催化剂用于燃料电池提供了一种可供选择的途径.
文摘STSE(Science,Technology,Society and Environment)教育理念注重在情境化教学中促进学生对知识的理解和掌握,强调科学、技术、社会、环境的相互关系,并实现学生对社会发展和进步的进一步认识。本文以“北京冬奥会”这一热点事件为情境,基于STSE教育理念,通过将化学与北京冬奥会中社会、技术、环境等元素有机融合,阐述化学如何为北京冬奥会赋能,引导学生对化学产生兴趣,并在潜移默化中提升学生可持续发展的意识,为现代化科技强国建设培养化学类人才。