This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal(I-phase)precipitates.Although exhibiting tr...This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal(I-phase)precipitates.Although exhibiting traditional basal texture,it owns an exceptional CYS/TYS as high as~1.17.Electron back-scattered diffraction(EBSD)and transmission electron microscopy(TEM)examinations indicate pyramidal and prismatic dislocations plus tensile twinning being activated after immediate yielding in compression while basal and non-basal dislocations in tension.I-phase particles transferred the concentrated stress by self-twinning to provide the driving force for tensile twin initiating in neighboring grains,thereby significantly increasing the critical resolved shear stress of tensile twinning to possibly the level of pyramidal slip,finally leading to the dominance of pyramidal slip plus tensile twinning in texture grains.This results in a higher contribution on yield strength by~55 MPa in compression than in tension,which reasonably agrees with the experimental yield strength difference(~38 MPa).It can be concluded that I-phase particles influence deformation modes in tension and in compression,finally result in reversed yield strength asymmetry.展开更多
Components and crystal structures of the intermetallic phases in a gravity die-cast Mg-6.0Zn-1.5Nd-0.5Zr(wt%)alloy were investigated using transmission electron microscopy.The results indicate that this alloy has mult...Components and crystal structures of the intermetallic phases in a gravity die-cast Mg-6.0Zn-1.5Nd-0.5Zr(wt%)alloy were investigated using transmission electron microscopy.The results indicate that this alloy has multiple intermetallic phases and various inner faults.Totally,six eutectoid intermetallic phases,namely W(Mg Nd Zn_(3)),T(Mg_(39)Zn_(55)Nd_(6)),(Mg,Zr)Zn_(2),Z(Mg_(28)Zn_(65)Nd_(7)),H_(2)(Mg_(15)Zn_(70)Nd_(15)),and H1(Mg_(24)Zn_(64)Nd_(11)),were simultaneously observed at grain boundaries,and six precipitates(Z,Mg_(7)Zn_(3),T,Mg_(4)Zn_(7),β_(1)-Mg Zn_(2) and β_(2)-Mg Zn_(2))were found inα-Mg grains.Furthermore,faults like sub-grain boundaries,orientation domains(coherent with the same matching plane but with different orientations),stacking faults and twins were observed in the eutectoid intermetallic phases.Finally,some new orientation relationships between the known intermetallic phases were revealed.This paper can provide new insight into alloy design for Mg-Zn-RE(RE:rare earth)based alloys.展开更多
The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically investigated.In the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morpho...The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically investigated.In the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morphologies are identified as Mg_(3)Sm phase. In addition to Mg_(3)RE phase, Mg_(5)RE phase originated from Gd addition is observed in Gd-modified alloys. It should be noted that the lattice parameters of all the observed intermetallic compounds are significantly reduced by Zn segregation. The segregation behavior of Zn in Mg_(3)Sm phase is inhibited to some extent by Gd addition due to the electronegativity difference between Sm/Gd and Zn elements. In addition, the increased Gd content effectively leads to much more accumulation of solute atoms in front of the liquid-solid interface during solidification, which can prominently promote nucleation in liquid region and then refine grains. The tensile yield stress of the present alloys is thus improved with increasing Gd addition. Finally, Gd-modified alloys exhibit significantly age-hardening effect, which can be mainly attributed to the high-volume fraction and high density nano-scale precipitates.展开更多
An ensemble Kalman filter(EnKF) combined with the Advanced Research Weather Research and Forecasting model(WRF) is cycled and evaluated for western North Pacific(WNP) typhoons of year 2016. Conventional in situ data, ...An ensemble Kalman filter(EnKF) combined with the Advanced Research Weather Research and Forecasting model(WRF) is cycled and evaluated for western North Pacific(WNP) typhoons of year 2016. Conventional in situ data, radiance observations, and tropical cyclone(TC) minimum sea level pressure(SLP) are assimilated every 6 h using an 80-member ensemble. For all TC categories, the 6-h ensemble priors from the WRF/EnKF system have an appropriate amount of variance for TC tracks but have insufficient variance for TC intensity. The 6-h ensemble priors from the WRF/EnKF system tend to overestimate the intensity for weak storms but underestimate the intensity for strong storms. The 5-d deterministic forecasts launched from the ensemble mean analyses of WRF/EnKF are compared to the NCEP and ECMWF operational control forecasts. Results show that the WRF/EnKF forecasts generally have larger track errors than the NCEP and ECMWF forecasts for all TC categories because the regional simulation cannot represent the large-scale environment better than the global simulation. The WRF/EnKF forecasts produce smaller intensity errors and biases than the NCEP and ECMWF forecasts for typhoons, but the opposite is true for tropical storms and severe tropical storms. The 5-d ensemble forecasts from the WRF/EnKF system for seven typhoon cases show appropriate variance for TC track and intensity with short forecast lead times but have insufficient spread with long forecast lead times. The WRF/EnKF system provides better ensemble forecasts and higher predictability for TC intensity than the NCEP and ECMWF ensemble forecasts.展开更多
The slag formation path is important for efficient dephosphorization in steelmaking processes. The phosphorus capacity and the melting properties of the slag are critical parameters for optimizing the slag formation p...The slag formation path is important for efficient dephosphorization in steelmaking processes. The phosphorus capacity and the melting properties of the slag are critical parameters for optimizing the slag formation path. Regarding these two factors, the phosphorus partition ratio was calculated using the regular solution model (RSM), whereas the liquidus diagrams of the slag systems were estimated using the FactSage thermodynamic package. A slag formation path that satisfies the different requirements of dephosphorization at different stages of dephosphorization in a converter was thus established through a combination of these two aspects. The composition of the initial slag was considered to be approximately 15wt%CaO-44wt% SiOz-41wt%FeO. During the dephosphorization process, a slag formation path that follows a high-iron route would facilitate efficient dephosphorization. The composition of the final dephosphorization slag should be approximately 53wt%CaO-25.Swt% SiO2-21.5wt%FeO. The composition of the final solid slag after dephosphorization is approximately 63.6wt%CaO-30.3wt%SiO2-6. 1wt%FeO.展开更多
The Minister’s Black Veil is one of the most classic short stories written by American romantic writer Nathaniel Hawthorne(1804-1864),From the perspective of literary pragmatics,this paper analyzes the language featu...The Minister’s Black Veil is one of the most classic short stories written by American romantic writer Nathaniel Hawthorne(1804-1864),From the perspective of literary pragmatics,this paper analyzes the language features of the novel,such as words and sentences,grammar,semantic ambiguity,rhetoric and conversational implicature based on cooperative principle,so as to explore the superb writing style and literary art of the novel,better understand and appreciate this literary work,and provide a new perspective and reference for the study of British and American literature Direction.展开更多
Relationship between precipitation strengthening and creep resistance improvement has been an impor-tant topic for the widespread applications of magnesium alloys.Generally,static precipitation strength-ening through ...Relationship between precipitation strengthening and creep resistance improvement has been an impor-tant topic for the widespread applications of magnesium alloys.Generally,static precipitation strength-ening through thermal stable precipitates would generate satisfactory creep resistance.However,an op-posite example is presented in this work and we propose that the size of precipitates plays a crucial role in controlling the operative creep mechanisms.In addition,the precipitate components along with their crystal structures in the crept Mg-4Al-3Sm-0.4Mn samples with/without pre-aging were thor-oughly studied using Cs aberration-corrected high-angle annular dark-field scanning transmission elec-tron microscopy(HAADF-STEM).Previous aging generates a large density of fine precipitates(<~5 nm)homogeneously distributing in Mg matrix and exhibiting satisfactory strengthening effect.However,the number density of precipitate strings consisting of several or even dozens of relatively coarse precipitates(~10 nm)was significantly decreased at the same time.As revealed in this work,the relatively coarse particles in Mg matrix are much more efficient than the fine precipitates in promoting dislocation climb.Therefore,the rate-controlling mechanisms are transferred from dislocation climb to dislocation slip after previous aging,thus leading to degradation of creep resistance.Moreover,there are mainly five types of precipitates/clusters,namelyβ"-(Al,Mg)3Sm,Al5Sm3,ordered Al-Sm cluster,ordered Al-Mn cluster and ordered/unordered AlMnSm clusters.The crystal structures of the former two precipitates were discussed and the formation mechanisms of the precipitates/clusters were revealed.展开更多
Thermal stable intermetallic particles are important for the heat resistance of magnesium(Mg)alloys.In this work,many lath-like particles formed in α-Mg grains of a Mg-8Gd-3Sm-0.7Al casting alloy when heat-treated at...Thermal stable intermetallic particles are important for the heat resistance of magnesium(Mg)alloys.In this work,many lath-like particles formed in α-Mg grains of a Mg-8Gd-3Sm-0.7Al casting alloy when heat-treated at 873 K.Atomic-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM) characterizations indicate that most of them are Mg-containing Al_(2)(Gd,Sm),with the atomic ratio of Mg:Al:(Gd,Sm) being ~1:1:1;a small part of them with relatively wider thickness are long-period stacking ordered(LPSO) phases simultaneously containing both 14H and 18R structures.Both followed common orientation relationships with Mg matrix as those reported in previous work.In addition,many Mg laths were observed in the primary blocky Al_(2)(Gd,Sm) phase at grain boundaries,where the atomic ratio of Al:(Gd,Sm) in the Al_(2)(Gd,Sm) matrix was 2:1.Finally,density functional theory(DFT) calculations illustrated the detail structure of the re-constructed Mg/Al_(2)RE interface and simultaneously deduced the underlying reason for the re-dissolution of the newly formed Mg-containing Al_(2)(Gd,Sm) plates in α-Mg matrix.展开更多
Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg...Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg-RE(rare earth)based alloys or even some new Mg-Li basedalloys[7-19].展开更多
Background:Hearing loss(HL)is becoming increasingly common and is more commonly caused by noise,ototoxic substances,or a combination of ototoxic factors.However,so far,few studies have examined the mechanism by which ...Background:Hearing loss(HL)is becoming increasingly common and is more commonly caused by noise,ototoxic substances,or a combination of ototoxic factors.However,so far,few studies have examined the mechanism by which compound factors cause HL.The only relevant study is about occupational ototoxic substances combined with environmental noise at 85-110 dB SPL.In this study,to address the shortcomings of existing research,we innovatively focused on HL induced by loud noise(impulse noise,>160 dB SPL)combined with common ototoxic drugs.The aim of this study was to establish and validate a mature animal model,and then to compare the characteristics of audiology,pathomorphology and molecular features,and to preliminarily predict pathogenesis in compound HL.Materials and Methods:We selected guinea pigs to construct in vivo HL model groups for different extents of exposure,including a blank control group,a single-drug group,a single-impulse noise group,and a compound group.The animal model of the mature compound HL group was established using gentamicin combined with impulse noise.We then performed audio-logical and pathological verification.We analyzed the auditory brainstem response(ABR),pathological morphology of the cochlea,and molecules(including important self-radicals,cytokines,and apoptosis signal trans-duction pathway proteins in the pathogenesis of drug-and noise-induced HL),compared the effect of different extents of exposure on HL,and preliminarily predict the pathogenic mechanism of compound HL.Results:Four groups of animal models were established successfully and verified by audiology and pathology.Regarding audiology,there were no sig-nificant differences in the ABR thresholds before exposure(p>0.05),but differences emerged among the groups after exposure.Notably,after 3,7,and 14 days of exposure,there were significant differences in the ABR thresholds between the compound group and both the drug and noise groups(p<0.01),and after 14 days,the HL of the compound group was much more severe(greater than the linear sum of single-factor HL group).Regarding the patho-morphology,compared with the control group,the cochleae were damaged to different degrees in the factor exposure groups.The drug group had the least severe HL,the noise group had serious HL(p<0.05),and the compound group had the most severe HL(p<0.01).The compound group's damage was greater than the linear sum of the single-factor group in many ways,such as the loss and damage of hair cells and cilia,disturbed morphology and arrangement of hair cells,protein metabolism,cell function,and structural defects on the epidermal plate(p<0.01).From a molecular perspective,the trend was similar to pathology and audiology,and the synergistic effect of ototoxic drugs and impulse noise significantly increased cytokine levels(IL-6,ICAM-1,8-OHDG,IL-1,and TNF-α),free radicals Malondialdehyde([MDA],▪OH,LPO,O•2ˉ),and the apoptosis signal transduction pathway protein.There were significant differences between the compound group and single-factor groups(p<0.05).Conclusion:Gentamicin,impulse noise,and compound factors were used to induce HL in animal models,which were verified by audiology and pathology,laying a foundation for future studies.After constructing the animal models,we found that 50 mg/kg of gentamicin for 10 days was a subinjury dose,and 50�impulse noise caused partial HL,but the two factors combined had a significant synergistic ototoxicity effect,which increased the level of oxidative stress and the waterfall response of inflammatory cytokines in the cochleae and enhanced the expression of apoptosis-related proteins,resulting in syn-ergistic pathomorphological and audiological injury.We preliminarily analyzed the pathogenic mechanism of compound HL,establishing the basis for further study of the mechanism,prevention,and treatment of this increasing global problem.展开更多
Background Somatic mutation contributes to clonal haematopoiesis of indeterminate potential(CHIP)is related to age and associated with a higher risk of stroke and atherosclerotic cardiovascular disease.Here,we investi...Background Somatic mutation contributes to clonal haematopoiesis of indeterminate potential(CHIP)is related to age and associated with a higher risk of stroke and atherosclerotic cardiovascular disease.Here,we investigated the prognostic significance of CHIP in a large first-ever acute ischaemic stroke(AIS)cohort and explored the underlying mechanisms.Methods We studied a prospective cohort of 6016 patients who had a first-ever AIS in China.Whole-genome sequencing was performed to identify CHIP.High-sensitivity C reactive protein(hs-CRP)levels above 3 mg/L at baseline were defined as hyperinflammation.Recurrent stroke during the 3-month follow-up was the primary outcome.Results Among the 6016 patients who had a first-ever AIS,with a median age was 62 years(IQR,54.0‒70.0),3.70%were identified as CHIP carriers.The most common mutations occurred in the DNMT3A(30.0%)and TET2(11.4%)genes.During a follow-up of 3 months,the presence of CHIP was associated with recurrent stroke(HR 1.62,95%CI 1.04 to 2.51,p=0.03),recurrent ischaemic stroke(HR 1.64,95%CI 1.04 to 2.58,p=0.03)and combined vascular events(HR 1.58,95%CI 1.02 to 2.44,p=0.04)after adjusting for hsCRP levels at baseline in patients who had a first-ever AIS.Subgroup analysis demonstrated that CHIP was only associated with recurrent stroke when patients under hyperinflammation(OR 3.10,95%CI 1.92 to 5.00,p<0.001)but not in those without hyperinflammation(OR 0.18,95%CI 0.03 to 1.04,p=0.06,Pinteraction=0.002).Conclusion Our results suggest that somatic mutations contributing to CHIP increase the risk of short-term recurrent stroke in patients who had a first-ever AIS.Hyperinflammation may be important in the relationship between CHIP and recurrent stroke.展开更多
To uncover the role of satellite cells(SCs)in paravertebral muscle development and aging,we constructed a single-nucleus transcriptomic atlas of mouse paravertebral muscle across seven timepoints spanning the embryo(d...To uncover the role of satellite cells(SCs)in paravertebral muscle development and aging,we constructed a single-nucleus transcriptomic atlas of mouse paravertebral muscle across seven timepoints spanning the embryo(day 16.5)to old(month 24)stages.Eight cell types,including SCs,fast muscle cells,and slow muscle cells,were identified.An energy metabolism-related gene set,TCA CYCLE IN SENESCENCE,was enriched in SCs.Forty-two skeletal muscle disease-related genes were highly expressed in SCs and exhibited similar expression patterns.Among them,Pdha1 was the core gene in the TCA CYCLE IN SENESCENCE;Pgam2,Sod1,and Suclg1 are transcription factors closely associated with skeletal muscle energy metabolism.Transcription factor enrichment analysis of the 42 genes revealed that Myod1 and Mef2a were also highly expressed in SCs,which regulated Pdha1 expression and were associated with skeletal muscle development.These findings hint that energy metabolism may be pivotal in SCs development and aging.Three ligand-receptor pairs of extracellular matrix(ECM)-receptor interactions,Lamc1-Dag1,Lama2-Dag1,and Hspg2-Dag1,may play a vital role in SCs interactions with slow/fast muscle cells and SCs self-renewal.Finally,we built the first database of a skeletal muscle single-cell transcriptome,the Musculoskeletal Cell Atlas(http://www.mskca.tech),which lists 630,040 skeletal muscle cells and provides interactive visualization,a useful resource for revealing skeletal muscle cellular heterogeneity during development and aging.Our study could provide new targets and ideas for developing drugs to inhibit skeletal muscle aging and treat skeletal muscle diseases.展开更多
The microstructures and tensile properties of Mg-6.0 Zn-0.6 Zr(ZK60) and ZK60 + 1.8 Gd(ZEK620(RE = Gd)) alloys extruded at 290, 305, 320, 340 and360 ℃ were investigated. The results indicate that Gd addition can refi...The microstructures and tensile properties of Mg-6.0 Zn-0.6 Zr(ZK60) and ZK60 + 1.8 Gd(ZEK620(RE = Gd)) alloys extruded at 290, 305, 320, 340 and360 ℃ were investigated. The results indicate that Gd addition can refine the microstructures of ZK60 alloy and the extrusion parameters such as the extrusion temperature will influence the tensile properties of both as-extruded ZK60 and ZEK620 alloys, although it is much slighter for ZK60 alloy. And the sensitivity is closely related to the textures developed during extrusion. In addition, Gd addition will also clearly improve the tensile strength at room temperature(24 ℃) and particularly at high temperatures(150 and 200 ℃), due to the much finer grains and smaller intermetallic particles. The highest strength is achieved in the as-extruded ZEK620 alloy with extrusion temperature of 320 ℃, with ultimate tensile strength(UTS) and tensile yield strength(TYS) of 405 and375 MPa, respectively, which are improved by approximately 9% and 11% than those of the as-extruded ZK60 alloy which owns the highest strength at extrusion temperature of 290 ℃.展开更多
The effect of Nd addition and the influence of extrusion processes on the microstructure and mechanical properties of Mg-6Zn-0.5Zr(ZK60) and Mg-6Zn-1.5Nd-0.5Zr(ZKNd602) alloys were investigated. Nd element can obv...The effect of Nd addition and the influence of extrusion processes on the microstructure and mechanical properties of Mg-6Zn-0.5Zr(ZK60) and Mg-6Zn-1.5Nd-0.5Zr(ZKNd602) alloys were investigated. Nd element can obviously refine the microstructure of both as-cast and asextruded Mg-Zn-Nd-Zr alloy. All of the extruded alloys exhibit a bimodal grain structure composed of equiaxedfine recrystallized(DRXed) grains and elongated coarse un DRXed grains. It is necessary to achieve high strength,particularly the yield strength, for ZKNd602 alloy, when it is extruded with a lower extrusion temperature, a suitable extrusion ratio and a relatively lower extrusion ram speed. In this study, the ultimate tensile strength(UTS),yield strength(YS) and elongation(El) of the extruded ZKNd602 alloy were 421 MPa, 402 MPa and 6.7 %,respectively, with extrusion temperature of 290 °C, extrusion ratio of 18:1 and a ram speed of approximate0.4 mm·s^(-1). Meanwhile, the extrusion process has obvious effects on the room-temperature properties but weak effects on the high-temperature properties.展开更多
Parkinson's disease(PD)is a neurodegenerative disease,leading to the impairment of movement execution.PD pathogenesis has been largely investigated,either limited to bulk transcriptomic levels or at certain cell t...Parkinson's disease(PD)is a neurodegenerative disease,leading to the impairment of movement execution.PD pathogenesis has been largely investigated,either limited to bulk transcriptomic levels or at certain cell types,which failed to capture the cellular heterogeneity and intrinsic interplays among distinct cell types.Here,we report the application of single-nucleus RNA-seq on midbrain,striatum,and cerebellum of theα-syn-A53 T mouse,a well-established PD mouse model,and matched controls,generating the first single cell transcriptomic atlas for the PD model mouse brain composed of 46,174 individual cells.Additionally,we comprehensively depicte the dysfunctions in PD pathology,covering the elevation of NF-k B activity,the alteration of ion channel components,the perturbation of protein homeostasis network,and the dysregulation of glutamatergic signaling.Notably,we identify a variety of cell types closely associated with PD risk genes.Taken together,our study provides valuable resources to systematically dissect the molecular mechanism of PD pathogenesis at the single-cell resolution,which facilitates the development of novel approaches for diagnosis and therapies against PD.展开更多
Perovskite nanocrystals (NCs) have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluore...Perovskite nanocrystals (NCs) have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluorescence microscopy. Here, we determine the one-photon linear absorption cross section of two kinds of blue-emitting perovskite NCs, i.e., CsPbCl3 and CsPb(C10.53Br0.47)3, by utilizing femtosecond transient absorption spectroscopy. The wavelength-dependent nonlinear refraction and two-photon absorption have been measured at wavelengths from 620 to 720 nm by performing Z-scan measurements. The nonlinear optical responses of CsPb(C10.53Br0.47)3 are much more pronounced than those of CsPbCl3 due to the larger structural destahilization of the former.展开更多
In this work,one kind of typeⅡZnSe/CdS/ZnS core/shell/shell nanocrystals(NCs)is synthesized,and their linear and nonlinear photophysical properties are investigated.Through measurements of the temperaturedependent ph...In this work,one kind of typeⅡZnSe/CdS/ZnS core/shell/shell nanocrystals(NCs)is synthesized,and their linear and nonlinear photophysical properties are investigated.Through measurements of the temperaturedependent photoluminescence spectra of NCs,their excitonic properties,including the coefficient of the bandgap change,coupling strength of the exciton acoustic phonons,exciton longitudinal optical(LO)phonons,and LO–phonon energy are revealed.Femtosecond transient absorption spectroscopy was employed to obtain insight into ultrafast processes occurring at the interface of ZnSe and CdS,such as those involving the injection of photoinduced electrons into the CdS shell,interfacial state bleaching,and charge separation time.At the end,their multiphoton absorption spectra were determined by using the z-scan technique,which yielded a maximum twophoton absorption cross section of 3717 GM at 820 nm and three-photon absorption cross section up to 3.9×10^-77cm^6·s^2·photon^-2at 1220 nm,respectively.The photophysical properties presented here may be important for exploiting their relevant applications in optoelectronic devices and deep-tissue bioimaging.展开更多
The brain of the domestic pig(Sus scrofa domesticus)has drawn considerable attention due to its high similarities to that of humans.However,the cellular compositions of the pig brain(PB)remain elusive.Here we investig...The brain of the domestic pig(Sus scrofa domesticus)has drawn considerable attention due to its high similarities to that of humans.However,the cellular compositions of the pig brain(PB)remain elusive.Here we investigated the single-nucleus transcriptomic profiles of five regions of the PB(frontal lobe,parietal lobe,temporal lobe,occipital lobe,and hypothalamus)and identified 21 cell subpopulations.The cross-species comparison of mouse and pig hypothalamus revealed the shared and specific gene expression patterns at the single-cell resolution.Furthermore,we identified cell types and molecular pathways closely associated with neurological disorders,bridging the gap between gene mutations and pathogenesis.We reported,to our knowledge,the first single-cell atlas of domestic pig cerebral cortex and hypothalamus combined with a comprehensive analysis across species,providing extensive resources for future research regarding neural science,evolutionary developmental biology,and regenerative medicine.展开更多
Importance:There are a variety of musculoskeletal malformations and injuries that can occur in newborns.These can be a significant cause of perinatal death or a reason for miscarriage and can lead to long-term functio...Importance:There are a variety of musculoskeletal malformations and injuries that can occur in newborns.These can be a significant cause of perinatal death or a reason for miscarriage and can lead to long-term functional issues if not managed appropriately.There is no systematic and well-established screening program for neonatal musculoskeletal malformations and injuries in China now.Objective:To report the incidence and types of congenital musculoskeletal malformations in two hospitals in Shenzhen City,to explore and discuss the details of the screening procedure and improve future prevention and treatment.Methods:From October 2013 to May 2014,2564 one-day-old newborns were screened by a pediatric orthopedic physical examination,in combination with ultrasonography when required,and the incidence and variety of diseases were recorded statistically.Results:Among 2564 screened newborns,the following musculoskeletal conditions were identified:congenital muscular torticollis(CMT)(seven cases,0.27%),hip subluxation(four cases,0.16%),hip dysplasia(47 cases,1.83%),congenital talipes equinovarus(CTEV)(two cases,0.08%),congenital talipes calcaneovalgus(15 cases,0.58%),polydactyly(nine cases,0.35%),syndactyly(one case,0.04%),and spinal hemivertebra(one case,0.04%).Additionally,there were five(0.19%)neonates with birth injuries.Interpretation:It is feasible to carry out neonatal screening and identification of musculoskeletal malformations and birth injuries in China.This is helpful as timely detection and early intervention for many of these conditions can avoid permanent functional impairment in these children.展开更多
Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys.In this work,interfacial precipitation in{1012}twin boundaries(TBs)of a cold-stamped Mg-12Gd-1.2Zn-0.4Zr alloy was i...Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys.In this work,interfacial precipitation in{1012}twin boundaries(TBs)of a cold-stamped Mg-12Gd-1.2Zn-0.4Zr alloy was investigated using atomic-resolution high-angle annular dark-field scanning transmission electron microscopy.Extended periodic segregation of Gd+Zn atoms in the~86.2°{1012}TBs with basal-prismatic facets and in the symmetric tilting TBs(obviously>86.2°)frequently occurred,resulted in the formation of new interfacial phases,namelyβ_(TB)’having a monoclinic structure in the TBs with two segregation layers andβ_(TB) having a tetragonal structure in the TBs with three or more segregation layers.The formation ofβ_(TB) clearly accelerates peak-aging and improves the alloy’s strength.展开更多
基金financially supported by the Scientific and Technological Developing Scheme of Jilin Province under grants no.20220402012GHthe National Natural Science Foundation of China under grants no.U21A20323+3 种基金the Capital Construction Fund within the Budget of Jilin Province no.2021C038-1the Special high-tech industrialization project of science and technology cooperation between Jilin Province and Chinese Academy of Sciences under grant no.2021SYHZ0043 and 2022SYHZ0038the Major science and technology projects of Jilin Province and Changchun City under grant no.20210301024GXthe Project for Jilin provincial department of education under grant no.JJKH20220760KJ。
文摘This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal(I-phase)precipitates.Although exhibiting traditional basal texture,it owns an exceptional CYS/TYS as high as~1.17.Electron back-scattered diffraction(EBSD)and transmission electron microscopy(TEM)examinations indicate pyramidal and prismatic dislocations plus tensile twinning being activated after immediate yielding in compression while basal and non-basal dislocations in tension.I-phase particles transferred the concentrated stress by self-twinning to provide the driving force for tensile twin initiating in neighboring grains,thereby significantly increasing the critical resolved shear stress of tensile twinning to possibly the level of pyramidal slip,finally leading to the dominance of pyramidal slip plus tensile twinning in texture grains.This results in a higher contribution on yield strength by~55 MPa in compression than in tension,which reasonably agrees with the experimental yield strength difference(~38 MPa).It can be concluded that I-phase particles influence deformation modes in tension and in compression,finally result in reversed yield strength asymmetry.
基金supported by the National Natural Science Foundation of China under grants no.51701200 and 11804030the Scientific and Technological Developing Scheme of Jilin Province under grants no.20200801048GHthe Project for Jilin Provincial Department of Education under grant no.JJKH20190583KJ。
文摘Components and crystal structures of the intermetallic phases in a gravity die-cast Mg-6.0Zn-1.5Nd-0.5Zr(wt%)alloy were investigated using transmission electron microscopy.The results indicate that this alloy has multiple intermetallic phases and various inner faults.Totally,six eutectoid intermetallic phases,namely W(Mg Nd Zn_(3)),T(Mg_(39)Zn_(55)Nd_(6)),(Mg,Zr)Zn_(2),Z(Mg_(28)Zn_(65)Nd_(7)),H_(2)(Mg_(15)Zn_(70)Nd_(15)),and H1(Mg_(24)Zn_(64)Nd_(11)),were simultaneously observed at grain boundaries,and six precipitates(Z,Mg_(7)Zn_(3),T,Mg_(4)Zn_(7),β_(1)-Mg Zn_(2) and β_(2)-Mg Zn_(2))were found inα-Mg grains.Furthermore,faults like sub-grain boundaries,orientation domains(coherent with the same matching plane but with different orientations),stacking faults and twins were observed in the eutectoid intermetallic phases.Finally,some new orientation relationships between the known intermetallic phases were revealed.This paper can provide new insight into alloy design for Mg-Zn-RE(RE:rare earth)based alloys.
基金JSPS KAKENHI for Scientific Research on Innovative Areas“Materials Science of a Mille-feuille Structure(Grant Numbers JP18H05475,JP18H05479)”the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(RERU2020012)+1 种基金“Nanotechnology Platform”of the MEXT,JapanGrant-in-Aid for JSPS Fellows(JP19F19775)。
文摘The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically investigated.In the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morphologies are identified as Mg_(3)Sm phase. In addition to Mg_(3)RE phase, Mg_(5)RE phase originated from Gd addition is observed in Gd-modified alloys. It should be noted that the lattice parameters of all the observed intermetallic compounds are significantly reduced by Zn segregation. The segregation behavior of Zn in Mg_(3)Sm phase is inhibited to some extent by Gd addition due to the electronegativity difference between Sm/Gd and Zn elements. In addition, the increased Gd content effectively leads to much more accumulation of solute atoms in front of the liquid-solid interface during solidification, which can prominently promote nucleation in liquid region and then refine grains. The tensile yield stress of the present alloys is thus improved with increasing Gd addition. Finally, Gd-modified alloys exhibit significantly age-hardening effect, which can be mainly attributed to the high-volume fraction and high density nano-scale precipitates.
基金jointly sponsored by the National Key R&D Program of China through Grant No. 2017YFC1501603the National Natural Science Foundation of China through Grant Nos. 41675052 and 41775057。
文摘An ensemble Kalman filter(EnKF) combined with the Advanced Research Weather Research and Forecasting model(WRF) is cycled and evaluated for western North Pacific(WNP) typhoons of year 2016. Conventional in situ data, radiance observations, and tropical cyclone(TC) minimum sea level pressure(SLP) are assimilated every 6 h using an 80-member ensemble. For all TC categories, the 6-h ensemble priors from the WRF/EnKF system have an appropriate amount of variance for TC tracks but have insufficient variance for TC intensity. The 6-h ensemble priors from the WRF/EnKF system tend to overestimate the intensity for weak storms but underestimate the intensity for strong storms. The 5-d deterministic forecasts launched from the ensemble mean analyses of WRF/EnKF are compared to the NCEP and ECMWF operational control forecasts. Results show that the WRF/EnKF forecasts generally have larger track errors than the NCEP and ECMWF forecasts for all TC categories because the regional simulation cannot represent the large-scale environment better than the global simulation. The WRF/EnKF forecasts produce smaller intensity errors and biases than the NCEP and ECMWF forecasts for typhoons, but the opposite is true for tropical storms and severe tropical storms. The 5-d ensemble forecasts from the WRF/EnKF system for seven typhoon cases show appropriate variance for TC track and intensity with short forecast lead times but have insufficient spread with long forecast lead times. The WRF/EnKF system provides better ensemble forecasts and higher predictability for TC intensity than the NCEP and ECMWF ensemble forecasts.
基金partially supported by the Fundamental Research Funds for the Central Universities (No. CDJZR 14130001)
文摘The slag formation path is important for efficient dephosphorization in steelmaking processes. The phosphorus capacity and the melting properties of the slag are critical parameters for optimizing the slag formation path. Regarding these two factors, the phosphorus partition ratio was calculated using the regular solution model (RSM), whereas the liquidus diagrams of the slag systems were estimated using the FactSage thermodynamic package. A slag formation path that satisfies the different requirements of dephosphorization at different stages of dephosphorization in a converter was thus established through a combination of these two aspects. The composition of the initial slag was considered to be approximately 15wt%CaO-44wt% SiOz-41wt%FeO. During the dephosphorization process, a slag formation path that follows a high-iron route would facilitate efficient dephosphorization. The composition of the final dephosphorization slag should be approximately 53wt%CaO-25.Swt% SiO2-21.5wt%FeO. The composition of the final solid slag after dephosphorization is approximately 63.6wt%CaO-30.3wt%SiO2-6. 1wt%FeO.
文摘The Minister’s Black Veil is one of the most classic short stories written by American romantic writer Nathaniel Hawthorne(1804-1864),From the perspective of literary pragmatics,this paper analyzes the language features of the novel,such as words and sentences,grammar,semantic ambiguity,rhetoric and conversational implicature based on cooperative principle,so as to explore the superb writing style and literary art of the novel,better understand and appreciate this literary work,and provide a new perspective and reference for the study of British and American literature Direction.
基金Chinese Academy of Sciences Youth Innovation Promotion Association(No.2023234)Scientific and Technological Developing Scheme of Jilin Province(No.20220402012GH)+2 种基金National Natural Science Foundation of China(No.U21A20323)Capital Construction Fund within the Budget of Jilin Province(No.2023C044-2)Major science and technology projects of Jilin Province and Changchun City(No.20220301026GX),the Special high-tech。
文摘Relationship between precipitation strengthening and creep resistance improvement has been an impor-tant topic for the widespread applications of magnesium alloys.Generally,static precipitation strength-ening through thermal stable precipitates would generate satisfactory creep resistance.However,an op-posite example is presented in this work and we propose that the size of precipitates plays a crucial role in controlling the operative creep mechanisms.In addition,the precipitate components along with their crystal structures in the crept Mg-4Al-3Sm-0.4Mn samples with/without pre-aging were thor-oughly studied using Cs aberration-corrected high-angle annular dark-field scanning transmission elec-tron microscopy(HAADF-STEM).Previous aging generates a large density of fine precipitates(<~5 nm)homogeneously distributing in Mg matrix and exhibiting satisfactory strengthening effect.However,the number density of precipitate strings consisting of several or even dozens of relatively coarse precipitates(~10 nm)was significantly decreased at the same time.As revealed in this work,the relatively coarse particles in Mg matrix are much more efficient than the fine precipitates in promoting dislocation climb.Therefore,the rate-controlling mechanisms are transferred from dislocation climb to dislocation slip after previous aging,thus leading to degradation of creep resistance.Moreover,there are mainly five types of precipitates/clusters,namelyβ"-(Al,Mg)3Sm,Al5Sm3,ordered Al-Sm cluster,ordered Al-Mn cluster and ordered/unordered AlMnSm clusters.The crystal structures of the former two precipitates were discussed and the formation mechanisms of the precipitates/clusters were revealed.
基金financially supported by the Scientific and Technological Developing Scheme of Jilin Province(Nos.YDZJ202301ZYTS538 and 20220101239JC)the Chinese Academy of Sciences Youth Innovation Promotion Association (No.2023234)+3 种基金the National Natural Science Foundation of China (No.U21A20323)the Scientific and Technological Developing Scheme of Jilin Province (No.SKL202302038)the Major Scientific and Technological Projects of Hebei Province (No.23291001Z)the Scientific and Technology Project of Hanjiang District。
文摘Thermal stable intermetallic particles are important for the heat resistance of magnesium(Mg)alloys.In this work,many lath-like particles formed in α-Mg grains of a Mg-8Gd-3Sm-0.7Al casting alloy when heat-treated at 873 K.Atomic-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM) characterizations indicate that most of them are Mg-containing Al_(2)(Gd,Sm),with the atomic ratio of Mg:Al:(Gd,Sm) being ~1:1:1;a small part of them with relatively wider thickness are long-period stacking ordered(LPSO) phases simultaneously containing both 14H and 18R structures.Both followed common orientation relationships with Mg matrix as those reported in previous work.In addition,many Mg laths were observed in the primary blocky Al_(2)(Gd,Sm) phase at grain boundaries,where the atomic ratio of Al:(Gd,Sm) in the Al_(2)(Gd,Sm) matrix was 2:1.Finally,density functional theory(DFT) calculations illustrated the detail structure of the re-constructed Mg/Al_(2)RE interface and simultaneously deduced the underlying reason for the re-dissolution of the newly formed Mg-containing Al_(2)(Gd,Sm) plates in α-Mg matrix.
基金financially supported by the Projects for Science and Technology of Jilin Province(Nos.20210402064GH and 20220402012GH)the National Natural Science Foundation of China(No.U21A20323)+3 种基金the Capital Construction Fund within the Budget of Jilin Province(No.2023C044-2)the Special High-Tech Industrialization Project of Science and Technology Cooperation between Jilin Province and Chinese Academy of Sciences(No.2021SYHZ0043)the Major science and technology projects of Jilin Province and Changchun City(No.20210301024GX)the Project for Jilin provincial department of education(No.JJKH20220760KJ)。
文摘Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg-RE(rare earth)based alloys or even some new Mg-Li basedalloys[7-19].
基金National Natural Science Foundation of China,Grant/Award Number:81470700Beijing Municipal Natural Science Foundation,Grant/Award Number:7222185+1 种基金Key R&D program of Ministry of Science and Technology,Grant/Award Number:2022YFC2402704National Key Research and Development Program of China,Grant/Award Numbers:2020YFC2004001,2020YFC2005203。
文摘Background:Hearing loss(HL)is becoming increasingly common and is more commonly caused by noise,ototoxic substances,or a combination of ototoxic factors.However,so far,few studies have examined the mechanism by which compound factors cause HL.The only relevant study is about occupational ototoxic substances combined with environmental noise at 85-110 dB SPL.In this study,to address the shortcomings of existing research,we innovatively focused on HL induced by loud noise(impulse noise,>160 dB SPL)combined with common ototoxic drugs.The aim of this study was to establish and validate a mature animal model,and then to compare the characteristics of audiology,pathomorphology and molecular features,and to preliminarily predict pathogenesis in compound HL.Materials and Methods:We selected guinea pigs to construct in vivo HL model groups for different extents of exposure,including a blank control group,a single-drug group,a single-impulse noise group,and a compound group.The animal model of the mature compound HL group was established using gentamicin combined with impulse noise.We then performed audio-logical and pathological verification.We analyzed the auditory brainstem response(ABR),pathological morphology of the cochlea,and molecules(including important self-radicals,cytokines,and apoptosis signal trans-duction pathway proteins in the pathogenesis of drug-and noise-induced HL),compared the effect of different extents of exposure on HL,and preliminarily predict the pathogenic mechanism of compound HL.Results:Four groups of animal models were established successfully and verified by audiology and pathology.Regarding audiology,there were no sig-nificant differences in the ABR thresholds before exposure(p>0.05),but differences emerged among the groups after exposure.Notably,after 3,7,and 14 days of exposure,there were significant differences in the ABR thresholds between the compound group and both the drug and noise groups(p<0.01),and after 14 days,the HL of the compound group was much more severe(greater than the linear sum of single-factor HL group).Regarding the patho-morphology,compared with the control group,the cochleae were damaged to different degrees in the factor exposure groups.The drug group had the least severe HL,the noise group had serious HL(p<0.05),and the compound group had the most severe HL(p<0.01).The compound group's damage was greater than the linear sum of the single-factor group in many ways,such as the loss and damage of hair cells and cilia,disturbed morphology and arrangement of hair cells,protein metabolism,cell function,and structural defects on the epidermal plate(p<0.01).From a molecular perspective,the trend was similar to pathology and audiology,and the synergistic effect of ototoxic drugs and impulse noise significantly increased cytokine levels(IL-6,ICAM-1,8-OHDG,IL-1,and TNF-α),free radicals Malondialdehyde([MDA],▪OH,LPO,O•2ˉ),and the apoptosis signal transduction pathway protein.There were significant differences between the compound group and single-factor groups(p<0.05).Conclusion:Gentamicin,impulse noise,and compound factors were used to induce HL in animal models,which were verified by audiology and pathology,laying a foundation for future studies.After constructing the animal models,we found that 50 mg/kg of gentamicin for 10 days was a subinjury dose,and 50�impulse noise caused partial HL,but the two factors combined had a significant synergistic ototoxicity effect,which increased the level of oxidative stress and the waterfall response of inflammatory cytokines in the cochleae and enhanced the expression of apoptosis-related proteins,resulting in syn-ergistic pathomorphological and audiological injury.We preliminarily analyzed the pathogenic mechanism of compound HL,establishing the basis for further study of the mechanism,prevention,and treatment of this increasing global problem.
基金supported by grants from National Natural Science Foundation of China(grant number 82171270,81870905,U20A20358)Natural Science Foundation of Beijing(Z200016)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2019-I2M 5-029).
文摘Background Somatic mutation contributes to clonal haematopoiesis of indeterminate potential(CHIP)is related to age and associated with a higher risk of stroke and atherosclerotic cardiovascular disease.Here,we investigated the prognostic significance of CHIP in a large first-ever acute ischaemic stroke(AIS)cohort and explored the underlying mechanisms.Methods We studied a prospective cohort of 6016 patients who had a first-ever AIS in China.Whole-genome sequencing was performed to identify CHIP.High-sensitivity C reactive protein(hs-CRP)levels above 3 mg/L at baseline were defined as hyperinflammation.Recurrent stroke during the 3-month follow-up was the primary outcome.Results Among the 6016 patients who had a first-ever AIS,with a median age was 62 years(IQR,54.0‒70.0),3.70%were identified as CHIP carriers.The most common mutations occurred in the DNMT3A(30.0%)and TET2(11.4%)genes.During a follow-up of 3 months,the presence of CHIP was associated with recurrent stroke(HR 1.62,95%CI 1.04 to 2.51,p=0.03),recurrent ischaemic stroke(HR 1.64,95%CI 1.04 to 2.58,p=0.03)and combined vascular events(HR 1.58,95%CI 1.02 to 2.44,p=0.04)after adjusting for hsCRP levels at baseline in patients who had a first-ever AIS.Subgroup analysis demonstrated that CHIP was only associated with recurrent stroke when patients under hyperinflammation(OR 3.10,95%CI 1.92 to 5.00,p<0.001)but not in those without hyperinflammation(OR 0.18,95%CI 0.03 to 1.04,p=0.06,Pinteraction=0.002).Conclusion Our results suggest that somatic mutations contributing to CHIP increase the risk of short-term recurrent stroke in patients who had a first-ever AIS.Hyperinflammation may be important in the relationship between CHIP and recurrent stroke.
基金supported by the Shenzhen Fundamental Research Program,China(No.JCYJ20180306173518936)Sanming Project of Medicine in Shenzhen,China(No.SZSM201612055)+1 种基金HKU-SZH Fund for Shenzhen Key Medical Discipline(China)(No.SZXK2020084)China National GeneBank(CNGB).
文摘To uncover the role of satellite cells(SCs)in paravertebral muscle development and aging,we constructed a single-nucleus transcriptomic atlas of mouse paravertebral muscle across seven timepoints spanning the embryo(day 16.5)to old(month 24)stages.Eight cell types,including SCs,fast muscle cells,and slow muscle cells,were identified.An energy metabolism-related gene set,TCA CYCLE IN SENESCENCE,was enriched in SCs.Forty-two skeletal muscle disease-related genes were highly expressed in SCs and exhibited similar expression patterns.Among them,Pdha1 was the core gene in the TCA CYCLE IN SENESCENCE;Pgam2,Sod1,and Suclg1 are transcription factors closely associated with skeletal muscle energy metabolism.Transcription factor enrichment analysis of the 42 genes revealed that Myod1 and Mef2a were also highly expressed in SCs,which regulated Pdha1 expression and were associated with skeletal muscle development.These findings hint that energy metabolism may be pivotal in SCs development and aging.Three ligand-receptor pairs of extracellular matrix(ECM)-receptor interactions,Lamc1-Dag1,Lama2-Dag1,and Hspg2-Dag1,may play a vital role in SCs interactions with slow/fast muscle cells and SCs self-renewal.Finally,we built the first database of a skeletal muscle single-cell transcriptome,the Musculoskeletal Cell Atlas(http://www.mskca.tech),which lists 630,040 skeletal muscle cells and provides interactive visualization,a useful resource for revealing skeletal muscle cellular heterogeneity during development and aging.Our study could provide new targets and ideas for developing drugs to inhibit skeletal muscle aging and treat skeletal muscle diseases.
基金financially supported by the National Natural Science Foundation of China (No. 21521092)the National Science and Technology Project (No. 2015DFH50210)the Project of Science and Technology Department of Jilin Province (Nos.20140306003GX,201602011004GX, 2016SYHZ0006 and 20170414001GH)
文摘The microstructures and tensile properties of Mg-6.0 Zn-0.6 Zr(ZK60) and ZK60 + 1.8 Gd(ZEK620(RE = Gd)) alloys extruded at 290, 305, 320, 340 and360 ℃ were investigated. The results indicate that Gd addition can refine the microstructures of ZK60 alloy and the extrusion parameters such as the extrusion temperature will influence the tensile properties of both as-extruded ZK60 and ZEK620 alloys, although it is much slighter for ZK60 alloy. And the sensitivity is closely related to the textures developed during extrusion. In addition, Gd addition will also clearly improve the tensile strength at room temperature(24 ℃) and particularly at high temperatures(150 and 200 ℃), due to the much finer grains and smaller intermetallic particles. The highest strength is achieved in the as-extruded ZEK620 alloy with extrusion temperature of 320 ℃, with ultimate tensile strength(UTS) and tensile yield strength(TYS) of 405 and375 MPa, respectively, which are improved by approximately 9% and 11% than those of the as-extruded ZK60 alloy which owns the highest strength at extrusion temperature of 290 ℃.
基金financially supported by the National Natural Science Foundation of China (No. 21521092)the Project of National Science and Technology Program (Nos. 20140306 003GX, 20130305008GX, 20130305009GX, 2015DFH50210, 2016SY HZ0006, 2014-GX-216A, and 20160623029TC)
文摘The effect of Nd addition and the influence of extrusion processes on the microstructure and mechanical properties of Mg-6Zn-0.5Zr(ZK60) and Mg-6Zn-1.5Nd-0.5Zr(ZKNd602) alloys were investigated. Nd element can obviously refine the microstructure of both as-cast and asextruded Mg-Zn-Nd-Zr alloy. All of the extruded alloys exhibit a bimodal grain structure composed of equiaxedfine recrystallized(DRXed) grains and elongated coarse un DRXed grains. It is necessary to achieve high strength,particularly the yield strength, for ZKNd602 alloy, when it is extruded with a lower extrusion temperature, a suitable extrusion ratio and a relatively lower extrusion ram speed. In this study, the ultimate tensile strength(UTS),yield strength(YS) and elongation(El) of the extruded ZKNd602 alloy were 421 MPa, 402 MPa and 6.7 %,respectively, with extrusion temperature of 290 °C, extrusion ratio of 18:1 and a ram speed of approximate0.4 mm·s^(-1). Meanwhile, the extrusion process has obvious effects on the room-temperature properties but weak effects on the high-temperature properties.
基金supported by the National Natural Science Foundation of China(31702074 and 31872309)Sanming Project of Medicine in Shenzhen(SZSM202011012)Science,Technology and Innovation Commission of Shenzhen Municipality(JCYJ20170412153100794)。
文摘Parkinson's disease(PD)is a neurodegenerative disease,leading to the impairment of movement execution.PD pathogenesis has been largely investigated,either limited to bulk transcriptomic levels or at certain cell types,which failed to capture the cellular heterogeneity and intrinsic interplays among distinct cell types.Here,we report the application of single-nucleus RNA-seq on midbrain,striatum,and cerebellum of theα-syn-A53 T mouse,a well-established PD mouse model,and matched controls,generating the first single cell transcriptomic atlas for the PD model mouse brain composed of 46,174 individual cells.Additionally,we comprehensively depicte the dysfunctions in PD pathology,covering the elevation of NF-k B activity,the alteration of ion channel components,the perturbation of protein homeostasis network,and the dysregulation of glutamatergic signaling.Notably,we identify a variety of cell types closely associated with PD risk genes.Taken together,our study provides valuable resources to systematically dissect the molecular mechanism of PD pathogenesis at the single-cell resolution,which facilitates the development of novel approaches for diagnosis and therapies against PD.
基金Shenzhen Basic Research Project of Science and Technology(JCYJ2015032414171163,JCYJ20170302142433007)National Natural Science Foundation of China(NSFC)(11404092,11404219,11574130)
文摘Perovskite nanocrystals (NCs) have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluorescence microscopy. Here, we determine the one-photon linear absorption cross section of two kinds of blue-emitting perovskite NCs, i.e., CsPbCl3 and CsPb(C10.53Br0.47)3, by utilizing femtosecond transient absorption spectroscopy. The wavelength-dependent nonlinear refraction and two-photon absorption have been measured at wavelengths from 620 to 720 nm by performing Z-scan measurements. The nonlinear optical responses of CsPb(C10.53Br0.47)3 are much more pronounced than those of CsPbCl3 due to the larger structural destahilization of the former.
基金Natural Science Foundation of Guangdong Province(2018A030310637,2019A1515012094)Department of Education of Guangdong Province(2018KTSCX19)。
文摘In this work,one kind of typeⅡZnSe/CdS/ZnS core/shell/shell nanocrystals(NCs)is synthesized,and their linear and nonlinear photophysical properties are investigated.Through measurements of the temperaturedependent photoluminescence spectra of NCs,their excitonic properties,including the coefficient of the bandgap change,coupling strength of the exciton acoustic phonons,exciton longitudinal optical(LO)phonons,and LO–phonon energy are revealed.Femtosecond transient absorption spectroscopy was employed to obtain insight into ultrafast processes occurring at the interface of ZnSe and CdS,such as those involving the injection of photoinduced electrons into the CdS shell,interfacial state bleaching,and charge separation time.At the end,their multiphoton absorption spectra were determined by using the z-scan technique,which yielded a maximum twophoton absorption cross section of 3717 GM at 820 nm and three-photon absorption cross section up to 3.9×10^-77cm^6·s^2·photon^-2at 1220 nm,respectively.The photophysical properties presented here may be important for exploiting their relevant applications in optoelectronic devices and deep-tissue bioimaging.
基金the China Postdoctoral Science Foundation(2017M622795)the Science,Technology and Innovation Commission of Shenzhen Municipality(JCYJ20180507183628543)the Fundamental Research Funds for the Central Universities(2662018PY025 and 2662017PY105)。
文摘The brain of the domestic pig(Sus scrofa domesticus)has drawn considerable attention due to its high similarities to that of humans.However,the cellular compositions of the pig brain(PB)remain elusive.Here we investigated the single-nucleus transcriptomic profiles of five regions of the PB(frontal lobe,parietal lobe,temporal lobe,occipital lobe,and hypothalamus)and identified 21 cell subpopulations.The cross-species comparison of mouse and pig hypothalamus revealed the shared and specific gene expression patterns at the single-cell resolution.Furthermore,we identified cell types and molecular pathways closely associated with neurological disorders,bridging the gap between gene mutations and pathogenesis.We reported,to our knowledge,the first single-cell atlas of domestic pig cerebral cortex and hypothalamus combined with a comprehensive analysis across species,providing extensive resources for future research regarding neural science,evolutionary developmental biology,and regenerative medicine.
基金Sanming Project of Medicine in Shenzhen(Grant/Award Number:SZSM202011012)Shenzhen Fund for Guangdong Provincial High-level Clinical Key specialties(Grant/Award Number:No.SZXK035)Shenzhen Innovation Science and Technology Committee(Grant/Award Number:JCYJ20180228175358223)。
文摘Importance:There are a variety of musculoskeletal malformations and injuries that can occur in newborns.These can be a significant cause of perinatal death or a reason for miscarriage and can lead to long-term functional issues if not managed appropriately.There is no systematic and well-established screening program for neonatal musculoskeletal malformations and injuries in China now.Objective:To report the incidence and types of congenital musculoskeletal malformations in two hospitals in Shenzhen City,to explore and discuss the details of the screening procedure and improve future prevention and treatment.Methods:From October 2013 to May 2014,2564 one-day-old newborns were screened by a pediatric orthopedic physical examination,in combination with ultrasonography when required,and the incidence and variety of diseases were recorded statistically.Results:Among 2564 screened newborns,the following musculoskeletal conditions were identified:congenital muscular torticollis(CMT)(seven cases,0.27%),hip subluxation(four cases,0.16%),hip dysplasia(47 cases,1.83%),congenital talipes equinovarus(CTEV)(two cases,0.08%),congenital talipes calcaneovalgus(15 cases,0.58%),polydactyly(nine cases,0.35%),syndactyly(one case,0.04%),and spinal hemivertebra(one case,0.04%).Additionally,there were five(0.19%)neonates with birth injuries.Interpretation:It is feasible to carry out neonatal screening and identification of musculoskeletal malformations and birth injuries in China.This is helpful as timely detection and early intervention for many of these conditions can avoid permanent functional impairment in these children.
基金financially supported by the Scientific and Technological Developing Scheme of Jilin Province under grants No.YDZJ202102CXJD012,20200801048GH,20200602021ZPthe Capital Construction Founds of Jilin Province with Innovation Capacity Building under grants No.2021C038-1。
文摘Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys.In this work,interfacial precipitation in{1012}twin boundaries(TBs)of a cold-stamped Mg-12Gd-1.2Zn-0.4Zr alloy was investigated using atomic-resolution high-angle annular dark-field scanning transmission electron microscopy.Extended periodic segregation of Gd+Zn atoms in the~86.2°{1012}TBs with basal-prismatic facets and in the symmetric tilting TBs(obviously>86.2°)frequently occurred,resulted in the formation of new interfacial phases,namelyβ_(TB)’having a monoclinic structure in the TBs with two segregation layers andβ_(TB) having a tetragonal structure in the TBs with three or more segregation layers.The formation ofβ_(TB) clearly accelerates peak-aging and improves the alloy’s strength.