Coupling physics in machine learning to investigate the solution behavior of binary Mg alloys

The solution behavior of a second element in the primary phase(α(Mg))is important in the design of high-performance alloys.In this work,three sets of features have been collected:a)interaction features of solutes and Mg obtained from first-principles calculation,b)intrinsic physical properties of the pure elements and c)structural features.Based on the maximum solid solubility values,the solution behavior of elements inα(Mg)are classified into four types,e.g.,miscible,soluble,sparingly-soluble and slightly-soluble.The machine learning approach,including random forest and decision tree algorithm methods,is performed and it has been found that four features,e.g.,formation energy,electronegativity,non-bonded atomic radius,and work function,can together determine the classification of the solution behavior of an element inα(Mg).The mathematical correlations,as well as the physical relationships among the selected features have been analyzed.This model can also be applied to other systems following minor modifications of the defined features,if required.

Synthesis and Bioactivity of Natural Occurring Petasin-Like Derivatives as Antitumor Agents

Petasin is a potential antitumor against human neuroblastoma cell SK-N-SH by inhibiting the ERK1/2 phosphorylation. In view of its great activity and new antiproliferative mechanisms, a series of petasin derivatives were designed and synthesized, which showed great antiproliferative activity. Among them compounds 1h and 1f were more effective against SK-N-SH cells than petasin with the IC50 values of 0.87 and 2.63 μM, respectively.

High‑Performance Flexible Microneedle Array as a Low‑Impedance Surface Biopotential Dry Electrode for Wearable Electrophysiological Recording and Polysomnography

Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.

DDIT4通过p53和MAPK通路促进胃癌增殖和肿瘤发生

背景与目的胃癌(gastric cancer,GC)是世界上最常见的恶性肿瘤之一,在我国尤为常见。DNA损伤诱导转录因子4(DNAdamage-inducibletranscript4,DDIT4)是哺乳动物雷帕霉素靶蛋白抑制因子,由多种细胞应激诱导产生;然而,它在胃癌中的关键作用仍然未知。本研究旨在探讨DDIT4与胃癌发展的关系及其作用机制。方法我们采用蛋白免疫印迹法、实时聚合酶链反应、免疫组化或免疫荧光法检测DDIT4在胃癌细胞和组织中的表达情况。采用高通量筛选、细胞计数试剂盒-8、克隆形成和体内成瘤实验检测细胞增殖情况。采用流式细胞术检测细胞凋亡和细胞周期分布情况。结果 DDIT4在胃癌细胞和组织中表达上调。在胃癌细胞中下调DDIT4表达可抑制体外和体内的细胞增殖并增强了5-氟尿嘧啶诱导的细胞凋亡和细胞周期阻滞。与之相反,在正常胃上皮细胞中DDIT4的异位表达促进了细胞增殖、降低了化疗敏感性。进一步研究表明,丝裂原活化蛋白激酶和p53信号通路参与抑制细胞增殖并在DDIT4下调后增强化疗敏感性。结论 DDIT4促进了胃癌细胞增殖和肿瘤发生,为研究DDIT4在人类胃癌发生、发展中的作用提供了新思路。

Study on a Dual Embedded Discrete Fracture Model for Fluid Flow in Fractured Porous Media

Simulation of fluid flow in the fractured porous media is very important and challenging.Researchers have developed some models for fractured porous media.With the development of related research in recent years,the prospect of embedded discrete fracture model(EDFM)is more and more bright.However,since the size of the fractures in the actual reservoir varies greatly,a very fine grid should be used which leads to a huge burden to the computing resources.To address this challenge,in the present paper,an upscaling based model is proposed.In this model,the flow in large-scale fractures is directly described by the EDFM while that in the small-scale fractures is upscaled through local simulation by EDFM.The EDFM is used to simulate the large-and small-scale fractures independently two times,so the new model is called dual embedded discrete fracture model(D-EDFM).In this paper,the detailed implementation process of D-EDFM is introduced and,through test cases,it is found the proposed model is a feasible method to simulate the flow in fractured porous media.

The advance of magnetic diagnostics system in support of EAST long-pulsed operation

In EAST long-pulsed discharge(hundreds of seconds),electric magnetic diagnosis(EMD)is very important,since EMD not only monitors tokamak security status but also provides accurate measurement accuracy for reconstruction of the plasma boundary.To avoid current measurement drift,a fiber optic current sensor,based on the Faraday effect,is developed and used for poloidal and plasma current feedback control for the first time,relative current measurement accuracy is within 0.5%.To ensure plasma boundary control accuracy,a detailed set of magnetic measurement calibration methods is developed before the plasma discharge.The maximum relative error is less than 1%,the corresponding control accuracy is within 1 cm.To minimize integrator drift error,a long-pulse integrator test is essential,the corresponding drift error needs to be subtracted in plasma control system.Besides,the saddle coil and Mirnov coil not only help to detect MHD issues,but are also utilized for plasma disruption prediction during the long-pulse discharge.

DDIT4 promotes gastric cancer proliferation and tumorigenesis through the p53 and MAPK pathways

Background:Gastric cancer(GC)is one of the most common malignancies worldwide,particularly in China.DNA damage-inducible transcript 4(DDIT4)is a mammalian target of rapamycin inhibitor and is induced by various cellular stresses;however,its critical role in GC remains poorly understood.The present study aimed to investigate the poten-tial relationship and the underlying mechanism between DDIT4 and GC development.Methods:We used western blotting,real-time polymerase chain reaction,and immunohistochemical or immunoflu-orescence to determine DDIT4 expression in GC cells and tissues.High-content screening,cell counting kit-8 assays,colony formation,and in vivo tumorigenesis assays were performed to evaluate cell proliferation.Flow cytometry was used to investigate cell apoptosis and cell cycle distribution.Results:DDIT4 was upregulated in GC cells and tissue.Furthermore,downregulating DDIT4 in GC cells inhibited proliferation both in vitro and in vivo and increased 5-fluorouracil-induced apoptosis and cell cycle arrest.In contrast,ectopic expression of DDIT4 in normal gastric epithelial cells promoted proliferation and attenuated chemosensitivity.Further analysis indicated that the mitogen-activated protein kinase and p53 signaling pathways were involved in the suppression of proliferation,and increased chemosensitivity upon DDIT4 downregulation.Conclusion:DDIT4 promotes GC proliferation and tumorigenesis,providing new insights into the role of DDIT4 in the tumorigenesis of human GC.

A NEW APPROACH TO HOLISTIC NITROGEN MANAGEMENT IN CHINA

Since the 1980s,the widespread use of N fertilizer has not only resulted in a strong increase in agricultural productivity but also caused a number of environmental problems,induced by excess reactive N emissions.A range of approaches to improve N management for increased agricultural production together with reduced environmental impacts has been proposed.The 4R principles(right product,right amount,right time and right place)for N fertilizer application have been essential for improving crop productivity and N use efficiency while reducing N losses.For example,site-specific N management(as part of 4R practice)reduced N fertilizer use by 32%and increased yield by 5%in China.However,it has not been enough to overcome the challenge of producing more food with reduced impact on the environment and health.This paper proposes a new framework of food-chainnitrogen-management(FCNM).This involves good N management including the recycling of organic manures,optimized crop and animal production and improved human diets,with the aim of maximizing resource use efficiency and minimizing environmental emissions.FCNM could meet future challenges for food demand,resource sustainability and environmental safety,key issues for green agricultural transformation in China and other countries.

Fully solution processed liquid metal features as highly conductive and ultrastretchable conductors

Liquid metal represents a highly conductive and inherently deformable conductor for the development of stretchable electronics.The widespread implementations of liquid metal towards functional sensors and circuits are currently hindered by the lack of a facile and scalable patterning approach.In this study,we report a fully solution-based process to generate patterned features of the liquid metal conductor.The entire process is carried out under ambient conditions and is generally compatible with various elastomeric substrates.The as-prepared liquid metal feature exhibits high resolution(100μm),excellent electrical conductivity(4.15×10^(4)S cm^(−1)),ultrahigh stretchability(1000%tensile strain),and mechanical durability.The practical suitability is demonstrated by the heterogeneous integration of light-emitting diode(LED)chips with liquid metal interconnects for a stretchable and wearable LED array.The solution-based technique reported here is the enabler for the facile patterning of liquid metal features at low cost,which may find a broad range of applications in emerging fields of epidermal sensors,wearable heaters,advanced prosthetics,and soft robotics.

Enhanced YOLOv5 network-based object detection(BALFilter Reader)promotes PERFECT filter-enabled liquid biopsy of lung cancer from bronchoalveolar lavage fluid(BALF)

Liquid biopsy of cancers,detecting tumor-related information from liquid samples,has attracted wide attentions as an emerging technology.Our previously reported large-area PERFECT(Precise-Efficient-Robust-Flexible-Easy-ControllableThin)filter has demonstrated competitive sensitivity in recovering rare tumor cells from clinical samples.However,it is time-consuming and easily biased to manually inspect rare target cells among numerous background cells distributed in a large area(Φ≥13 mm).This puts forward an urgent demand for rapid and bias-free inspection.Hereby,this paper implemented deep learning-based object detection for the inspection of rare tumor cells from large-field images of PERFECT filters with hematoxylin-eosin(HE)-stained cells recovered from bronchoalveolar lavage fluid(BALF).CenterNet,EfficientDet,and YOLOv5 were trained and validated with 240 and 60 image blocks containing tumor and/or background cells,respectively.YOLOv5 was selected as the basic network given the highest mAP@0.5 of 92.1%,compared to those of CenterNet and EfficientDet at 85.2%and 91.6%,respectively.Then,tricks including CIoU loss,image flip,mosaic,HSV augmentation and TTA were applied to enhance the performance of the YOLOv5 network,improving mAP@0.5 to 96.2%.This enhanced YOLOv5 network-based object detection,named as BALFilter Reader,was tested and cross-validated on 24 clinical cases.The overall diagnosis performance(~2 min)with sensitivity@66.7%±16.7%,specificity@100.0%±0.0%and accuracy@75.0%±12.5%was superior to that from two experienced pathologists(10–30 min)with sensitivity@61.1%,specificity@16.7%and accuracy@50.0%,with the histopathological result as the gold standard.The AUC of the BALFilter Reader is 0.84±0.08.Moreover,a customized Web was developed for a user-friendly interface and the promotion of wide applications.The current results revealed that the developed BALFilter Reader is a rapid,bias-free and easily accessible AI-enabled tool to promote the transplantation of the BALFilter technique.This work can easily expand to other cytopathological diagnoses and improve the application value of micro/nanotechnology-based liquid biopsy in the era of intelligent pathology.

大气细颗粒物中环境持久性自由基的分子特征与形成机理的研究

Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular characteristics of EPFRs remain unknown.Here,we report a surrogate method to characterize EPFRs in real ambient samples using mass spectrometry.The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons(OxPAH)that interconvert with oxygen-centered EPFR(OC-EPFR).We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse quinones,whose diversity is strongly associated with OC-EPFR levels.Both atmospheric oxidation and combustion contributed to OC-EPFR formation.Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources.Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs,offering a way to track the development and evolution of aerosol particles in the environment.

Prevalence of Autism Spectrum Disorder in China:A Nationwide Multi-center Population-based Study Among Children Aged 6 to 12 Years

This study aimed to obtain the first national estimate of the prevalence of autism spectrum disorder(ASD) in Chinese children.We targeted the population of 6 to 12-year-old children for this prevalence study by multistage convenient cluster sampling.The Modified Chinese Autism Spectrum Rating Scale was used for the screening process.Of the target population of 142,086 children,88.5%(n=125,806) participated in the study.A total of 363 children were confirmed as having ASD.The observed ASD prevalence rate was 0.29%(95% CI:0.26%-0.32%) for the overall population.After adjustment for response rates,the estimated number of ASD cases was867 in the target population sample,thereby achieving an estimated prevalence of 0.70%(95% CI:0.64%-0.74%).The prevalence was significantly higher in boys than in girls(0.95%;95% CI:0.87%-1.02% versus 0.30%;95%CI:0.26%-0.34%;P <0.001).Of the 363 confirmed ASD cases,43.3% were newly diagnosed,and most of those(90.4%) were attending regular schools,and 68.8% of the children with ASD had at least one neuropsychiatric comorbidity.Our findings provide reliable data on the estimated ASD prevalence and comorbidities in Chinese children.

Agriculture Green Development: a model for China and the world

Realizing sustainable development has become a global priority.This holds,in particular,for agriculture.Recently,the United Nations launched the Sustainable Development Goals(SDGs),and the Nineteenth National People’s Congress has delivered a national strategy for sustainable development in China—realizing green development.The overall objective of Agriculture Green Development(AGD)is to coordinate"green"with"development"to realize the transformation of current agriculture with high resource consumption and high environmental costs into a green agriculture and countryside with high productivity,high resource use efficiency and low environmental impact.This is a formidable task,requiring joint efforts of government,farmers,industry,educators and researchers.The innovative concept for AGD will focus on reconstructing the whole crop-animal production and food production-consumption system,with the emphasis on high thresholds for environmental standards and food quality as well as enhanced human well-being.This paper addresses the significance,challenges,framework,pathways and potential solutions for realizing AGD in China,and highlights the potential changes that will lead to a more sustainable agriculture in the future.Proposals include interdisciplinary innovations,whole food chain improvement and regional solutions.The implementation of AGD in China will provide important implications for the countries in developmental transition,and contribute to global sustainable development.

大宽跨比独塔斜拉桥超宽正交异性钢箱结合梁受力分析

独塔斜拉桥的几何非对称特性导致其应力和变形不同于一般同类桥,大宽跨比正交异性钢箱梁的薄壁结构使得其受力及变形更为复杂,用常规方法难以精确给出变形和应力值。贾鲁河大桥即是这样一个例子,而且复杂性进一步增加。120 m的主跨分成三部分:从主塔开始的100m是正交异性钢箱梁,紧接的8m过渡段与12m的混凝土梁段衔接,后者系从对岸墩台伸出的悬臂段。由于钢箱梁宽度达54.8m,且未直接支撑在对岸桥墩上,而是通过一个8m长、54.8m宽的过渡梁段间接与混凝土伸臂梁连接,属于小范围内刚度不同的三种材料的连接,由此形成的两道连接缝不但削弱了结构的整体性,而且使对准和控制环节多,进一步增加了施工控制的难度。研究表明:钢箱梁横向变形基本一致,最大横向变形相对差值为-2.8 mm,施工时可不设横向预拱度;自重作用引起的钢箱梁最大Mises应力为93.7 MPa,二期恒载和活载作用下的最大Mises应力约为自重引起的1/4,表明钢箱梁应力具有较大的安全富余度;当U肋高度在260~320 mm范围变化时,桥面系位移变化幅度不超过5%,桥面板最大应力变化幅度不超过8%,此范围内U肋高度变化对桥面系位移和应力的影响均较小,内在原因是U肋的高低变化与横梁能提供的刚度是互补的,正好说明该正交异性钢箱梁具有显著的板的特征,设计上宜采用此范围内的U肋高度。