We performed the pressure calibration to 12 GPa for 14/6 type(octahedron edge length/WC truncated edge length,in mm) cell assembly in DS 6 × 1400 multi-anvil apparatus by using the phase transitions in Bi(Ⅰ-Ⅱ2....We performed the pressure calibration to 12 GPa for 14/6 type(octahedron edge length/WC truncated edge length,in mm) cell assembly in DS 6 × 1400 multi-anvil apparatus by using the phase transitions in Bi(Ⅰ-Ⅱ2.55 GPa,Ⅲ-Ⅴ 7.67 GPa) and ZnTe(LPP-HPP Ⅰ 9.6 GPa,HPP Ⅰ-Ⅱ 12.0 GPa).As verification and application,sound velocity measurements on poly crystalline Al_(2)O_(3) to 12 GPa at room temperature were conducted and the ultrasonic result is in good agreement with previous reports.It demonstrates the feasibility of performing sound velocity measurements close to the mantle transition zone pressure condition in our laboratory.展开更多
A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heate...A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heaters connected in parallel. The temperature of the cell was able to reach 2500 ℃ by using 0.025 mm rhenium foils, and the temperature limit was increased by 25% compared with that of the traditional single-layer assembly. The power-temperature relationships for these two assemblies with different sizes were calibrated by using W/Re thermocouple at 20 GPa. When the volume of samples was the same, the DHA not only attained higher temperature, but also kept the holding time longer, compared to the traditional assembly. The results of more than ten experiments showed that the new 10/4 DHA with a relatively large sample size (2 mm in diameter and 4 mm in height) can work stably with the center temperature of the sample cavity exceeding 2300 ℃ under the pressure of 20 GPa.展开更多
Expansion of the pressure range of Kawai-type multi-anvil presses (KMAPs) with tungsten carbide (WC) anvils is called for, especially in the field of Earth science. However, no significant progress in pressure generat...Expansion of the pressure range of Kawai-type multi-anvil presses (KMAPs) with tungsten carbide (WC) anvils is called for, especially in the field of Earth science. However, no significant progress in pressure generation has been made for 40 years. Our recent studies have expanded the pressure generation of a KMAP with WC anvils to 65 GPa, which is the world record for high-pressure generation in this device and is more than 2.5 times higher than conventional pressure generation. We have also successfully generated pressures of about 50 GPa at high temperatures. This work reviews our recently developed technology for high-pressure generation. High-pressure generation at room temperature and at high temperature was attained by integration of the following techniques:① a precisely aligned guideblock system,② a high degree of hardness of the second-stage anvils,③ tapering of the second-stage anvil faces,④ a high-pressure cell consisting of materials with a high bulk modulus, and ⑤ high thermal insulation of the furnace. Our high-pressure technology will facilitate investigation of the phase stability and physical properties of materials under the conditions of the upper part of the lower mantle, and will permit the synthesis and characterization of novel materials.展开更多
The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios re...The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios require a more specialized approach,and some groups of patients may benefit from customized Ilizarov constructs.Engineering science has designed various external fixators for orthopedic purposes,and some of those have become the gold standard for specific clinical tasks.We aimed to determine the current state and novel modifications of specialized external fixators for specific clinical situations which are based on the principles of the Ilizarov method.They are half-pin-based fixators for temporal fracture fixation,ring or hybrid devices for gradual deformity correction,and compression-distraction devices tailored for definite limb segments.Gradual correction of deformities can be achieved with external hexapods incorporating universal reduction units.Alternatively,external fixators with special connection mechanisms are able to provide independent movement of the rings in six degrees of freedom.Deformity correction can be performed with combined or sequential use of external and internal fixators.Special devices were developed for moving the split fragment for revascularization of the tibia.The units of external frames on the foot were modified to consider its complex anatomy and the clinical needs ranging from correction of multi-plane deformities,joint arthrodesis to distraction arthroplasty.Mini-fixators are compact external fixators for small bones of the hand and foot.The varieties of external fixators based on the Ilizarov principles have been designed to fulfill an ultimate goal of improving treatment outcomes.展开更多
The uniaxial compressive strength(UCS)of rocks is a vital geomechanical parameter widely used for rock mass classification,stability analysis,and engineering design in rock engineering.Various UCS testing methods and ...The uniaxial compressive strength(UCS)of rocks is a vital geomechanical parameter widely used for rock mass classification,stability analysis,and engineering design in rock engineering.Various UCS testing methods and apparatuses have been proposed over the past few decades.The objective of the present study is to summarize the status and development in theories,test apparatuses,data processing of the existing testing methods for UCS measurement.It starts with elaborating the theories of these test methods.Then the test apparatus and development trends for UCS measurement are summarized,followed by a discussion on rock specimens for test apparatus,and data processing methods.Next,the method selection for UCS measurement is recommended.It reveals that the rock failure mechanism in the UCS testing methods can be divided into compression-shear,compression-tension,composite failure mode,and no obvious failure mode.The trends of these apparatuses are towards automation,digitization,precision,and multi-modal test.Two size correction methods are commonly used.One is to develop empirical correlation between the measured indices and the specimen size.The other is to use a standard specimen to calculate the size correction factor.Three to five input parameters are commonly utilized in soft computation models to predict the UCS of rocks.The selection of the test methods for the UCS measurement can be carried out according to the testing scenario and the specimen size.The engineers can gain a comprehensive understanding of the UCS testing methods and its potential developments in various rock engineering endeavors.展开更多
Objectives:Triple-negative breast cancer(TNBC)presents a major treatment challenge due to its aggressive behavior.The dysfunction of the Golgi apparatus(GA)contributes to the development of various cancers.This study ...Objectives:Triple-negative breast cancer(TNBC)presents a major treatment challenge due to its aggressive behavior.The dysfunction of the Golgi apparatus(GA)contributes to the development of various cancers.This study aimed to utilize GA-related genes(GARGs)to forecast the prognosis and immune profile of TNBC.Methods:The data were downloaded from The Cancer Genome Atlas(TCGA)database,including 175 TNBC and 99 healthy samples.The differentially expressed GARGs(DEGARGs)were analyzed using the TCGA biolinks package.The patients with TNBC were classified into two clusters utilizing the ConsensusClusterPlus package according to prognosis-related DEGARGs,followed by comparing the differences in prognosis and immune infiltration between the two clusters.Next,LASSO and stepwise Cox regression were applied to establish a GARGs signature to forecast the TNBC prognosis.The association of the GARGs signature with immune infiltrates and drug sensitivity was further explored.Results:In total,430 DEGARGs were identified between TNBC and healthy samples,among which 20 were related to TNBC prognosis.Two GARG-related molecular clusters associated with different survival times and immune heterogeneity were identified.A risk model for TNBC was established based on six GARGs,and the high-risk(HR)group exhibited a poor prognosis.The HR group demonstrated a distinctly high M2 macrophage infiltration and low M1 macrophage infiltration,which contributed to an immunosuppressive tumor microenvironment and thus led to poor prognosis of the HR group.Immune dysfunction scores and programmed cell death ligand 1(PD-L1)expression were substantially elevated in the HR group.The HR group showed increased sensitivity to anticancer drugs,such as cisplatin.Conclusion:Our findings suggest that GARGs are involved in the pathogenesis of TNBC and provide new insights into prognostic prediction.The identified clusters and GARGs signatures have the potential to guide individualized therapy.展开更多
Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this devic...Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this device,the complete shearedeformation process and long-term shear creep tests could be performed on rocks under constant normal stiffness(CNS)or constant normal loading(CNL)conditions in real-time at high temperature and true-triaxial stress.During the research and development process,five key technologies were successfully broken through:(1)the ability to perform true-triaxial compressioneshear loading tests on rock samples with high stiffness;(2)a shear box with ultra-low friction throughout the entire stress space of the rock sample during loading;(3)a control system capable of maintaining high stress for a long time and responding rapidly to the brittle fracture of a rock sample as well;(4)a refined ability to measure the volumetric deformation of rock samples subjected to true triaxial shearing;and(5)a heating system capable of maintaining uniform heating of the rock sample over a long time.By developing these technologies,loading under high true triaxial stress conditions was realized.The apparatus has a maximum normal stiffness of 1000 GPa/m and a maximum operating temperature of 300C.The differences in the surface temperature of the sample are constant to within5C.Five types of true triaxial shear tests were conducted on homogeneous sandstone to verify that the apparatus has good performance and reliability.The results show that temperature,lateral stress,normal stress and time influence the shear deformation,failure mode and strength of the sandstone.The novel apparatus can be reliably used to conduct true-triaxial shear tests on rocks subjected to high temperatures and stress.展开更多
In traditional high-pressure–temperature assembly design, priority has been given to temperature insulation and retention at high pressures.This limits the efficiency of cooling of samples at the end of experiments, ...In traditional high-pressure–temperature assembly design, priority has been given to temperature insulation and retention at high pressures.This limits the efficiency of cooling of samples at the end of experiments, with a negative impact on many studies in high-pressure Earth andplanetary science. Inefficient cooling of experiments containing molten phases at high temperature leads to the formation of quench textures,which makes it impossible to quantify key compositional parameters of the original molten phase, such as their volatile contents. Here,we present a new low-cost experimental assembly for rapid cooling in a six-anvil cubic press. This assembly not only retains high heatingefficiency and thermal insulation, but also enables a very high cooling rate (∼600 ℃/s from 1900 ℃ to the glass transition temperature).Without using expensive materials or external modification of the press, the cooling rate in an assembly (∼600 ℃/s) with cube lengths of38.5 mm is about ten times faster than that in the traditional assembly (∼60 ℃/s). Experiments yielding inhomogeneous quenched melttextures when the traditional assembly is used are shown to yield homogeneous silicate glass without quench textures when the rapid coolingassembly is used.展开更多
An improved X-ray apparatus that combines tensile testing and X-ray diffraction has been designed and constructed to conduct timeresolved experiments during uniaxial stretching.By utilizing mortise-like clamping jaws ...An improved X-ray apparatus that combines tensile testing and X-ray diffraction has been designed and constructed to conduct timeresolved experiments during uniaxial stretching.By utilizing mortise-like clamping jaws and dogbone-shaped specimens,this setup allows for the simultaneous recording of high-quality mechanical responses and 2D diffraction patterns due to the minimization of experimental errors from sample slippage or premature fracture.Furthermore,the local extension ratio can be accurately determined based on thickness variation,and the Hermans'orientation function was demonstrated to be a reliable method with high accuracy to calculate the segmental orientation parameter〈P_(2)〉in elastomeric samples under high degree of stretching.In summary,this innovative tensile-WAXD instrument has proven to be a promising and powerful technique for investigating the“stress-deformation-segmental orientation”relationship in elastomers with high extensibilities.展开更多
This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction betwee...This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.展开更多
This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional sh...This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional shear apparatus was utilized to conduct tests on remolded samples under both normal and frozen conditions to investigate the mechanical properties and deformation behavior of loess under complex stress conditions. The results indicate significant differences in the internal changes of soil particles, unfrozen water, and relative positions in soil samples under normal and frozen conditions, leading to noticeable variations in strength and strain development.In frozen state, loess experiences primarily compressive failure with a slow growth of cracks, while at normal temperature, it predominantly exhibits shear failure. With the increase in the principal stress angle, the deformation patterns of the soil samples under different conditions become essentially consistent, gradually transitioning from compression to extension, accompanied by a reduction in axial strength. The gradual increase in the principal stress axis angle(α) reduces the strength of the generalized shear stress and shear strain curves.Under an increasing α, frozen soil exhibits strain-hardening characteristics, with the maximum shear strength occurring at α = 45°. The intermediate principal stress coefficient(b) also significantly impacts the strength of frozen soil, with an increasing b resulting in a gradual decrease in generalized shear stress strength. This study provides a reference for comprehensively exploring the mechanical properties of soil under traffic load and a reliable theoretical basis for the design and maintenance of roadbeds.展开更多
The structural and histochemical changes of the egg apparatus in the polyembryonic rice ( Oryza sativa L.), ApⅢ with the highest frequence of additional embryos among the polyembryonic rice investigated, before an...The structural and histochemical changes of the egg apparatus in the polyembryonic rice ( Oryza sativa L.), ApⅢ with the highest frequence of additional embryos among the polyembryonic rice investigated, before and after fertilization were studied and compared with those of normal and other polyembryonic rices in a similar developmental period. A total of 2 932 ovules were observed and each of them contained only a single embryo sac with a set of egg apparatus. Among 1 655 embryo sacs, there were 1 643 embryo sacs (99.27%) with one normal egg apparatus in each embryo sac, and only 12 embryo sacs (0.73%) from the remainder with 4_celled egg apparatus, i.e. two eggs and two synergids. Neither the numerous poly_egg apparatus and egg_like cells, nor the double set of embryo sacs each containing one egg apparatus and other abnormal egg apparatus in single ovary, which were reported by earlier investigators to have high frequency of embryo production in SB_1 and ApⅣ, were observed. The egg cell was located at the subterminal site of the micropylar end of embryo sac. The cytoplasm of egg cell was rich in protein materials and polysaccharide grains, which did not disappear until the division of zygote. The prominent nucleus was closely surrounded by protein and polysaccharide grains, which did not disappear until the division of zygote. No cytological difference was found between egg cells from the normal and abnormal egg apparatus. The two synergids were fully developed and situated at the upper most part of the micropylar end of the mature embryo sac. In most embryo sacs, the synergids were flask_shaped with longer necks, and a widened cap_shaped top, in close contact with the micropyle. The synergids had a well developed filiform apparatus. The characteristic appearance of the filiform apparatus as well as the cap_neck region of synergids before and after pollen tube penetration were easily distinguishable from the egg cell. The structure, the stainability with Coomassie Brilliant Blue and PAS reaction, the process of accumulation, distribution and disapperance of the cytoplasmic protein materials and polysaccharide grains of the two synergids, the persistent and rarely the receptive synergids before and after pollen tube penetration, were closely similar to those of egg cell of the same developmental stage. In comparison with normal and other polyembryonic rice reported, the size of nucleus and nucleolus and their stainability also strongly resembled those of egg cell. Based on the results observed, the main conclusions are summarized as follows: (1) the additional embryos very frequently developed in the young and mature seed of polyembryonic rice ApⅢ were produced by one or two synergids of normal egg apparatus, rarely by 4_celled egg apparatus; (2) during fertilization, the synergids, in addition to the natural specific function of introducing pollen tube and transferring sperms to egg cell and central cell, could be closely associated with the potentiality to breed one or two additional embryos; and (3) as compared with that of normal or other polyembryonic rice it is firstly disclosed that in a few embryo sacs of ApⅢ, the cytoplasmic and nuclear structure, the active anabolism and catabolism of protein and polysaccharide materials and the delayed disorganization at the mid_basal region of the receptive and persistent synergid still remained unchanged before the division of zygote. Such salient features could be the predisposition for the origin of additional embryos in ApⅢ.展开更多
Pressure allows the precise tuning of a fundamental parameter, the interatomic distance, which controls the electronic structure and virtually all interatomic interactions that determine material properties. Hence, pr...Pressure allows the precise tuning of a fundamental parameter, the interatomic distance, which controls the electronic structure and virtually all interatomic interactions that determine material properties. Hence, pressure tuning is an effective tool in the search for new materials with enhanced properties. To realize pressure tuning on matter, large-volume press （LVP） apparatuses have been widely used not only to synthesize novel materials but also to implement the in situ measurement of physical properties. Herein, we introduce the LVP apparatuses, including belt-type, cubic anvil, and 6-8 type multi-anvil, that will be constructed at the Synergetic Extreme Condition User Facility （SECUF） at Jilin University. Typically, cell volumes of 1000 mm3 can be obtained at 20 GPa in a belt-type apparatus that is significantly larger than that obtained in a 6-8 type multi-anvil apparatus at the same pressure. Furthermore, the in situ measurement of physical prop- erties, including thermological, electrical, and mechanical behaviors, is coupled to these LVP apparatuses. Some typical results of both synthetic experiments and in situ measurements obtained from the LVP apparatuses are also reviewed.展开更多
The present paper deals with stridulation apparatuses,observed by SEM,of 6 species of the genus Agromyza from China (2 species among them are newly recorded to China).Some morphological terms are proposed for the ...The present paper deals with stridulation apparatuses,observed by SEM,of 6 species of the genus Agromyza from China (2 species among them are newly recorded to China).Some morphological terms are proposed for the first time,and a key to 6 species of Agromyza applied by the characteristics of stridulatory file is given.We also scheme out a diagram showing relationship between two stridulatory file types.展开更多
Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella(MMAF).Distinct projections encircling the central microtubules of the spermatozoal axoneme play p...Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella(MMAF).Distinct projections encircling the central microtubules of the spermatozoal axoneme play pivotal roles in flagellar bending and spermatozoal movement.Mammalian sperm-associated antigen 17(SPAG17)encodes a conserved axonemal protein of cilia and flagella,forming part of the C1a projection of the central apparatus,with functions related to ciliary/flagellar motility,skeletal growth,and male fertility.This study investigated two novel homozygous SPAG17 mutations(M1:NM_206996.2,c.829+1G>T,p.Asp212_Glu276del;and M2:c.2120del,p.Leu707*)identified in four infertile patients from two consanguineous Pakistani families.These patients displayed the MMAF phenotype confirmed by Papanicolaou staining and scanning electron microscopy assays of spermatozoa.Quantitative real-time polymerase chain reaction(PCR)of patients’spermatozoa also revealed a significant decrease in SPAG17 mRNA expression,and immunofluorescence staining showed the absence of SPAG17 protein signals along the flagella.However,no apparent ciliary-related symptoms or skeletal malformations were observed in the chest X-rays of any of the patients.Transmission electron microscopy of axoneme cross-sections from the patients showed incomplete C1a projection and a higher frequency of missing microtubule doublets 1 and 9 compared with those from fertile controls.Immunofluorescence staining and Western blot analyses of spermatogenesis-associated protein 17(SPATA17),a component of the C1a projection,and sperm-associated antigen 6(SPAG6),a marker of the spring layer,revealed disrupted expression of both proteins in the patients’spermatozoa.Altogether,these findings demonstrated that SPAG17 maintains the integrity of spermatozoal flagellar axoneme,expanding the phenotypic spectrum of SPAG17 mutations in humans.展开更多
Strategies for increasing rice yield are needed to keep pace with the expected global population growth and sustainably address the challenges posed by climate change.In Southeast Asian countries,rice farming benefits...Strategies for increasing rice yield are needed to keep pace with the expected global population growth and sustainably address the challenges posed by climate change.In Southeast Asian countries,rice farming benefits from the use of Azolla spp.for nitrogen supply.By virtue of their symbiosis with the nitrogen-fixing cyanobacterium Trichormus azollae,Azolla spp.are ferns that release nitrogen into the environment upon biomass decomposition.However,whether and to what extent actively growing Azolla plants influence the development of co-cultivated rice seedlings remains unclear.To address this,rice(Oryza sativa L.var.Kitaake)seedlings were co-cultivated hydroponically with Azolla filiculoides for up to two months.Morphological changes in rice roots and aerial organs were assessed alongside nitric oxide assays in rice roots,root transcriptomics,and targeted hormonomics of rice roots,leaves,and growth media.Here,we showed that co-cultivation with actively growing A.filiculoides alters rice root architecture by inducing a nitric oxide boost and accelerates leaf and tiller differentiation and proliferation.Overall,this study provides an in-depth analysis of the morphogenetic effects of co-cultivated A.filiculoides on rice during early vegetative growth.It also paves the way for studies assessing whether A.filiculoides co-cultivation primes rice plants to better withstand abiotic and biotic stresses.展开更多
Healthy aging is a common goal for humanity and society,and one key to achieving it is the rejuvenation of senescent resident stem cells and empowerment of aging organ regeneration.However,the mechanistic understandin...Healthy aging is a common goal for humanity and society,and one key to achieving it is the rejuvenation of senescent resident stem cells and empowerment of aging organ regeneration.However,the mechanistic understandings of stem cell senescence and the potential strategies to counteract it remain elusive.Here,we reveal that the aging bone microenvironment impairs the Golgi apparatus thus diminishing mesenchymal stem cell(MSC)function and regeneration.Interestingly,replenishment of cell aggregates-derived extracellular vesicles(CA-EVs)rescues Golgi dysfunction and empowers senescent MSCs through the Golgi regulatory protein Syntaxin 5.Importantly,in vivo administration of CA-EVs significantly enhanced the bone defect repair rate and improved bone mass in aging mice,suggesting their therapeutic value for treating age-related osteoporosis and promoting bone regeneration.Collectively,our findings provide insights into Golgi regulation in stem cell senescence and bone aging,which further highlight CA-EVs as a potential rejuvenative approach for aging bone regeneration.展开更多
An approach for studying the adsorption and desorption behaviors of single-stranded DNA（ ssDNA） molecules on the mica surface by the surface forces apparatus（ SFA） is reported,which can be used to characterize the...An approach for studying the adsorption and desorption behaviors of single-stranded DNA（ ssDNA） molecules on the mica surface by the surface forces apparatus（ SFA） is reported,which can be used to characterize the precise thickness,configuration and mechanical properties of ssDNA layers on the mica surface at a certain buffer solution. The formation of ss DNA layers is first studied by tuning the ssDNA concentrations, and the experimental results indicate that the ss DNA concentration of 100 ng / μL is ideal for forming a ssDNA monolayer structure on the mica surface, and the hardwall value measured to be 1.04 nm under this circumstance is regarded as the thickness of the ssDNA monolayer confined on mica. The desorption behavior of ssDNA molecules from the mica surface is further studied by observing and comparing different shapes of the force-distance curves under certain conditions. It is found that the desorption of ss DNA molecules from the mica surface occurs as the monovalent salts are added into the gap buffer. It is inferred that the competition effect between monovalent and divalent salts can induce the release of ssDNA from substrate.The results also reveal that 10 mmol / L monovalent salts（ Na~＋）is sufficient for the desorption of ssDNA from mica. This work provides an applicable method to study the binding mechanism of ss DNA molecules on inorganic substrates.展开更多
Almost all aspects of conodont research rely on a sound taxonomy based on comparative analysis.This is founded on hypotheses of homology which ultimately rest on knowledge of the location of elements in the apparatus....Almost all aspects of conodont research rely on a sound taxonomy based on comparative analysis.This is founded on hypotheses of homology which ultimately rest on knowledge of the location of elements in the apparatus.Natural assemblages—fossils that preserve the articulated remains of the conodont skeletal apparatus—provide our only direct evidence for element location,but very few are known from the Late Triassic.Here we describe fused clusters(natural assemblages)from the late Norian limestone beds of the Nanshuba Formation in Baoshan,Yunnan Province,southwestern China.Recurrent arrangements and juxtaposition of S and M elements in multiple clusters reveal the composition of the apparatus of Mockina and,probably,Parvigondolella.They indicate that these taxa had a standard 15 elements ozarkodinid apparatus,and provide new insights into the morphology of the elements occupying the P2,M and S locations of the apparatus.The apparatus comprised a single alate(hibbardelliform)S0 element,paired breviform digyrate(grodelliform)S1 and(enantiognathiform)S2 elements,paired bipennate(hindeodelliform)S3 and S4 elements,paired breviform digyrate(cypridodellifrom)M elements,paired,modified-angulate P2 elements(with reduced or lacking‘posterior’process)and segminiplanate(mockiniform and parvigondolelliform)P1 elements.Our results will allow testing of the hypothesis that Mockina,Parvigondolella and Misikella—critical taxa in Late Triassic biostratigraphy—are closely related and possessed morphologically similar elements in homologous locations.展开更多
The tried and tested multianvil apparatus has been widely used for high-pressure and hightemperature experimental studies in Earth science. As a result, many important results have been obtained for a better understan...The tried and tested multianvil apparatus has been widely used for high-pressure and hightemperature experimental studies in Earth science. As a result, many important results have been obtained for a better understanding of the components, structure and evolution of the Earth. Due to the strength limi- tation of materials, the attainable multianvil pressure is generally limited to about 30 GPa （corresponding to about 900 km of the depth in the Earth） when tungsten carbide cubes are adopted as second-stage anvils. Compared with tungsten carbide, the sintered diamond is a much harder material. The sintered diamond cubes were introduced as second-stage anvils in a 6--8 type multianvil apparatus in the 1980s, which largely enhanced the capacity of pressure generation in a large volume press. With the development of material synthesis and processing techniques, a large sintered diamond cube （14 ram） is now available. Recently, maximum attainable pressures reaching higher than 90 GPa （corresponding to about 2700 km of the depth in the Earth） have been generated at room temperature by adopting 14-mm sintered diamond anvils. Using this technique, a few researches have been carried out by the quenched method or combined with synchrotron radiation in situ observation. In this paper we review the properties of sintered diamond and the evolu- tion of pressure generation using sintered diamond anvils. As-yet unsolved problems and perspectives for uses in Earth Science are also discussed.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.41873075the West Light Foundation of The Chinese Academy of Sciences。
文摘We performed the pressure calibration to 12 GPa for 14/6 type(octahedron edge length/WC truncated edge length,in mm) cell assembly in DS 6 × 1400 multi-anvil apparatus by using the phase transitions in Bi(Ⅰ-Ⅱ2.55 GPa,Ⅲ-Ⅴ 7.67 GPa) and ZnTe(LPP-HPP Ⅰ 9.6 GPa,HPP Ⅰ-Ⅱ 12.0 GPa).As verification and application,sound velocity measurements on poly crystalline Al_(2)O_(3) to 12 GPa at room temperature were conducted and the ultrasonic result is in good agreement with previous reports.It demonstrates the feasibility of performing sound velocity measurements close to the mantle transition zone pressure condition in our laboratory.
基金Project supported by the National Natural Science Foundation of China (Grant No. 51872189)the Fundamental Research Funds for the Central Universities, China (Grant No. 2018SCUH0022).
文摘A new heating method is proposed to increase the cell temperature of the 6-8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heaters connected in parallel. The temperature of the cell was able to reach 2500 ℃ by using 0.025 mm rhenium foils, and the temperature limit was increased by 25% compared with that of the traditional single-layer assembly. The power-temperature relationships for these two assemblies with different sizes were calibrated by using W/Re thermocouple at 20 GPa. When the volume of samples was the same, the DHA not only attained higher temperature, but also kept the holding time longer, compared to the traditional assembly. The results of more than ten experiments showed that the new 10/4 DHA with a relatively large sample size (2 mm in diameter and 4 mm in height) can work stably with the center temperature of the sample cavity exceeding 2300 ℃ under the pressure of 20 GPa.
基金supported by an Alexander von Humboldt Postdoctoral Fellowship to T.Ishiifunding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (787527)
文摘Expansion of the pressure range of Kawai-type multi-anvil presses (KMAPs) with tungsten carbide (WC) anvils is called for, especially in the field of Earth science. However, no significant progress in pressure generation has been made for 40 years. Our recent studies have expanded the pressure generation of a KMAP with WC anvils to 65 GPa, which is the world record for high-pressure generation in this device and is more than 2.5 times higher than conventional pressure generation. We have also successfully generated pressures of about 50 GPa at high temperatures. This work reviews our recently developed technology for high-pressure generation. High-pressure generation at room temperature and at high temperature was attained by integration of the following techniques:① a precisely aligned guideblock system,② a high degree of hardness of the second-stage anvils,③ tapering of the second-stage anvil faces,④ a high-pressure cell consisting of materials with a high bulk modulus, and ⑤ high thermal insulation of the furnace. Our high-pressure technology will facilitate investigation of the phase stability and physical properties of materials under the conditions of the upper part of the lower mantle, and will permit the synthesis and characterization of novel materials.
文摘The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios require a more specialized approach,and some groups of patients may benefit from customized Ilizarov constructs.Engineering science has designed various external fixators for orthopedic purposes,and some of those have become the gold standard for specific clinical tasks.We aimed to determine the current state and novel modifications of specialized external fixators for specific clinical situations which are based on the principles of the Ilizarov method.They are half-pin-based fixators for temporal fracture fixation,ring or hybrid devices for gradual deformity correction,and compression-distraction devices tailored for definite limb segments.Gradual correction of deformities can be achieved with external hexapods incorporating universal reduction units.Alternatively,external fixators with special connection mechanisms are able to provide independent movement of the rings in six degrees of freedom.Deformity correction can be performed with combined or sequential use of external and internal fixators.Special devices were developed for moving the split fragment for revascularization of the tibia.The units of external frames on the foot were modified to consider its complex anatomy and the clinical needs ranging from correction of multi-plane deformities,joint arthrodesis to distraction arthroplasty.Mini-fixators are compact external fixators for small bones of the hand and foot.The varieties of external fixators based on the Ilizarov principles have been designed to fulfill an ultimate goal of improving treatment outcomes.
基金the National Natural Science Foundation of China(Grant Nos.52308403 and 52079068)the Yunlong Lake Laboratory of Deep Underground Science and Engineering(No.104023005)the China Postdoctoral Science Foundation(Grant No.2023M731998)for funding provided to this work.
文摘The uniaxial compressive strength(UCS)of rocks is a vital geomechanical parameter widely used for rock mass classification,stability analysis,and engineering design in rock engineering.Various UCS testing methods and apparatuses have been proposed over the past few decades.The objective of the present study is to summarize the status and development in theories,test apparatuses,data processing of the existing testing methods for UCS measurement.It starts with elaborating the theories of these test methods.Then the test apparatus and development trends for UCS measurement are summarized,followed by a discussion on rock specimens for test apparatus,and data processing methods.Next,the method selection for UCS measurement is recommended.It reveals that the rock failure mechanism in the UCS testing methods can be divided into compression-shear,compression-tension,composite failure mode,and no obvious failure mode.The trends of these apparatuses are towards automation,digitization,precision,and multi-modal test.Two size correction methods are commonly used.One is to develop empirical correlation between the measured indices and the specimen size.The other is to use a standard specimen to calculate the size correction factor.Three to five input parameters are commonly utilized in soft computation models to predict the UCS of rocks.The selection of the test methods for the UCS measurement can be carried out according to the testing scenario and the specimen size.The engineers can gain a comprehensive understanding of the UCS testing methods and its potential developments in various rock engineering endeavors.
文摘Objectives:Triple-negative breast cancer(TNBC)presents a major treatment challenge due to its aggressive behavior.The dysfunction of the Golgi apparatus(GA)contributes to the development of various cancers.This study aimed to utilize GA-related genes(GARGs)to forecast the prognosis and immune profile of TNBC.Methods:The data were downloaded from The Cancer Genome Atlas(TCGA)database,including 175 TNBC and 99 healthy samples.The differentially expressed GARGs(DEGARGs)were analyzed using the TCGA biolinks package.The patients with TNBC were classified into two clusters utilizing the ConsensusClusterPlus package according to prognosis-related DEGARGs,followed by comparing the differences in prognosis and immune infiltration between the two clusters.Next,LASSO and stepwise Cox regression were applied to establish a GARGs signature to forecast the TNBC prognosis.The association of the GARGs signature with immune infiltrates and drug sensitivity was further explored.Results:In total,430 DEGARGs were identified between TNBC and healthy samples,among which 20 were related to TNBC prognosis.Two GARG-related molecular clusters associated with different survival times and immune heterogeneity were identified.A risk model for TNBC was established based on six GARGs,and the high-risk(HR)group exhibited a poor prognosis.The HR group demonstrated a distinctly high M2 macrophage infiltration and low M1 macrophage infiltration,which contributed to an immunosuppressive tumor microenvironment and thus led to poor prognosis of the HR group.Immune dysfunction scores and programmed cell death ligand 1(PD-L1)expression were substantially elevated in the HR group.The HR group showed increased sensitivity to anticancer drugs,such as cisplatin.Conclusion:Our findings suggest that GARGs are involved in the pathogenesis of TNBC and provide new insights into prognostic prediction.The identified clusters and GARGs signatures have the potential to guide individualized therapy.
基金financial support from the National Natural Science Foundation of China(Grant Nos.52209125 and 51839003).
文摘Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this device,the complete shearedeformation process and long-term shear creep tests could be performed on rocks under constant normal stiffness(CNS)or constant normal loading(CNL)conditions in real-time at high temperature and true-triaxial stress.During the research and development process,five key technologies were successfully broken through:(1)the ability to perform true-triaxial compressioneshear loading tests on rock samples with high stiffness;(2)a shear box with ultra-low friction throughout the entire stress space of the rock sample during loading;(3)a control system capable of maintaining high stress for a long time and responding rapidly to the brittle fracture of a rock sample as well;(4)a refined ability to measure the volumetric deformation of rock samples subjected to true triaxial shearing;and(5)a heating system capable of maintaining uniform heating of the rock sample over a long time.By developing these technologies,loading under high true triaxial stress conditions was realized.The apparatus has a maximum normal stiffness of 1000 GPa/m and a maximum operating temperature of 300C.The differences in the surface temperature of the sample are constant to within5C.Five types of true triaxial shear tests were conducted on homogeneous sandstone to verify that the apparatus has good performance and reliability.The results show that temperature,lateral stress,normal stress and time influence the shear deformation,failure mode and strength of the sandstone.The novel apparatus can be reliably used to conduct true-triaxial shear tests on rocks subjected to high temperatures and stress.
基金supported by National Natural Science Foundation of China Grant No.42250105 to Y.L.The Center for High Pressure Science and Technology Advanced Research is supported by the National Science Foundation of China(Grant Nos.U1530402 and U1930401).
文摘In traditional high-pressure–temperature assembly design, priority has been given to temperature insulation and retention at high pressures.This limits the efficiency of cooling of samples at the end of experiments, with a negative impact on many studies in high-pressure Earth andplanetary science. Inefficient cooling of experiments containing molten phases at high temperature leads to the formation of quench textures,which makes it impossible to quantify key compositional parameters of the original molten phase, such as their volatile contents. Here,we present a new low-cost experimental assembly for rapid cooling in a six-anvil cubic press. This assembly not only retains high heatingefficiency and thermal insulation, but also enables a very high cooling rate (∼600 ℃/s from 1900 ℃ to the glass transition temperature).Without using expensive materials or external modification of the press, the cooling rate in an assembly (∼600 ℃/s) with cube lengths of38.5 mm is about ten times faster than that in the traditional assembly (∼60 ℃/s). Experiments yielding inhomogeneous quenched melttextures when the traditional assembly is used are shown to yield homogeneous silicate glass without quench textures when the rapid coolingassembly is used.
基金financial support of China CSC Scholarship(No.201604910522).
文摘An improved X-ray apparatus that combines tensile testing and X-ray diffraction has been designed and constructed to conduct timeresolved experiments during uniaxial stretching.By utilizing mortise-like clamping jaws and dogbone-shaped specimens,this setup allows for the simultaneous recording of high-quality mechanical responses and 2D diffraction patterns due to the minimization of experimental errors from sample slippage or premature fracture.Furthermore,the local extension ratio can be accurately determined based on thickness variation,and the Hermans'orientation function was demonstrated to be a reliable method with high accuracy to calculate the segmental orientation parameter〈P_(2)〉in elastomeric samples under high degree of stretching.In summary,this innovative tensile-WAXD instrument has proven to be a promising and powerful technique for investigating the“stress-deformation-segmental orientation”relationship in elastomers with high extensibilities.
基金CAS Photon Science Research Center for Carbon DioxideCAS President’s International Fellowship Initiative(2024PVA0097)+1 种基金National Key Research and Development Program of China(2017YFA0403000,2017YFA0402800)National Natural Science Foundation of China(U1932201,U1732121)。
文摘This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.
基金This work was supported by the National Natural Science Foundation of China(Nos.42161026&41801046)the Natural Science Foundation of Qinghai Province(No.2023-ZJ-934M)the Youth Research Foundation of Qinghai University(No.2022-QGY-5).
文摘This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional shear apparatus was utilized to conduct tests on remolded samples under both normal and frozen conditions to investigate the mechanical properties and deformation behavior of loess under complex stress conditions. The results indicate significant differences in the internal changes of soil particles, unfrozen water, and relative positions in soil samples under normal and frozen conditions, leading to noticeable variations in strength and strain development.In frozen state, loess experiences primarily compressive failure with a slow growth of cracks, while at normal temperature, it predominantly exhibits shear failure. With the increase in the principal stress angle, the deformation patterns of the soil samples under different conditions become essentially consistent, gradually transitioning from compression to extension, accompanied by a reduction in axial strength. The gradual increase in the principal stress axis angle(α) reduces the strength of the generalized shear stress and shear strain curves.Under an increasing α, frozen soil exhibits strain-hardening characteristics, with the maximum shear strength occurring at α = 45°. The intermediate principal stress coefficient(b) also significantly impacts the strength of frozen soil, with an increasing b resulting in a gradual decrease in generalized shear stress strength. This study provides a reference for comprehensively exploring the mechanical properties of soil under traffic load and a reliable theoretical basis for the design and maintenance of roadbeds.
文摘The structural and histochemical changes of the egg apparatus in the polyembryonic rice ( Oryza sativa L.), ApⅢ with the highest frequence of additional embryos among the polyembryonic rice investigated, before and after fertilization were studied and compared with those of normal and other polyembryonic rices in a similar developmental period. A total of 2 932 ovules were observed and each of them contained only a single embryo sac with a set of egg apparatus. Among 1 655 embryo sacs, there were 1 643 embryo sacs (99.27%) with one normal egg apparatus in each embryo sac, and only 12 embryo sacs (0.73%) from the remainder with 4_celled egg apparatus, i.e. two eggs and two synergids. Neither the numerous poly_egg apparatus and egg_like cells, nor the double set of embryo sacs each containing one egg apparatus and other abnormal egg apparatus in single ovary, which were reported by earlier investigators to have high frequency of embryo production in SB_1 and ApⅣ, were observed. The egg cell was located at the subterminal site of the micropylar end of embryo sac. The cytoplasm of egg cell was rich in protein materials and polysaccharide grains, which did not disappear until the division of zygote. The prominent nucleus was closely surrounded by protein and polysaccharide grains, which did not disappear until the division of zygote. No cytological difference was found between egg cells from the normal and abnormal egg apparatus. The two synergids were fully developed and situated at the upper most part of the micropylar end of the mature embryo sac. In most embryo sacs, the synergids were flask_shaped with longer necks, and a widened cap_shaped top, in close contact with the micropyle. The synergids had a well developed filiform apparatus. The characteristic appearance of the filiform apparatus as well as the cap_neck region of synergids before and after pollen tube penetration were easily distinguishable from the egg cell. The structure, the stainability with Coomassie Brilliant Blue and PAS reaction, the process of accumulation, distribution and disapperance of the cytoplasmic protein materials and polysaccharide grains of the two synergids, the persistent and rarely the receptive synergids before and after pollen tube penetration, were closely similar to those of egg cell of the same developmental stage. In comparison with normal and other polyembryonic rice reported, the size of nucleus and nucleolus and their stainability also strongly resembled those of egg cell. Based on the results observed, the main conclusions are summarized as follows: (1) the additional embryos very frequently developed in the young and mature seed of polyembryonic rice ApⅢ were produced by one or two synergids of normal egg apparatus, rarely by 4_celled egg apparatus; (2) during fertilization, the synergids, in addition to the natural specific function of introducing pollen tube and transferring sperms to egg cell and central cell, could be closely associated with the potentiality to breed one or two additional embryos; and (3) as compared with that of normal or other polyembryonic rice it is firstly disclosed that in a few embryo sacs of ApⅢ, the cytoplasmic and nuclear structure, the active anabolism and catabolism of protein and polysaccharide materials and the delayed disorganization at the mid_basal region of the receptive and persistent synergid still remained unchanged before the division of zygote. Such salient features could be the predisposition for the origin of additional embryos in ApⅢ.
文摘Pressure allows the precise tuning of a fundamental parameter, the interatomic distance, which controls the electronic structure and virtually all interatomic interactions that determine material properties. Hence, pressure tuning is an effective tool in the search for new materials with enhanced properties. To realize pressure tuning on matter, large-volume press （LVP） apparatuses have been widely used not only to synthesize novel materials but also to implement the in situ measurement of physical properties. Herein, we introduce the LVP apparatuses, including belt-type, cubic anvil, and 6-8 type multi-anvil, that will be constructed at the Synergetic Extreme Condition User Facility （SECUF） at Jilin University. Typically, cell volumes of 1000 mm3 can be obtained at 20 GPa in a belt-type apparatus that is significantly larger than that obtained in a 6-8 type multi-anvil apparatus at the same pressure. Furthermore, the in situ measurement of physical prop- erties, including thermological, electrical, and mechanical behaviors, is coupled to these LVP apparatuses. Some typical results of both synthetic experiments and in situ measurements obtained from the LVP apparatuses are also reviewed.
文摘The present paper deals with stridulation apparatuses,observed by SEM,of 6 species of the genus Agromyza from China (2 species among them are newly recorded to China).Some morphological terms are proposed for the first time,and a key to 6 species of Agromyza applied by the characteristics of stridulatory file is given.We also scheme out a diagram showing relationship between two stridulatory file types.
基金supported by the National Natural Science Foundation of China(No.82171599 and No.32270901)the National Key Research and Developmental Program of China(2022YFC2702601 and 2022YFA0806303)the Global Select Project(DJKLX-2022010)of the Institute of Health and Medicine,Hefei Comprehensive National Science Center.
文摘Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella(MMAF).Distinct projections encircling the central microtubules of the spermatozoal axoneme play pivotal roles in flagellar bending and spermatozoal movement.Mammalian sperm-associated antigen 17(SPAG17)encodes a conserved axonemal protein of cilia and flagella,forming part of the C1a projection of the central apparatus,with functions related to ciliary/flagellar motility,skeletal growth,and male fertility.This study investigated two novel homozygous SPAG17 mutations(M1:NM_206996.2,c.829+1G>T,p.Asp212_Glu276del;and M2:c.2120del,p.Leu707*)identified in four infertile patients from two consanguineous Pakistani families.These patients displayed the MMAF phenotype confirmed by Papanicolaou staining and scanning electron microscopy assays of spermatozoa.Quantitative real-time polymerase chain reaction(PCR)of patients’spermatozoa also revealed a significant decrease in SPAG17 mRNA expression,and immunofluorescence staining showed the absence of SPAG17 protein signals along the flagella.However,no apparent ciliary-related symptoms or skeletal malformations were observed in the chest X-rays of any of the patients.Transmission electron microscopy of axoneme cross-sections from the patients showed incomplete C1a projection and a higher frequency of missing microtubule doublets 1 and 9 compared with those from fertile controls.Immunofluorescence staining and Western blot analyses of spermatogenesis-associated protein 17(SPATA17),a component of the C1a projection,and sperm-associated antigen 6(SPAG6),a marker of the spring layer,revealed disrupted expression of both proteins in the patients’spermatozoa.Altogether,these findings demonstrated that SPAG17 maintains the integrity of spermatozoal flagellar axoneme,expanding the phenotypic spectrum of SPAG17 mutations in humans.
基金carried out within the PRIN project 2017 (Prot.2017N5LBZK): A multidisciplinary approach to gain sustainable improvement of rice productivity through the co-cultivation with the fern Azolla and its cyanobacterial symbiont financed by the Italian Ministry of Research (MUR), the Agritech National Research Center that received funding from the European Union Next-Generation EU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR) – MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4 – D.D. 1032 17/06/2022, CN00000022)within the Tow Ards Next GENeration Crops Project, reg. no. CZ.02.01.01/00/22_008/0004581 of the ERDF program Johannes Amos Comeniusfunded by ‘ON Foods’ - Research and innovation network on food and nutrition Sustainability, Safety and Security – Working ON Foods B83C22004790001 PE_00000003 project.
文摘Strategies for increasing rice yield are needed to keep pace with the expected global population growth and sustainably address the challenges posed by climate change.In Southeast Asian countries,rice farming benefits from the use of Azolla spp.for nitrogen supply.By virtue of their symbiosis with the nitrogen-fixing cyanobacterium Trichormus azollae,Azolla spp.are ferns that release nitrogen into the environment upon biomass decomposition.However,whether and to what extent actively growing Azolla plants influence the development of co-cultivated rice seedlings remains unclear.To address this,rice(Oryza sativa L.var.Kitaake)seedlings were co-cultivated hydroponically with Azolla filiculoides for up to two months.Morphological changes in rice roots and aerial organs were assessed alongside nitric oxide assays in rice roots,root transcriptomics,and targeted hormonomics of rice roots,leaves,and growth media.Here,we showed that co-cultivation with actively growing A.filiculoides alters rice root architecture by inducing a nitric oxide boost and accelerates leaf and tiller differentiation and proliferation.Overall,this study provides an in-depth analysis of the morphogenetic effects of co-cultivated A.filiculoides on rice during early vegetative growth.It also paves the way for studies assessing whether A.filiculoides co-cultivation primes rice plants to better withstand abiotic and biotic stresses.
基金supported by grants from the National Natural Science Foundation of China(81930025,82201013,82371020,82370949,82100992)the Young Science and Technology Rising Star Project of Shaanxi Province(2023KJXX-027)the China Postdoctoral Science Foundation(BX20230485).
文摘Healthy aging is a common goal for humanity and society,and one key to achieving it is the rejuvenation of senescent resident stem cells and empowerment of aging organ regeneration.However,the mechanistic understandings of stem cell senescence and the potential strategies to counteract it remain elusive.Here,we reveal that the aging bone microenvironment impairs the Golgi apparatus thus diminishing mesenchymal stem cell(MSC)function and regeneration.Interestingly,replenishment of cell aggregates-derived extracellular vesicles(CA-EVs)rescues Golgi dysfunction and empowers senescent MSCs through the Golgi regulatory protein Syntaxin 5.Importantly,in vivo administration of CA-EVs significantly enhanced the bone defect repair rate and improved bone mass in aging mice,suggesting their therapeutic value for treating age-related osteoporosis and promoting bone regeneration.Collectively,our findings provide insights into Golgi regulation in stem cell senescence and bone aging,which further highlight CA-EVs as a potential rejuvenative approach for aging bone regeneration.
基金The National Basic Research Program of China(973Program)(No.2011CB707605)the Fundamental Research Funds for the Central Universities(No.2242015K42085)+1 种基金the Scientific Innovation Research of College Graduates in Jiangsu Province(No.KYLX-0100)the Research Start-Up Fund of Southeast University
文摘An approach for studying the adsorption and desorption behaviors of single-stranded DNA（ ssDNA） molecules on the mica surface by the surface forces apparatus（ SFA） is reported,which can be used to characterize the precise thickness,configuration and mechanical properties of ssDNA layers on the mica surface at a certain buffer solution. The formation of ss DNA layers is first studied by tuning the ssDNA concentrations, and the experimental results indicate that the ss DNA concentration of 100 ng / μL is ideal for forming a ssDNA monolayer structure on the mica surface, and the hardwall value measured to be 1.04 nm under this circumstance is regarded as the thickness of the ssDNA monolayer confined on mica. The desorption behavior of ssDNA molecules from the mica surface is further studied by observing and comparing different shapes of the force-distance curves under certain conditions. It is found that the desorption of ss DNA molecules from the mica surface occurs as the monovalent salts are added into the gap buffer. It is inferred that the competition effect between monovalent and divalent salts can induce the release of ssDNA from substrate.The results also reveal that 10 mmol / L monovalent salts（ Na~＋）is sufficient for the desorption of ssDNA from mica. This work provides an applicable method to study the binding mechanism of ss DNA molecules on inorganic substrates.
基金supported by the National Natural Sciences Foundation of China(Nos.41830320,41972033,41572324)。
文摘Almost all aspects of conodont research rely on a sound taxonomy based on comparative analysis.This is founded on hypotheses of homology which ultimately rest on knowledge of the location of elements in the apparatus.Natural assemblages—fossils that preserve the articulated remains of the conodont skeletal apparatus—provide our only direct evidence for element location,but very few are known from the Late Triassic.Here we describe fused clusters(natural assemblages)from the late Norian limestone beds of the Nanshuba Formation in Baoshan,Yunnan Province,southwestern China.Recurrent arrangements and juxtaposition of S and M elements in multiple clusters reveal the composition of the apparatus of Mockina and,probably,Parvigondolella.They indicate that these taxa had a standard 15 elements ozarkodinid apparatus,and provide new insights into the morphology of the elements occupying the P2,M and S locations of the apparatus.The apparatus comprised a single alate(hibbardelliform)S0 element,paired breviform digyrate(grodelliform)S1 and(enantiognathiform)S2 elements,paired bipennate(hindeodelliform)S3 and S4 elements,paired breviform digyrate(cypridodellifrom)M elements,paired,modified-angulate P2 elements(with reduced or lacking‘posterior’process)and segminiplanate(mockiniform and parvigondolelliform)P1 elements.Our results will allow testing of the hypothesis that Mockina,Parvigondolella and Misikella—critical taxa in Late Triassic biostratigraphy—are closely related and possessed morphologically similar elements in homologous locations.
基金supported by National Natural Science Foundation of China(Grant Nos.40973045 and 41010104017)
文摘The tried and tested multianvil apparatus has been widely used for high-pressure and hightemperature experimental studies in Earth science. As a result, many important results have been obtained for a better understanding of the components, structure and evolution of the Earth. Due to the strength limi- tation of materials, the attainable multianvil pressure is generally limited to about 30 GPa （corresponding to about 900 km of the depth in the Earth） when tungsten carbide cubes are adopted as second-stage anvils. Compared with tungsten carbide, the sintered diamond is a much harder material. The sintered diamond cubes were introduced as second-stage anvils in a 6--8 type multianvil apparatus in the 1980s, which largely enhanced the capacity of pressure generation in a large volume press. With the development of material synthesis and processing techniques, a large sintered diamond cube （14 ram） is now available. Recently, maximum attainable pressures reaching higher than 90 GPa （corresponding to about 2700 km of the depth in the Earth） have been generated at room temperature by adopting 14-mm sintered diamond anvils. Using this technique, a few researches have been carried out by the quenched method or combined with synchrotron radiation in situ observation. In this paper we review the properties of sintered diamond and the evolu- tion of pressure generation using sintered diamond anvils. As-yet unsolved problems and perspectives for uses in Earth Science are also discussed.
