图案化聚合物刷辅助金属无电沉积制备铜图案及应用

提出了聚合物刷辅助金属选择性沉积制备铜图案的方法。利用聚多巴胺(PDA)将光引发表面原子转移自由基聚合(ATRP)引发剂接枝到硅基体表面,以甲基丙烯酰氧乙基三甲基氯化铵(METAC)为反应单体,通过数字微镜器件(DMD)调控光辐照选择性引发ATRP反应制备了离子型PMETAC聚合物刷图案,采用X射线光电子能谱仪(XPS)、光学显微镜和原子力显微镜(AFM)对所制备图案的化学组成、几何形状及表面形貌进行了表征分析,结果表明图案化PMETAC刷的成功制备。以PMETAC刷图案化表面为模板,通过PMETAC刷末端带正电的季铵盐基团与活性离子[PdCl4]2-进行离子交换将金属催化剂固定在聚合物刷分子链上以诱导铜沉积,光学显微镜和XPS的分析结果表明了铜在PMETAC聚合物刷区域的选择性沉积。对不同尺寸铜图案表面的电性能进行研究,设计了通过硅片表面铜图案连接导线以点亮发光二极管的实验,结果表明该方法制备的铜图案具有优异的导电性。相关研究工作为图案化聚合物刷辅助金属沉积技术在复杂电路制备领域的应用提供了借鉴。

A developed ant colony algorithm for cancer molecular subtype classification to reveal the predictive biomarker in the renal cell carcinoma

Background:Recently,researchers have been attracted in identifying the crucial genes related to cancer,which plays important role in cancer diagnosis and treatment.However,in performing the cancer molecular subtype classification task from cancer gene expression data,it is challenging to obtain those significant genes due to the high dimensionality and high noise of data.Moreover,the existing methods always suffer from some issues such as premature convergence.Methods:To address those problems,we propose a new ant colony optimization(ACO)algorithm called DACO to classify the cancer gene expression datasets,identifying the essential genes of different diseases.In DACO,first,we propose the initial pheromone concentration based on the weight ranking vector to accelerate the convergence speed;then,a dynamic pheromone volatility factor is designed to prevent the algorithm from getting stuck in the local optimal solution;finally,the pheromone update rule in the Ant Colony System is employed to update the pheromone globally and locally.To demonstrate the performance of the proposed algorithm in classification,different existing approaches are compared with the proposed algorithm on eight high-dimensional cancer gene expression datasets.Results:The experiment results show that the proposed algorithm performs better than other effective methods in terms of classification accuracy and the number of feature sets.It can be used to address the classification problem effectively.Moreover,a renal cell carcinoma dataset is employed to reveal the biological significance of the proposed algorithm from a number of biological analyses.Conclusion:The results demonstrate that CAPS may play a crucial role in the occurrence and development of renal clear cell carcinoma.

Lack of Tocopherol Inhibits Rice Growth by Triggering an Ectopic Stress Response and the Accumulation of DELLA Protein

Although tocopherols are essential for rice development,the molecular details by which their absence affects development remain to be determined.To study how tocopherols function during rice development,we performed a transcriptome deep sequencing(RNA-seq)analysis of the rice cultivar Nipponbare(Nip)and the tocopherol-deficient mutant small grain and dwarf 1-2(sgd1-2).We identified 563 differentially expressed genes that were enriched in Gene Ontology categories associated with metabolism,stress,cellular responses,and transcriptional regulation.We determined that the total fatty acid composition of Nip and sgd1-2 was comparable,although cell membrane penetrability in sgd1-2 was significantly higher than in Nip under optimal growth conditions,indicating that tocopherol deficiency induces cell membrane damage.The expression levels of dehydration-responsive element binding 1(DREB1)genes and free proline content in sgd1-2 were also higher than those in Nip.We also showed that the DELLA protein SLENDER RICE1(SLR1)accumulated in sgd1-2,resulting in significant changes in the global transcriptome.Our study confirms that the lack of tocopherol accumulation in rice induced ectopic stress responses and limited growth by enhancing SLR1 abundance through increasing SLR1 transcript levels.These results provide new insights into tocopherol during rice development.

A new flavonoid with a benzoic acid substituent from Selaginella uncinata

6-(5-Carboxyl-2-methoxyphenyl )-apigenin (1 ) ，新 flavonoid，从 Selaginella uncinata (Desv ) 的 60% 乙醇摘录被孤立春天。它的结构被分光镜的方法建立。化合物 1 代表在 C-6 拥有一个安息香的酸取代者的 flavonoids 的第一个例子。

Alkaloids from the root barks of Goniothalamus cheliensis

(3S )-2-Oxo-5,12-dimethoxy-3-hydroxy-3-methylbenz[f]indoline (1 ) ，与二已知的碱一起，新 benzoxindole 碱从根被孤立 Goniothalamus cheliensis 胡吠叫。结构被分光镜的证据阐明，并且绝对构型被圆二色性谱决定。

The progress in the chemical constituents of the genus Picrasma during 2007-2017

苦树属植物包括 9个种,主要分布在美洲和亚洲的热带以及亚热带地区.该属某些种的植物作为重要的传统药物资源用于治疗风热感冒、咽喉肿痛、湿热痢疾、恶心晕船、食欲不振、糖尿病、高血压等疾病.2007年,焦伟华等人对苦树属植物的化学成分进行了整理,共综述了 157个化合物.近十年间又有 101个化学成分从苦树属植物中被报道,包括生物碱、苦味素、三萜等.本文对 2007-2017 十年间苦树属植物化学成分的研究进展进行了综述.

Sent2Agri System Based Crop Type Mapping in Yellow River Irrigation Area

Agricultural monitoring is essential for adequate management of food production and distribution.Crop land and crop type classification,using remote sensing time series,form an important tool to capture the agricultural production information.The recently launched Sentinel-2 satellites provide unprecedented monitoring capacities in terms of spatial resolution,swath width,and revisit frequency.The Sentinel-2 for Agriculture(Sen2-Agri)system has been developed to fully exploit those capacities,by providing four relevant earth observation products for agricultural monitoring.Under the Dragon 4 Program,the crop mapping with various satellite images and a specific focus on the Yellow River irrigated agricultural area in the Ningxia Hui Autonomous Region in China was carried out with the Sentinel-2 for Agriculture system(Sent2Agri).9 types of crops were classified and the crop type map in 2017 was produced based on 35 scenes Sentinel 2A/B images.The overall accuracy computed from the error confusion matrix is 88%,which includes the cropped and uncropped types.After the removal of the uncropped area,the overall accuracy for a cropped decrease to 73%.In order to further improve the crop classification accuracy,the training dataset should be further improved and tuned.

An Investigation of Regional Variations in the Biaxial Mechanical Properties of Porcine Mitral Valve

Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.

Viscosity profile prediction of a heavy crude oil during lifting in two deep artesian wells

It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.

Comparative study on identi¯cation of healthy and osteoarthritic articular cartilages by fourier transform infrared imaging and chemometrics methods

Two discriminant methods,partial least squares-discriminant analysis(PLS-DA)and Fisher's discriminant analysis(FDA),were combined with Fourier transform infrared imaging(FTIRI)to differentiate healthy and osteoarthritic articular cartilage in a canine model.Osteoarthritic cartilage had been developed for up to two years after the anterior cruciate ligament(ACL)transection in one knee.Cartilage specimens were sectioned into 10μm thickness for FTIRI.A PLS-DA model was developed after spectral pre-processing.All IR spectra extracted from FTIR images were calculated by PLS-DA with the discriminant accuracy of 90%.Prior to FDA,principal component analysis(PCA)was performed to decompose the IR spectral matrix into informative princi pal component matrices.Based on the different discriminant mechanism,the discriminant accuracy(96%)of PCA-FDA with high convenience was higher than that of PLS-DA.No healthy cartilage sample was mis assigned by these two methods.The above mentioned suggested that both integrated technologies of FTIRI-PLS-DA and,especially,FTIRI-PCA-FDA could become a promising tool for the discrimination of healthy and osteoarthritic cartilage specimen as well as the diagnosis of cartilage lesion at microscopic level.The results of the study would be helpful for better understanding the pathology of osteoarthritics.

High Energy Density Polymeric Nitrogen Nanotubes inside Carbon Nanotubes

Polymeric nitrogen as a new class of high energy density materials has promising applications.We develop a new scheme of crystal structure searching in a confined space using external confining potentials fitted from firstprinciples calculations.As a showcase,this method is employed to systematically explore novel polymeric nitrogen structures confined in single-walled carbon nanotubes.Several quasi-one-dimensional single-bonded polymeric nitrogen structures are realized,two of them are composed of nanotubes instead of chains.These new polymeric nitrogen phases are mechanically stable at ambient pressure and temperature according to phonon calculations and ab initio molecular dynamics simulations.It is revealed that the stabilization of zigzag and armchair chains confined in carbon nanotubes are mostly attributed to the charge transfer from carbon to nitrogen.However,for the novel nitrogen nanotube systems,electrons overlapping in the middle space provide strong Coulomb repulsive forces,which not only induce charge transfer from the middle to the sides but also stabilize the polymeric nitrogen.Our work provides a new strategy for designing novel high-energy-density polymeric nitrogen materials,as well as other new materials with the help of confined space inside porous systems,such as nanotubes,covalent organic frameworks,and zeolites.

Microbial transformation for Region-selective Hydroxylation of Z-Butylidenephthalide by Aspergillus niger CGMCC 3.739

Microbial transformation is a useful tool for structure modification of active natural products.Z-Butylidenephthalide is the main active constituent of Angelica sinensis.In the present work,a pair of new oxidized metabolites,namely(-)(11R)-(Z)-11-hydroxy-butylidenephthalide(1a)and(+)(11S)-(Z)-11-hydroxy-butylidenephthalide(1b),were obtained from microbial transformation for region-selective 11-hydroxylation of Z-butylidenephthalide by Aspergillus niger CGMCC 3.739.Their structures,including absolute configurations,were elucidated by extensive analysis of HR-ESI-MS,NMR spectra,and the modified Mosher’s method.This is the first study on the microbial transformation of Z-butylidenephthalide,and these findings offer a tool for region-selective 11-hydroxylation of Z-butylidenephthalide.

Texture ZnO Thin-Films and their Application as Front Electrode in Solar Cells

In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.

Using Augmented Reality Techniques to Simulate Training and Assistance in Electric Power

In combination with the augmented reality (AR) technology and Hololens device, an electric power work assist system is developed to provide a more realistic and convenient training experience for electric power training. The training effect was improved, and help guidance information was provided in the actual operation of electric power work. Experimental results show that difficulty of electric power work is reduced and the efficiency of actual work is improved.

Study of the multi-physics field-coupled model of the two-stage electrostatic precipitator

The two-stage electrostatic precipitator is widely used to purify oil mist particles.However,there is limited research on the influences of relative humidity,particle deposition characteristics,and the generation of gaseous pollutants.Therefore,this paper established a numerical model of the electrostatic oil mist purifier and applied it to a two-stage electrostatic precipitator.Then the model was used to investigate the corona discharge characteristics under different relative humidity conditions in the charged zone,the particle deposition characteristics,the purification efficiency,the ozone concentration distribution,and the oil vapor concentration distribution in the collection zone.The results indicate that,with a constant temperature,the corona current decreases as relative humidity increase,and there is a quadratic relationship between relative humidity and current.The variation in relative humidity has little impact on the purification efficiency.The maximum ozone concentration occurs near the electrode line,and its concentration is influenced by the discharge current and inlet airflow velocity.The oil vapor concentration reaches its maximum value at the side plates,with a value of 19 ppb,while it reaches the minimum value at the collecting zone electrode plate,with a value of 2 ppb.The temperature is the main factor affecting the volatilization of the oil film,with higher temperatures resulting in higher oil vapor.

Metasurface-enabled augmented reality display: a review

Augmented reality(AR)display,which superimposes virtual images on ambient scene,can visually blend the physical world and the digital world and thus opens a new vista for human–machine interaction.AR display is considered as one of the next-generation display technologies and has been drawing huge attention from both academia and industry.Current AR display systems operate based on a combination of various refractive,reflective,and diffractive optical elements,such as lenses,prisms,mirrors,and gratings.Constrained by the underlying physical mechanisms,these conventional elements only provide limited light-field modulation capability and suffer from issues such as bulky volume and considerable dispersion,resulting in large size,severe chromatic aberration,and narrow field of view of the composed AR display system.Recent years have witnessed the emerging of a new type of optical elements—metasurfaces,which are planar arrays of subwavelength electromagnetic structures that feature an ultracompact footprint and flexible light-field modulation capability,and are widely believed to be an enabling tool for overcoming the limitations faced by current AR displays.Here,we aim to provide a comprehensive review on the recent development of metasurface-enabled AR display technology.We first familiarize readers with the fundamentals of AR display,covering its basic working principle,existing conventional-optics-based solutions,as well as the associated pros and cons.We then introduce the concept of optical metasurfaces,emphasizing typical operating mechanisms,and representative phase modulation methods.We elaborate on three kinds of metasurface devices,namely,metalenses,metacouplers,and metaholograms,which have empowered different forms of AR displays.Their physical principles,device designs,and the performance improvement of the associated AR displays are explained in details.In the end,we discuss the existing challenges of metasurface optics for AR display applications and provide our perspective on future research endeavors.

Aureane-type sesquiterpene tetraketides as a novel class of immunomodulators with interleukin-17A inhibitory activity

Interleukin(IL)-17A,a pro-inflammatory cytokine,is a fundamental function in the onset and advancement of multiple immune diseases.To uncover the primary compounds with IL-17A inhibitory activity,a large-scale screening of the library of traditional Chinese medicine constituents and microbial secondary metabolites was conducted using splenic cells from IL-17A-GFP reporter mice cultured under Th17-priming conditions.Our results indicated that some aureane-type sesquiterpene tetraketides isolated from a wetland mud-derived fungus,Myrothecium gramineum,showed remarkable IL-17A inhibitory activity.Nine new aureane-type sesquiterpene tetraketides,myrogramins A-I(1,4-11),and two known ones(2 and 3)were isolated and identified from the strain.Compounds 1,3,4,10,and 11 exhibited significant IL-17A inhibitory activity.Among them,compound 3,with a high fermentation yield dosedependently inhibited the generation of IL-17A and suppressed glycolysis in splenic cells under Th17-priming conditions.Strikingly,compound 3 suppressed immunopathology in both IL-17A-mediated animal models of experimental autoimmune encephalomyelitis and pulmonary hypertension.Our results revealed that aureane-type sesquiterpene tetraketides are a novel class of immunomodulators with IL-17A inhibitory activity,and hold great promise applications in treating IL-17A-mediated immune diseases.

Dynamics of buoyancy-driven microflow in a narrow annular space

This paper aims to investigate the dynamics of buoyancy-driven microflow in a narrow annular space inside a liquid floated gyroscope(LFG). Several theoretical models with a non-uniform thermal boundary for fluid flow in annular channels are given to analyze the effects of various parameters, such as the clearance size h, roughness height re, and rough density ε, on the flow and temperature profiles as well as on the fluid-drag torque. In the narrow annular regime, the relationship between the temperature and the angular displacement of the outer wall is defined as a cosine function, and the surface roughness of the inner wall is structured as a series of surface protrusions with a circular shape. With the increase of clearance size h, the flow velocity gradually increases to a stable level, and the drag torque increases initially and then decreases to a stable level. Furthermore, the increase of roughness height re and roughness density ε intensifies the frictional effect of fluid on the inner-wall surface. However, these two parameters have no significant effect on the flow velocity. This study can provide theoretical references for precision manufacturing and precision improvement of gyro instruments.

Ecological Assessment of Oxygen Balance:A Case Study of China’s Natural Oxygen Bars

Ecological assessment plays a vital role in sustainable development of the environment,and thus exploration of specific and integrated ecological assessment methods has become a critical task.In this study,based on the concept of oxygen balance and by accommodating both natural factors and socioeconomic elements,we establish an oxygen(O_(2))balance index(OBI),i.e.,the ratio of the O_(2)production from the ecosystem to the O_(2)consumption by human behavior,based on the net primary productivity(NPP),fuel consumption,gross domestic production(GDP),population data,and so on.The results show that the spatial distributions of OBI in China are intimately correlated to the regional vegetation and socioeconomic development.The estimated OBI values are then validated by statistical data from 27 counties in China,and it is found that the OBI reflects the ecological environment status well.Moreover,the average OBI values derived from 190 natural oxygen bars in China reveal extreme imbalance between O_(2)production and consumption in highly developed regions,especially in the cities,in contrast to good O_(2)balance in areas with high-quality ecological status and less industrialization.The findings from this study have quantitatively captured the regional ecological quality,providing guidance for sustainable natural and socioeconomic developments in local areas of China.

Fluid-structure interaction simulation of pathological mitral valve dynamics in a coupled mitral valve-left ventricle model

Background Understanding the interaction between the mitral valve(MV)and the left ventricle(LV)is very important in assessing cardiac pump function,especially when the MV is dysfunctional.Such dysfunction is a major medical problem owing to the essential role of the MV in cardiac pump function.Computational modelling can provide new approaches to gain insight into the functions of the MV and LV.Methods In this study,a previously developed LV-MV model was used to study cardiac dynamics of MV leaflets under normal and pathological conditions,including hypertrophic cardiomyopathy(HOCM)and calcification of the valve.The coupled LV-MV model was implemented using a hybrid immersed boundary/finite element method to enable assessment of MV haemodynamic performance.Constitutive parameters of the HOCM and calcified valves were inversely determined from published experimental data.The LV compensation mechanism was further studied in the case of the calcified MV.Results Our results showed that MV dynamics and LV pump function could be greatly affected by MV pathology.For example,the HOCM case showed bulged MV leaflets at the systole owing to low stiffness,and the calcified MV was associated with impaired diastolic filling and much-reduced stroke volume.We further demonstrated that either increasing the LV filling pressure or increasing myocardial contractility could enable a calcified valve to achieve near-normal pump function.Conclusion The modelling approach developed in this study may deepen our understanding of the interactions between the MV and the LV and help in risk stratification of heart valve disease and in silico treatment planning by exploring intrinsic compensation mechanisms.