Effects of orientation on the fatigue crack growth behaviors of the ZK60 magnesium alloy in air and PBS

Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were conducted.The rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of corrosion.In air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking paths.Compared with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack tip.The corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of specimen.However,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic dissolution.Owing to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS.

蛋白降解靶向嵌合体在非小细胞肺癌治疗中的研究进展

蛋白降解靶向嵌合体(proteolysis targeting chimeria,PROTAC)通过利用泛素蛋白酶体途径实现对靶蛋白降解,颠覆了传统小分子抑制剂的理念。在非小细胞肺癌(non-small cell lung cancer,NSCLC)常见的突变靶点中,PROTAC技术在临床前研究中已经成功实现了鼠类肉瘤病毒癌基因(kirsten rat sarcoma viral oncogene homolog,KRAS)、表皮生长因子受体(epidermal growth factor receptor,EGFR)和间变性淋巴瘤激酶(anaplastic lymphoma kinase,ALK)等蛋白的有效降解。PROTAC药物以其事件驱动的独特优势,有望克服小分子抑制剂产生的获得性耐药的问题,并对难成药靶点展现出良好的治疗潜力,有望成为NSCLC治疗的新策略。

Environmental Pollution and Economic Growth in China: A Test of the Environmental Kuznets Curve

We apply a two pronged approach to analyze the presence of Environmental Kuznets Curve, EKC, in three types of emissions in the People’s Republic of China from 1994 to 2014: a structural breakpoint analysis and a model based test. We apply it to PM2.5, industrial waste and domestic water pollution time series, and find evidence of EKC in all three types of emissions that require appropriate policy.

Relationship between the Environment and Economic Growth in China via Exports: A Perspective of Ecological Impact (2000-2014)

China’s swift and substantial economic growth over the past 20 years has made the country one of the top industrial powers in the world, second only the United States. From the perspective of ecology and the impact on the environment produced by economic and industrial growth, the exports that have driven rapid growth have also resulted in an alarming level of environmental pollution in major Chinese cities. Research has shown that the Chinese government’s investment in bringing down pollution levels has been insufficient and ineffective. The monetary amount allocated for pollution reduction has barely reached 0.15% of the country’s GDP and has failed to meaningfully reverse the effects of industrialization, including increased exports and economic growth rates affecting China’s ecology. The present study investigated China’s ecological situation in terms of the industrial production that has generated its level of exports, with special focus on problems related to water, air, and solid waste. An econometric analysis was conducted to determine the relationship between the main variables. The exports and GDP (dependent variable), air pollution, water pollution, and industrial solid waste (independent variables) were provided by the Institute of Statistics and the Environment Institute of China for this study. The data was managed in Econometric Eviews 7.0 software and yielded an adjusted R2 of 96.09% (high correlation) with an interesting correlation between the exports and three independent variables;after subsequent variable analysis, we found that investments in water and industrial solid waste were not significant (i.e., that said investments have failed to solve the pollution problem). It is necessary to review the Chinese investment policy with special attention to these variables to appropriately respond to China’s ecological crisis.

Composite bilayer films with organic compound-triggered bending properties

Organic compounds are widely used in both industry and daily life,and composite bilayer films with organic compound-triggered bending properties are promising for applications of transducers,soft robotics,and so on.Here,a universal and straightforward strategy to generate composite bilayer films with organic compoundtriggered bending properties is demonstrated.The composite bilayer films with organic compound-triggered bending properties are designed with bilayer structures,in which one layer is a porous polymeric membrane with appropriate solubility parameter that matches the value of organic solvents in order to produce prominent affinity to the solvent molecules,and the other layer is reduced graphene oxide membrane stacked on the porous polymeric membrane as an inert layer for restraining the swelling of the polymeric membrane on one side.Guided by matching the solubility parameters between solvent and polymer,a significant bending curvature of 27.3 cm-1 is obtained in acetone vapor.The results in this study will provide valuable guidance for designing and developing functional composite materials with significant organic compound-triggered bending properties.

有机硝酸酯的大气化学及测量

有机硝酸酯(ONs)是大气中重要的一类含氮有机物。大气中的ONs主要是在氮氧化物存在的条件下,由大气氧化剂和挥发性有机物的光化学反应二次生成,其生消过程与大气氮循环、臭氧以及二次有机气溶胶的形成息息相关;部分气相ONs还可通过气粒分配或多次氧化进入颗粒相,形成颗粒相ONs,进而促进PM_(2.5)的生成,进一步危害人体健康。现阶段,多种化学及光谱学测量技术已成功应用于大气中ONs单物种和总量的浓度测量,并在不同区域开展了多种大气成分的联合外场观测,用于探究氮氧化物参与的ONs生成机制,ONs对区域氮化学的影响以及颗粒相ONs对二次有机气溶胶的贡献等。本文从ONs的生消机制指出其在大气化学中的重要作用,归纳总结了目前已有的ONs测量方法,并指出了不同方法的特点及应用,重点阐述了和ONs相关的室内烟雾箱研究和国内外不同地区的外场观测结果,结合大气化学模型对其在大气化学中的作用进行阐述,指出目前研究中存在的一些不足,以期在后续研究中不断得到完善。

RSPSSL:A novel high-fidelity Raman spectral preprocessing scheme to enhance biomedical applications and chemical resolution visualization

Raman spectroscopy has tremendous potential for material analysis with its molecular fingerprinting capability in many branches of science and technology.It is also an emerging omics technique for metabolic profiling to shape precision medicine.However,precisely attributing vibration peaks coupled with specific environmental,instrumental,and specimen noise is problematic.Intelligent Raman spectral preprocessing to remove statistical bias noise and sample-related errors should provide a powerful tool for valuable information extraction.Here,we propose a novel Raman spectral preprocessing scheme based on self-supervised learning(RSPSSL)with high capacity and spectral fidelity.It can preprocess arbitrary Raman spectra without further training at a speed of~1900 spectra per second without human interference.The experimental data preprocessing trial demonstrated its excellent capacity and signal fidelity with an 88%reduction in root mean square error and a 60%reduction in infinite norm(L__(∞))compared to established techniques.With this advantage,it remarkably enhanced various biomedical applications with a 400%accuracy elevation(ΔAUC)in cancer diagnosis,an average 38%(few-shot)and 242%accuracy improvement in paraquat concentration prediction,and unsealed the chemical resolution of biomedical hyperspectral images,especially in the spectral fingerprint region.It precisely preprocessed various Raman spectra from different spectroscopy devices,laboratories,and diverse applications.This scheme will enable biomedical mechanism screening with the label-free volumetric molecular imaging tool on organism and disease metabolomics profiling with a scenario of high throughput,cross-device,various analyte complexity,and diverse applications.

胎儿左头臂静脉正常与异常超声图像特征及其临床意义

目的探讨产前超声观察胎儿正常与不同类型异常左头臂静脉的图像特征及临床意义。方法收集2018年1月至2021年11月在武汉大学人民医院接受胎儿心脏超声检查并诊断为左头臂静脉异常的胎儿43例,回顾性分析43例胎儿左头臂静脉异常产前超声图像特征及胎儿伴发异常情况,随访染色体检查结果及妊娠结局。另选取正常胎儿248例,测量左头臂静脉内径,分析其与孕龄的相关性。结果43例胎儿左头臂静脉异常包括以下3种类型:左头臂静脉走行异常,其中主动脉弓下走行25例,胸腺内走行6例,食管后走行2例。左头臂静脉缺如7例。左头臂静脉内径异常,其中内径明显增宽2例,内径细小1例。其中19例伴发其他异常,包括右位主动脉弓、法洛四联症、大动脉转位、永存左上腔静脉、完全性心上型肺静脉异位引流等。正常18~34周胎儿左头臂静脉内径范围为(1.9~3.98 mm),与孕龄呈线性正相关关系,回归方程为左头臂静脉内径(mm)=-0.6796+0.1352孕龄。结论产前超声可观察胎儿左头臂静脉的位置、走行及形态,正常左头臂静脉内径随孕龄呈线性增长。加强左头臂静脉各类型异常超声图像特征及临床意义的认识,可为临床咨询提供信息和依据。

Generalized stability criterion for controlling solidification segregation upon twin-roll casting

Macro-and micro-segregation formed upon twin-roll casting(TRC)can be inherited from sub-rapid solid-ification to solid-state transformation,even to plastic deformation,thus deteriorating drastically mechan-ical properties of as-produced thin sheets.Although many works focusing mainly on controlling fields of thermal,concentration and convection have been reported,how to control artificially and quantitatively the segregation using a theoretical connection between processing parameters and solidification models,has not been realized,yet.Regarding it,a systematical framework integrating non-equilibrium dendritic growth and overall solidification kinetics with the TRC parameters,was constructed applying a general-ized stability(GS)conception deduced from transient thermodynamic driving force△G^(t)and transient ki-netic energy barrier Q_(eff)^(t)evolving upon solidification.Departing from this framework considering synergy of thermodynamics and kinetics(i.e.,thermo-kinetic synergy),a criterion of high△G^(t)-high GS guaranteed that the macro(i.e.,the centerline)and the micro(i.e.,the edge)segregation can be suppressed by in-creasing△G^(t)and GS at the beginning and the ending stage of sub-rapid solidification,respectively.This typical thermo-kinetic combination producing the microstructure can be inherited into the plastic de-formation,as reflected by corresponding strength-ductility combinations.This work realized quantitative controlling of TRC by a theoretical connection between processing parameters and solidification models,where,an optimization for sub-rapid solidification segregation using the GS conception including△G^(t)and Q_(eff)^(t)has been performed.

Pyrotinib in HER2 heterogeneously mutated or amplified advanced non-small cell lung cancer patients:a retrospective real-world study(PEARL)

Human epidermal growth factor receptor 2(HER2)amplification or activating mutations are found in 1.6%–4%of non-small cell lung cancer(NSCLC).Pyrotinib has been reported to have better potency in NSCLC patients with HER2 exon 20 insertion(ex20ins)mutations;however,more clinical evidence is urgently needed to guide pyrotinib-based therapy in NSCLC with HER2 amplification or heterogeneous mutations.We retrospectively analyzed advanced NSCLC patients with HER2 amplification or mutations who were treated with pyrotinib-based therapy between September 25,2018 and October 30,2020 in our hospital.Molecular dynamics simulation was used to explore the bioactive conformation and binding mechanisms of pan-ErbB tyrosine kinase inhibitors(TKIs)including pyrotinib for different HER2 ex20ins variants.In this study,79 eligible patients were included with 70 ex20ins variants,6 missense mutations and 3 primary HER2 amplifications identified.A775_G776insYVMA insertion was the most common observed subtype.The median progression-free survival(mPFS)was 5.8(95%CI:4.1–7.4)months.Use of pyrotinib-based therapy in first-/second-line settings showed a significantly better prognosis than that observed in third-line settings or above(mPFS:9.1 vs.4.4 months;P=0.0003).Compared with HER2 amplification and exon 20 non-YVMA insertion variants,patients with HER2 missense mutations had a visible mPFS benefit(12.2 vs.6.8 vs.5.2 months).Computational docking simulations revealed that pyrotinib failed to interact with the specific insertion variant P780_Y781insGSP.These results indicated that pyrotinib-based therapy exhibited good anti-tumor activity and acceptable safety profile in HER2-altered advanced NSCLC.

Influence of Twinning Texture on the Corrosion Fatigue Behavior of Extruded Magnesium Alloys

Bio-magnesium alloys have received great attention due to their degradability and biocompatibility.Corrosion fatigue failure is a huge challenge in vivo for bio-magnesium alloy implants.Understanding the eff ects of twinning textures on the corrosion fatigue of magnesium alloys is meaningful for the applications.In the current study,pre-compression strains of 2%and 4%were carried out on extruded rods.The effects of twinning texture on the corrosion performance and corrosion fatigue resistance were investigated.The hydrogen evolution tests indicated that twinning texture enhanced the corrosion resistance of longitudinal cross section by improving uniformity of surface energy.The results of corrosion fatigue tests indicated that the differences in mechanical damage caused by twinning texture dominated the corrosion fatigue behavior under high stress amplitude.The secondary cracks of surface deteriorated the corrosion fatigue resistance of the original specimens under low stress amplitude.The compact corrosion film and the re-passivation of matrix suppressed the hydrogen induced cracking,thereby improving the corrosion fatigue resistance of the pre-compression specimens.