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关键词： 钎焊热循环   GH4169   显微组织   力学性能   缺口敏感性  

摘要： 为探究不同峰值温度的多次钎焊热循环对GH4169合金组织与性能的影响规律,以GH4169合金为研究对象,系统研究了钎焊热循环工艺对GH4169合金的析出相、晶粒尺寸、拉伸性能及持久性能的影响。结果表明:δ相的析出量随热循环温度的升高呈下降趋势,形态由针状转变为棒状后再转变为颗粒状;在970~1010℃范围内,晶粒尺寸变化不大,而当温度升高至1020℃以上时,晶粒显著长大。抗拉强度和硬度均随热循环温度的升高先增加后降低,并在1010℃时达到峰值,这主要得益于该温度下适量δ相溶解与γ″、γ′强化相的充分析出,而晶粒尺寸并未发生明显粗化;室温冲击韧性在不同的热循环范围具有不同的变化趋势,970~990℃范围内随温度升高而降低,这是由δ相的部分形态由针状转变为棒状所导致;990~1010℃范围内随着温度升高而增加,是由δ相溶解,无强化相析出带消失所导致,而继续增加热循环温度导致冲击韧性下降则是由于晶粒尺寸长大。持久寿命随热循环温度的升高先缩短后延长,在990~1000℃范围内达到最低点,这是由δ相的部分形态由针状转变为棒状,促进微孔形核,降低合金的抗蠕变能力所致。当温度进一步升高至1020℃以上时,γ″强化相大量析出并辅以晶粒显著长大,合金的蠕变性能得以显著改善,但针状δ相含量大幅度降低导致缺口敏感性增强。综合考虑力学性能与缺口敏感性,建议在1010℃左右进行钎焊热循环,可获得较为平衡的强度与持久性能;若服役环境对缺口敏感性要求较高,可选择970~980℃的热循环温度,以降低蠕变失效风险。

关键词： artificial intelligence   coronary artery disease   ECG   noninvasive diagnostics   AI   artificial intelligence   CAD   coronary artery disease   ECG   electrocardiogram/electrocardiography   NPV   negative predictive value   PPV   positive predictive value  

摘要： The current gold standard for the diagnosis of coronary artery disease (CAD) is invasive angiography; however, it is an invasive procedure. Therefore, we developed an artificial intelligence model designed to predict significant CAD from a resting digital 12-lead electrocardiogram (ECG).

关键词： cardiac computed tomography   cardiac magnetic resonance   circulation   coronary artery disease   coronary flow reserve   echocardiography   microvascular dysfunction   myocardial blood flow   myocardial perfusion imaging   positron emission tomography   AIF   arterial input function   CAD   coronary artery disease   CMD   coronary microvascular dysfunction   CMR   cardiac magnetic resonance   CT   computed tomography   CTA   computed tomographic angiography   LGE   late gadolinium enhancement   MBF   myocardial blood flow   MCE   myocardial contrast echocardiography   MFR   myocardial flow reserve   PET   positron emission tomography   ROC   receiver-operating characteristic   SPECT   single-photon emission computed tomography   UEA   ultrasound-enhancing agent  

摘要： Positron emission tomographic myocardial perfusion imaging in conjunction with tracer-kinetic modeling affords the concurrent assessment of myocardial blood flow (MBF) in mL/min/g of tissue. Cardiac magnetic resonance, computed tomography, and echocardiography are emerging technologies capable of MBF quantification. The noninvasive evaluation and quantification of MBF during hyperemia and at rest and corresponding myocardial flow reserve expand the realm of conventional myocardial perfusion imaging from detection of the most advanced, and flow-limiting, epicardial lesions in multivessel coronary artery disease (CAD) to less severe intermediate epicardial lesions, accurate delineation of the extent and severity of ischemic burden in multivessel CAD, detection of diffuse ischemia attributable to CAD or at coronary arteriolar level such as in hypertrophic cardiomyopathy, transplantation vasculopathy, and coronary microvascular dysfunction in its classical and/or endogen forms. Apart from improving the diagnostic scope in ischemic heart disease, the additional quantitation of MBF also affords the contingency to follow-up on treatment success of therapeutic interventions, risk factor modifications, and/or lifestyle changes likely to improve long-term cardiovascular outcomes. Standardized algorithms for each imaging modality in the diagnosis and reporting of ischemia heart disease appear critical for optimized diagnosis and treatment decisions in such patients. In this respect, the convened expert panel strives to provide a concise overview of the pathophysiology of ischemic heart disease and its noninvasive assessment with different imaging modalities that may be pivotal for the diagnosis of various pattern types of ischemic heart disease, as well as individualized and image-guided patient care likely to further optimize cardiovascular outcome.

关键词： Metrology   telecentric vision   YOLO   imaging-to-CAD reconstruction  

摘要： This paper presents an automated imaging-to-CAD reconstruction system that combines telecentric vision and deep learning for high-accuracy digital reconstruction of printed circuit boards(PCBs).The framework integrates a telecentric camera with a Cartesian scanning platform to capture distortion-free,high-resolution PCB images,which are stitched into a single orthographic composite.A YOLO-based detection model,trained on a dataset of 270 PCB images across 23 component classes with data augmentation,identifies and localizes electronic components with a mean average precision of *** components are automatically matched to corresponding 3D CAD models from a part library and assembled within a Fusion 360 environment,producing a 3D digital *** results show a similarity score of 0.894 and dimensional deviations below 2%,outperforming both SensoPart image measurement and manual vernier *** proposed approach bridges optical metrology and CAD automation,providing a scalable solution for AI-assisted reverse engineering,digital archiving,and intelligent manufacturing.

关键词： 结直肠癌   神经纤毛蛋白1   E-钙黏蛋白   临床意义  

摘要： 目的:通过检测神经纤毛蛋白1(NRP-1)和E-钙黏蛋白(E-cad)在结直肠癌中的表达,探讨其临床意义。方法:选取2016年6月1日至2018年6月30日我院手术切除的结直肠腺癌标本112例,应用免疫组织化学方法检测NRP-1与E-cad的表达,并分析与临床病理资料及生存资料的关系,并进行Kaplan-Meier生存分析、Cox回归单因素及多因素分析。结果:NRP-1在结直肠癌组织和癌旁组织中的阳性表达率为58.04%(65/112)和18.75%(21/112),差异有统计学意义(P<0.001);E-cad在结直肠癌组织和癌旁组织中的阳性表达率为29.46%(33/112)和81.25%(91/112),差异有统计学意义(P<0.001)。NRP-1在TNM(Ⅲ+Ⅳ)期组、有淋巴结转移组、脉管浸润组中的表达明显高于TNM(Ⅰ+Ⅱ)期组(P=0.001)、无淋巴结转移组(P=0.001)、无脉管浸润组(P=0.024),差异均有统计学意义;E-cad在TNM(Ⅲ+Ⅳ)期组、有淋巴结转移组中的表达明显低于TNM(Ⅰ+Ⅱ)期组(P=0.001)、无淋巴结转移组(P=0.001),差异均有统计学意义;而NRP-1和E-cad的表达与性别、年龄、部位、肿瘤大小、组织学分级均无明显关系(P>0.05)。NRP-1和E-cad的表达呈负相关(P<0.010,r=-0.55)。生存分析结果显示:NRP-1阳性表达组或E-cad阴性表达组5年生存率低(P<0.05),NRP-1阳性和E-cad阴性表达组生存率最差。Cox回归单因素分析显示,淋巴结转移、TNM分期Ⅲ+Ⅳ期、NRP-1阳性表达、E-cad阴性表达是预后不良的危险因素;多因素分析显示:淋巴结转移、TNM分期Ⅲ+Ⅳ期、NRP-1阳性表达是结直肠癌患者的独立预后因素。结论:在结直肠癌组织中,NRP-1表达上调,E-cad表达下调,NRP-1可能通过上皮-间质转化在结直肠癌的发生发展过程中发挥了作用,可作为预后评估的生物学指标。

关键词： metformin   coronary artery disease   metabolic syndrome   nonischemic myocardium   AKT   protein kinase B   AMPK   AMP-activated protein kinase   BAD   Bcl2-associated agonist of cell death   CAD   coronary artery disease   dV/dt max   maximal rate of volume change   EV   extracellular vesicle   MET   metformin   MS   metabolic syndrome   LCx   left circumflex artery   mTOR   mammalian target of rapamycin   p-AKT   phosphorylated protein kinase B   p-AMPK   phosphorylated AMP-activated protein kinase   p-BAD   phosphorylated BCL2-associated agonist of cell death   p-mTOR   phosphorylated mammalian target of rapamycin   T2DM   type 2 diabetes mellitus   TUNEL   transferase dUTP nick end labeling  

摘要： This study evaluated the effects of metformin (MET) on nonischemic myocardium in a large animal model of coronary artery disease and metabolic syndrome (MS). Although prior work has shown MET improves perfusion and function in ischemic tissue, this study assessed whether its cardioprotective effects extend to nonischemic regions.

关键词： profiling long noncoding rnas   ferroptosis   EGFR ERK signaling   cad   transcription factor early growth response   long noncoding rnas   essence   colorectal cancer  

摘要： Epidermal growth factor receptor/mitogen-activated protein kinase(EGFR/MAPK)signaling is highly activated in various types of *** long noncoding RNAs induced by this pathway and their roles in colorectal cancer(CRC)have not been fully *** this study,based on the profiling of long noncoding RNAs triggered by EGFR/MAPK signaling,we identified that ESSENCE(EGF[epidermal growth factor]Signal Sensing CAD’s Effect;ENST00000415336),which is mediated by the transcription factor early growth response factor 1,functions as a potent oncogenic molecule that predicts poor prognosis in ***,ESSENCE directly interacts with carbamoyl-phosphate synthetase 2,aspartate transcarbamylase,and dihydroorotase(CAD)and competitively attenuates CAD degradation mediated by its newly discovered E3 ligase KEAP1,thereby suppressing ferroptosis and promoting CRC ***,combinational treatment of the mitogen-activated extracellular signal-regulated kinase inhibitor selumetinib and ferroptosis inducer sulfasalazine synergistically suppresses ESSENCE-high CRC in a patient-derived xenograft mouse *** together,these findings demonstrate the crucial role of ESSENCE in mediating CRC progression by regulating CAD stabilization and suggest a therapeutic strategy of targeting the ESSENCE-CAD axis in CRC.

关键词： Fe-32Ni-5Co超因瓦合金   相变循环   马氏体相变温度(Ms)   马氏体逆转变   宽温域  

摘要： 通过“奥氏体→马氏体→奥氏体”的相变循环热处理,对试样进行840℃水淬+350℃回火的预处理,随后进行-80℃深冷诱发马氏体,最后在400~700℃进行热处理,探究马氏体逆转变过程中Fe-32Ni-5Co超因瓦合金组织结构的变化及对膨胀性能的影响。利用金相显微镜、扫描电镜(SEM)、电子背散射衍射(EBSD)及透射电镜(TEM),观察合金的组织结构变化及元素分布情况。结果表明,随着热处理温度的升高(400~700℃),马氏体逐渐逆转变为奥氏体,且合金内部位错及小角度晶界逐渐减少,至700℃时合金组织完全转变为奥氏体结构,获得的组织中无明显位错残留。并且该相变循环过程中发生溶质原子的重新分配及组织重构,使合金的抗相变能力得到提升,700℃热处理后的合金马氏体相变起始温度(Ms,-61℃)比未经处理的合金(-42℃)降低19℃,而马氏体逆转变起始温度从448℃升高到467℃。同时相变循环热处理后合金的热膨胀系数(CTE=1.277×10^(-6)℃^(-1))依然保持较低水平。

关键词： PCD-CT   CCTA   CAD   Stenosis assessment   Image quality  

摘要： Coronary CT angiography (CCTA) is a key non-invasive tool for evaluating coronary artery disease (CAD). While energy-integrating detector CT (EID-CT) offers high negative predictive value (NPV), its positive predictive value (PPV) is limited in heavily calcified vessels. Photon-counting detector CT (PCD-CT), with higher spatial resolution and reduced blooming, may enhance diagnostic performance. Current PCD-CT systems provide both standard-resolution (SR) and ultra-high-resolution (UHR) modes, but the clinical impact of these modes remains under investigation.

关键词： Ceramic   Zirconia   CAD/CAM   Flexure strength  

摘要： Even though improvements in CAD/CAM technology have allowed the milling protocol to be modified according to specific treatment requirements, it remains unclear how different protocols affect the surface quality and mechanical properties of the final restoration. This study aims to evaluate the effect of the CAD/CAM milling protocol on the topography, flexural strength, and reliability of 3 mol% yttria partially stabilized zirconia (3Y-PSZ).