To investigate the mechanisms of apigenin(API)and proanthocyanidins(PC)in soothing sensitive skin(SS),a mast cell degranulation model was established by stimulating RBL-2H3 cells with the calcium ionophore A23187.Base...To investigate the mechanisms of apigenin(API)and proanthocyanidins(PC)in soothing sensitive skin(SS),a mast cell degranulation model was established by stimulating RBL-2H3 cells with the calcium ionophore A23187.Based on the combinatorial experiments,it was found that when API and PC were combined at the molar ratios of 4∶1 and 2∶1,they exhibited the antagonistic effects on histamine release(combination index CI>1);when they are combined at the molar ratios of 1∶1,1∶2 or 1∶4,they showed the synergistic effects on histamine release(CI<1).Among them,the combination of API and PC at a molar ratio of 1∶1 showed the better potent synergistic antihistamine release effect(CI=0.70).Histamine is a hallmark of the mast cell degranulation,consequently,the combination of API and PC at a molar ratio of 1∶1 yields the better efficiency in inhibiting the mast cell degranulation with the lowest IC_(50)value.Compared to the utilization of API or PC alone,the IC_(50)value was reduced by 11.150 and 6.503μmol/L,respectively.Compared to the positive control paeonol(PA),the treatment with the combination significantly reduced theβ-hex secretion,decreased the F-actin cytoskeleton rearrangement,and markedly suppressed the release of TNF-α,IL-4,and MCP-1.Further studies on the signaling pathways related to the mast cell degranulation indicated that the combination effectively inhibited the intracellular Ca^(2+)influx and significantly suppressed the phosphorylation of calmodulin-dependent protein kinase(CaMK)and phospholipase C/protein kinase C(PLC/PKC).In summary,the combination of API and PC at a molar ratio of 1∶1 exhibited the better synergistic antagonistic effect on the histamine release,inhibited the mast cell degranulation model activation by reducing Ca^(2+)influx and inhibiting the activation of Ca^(2+)/CaMK and PLC/PKC pathways,stabilized the cell membranes,regulated the inflammatory factor secretion,and exerted an effect in alleviating sensitive skin.展开更多
The influence of pre-stretching on quench sensitive effect of high strength Al-Zn-Mg-Cu-Zr alloy AA 7085 sheet was investigated by tensile testing at room temperature,transmission electron microscopy(TEM)and different...The influence of pre-stretching on quench sensitive effect of high strength Al-Zn-Mg-Cu-Zr alloy AA 7085 sheet was investigated by tensile testing at room temperature,transmission electron microscopy(TEM)and differential scanning calorimetry(DSC).The water-cooled and aged alloy exhibits higher strength than the air-cooled and aged alloy;2.5%pre-stretching of tensile deformation exerts little effect on strength of water-cooled and aged alloy but increases that of air-cooled and aged one,and therefore the yield strength reduction rate due to slow quenching decreases from about 3.8%to about 1.0%,reducing quench sensitive effect.For the air-cooled alloy,pre-stretching increases the sizes ofη'strengthening precipitates but also increases their quantity and the ratio of diameter to thickness,resulting in enhanced strengthening and higher strength after aging.The reason has been discussed based on microstructure examination by TEM and DSC.展开更多
To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead,it is vital to understand how the embedded structure(ES)affects the EFP forming performance.In this paper,the corresponding nu...To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead,it is vital to understand how the embedded structure(ES)affects the EFP forming performance.In this paper,the corresponding numerical investigation is focused on,in which the fluid-structure interaction(FSI)method and the experimental verification are used.Based on the obtained quantitative relations between the forming performance and a(the ratio of height to maximum radius of ES),an optimal design is further provided.The results indicate that:when the embedded structural length and width range 0.1e0.3D and 0.1e0.2D(D:diameter of EFP warhead)at a fixed volume,respectively,EFP forming velocity nearly keeps as a constant,1760 m/s;the height of ES has a dramatical effect on the propagating range of detonation wave,resulting in significant influence on the aerodynamic shape and length-to-diameter ratio of EFP;under the given constraints,the EFP length-diameter ratio can reach the optimal value2.76,when the height of ES is 0.22D.展开更多
A process of preparing ZnO voltage sensitive ceramics doped with some oxides by coprecipitation was described in the paper. The thermal properties of ZnO nanometer powders and the current voltage characteristics of ...A process of preparing ZnO voltage sensitive ceramics doped with some oxides by coprecipitation was described in the paper. The thermal properties of ZnO nanometer powders and the current voltage characteristics of the ceramics have been investigated. The results showed that the six additive ZnO powders with hexagonal system were homogeneous grain size distribution in microstructure, the optimal reaction pH is 6.90±0.05, the temperature for calcining and sintering was at about 500 ℃ and 1100 ℃, respectively. The powders were also examined by SEM, IR and XRD etc, and the effect of doping La 2O 3 on the electrical properties of ZnO varistor was investigated too.展开更多
The existing trajectory clustering （TRACLUS） is sensitive to the input parameters c and MinLns. The parameter value is changed a little, but cluster results are entirely different. Aiming at this vulnerability, a sh...The existing trajectory clustering （TRACLUS） is sensitive to the input parameters c and MinLns. The parameter value is changed a little, but cluster results are entirely different. Aiming at this vulnerability, a shielding parameters sensitivity trajectory cluster （SPSTC） algorithm is proposed which is insensitive to the input parameters. Firstly, some definitions about the core distance and reachable distance of line segment are presented, and then the algorithm generates cluster sorting according to the core dis- tance and reachable distance. Secondly, the reachable plots of line segment sets are constructed according to the cluster sorting and reachable distance. Thirdly, a parameterized sequence is extracted according to the reachable plot, and then the final trajectory cluster based on the parameterized sequence is acquired. The parameterized sequence represents the inner cluster structure of trajectory data. Experiments on real data sets and test data sets show that the SPSTC algorithm effectively reduces the sensitivity to the input parameters, meanwhile it can obtain the better quality of the trajectory cluster.展开更多
The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was e...The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was established and based on relevant analysis,the original model could be transformed by minimax method.Then,the optimal order quantity and production quantity influenced by service level constraint were analyzed and the boundary of optimal order quantity and production quantity was given.According to this boundary,the effective method and tactics were put forward to solve the transformed model.In case analysis,the optimal expected total cost of two-echelon inventory can be obtained and it was analyzed how service level constraint and safety factor influence the optimal expected total cost of two-echelon inventory.The results show that the optimal expected total cost of two-echelon inventory is constrained by the higher constraint between service level constraint and safety factor.展开更多
High purity and ultrafine DAAF(u-DAAF)is an emerging insensitive charge in initiators.Although there are many ways to obtain u-DAAF,developing a preparation method with stable operation,accurate control,good quality c...High purity and ultrafine DAAF(u-DAAF)is an emerging insensitive charge in initiators.Although there are many ways to obtain u-DAAF,developing a preparation method with stable operation,accurate control,good quality consistency,equipment miniaturization,and minimum manpower is an inevitable requirement to adapt to the current social technology development trend.Here reported is the microfluidic preparation of u-DAAF with tunable particle size by a passive swirling microreactor.Under the guidance of recrystallization growth kinetics and mixing behavior of fluids in the swirling microreactor,the key parameters(liquid flow rate,explosive concentration and crystallization temperature)were screened and optimized through screening experiments.Under the condition that no surfactant is added and only experimental parameters are controlled,the particle size of recrystallized DAAF can be adjusted from 98 nm to 785 nm,and the corresponding specific surface area is 8.45 m^(2)·g^(-1)to 1.33 m^(2)·g^(-1).In addition,the preparation method has good batch stability,high yield(90.8%-92.6%)and high purity(99.0%-99.4%),indicating a high practical application potential.Electric explosion derived flyer initiation tests demonstrate that the u-DAAF shows an initiation sensitivity much lower than that of the raw DAAF,and comparable to that of the refined DAAF by conventional spraying crystallization method.This study provides an efficient method to fabricate u-DAAF with narrow particle size distribution and high reproducibility as well as a theoretical reference for fabrication of other ultrafine explosives.展开更多
To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-...To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-Lys-Gly-D-Ala-D-Ala） was investigated by flow injection surface plasmon resonance （FI-SPR） and flow injection quartz crystal microbalance （FI-QCM）. To facilitate the formation of a compact vancomycin adsorbates layer with a uniform surface orientation, vancomycin molecules were attached onto a preformed alkanethiol self-assembled monolayer. By optimizing the conditions for the binding between Lys-Lys-Gly-D-Ala-D-Ala and vancomycin on the assembled chip, the detecting limit of Lys-Lys-Gly-D-Ala-D-Ala was greatly improved （reaching 0.5 ×10^- 6 mol/L or 7.5 × 10^-12 mol）. The equilibrium constant of the association of Lys-Lys-Gly-D-Ala-D-Ala with vancomycin was also obtained （KAds=5.0×10^4 L/tool）.展开更多
Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 ...Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.展开更多
Utilizing the first-principles calculation method of density functional theory,we investigate the electronic and mechanical properties of metal azides MN_(3)(M=Li,Na,Ag,Cu)and X(N_(3))_(2)(X=Cu,Hg,Pb),and explore thei...Utilizing the first-principles calculation method of density functional theory,we investigate the electronic and mechanical properties of metal azides MN_(3)(M=Li,Na,Ag,Cu)and X(N_(3))_(2)(X=Cu,Hg,Pb),and explore their correlation with impact sensitivity.The findings indicate that the impact sensitivities of the seven metal azides can be roughly ranked by considering both the band gap of the crystal and the relative atomic mass energy of the metal.Furthermore,it is suggested that the strong covalent nature of the metal-N in the upper valence band may be a significant factor contributing to the sensitivity observed in Cu(N_(3))_(2)and CuN_(3).The dominance of azide in the upper valence band while that of metal cations in lower conduction bands could explain why Hg(N_(3))_(2)and Pb(N_(3))_(2)exhibit higher sensitivity levels.Additionally,an analysis on mechanical properties reveals that the mechanical properties of metal azides will greatly affect their impact sensitivity,and the compression resistance is the most influential factor.展开更多
Objective Magnetoreception,the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation,remains a molecularly unresolved mystery in sensory biology.The putative m...Objective Magnetoreception,the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation,remains a molecularly unresolved mystery in sensory biology.The putative magnetoreceptor(MagR,previously known as IscA1)is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism;however,the functional diversity among its crossspecies homologs remains poorly understood.Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering.Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote,non-invasive magnetic modulation represents a crucial goal in this field with significant application potential.Therefore,this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities,screen for MagR-based magnetically sensitive morphology engineering pathways,and reveal the underlying molecular mechanisms.Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli(E.coli).To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins,we utilized high-throughput automated brightfield microscopic imaging and scanning electron microscopy(SEM).Furthermore,comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays,electron paramagnetic resonance(EPR)spectroscopy,ultraviolet-visible(UV-Vis)absorption,and circular dichroism(CD)spectroscopy.Additionally,100 mT static magnetic field(SMF)exposure experiments were conducted to assess magnetically tunable phenotypes,while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device(SQUID)magnetometer.Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation.From this comprehensive screen,two distinct morphological patterns were identified:hydra(Hydra vulgaris)MagR(hyMagR)promoted uniform cell elongation and filamentation,exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF.In contrast,pigeon(Columba livia)MagR(clMagR)induced only low-frequency,extreme filamentation(sporadically exceeding 80μm)with a relatively weaker magnetic morphological response.Mechanistically,our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation.Specifically,hyMagR preferentially binds ferrous iron(Fe^(2+)),whereas clMagR favors ferric iron(Fe^(3+))and forms more stable iron-sulfur clusters.Intriguingly,although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR,its cellular magnetic response was weaker.We hypothesize that the Fe^(2+)-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species(ROS)via the Fenton reaction.Exposure to an SMF synergizes with this primed redox state,triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation.Conclusion Our findings identify the Fe^(2+)/Fe^(3+)redox state as a critical determinant of MagRmediated morphological remodeling and magnetic responsiveness.This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications,and provides a plausible framework,which potentially combines intrinsic protein magnetism with redox-state modulation,for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.展开更多
AIM:Acute hypoxia can induce transient contraction of coronary arteries,leading to myocardial ischemia and even cardiac dysfunction.However,the precise regulatory mechanisms remain unclear.In this study,we ap-plied va...AIM:Acute hypoxia can induce transient contraction of coronary arteries,leading to myocardial ischemia and even cardiac dysfunction.However,the precise regulatory mechanisms remain unclear.In this study,we ap-plied various interventions to isolated porcine coronary arteries by modulating cytoplasmic calcium concentrations mediated by calcium channels on the plasma membrane and sarcoplasmic reticulum,aiming to investigate the relationship between hypoxic contraction and intracellular calcium levelsaswell as calcium sensitization effects.METHODS:Isolated rings of the porcine left anterior descending coronary artery served as the experimental model.Based on distinct intervention tar-gets,four core experimental groups were established.The specific grouping,sample size(n)for each group,and treat-ments were as follows:(1)nitric oxide(NO)-soluble guanylyl cyclase(sGC)pathway and energy metabolism intervention groups including control(n=5),nitric oxide synthase inhibitor nitro-L-arginine(NLA,10^(-4)mol/L;n=4 to 5),soluble guanylyl cyclase(sGC)antagonist 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one(ODQ,3×10^(-5)mol/L;n=5),endothe-lium-denuded(n=5),normal glucose incubation(n=3),and glucose-free incubation(n=3)groups;(2)calcium source intervention groups including normal calcium control(n=4),calcium-free incubation with 5×10^(-3)mol/L ethylene glycol tet-raacetic acid(EGTA;n=4),L-type calcium channel antagonist nifedipine(10^(-6)mol/L;n=5 to 7),non-selective cation channel inhibitor NiCl2(5×10^(-5)mol/L;n=5 to 7),sarcoplasmic reticulum Ca^(2+)-ATPase inhibitor thapsigargin(2×10^(-6)mol/L;n=5 to 7),and inositol trisphosphate(IP3)receptor antagonist 2-aminoethoxydiphenyl borate(2-APB,10^(-4)mol/L;n=5 to 7)groups;(3)myosin light chain kinase(MLCK)pathway intervention groups including control(n=4)and MLCK-specific inhibitor 1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride(ML-7,10^(-5)mol/L;n=6)groups;(4)myosin light chain phosphatase(MLCP)activity and endothelium-dependence intervention groups including endothelium-intact(n=4)and mechanically endothelium-denuded(n=6)groups.All arterial rings were pre-contracted with either U46619(3×10^(-7)mol/L)or KCl(6×10^(-2)mol/L)and then subjected to 10 minutes of hypoxia(95%N2+5%CO_(2)).Changes in vascular tension were continuously monitored and recorded using a multi-channel physiological signal acquisition system.Furthermore,combined with Western blotting,the phosphorylation level of myosin light chain(MLC)and the activity of MLCP were determined;the phosphorylation levels of MLC and MLCP were also compared between en-dothelium-intact and endothelium-denuded coronary arteries under hypoxic conditions.RESULTS:(1)Hypoxic constric-tion of porcine coronary arteries is dependent on the activation of endothelium-derived nitric oxide(NO)and sGCin vascu-lar smooth muscle cells.(2)Hypoxic contraction in porcine coronary arteries is independent of extracellular Ca^(2+)influx.(3)Hypoxic contraction in porcine coronary arteries does not rely on intracellular Ca^(2+)release from the sarcoplasmic reticu-lum.(4)Hypoxic contraction in porcine coronary arteries leads to inhibition of myosin light chain phosphatase activity,suggesting increased calcium sensitization in coronary artery smooth muscle.CONCLUSION:The mechanism under-lying acute hypoxia-induced vasoconstriction exhibits distinct characteristics:it does not rely on extracellular calcium influx mediated by plasma membrane calcium channels,nor is it associated with intracellular calcium mobilization from sar-coplasmic reticulum stores.Instead,it is mediated by a significant enhancement in calcium sensitivity regulated by myo-sin light chain phosphatase,a process referred to as calcium sensitization.展开更多
Microwave fracturing offers significant potential for efficient hard rock fragmentation.This study investigates real-time heating and fracture characteristics of ten granitoid minerals under 2 kW microwave irradiation...Microwave fracturing offers significant potential for efficient hard rock fragmentation.This study investigates real-time heating and fracture characteristics of ten granitoid minerals under 2 kW microwave irradiation for 3 min.Chlorite,amphibole,and altered plagioclase were identified as highly microwave-sensitive,exhibiting high mass and P-wave velocity decay,rapid heating rates(>2.5℃/s)and violent rupture.Mineral surface temperature non-uniformity,quantified by the coefficient of variation(V T),evolved through distinct increasing,decreasing,and stabilizing phases,reflecting shifts in dominance between heat accumulation and transfer.Temperature gradients revealed the spatial relationship between hotspots and rupture points,with shallow melting influencing surface temperature distribution.Undamaged minerals exhibited significant temperature gradient spatiotemporal variability but ultimately stabilizing.These results enable prediction of microwave heating behavior in hard rocks containing analogous minerals and enhance our understanding of microwave-induced weakening mechanisms.展开更多
This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation m...This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation method(DDM)with the linear multibody system transfer matrix method(linear MSTMM).The rigid-flexible coupled multibody system dynamics model of a tracked vehicle is established using the linear MSTMM and validated through the modal test.Building upon the existing DDM-based eigenvalue sensitivity analysis method within the linear MSTMM,the DDM is embedded into it to enable programmable and efficient computation of dynamic response sensitivities for mechanical systems.The proposed approach is used to quantitatively evaluate the sensitivities of both natural vibration characteristics(e.g.,natural frequencies and mode shapes)and transient dynamic responses of the tracked vehicle with respect to system parameters,successfully identifying critical structural parameters.Compared to conventional finite difference methods,the developed methodology eliminates sensitivity to perturbation step sizes.The contributions of this work lie in establishing a unified theoretical foundation and analysis framework for guiding dynamics optimization and design of mechanical systems,and extending the applicability of the linear MSTMM to sensitivity analysis of transient dynamic responses.展开更多
Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch dr...Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch drip irrigation emitters,focusing on the anti-clogging performance through the experiment,were investigated.The dynamic variations in the clogging characteristics of emitters,specifically were subjected to statistical analysis.The movement mechanism of emitter clogging and discharging sediment was studied.The effects of emitter structure and position factors on emitter clogging were analyzed.The results show that the pressure-compensated emitter exhibits superior anti-clogging perfor-mance,with a service life that is 227.8%greater than that of the labyrinth channel emitter.A single structural factor cannot completely evaluate the anti-clogging performance of emitters.All factors causing emitter clogging should be considered comprehensively.Emitters contain sensitive sediment prone to clogging,however,significant blockage occurs primarily when the sediment content is elevated.The discharge of sediment,denoted as V90,from the emitter is affected by the accumulative effect of clogged sediment.These results may offer valuable insights for the application and advancement of drip irrigation technology.展开更多
In order to analyze the influences of storage aging on the safety of typical elemental explosives,the aged cyclotrimethylene trinitramine(RDX)and cyclotetramethylene tetranitramine(HMX)were prepared by isothermal agin...In order to analyze the influences of storage aging on the safety of typical elemental explosives,the aged cyclotrimethylene trinitramine(RDX)and cyclotetramethylene tetranitramine(HMX)were prepared by isothermal aging tests.The reaction thresholds of aged RDX and HMX under any ignition probability were studied by Langlie-Optimal D method.The thermal decomposition characteristics of RDX and HMX after aging were analyzed by DSC and ARC.Experimental results showed that compared with unaged RDX and HMX,on the one hand,the critical impact energy and critical friction of RDX and HMX aged for 14,28,and 56 days are significantly reduced at an explosion probability of 50%,0.01%,and 0.0001%,respectively.With the increase of aging time,the mechanical sensitivity of RDX and HMX increases obviously.On the other hand,the initial decomposition temperature of RDX and HMX after 56 days of aging decreases,the decomposition heat decreases,the activation energy increases,and the reaction difficulty increases.展开更多
To scientifically evaluate the restoration performance of ancient city walls,Terahertz time-domain spectroscopy(THz-TDS)and infrared thermal imaging technology were applied to assess the Desheng Fortress(Ming Dynasty)...To scientifically evaluate the restoration performance of ancient city walls,Terahertz time-domain spectroscopy(THz-TDS)and infrared thermal imaging technology were applied to assess the Desheng Fortress(Ming Dynasty).Three representative sections were examined:adobe brick masonry repaired(Area 1),well-preserved original(Area 2),and layer-by-layer ramming repaired(Area 3).THz spectral data revealed significant differences between Area 1(time delay:3.72 ps;refractive index:2.224)and Area 2(time delay:3.02 ps;refractive index:2.107),while Area 3(time delay:3.12 ps;refractive index:2.098)demonstrated nearly identical THz spectral data to Area 2.Infrared thermal imaging also showed that the Area 3 restored by layer-by-layer ramming exhibited greater uniformity with fewer instances of cracks,capillary phenomena,or biological diseases.The proposed point-surface integrated evaluation methodology synergistically combines infrared thermography mapping of heritage surfaces with THz spectral datasets acquired through in-situ micro-sampling,enabling quantitative restoration assessment and providing a novel approach for scientifically validating traditional conservation techniques.展开更多
Hepatocellular carcinoma(HCC),which is essentially primary liver cancer,is closely related to CD8^(+)T cell immune infiltration and immune suppression.We constructed a CD8^(+)T cells related risk score model to predic...Hepatocellular carcinoma(HCC),which is essentially primary liver cancer,is closely related to CD8^(+)T cell immune infiltration and immune suppression.We constructed a CD8^(+)T cells related risk score model to predict the prognosis of HCC patients and provided therapeutic guidance based on the risk score.Using integrated bulk RNA sequencing(RNA-seq)and single-cell RNA sequencing(scRNA-seq)datasets,we identified stable CD8^(+)T cell signatures.Based on these signatures,a 3-gene risk score model,comprised of KLRB1,RGS 2,and TNFRSF1B was constructed.The risk score model was well validated through an independent external validation cohort.We divided patients into high-risk and low-risk groups according to the risk score and compared the differences in immune microenvironment between these two groups.Compared with low-risk patients,high-risk patients have higher M2-type macrophage content(P<0.0001)and lower CD8^(+)T cells infiltration(P<0.0001).High-risk patients predict worse response to immunotherapy treatment than low-risk patients(P<0.01).Drug sensitivity analysis shows that PI3K-β inhibitor AZD6482 and TGFβRII inhibitor SB505124 may be suitable therapies for high-risk patients,while the IGF-1R inhibitor BMS-754807 or the novel pyrimidine-based anti-tumor metabolic drug Gemcitabine could be potential therapeutic choices for low-risk patients.Moreover,expression of these 3-gene model was verified by immunohistochemistry.In summary,the establishment and validation of a CD8^(+)T cell-derived risk model can more accurately predict the prognosis of HCC patients and guide the construction of personalized treatment plans.展开更多
Potassium-calcium activates channel subfamily N member 3(KCNN3/SK3/KCa2.3)is involved in regulating cellular calcium signaling,muscle contraction and neurotransmitter release.Dysregulation of the KCNN3 channel is asso...Potassium-calcium activates channel subfamily N member 3(KCNN3/SK3/KCa2.3)is involved in regulating cellular calcium signaling,muscle contraction and neurotransmitter release.Dysregulation of the KCNN3 channel is associated with the development of various tumors.We use bioinformatics analysis to identify whether KCNN3 regulates the occurrence and development of stomach adenocarcinoma(STAD)as a prognostic target.By analyzing the Human Protein Atlas(HPA)database and The Cancer Genome Atlas(TCGA)database,we found that the protein and mRNA levels of KCNN3 were dramatically reduced in STAD,and TCGA database showed that KCNN3 significantly correlated with the prognosis and clinical features of STAD.In addition,we found that high expression of KCNN3 in STAD reduced the IC 50 of several drugs in STAD cells,suggesting that high expression of KCNN3 correlated with the drug sensitivity of STAD.To investigate the underlying biological mechanism,we identified a potential KCNN3 interaction factor,tumor necrosis factor receptor superfamily member 7(CD27/TNFRSF7),which is expressed at low levels in STAD.RT-qPCR and Western blotting confirmed that KCNN3 and CD27 positively correlated with each other at protein and mRNA levels,and co-immunoprecipitation and immunofluorescence experiments confirmed that the two proteins interact and colocalize in the cytoplasm.Moreover,we confirmed the inhibitory effect of KCNN3 on the proliferation,migration and invasion of human STAD cells in vitro and in vivo through subcutaneous tumorigenesis and cellular experiments.Furthermore,GO/KEGG enrichment analysis showed that KCNN3 was enriched in signaling pathways regulating the immune response and calcium or metal ion transport.Lastly,we verified through cell co-culture,RT-qPCR and CCK8 assays that high expression of KCNN3 can promote the increase of T cell activating factor and the killing effect of T cells on STAD cells.Therefore,our results suggest that KCNN3 is a potential inhibitory factor affecting the occurrence and progression of STAD.展开更多
文摘To investigate the mechanisms of apigenin(API)and proanthocyanidins(PC)in soothing sensitive skin(SS),a mast cell degranulation model was established by stimulating RBL-2H3 cells with the calcium ionophore A23187.Based on the combinatorial experiments,it was found that when API and PC were combined at the molar ratios of 4∶1 and 2∶1,they exhibited the antagonistic effects on histamine release(combination index CI>1);when they are combined at the molar ratios of 1∶1,1∶2 or 1∶4,they showed the synergistic effects on histamine release(CI<1).Among them,the combination of API and PC at a molar ratio of 1∶1 showed the better potent synergistic antihistamine release effect(CI=0.70).Histamine is a hallmark of the mast cell degranulation,consequently,the combination of API and PC at a molar ratio of 1∶1 yields the better efficiency in inhibiting the mast cell degranulation with the lowest IC_(50)value.Compared to the utilization of API or PC alone,the IC_(50)value was reduced by 11.150 and 6.503μmol/L,respectively.Compared to the positive control paeonol(PA),the treatment with the combination significantly reduced theβ-hex secretion,decreased the F-actin cytoskeleton rearrangement,and markedly suppressed the release of TNF-α,IL-4,and MCP-1.Further studies on the signaling pathways related to the mast cell degranulation indicated that the combination effectively inhibited the intracellular Ca^(2+)influx and significantly suppressed the phosphorylation of calmodulin-dependent protein kinase(CaMK)and phospholipase C/protein kinase C(PLC/PKC).In summary,the combination of API and PC at a molar ratio of 1∶1 exhibited the better synergistic antagonistic effect on the histamine release,inhibited the mast cell degranulation model activation by reducing Ca^(2+)influx and inhibiting the activation of Ca^(2+)/CaMK and PLC/PKC pathways,stabilized the cell membranes,regulated the inflammatory factor secretion,and exerted an effect in alleviating sensitive skin.
基金Project(AA17202007) supported by the Special Funding for Innovation-Driven Development of Guangxi Province,China。
文摘The influence of pre-stretching on quench sensitive effect of high strength Al-Zn-Mg-Cu-Zr alloy AA 7085 sheet was investigated by tensile testing at room temperature,transmission electron microscopy(TEM)and differential scanning calorimetry(DSC).The water-cooled and aged alloy exhibits higher strength than the air-cooled and aged alloy;2.5%pre-stretching of tensile deformation exerts little effect on strength of water-cooled and aged alloy but increases that of air-cooled and aged one,and therefore the yield strength reduction rate due to slow quenching decreases from about 3.8%to about 1.0%,reducing quench sensitive effect.For the air-cooled alloy,pre-stretching increases the sizes ofη'strengthening precipitates but also increases their quantity and the ratio of diameter to thickness,resulting in enhanced strengthening and higher strength after aging.The reason has been discussed based on microstructure examination by TEM and DSC.
基金funded by the National Natural Science Foundation of China under No. 11102088Fundamental Research Funds for the Central Universities under No. 30915118821funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China under No. 20133219110019
文摘To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead,it is vital to understand how the embedded structure(ES)affects the EFP forming performance.In this paper,the corresponding numerical investigation is focused on,in which the fluid-structure interaction(FSI)method and the experimental verification are used.Based on the obtained quantitative relations between the forming performance and a(the ratio of height to maximum radius of ES),an optimal design is further provided.The results indicate that:when the embedded structural length and width range 0.1e0.3D and 0.1e0.2D(D:diameter of EFP warhead)at a fixed volume,respectively,EFP forming velocity nearly keeps as a constant,1760 m/s;the height of ES has a dramatical effect on the propagating range of detonation wave,resulting in significant influence on the aerodynamic shape and length-to-diameter ratio of EFP;under the given constraints,the EFP length-diameter ratio can reach the optimal value2.76,when the height of ES is 0.22D.
文摘A process of preparing ZnO voltage sensitive ceramics doped with some oxides by coprecipitation was described in the paper. The thermal properties of ZnO nanometer powders and the current voltage characteristics of the ceramics have been investigated. The results showed that the six additive ZnO powders with hexagonal system were homogeneous grain size distribution in microstructure, the optimal reaction pH is 6.90±0.05, the temperature for calcining and sintering was at about 500 ℃ and 1100 ℃, respectively. The powders were also examined by SEM, IR and XRD etc, and the effect of doping La 2O 3 on the electrical properties of ZnO varistor was investigated too.
基金supported by the National High Technology Research and Development Program of China(863 Program)(2007AA01Z404)the Funding of Jiangsu Provincial Innovation Program for Graduate Education(CXLX110206)
文摘The existing trajectory clustering （TRACLUS） is sensitive to the input parameters c and MinLns. The parameter value is changed a little, but cluster results are entirely different. Aiming at this vulnerability, a shielding parameters sensitivity trajectory cluster （SPSTC） algorithm is proposed which is insensitive to the input parameters. Firstly, some definitions about the core distance and reachable distance of line segment are presented, and then the algorithm generates cluster sorting according to the core dis- tance and reachable distance. Secondly, the reachable plots of line segment sets are constructed according to the cluster sorting and reachable distance. Thirdly, a parameterized sequence is extracted according to the reachable plot, and then the final trajectory cluster based on the parameterized sequence is acquired. The parameterized sequence represents the inner cluster structure of trajectory data. Experiments on real data sets and test data sets show that the SPSTC algorithm effectively reduces the sensitivity to the input parameters, meanwhile it can obtain the better quality of the trajectory cluster.
基金Project(71102174,71372019)supported by the National Natural Science Foundation of ChinaProject(9123028)supported by the Beijing Natural Science Foundation of China+3 种基金Project(20111101120019)supported by the Specialized Research Fund for Doctoral Program of Higher Education of ChinaProject(11JGC106)supported by the Beijing Philosophy&Social Science Foundation of ChinaProjects(NCET-10-0048,NCET-10-0043)supported by the Program for New Century Excellent Talents in University of ChinaProject(2010YC1307)supported by Excellent Young Teacher in Beijing Institute of Technology of China
文摘The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was established and based on relevant analysis,the original model could be transformed by minimax method.Then,the optimal order quantity and production quantity influenced by service level constraint were analyzed and the boundary of optimal order quantity and production quantity was given.According to this boundary,the effective method and tactics were put forward to solve the transformed model.In case analysis,the optimal expected total cost of two-echelon inventory can be obtained and it was analyzed how service level constraint and safety factor influence the optimal expected total cost of two-echelon inventory.The results show that the optimal expected total cost of two-echelon inventory is constrained by the higher constraint between service level constraint and safety factor.
基金the National Natural Science Foundation of China (Grant No.22105184)Research Fund of SWUST for PhD (Grant No.22zx7175)+1 种基金Sichuan Science and Technology Program (Grant No.2019ZDZX0013)Institute of Chemical Materials Program (Grant No.SXK-2022-03)for financial support。
文摘High purity and ultrafine DAAF(u-DAAF)is an emerging insensitive charge in initiators.Although there are many ways to obtain u-DAAF,developing a preparation method with stable operation,accurate control,good quality consistency,equipment miniaturization,and minimum manpower is an inevitable requirement to adapt to the current social technology development trend.Here reported is the microfluidic preparation of u-DAAF with tunable particle size by a passive swirling microreactor.Under the guidance of recrystallization growth kinetics and mixing behavior of fluids in the swirling microreactor,the key parameters(liquid flow rate,explosive concentration and crystallization temperature)were screened and optimized through screening experiments.Under the condition that no surfactant is added and only experimental parameters are controlled,the particle size of recrystallized DAAF can be adjusted from 98 nm to 785 nm,and the corresponding specific surface area is 8.45 m^(2)·g^(-1)to 1.33 m^(2)·g^(-1).In addition,the preparation method has good batch stability,high yield(90.8%-92.6%)and high purity(99.0%-99.4%),indicating a high practical application potential.Electric explosion derived flyer initiation tests demonstrate that the u-DAAF shows an initiation sensitivity much lower than that of the raw DAAF,and comparable to that of the refined DAAF by conventional spraying crystallization method.This study provides an efficient method to fabricate u-DAAF with narrow particle size distribution and high reproducibility as well as a theoretical reference for fabrication of other ultrafine explosives.
基金Projects(20773165,20876179) supported by the National Natural Science Foundation of ChinaProject(09JJ1002) supported by the Hunan Provincial Natural Science Foundation,China+1 种基金Project(NCET-07-0865) for New Century Excellent Talents in Chinese UniversityProject(2007AA022006) supported by the National High Technology Research and Development Program of China
文摘To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-Lys-Gly-D-Ala-D-Ala） was investigated by flow injection surface plasmon resonance （FI-SPR） and flow injection quartz crystal microbalance （FI-QCM）. To facilitate the formation of a compact vancomycin adsorbates layer with a uniform surface orientation, vancomycin molecules were attached onto a preformed alkanethiol self-assembled monolayer. By optimizing the conditions for the binding between Lys-Lys-Gly-D-Ala-D-Ala and vancomycin on the assembled chip, the detecting limit of Lys-Lys-Gly-D-Ala-D-Ala was greatly improved （reaching 0.5 ×10^- 6 mol/L or 7.5 × 10^-12 mol）. The equilibrium constant of the association of Lys-Lys-Gly-D-Ala-D-Ala with vancomycin was also obtained （KAds=5.0×10^4 L/tool）.
基金supported by the National Natural Science Foundation of China(No.22090050,No.22090052,No.22176180)National Basic Research Program of China(No.2021YFA1200400)+1 种基金the Natural Science Foundation of Hubei Province(No.2024AFA001)Shenzhen Science and Technology Program(No.JCYJ20220530162406014)。
文摘Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.
文摘Utilizing the first-principles calculation method of density functional theory,we investigate the electronic and mechanical properties of metal azides MN_(3)(M=Li,Na,Ag,Cu)and X(N_(3))_(2)(X=Cu,Hg,Pb),and explore their correlation with impact sensitivity.The findings indicate that the impact sensitivities of the seven metal azides can be roughly ranked by considering both the band gap of the crystal and the relative atomic mass energy of the metal.Furthermore,it is suggested that the strong covalent nature of the metal-N in the upper valence band may be a significant factor contributing to the sensitivity observed in Cu(N_(3))_(2)and CuN_(3).The dominance of azide in the upper valence band while that of metal cations in lower conduction bands could explain why Hg(N_(3))_(2)and Pb(N_(3))_(2)exhibit higher sensitivity levels.Additionally,an analysis on mechanical properties reveals that the mechanical properties of metal azides will greatly affect their impact sensitivity,and the compression resistance is the most influential factor.
文摘Objective Magnetoreception,the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation,remains a molecularly unresolved mystery in sensory biology.The putative magnetoreceptor(MagR,previously known as IscA1)is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism;however,the functional diversity among its crossspecies homologs remains poorly understood.Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering.Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote,non-invasive magnetic modulation represents a crucial goal in this field with significant application potential.Therefore,this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities,screen for MagR-based magnetically sensitive morphology engineering pathways,and reveal the underlying molecular mechanisms.Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli(E.coli).To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins,we utilized high-throughput automated brightfield microscopic imaging and scanning electron microscopy(SEM).Furthermore,comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays,electron paramagnetic resonance(EPR)spectroscopy,ultraviolet-visible(UV-Vis)absorption,and circular dichroism(CD)spectroscopy.Additionally,100 mT static magnetic field(SMF)exposure experiments were conducted to assess magnetically tunable phenotypes,while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device(SQUID)magnetometer.Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation.From this comprehensive screen,two distinct morphological patterns were identified:hydra(Hydra vulgaris)MagR(hyMagR)promoted uniform cell elongation and filamentation,exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF.In contrast,pigeon(Columba livia)MagR(clMagR)induced only low-frequency,extreme filamentation(sporadically exceeding 80μm)with a relatively weaker magnetic morphological response.Mechanistically,our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation.Specifically,hyMagR preferentially binds ferrous iron(Fe^(2+)),whereas clMagR favors ferric iron(Fe^(3+))and forms more stable iron-sulfur clusters.Intriguingly,although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR,its cellular magnetic response was weaker.We hypothesize that the Fe^(2+)-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species(ROS)via the Fenton reaction.Exposure to an SMF synergizes with this primed redox state,triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation.Conclusion Our findings identify the Fe^(2+)/Fe^(3+)redox state as a critical determinant of MagRmediated morphological remodeling and magnetic responsiveness.This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications,and provides a plausible framework,which potentially combines intrinsic protein magnetism with redox-state modulation,for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
基金Supported by the Zhejiang Provincial Natural Science Foundation(No.LYY22H310001)。
文摘AIM:Acute hypoxia can induce transient contraction of coronary arteries,leading to myocardial ischemia and even cardiac dysfunction.However,the precise regulatory mechanisms remain unclear.In this study,we ap-plied various interventions to isolated porcine coronary arteries by modulating cytoplasmic calcium concentrations mediated by calcium channels on the plasma membrane and sarcoplasmic reticulum,aiming to investigate the relationship between hypoxic contraction and intracellular calcium levelsaswell as calcium sensitization effects.METHODS:Isolated rings of the porcine left anterior descending coronary artery served as the experimental model.Based on distinct intervention tar-gets,four core experimental groups were established.The specific grouping,sample size(n)for each group,and treat-ments were as follows:(1)nitric oxide(NO)-soluble guanylyl cyclase(sGC)pathway and energy metabolism intervention groups including control(n=5),nitric oxide synthase inhibitor nitro-L-arginine(NLA,10^(-4)mol/L;n=4 to 5),soluble guanylyl cyclase(sGC)antagonist 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one(ODQ,3×10^(-5)mol/L;n=5),endothe-lium-denuded(n=5),normal glucose incubation(n=3),and glucose-free incubation(n=3)groups;(2)calcium source intervention groups including normal calcium control(n=4),calcium-free incubation with 5×10^(-3)mol/L ethylene glycol tet-raacetic acid(EGTA;n=4),L-type calcium channel antagonist nifedipine(10^(-6)mol/L;n=5 to 7),non-selective cation channel inhibitor NiCl2(5×10^(-5)mol/L;n=5 to 7),sarcoplasmic reticulum Ca^(2+)-ATPase inhibitor thapsigargin(2×10^(-6)mol/L;n=5 to 7),and inositol trisphosphate(IP3)receptor antagonist 2-aminoethoxydiphenyl borate(2-APB,10^(-4)mol/L;n=5 to 7)groups;(3)myosin light chain kinase(MLCK)pathway intervention groups including control(n=4)and MLCK-specific inhibitor 1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride(ML-7,10^(-5)mol/L;n=6)groups;(4)myosin light chain phosphatase(MLCP)activity and endothelium-dependence intervention groups including endothelium-intact(n=4)and mechanically endothelium-denuded(n=6)groups.All arterial rings were pre-contracted with either U46619(3×10^(-7)mol/L)or KCl(6×10^(-2)mol/L)and then subjected to 10 minutes of hypoxia(95%N2+5%CO_(2)).Changes in vascular tension were continuously monitored and recorded using a multi-channel physiological signal acquisition system.Furthermore,combined with Western blotting,the phosphorylation level of myosin light chain(MLC)and the activity of MLCP were determined;the phosphorylation levels of MLC and MLCP were also compared between en-dothelium-intact and endothelium-denuded coronary arteries under hypoxic conditions.RESULTS:(1)Hypoxic constric-tion of porcine coronary arteries is dependent on the activation of endothelium-derived nitric oxide(NO)and sGCin vascu-lar smooth muscle cells.(2)Hypoxic contraction in porcine coronary arteries is independent of extracellular Ca^(2+)influx.(3)Hypoxic contraction in porcine coronary arteries does not rely on intracellular Ca^(2+)release from the sarcoplasmic reticu-lum.(4)Hypoxic contraction in porcine coronary arteries leads to inhibition of myosin light chain phosphatase activity,suggesting increased calcium sensitization in coronary artery smooth muscle.CONCLUSION:The mechanism under-lying acute hypoxia-induced vasoconstriction exhibits distinct characteristics:it does not rely on extracellular calcium influx mediated by plasma membrane calcium channels,nor is it associated with intracellular calcium mobilization from sar-coplasmic reticulum stores.Instead,it is mediated by a significant enhancement in calcium sensitivity regulated by myo-sin light chain phosphatase,a process referred to as calcium sensitization.
基金Projects(52225403,42407249)supported by the National Natural Science Foundation of ChinaProject(2023 YFF 0615401)supported by the National Key Research and Development Program of ChinaProjects(2025T180507,2024M762221)supported by China Postdoctoral Science Foundation。
文摘Microwave fracturing offers significant potential for efficient hard rock fragmentation.This study investigates real-time heating and fracture characteristics of ten granitoid minerals under 2 kW microwave irradiation for 3 min.Chlorite,amphibole,and altered plagioclase were identified as highly microwave-sensitive,exhibiting high mass and P-wave velocity decay,rapid heating rates(>2.5℃/s)and violent rupture.Mineral surface temperature non-uniformity,quantified by the coefficient of variation(V T),evolved through distinct increasing,decreasing,and stabilizing phases,reflecting shifts in dominance between heat accumulation and transfer.Temperature gradients revealed the spatial relationship between hotspots and rupture points,with shallow melting influencing surface temperature distribution.Undamaged minerals exhibited significant temperature gradient spatiotemporal variability but ultimately stabilizing.These results enable prediction of microwave heating behavior in hard rocks containing analogous minerals and enhance our understanding of microwave-induced weakening mechanisms.
基金supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20241443)the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2024ZB072)the National Natural Science Foundation of China(Grant No.92266201).
文摘This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation method(DDM)with the linear multibody system transfer matrix method(linear MSTMM).The rigid-flexible coupled multibody system dynamics model of a tracked vehicle is established using the linear MSTMM and validated through the modal test.Building upon the existing DDM-based eigenvalue sensitivity analysis method within the linear MSTMM,the DDM is embedded into it to enable programmable and efficient computation of dynamic response sensitivities for mechanical systems.The proposed approach is used to quantitatively evaluate the sensitivities of both natural vibration characteristics(e.g.,natural frequencies and mode shapes)and transient dynamic responses of the tracked vehicle with respect to system parameters,successfully identifying critical structural parameters.Compared to conventional finite difference methods,the developed methodology eliminates sensitivity to perturbation step sizes.The contributions of this work lie in establishing a unified theoretical foundation and analysis framework for guiding dynamics optimization and design of mechanical systems,and extending the applicability of the linear MSTMM to sensitivity analysis of transient dynamic responses.
基金National Natural Science Foundation of China(52269011,52469008)。
文摘Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch drip irrigation emitters,focusing on the anti-clogging performance through the experiment,were investigated.The dynamic variations in the clogging characteristics of emitters,specifically were subjected to statistical analysis.The movement mechanism of emitter clogging and discharging sediment was studied.The effects of emitter structure and position factors on emitter clogging were analyzed.The results show that the pressure-compensated emitter exhibits superior anti-clogging perfor-mance,with a service life that is 227.8%greater than that of the labyrinth channel emitter.A single structural factor cannot completely evaluate the anti-clogging performance of emitters.All factors causing emitter clogging should be considered comprehensively.Emitters contain sensitive sediment prone to clogging,however,significant blockage occurs primarily when the sediment content is elevated.The discharge of sediment,denoted as V90,from the emitter is affected by the accumulative effect of clogged sediment.These results may offer valuable insights for the application and advancement of drip irrigation technology.
基金supported by the National Key Laboratory of Energetic Materials, China (Grant No. 2023-LB-036-09).
文摘In order to analyze the influences of storage aging on the safety of typical elemental explosives,the aged cyclotrimethylene trinitramine(RDX)and cyclotetramethylene tetranitramine(HMX)were prepared by isothermal aging tests.The reaction thresholds of aged RDX and HMX under any ignition probability were studied by Langlie-Optimal D method.The thermal decomposition characteristics of RDX and HMX after aging were analyzed by DSC and ARC.Experimental results showed that compared with unaged RDX and HMX,on the one hand,the critical impact energy and critical friction of RDX and HMX aged for 14,28,and 56 days are significantly reduced at an explosion probability of 50%,0.01%,and 0.0001%,respectively.With the increase of aging time,the mechanical sensitivity of RDX and HMX increases obviously.On the other hand,the initial decomposition temperature of RDX and HMX after 56 days of aging decreases,the decomposition heat decreases,the activation energy increases,and the reaction difficulty increases.
文摘To scientifically evaluate the restoration performance of ancient city walls,Terahertz time-domain spectroscopy(THz-TDS)and infrared thermal imaging technology were applied to assess the Desheng Fortress(Ming Dynasty).Three representative sections were examined:adobe brick masonry repaired(Area 1),well-preserved original(Area 2),and layer-by-layer ramming repaired(Area 3).THz spectral data revealed significant differences between Area 1(time delay:3.72 ps;refractive index:2.224)and Area 2(time delay:3.02 ps;refractive index:2.107),while Area 3(time delay:3.12 ps;refractive index:2.098)demonstrated nearly identical THz spectral data to Area 2.Infrared thermal imaging also showed that the Area 3 restored by layer-by-layer ramming exhibited greater uniformity with fewer instances of cracks,capillary phenomena,or biological diseases.The proposed point-surface integrated evaluation methodology synergistically combines infrared thermography mapping of heritage surfaces with THz spectral datasets acquired through in-situ micro-sampling,enabling quantitative restoration assessment and providing a novel approach for scientifically validating traditional conservation techniques.
基金国家自然科学基金项目(No.81902513)山西省应用基础研究计划项目(No.202303021211114 and 202103021224228)山西省高等教育百亿工程“科技引导”专项(No.BYJL047)资助。
文摘Hepatocellular carcinoma(HCC),which is essentially primary liver cancer,is closely related to CD8^(+)T cell immune infiltration and immune suppression.We constructed a CD8^(+)T cells related risk score model to predict the prognosis of HCC patients and provided therapeutic guidance based on the risk score.Using integrated bulk RNA sequencing(RNA-seq)and single-cell RNA sequencing(scRNA-seq)datasets,we identified stable CD8^(+)T cell signatures.Based on these signatures,a 3-gene risk score model,comprised of KLRB1,RGS 2,and TNFRSF1B was constructed.The risk score model was well validated through an independent external validation cohort.We divided patients into high-risk and low-risk groups according to the risk score and compared the differences in immune microenvironment between these two groups.Compared with low-risk patients,high-risk patients have higher M2-type macrophage content(P<0.0001)and lower CD8^(+)T cells infiltration(P<0.0001).High-risk patients predict worse response to immunotherapy treatment than low-risk patients(P<0.01).Drug sensitivity analysis shows that PI3K-β inhibitor AZD6482 and TGFβRII inhibitor SB505124 may be suitable therapies for high-risk patients,while the IGF-1R inhibitor BMS-754807 or the novel pyrimidine-based anti-tumor metabolic drug Gemcitabine could be potential therapeutic choices for low-risk patients.Moreover,expression of these 3-gene model was verified by immunohistochemistry.In summary,the establishment and validation of a CD8^(+)T cell-derived risk model can more accurately predict the prognosis of HCC patients and guide the construction of personalized treatment plans.
文摘Potassium-calcium activates channel subfamily N member 3(KCNN3/SK3/KCa2.3)is involved in regulating cellular calcium signaling,muscle contraction and neurotransmitter release.Dysregulation of the KCNN3 channel is associated with the development of various tumors.We use bioinformatics analysis to identify whether KCNN3 regulates the occurrence and development of stomach adenocarcinoma(STAD)as a prognostic target.By analyzing the Human Protein Atlas(HPA)database and The Cancer Genome Atlas(TCGA)database,we found that the protein and mRNA levels of KCNN3 were dramatically reduced in STAD,and TCGA database showed that KCNN3 significantly correlated with the prognosis and clinical features of STAD.In addition,we found that high expression of KCNN3 in STAD reduced the IC 50 of several drugs in STAD cells,suggesting that high expression of KCNN3 correlated with the drug sensitivity of STAD.To investigate the underlying biological mechanism,we identified a potential KCNN3 interaction factor,tumor necrosis factor receptor superfamily member 7(CD27/TNFRSF7),which is expressed at low levels in STAD.RT-qPCR and Western blotting confirmed that KCNN3 and CD27 positively correlated with each other at protein and mRNA levels,and co-immunoprecipitation and immunofluorescence experiments confirmed that the two proteins interact and colocalize in the cytoplasm.Moreover,we confirmed the inhibitory effect of KCNN3 on the proliferation,migration and invasion of human STAD cells in vitro and in vivo through subcutaneous tumorigenesis and cellular experiments.Furthermore,GO/KEGG enrichment analysis showed that KCNN3 was enriched in signaling pathways regulating the immune response and calcium or metal ion transport.Lastly,we verified through cell co-culture,RT-qPCR and CCK8 assays that high expression of KCNN3 can promote the increase of T cell activating factor and the killing effect of T cells on STAD cells.Therefore,our results suggest that KCNN3 is a potential inhibitory factor affecting the occurrence and progression of STAD.
