The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of...The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of restricted spaces on the properties of confined fluids.However,the situation of channel-wall is crucial but attracts less attention and remains unknown.To fundamentally understand the mechanism of channel-walls in nanoconfinement,we investigated the interaction between the counter-force of the liquid and interlamellar spacing of nanochannel walls by considering the effect of both spatial confinement and surface wettability.The results reveal that the nanochannel stables at only a few discrete spacing states when its confinement is within 1.4 nm.The quantized interlayer spacing is attributed to water molecules becoming laminated structures,and the stable states are corresponding to the monolayer,bilayer and trilayer water configurations,respectively.The results can potentially help to understand the characterized interlayers spacing of graphene oxide membrane in water.Our findings are hold great promise in design of ion filtration membrane and artificial water/ion channels.展开更多
The second magnetization peak(SMP)appears in most superconductors and is crucial for the understanding of vortex physics as well as the application.Although it is well known that the SMP is related to the type and qua...The second magnetization peak(SMP)appears in most superconductors and is crucial for the understanding of vortex physics as well as the application.Although it is well known that the SMP is related to the type and quantity of disorder/defects,the mechanism has not been universally understood.We selected three stoichiometric superconducting RbCa_(2)Fe_(4)As_(4)F_(2)single crystals with identical superconducting critical temperature T_(c)~31 K and similar self-field critical current density J_(c),but with different amounts of disorder/defects,to study the SMP effect.It is found that only the sample S2 with moderate disorder/defects shows significant SMP effect.The evolution of the normalized pinning force density f_(p)demonstrates that the dominant pinning mechanism changes from the weak pinning at low temperatures to strong pinning at high temperatures.The microstructure study for sample S2 reveals some expanded Ca_(2)F_(2)layers and dislocation defects in Rb Fe_(2)As_(2)layers.The normalized magnetic relaxation results indicate that the SMP is strongly associated with the elastic to plastic(E-P)vortex transition.As temperature increases,the SMP gradually evolves into a step-like shape and then becomes a sharp peak near the irreversibility field similar to what is usually observed in low-temperature superconductors.Our findings connect the low field SMP of high-temperature superconductors and the high field peak of lowtemperature superconductors,revealing the possible universal origin related to the E-P phase transition.展开更多
A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which h...A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which has a unique temperature-dependent backward energy transfer process from selftrapped state to^(4)T_(1)energy level of Mn,is used for triggering the temperature alarm.The LSC with redemitted CsPbI_(3)perovskite-polymer composite films on the glass substrate is used for power supply.The spectrally separated nature between the green-emitted OMHs for temperature alarm and red-emitted CsPbI3in LSC for power supply allows for probing the signal light of temperature-responsive OMHs without the interference of LSCs,making it possible to calibrate the temperature visually just by a self-powered brightness detection circuit with LED indicators.Taking advantage of LSC without hot spot effects plaguing the solar cells,as-prepared temperature alarm system can operate well on both sunny and cloudy day.展开更多
Pears carry a gametophytic self-incompatibility(SI)system.In this system,S-RNase is the SI pistil determinant,and S-locus F-box brothers(SFBBs)are candidate pollen determinants.However,compared with apple,fewer SFBB g...Pears carry a gametophytic self-incompatibility(SI)system.In this system,S-RNase is the SI pistil determinant,and S-locus F-box brothers(SFBBs)are candidate pollen determinants.However,compared with apple,fewer SFBB genes were identified from pear,possibly caused by the lack of economic and effective methods.Here,we used transcriptome sequencing on‘Yali’(Pyrus bretschneideri)to obtain sequence fragments of SFBB genes and then used polymerase chain reaction(PCR)to amplify the whole sequence of SFBB genes.Twenty-seven SFBB genes,including22 full-length and five nonfull-length SFBB genes,were identified in‘Yali’(P.bretschneideri).SFBBs linkage analysis by PCR-enzyme-linked immunoassay(ELISA)showed that 12 SFBB genes belong to the S21 locus,and 15 SFBB genes belong to the S34 locus.Phylogenetic analysis showed that SFBB genes from Pyrus were divided into 26 types,more than the original eight types.The intrahaplotypic divergence of SFBBs is high and comparable to the allelic diversity of S-RNase,which is consistent with a nonself-recognition SI system.In addition,the expression level of PbrSFBBs in‘Jinzhui’,the only known haploid pollen of a self-compatible mutant,was mostly approximately two times higher than in‘Yali’,which may be the reason for the self-compatible mutant.展开更多
水系锌离子电池(ZIBs)以其低成本、高安全性和环境友好的优点受到了研究者的广泛关注,成为大规模电化学储能系统的理想选择之一。然而锌金属负极在应用时面临着锌枝晶生长、腐蚀反应和副反应等难以克服的障碍,严重制约了水系锌离子电池...水系锌离子电池(ZIBs)以其低成本、高安全性和环境友好的优点受到了研究者的广泛关注,成为大规模电化学储能系统的理想选择之一。然而锌金属负极在应用时面临着锌枝晶生长、腐蚀反应和副反应等难以克服的障碍,严重制约了水系锌离子电池的发展。探索可替代锌金属的储锌负极是应对上述问题的有效策略,因此研究者围绕过渡金属氧化物、硫化物和导电聚合物开展了深入研究。以TiX_(2)(X=S,Se)为代表的二维过渡金属硫族化合物(TMDs)具有较大的层间距和快速的离子传输通道,可作为锌离子电池的负极,但其储锌反应机制尚未得到完整的揭示。在本文中,我们使用密度泛函理论(DFT)计算方法系统地研究锌离子在TiX_(2)中的嵌入反应。首先我们采用群论去描述嵌锌TiX_(2)的稳定层间构型的特点,定义了一个依赖于超胞并且只涉及平移旋转两种对称操作的群,其子群可以用来描述层间构型的对称性,而且用来描述最稳定构型的子群总是倾向于有最大的阶数。基于该计算得到的一系列对应于不同放电深度的TiX_(2)的稳定结构,我们发现TiS_(2)和TiSe_(2)两种材料在锌嵌入/脱出过程中的开路电压(OCV)均低于0.5V。态密度(DOS)的计算结果表明TiX_(2)具有很好的电子导电性,而分波态密度(PDOS)的结果显示随着锌的嵌入闭壳层的Ti^(4+)还原成开壳层的Ti^(3+),并且伴随着Zn―X键的生成。Bader电荷分析的结果表明随着X的嵌入,X相比Ti得到了更多的负电荷,意味着X也参与了TiX_(2)的氧化还原过程。爬坡弹性带方法(CINEB)计算的结果证实了Zn^(2+)在TiX_(2)中具有较低的扩散能垒(对于TiS_(2)是0.333 e V,对于TiSe_(2)是0.338e V)。本文的研究结果不仅从本质上证明了TiX_(2)适合作为锌离子电池的嵌锌负极材料,而且为其他高性能TMDs电池材料的DFT研究提供了新的见解。展开更多
The author list originally given in Wang et al. Chin. Phys. B 31 108702 (2022) has been amended to remove four authors, Hua Li, Bin Wu, Jun Guo and Chenqi Xu, who believe their contributions are more suitable to be cr...The author list originally given in Wang et al. Chin. Phys. B 31 108702 (2022) has been amended to remove four authors, Hua Li, Bin Wu, Jun Guo and Chenqi Xu, who believe their contributions are more suitable to be credited in the acknowledgments.展开更多
Recognized as a pivotal developmental transition,flowering marks the continuation of a plant’s life cycle.Vernalization and pho-toperiod are two major flowering pathways orchestrating numerous florigenic signals.Meth...Recognized as a pivotal developmental transition,flowering marks the continuation of a plant’s life cycle.Vernalization and pho-toperiod are two major flowering pathways orchestrating numerous florigenic signals.Methylation,including histone,DNA and RNA methylation,is one of the recent foci in plant development.Considerable studies reveal that methylation seems to show an increasing potential regulatory role in plant flowering via altering relevant gene expression without altering the genetic basis.However,little has been reviewed about whether and how methylation acts on vernalization-and photoperiod-induced flowering before and after FLOWERING LOCUS C(FLC)reactivation,what role RNA methylation plays in vernalization-and photoperiod-induced flowering,how methylation participates simultaneously in both vernalization-and photoperiod-induced flowering,the heritability of methylation memory under the vernalization/photoperiod pathway,and whether and how methylation replaces vernalization/photoinduction to regulate flowering.Our review provides insight about the crosstalk among the genetic control of the flowering gene network,methylation(methyltransferases/demethylases)and external signals(cold,light,sRNA and phytohormones)in vernalization and photoperiod pathways.The existing evidence that RNA methylation may play a potential regulatory role in vernalization-and photoperiod-induced flowering has been gathered and represented for the first time.This review speculates about and discusses the possibility of substituting methylation for vernalization and photoinduction to promote flowering.Current evidence is utilized to discuss the possibility of future methylation reagents becoming flowering regulators at the molecular level.展开更多
Recently there has been a resurgence of interest in cyclic peptides due to their therapeutic advantages in terms of potency, permeability, proteolytic stability, and unique selectivity relative to traditional smaller ...Recently there has been a resurgence of interest in cyclic peptides due to their therapeutic advantages in terms of potency, permeability, proteolytic stability, and unique selectivity relative to traditional smaller drug molecules. Cyclosporin is a family of cyclic peptides widely used as autoimmune suppression agents. Cyclosporin analogs consist of eleven amino acids with the main difference lying at the side chain of its amino acid residues. In this study, a single step separation method was developed utilizing Supercritical Fluid Chromatography (SFC) to resolve five naturally occurring cyclosporin analogs (Cyclosporin A, B, C, D, and H) on a bare silica-packed column. The optimized method involved use of ethanol-modified carbon dioxide as mobile phase on a bare silica column at 80 °C and UV detection at 220 nm. Although column temperature and back pressure generally had insignificant effect on SFC separation, it was found in our study that increasing temperature and pressure greatly improved peak shape and resolution.展开更多
The equilibrium lattice parameter, relative volume V/V0, elastic constants Cij, and bulk modulus of titanium nitride are successfully obtained using the ab initio planewave pseudopotential (PW-PP) method within the ...The equilibrium lattice parameter, relative volume V/V0, elastic constants Cij, and bulk modulus of titanium nitride are successfully obtained using the ab initio planewave pseudopotential (PW-PP) method within the framework of density functional theory. The quasi-harmonic Debye model, using a set of total energy vs molar volume obtained with the PW-PP method, is applied to the study of the elastic properties and vibrational effects. We analyze the relationship between the bulk modulus and temperature up to 2000 K and obtain the relationship between bulk modulus B and pressure at different temperatures. It is found that the bulk modulus B increases monotonously with increasing pressure and decreases with increasing temperature. Moreover, the Debye temperature is determined from the non-equilibrium Gibbs functions.展开更多
Copper ions can promote amyloid diseases that are associated with amyloid peptides, such as type 2 diabetes(T2D),Alzheimer's disease(AD), Parkinson's disease(PD), and amyotrophic lateral sclerosis(ALS). Howeve...Copper ions can promote amyloid diseases that are associated with amyloid peptides, such as type 2 diabetes(T2D),Alzheimer's disease(AD), Parkinson's disease(PD), and amyotrophic lateral sclerosis(ALS). However, the underlying molecular mechanism remains obscure. Here we present that Cu^(2+)is able to specifically bind to the backbone of T2D related human islet amyloid polypeptide(hIAPP) by forming a ring structure, which causes the reduction of Cu^(2+)to Cu^(+) to produce reactive oxygen species(ROS) and the modulation of hIAPP aggregation. Nuclear magnetic resonance spectroscopy showed that Cu^(2+)bound to the backbone of a turn region, His18-Ser21, which is critical for hIAPP aggregation.Ab initio calculations and x-ray absorption fine structure analyses revealed that Cu^(2+)simultaneously bound with both the amide nitrogen and carbonyl oxygen on the peptide backbone, resulting in a ring structure, and causing the reduction of Cu^(2+)to Cu^(+) to form a hIAPP-Cu^(+) complex. 2′,7′-dichlorodihydrofluorescin diacetate fluorescence measurements further indicated that this complex led to enhanced ROS levels in rat insulinoma cells. Additionally, thioflavin T fluorescence and atomic force microscopy measurements denoted that the backbone-Cu ring structure largely modulated hIAPP aggregation,including the inhibition of hIAPP fibrillation and the promotion of peptide oligomerization. These findings shed new light on the molecular mechanism of Cu^(2+)-induced amyloid toxicity involving both the enhancement of ROS and the modulation of hIAPP aggregation.展开更多
The friction at the liquid-solid interfaces is widely involved in various phenomena ranging from nanometer to micrometer scales. By the molecular dynamic(MD)simulation, the friction properties of liquid-solid interfac...The friction at the liquid-solid interfaces is widely involved in various phenomena ranging from nanometer to micrometer scales. By the molecular dynamic(MD)simulation, the friction properties of liquid-solid interfaces at the molecular level are calculated via the Green-Kubo relation. It is found that the system size will influence the value of the friction coefficient, especially for the solid surfaces with the larger polar charge. The value of the friction coefficient decreases with the increase in the system size and converges at large system sizes. The large polar charge will lead to a significant friction coefficient. However, the diffusion of water molecules on this surface is almost a constant, indicating that the diffusion coefficient seems to be independent of the system size and polar charge. This work provides insights for the selection of the system size in modeling the frictional properties of hydrophobic/hydrophilic surfaces.展开更多
Brain arteriovenous malformations(AVMs)are abnormal vessels that are prone to rupture,ausing life threatening intracerebral hemorrhage(ICH).Understanding the moleaular basis of pathogenesis,timely diagnosis,and treatm...Brain arteriovenous malformations(AVMs)are abnormal vessels that are prone to rupture,ausing life threatening intracerebral hemorrhage(ICH).Understanding the moleaular basis of pathogenesis,timely diagnosis,and treatment of brain AVMs are some of the urgent problems in neur osur gery.MiaoRNAs(miRNAs)are small endogenous RNAs that regulate gene-epression psttranscriptionally.MiRNAs are involved in almost all biological procsss,induding cell proliferation,apoptosis,and cell differentiation.Recent studies have shown that miRNAs an be involved in brain AVMs formation and rupture.There are also extracellular forms of miRNAs.Circulating miRNAs have been detected in the blood circulation and other body fluids.Owing to their stability and resistance to endogenous RNase activity,circulating miRNAs have been proposed as diagnostic and prognostic biomarkers for various diseases,such as tumors,cardiovascular and autoimmune diseases.In this review,we summarized the role of some miRNAs in brain AVMs pathogenesis and discussed their potential cdinical appliation as non-invasive biomarkers.展开更多
Artificial ion channels that enable high-efficiency ion transport have important implications in nanofluidics and biomedical applications such as drug delivery.Herein,we show a simulation-based chemical design of a bi...Artificial ion channels that enable high-efficiency ion transport have important implications in nanofluidics and biomedical applications such as drug delivery.Herein,we show a simulation-based chemical design of a biomimetic sodium channel that possesses permeation rate and selectivity potentially higher than those of the state-of-the-art natural vertebrate voltage-gated sodium channels.Importantly,our theoretical findings have undergone empirical testing,aligning well with the Arrhenius law as derived from a diverse range of experimental results.The high-efficiency ion transport is achieved by anchoring the carboxylate functional groups within the channel filter.A key chemical guiding principle underlying the ion channel design is that the free-energy barrier for the Na+passage across the channel should be comparable to typical thermal energy at room temperature.With the implementation of the chemical design,we found that the relatively low free-energy barrier can be attributed to the compensation effect of the carboxylate groups to the partially lost oxygen shell of the ion within the ion channel,as well as to the consonant vibration of the ions inside and outside the channel.This mechanistic understanding brings new insight,at the molecular level,into the high-efficiency ion transport across the designed membrane channels.The proof of principle achieved from the simulations will stimulate future experimental confirmation and potential applications of the high-performance artificial channels in nanofluidics and in bioinspired iontronics.展开更多
Cardiac fibrosis caused by ventricular remodeling and dysfunction such as post-myocardial infarction(MI)can lead to heart failure.RNA N6-methyladenosine(m^(6)A)methylation has been shown to play a pivotal role in the ...Cardiac fibrosis caused by ventricular remodeling and dysfunction such as post-myocardial infarction(MI)can lead to heart failure.RNA N6-methyladenosine(m^(6)A)methylation has been shown to play a pivotal role in the occurrence and development of many illnesses.In investigating the biological function of the m^(6)A reader YTHDF1 in cardiac fibrosis,adeno-associated virus 9 was used to knock down or overexpress the YTHDF1 gene in mouse hearts,and MI surgery in vivo and transforming growth factor-β(TGF-β)-activated cardiac fibroblasts in vitro were performed to establish fibrosis models.Our results demonstrated that silencing YTHDF1 in mouse hearts can significantly restore impaired cardiac function and attenuate myocardial fibrosis,whereas YTHDF1 overexpression could further enhance cardiac dysfunction and aggravate the occurrence of ventricular pathological remodeling and fibrotic development.Mechanistically,zinc finger BED-type containing 6 mediated the transcriptional function of the YTHDF1 gene promoter.YTHDF1 augmented AXL translation and activated the TGF-β-Smad2/3 signaling pathway,thereby aggravating the occurrence and development of cardiac dysfunction and myocardial fibrosis.Consistently,our data indicated that YTHDF1 was involved in activation,proliferation,and migration to participate in cardiac fibrosis in vitro.Our results revealed that YTHDF1 could serve as a potential therapeutic target for myocardial fibrosis.展开更多
The NLRP3 inflammasome plays an essential role in resistance to bacterial infection. The nervous system secretes multiple neuropeptides affecting the nervous system as well as immune cells. The precise impact of the n...The NLRP3 inflammasome plays an essential role in resistance to bacterial infection. The nervous system secretes multiple neuropeptides affecting the nervous system as well as immune cells. The precise impact of the neuropeptide CGRP on NLRP3 inflammasome activation is still unclear. Here, we show that CGRP negatively regulates the antibacterial process of host cells. CGRP prevents NLRP3 inflammasome activation and reduces mature IL-1β secretion. Following NLRP3 inflammasome stimulation that triggers endosome leakage, CGRP internalized to endosomal compartments is released into the cell cytosol. Cytosolic CGRP binds directly to NLRP3 and dismantles the NLRP3-NEK7 complex, which is crucial for NLRP3 inflammasome activation. CGRP administration exacerbates bacterial infection, while the treatment with a CGRP antagonist has the opposite effect. Our study uncovers a unique role of CGRP in inhibiting inflammasome activation during infections, which might shed new light on antibacterial therapies in the future.展开更多
With the fabrication of high-performance thermoelectric(TE)materials,developments are being made in enhanc-ing the figure of merit,zT,of TE materials.Liquid-like binary copper selenide(Cu_(2) Se)chalcogenides recently...With the fabrication of high-performance thermoelectric(TE)materials,developments are being made in enhanc-ing the figure of merit,zT,of TE materials.Liquid-like binary copper selenide(Cu_(2) Se)chalcogenides recently gained significant recognition because of their anomalous but fascinating electrical and thermal transport perfor-mances.In this study,a facile synthesis technique was adopted in fabricating Cu_(2) Se nanoparticles using a rapid microwave-assisted hydrothermal route at different reaction times.The results were compared with those of the Cu_(2) Se solid-state(SS)sample synthesized using the traditional melting and annealing technique.X-ray diffrac-tion patterns revealed successful synthesis of nanoparticles and a phase transition from orthorhombic𝛼-phase and cubic𝛽-phase to a single orthorhombic structure after hot-pressing.Scanning electron microscopic images revealed that although the grain sizes of the nanoparticle(NP)bulk samples increased with the reaction time of the microwave hydrothermal process,the grain sizes were significantly smaller than that of the SS sample.Additionally,NP bulk samples exhibited plenty of nano-grains and pores that are absent in the SS sample.The size and distribution of the grains and pores were measured to study their effects on the transport of carriers and phonons.The NP30 sample exhibited the highest power factor of 983.3μW K−2 m at 673 K among the NP samples,exhibiting intermediate values of resistivity and Seebeck coefficient that are close to those of the SS sample.Moreover,the NP samples exhibited appreciably lower thermal conductivity than the SS sample that is attributed to strengthened phonon scattering.The minimum thermal conductivity of the NP05 sample,0.78 WK−1 m−1 at 348 K,is 1.7 times lower than that of the SS sample.Finally,a maximum zT of 0.56 at 673 K,being approximately 1.3 times higher than that of the SS sample owing to the optimized thermal conductivity,was achieved for the NP30 sample.This value is comparable to or higher than that reported for Cu_(2) Se synthesized using the traditional SS method.Investigations revealed that the proposed microwave hydrothermal synthesis technique is a facile,rapid,and reliable method that results in Cu_(2) Se alloys with excellent TE performance.展开更多
Titanium dioxide(TiO_(2))has attracted considerable research attentions for its promising applications in solar cells and photocatalytic devices.However,the intrinsic challenge lies in the relatively low energy conver...Titanium dioxide(TiO_(2))has attracted considerable research attentions for its promising applications in solar cells and photocatalytic devices.However,the intrinsic challenge lies in the relatively low energy conversion efficiency of TiO_(2),primarily attributed to the substantial band gaps(exceeding 3.0 eV)associated with its rutile and anatase phases.Leveraging multi-objective global optimization,we have identified two quasi-layered ternary Ti-O-S crystals,composed of titanium,oxygen,and sulfur.The calculations of formation energy,phonon dispersions,and thermal stability confirm the chemical,dynamical and thermal stability of these newly discovered phases.Employing the state-of-art hybrid density functional approach and many-body perturbation theory(quasiparticle GW approach and Bethe-Salpeter equation),we calculate the optical properties of both the TiOS phases.Significantly,both phases show favorable photocatalytic characteristics,featuring band gaps suitable for visible optical absorption and appropriate band alignments with water for effective charge carrier separation.Therefore,ternary compound TiOS holds the potential for achieving high-efficiency photochemical conversion,showing our multi-objective global optimization provides a new approach for novel environmental and energy materials design with multicomponent compounds.展开更多
基金support from the National Natural Science Foundation of China(Grant Nos.12372327,12372109,11972171)National Key R&D Program of China(Grant No.2023YFB4605101).
文摘The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of restricted spaces on the properties of confined fluids.However,the situation of channel-wall is crucial but attracts less attention and remains unknown.To fundamentally understand the mechanism of channel-walls in nanoconfinement,we investigated the interaction between the counter-force of the liquid and interlamellar spacing of nanochannel walls by considering the effect of both spatial confinement and surface wettability.The results reveal that the nanochannel stables at only a few discrete spacing states when its confinement is within 1.4 nm.The quantized interlayer spacing is attributed to water molecules becoming laminated structures,and the stable states are corresponding to the monolayer,bilayer and trilayer water configurations,respectively.The results can potentially help to understand the characterized interlayers spacing of graphene oxide membrane in water.Our findings are hold great promise in design of ion filtration membrane and artificial water/ion channels.
基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB25000000)the National Key R&D Program of China(Grant No.2018YFA0704300)+1 种基金the National Natural Science Foundation of China(Grant Nos.12204265 and 12204487)the Fundamental Research Funds for the Central Universities。
文摘The second magnetization peak(SMP)appears in most superconductors and is crucial for the understanding of vortex physics as well as the application.Although it is well known that the SMP is related to the type and quantity of disorder/defects,the mechanism has not been universally understood.We selected three stoichiometric superconducting RbCa_(2)Fe_(4)As_(4)F_(2)single crystals with identical superconducting critical temperature T_(c)~31 K and similar self-field critical current density J_(c),but with different amounts of disorder/defects,to study the SMP effect.It is found that only the sample S2 with moderate disorder/defects shows significant SMP effect.The evolution of the normalized pinning force density f_(p)demonstrates that the dominant pinning mechanism changes from the weak pinning at low temperatures to strong pinning at high temperatures.The microstructure study for sample S2 reveals some expanded Ca_(2)F_(2)layers and dislocation defects in Rb Fe_(2)As_(2)layers.The normalized magnetic relaxation results indicate that the SMP is strongly associated with the elastic to plastic(E-P)vortex transition.As temperature increases,the SMP gradually evolves into a step-like shape and then becomes a sharp peak near the irreversibility field similar to what is usually observed in low-temperature superconductors.Our findings connect the low field SMP of high-temperature superconductors and the high field peak of lowtemperature superconductors,revealing the possible universal origin related to the E-P phase transition.
基金supported by the Natural Science Foundation of China(22075043,21875034,61704093)。
文摘A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which has a unique temperature-dependent backward energy transfer process from selftrapped state to^(4)T_(1)energy level of Mn,is used for triggering the temperature alarm.The LSC with redemitted CsPbI_(3)perovskite-polymer composite films on the glass substrate is used for power supply.The spectrally separated nature between the green-emitted OMHs for temperature alarm and red-emitted CsPbI3in LSC for power supply allows for probing the signal light of temperature-responsive OMHs without the interference of LSCs,making it possible to calibrate the temperature visually just by a self-powered brightness detection circuit with LED indicators.Taking advantage of LSC without hot spot effects plaguing the solar cells,as-prepared temperature alarm system can operate well on both sunny and cloudy day.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFD1000107)National Natural Science Foundation of China(Grant No.32001983)the Natural Science Foundation of Jiangsu Province(Grant No.BK20190896)。
文摘Pears carry a gametophytic self-incompatibility(SI)system.In this system,S-RNase is the SI pistil determinant,and S-locus F-box brothers(SFBBs)are candidate pollen determinants.However,compared with apple,fewer SFBB genes were identified from pear,possibly caused by the lack of economic and effective methods.Here,we used transcriptome sequencing on‘Yali’(Pyrus bretschneideri)to obtain sequence fragments of SFBB genes and then used polymerase chain reaction(PCR)to amplify the whole sequence of SFBB genes.Twenty-seven SFBB genes,including22 full-length and five nonfull-length SFBB genes,were identified in‘Yali’(P.bretschneideri).SFBBs linkage analysis by PCR-enzyme-linked immunoassay(ELISA)showed that 12 SFBB genes belong to the S21 locus,and 15 SFBB genes belong to the S34 locus.Phylogenetic analysis showed that SFBB genes from Pyrus were divided into 26 types,more than the original eight types.The intrahaplotypic divergence of SFBBs is high and comparable to the allelic diversity of S-RNase,which is consistent with a nonself-recognition SI system.In addition,the expression level of PbrSFBBs in‘Jinzhui’,the only known haploid pollen of a self-compatible mutant,was mostly approximately two times higher than in‘Yali’,which may be the reason for the self-compatible mutant.
文摘水系锌离子电池(ZIBs)以其低成本、高安全性和环境友好的优点受到了研究者的广泛关注,成为大规模电化学储能系统的理想选择之一。然而锌金属负极在应用时面临着锌枝晶生长、腐蚀反应和副反应等难以克服的障碍,严重制约了水系锌离子电池的发展。探索可替代锌金属的储锌负极是应对上述问题的有效策略,因此研究者围绕过渡金属氧化物、硫化物和导电聚合物开展了深入研究。以TiX_(2)(X=S,Se)为代表的二维过渡金属硫族化合物(TMDs)具有较大的层间距和快速的离子传输通道,可作为锌离子电池的负极,但其储锌反应机制尚未得到完整的揭示。在本文中,我们使用密度泛函理论(DFT)计算方法系统地研究锌离子在TiX_(2)中的嵌入反应。首先我们采用群论去描述嵌锌TiX_(2)的稳定层间构型的特点,定义了一个依赖于超胞并且只涉及平移旋转两种对称操作的群,其子群可以用来描述层间构型的对称性,而且用来描述最稳定构型的子群总是倾向于有最大的阶数。基于该计算得到的一系列对应于不同放电深度的TiX_(2)的稳定结构,我们发现TiS_(2)和TiSe_(2)两种材料在锌嵌入/脱出过程中的开路电压(OCV)均低于0.5V。态密度(DOS)的计算结果表明TiX_(2)具有很好的电子导电性,而分波态密度(PDOS)的结果显示随着锌的嵌入闭壳层的Ti^(4+)还原成开壳层的Ti^(3+),并且伴随着Zn―X键的生成。Bader电荷分析的结果表明随着X的嵌入,X相比Ti得到了更多的负电荷,意味着X也参与了TiX_(2)的氧化还原过程。爬坡弹性带方法(CINEB)计算的结果证实了Zn^(2+)在TiX_(2)中具有较低的扩散能垒(对于TiS_(2)是0.333 e V,对于TiSe_(2)是0.338e V)。本文的研究结果不仅从本质上证明了TiX_(2)适合作为锌离子电池的嵌锌负极材料,而且为其他高性能TMDs电池材料的DFT研究提供了新的见解。
文摘The author list originally given in Wang et al. Chin. Phys. B 31 108702 (2022) has been amended to remove four authors, Hua Li, Bin Wu, Jun Guo and Chenqi Xu, who believe their contributions are more suitable to be credited in the acknowledgments.
基金This work was supported by the National Key Research and Development Program(2018YFD1000800)the National Natural Science Foundation of China(31160398,31560563,31860568,32072559,and 32102370)+2 种基金the Key Research and Development Program of Gansu Province,China(21YF5WA096)the Natural Science Foundation of Gansu Province,China(1606RJZA073 and 1606RJZA077)the Research Fund of Higher Education of Gansu,China(2018C-14 and 2019B-082).We are grateful to members of our laboratory for helpful criticism and advice.
文摘Recognized as a pivotal developmental transition,flowering marks the continuation of a plant’s life cycle.Vernalization and pho-toperiod are two major flowering pathways orchestrating numerous florigenic signals.Methylation,including histone,DNA and RNA methylation,is one of the recent foci in plant development.Considerable studies reveal that methylation seems to show an increasing potential regulatory role in plant flowering via altering relevant gene expression without altering the genetic basis.However,little has been reviewed about whether and how methylation acts on vernalization-and photoperiod-induced flowering before and after FLOWERING LOCUS C(FLC)reactivation,what role RNA methylation plays in vernalization-and photoperiod-induced flowering,how methylation participates simultaneously in both vernalization-and photoperiod-induced flowering,the heritability of methylation memory under the vernalization/photoperiod pathway,and whether and how methylation replaces vernalization/photoinduction to regulate flowering.Our review provides insight about the crosstalk among the genetic control of the flowering gene network,methylation(methyltransferases/demethylases)and external signals(cold,light,sRNA and phytohormones)in vernalization and photoperiod pathways.The existing evidence that RNA methylation may play a potential regulatory role in vernalization-and photoperiod-induced flowering has been gathered and represented for the first time.This review speculates about and discusses the possibility of substituting methylation for vernalization and photoinduction to promote flowering.Current evidence is utilized to discuss the possibility of future methylation reagents becoming flowering regulators at the molecular level.
文摘Recently there has been a resurgence of interest in cyclic peptides due to their therapeutic advantages in terms of potency, permeability, proteolytic stability, and unique selectivity relative to traditional smaller drug molecules. Cyclosporin is a family of cyclic peptides widely used as autoimmune suppression agents. Cyclosporin analogs consist of eleven amino acids with the main difference lying at the side chain of its amino acid residues. In this study, a single step separation method was developed utilizing Supercritical Fluid Chromatography (SFC) to resolve five naturally occurring cyclosporin analogs (Cyclosporin A, B, C, D, and H) on a bare silica-packed column. The optimized method involved use of ethanol-modified carbon dioxide as mobile phase on a bare silica column at 80 °C and UV detection at 220 nm. Although column temperature and back pressure generally had insignificant effect on SFC separation, it was found in our study that increasing temperature and pressure greatly improved peak shape and resolution.
基金supported by the Scientific Research Project from Hubei Provincial Department of Education(Q20181808)the Research and Innovation Initiatives of Wuhan Polytechnic University(2018J04,2018Y07)~~
基金supported by the Science and Technology of Henan Province in China(No.082300410050)the Program for Science and Technology Innovation Talentsin Universities of Henan Province in China(Grant No.2008HASTIT008)
文摘The equilibrium lattice parameter, relative volume V/V0, elastic constants Cij, and bulk modulus of titanium nitride are successfully obtained using the ab initio planewave pseudopotential (PW-PP) method within the framework of density functional theory. The quasi-harmonic Debye model, using a set of total energy vs molar volume obtained with the PW-PP method, is applied to the study of the elastic properties and vibrational effects. We analyze the relationship between the bulk modulus and temperature up to 2000 K and obtain the relationship between bulk modulus B and pressure at different temperatures. It is found that the bulk modulus B increases monotonously with increasing pressure and decreases with increasing temperature. Moreover, the Debye temperature is determined from the non-equilibrium Gibbs functions.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12074208 and 11375256)the Natural Science Foundation of Jiangsu Province (Grant No. BK20200176)+2 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions of China (Grant Nos. 20KJB140020 and 19KJB140005)Fundamental Research Project from Changzhou Science and Technology (Grant No. CJ20200029)the Jiangsu Province High-level Innovative and Entrepreneurial Talents Introduction Plan。
文摘Copper ions can promote amyloid diseases that are associated with amyloid peptides, such as type 2 diabetes(T2D),Alzheimer's disease(AD), Parkinson's disease(PD), and amyotrophic lateral sclerosis(ALS). However, the underlying molecular mechanism remains obscure. Here we present that Cu^(2+)is able to specifically bind to the backbone of T2D related human islet amyloid polypeptide(hIAPP) by forming a ring structure, which causes the reduction of Cu^(2+)to Cu^(+) to produce reactive oxygen species(ROS) and the modulation of hIAPP aggregation. Nuclear magnetic resonance spectroscopy showed that Cu^(2+)bound to the backbone of a turn region, His18-Ser21, which is critical for hIAPP aggregation.Ab initio calculations and x-ray absorption fine structure analyses revealed that Cu^(2+)simultaneously bound with both the amide nitrogen and carbonyl oxygen on the peptide backbone, resulting in a ring structure, and causing the reduction of Cu^(2+)to Cu^(+) to form a hIAPP-Cu^(+) complex. 2′,7′-dichlorodihydrofluorescin diacetate fluorescence measurements further indicated that this complex led to enhanced ROS levels in rat insulinoma cells. Additionally, thioflavin T fluorescence and atomic force microscopy measurements denoted that the backbone-Cu ring structure largely modulated hIAPP aggregation,including the inhibition of hIAPP fibrillation and the promotion of peptide oligomerization. These findings shed new light on the molecular mechanism of Cu^(2+)-induced amyloid toxicity involving both the enhancement of ROS and the modulation of hIAPP aggregation.
基金the National Natural Science Foundation of China(Nos.11605151,11675138,and 11422542)the Special Program for Applied Research on Super Computation of the NSFCGuangdong Joint Fund(the second phase)。
文摘The friction at the liquid-solid interfaces is widely involved in various phenomena ranging from nanometer to micrometer scales. By the molecular dynamic(MD)simulation, the friction properties of liquid-solid interfaces at the molecular level are calculated via the Green-Kubo relation. It is found that the system size will influence the value of the friction coefficient, especially for the solid surfaces with the larger polar charge. The value of the friction coefficient decreases with the increase in the system size and converges at large system sizes. The large polar charge will lead to a significant friction coefficient. However, the diffusion of water molecules on this surface is almost a constant, indicating that the diffusion coefficient seems to be independent of the system size and polar charge. This work provides insights for the selection of the system size in modeling the frictional properties of hydrophobic/hydrophilic surfaces.
基金supported by National Natural Science Foundations of China(81971135)Natural Science Foundations of Heilongjiang(YQ2020H014)+2 种基金“Chunhui Plan”of Ministry of Education(HLJ2019009)Distinguished Young Foundations of the First Afiliated Hospital of Harbin Medical University(HYD2020JQ0014)The reported study was funded by RFBR and NSFC,Project No.21-515-53017.
文摘Brain arteriovenous malformations(AVMs)are abnormal vessels that are prone to rupture,ausing life threatening intracerebral hemorrhage(ICH).Understanding the moleaular basis of pathogenesis,timely diagnosis,and treatment of brain AVMs are some of the urgent problems in neur osur gery.MiaoRNAs(miRNAs)are small endogenous RNAs that regulate gene-epression psttranscriptionally.MiRNAs are involved in almost all biological procsss,induding cell proliferation,apoptosis,and cell differentiation.Recent studies have shown that miRNAs an be involved in brain AVMs formation and rupture.There are also extracellular forms of miRNAs.Circulating miRNAs have been detected in the blood circulation and other body fluids.Owing to their stability and resistance to endogenous RNase activity,circulating miRNAs have been proposed as diagnostic and prognostic biomarkers for various diseases,such as tumors,cardiovascular and autoimmune diseases.In this review,we summarized the role of some miRNAs in brain AVMs pathogenesis and discussed their potential cdinical appliation as non-invasive biomarkers.
基金supported by the National Natural Science Foundation of China(Nos.12374214,12022508,12074394,T2241002,12204547,and 12225511)National Key Research and Development Program of China(No.2021YFA1200404)+1 种基金National Defense Technology Innovation Special Zone and sponsored by Shanghai Rising-Star Program(No.23QA1404200)support by Hong Kong Global STEM Professorship Scheme and and a GRF grant(11204123)from the Research Grants Council of Hong Kong.
文摘Artificial ion channels that enable high-efficiency ion transport have important implications in nanofluidics and biomedical applications such as drug delivery.Herein,we show a simulation-based chemical design of a biomimetic sodium channel that possesses permeation rate and selectivity potentially higher than those of the state-of-the-art natural vertebrate voltage-gated sodium channels.Importantly,our theoretical findings have undergone empirical testing,aligning well with the Arrhenius law as derived from a diverse range of experimental results.The high-efficiency ion transport is achieved by anchoring the carboxylate functional groups within the channel filter.A key chemical guiding principle underlying the ion channel design is that the free-energy barrier for the Na+passage across the channel should be comparable to typical thermal energy at room temperature.With the implementation of the chemical design,we found that the relatively low free-energy barrier can be attributed to the compensation effect of the carboxylate groups to the partially lost oxygen shell of the ion within the ion channel,as well as to the consonant vibration of the ions inside and outside the channel.This mechanistic understanding brings new insight,at the molecular level,into the high-efficiency ion transport across the designed membrane channels.The proof of principle achieved from the simulations will stimulate future experimental confirmation and potential applications of the high-performance artificial channels in nanofluidics and in bioinspired iontronics.
基金funded by the National Natural Science Foundation of China(Nos.82104168 and U21A20339)the China Postdoctoral Science Foundation(Nos.2021M693832)Heilongjiang Province Postdoctoral Science Foundation(No.LBH-Z20174).
文摘Cardiac fibrosis caused by ventricular remodeling and dysfunction such as post-myocardial infarction(MI)can lead to heart failure.RNA N6-methyladenosine(m^(6)A)methylation has been shown to play a pivotal role in the occurrence and development of many illnesses.In investigating the biological function of the m^(6)A reader YTHDF1 in cardiac fibrosis,adeno-associated virus 9 was used to knock down or overexpress the YTHDF1 gene in mouse hearts,and MI surgery in vivo and transforming growth factor-β(TGF-β)-activated cardiac fibroblasts in vitro were performed to establish fibrosis models.Our results demonstrated that silencing YTHDF1 in mouse hearts can significantly restore impaired cardiac function and attenuate myocardial fibrosis,whereas YTHDF1 overexpression could further enhance cardiac dysfunction and aggravate the occurrence of ventricular pathological remodeling and fibrotic development.Mechanistically,zinc finger BED-type containing 6 mediated the transcriptional function of the YTHDF1 gene promoter.YTHDF1 augmented AXL translation and activated the TGF-β-Smad2/3 signaling pathway,thereby aggravating the occurrence and development of cardiac dysfunction and myocardial fibrosis.Consistently,our data indicated that YTHDF1 was involved in activation,proliferation,and migration to participate in cardiac fibrosis in vitro.Our results revealed that YTHDF1 could serve as a potential therapeutic target for myocardial fibrosis.
文摘The NLRP3 inflammasome plays an essential role in resistance to bacterial infection. The nervous system secretes multiple neuropeptides affecting the nervous system as well as immune cells. The precise impact of the neuropeptide CGRP on NLRP3 inflammasome activation is still unclear. Here, we show that CGRP negatively regulates the antibacterial process of host cells. CGRP prevents NLRP3 inflammasome activation and reduces mature IL-1β secretion. Following NLRP3 inflammasome stimulation that triggers endosome leakage, CGRP internalized to endosomal compartments is released into the cell cytosol. Cytosolic CGRP binds directly to NLRP3 and dismantles the NLRP3-NEK7 complex, which is crucial for NLRP3 inflammasome activation. CGRP administration exacerbates bacterial infection, while the treatment with a CGRP antagonist has the opposite effect. Our study uncovers a unique role of CGRP in inhibiting inflammasome activation during infections, which might shed new light on antibacterial therapies in the future.
基金supported financially by the National Key R&D Pro-gram of China(2017YFE0195200)the Natural Science Fund of China(under grant nos.51871134,52171216,and 52111530034)+1 种基金the Science Fund of Shandong Province(under grant no.ZR2019MEM007)the Qilu Young Scholar Program of Shandong University.
文摘With the fabrication of high-performance thermoelectric(TE)materials,developments are being made in enhanc-ing the figure of merit,zT,of TE materials.Liquid-like binary copper selenide(Cu_(2) Se)chalcogenides recently gained significant recognition because of their anomalous but fascinating electrical and thermal transport perfor-mances.In this study,a facile synthesis technique was adopted in fabricating Cu_(2) Se nanoparticles using a rapid microwave-assisted hydrothermal route at different reaction times.The results were compared with those of the Cu_(2) Se solid-state(SS)sample synthesized using the traditional melting and annealing technique.X-ray diffrac-tion patterns revealed successful synthesis of nanoparticles and a phase transition from orthorhombic𝛼-phase and cubic𝛽-phase to a single orthorhombic structure after hot-pressing.Scanning electron microscopic images revealed that although the grain sizes of the nanoparticle(NP)bulk samples increased with the reaction time of the microwave hydrothermal process,the grain sizes were significantly smaller than that of the SS sample.Additionally,NP bulk samples exhibited plenty of nano-grains and pores that are absent in the SS sample.The size and distribution of the grains and pores were measured to study their effects on the transport of carriers and phonons.The NP30 sample exhibited the highest power factor of 983.3μW K−2 m at 673 K among the NP samples,exhibiting intermediate values of resistivity and Seebeck coefficient that are close to those of the SS sample.Moreover,the NP samples exhibited appreciably lower thermal conductivity than the SS sample that is attributed to strengthened phonon scattering.The minimum thermal conductivity of the NP05 sample,0.78 WK−1 m−1 at 348 K,is 1.7 times lower than that of the SS sample.Finally,a maximum zT of 0.56 at 673 K,being approximately 1.3 times higher than that of the SS sample owing to the optimized thermal conductivity,was achieved for the NP30 sample.This value is comparable to or higher than that reported for Cu_(2) Se synthesized using the traditional SS method.Investigations revealed that the proposed microwave hydrothermal synthesis technique is a facile,rapid,and reliable method that results in Cu_(2) Se alloys with excellent TE performance.
基金Project supported by the Natural Science Foundation of WIUCAS (Grant Nos.WIUCASQD2023004 and WIUCASQD2022025)the National Natural Science Foundation of China (Grant Nos.12304006,12104452,12022508,12074394,and 12374061)+1 种基金the Shanghai Science and Technology Innovation Action Plan (Grant No.23JC1401400)the Natural Science Foundation of Wenzhou (Grant No.L2023005)。
文摘Titanium dioxide(TiO_(2))has attracted considerable research attentions for its promising applications in solar cells and photocatalytic devices.However,the intrinsic challenge lies in the relatively low energy conversion efficiency of TiO_(2),primarily attributed to the substantial band gaps(exceeding 3.0 eV)associated with its rutile and anatase phases.Leveraging multi-objective global optimization,we have identified two quasi-layered ternary Ti-O-S crystals,composed of titanium,oxygen,and sulfur.The calculations of formation energy,phonon dispersions,and thermal stability confirm the chemical,dynamical and thermal stability of these newly discovered phases.Employing the state-of-art hybrid density functional approach and many-body perturbation theory(quasiparticle GW approach and Bethe-Salpeter equation),we calculate the optical properties of both the TiOS phases.Significantly,both phases show favorable photocatalytic characteristics,featuring band gaps suitable for visible optical absorption and appropriate band alignments with water for effective charge carrier separation.Therefore,ternary compound TiOS holds the potential for achieving high-efficiency photochemical conversion,showing our multi-objective global optimization provides a new approach for novel environmental and energy materials design with multicomponent compounds.