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Prostate cancer identification: quantitative analysis of T2-weighted MR images based on a back propagation artificial neural network model

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Science China(Life Sciences) 2015年第7期58卷 666-673页

作者： ZHAO Kai WANG ChengYan HU Juan YANG XueDong WANG He LI FeiYu ZHANG XiaoDong ZHANG Jue WANG XiaoYing Department of Radiology Peking University First Hospital academy for advanced interdisciplinary studies Peking University

Computer-aided diagnosis(CAD) systems have been proposed to assist radiologists in making diagnostic decisions by providing helpful information. As one of the most important sequences in prostate magnetic resonance imaging(MRI), image features from T2-weighted images(T2WI) were extracted and evaluated for the diagnostic performances by using CAD. We extracted 12 quantitative image features from prostate T2-weighted MR images. The importance of each feature in cancer identification was compared in the peripheral zone(PZ) and central gland(CG), respectively. The performance of the computer-aided diagnosis system supported by an artificial neural network was tested. With computer-aided analysis of T2-weighted images, many characteristic features with different diagnostic capabilities can be extracted. We discovered most of the features(10/12) had significant difference(P<0.01) between PCa and non-PCa in the PZ, while only five features(sum average, minimum value, standard deviation, 10 th percentile, and entropy) had significant difference in CG. CAD prediction by features from T2 w images can reach high accuracy and specificity while maintaining acceptable sensitivity. The outcome is convictive and helpful in medical diagnosis.

关键词： prostate cancer magnetic resonance imaging T2WI diagnosis computer-assisted

Enhanced Anti-corrosion Ability and Biocompatibility of PLGA Coatings on MgZnYNd Alloy by BTSE-APTES Pre-treatment for Cardiovascular Stent

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Journal of Materials Science & Technology 2016年第9期32卷 845-857页

作者： Jing Liu Tingfei Xi Center for Biomedical Materials and Tissue Engineering Academy for Advanced Interdisciplinary Studies Peking University Shenzhen Institute Peking University

Bioabsorbable magnesium alloys are widely studied for various implant applications, as they reduce the risks such as severe inflammatory response existing in permanent metallic implants. However, the over-fast corrosion rate of magnesium alloy is usually an obstacle in biomedical applications. Here we report a simple two-step reaction to introduce anticorrosive silane pre-treatment on MgZnYNd alloys before coating with poly （glycolide-co-lactide）（PLGA）. The first step is to immerse the NaOH-activated MgZnYNd with bistriethoxysilylethane （BTSE） to form a cross-linked silane coating layer with enhanced corrosion resistance; the second step involves immobilizing amine functional groups for forming hydrogen bond with outer PLGA coating by treating the BTSE-modified MgZnYNd with 3-amino-propyltrimethoxysilane （APTES）. We characterized the BTSE-APTES pre-treated PLGA coating on MgZnYNd by scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FF-IR）, X-ray photoelectron spectroscopy （XPS）, static contact angle and Acid Orange 7 measurement. Nano-scratch test was to verify that the scratch resistance of the PLGA coating with BTSE-APTES pre-treatment was superior to direct PLGA coating. Stan-dard electrochemical measurements along with the long-term immersion results indicated that the BTSE- APTES pre-treatment rendered better in vitro degradation behavior. Cell adhesion and cell viability tests with both vascular smooth muscle cells （VSMC） and human umbilical vein endothelial cells （EA. hy926） demonstrated that BTSE-APTES pre-treated MgZnYNd substrate had significantly more beneficial effects. The favorable anti-corrosion behavior and biocompatibility of BTSE-APTES pre-treated PLGA coatings on MgZnYNd alloy suggest that the novel two-step silanization procedure may have the great potential to enhance the performance of the magnesium-based biomaterials and provide a valid solution for the conversion modification of cardiovascular implants, taking the

关键词： Cardiovascular stent SilanizationAnti-corrosion Cytocompatibility MgZnYNd alloy

Improved atom number with a dual color magneto-optical trap

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Chinese Physics B 2012年第4期21卷 10-13页

作者：曹强罗鑫宇高奎意王晓锐陈东敏王如泉 Institute of Physics Chinese Academy of SciencesBeijing 100190China academy for advanced interdisciplinary studies Peking UniversityBeijing 100871China

We demonstrate a novel dual color magneto optical trap （MOT）, which uses two sets of overlapping laser beams to cool and trap SrRb atoms. Tile volume of cold cloud in the dual color MOT is strongly dependent on the frequency difference of the laser beams and can be significantly larger than that in the normal MOT with single frequency MOT beams. Our experiment shows that the dual color MOT has the same loading rate as the normal MOT, but much longer loading time, leading to threefold increase in the number of trapped atoms. This indicates that the larger number is caused by reduced light induced loss. The dual color MOT is very useful in experiments where both high vacuum level and large atom mmlbcr are required, such as single chamber quantum memory and Bose-Einstein condensation （BEC） experiments. Compared to the popular dark spontaneous-force optical trap （dark SPOT） technique, our approach is technically simpler and more suitable to low power laser systems.

关键词： inagneto optical trap

Phase field simulation of dendrite growth in gas atomized binary Al-Ni droplets

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Particuology 2020年第3期18卷 43-52页

作者： Yuntao Cai Pengjun Fang Xinggang Li Yi Xu School of Materials Science&Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of advanced Materials Technology Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China sustech academy for advanced interdisciplinary studies Southern University of Science and TechnologyShenzhen 518055China

Catalytic powders with fine microstructures can be produced from a rapidly solidified gas atomized Al-Ni *** solidification microstructure of the droplets is closely linked with heat flow ***,the heat transfer conditions between the gas and droplet are essential to microstructural *** this study,a phase field model for simulating single and multiple dendrite growth in a binary Al-Ni alloy was constructed and the microstructural evolutions occurring during a gas atomization process were *** variations in the heat transfer coefficient and the boundary heat flux were taken into *** results revealed that the heat transfer coefficient of the atomized droplet in flight is correlated with the droplet size and the relative velocity between the droplet and the atomizing *** the simulation,the competition between boundary heat flux extraction and latent heat release from phase transition causes a recalescence process in thermal history,thereby affecting the gradient temperature distribution and,consequently,the dendrite *** growth under the effects of the heat transfer coefficient is restrained continuously because of the decreasing amount of *** computational results confirmed the fine homogeneous microstructure and low microsegregation levels of gas atomized powders.

关键词： Numerical simulation Dendrite morphology Solidification Gas atomization

A 3D hierarchical electrocatalyst:Core–shell Cu@Cu(OH)_(2)nanorods/MOF octahedra supported on N-doped carbon for oxygen evolution reaction

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Nano Research 2023年第5期16卷 8012-8017页

作者： Xinran Li Yipei Li Changli Wang Huaiguo Xue Huan Pang Qiang Xu School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225009China Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(SKLPM) SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory(SKAEM-JIL)Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of GuangdongDepartment of ChemistryDepartment of Materials Science and Engineering and SUSTech Academy for Advanced Interdisciplinary StudiesSouthern University of Science and Technology(SUSTech)Shenzhen 518055China

Cu-based materials are seldom reported as oxygen evolution reaction(OER)electrocatalysts due to their inherent electron orbital configuration,which makes them difficult to adsorb oxygen-intermediates during *** engineering the hierarchical architectures and the electronic structures can improve the performance of Cu-based OER catalysts,such as constructing multilevel morphology,inducing the porous materials,improving the Cu valence,building heterostructures,doping heteroatoms,*** this work,copper-1,3,5-benzenetricarboxylate(HKUST-1)octahedra in-situ grow on the Cu nanorod(NR)-supported N-doped carbon microplates,meanwhile an active layer of Cu(OH)_(2)forms on the surface of the original conductive Cu *** octahedral HKUST-1,serving as a spacer between the microplates,greatly improves the porosity and increases the available active sites,facilitating the mass transport and electron transfer,thus resulting in greatly enhanced OER performance.

关键词： core–shell nanorod Cu@Cu(OH)_(2) metal–organic framework oxygen evolution reaction

A simple magnetic force-based cell patterning method using soft lithography

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Science China(Life Sciences) 2015年第4期58卷 400-402页

作者： LI ShanShan LIU XiangQi CHAU Alicia PENG XiaoLing GUIDO Isabella WANG LiLi GE ZiGang XIONG ChunYang academy for advanced interdisciplinary studies Peking University College of Engineering Peking University

Dear Editor,Cell patterning is gaining more and more attention regarding a wide range of applications including cell biology, tissue engineering, and biosensor technology, to name a few. Magnetic force provides a promising tool to pattern cells because it is of excellent biocompatibility, tunable and reversible, and can be employed flexibly in or out of the cell culture system [1]. While extensive studies [2-5] contribute valuable approaches for positioning cells with high resolution, costly and time-consuming fabrication procedures, such as electrodeposition and electrical discharge, still limit the application of these techniques.

关键词：细胞生物学图案磁力软光刻基础生物传感器生物相容性组织工程

Development status of high power fiber lasers and their coherent beam combination

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Science China(Information Sciences) 2019年第4期62卷 56-87页

作者： Zejin LIU Xiaoxi JIN Rongtao SU Pengfei MA Pu ZHOU College of advanced interdisciplinary studies National University of Defense Technology

High-power fiber laser has been emerged great potential in a wide range of applications and becomes a robust candidate for high energy solid state laser system. To further increase the output brightness of single-channel fiber laser, high-brightness pump sources and high-power-handling passive components should be fabricated and utilized in the fiber laser systems, in addition to the advanced techniques for multiple nonlinear effects managements. The state-of-the-art high power fiber lasers are reviewed, in terms of narrow-linewidth fiber lasers, broadband fiber lasers and fiber lasers at 2 μm. Coherent beam combining is a promising technique to obtain higher output power while maintaining excellent beam quality simultaneously,which breaks through the bottlenecks of single-channel fiber laser. Based on a series of key techniques for coherent beam combining, high-power coherent beam combining of fiber lasers could be enabled with high combining efficiency. In this paper, we review the progress of high-power fiber lasers and their coherent beam combining in the recent decade, particularly the relevant work in our group. The future prospects of fiber lasers and coherent beam combining technique are also discussed.

关键词： fiber lasers and amplifiers nonlinear effects and mode instability coherent beam combining passive components 2 μm fiber lasers

Intrinsic transverse relaxation mechanisms of polarized alkali atoms enclosed in radio-frequency magnetometer cell

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Chinese Physics B 2019年第9期28卷 385-390页

作者： Yang-Ying Fu Jie Yuan College of advanced interdisciplinary studies National University of Defense Technology

The intrinsic transverse relaxation mechanisms of polarized alkali atoms enclosed in the radio-frequency magnetometer cell are *** intrinsic transverse relaxation rate of cesium atoms as a function of cell temperature is *** absorption of alkali atoms by the glass wall and the reservoir effect are the main error factors which contribute to the disagreements between theory and experiments.A modified relaxation model is presented, in which both the absorption of alkali atoms by the glass wall and the reservoir effect are *** study provides a more accurate description of the intrinsic transverse relaxation mechanisms of polarized alkali atoms, and enlightens the optimization of the cell design.

关键词： intrinsic transverse relaxation modified relaxation model absorption of alkali atoms reservoir effect

Novel transit-time oscillator(TTO) combining advantages of radial-line and axial TTO

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Chinese Physics B 2019年第8期28卷 220-224页

作者： Wei-Li Xu Jun-Tao He Jun-Pu Ling Li-Li Song Bing-Fang Deng Ouzhixiong Dai Xing-Jun Ge College of advanced interdisciplinary studies National University of Defense Technology

A novel transit-time oscillator(TTO)is proposed in this *** axial cathode which has been widely used in high power microwave(HPM)source and an extractor with radial feature are *** this way,the inherent advantages of axial and radial TTO,both of which can be utilized as high-quality intense relativistic electron beam(IREB),can be generated and the power capacity is also *** working mode isπ/2 mode of TM01 based on small-signal theory,and under the same energy storage,the maximum electric field in extractor decreases 16.3%.Besides,by utilizing the natural bending of the solenoid,this TTO saves over 60%of the length required by the uniform magnetic field,and consequently reduces the energy consumed by *** PIC simulation shows that by using 1.0-T decreasing magnetic field generated by the shorter solenoid,3.37-GW microwave at 12.43 GHz is generated with 620-kV and 13.27-kA input,and the overall conversion efficiency is 41%.

关键词： axial TTO radial-feature extractor larger power capacity shorter uniform magnetic field