The utilization of Inlet Guide Vane (IGV) plays a key factor in affecting the instability evolution. Existing literature mainly focuses on the effect of IGV on instability inception that occurs in the rotor region. Ho...The utilization of Inlet Guide Vane (IGV) plays a key factor in affecting the instability evolution. Existing literature mainly focuses on the effect of IGV on instability inception that occurs in the rotor region. However, with the emergence of compressor instability starting from the stator region, the mechanism of various instability inceptions that occurs in different blade rows due to the change of IGV angles should be further examined. In this study, experiments were focused on three types of instability inceptions observed previously in a 1.5-stage axial flow compressor. To analyze the conversion of stall evolutions, the compressor rotating speed was set to 17 160 r/min, at which both the blade loading in the stator hub region and rotor tip region were close to the critical value before final compressor stall. Meanwhile, the dynamic test points with high-response were placed to monitor the pressures both at the stator trailing edges and rotor tips. The results indicate that the variation of reaction determines the region where initial instability occurs. Indeed, negative pre-rotation of the inlet guide vane leads to high-reaction, initiating stall disturbance from the rotor region. Positive pre-rotation results in low-reaction, initiating stall disturbance from the stator region. Furthermore, the type of instability evolution is affected by the radial loading distribution under different IGV angles. Specifically, a spike-type inception occurs at the rotor blade tip with a large angle of attack at the rotor inlet (−2°, −4° and −6°). Meanwhile, the critical total pressure ratio at the rotor tip is 1.40 near stall. As the angle of attack decreases, the stator blade loading reaches its critical boundary, with a value of approximately 1.35. At this moment, if the rotor tip maintains high blade loading similar to the stator hub, the partial surge occurs (0° and +2°);otherwise, the hub instability occurs (+4° and +6°).展开更多
In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-bindi...In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-binding Hamiltonian including onsite Coulomb repulsion U,V,and spin-orbital couplingλ.The program is applied to Ba_(2)MgReO_(6)to fgure out the mechanism of structural instability and magnetic ordering.A comprehensive quadrupole phase diagram versus U and V withλ=0.28 eV is calculated.Our results demonstrate that the easy-plane anisotropy and the intersite Coulomb repulsion V must be considered to remove the orbital frustration.The increase of V to>20 meV would arrange quadrupole Q_(x^(2)-y^(2))antiparallelly,accompanied by small parallel Q_(3z)^(2)-r^(2),and stabilize Ba_(2)MgReO_(6)into the body-centered tetragonal structure.Such antiparallel Q_(x^(2)-y^(2))provides a new mechanism for the Dzyaloshinskii-Moriya interaction and gives rise to the canted antiferromagnetic(CAF)state along the[110]axis.Moreover,sizable octupoles such as O_(21)^(31),O_(21)^(33),O_(21)^(34)and O_(21)^(36)are discovered for the frst time in the CAF state.Our study not only provides a comprehensive understanding of the experimental results in Ba_(2)MgReO_(6),but also serves as a general and useful tool for the study of multipole physics in 5d compounds.展开更多
The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the pla...The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the plasma acceleration phase,shorter wavelengths lead to more efficien coupling between the laser and the kinetic energy of the implosion fluid Under the condition that the laser energy coupled to the implosion flui is constant,the ARTI growth rate decreases as the laser wavelength moves toward the extreme ultraviolet band,reaching its minimum value near λ=65 nm,and when the laser wavelength continuously moves toward the X-ray band,the ARTI growth rate increases rapidly.It is found that the results deviate from the theoretical ARTI growth rate.As the laser intensity benchmark increases,the position of the minimum ARTI growth rate shifts toward shorter wavelengths.As the initial sinusoidal perturbation wavenumber decreases,the position of the minimum ARTI growth rate shifts toward longer wavelengths.We believe that the conclusions drawn from the present simulations and analysis will help provide a better understanding of the ICF process and improve the theory of ARTI growth.展开更多
Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,ins...Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,insufficient doping of the ablator material can result in highenergy X-ray preheat,which may trigger the development of a classical-like Rayleigh-Taylor instability(RTI)at the fuel-ablator interface.In implosion experiments at the Shenguang 100 kJ-level laser facility,the primary source of perturbation is the roughness of the inner DT ice interface.In this study,we propose an analytical model to describe the feed-out process of the initial roughness of the inner DT ice interface.The perturbation amplitude derived from this model serves as the initial seed for the late-time RTI during the acceleration phase.Our findings confirm the presence of classical-like RTI at the fuel-ablator interface.Numerical simulations conducted using a radiation hydrodynamic code validate the proposed analytical model and demonstrate the existence of a peak mode number in both the feed-out process and the classical-like RTI.It provides an alternative bridge between the current target fabrication limitations and the unexpected implosion performance.展开更多
Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming.Although there exist diverse bi-stable structures capable of snap-throug...Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming.Although there exist diverse bi-stable structures capable of snap-through instability,it is still difficult for a structure with high slenderness to undergo the axial snap-through instability with a large stroke.Here,an elastic structure with high slenderness is simply constructed by a finite number of identical,conventional bi-stable units with relatively low slenderness in series connection.For realizing the axial snap-through instability with a large stroke,common scissors mechanisms are further introduced as rigid constraints to guarantee the synchronous snap-through instability of these bi-stable units.The global feature of the large-stroke snap-through instability realized here is robust and even insusceptible to the local out-of-synchronization of individual units.The present design provides a simple and feasible way to achieve the large-stroke snap-through instability of slender structures,which is expected to be particularly useful for state switching and energy transforming in narrow spaces.展开更多
Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ig...Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs.展开更多
We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of plana...We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of planar flow fields where the transverse direction exhibits vanishing but non-zero velocity components,such as a disturbed onedimensional(1D)steady shock wave,we conduct a formal asymptotic analysis for the Euler system and associated numerical methods.This analysis aims to illustrate the discrepancies among various low-dissipative numerical algorithms.Furthermore,a numerical stability analysis of steady shock is undertaken to identify the key factors underlying shock-stable algorithms.To verify the stability mechanism,a consistent,low-dissipation,and shock-stable HLLC-type Riemann solver is presented.展开更多
A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to...A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to study the effect of suspended particles on the growth rate of KH instability.For dusty gases with negligible volume fraction of heavy particles and small particle-to-fluid mass ratio,the real and imaginary parts of leading-order asymptotic expression derived by the present model for the growth rate are shown to be identical to the earlier results derived by the classical Saffman model established for dusty gases.Beyond the known results,explicit leading-order asymptotic expressions for the effect of suspended particles on the growth rate are derived for several typical cases of basic interest.It is shown that the suspended particles can decrease or increase the growth rate of KH instability depending on the Stokes numbers of the particles and whether the particles are heavier or lighter than the clean fluid.Compared to the mass density of the clean fluid,our results based on leading-order asymptotic solutions show that heavier particles and lighter particles have opposite effects on the growth rate of KH instability,while the effect of neutrally buoyant particles on the growth rate of KH instability is negligible.展开更多
1.Challenges Thermoacoustic instability in combustors arises from the interaction between sound waves and unsteady heat release,commonly found in systems like gas turbines and aeroengines.This instability leads to und...1.Challenges Thermoacoustic instability in combustors arises from the interaction between sound waves and unsteady heat release,commonly found in systems like gas turbines and aeroengines.This instability leads to undesirable consequences such as structural damage and performance deterioration.The challenge lies in predicting and mitigating these instabilities due to the complex interplay of various physical phenomena like acoustic propagation,turbulent flow,and combustion chemistry,which are summarized in detail in Aimee S.Morgans and Dong Yang's published article.展开更多
We study the Rayleigh-Taylor instability(RTI)of electrostatic plane wave perturbations in compressible relativistic magnetoplasma fluids with thermal ions under gravity in three different cases of when(ⅰ)electrons ar...We study the Rayleigh-Taylor instability(RTI)of electrostatic plane wave perturbations in compressible relativistic magnetoplasma fluids with thermal ions under gravity in three different cases of when(ⅰ)electrons are in isothermal equilibrium,i.e.,classical or nondegenerate,(ⅱ)electrons are fully degenerate(with Te=0),and(ⅲ)electrons are partially degenerate or have finite temperature degeneracy(with Te≠0).While in the cases of(ⅰ)and(ⅲ),we focus on the regimes where the particle's thermal energy is more or less than the rest mass energy,i.e.,βe≡kBTe/mec2<1or>1,the case(ⅱ)considers from weakly to ultra-relativistic degenerate regimes.A general expression of the growth rate of instability is obtained and analyzed in the three different cases relevant to laboratory and astrophysical plasmas,which generalize and advance the previous theory on RTI.展开更多
To investigate the instability mechanisms of heterogeneous geological structures in goaf area roofs,three-point bending tests(TPBT)and numerical simulations are performed on composite coal-rock(CCR).Acoustic emission(...To investigate the instability mechanisms of heterogeneous geological structures in goaf area roofs,three-point bending tests(TPBT)and numerical simulations are performed on composite coal-rock(CCR).Acoustic emission(AE)monitoring is employed to analyze key parameters,establishing a multiparameter quantitative system for CCR fracture processes.The impact of lithological homogeneity on fracture evolution and energy migration is examined.Results show that CCR exhibits a three-stage mechanical response:weak contact,strong contact,and post-peak stages,each with distinct crack evolution patterns.A positive correlation is found between lithological homogeneity and tensile crack proportion.No significant correlation is observed between AE average frequency(AF)and AE counts across different lithological CCR;however,peak frequency(PF)displays clear lithology-dependent characteristics.The regulatory effect of the rock homogeneity coefficient(φ)on crack deriva tion mechanisms is quantfied,yielding mathematical relationships between fracture strength(f),crack propagation path angle(β),crack fractal dimension(D),andφ.The study highlights how different fracture modes alter energy migration pathways,confirming the coupling effect of grain distribution on mechanical response and crack propagation,and the influence of parameterφon critical energy release zones.These findings offer new insights into CCR failure mechanisms for mining safety.展开更多
The retrospective cohort study by Zuo et al investigates the interplay between microsatellite instability(MSI)status,nutritional indicators,and inflammatory profiles in colorectal cancer(CRC).Analyzing 56 patients,the...The retrospective cohort study by Zuo et al investigates the interplay between microsatellite instability(MSI)status,nutritional indicators,and inflammatory profiles in colorectal cancer(CRC).Analyzing 56 patients,the study reveals that MSI-high tumors are associated with significantly lower serum albumin,body mass index,and absolute lymphocyte counts,alongside elevated neutrophil-tolymphocyte ratios compared to microsatellite stable tumors.These findings highlight distinct immunological and nutritional profiles in MSI-high CRC,suggesting potential clinical utility in risk stratification and personalized treat-ment.While the study underscores the importance of MSI status in CRC mana-gement,its single-center design and limited sample size warrant validation through multicenter trials.This article contextualizes these findings within the broader landscape of CRC research,emphasizing the need for integrating bio-markerdriven strategies into clinical practice to optimize outcomes for patients with differing MSI statuses.展开更多
Objective:Lynch syndrome(LS)increases the risk of various cancers,including colorectal cancer,endometrial cancer and gastric cancer(GC).The incidence of LS among microsatellite instability-high(MSI-H)GC and their asso...Objective:Lynch syndrome(LS)increases the risk of various cancers,including colorectal cancer,endometrial cancer and gastric cancer(GC).The incidence of LS among microsatellite instability-high(MSI-H)GC and their association in South Korea remains underexplored.This study investigates LS-associated pathogenic germline variants in MSI-H GC patients using whole-exome sequencing(WES)on normal tissues.Methods:This retrospective study included patients who underwent gastrectomy for GC at Soonchunhyang University Bucheon and Cheonan Hospitals from January 2011 to October 2023.Among 1,537 patients screened for MSI status,127(8.3%)were identified as MSI-H.WES was performed on normal tissues from 123 patients.Pathogenic/likely pathogenic(P/LP)variants in mismatch repair(MMR)genes were identified using in silico models and protein loss assessments in corresponding tumor tissues.Results:Of the 127 MSI-H GC cases,characteristics aligned with typical MSI-H GC.The average age was70.02 years,with 98(77.2%)located in the lower body and 81(63.8%)of the intestinal type.All five MSI markers were positive in 46.5%of cases,whereas four markers were positive in 27.6%.Of the MSI-H GCs,10 LS candidates were identified.Three patients had known P/LP variants[MLH1(c.1758dup),MSH6(c.3261dup),MSH2(c.1241T>C)].Seven patients had variants of unknown significance(VUS)in MMR genes.Six(4.9%)patients were identified as having LS or possible LS,including one patient with the MLH1(c.1153C>T)variant previously classified as VUS but now considered LS-associated.Conclusions:This large-scale screening for LS in MSI-H GC patients using retrospective samples confirmed the lower incidence of LS than those of colorectal or endometrial cancer and GC patients in Western countries,emphasizing the need for clinical consideration in managing MSI-H GC patients.展开更多
Shallow-buried thick sand strata present considerable local instability risks during diaphragm wall trenching construction.However,this critical issue has not been extensively studied,despite its serious safety conseq...Shallow-buried thick sand strata present considerable local instability risks during diaphragm wall trenching construction.However,this critical issue has not been extensively studied,despite its serious safety consequences.This paper proposes an automatic identification model for shallow-buried thick sand strata,integrating three-dimensional limit equilibrium theory with a genetic algorithm to precisely identify the most potentially dangerous local instability mass and determine its minimum safety factor.The model establishes three undetermined parameters:failure angle,upper boundary,and thickness of the local instability mass.These parameters define the search space for the local instability mass.The effectiveness of this approach was confirmed through a diaphragm wall engineering case near the Rhine River in France,where the predicted instability location closely aligned with field observations.A systematic analysis of the model indicated that the difference in slurry-groundwater levels and the friction angle are the most significant factors affecting local instability in shallow-buried thick sand strata.The model indicated that the location of the most potentially dangerous instability mass changes depending on geological conditions,and larger instability masses do not always relate to lower safety factors.Additionally,exploratory experiments revealed that support pressure losses caused by slurry infiltration significantly influence local instability calculations in sand strata.This points out the importance of considering these support pressure losses in the stability evaluations of high permeable sand strata.The results improve the evaluation of safety and the optimization of design for diaphragm wall construction in shallow-buried thick sand strata.展开更多
This study investigates the instability characteristics of dynamic disasters resulting from disruption caused by extracting resources underground. Utilizing the split Hopkinson pressure bar (SHPB) system, the dynamic ...This study investigates the instability characteristics of dynamic disasters resulting from disruption caused by extracting resources underground. Utilizing the split Hopkinson pressure bar (SHPB) system, the dynamic response mechanism of coal energy evolution is examined, and the energy instability criterion is established. The validity of the instability criterion is explored from the standpoint of damage progression. The results demonstrate that the energy conversion mechanism undergoes a fundamental alternation under impact disturbance. Moreover, the energy release rate as well as the energy dissipation rate undergo comparable changes across distinct levels of impact disturbance. The distinction between the energy release rate and the energy dissipation rate (DRD) increases as coal mass deformation grows. Prior to coal facing instability and failure, the DRD experienced an inflection point followed by a sharp decrease. In conjunction with the discussion on the damage evolution, the physical and mechanical significance of DRD remains clear, which can essentially describe the whole impact loading process. The phenomenon that the inflection point appears and DRD subsequently suddenly decreases can be employed as the energy criterion prior to the failure of instability. Furthermore, this paper provides significant reference for the prediction of dynamic instability of coal under dynamic disturbance.展开更多
Columnar jointed rock mass(CJRM)combines and mosaic of slender rock columns with different height-to-width(H/W)ratios.Revealing the correlation of the mechanical behavior of individual rock columns with internal facto...Columnar jointed rock mass(CJRM)combines and mosaic of slender rock columns with different height-to-width(H/W)ratios.Revealing the correlation of the mechanical behavior of individual rock columns with internal factors(H/W ratio and material strength)and external factor(lateral pressure)is fundamental to understanding the deterioration of CJRM.We adopt a numerical scheme that combines a statistical meso-damage constitutive model with a finite element formulation based on finite deformation,which can simultaneously consider both material failure and structural instability of the rock columns.Compression tests of rock columns with different H/W ratios and material strengths under varying lateral pressures were conducted to analyze the macro-strength features and failure modes.The numerical results show that increasing the material strength can improve the macro-strength,while the effect of H/W ratio is the opposite.Both increases can promote the conversion of failure modes,and the evolution process is as follows:material failure-induced structural instability→synergy and competition between material failure and structural instability→structural instability-induced material failure.Notably,for the last failure mode,an increase in lateral pressure decreases the macro-strength of the rock column and heightens its instability risk.This finding provides new insights into the response of rocks with different H/W ratios under lateral pressure,extending beyond traditional material-based perspectives.According to the position of the failure mode demarcation line,the failure mode of the rock column can be regulated.展开更多
BACKGROUND Psychological comorbidities,such as anxiety and depression,in patients with chronic ankle instability(CAI)may impede ankle function improvement,although the precise nature of this association warrants furth...BACKGROUND Psychological comorbidities,such as anxiety and depression,in patients with chronic ankle instability(CAI)may impede ankle function improvement,although the precise nature of this association warrants further investigation.AIM To analyze the correlation of anxiety and depression with ankle function in patients with CAI and discussing the risk factors.METHODS This study included 116 patients with CAI,who were admitted to our hospital from July 2022 to July 2024.Anxiety and depression states of patients were assessed with the self-rating anxiety scale(SAS)and self-rating depression scale(SDS),respectively,and their ankle joint function was assessed with the anklehindfoot function score of the American Orthopedic Foot and Ankle Society.Further,the ankle function of patients with CAI with different anxiety and depression states was discussed.Furthermore,the Pearson correlation coefficient was used to analyze the correlation of anxiety and depression with ankle joint function in such patients.Univariate and multivariate analyses were conducted to investigate the factors affecting ankle joint function in patients with CAI.RESULTS Among the 116 patients with CAI,97,13,5,and 1 cases demonstrated none,mild,moderate,and severe anxiety,whereas 95,15,6,and 0 cases showed none,mild,moderate,and severe depression,respectively.The average ankle joint function score was 74.82±6.93 points.The ankle joint function in patients with CAI presented a significant downward tendency as the degree of anxiety and depression increased.Correlation analysis revealed that both the SAS and SDS scores of patients with CAI were significantly negatively correlated with the ankle joint function score.Univariate and multivariate analyses indicated that the risk factors affecting patients’ankle joint function included early functional rehabilitation,visual analog scale,and SDS.CONCLUSION A substantial number of patients with CAI suffer from anxiety and depression,and these negative emotions,to a certain extent,harm the smooth rehabilitation of ankle joint function.展开更多
BACKGROUND Colorectal cancer stands among the most prevalent digestive system malignancies.The microsatellite instability(MSI)profile plays a crucial role in determining patient outcomes and therapy responsiveness.Tra...BACKGROUND Colorectal cancer stands among the most prevalent digestive system malignancies.The microsatellite instability(MSI)profile plays a crucial role in determining patient outcomes and therapy responsiveness.Traditional MSI evaluation methods require invasive tissue sampling,are lengthy,and can be compromised by intratumoral heterogeneity.AIM To establish a non-invasive technique utilizing dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)radiomics and machine learning algorithms to determine MSI status in patients with intermediate-stage rectal cancer.METHODS This retrospective analysis examined 120 individuals diagnosed with stage II/III rectal cancer[30 MSI-high(MSI-H)and 90 microsatellite stability(MSS)/MSI-low(MSI-L)cases].We extracted comprehensive radiomics signatures from DCE-MRI scans,encompassing textural parameters that reflect tumor heterogeneity,shapebased metrics,and histogram-derived statistical values.Least absolute shrinkage and selection operator regression facilitated feature selection,while predictive frameworks were developed using various classification algorithms(logistic regression,support vector machine,and random forest).Performance assessment utilized separate training and validation cohorts.RESULTS Our investigation uncovered distinctive imaging characteristics between MSI-H and MSS/MSI-L neoplasms.MSIH tumors exhibited significantly elevated entropy values(7.84±0.92 vs 6.39±0.83,P=0.004),enhanced surface-tovolume proportions(0.72±0.14 vs 0.58±0.11,P=0.008),and heightened signal intensity variation(3642±782 vs 2815±645,P=0.007).The random forest model demonstrated superior classification capability with area under the curves(AUCs)of 0.891 and 0.896 across training and validation datasets,respectively.An integrated approach combining radiomics with clinical parameters further enhanced performance metrics(AUC 0.923 and 0.914),achieving 88.5%sensitivity alongside 87.2%specificity.CONCLUSION DCE-MRI radiomics features interpreted through machine learning frameworks offer an effective strategy for MSI status assessment in intermediate-stage rectal cancer.展开更多
BACKGROUND Mismatch repair deficient/microsatellite instability-high(MMR-D/MSI-H)colorectal cancers(CRCs)possess a distinctive genomic profile that results in a spectrum of phenotypic attributes setting them apart fro...BACKGROUND Mismatch repair deficient/microsatellite instability-high(MMR-D/MSI-H)colorectal cancers(CRCs)possess a distinctive genomic profile that results in a spectrum of phenotypic attributes setting them apart from their mismatch repair proficient(MMR-P)or microsatellite stable(MSS)counterparts.CRCs have several prognostic factors,including stage,tumor differentiation,location,lymphovascular and perineural invasion,tumor budding,tumor infiltrating lymphocytes,lymph node yield(LNY),and lymph node ratio(LNR).AIM To determine the unique phenotypic characteristics of MMR-D/MSI-H CRCs and leverage the conventional wisdom of LNY and LNR with the distinctive characteristics of MMR-D/MSI-H CRCs.METHODS This retrospective analysis involved 223 stage I-III CRC patients who underwent surgical resection without neoadjuvant treatment.Clinical and histological features were obtained from patient records and by re-examining the hematoxylin and eosin-stained slides.MMR/MSI status was evaluated for all patients using either MMR immunohistochemistry or MSI testing.RESULTS Of the 223 patients in our study,87(39.01%)were MMR-D/MSI-H CRCs while 136(60.99%)were MMR-P/MSS CRCs.The MMR-D/MSI-H CRCs exhibited significant statistical differences compared to the MMR-P/MSS CRCs in several factors,including location,stage,tumor budding,lymphovascular and perineural invasion,lymphocytic response,LNY,LNR,and size of uninvolved lymph nodes.LNY and LNR were significantly higher in MMR-D/MSI-H group compared with the MMR-P/MSS group(P=0.003 and P<0.001,respectively).Also,the interquartile range of the largest uninvolved lymph node was 1 cm(0.8 cm-1.2 cm)in MMR-D/MSI-H CRCs compared to 0.7 cm(0.6 cm-0.97 cm)in MMRP/MSS CRCs.The overall survival for the MMR-P/MSS CRC group was 71%at five years,and the MMR-D/MSIH CRC group was 92%at five years(P<0.001).CONCLUSION MMR-D/MSI-H CRCs possess a unique genomic profile that leads to distinct phenotypic characteristics,including an enhanced immune response.This distinctive profile underscores the substantial prognostic and predictive value of MMR-D/MSI-H status in CRC.展开更多
A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary ...A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary patterns to asynchronous and synchronous oscillatory patterns are obtained.A novel method based on decomposing coupled systems into two associated subsystems has been proposed to elucidate the mechanism of formation of oscillating patterns.Linear stability analysis of the associated subsystems reveals that the Turing pattern in one layer induces the other layer locally,undergoes a supercritical Hopf bifurcation and gives rise to localized oscillations.It is found that the sizes and positions of oscillations are determined by the spatial distribution of the Turing patterns.When the size is large,localized traveling waves such as spirals and targets emerge.These results may be useful for deeper understanding of pattern formation in complex systems,particularly multilayered systems.展开更多
基金support of the National Natural Science Foundation of China(No.52322603)the Science Center for Gas Turbine Project of China(Nos.P2022-B-II-004-001 and P2023-B-II-001-001)+1 种基金the Fundamental Research Funds for the Central Universities,Chinathe Beijing Nova Program of China(Nos.20220484074 and 20230484479).
文摘The utilization of Inlet Guide Vane (IGV) plays a key factor in affecting the instability evolution. Existing literature mainly focuses on the effect of IGV on instability inception that occurs in the rotor region. However, with the emergence of compressor instability starting from the stator region, the mechanism of various instability inceptions that occurs in different blade rows due to the change of IGV angles should be further examined. In this study, experiments were focused on three types of instability inceptions observed previously in a 1.5-stage axial flow compressor. To analyze the conversion of stall evolutions, the compressor rotating speed was set to 17 160 r/min, at which both the blade loading in the stator hub region and rotor tip region were close to the critical value before final compressor stall. Meanwhile, the dynamic test points with high-response were placed to monitor the pressures both at the stator trailing edges and rotor tips. The results indicate that the variation of reaction determines the region where initial instability occurs. Indeed, negative pre-rotation of the inlet guide vane leads to high-reaction, initiating stall disturbance from the rotor region. Positive pre-rotation results in low-reaction, initiating stall disturbance from the stator region. Furthermore, the type of instability evolution is affected by the radial loading distribution under different IGV angles. Specifically, a spike-type inception occurs at the rotor blade tip with a large angle of attack at the rotor inlet (−2°, −4° and −6°). Meanwhile, the critical total pressure ratio at the rotor tip is 1.40 near stall. As the angle of attack decreases, the stator blade loading reaches its critical boundary, with a value of approximately 1.35. At this moment, if the rotor tip maintains high blade loading similar to the stator hub, the partial surge occurs (0° and +2°);otherwise, the hub instability occurs (+4° and +6°).
基金was supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1611200 and 2018YFA0307000)the National Natural Science Foundation of China(Grant Nos.12274154 and 12404182)。
文摘In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-binding Hamiltonian including onsite Coulomb repulsion U,V,and spin-orbital couplingλ.The program is applied to Ba_(2)MgReO_(6)to fgure out the mechanism of structural instability and magnetic ordering.A comprehensive quadrupole phase diagram versus U and V withλ=0.28 eV is calculated.Our results demonstrate that the easy-plane anisotropy and the intersite Coulomb repulsion V must be considered to remove the orbital frustration.The increase of V to>20 meV would arrange quadrupole Q_(x^(2)-y^(2))antiparallelly,accompanied by small parallel Q_(3z)^(2)-r^(2),and stabilize Ba_(2)MgReO_(6)into the body-centered tetragonal structure.Such antiparallel Q_(x^(2)-y^(2))provides a new mechanism for the Dzyaloshinskii-Moriya interaction and gives rise to the canted antiferromagnetic(CAF)state along the[110]axis.Moreover,sizable octupoles such as O_(21)^(31),O_(21)^(33),O_(21)^(34)and O_(21)^(36)are discovered for the frst time in the CAF state.Our study not only provides a comprehensive understanding of the experimental results in Ba_(2)MgReO_(6),but also serves as a general and useful tool for the study of multipole physics in 5d compounds.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.12074399,12204500,and 12004403)the Key Projects of the Intergovernmental International Scientifi and Technological Innovation Cooperation(Grant No.2021YFE0116700)+1 种基金the Shanghai Natural Science Foundation(Grant No.20ZR1464400)the Shanghai Sailing Program(Grant No.22YF1455300)。
文摘The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the plasma acceleration phase,shorter wavelengths lead to more efficien coupling between the laser and the kinetic energy of the implosion fluid Under the condition that the laser energy coupled to the implosion flui is constant,the ARTI growth rate decreases as the laser wavelength moves toward the extreme ultraviolet band,reaching its minimum value near λ=65 nm,and when the laser wavelength continuously moves toward the X-ray band,the ARTI growth rate increases rapidly.It is found that the results deviate from the theoretical ARTI growth rate.As the laser intensity benchmark increases,the position of the minimum ARTI growth rate shifts toward shorter wavelengths.As the initial sinusoidal perturbation wavenumber decreases,the position of the minimum ARTI growth rate shifts toward longer wavelengths.We believe that the conclusions drawn from the present simulations and analysis will help provide a better understanding of the ICF process and improve the theory of ARTI growth.
基金funded by the National Key R&D Program of China(Grant No.2023YFA1608400)the National Natural Science Foundation of China(Grant No.12302281).
文摘Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,insufficient doping of the ablator material can result in highenergy X-ray preheat,which may trigger the development of a classical-like Rayleigh-Taylor instability(RTI)at the fuel-ablator interface.In implosion experiments at the Shenguang 100 kJ-level laser facility,the primary source of perturbation is the roughness of the inner DT ice interface.In this study,we propose an analytical model to describe the feed-out process of the initial roughness of the inner DT ice interface.The perturbation amplitude derived from this model serves as the initial seed for the late-time RTI during the acceleration phase.Our findings confirm the presence of classical-like RTI at the fuel-ablator interface.Numerical simulations conducted using a radiation hydrodynamic code validate the proposed analytical model and demonstrate the existence of a peak mode number in both the feed-out process and the classical-like RTI.It provides an alternative bridge between the current target fabrication limitations and the unexpected implosion performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.11972027,12472093,and 11772272)the New Interdisciplinary Cultivation Fund of Southwest Jiaotong University(Grant No.2682022JX001)+1 种基金the Frontier Science and Technology Cultivation Project of Southwest Jiaotong University(Grant No.2682022KJ048)the Laboratory of Flexible Electronics Technology at Tsinghua University.
文摘Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming.Although there exist diverse bi-stable structures capable of snap-through instability,it is still difficult for a structure with high slenderness to undergo the axial snap-through instability with a large stroke.Here,an elastic structure with high slenderness is simply constructed by a finite number of identical,conventional bi-stable units with relatively low slenderness in series connection.For realizing the axial snap-through instability with a large stroke,common scissors mechanisms are further introduced as rigid constraints to guarantee the synchronous snap-through instability of these bi-stable units.The global feature of the large-stroke snap-through instability realized here is robust and even insusceptible to the local out-of-synchronization of individual units.The present design provides a simple and feasible way to achieve the large-stroke snap-through instability of slender structures,which is expected to be particularly useful for state switching and energy transforming in narrow spaces.
基金supports of the National Natural Science Foundation of China(Nos.52076129,92360308,52376027)the Shanghai Municipal Education Commission of China(No.2023-02-4)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe United Innovation Center(UIC)of Aerothermal Technologies for Turbomachinery of China.
文摘Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs.
基金Project supported by the National Natural Science Foundation of China(Nos.12471367 and12361076)the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region(Nos.NJZY19186,NJZY22036,and NJZY23003)。
文摘We are intrigued by the issues of shock instability,with a particular emphasis on numerical schemes that address the carbuncle phenomenon by reducing dissipation rather than increasing it.For a specific class of planar flow fields where the transverse direction exhibits vanishing but non-zero velocity components,such as a disturbed onedimensional(1D)steady shock wave,we conduct a formal asymptotic analysis for the Euler system and associated numerical methods.This analysis aims to illustrate the discrepancies among various low-dissipative numerical algorithms.Furthermore,a numerical stability analysis of steady shock is undertaken to identify the key factors underlying shock-stable algorithms.To verify the stability mechanism,a consistent,low-dissipation,and shock-stable HLLC-type Riemann solver is presented.
文摘A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to study the effect of suspended particles on the growth rate of KH instability.For dusty gases with negligible volume fraction of heavy particles and small particle-to-fluid mass ratio,the real and imaginary parts of leading-order asymptotic expression derived by the present model for the growth rate are shown to be identical to the earlier results derived by the classical Saffman model established for dusty gases.Beyond the known results,explicit leading-order asymptotic expressions for the effect of suspended particles on the growth rate are derived for several typical cases of basic interest.It is shown that the suspended particles can decrease or increase the growth rate of KH instability depending on the Stokes numbers of the particles and whether the particles are heavier or lighter than the clean fluid.Compared to the mass density of the clean fluid,our results based on leading-order asymptotic solutions show that heavier particles and lighter particles have opposite effects on the growth rate of KH instability,while the effect of neutrally buoyant particles on the growth rate of KH instability is negligible.
文摘1.Challenges Thermoacoustic instability in combustors arises from the interaction between sound waves and unsteady heat release,commonly found in systems like gas turbines and aeroengines.This instability leads to undesirable consequences such as structural damage and performance deterioration.The challenge lies in predicting and mitigating these instabilities due to the complex interplay of various physical phenomena like acoustic propagation,turbulent flow,and combustion chemistry,which are summarized in detail in Aimee S.Morgans and Dong Yang's published article.
基金support from the University Grants Commission(UGC),Government of India,for a Senior Research Fellowship(SRF)with Ref.No.1161/(CSIR-UGC NET DEC.2018)and 16-6(DEC.2018)/2019(NET/CSIR)。
文摘We study the Rayleigh-Taylor instability(RTI)of electrostatic plane wave perturbations in compressible relativistic magnetoplasma fluids with thermal ions under gravity in three different cases of when(ⅰ)electrons are in isothermal equilibrium,i.e.,classical or nondegenerate,(ⅱ)electrons are fully degenerate(with Te=0),and(ⅲ)electrons are partially degenerate or have finite temperature degeneracy(with Te≠0).While in the cases of(ⅰ)and(ⅲ),we focus on the regimes where the particle's thermal energy is more or less than the rest mass energy,i.e.,βe≡kBTe/mec2<1or>1,the case(ⅱ)considers from weakly to ultra-relativistic degenerate regimes.A general expression of the growth rate of instability is obtained and analyzed in the three different cases relevant to laboratory and astrophysical plasmas,which generalize and advance the previous theory on RTI.
基金support from the National Key Research and Development Plan Project(No.2022YFC3004700)the National Natural Science Foundation of China(No.52374241)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_2924)Graduate Innovation Program of China University of Mining and Technology(No.2024WLKXJ151).
文摘To investigate the instability mechanisms of heterogeneous geological structures in goaf area roofs,three-point bending tests(TPBT)and numerical simulations are performed on composite coal-rock(CCR).Acoustic emission(AE)monitoring is employed to analyze key parameters,establishing a multiparameter quantitative system for CCR fracture processes.The impact of lithological homogeneity on fracture evolution and energy migration is examined.Results show that CCR exhibits a three-stage mechanical response:weak contact,strong contact,and post-peak stages,each with distinct crack evolution patterns.A positive correlation is found between lithological homogeneity and tensile crack proportion.No significant correlation is observed between AE average frequency(AF)and AE counts across different lithological CCR;however,peak frequency(PF)displays clear lithology-dependent characteristics.The regulatory effect of the rock homogeneity coefficient(φ)on crack deriva tion mechanisms is quantfied,yielding mathematical relationships between fracture strength(f),crack propagation path angle(β),crack fractal dimension(D),andφ.The study highlights how different fracture modes alter energy migration pathways,confirming the coupling effect of grain distribution on mechanical response and crack propagation,and the influence of parameterφon critical energy release zones.These findings offer new insights into CCR failure mechanisms for mining safety.
文摘The retrospective cohort study by Zuo et al investigates the interplay between microsatellite instability(MSI)status,nutritional indicators,and inflammatory profiles in colorectal cancer(CRC).Analyzing 56 patients,the study reveals that MSI-high tumors are associated with significantly lower serum albumin,body mass index,and absolute lymphocyte counts,alongside elevated neutrophil-tolymphocyte ratios compared to microsatellite stable tumors.These findings highlight distinct immunological and nutritional profiles in MSI-high CRC,suggesting potential clinical utility in risk stratification and personalized treat-ment.While the study underscores the importance of MSI status in CRC mana-gement,its single-center design and limited sample size warrant validation through multicenter trials.This article contextualizes these findings within the broader landscape of CRC research,emphasizing the need for integrating bio-markerdriven strategies into clinical practice to optimize outcomes for patients with differing MSI statuses.
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2022R1A2C2092005)the Soonchunhyang University Research Fund。
文摘Objective:Lynch syndrome(LS)increases the risk of various cancers,including colorectal cancer,endometrial cancer and gastric cancer(GC).The incidence of LS among microsatellite instability-high(MSI-H)GC and their association in South Korea remains underexplored.This study investigates LS-associated pathogenic germline variants in MSI-H GC patients using whole-exome sequencing(WES)on normal tissues.Methods:This retrospective study included patients who underwent gastrectomy for GC at Soonchunhyang University Bucheon and Cheonan Hospitals from January 2011 to October 2023.Among 1,537 patients screened for MSI status,127(8.3%)were identified as MSI-H.WES was performed on normal tissues from 123 patients.Pathogenic/likely pathogenic(P/LP)variants in mismatch repair(MMR)genes were identified using in silico models and protein loss assessments in corresponding tumor tissues.Results:Of the 127 MSI-H GC cases,characteristics aligned with typical MSI-H GC.The average age was70.02 years,with 98(77.2%)located in the lower body and 81(63.8%)of the intestinal type.All five MSI markers were positive in 46.5%of cases,whereas four markers were positive in 27.6%.Of the MSI-H GCs,10 LS candidates were identified.Three patients had known P/LP variants[MLH1(c.1758dup),MSH6(c.3261dup),MSH2(c.1241T>C)].Seven patients had variants of unknown significance(VUS)in MMR genes.Six(4.9%)patients were identified as having LS or possible LS,including one patient with the MLH1(c.1153C>T)variant previously classified as VUS but now considered LS-associated.Conclusions:This large-scale screening for LS in MSI-H GC patients using retrospective samples confirmed the lower incidence of LS than those of colorectal or endometrial cancer and GC patients in Western countries,emphasizing the need for clinical consideration in managing MSI-H GC patients.
基金supported by the Fundamental Research Funds for the Central Universities(No.02302350113).
文摘Shallow-buried thick sand strata present considerable local instability risks during diaphragm wall trenching construction.However,this critical issue has not been extensively studied,despite its serious safety consequences.This paper proposes an automatic identification model for shallow-buried thick sand strata,integrating three-dimensional limit equilibrium theory with a genetic algorithm to precisely identify the most potentially dangerous local instability mass and determine its minimum safety factor.The model establishes three undetermined parameters:failure angle,upper boundary,and thickness of the local instability mass.These parameters define the search space for the local instability mass.The effectiveness of this approach was confirmed through a diaphragm wall engineering case near the Rhine River in France,where the predicted instability location closely aligned with field observations.A systematic analysis of the model indicated that the difference in slurry-groundwater levels and the friction angle are the most significant factors affecting local instability in shallow-buried thick sand strata.The model indicated that the location of the most potentially dangerous instability mass changes depending on geological conditions,and larger instability masses do not always relate to lower safety factors.Additionally,exploratory experiments revealed that support pressure losses caused by slurry infiltration significantly influence local instability calculations in sand strata.This points out the importance of considering these support pressure losses in the stability evaluations of high permeable sand strata.The results improve the evaluation of safety and the optimization of design for diaphragm wall construction in shallow-buried thick sand strata.
基金Projects(51934007,12072363,52004268) supported by the National Natural Science Foundation of ChinaProject(22KJD440002) supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,China。
文摘This study investigates the instability characteristics of dynamic disasters resulting from disruption caused by extracting resources underground. Utilizing the split Hopkinson pressure bar (SHPB) system, the dynamic response mechanism of coal energy evolution is examined, and the energy instability criterion is established. The validity of the instability criterion is explored from the standpoint of damage progression. The results demonstrate that the energy conversion mechanism undergoes a fundamental alternation under impact disturbance. Moreover, the energy release rate as well as the energy dissipation rate undergo comparable changes across distinct levels of impact disturbance. The distinction between the energy release rate and the energy dissipation rate (DRD) increases as coal mass deformation grows. Prior to coal facing instability and failure, the DRD experienced an inflection point followed by a sharp decrease. In conjunction with the discussion on the damage evolution, the physical and mechanical significance of DRD remains clear, which can essentially describe the whole impact loading process. The phenomenon that the inflection point appears and DRD subsequently suddenly decreases can be employed as the energy criterion prior to the failure of instability. Furthermore, this paper provides significant reference for the prediction of dynamic instability of coal under dynamic disturbance.
基金supported in part by the National Natural Science Foundation of China(4227233052079019)+1 种基金the Liaoning Province Science and Technology Plan Joint Program(Applied Basic Research Project)(2023JH2/101700340)the Fundamental Research Funds for the Central Universities(DUT24ZD135).
文摘Columnar jointed rock mass(CJRM)combines and mosaic of slender rock columns with different height-to-width(H/W)ratios.Revealing the correlation of the mechanical behavior of individual rock columns with internal factors(H/W ratio and material strength)and external factor(lateral pressure)is fundamental to understanding the deterioration of CJRM.We adopt a numerical scheme that combines a statistical meso-damage constitutive model with a finite element formulation based on finite deformation,which can simultaneously consider both material failure and structural instability of the rock columns.Compression tests of rock columns with different H/W ratios and material strengths under varying lateral pressures were conducted to analyze the macro-strength features and failure modes.The numerical results show that increasing the material strength can improve the macro-strength,while the effect of H/W ratio is the opposite.Both increases can promote the conversion of failure modes,and the evolution process is as follows:material failure-induced structural instability→synergy and competition between material failure and structural instability→structural instability-induced material failure.Notably,for the last failure mode,an increase in lateral pressure decreases the macro-strength of the rock column and heightens its instability risk.This finding provides new insights into the response of rocks with different H/W ratios under lateral pressure,extending beyond traditional material-based perspectives.According to the position of the failure mode demarcation line,the failure mode of the rock column can be regulated.
文摘BACKGROUND Psychological comorbidities,such as anxiety and depression,in patients with chronic ankle instability(CAI)may impede ankle function improvement,although the precise nature of this association warrants further investigation.AIM To analyze the correlation of anxiety and depression with ankle function in patients with CAI and discussing the risk factors.METHODS This study included 116 patients with CAI,who were admitted to our hospital from July 2022 to July 2024.Anxiety and depression states of patients were assessed with the self-rating anxiety scale(SAS)and self-rating depression scale(SDS),respectively,and their ankle joint function was assessed with the anklehindfoot function score of the American Orthopedic Foot and Ankle Society.Further,the ankle function of patients with CAI with different anxiety and depression states was discussed.Furthermore,the Pearson correlation coefficient was used to analyze the correlation of anxiety and depression with ankle joint function in such patients.Univariate and multivariate analyses were conducted to investigate the factors affecting ankle joint function in patients with CAI.RESULTS Among the 116 patients with CAI,97,13,5,and 1 cases demonstrated none,mild,moderate,and severe anxiety,whereas 95,15,6,and 0 cases showed none,mild,moderate,and severe depression,respectively.The average ankle joint function score was 74.82±6.93 points.The ankle joint function in patients with CAI presented a significant downward tendency as the degree of anxiety and depression increased.Correlation analysis revealed that both the SAS and SDS scores of patients with CAI were significantly negatively correlated with the ankle joint function score.Univariate and multivariate analyses indicated that the risk factors affecting patients’ankle joint function included early functional rehabilitation,visual analog scale,and SDS.CONCLUSION A substantial number of patients with CAI suffer from anxiety and depression,and these negative emotions,to a certain extent,harm the smooth rehabilitation of ankle joint function.
基金Supported by the Natural Science Foundation of Fujian Province,China,No.2022J011460。
文摘BACKGROUND Colorectal cancer stands among the most prevalent digestive system malignancies.The microsatellite instability(MSI)profile plays a crucial role in determining patient outcomes and therapy responsiveness.Traditional MSI evaluation methods require invasive tissue sampling,are lengthy,and can be compromised by intratumoral heterogeneity.AIM To establish a non-invasive technique utilizing dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)radiomics and machine learning algorithms to determine MSI status in patients with intermediate-stage rectal cancer.METHODS This retrospective analysis examined 120 individuals diagnosed with stage II/III rectal cancer[30 MSI-high(MSI-H)and 90 microsatellite stability(MSS)/MSI-low(MSI-L)cases].We extracted comprehensive radiomics signatures from DCE-MRI scans,encompassing textural parameters that reflect tumor heterogeneity,shapebased metrics,and histogram-derived statistical values.Least absolute shrinkage and selection operator regression facilitated feature selection,while predictive frameworks were developed using various classification algorithms(logistic regression,support vector machine,and random forest).Performance assessment utilized separate training and validation cohorts.RESULTS Our investigation uncovered distinctive imaging characteristics between MSI-H and MSS/MSI-L neoplasms.MSIH tumors exhibited significantly elevated entropy values(7.84±0.92 vs 6.39±0.83,P=0.004),enhanced surface-tovolume proportions(0.72±0.14 vs 0.58±0.11,P=0.008),and heightened signal intensity variation(3642±782 vs 2815±645,P=0.007).The random forest model demonstrated superior classification capability with area under the curves(AUCs)of 0.891 and 0.896 across training and validation datasets,respectively.An integrated approach combining radiomics with clinical parameters further enhanced performance metrics(AUC 0.923 and 0.914),achieving 88.5%sensitivity alongside 87.2%specificity.CONCLUSION DCE-MRI radiomics features interpreted through machine learning frameworks offer an effective strategy for MSI status assessment in intermediate-stage rectal cancer.
文摘BACKGROUND Mismatch repair deficient/microsatellite instability-high(MMR-D/MSI-H)colorectal cancers(CRCs)possess a distinctive genomic profile that results in a spectrum of phenotypic attributes setting them apart from their mismatch repair proficient(MMR-P)or microsatellite stable(MSS)counterparts.CRCs have several prognostic factors,including stage,tumor differentiation,location,lymphovascular and perineural invasion,tumor budding,tumor infiltrating lymphocytes,lymph node yield(LNY),and lymph node ratio(LNR).AIM To determine the unique phenotypic characteristics of MMR-D/MSI-H CRCs and leverage the conventional wisdom of LNY and LNR with the distinctive characteristics of MMR-D/MSI-H CRCs.METHODS This retrospective analysis involved 223 stage I-III CRC patients who underwent surgical resection without neoadjuvant treatment.Clinical and histological features were obtained from patient records and by re-examining the hematoxylin and eosin-stained slides.MMR/MSI status was evaluated for all patients using either MMR immunohistochemistry or MSI testing.RESULTS Of the 223 patients in our study,87(39.01%)were MMR-D/MSI-H CRCs while 136(60.99%)were MMR-P/MSS CRCs.The MMR-D/MSI-H CRCs exhibited significant statistical differences compared to the MMR-P/MSS CRCs in several factors,including location,stage,tumor budding,lymphovascular and perineural invasion,lymphocytic response,LNY,LNR,and size of uninvolved lymph nodes.LNY and LNR were significantly higher in MMR-D/MSI-H group compared with the MMR-P/MSS group(P=0.003 and P<0.001,respectively).Also,the interquartile range of the largest uninvolved lymph node was 1 cm(0.8 cm-1.2 cm)in MMR-D/MSI-H CRCs compared to 0.7 cm(0.6 cm-0.97 cm)in MMRP/MSS CRCs.The overall survival for the MMR-P/MSS CRC group was 71%at five years,and the MMR-D/MSIH CRC group was 92%at five years(P<0.001).CONCLUSION MMR-D/MSI-H CRCs possess a unique genomic profile that leads to distinct phenotypic characteristics,including an enhanced immune response.This distinctive profile underscores the substantial prognostic and predictive value of MMR-D/MSI-H status in CRC.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275065,12275064,12475203)the Natural Science Foundation of Hebei Province(Grant Nos.A2021201010 and A2024201020)+3 种基金Interdisciplinary Research Program of Natural Science of Hebei University(Grant No.DXK202108)Hebei Provincial Central Government Guiding Local Science and Technology Development Funds(Grant No.236Z1501G)Scientific Research and Innovation Team Foundation of Hebei University(Grant No.IT2023B03)the Excellent Youth Research Innovation Team of Hebei University(Grant No.QNTD202402)。
文摘A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary patterns to asynchronous and synchronous oscillatory patterns are obtained.A novel method based on decomposing coupled systems into two associated subsystems has been proposed to elucidate the mechanism of formation of oscillating patterns.Linear stability analysis of the associated subsystems reveals that the Turing pattern in one layer induces the other layer locally,undergoes a supercritical Hopf bifurcation and gives rise to localized oscillations.It is found that the sizes and positions of oscillations are determined by the spatial distribution of the Turing patterns.When the size is large,localized traveling waves such as spirals and targets emerge.These results may be useful for deeper understanding of pattern formation in complex systems,particularly multilayered systems.
