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AB002.Cone rescue in retinitis pigmentosa by the treatment of Lycium barbarum(Random Clinical Trial)
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作者 henry chan Hang-I Lam +9 位作者 Kwok-Fai So Raymond Chuen-Chung chang Shiu-Ming Lai Chi-Wai Do Iris F.F.Benzie Chin-Pan Leung Kai-Yip Choi Man-Pan Chin Zhe-Chuang Li Wing-Yan Yu 《Annals of Eye Science》 2017年第1期356-356,共1页
Retinitis pigmentosa(RP)is a group of heredofamilial retinal diseases which is characterized by night blindness and progressive visual field loss.This study aims to study the treatment effect of Lycium barbarum(LB)on ... Retinitis pigmentosa(RP)is a group of heredofamilial retinal diseases which is characterized by night blindness and progressive visual field loss.This study aims to study the treatment effect of Lycium barbarum(LB)on retinal functions and structure of RP patients.The study is a double-masked randomized controlled trial.RP subjects received scheduled eye examination including visual acuity(VA),Humphrey field analysis(HFA),ganzfeld flash electroretinogram(ffERG)and optical coherence tomography(OCT).The suitable subjects were randomly allocated to either LB-treatment or placebo groups with the supply of LB or placebo for 12 months.There were total 41 RP subjects(22 in LB group and 19 in placebo group)completed the 12 months intervention.The compliance rates for LB and placebo groups were 89.8%±12.5%and 85.3%±7.7%respectively.As compared with placebo group,there were no deteriorations of both high and low contrast VA in LB group(P<0.01).In addition,certain improvements of scotopic rod response and photopic cone response of ffERG were obtained in LB group(P<0.05).In the OCT measurement,an obvious thinning of macular thickness was observed in placebo group but not found in LB group(P<0.05).However,there were no changes found in the sensitivity of central visual field between two groups.Our results confirm that the 12-month LB treatment for RP patients had neuroprotective effect on retina and is believed to delay or minimize the deterioration of visual function in RP. 展开更多
关键词 Retinitis pigmentosa(RP) Lycium barbarum(LB) NEUROPROTECTION CONE RETINA
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Machine learning enabled autonomous microstructural characterization in 3D samples 被引量:7
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作者 henry chan Mathew Cherukara +2 位作者 Troy D.Loeffler Badri Narayanan Subramanian K.R.S.Sankaranarayanan 《npj Computational Materials》 SCIE EI CSCD 2020年第1期1654-1662,共9页
We introduce an unsupervised machine learning(ML)based technique for the identification and characterization of microstructures in three-dimensional(3D)samples obtained from molecular dynamics simulations,particle tra... We introduce an unsupervised machine learning(ML)based technique for the identification and characterization of microstructures in three-dimensional(3D)samples obtained from molecular dynamics simulations,particle tracking data,or experiments.Our technique combines topology classification,image processing,and clustering algorithms,and can handle a wide range of microstructure types including grains in polycrystalline materials,voids in porous systems,and structures from self/directed assembly in soft-matter complex solutions.Our technique does not require a priori microstructure description of the target system and is insensitive to disorder such as extended defects in polycrystals arising from line and plane defects.We demonstrate quantitively that our technique provides unbiased microstructural information such as precise quantification of grains and their size distributions in 3D polycrystalline samples,characterizes features such as voids and porosity in 3D polymeric samples and micellar size distribution in 3D complex fluids.To demonstrate the efficacy of our ML approach,we benchmark it against a diverse set of synthetic data samples representing nanocrystalline metals,polymers and complex fluids as well as experimentally published characterization data.Our technique is computationally efficient and provides a way to quickly identify,track,and quantify complex microstructural features that impact the observed material behavior. 展开更多
关键词 MICROSTRUCTURE POLYCRYSTALLINE POROSITY
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AutoPhaseNN:unsupervised physics-aware deep learning of 3D nanoscale Bragg coherent diffraction imaging 被引量:6
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作者 Yudong Yao henry chan +3 位作者 Subramanian Sankaranarayanan Prasanna Balaprakash Ross J.Harder Mathew J.Cherukara 《npj Computational Materials》 SCIE EI CSCD 2022年第1期1146-1153,共8页
The problem of phase retrieval underlies various imaging methods from astronomy to nanoscale imaging.Traditional phase retrieval methods are iterative and are therefore computationally expensive.Deep learning(DL)model... The problem of phase retrieval underlies various imaging methods from astronomy to nanoscale imaging.Traditional phase retrieval methods are iterative and are therefore computationally expensive.Deep learning(DL)models have been developed to either provide learned priors or completely replace phase retrieval.However,such models require vast amounts of labeled data,which can only be obtained through simulation or performing computationally prohibitive phase retrieval on experimental datasets.Using 3D X-ray Bragg coherent diffraction imaging(BCDI)as a representative technique,we demonstrate AutoPhaseNN,a DL-based approach which learns to solve the phase problem without labeled data.By incorporating the imaging physics into the DL model during training,AutoPhaseNN learns to invert 3D BCDI data in a single shot without ever being shown real space images.Once trained,AutoPhaseNN can be effectively used in the 3D BCDI data inversion about 100×faster than iterative phase retrieval methods while providing comparable image quality. 展开更多
关键词 COHERENT ITERATIVE replace
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CEGANN: Crystal Edge Graph Attention Neural Network for multiscale classification of materials environment 被引量:2
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作者 Suvo Banik Debdas Dhabal +4 位作者 henry chan Sukriti Manna Mathew Cherukara Valeria Molinero Subramanian K.R.S.Sankaranarayanan 《npj Computational Materials》 SCIE EI CSCD 2023年第1期2106-2117,共12页
We introduce Crystal Edge Graph Attention Neural Network (CEGANN) workflow that uses graph attention-based architecture tolearn unique feature representations and perform classification of materials across multiple sc... We introduce Crystal Edge Graph Attention Neural Network (CEGANN) workflow that uses graph attention-based architecture tolearn unique feature representations and perform classification of materials across multiple scales (from atomic to mesoscale) anddiverse classes ranging from metals, oxides, non-metals to hierarchical materials such as zeolites and semi-ordered mesophases.CEGANN can classify based on a global, structure-level representation such as space group and dimensionality (e.g., bulk, 2D,clusters, etc.). Using representative materials such as polycrystals and zeolites, we demonstrate its transferability in performing localatom-level classification tasks, such as grain boundary identification and other heterointerfaces. CEGANN classifies in (thermal)noisy dynamical environments as demonstrated for representative zeolite nucleation and growth from an amorphous mixture.Finally, we use CEGANN to classify multicomponent systems with thermal noise and compositional diversity. Overall, our approachis material agnostic and allows for multiscale feature classification ranging from atomic-scale crystals to heterointerfaces tomicroscale grain boundaries. 展开更多
关键词 CRYSTAL classify ZEOLITE
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Opportunities for retrieval and tool augmented large language models in scientific facilities 被引量:3
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作者 Michael H.Prince henry chan +7 位作者 Aikaterini Vriza Tao Zhou Varuni K.Sastry Yanqi Luo Matthew T.Dearing Ross J.Harder Rama K.Vasudevan Mathew J.Cherukara 《npj Computational Materials》 CSCD 2024年第1期588-595,共8页
Upgrades to advanced scientific user facilities such as next-generation x-ray light sources,nanoscience centers,and neutron facilities are revolutionizing our understanding of materials across the spectrum of the phys... Upgrades to advanced scientific user facilities such as next-generation x-ray light sources,nanoscience centers,and neutron facilities are revolutionizing our understanding of materials across the spectrum of the physical sciences,from life sciences to microelectronics.However,these facility and instrument upgrades come with a significant increase in complexity.Driven by more exacting scientific needs,instruments and experiments become more intricate each year.This increased operational complexity makes it ever more challenging for domain scientists to design experiments that effectively leverage the capabilities of and operate on these advanced instruments.Large language models(LLMs)can perform complex information retrieval,assist in knowledge-intensive tasks across applications,and provide guidance on tool usage.Using x-ray light sources,leadership computing,and nanoscience centers as representative examples,we describe preliminary experiments with a Context-Aware Language Model for Science(CALMS)to assist scientists with instrument operations and complex experimentation.With the ability to retrieve relevant information from facility documentation,CALMS can answer simple questions on scientific capabilities and other operational procedures.With the ability to interface with software tools and experimental hardware,CALMS can conversationally operate scientific instruments.By making information more accessible and acting on user needs,LLMs could expand and diversify scientific facilities’users and accelerate scientific output. 展开更多
关键词 instrument INSTRUMENTS facilities
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A Continuous Action Space Tree search for INverse desiGn (CASTING) framework for materials discovery 被引量:1
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作者 Suvo Banik Troy Loefller +5 位作者 Sukriti Manna henry chan Srilok Srinivasan Pierre Darancet Alexander Hexemer Subramanian K.R.S.Sankaranarayanan 《npj Computational Materials》 SCIE EI CSCD 2023年第1期500-515,共16页
Material properties share an intrinsic relationship with their structural attributes,making inverse design approaches crucial for discovering new materials with desired functionalities.Reinforcement Learning(RL)approa... Material properties share an intrinsic relationship with their structural attributes,making inverse design approaches crucial for discovering new materials with desired functionalities.Reinforcement Learning(RL)approaches are emerging as powerful inverse design tools,often functioning in discrete action spaces.This constrains their application in materials design problems,which involve continuous search spaces.Here,we introduce an RL-based framework CASTING(Continuous Action Space Tree Search for inverse design),that employs a decision tree-based Monte Carlo Tree Search(MCTS)algorithm with continuous space adaptation through modified policies and sampling.Using representative examples like Silver(Ag)for metals,Carbon(C)for covalent systems,and multicomponent systems such as graphane,boron nitride,and complex correlated oxides,we showcase its accuracy,convergence speed,and scalability in materials discovery and design.Furthermore,with the inverse design of super-hard Carbon phases,we demonstrate CASTING’s utility in discovering metastable phases tailored to user-defined target properties and preferences. 展开更多
关键词 Action FRAMEWORK TREE
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Multi-reward reinforcement learning based development of inter-atomic potential models for silica
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作者 Aditya Koneru henry chan +5 位作者 Sukriti Manna Troy D.Loeffler Debdas Dhabal Andressa A.Bertolazzo Valeria Molinero Subramanian K.R.S.Sankaranarayanan 《npj Computational Materials》 SCIE EI CSCD 2023年第1期1059-1071,共13页
Silica is an abundant and technologically attractive material.Due to the structural complexities of silica polymorphs coupled with subtle differences in Si–O bonding characteristics,the development of accurate models... Silica is an abundant and technologically attractive material.Due to the structural complexities of silica polymorphs coupled with subtle differences in Si–O bonding characteristics,the development of accurate models to predict the structure,energetics and properties of silica polymorphs remain challenging.Current models for silica range from computationally efficient Buckingham formalisms(BKS,CHIK,Soules)to reactive(ReaxFF)and more recent machine-learned potentials that are flexible but computationally costly.Here,we introduce an improved formalism and parameterization of BKS model via a multireward reinforcement learning(RL)using an experimental training dataset.Our model concurrently captures the structure,energetics,density,equation of state,and elastic constants of quartz(equilibrium)as well as 20 other metastable silica polymorphs.We also assess its ability in capturing amorphous properties and highlight the limitations of the BKS-type functional forms in simultaneously capturing crystal and amorphous properties.We demonstrate ways to improve model flexibility and introduce a flexible formalism,machine-learned ML-BKS,that outperforms existing empirical models and is on-par with the recently developed 50 to 100 times more expensive Gaussian approximation potential(GAP)in capturing the experimental structure and properties of silica polymorphs and amorphous silica. 展开更多
关键词 AMORPHOUS potential ATTRACTIVE
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