Preoperative prediction of perineural invasion of rectal cancer based on a magnetic resonance imaging radiomics model:A dual-center study

BACKGROUND Perineural invasion(PNI)has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer(RC).Preoperative prediction of PNI status is helpful for individualized treatment of RC.Recently,several radiomics studies have been used to predict the PNI status in RC,demonstrating a good predictive effect,but the results lacked generalizability.The preoperative prediction of PNI status is still challenging and needs further study.AIM To establish and validate an optimal radiomics model for predicting PNI status preoperatively in RC patients.METHODS This retrospective study enrolled 244 postoperative patients with pathologically confirmed RC from two independent centers.The patients underwent preoperative high-resolution magnetic resonance imaging(MRI)between May 2019 and August 2022.Quantitative radiomics features were extracted and selected from oblique axial T2-weighted imaging(T2WI)and contrast-enhanced T1WI(T1CE)sequences.The radiomics signatures were constructed using logistic regression analysis and the predictive potential of various sequences was compared(T2WI,T1CE and T2WI+T1CE fusion sequences).A clinical-radiomics(CR)model was established by combining the radiomics features and clinical risk factors.The internal and external validation groups were used to validate the proposed models.The area under the receiver operating characteristic curve(AUC),DeLong test,net reclassification improvement(NRI),integrated discrimination improvement(IDI),calibration curve,and decision curve analysis(DCA)were used to evaluate the model performance.RESULTS Among the radiomics models,the T2WI+T1CE fusion sequences model showed the best predictive performance,in the training and internal validation groups,the AUCs of the fusion sequence model were 0.839[95%confidence interval(CI):0.757-0.921]and 0.787(95%CI:0.650-0.923),which were higher than those of the T2WI and T1CE sequence models.The CR model constructed by combining clinical risk factors had the best predictive performance.In the training and internal and external validation groups,the AUCs of the CR model were 0.889(95%CI:0.824-0.954),0.889(95%CI:0.803-0.976)and 0.894(95%CI:0.814-0.974).Delong test,NRI,and IDI showed that the CR model had significant differences from other models(P<0.05).Calibration curves demonstrated good agreement,and DCA revealed significant benefits of the CR model.CONCLUSION The CR model based on preoperative MRI radiomics features and clinical risk factors can preoperatively predict the PNI status of RC noninvasively,which facilitates individualized treatment of RC patients.

Recent Advances in Fibrous Materials for Hydroelectricity Generation

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.

Atomic-scale insights into microscopic mechanisms of grain boundary segregation in Al−Cu alloys

This study aims to clarify the mechanisms for the grain boundary(GB)segregation through investigating the absorption of excess solute atoms at GBs in Al−Cu alloys by using the hybrid molecular dynamics/Monte Carlo simulations.Two segregation mechanisms,substitutional and interstitial mechanisms,are observed.The intergranular defects,including dislocations,steps and vacancies,and the intervals in structural units are conductive to the prevalence of interstitial mechanism.And substitutional mechanism is favored by the highly ordered twin GBs.Furthermore,the two mechanisms affect the GB structure differently.It is quantified that interstitial mechanism is less destructive to GB structure than substitutional one,and often leads to a segregation level being up to about 6 times higher than the latter.These findings contribute to atomic scale insights into the microscopic mechanisms about how solute atoms are absorbed by GB structures,and clarify the correlation among intergranular structures,segregation mechanisms and kinetics.

Study on the antiulcer effects of Veronicastrum axillare on gastric ulcer in rats induced by ethanol based on tumor necrosis factor-α(TNF-α)and endothelin-1(ET-1)

Objective:To assess whether Veronicastrum axillare(V.axillare)can ameliorate ethanol-induced gastric mucosal lesions in rats,reduce the production of pro-inflammatory cytokines,suppress apoptosis and improve local microcirculation disturbances.Methods:Totally 48 male Sprague-Dawley rats were randomly divided into six groups,eight rats in each group.Rats in the normal group and the model group were administered with 0.9%normal saline respectively.Rats in the positive group and ranitidine group were administered with 0.18%ranitidine suspension by intragastric administration respectively.Those in the high dose V.axillare group,the medium dose V.axillare group and the low dose V.axillare group were administrated with V.axillare at the daily dose of 2.8 g/kg,1.4 g/kg and 0.7 g/kg by intragastric administration.Gastric mucosal lesions were produced by intragastric administration of absolute ethanol.Water extract of V.axillare was successively injected for 14 d and last day was injected 1 h before ethanol administration.Gastric mucosal ulcer index and ulcer inhibitory rate were counted by improved Guth methods.The tissue sections were made for pathological histology analysis.Also,we measured the concentrations of tumor necrosis factor-α(TNF-α)and endothelin-1(ET-1)in gastric mucosal,as an index of the pro-inflammatory cytokines,apoptosis and local microcirculation.Besides,the mRNA contents of TNF-αand ET-1 were measured to verify effects on gene expression by real-time fluorescent quantitative PCR.Results:Water extract of V.axillare significantly ameliorated the gastric mucosal lesions induced by ethanol administration(P【0.01).Pro-inflammatory cytokines,TNF-a and ET-1 were increased after ethanol administration and significantly reduced by water extract of V.axillare.The expressions of TNF-αand ET-1 mRNA were also be inhibited by water extract of V.axillare.Conclusion:Current evidences show water extract of V.axillare is effective for defending against ethanol-induced gastric mucosal lesions,significantly inhibiting the production of proinflammatory cytokines and the expressions of TNF-αand ET-1 mRNA,which may be useful for inhibiting apoptosis and improving local microcirculation.

Thoracic epidural angiolipoma: A case report and review of the literature

Angiolipoma of the spine is a benign neoplasm consisting of both mature fatty tissue and abnormal vascular elements, and usually presents with a slow progressive clinical course. Our patient presented with bilateral lower extremity weakness and chest-back numbness. Physical examination revealed adipose elements superficial hypesthesia below the T5 level and analgesia below the T6 level. Magnetic resonance imaging (MRI) scan showed an avidly and heterogeneously enhancing mass which was located in the posterior epidural space. Compression of the thoracic cord by the fusiform mass was seen between T3-T4. During the operation, a flesh pink vascular mass (4.7 cm × 1.0 cm × 1.0 cm) with obscure margin and strong but pliable texture was found in the posterior epidural space extending from T3 to T4. There was no infiltration of the dura or the adjacent bony spine. Histopathological study of the surgical specimen showed a typical angiolipoma. We review the previously documented cases of spinal extradural angiolipomas performed with MRI.

Study on the Reasons and Countermeasures for Loss of Listed Companies in Manufacturing Industry

In combination with the data of loss-making listed companies in manufacturing industry at capital market in 2008-2010,this paper analyzed the characteristics of loss of listed companies.Major reasons include the blind investment of management personnel,low operation and management level,blind pursuit of diversified operation,improper stock right structure,weak supervision of government,and imperfect delisting system.Finally,it came up with some countermeasures,including improving quality of management personnel,management personnel selecting proper investment projects,strengthening internal management of enterprise,implementing effective asset rearrangement,setting up effective incentive and restrictive mechanism,bringing into play regulation function of banks,improving delisting mechanism,reducing centralization of state owned stock right,and establishing and improving market information disclosure system.

Study on the Agricultural Biotechnology Innovation Based on the Product Differentiation

Based on product differentiation,this paper researches the innovation of agricultural biotechnology. In the duopoly structure,the company's investment in innovation is affected by the product differentiation,and the greater the difference,the greater the willingness to increase investment and improve quality; at the same time,low innovative cost companies will choose a higher level of investment in innovation and quality. If there is no difference between the products,the companies with high cost of innovation abandon quality competition,and the companies with low cost of innovation " monopolize" the market.

Computed tomography-based multi-organ radiomics nomogram model for predicting the risk of esophagogastric variceal bleeding in cirrhosis

BACKGROUND Radiomics has been used in the diagnosis of cirrhosis and prediction of its associated complications.However,most current studies predict the risk of esophageal variceal bleeding(EVB)based on image features at a single level,which results in incomplete data.Few studies have explored the use of global multi-organ radiomics for non-invasive prediction of EVB secondary to cirrhosis.AIM To develop a model based on clinical and multi-organ radiomic features to predict the risk of first-instance secondary EVB in patients with cirrhosis.METHODS In this study,208 patients with cirrhosis were retrospectively evaluated and randomly split into training(n=145)and validation(n=63)cohorts.Three areas were chosen as regions of interest for extraction of multi-organ radiomic features:The whole liver,whole spleen,and lower esophagus–gastric fundus region.In the training cohort,radiomic score(Rad-score)was created by screening radiomic features using the inter-observer and intra-observer correlation coefficients and the least absolute shrinkage and selection operator method.Independent clinical risk factors were selected using multivariate logistic regression analyses.The radiomic features and clinical risk variables were combined to create a new radiomics-clinical model(RC model).The established models were validated using the validation cohort.BACKGROUND Radiomics has been used in the diagnosis of cirrhosis and prediction of its associated complications.However,most current studies predict the risk of esophageal variceal bleeding(EVB)based on image features at a single level,which results in incomplete data.Few studies have explored the use of global multi-organ radiomics for non-invasive prediction of EVB secondary to cirrhosis.AIM To develop a model based on clinical and multi-organ radiomic features to predict the risk of first-instance secondary EVB in patients with cirrhosis.METHODS In this study,208 patients with cirrhosis were retrospectively evaluated and randomly split into training(n=145)and validation(n=63)cohorts.Three areas were chosen as regions of interest for extraction of multi-organ radiomic features:The whole liver,whole spleen,and lower esophagus–gastric fundus region.In the training cohort,radiomic score(Rad-score)was created by screening radiomic features using the inter-observer and intra-observer correlation coefficients and the least absolute shrinkage and selection operator method.Independent clinical risk factors were selected using multivariate logistic regression analyses.The radiomic features and clinical risk variables were combined to create a new radiomics-clinical model(RC model).The established models were validated using the validation cohort.RESULTS The RC model yielded the best predictive performance and accurately predicted the EVB risk of patients with cirrhosis.Ascites,portal vein thrombosis,and plasma prothrombin time were identified as independent clinical risk factors.The area under the receiver operating characteristic curve(AUC)values for the RC model,Rad-score(liver+spleen+esophagus),Rad-score(liver),Rad-score(spleen),Rad-score(esophagus),and clinical model in the training cohort were 0.951,0.930,0.801,0.831,0.864,and 0.727,respectively.The corresponding AUC values in the validation cohort were 0.930,0.886,0.763,0.792,0.857,and 0.692.CONCLUSION In patients with cirrhosis,combined multi-organ radiomics and clinical model can be used to non-invasively predict the probability of the first secondary EVB.

High-throughput studies and machine learning for design of β titanium alloys with optimum properties

Based on experimental data,machine learning(ML) models for Young's modulus,hardness,and hot-working ability of Ti-based alloys were constructed.In the models,the interdiffusion and mechanical property data were high-throughput re-evaluated from composition variations and nanoindentation data of diffusion couples.Then,the Ti-(22±0.5)at.%Nb-(30±0.5)at.%Zr-(4±0.5)at.%Cr(TNZC) alloy with a single body-centered cubic(BCC) phase was screened in an interactive loop.The experimental results exhibited a relatively low Young's modulus of(58±4) GPa,high nanohardness of(3.4±0.2) GPa,high microhardness of HV(520±5),high compressive yield strength of(1220±18) MPa,large plastic strain greater than 30%,and superior dry-and wet-wear resistance.This work demonstrates that ML combined with high-throughput analytic approaches can offer a powerful tool to accelerate the design of multicomponent Ti alloys with desired properties.Moreover,it is indicated that TNZC alloy is an attractive candidate for biomedical applications.

Construction of MnS/MoS_(2) heterostructure on two-dimensional MoS_(2) surface to regulate the reaction pathways for high-performance Li-O_(2) batteries

The inherent catalytic anisotropy of two-dimensional(2D) materials has limited the enhancement of LiO_(2) batteries(LOBs) performance due to the significantly different adsorption energies on 2D and edge surfaces.Tuning the adsorption strength in 2D materials to the reaction intermediates is essential for achieving high-performance LOBs.Herein,a MnS/MoS_(2) heterostructure is designed as a cathode catalyst by adjusting the adsorption behavior at the surface.Different from the toroidal-like discharge products on the MoS_(2) cathode,the MnS/MoS_(2) surface displays an improved adsorption energy to reaction species,thereby promoting the growth of the film-like discharge products.MnS can disturb the layer growth of MoS_(2),in which the stack edge plane features a strong interaction with the intermediates and limits the growth of the discharge products.Experimental and theoretical results confirm that the MnS/MoS_(2) heterostructure possesses improved electron transfer kinetics at the interface and plays an important role in the adsorption process for reaction species,which finally affects the morphology of Li_2O_(2),In consequence,the MnS/MoS_(2) heterostructure exhibits a high specific capacity of 11696.0 mA h g^(-1) and good cycle stability over 1800 h with a fixed specific capacity of 600 mA h g^(-1) at current density of100 mA g^(-1) This work provides a novel interfacial engineering strategy to enhance the performance of LOBs by tuning the adsorption properties of 2D materials.

Investigation on the temperature-dependent diffusion growth of intermetallic compounds in the Mg-Al-Zn system:Experiment and modeling

With the rapid development of Mg alloys,deeper understanding to the thermodynamic and diffusional kinetic behavior of intermetallic compounds(IMCs)is important for studying the effect of alloying elements to the microstructure evolution.Specially,a systematic quantitative investigation on the diffusional growth of IMCs is of great necessity.However,the works studying the elemental diffusion behaviors of multiple-element IMCs are rare in magnesium alloy systems.The current work takes the ternary Mg-Al-Zn system as research target,and combines the diffusion couple technique,phase stability diagrams,in-situ observation technique and numerical inverse method to investigate the temperature-dependent kinetic coefficients.The parabolic growth constant(PGC)and interdiffusion coefficients for Mg solid-solution phase andγ-Mg_(17)Al_(12),β-Mg_(2)Al_(3),ε-Mg_(23)Al_(30),MgZn_(2),Mg_(2)Zn_(3),τ-Mg_(32)(Zn,Al)49 andφ-Mg_(5)Zn_(2)Al_(2) IMCs in the Mg-Al-Zn alloy system are determined.By comparing the current experimental with calculation results,the rate-controlling factor of the temperature-dependent diffusion growth ofφ,τandεternary IMCs in the Mg-Al-Zn system is further discussed in detail.

Understanding the dehydrogenation properties of Mg(0001)/MgH_(2)(110)interface from first principles

Magnesium hydride is one of the most promising solid-state hydrogen storage materials for on-board application.Hydrogen desorption from MgH_(2) is accompanied by the formation of the Mg/MgH_(2) interfaces,which may play a key role in the further dehydrogenation process.In this work,first-principles calculations have been used to understand the dehydrogenation properties of the Mg(0001)/MgH_(2)(110) interface.It is found that the Mg(0001)/MgH_(2)(110) interface can weaken the Mg-H bond.The removal energies for hydrogen atoms in the interface zone are significantly lower compared to those of bulk MgH_(2).In terms of H mobility,hydrogen diffusion within the interface as well as into the Mg matrix is considered.The calculated energy barriers reveal that the migration of hydrogen atoms in the interface zone is easier than that in the bulk MgH_(2).Based on the hydrogen removal energies and diffusion barriers,we conclude that the formation of the Mg(0001)/MgH_(2)(110) interface facilitates the dehydrogenation process of magnesium hydride.

三维激光雷达技术在高压输电线路巡维中的应用评述

随着三维激光雷达技术的不断进步,因其具有高效率、高精度、非接触、实时性等多种优势,已被逐步应用于高压输电线路巡维领域,但由于相关研究尚处于起步阶段,仍存在着标准不统一、应用方式少等诸多问题。本文首先简要叙述了机载和地面三维激光雷达的工作原理,然后回顾了三维激光雷达技术在架空线路巡维中已验证的主要应用功能,指出了三维激光雷达技术在高压输电线路巡维中具有重要的工程应用价值,最后结合三维激光雷达在架空线路应用中存在的问题,指出应从新功能开发、应用方法的标准化、数据处理的通用性和简便性等方面开展深化研究。

Cu-Nb-Si体系相平衡的实验研究和热力学模拟

通过关键实验、热力学建模和第一性原理计算相结合的方法研究Cu-Nb-Si体系的相平衡关系。制备16种三元合金,采用X射线衍射仪(XRD)和扫描电子显微镜结合X射线能谱仪(SEM-EDS),测定三相和两相区范围,证实三元化合物τ1(Cu_(4)Nb_(5)Si_(4))的存在,同时测定Cu在NbSi_(2)和Nb_(5)Si_(3)相中的溶解度,最终确定Cu-Nb-Si体系在600和700℃的等温截面。基于文献和本工作的实验数据,结合第一性原理计算和CALPHAD方法,利用替代模型和亚点阵模型分别描述溶体相和中间化合物,对Cu-Nb-Si体系进行热力学计算,最终得到一套自洽的热力学参数。通过计算与实验结果相比较,所获得的热力学参数能再现可靠的实验数据。

拉伸变形Al-Si合金中Si颗粒相对于晶粒旋转的原位证据

为确定Si颗粒在拉伸变形过程中是否相对于基体晶粒发生旋转,采用原位拉伸扫描电子显微镜(SEM)和离位背散射电子衍射(EBSD)相结合的方法,研究Al-Si合金在拉伸变形过程中Si颗粒旋转与晶粒旋转之间的关系。通过对比晶粒的EBSD三维取向的平面投影信息与Si颗粒的原位SEM信息,发现Si颗粒在样品表面的平面上具有明显的相对旋转。此外,根据EBSD数据的中心点平均取向差(KAM)分析,发现Si颗粒的较大相对旋转会引入更高密度的几何必需位错(GND),这会在颗粒附近的基体中产生较强的加工硬化效应。总之,Si颗粒的相对旋转度越大,加工硬化效果越强。

地方官员变更与企业金融化--基于地级市市委书记和市长的数据

地方官员变更导致的政策不确定性会对企业行为产生重要影响,它如何影响企业金融资产配置是本文关注的问题。本文以2007~2021年中国沪深两市A股上市公司为研究样本,考察了地方官员变更对企业金融化的影响。研究发现:地方官员变更会显著抑制企业金融资产配置的“投机”动机,从而抑制企业金融化。这一结论在使用多种方法控制内生性和稳健性问题后依然成立。作用机制检验表明,地方官员变更导致企业面临的外部不确定性和外部融资约束削弱了金融资产配置的“投机”动机,从而减少了企业金融资产投资。进一步分析发现,在民营企业、经济发达地区,地方官员变更的影响更强。本文从宏观环境方面丰富了企业金融化的影响因素研究,有助于明晰政策不确定性引起的经济后果,并为采取合理的保障措施提供了政策启示。

三元甲醇辅助质子转移的动力学旁证:硝基联苯酚激发三重态的瞬态吸收研究

羟基芳烃化合物是一种典型“光酸”,在催化合成和生物过程中具有广泛应用、由于激发单重态寿命较短,大多数具有中等激发态酸度的羟基芳烃化合物无法在非水溶剂(如醇)中解离.硝基联苯酚中的硝基可增加激发单重态和三重态间的自旋轨道耦合,通过超快的系间窜越产生最低激发三重态,且具有较高量子产率.本文利用瞬态吸收光谱和动力学分析发现:尽管三重态硝基联苯酚具有中等酸性,但由于其寿命较长,能够与甲醇发生质子转移反应,三重态硝基联苯酚连.续与三个甲醇分子反应形成氢键复合物是质子转移的决速步骤.这--发现表明,具有较长激发态寿命的光酸可以通过具有足够碱性的醇类低聚物诱导其解离.

Ag−Zr−Y体系相平衡的实验测定与热力学计算

利用XRD、SEM−EDS技术研究Ag−Zr−Y体系在800、600和500℃的相平衡。测定Y在Ag_(2)Zr和AgZr相以及Zr在Ag_(51)Y_(14)、Ag_(2)Y和AgY相中的溶解度。在这些相图的等温截面中未发现三元化合物的存在。根据本研究和文献报道的实验数据,采用CALPHAD相图计算方法对Ag−Zr−Y体系进行热力学评估。采用置换溶液模型描述熔体相以及亚点阵模型描述二元化合物。通过优化得到一套自洽且能准确描述Ag−Zr−Y体系的热力学参数。计算几个代表性的等温截面和液相面投影图,并构筑Ag−Zr−Y体系的希尔反应图。计算结果与实验数据相吻合。

Ag-Sn-Zr三元系的热力学模拟和凝固显微组织

采用关键实验和热力学模拟研究Ag–Sn–Zr三元系的相平衡。通过制备22个平衡合金,采用X射线衍射、扫描电子显微镜和能量色散X射线能谱测定Ag–Sn–Zr体系500、700和900℃的等温截面。通过制备8个铸态合金,研究合金的凝固行为。测定Zr、Sn和Ag在Ag–Sn、Ag–Zr和Sn–Zr体系中二元化合物的溶解度,未发现三元化合物存在。基于3个边际二元系的热力学描述及获得的相平衡数据,采用CALPHAD方法对Ag–Sn–Zr体系进行热力学优化,得到一套自洽的热力学参数。计算的等温截面与实验数据吻合较好。计算和构筑Ag–Sn–Zr体系在整个成分范围内的液相面投影图和希尔反应图,模拟Gulliver-Scheil非平衡条件下铸态合金的凝固行为。模拟结果与实验数据相一致。

Effect of melt holding on morphological evolution and sedimentation behavior of iron-rich intermetallic phases in Al-Si-Fe-Mn-Mg alloy

The effect of the melt holding temperature on the morphological evolution and sedimentation behavior of iron-rich intermetallics in Al-7.0 Si-1.0 Fe-1.2 Mn-0.25 Mg alloy was investigated using an optical microscope,scanning electron microscope and differential thermal analyzer.The results show that as the holding temperature decreases,the morphologies of the primary iron-rich phase in matrix change from star-like to polygonal,and the number of the primary phases gradually decreases and disappears at 615°C.Finally,the Chinese script phases with small size,high compact and uniform distribution are obtained.In contrast,the primary iron-rich phases in slag transform into a coarser polygonal shape with lower roundness,and some of them have hollow structures.Furthermore,the area fraction of intermetallics and Fe content in the matrix decrease gradually due to the formation and growth of sludge and subsequent natural sedimentation during melt holding.With the decrease of holding temperature,the main factors hindering the settlement of the primary phases are morphology,size,and density in turn.