Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected ...Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world’s largest grape gene banks,the grape germplasm collection of the United States Department of Agriculture.We find that phenological events throughout the growing season are correlated,and quantify the marked difference in size between table and wine grapes.By pairing publicly available historical phenotype data with genome-wide polymorphism data,we identify large effect loci controlling traits that have been targeted during domestication and breeding,including hermaphroditism,lighter skin pigmentation and muscat aroma.Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited,whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions.We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries.Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes.展开更多
目的从微生物角度探究重度低龄儿童龋(severe early childhood caries,S⁃ECC)患儿一次完成龋病治疗前、治疗后3个月内菌斑微生物群落构成和多样性的变化及治疗对于远期无龋状态维持的作用。方法S⁃ECC患儿在全身麻醉下一次完成龋病治疗,...目的从微生物角度探究重度低龄儿童龋(severe early childhood caries,S⁃ECC)患儿一次完成龋病治疗前、治疗后3个月内菌斑微生物群落构成和多样性的变化及治疗对于远期无龋状态维持的作用。方法S⁃ECC患儿在全身麻醉下一次完成龋病治疗,采集治疗前(C)、术后7 d(C⁃7D)、1个月(C⁃1M)、3个月(C⁃3M)无龋牙面集合菌斑,并纳入无龋儿童(CF)为对照组,分析治疗前后菌斑微生物群落短期内的动态改建过程。结果S⁃ECC组和CF组菌斑群落组成高度相似;组间α多样性指数差异无统计学意义(P>0.05);从相对丰度值分析,纤毛菌属、聚集杆菌属等在治疗后较术前下降(P<0.05),C⁃7D组血链球菌较C组上升并在3个月内逐渐下降;治疗前韦荣菌属、放线菌属、拟普雷沃菌属、二氧化碳嗜纤维菌属、变异链球菌在C组和CF组间存在显著差异(P<0.05),其中变异链球菌经治疗后的C⁃7D、C⁃1M组与CF组未存在显著差异,而C⁃3M组较CF组出现上升(P<0.01)。结论S⁃ECC患儿在接受治疗后菌群结构的迅速改变,并在治疗后1~3个月逐渐开始建立新的无龋状态下的平衡。核心微生物群的存在使得菌斑群落保持稳定,韦荣菌属、拟普雷沃菌属、变异链球菌等具备作为龋病菌斑微生物标记物潜能。展开更多
This review paper aims to summarize cardiac CT blooming artifacts,how they present clinically and what their root causes and potential solutions are.A literature survey was performed covering any publications with a s...This review paper aims to summarize cardiac CT blooming artifacts,how they present clinically and what their root causes and potential solutions are.A literature survey was performed covering any publications with a specific interest in calcium blooming and stent blooming in cardiac CT.The claims from literature are compared and interpreted,aiming at narrowing down the root causes and most promising solutions for blooming artifacts.More than 30 journal publications were identified with specific relevance to blooming artifacts.The main reported causes of blooming artifacts are the partial volume effect,motion artifacts and beam hardening.The proposed solutions are classified as high-resolution CT hardware,high-resolution CT reconstruction,subtraction techniques and post-processing techniques,with a special emphasis on deep learning(DL)techniques.The partial volume effect is the leading cause of blooming artifacts.The partial volume effect can be minimized by increasing the CT spatial resolution through higherresolution CT hardware or advanced high-resolution CT reconstruction.In addition,DL techniques have shown great promise to correct for blooming artifacts.A combination of these techniques could avoid repeat scans for subtraction techniques.展开更多
There are a great variety of commercial nickel alloys mainly because nickel is able to dissolve a large amount of alloying elements while maintaining a single ductile austenitic phase. Nickel alloys are generally desi...There are a great variety of commercial nickel alloys mainly because nickel is able to dissolve a large amount of alloying elements while maintaining a single ductile austenitic phase. Nickel alloys are generally designed for and used in highly aggressive environments, for example, those where stainless steels may experience pitting corrosion or environmentally assisted cracking. While nickel alloys are generally resistant to pitting corrosion in chloride-containing environments, they may be prone to crevice corrosion attack. Addition of chromium, molybdenum and tungsten increases the localized corrosion resistance of nickel alloys. This review on the resistance to localized corrosion of nickel alloys includes specific environments such as those present in oil and gas upstream operations, in the chemical process industry and in seawater service.展开更多
Composites of mesoporous carbon（CMK-3） and Co3 O4 nanosheets grown on nickel foam were successfully synthesized by a simple route. A bare Co3 O4 film was synthesized for comparison. With the addition of CMK-3, the C...Composites of mesoporous carbon（CMK-3） and Co3 O4 nanosheets grown on nickel foam were successfully synthesized by a simple route. A bare Co3 O4 film was synthesized for comparison. With the addition of CMK-3, the Co3 O4 nanoparticles self-organize and agglomerate into nanosheets, showing a significant influence by CMK-3 on the morphology. The CMK-3/Co3 O4 exhibits an optimal specific capacitance of 1131.3 Fg^（-1） in 3 mol L-1 KOH aqueous electrolyte at 0.5 Ag-1, and a retention ratio of 91% over3000 cycles, both being much higher than that achieved from the bare Co3 O4 film（727 Fg^（-1） of specific capacitance, and 82% capacitance retention ratio）, indicating that the CMK-3/Co3 O4 nanosheets are very promising as electrode materials for supercapacitor applications.展开更多
BACKGROUND Liver surgery has traditionally been characterized by the complexity of its procedures and potentially high rates of morbidity and mortality in inexperienced hands.The robotic approach has gradually been in...BACKGROUND Liver surgery has traditionally been characterized by the complexity of its procedures and potentially high rates of morbidity and mortality in inexperienced hands.The robotic approach has gradually been introduced in liver surgery and has increased notably in recent years.However,few centers currently perform robotic liver surgery and experiences in robot-assisted surgical procedures continue to be limited compared to the laparoscopic approach.AIM To analyze the outcomes and feasibility of an initial robotic liver program implemented in an experienced laparoscopic hepatobiliary center.METHODS A total of forty consecutive patients underwent robotic liver resection(da Vinci Xi,intuitive.com,United States)between June 2019 and January 2021.Patients were prospectively followed and retrospectively reviewed.Clinicopathological characteristics and perioperative and short-term outcomes were analyzed.Data are expressed as mean and standard deviation.The study was approved by the Institutional Review Board.RESULTS The mean age of patients was 59.55 years,of which 18(45%)were female.The mean body mass index was 29.41 kg/m^(2).Nine patients(22.5%)were cirrhotic.Patients were divided by type of resection as follows:Ten segmentectomies,three wedge resections,ten left lateral sectionectomies,six bisegmentectomies(two VVI bisegmentectomies and four IVb-V bisegmentectomies),two right anterior sectionectomies,five left hepatectomies and two right hepatectomies.Malignant lesions occurred in twenty-nine(72.5%)of the patients.The mean operative time was 258.11 min and two patients were transfused intraoperatively(5%).Inflow occlusion was used in thirty cases(75%)and the mean total clamping time was 32.62 min.There was a single conversion due to uncontrollable hemorrhage.Major postoperative complications(Clavien–Dindo>Ⅲb)occurred in three patients(7.5%)and mortality in one(2.5%).No patient required readmission to the hospital.The mean hospital stay was 5.6 d.CONCLUSION Although robotic hepatectomy is a safe and feasible procedure with favorable short-term outcomes,it involves a demanding learning curve that requires a high level of training,skill and dexterity.展开更多
Deep learning(DL)has shown unprecedented performance for many image analysis and image enhancement tasks.Yet,solving large-scale inverse problems like tomographic reconstruction remains challenging for DL.These proble...Deep learning(DL)has shown unprecedented performance for many image analysis and image enhancement tasks.Yet,solving large-scale inverse problems like tomographic reconstruction remains challenging for DL.These problems involve non-local and space-variant integral transforms between the input and output domains,for which no efficient neural network models are readily available.A prior attempt to solve tomographic reconstruction problems with supervised learning relied on a brute-force fully connected network and only allowed reconstruction with a 128^(4)system matrix size.This cannot practically scale to realistic data sizes such as 512^(4)and 512^(6)for three-dimensional datasets.Here we present a novel framework to solve such problems with DL by casting the original problem as a continuum of intermediate representations between the input and output domains.The original problem is broken down into a sequence of simpler transformations that can be well mapped onto an efficient hierarchical network architecture,with exponentially fewer parameters than a fully connected network would need.We applied the approach to computed tomography(CT)image reconstruction for a 5124 system matrix size.This work introduces a new kind of data-driven DL solver for full-size CT reconstruction without relying on the structure of direct(analytical)or iterative(numerical)inversion techniques.This work presents a feasibility demonstration of full-scale learnt reconstruction,whereas more developments will be needed to demonstrate superiority relative to traditional reconstruction approaches.The proposed approach is also extendable to other imaging problems such as emission and magnetic resonance reconstruction.More broadly,hierarchical DL opens the door to a new class of solvers for general inverse problems,which could potentially lead to improved signal-to-noise ratio,spatial resolution and computational efficiency in various areas.展开更多
This paper focuses on the state space modeling approach and output torques prediction of torsional vibrations for variable speed wind turbines. The multi-body system model under study is mainly comprised of a wind tur...This paper focuses on the state space modeling approach and output torques prediction of torsional vibrations for variable speed wind turbines. The multi-body system model under study is mainly comprised of a wind turbine, a three stage planetary gear box and an induction generator. The masses-springs approach of shaft system differential equations is developed from Newton＇s law and Lagrange formulas. For an easy comprehension for electrical engineers and tutorial purpose, an electrical equivalent circuit of the system is proposed by using mechanical and electrical components similarities. Extensive numerical simulations are performed to investigate system mechanical resonances and impacts of damping factors on the system dynamic and stability.展开更多
Nanodielectric composites have been developed in recent years attempting to improve the dielectric properties such as dielectric constant, dielectric strength and voltage endurance. Among various investigations, nanop...Nanodielectric composites have been developed in recent years attempting to improve the dielectric properties such as dielectric constant, dielectric strength and voltage endurance. Among various investigations, nanoparticle dispersion was particularly emphasized in this work. General Electric Global Research Center in Niskayuna NY USA has investigated various nanoparticles, nanocomposites and nanocomposite synthesis methods intending to understand particle dispersion and their impact on the nanocomposite dielectric properties. The breakdown strength and microstructures of the nanocomposites containing different particles were studied for projects related to capacitor and electrical insulation technologies. The nanocomposite synthesis methods either employed commerical nanoparticles or utilized nanoparticles that were self-assembled (in-situ precipitation) in a matrix. Our investigations have shown that nanocomposites prepared with solution chemistry were more favorable for producing uniform dispersion of nanoparticles. Structural information of nanocomposites was studied with transmission electron microscopy and the interection between particles and matrix polymers were tentatively probed using dielectric spectroscopy. In these new class of materials high energy densities on the order of 15J/cc were achievable in nanocomposites.展开更多
Predictive simulation of engine combustion is key to understanding the underlying complicated physicochemical processes,improving engine performance,and reducing pollutant emissions.Critical issues as turbulence model...Predictive simulation of engine combustion is key to understanding the underlying complicated physicochemical processes,improving engine performance,and reducing pollutant emissions.Critical issues as turbulence modeling,turbulence-chemistry interaction,and accommodation of detailed chemical kinetics in complex flows remain challenging and essential for highfidelity combustion simulation.This paper reviews the current status of the state-of-the-art large eddy simulation(LES)/probability density function(PDF)/detailed chemistry approach that can address the three challenging modelling issues.PDF as a subgrid model for LES is formulated and the hybrid mesh-particle method for LES/PDF simulations is described.Then the development need in micro-mixing models for the PDF simulations of turbulent premixed combustion is identified.Finally the different acceleration methods for detailed chemistry are reviewed and a combined strategy is proposed for further development.展开更多
基金We acknowledge the funding from the Canada Research Chairs program,the National Sciences and Engineering Research Council of Canada and Genome CanadaZM was supported in part by a Killam Predoctoral Scholarship from Dalhousie University.
文摘Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world’s largest grape gene banks,the grape germplasm collection of the United States Department of Agriculture.We find that phenological events throughout the growing season are correlated,and quantify the marked difference in size between table and wine grapes.By pairing publicly available historical phenotype data with genome-wide polymorphism data,we identify large effect loci controlling traits that have been targeted during domestication and breeding,including hermaphroditism,lighter skin pigmentation and muscat aroma.Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited,whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions.We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries.Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes.
基金The National Natural Science Fund Projeet(51575293,51622504)National Key R&D Program of China(2016YFB0100906)International Sci&Tech Cooperation Program of China(2016YFE0102200)~~
文摘目的从微生物角度探究重度低龄儿童龋(severe early childhood caries,S⁃ECC)患儿一次完成龋病治疗前、治疗后3个月内菌斑微生物群落构成和多样性的变化及治疗对于远期无龋状态维持的作用。方法S⁃ECC患儿在全身麻醉下一次完成龋病治疗,采集治疗前(C)、术后7 d(C⁃7D)、1个月(C⁃1M)、3个月(C⁃3M)无龋牙面集合菌斑,并纳入无龋儿童(CF)为对照组,分析治疗前后菌斑微生物群落短期内的动态改建过程。结果S⁃ECC组和CF组菌斑群落组成高度相似;组间α多样性指数差异无统计学意义(P>0.05);从相对丰度值分析,纤毛菌属、聚集杆菌属等在治疗后较术前下降(P<0.05),C⁃7D组血链球菌较C组上升并在3个月内逐渐下降;治疗前韦荣菌属、放线菌属、拟普雷沃菌属、二氧化碳嗜纤维菌属、变异链球菌在C组和CF组间存在显著差异(P<0.05),其中变异链球菌经治疗后的C⁃7D、C⁃1M组与CF组未存在显著差异,而C⁃3M组较CF组出现上升(P<0.01)。结论S⁃ECC患儿在接受治疗后菌群结构的迅速改变,并在治疗后1~3个月逐渐开始建立新的无龋状态下的平衡。核心微生物群的存在使得菌斑群落保持稳定,韦荣菌属、拟普雷沃菌属、变异链球菌等具备作为龋病菌斑微生物标记物潜能。
基金Research reported in this publication was supported by the National Heart,Lung,And Blood Institute of the National Institutes of Health,No.R01HL151561The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
文摘This review paper aims to summarize cardiac CT blooming artifacts,how they present clinically and what their root causes and potential solutions are.A literature survey was performed covering any publications with a specific interest in calcium blooming and stent blooming in cardiac CT.The claims from literature are compared and interpreted,aiming at narrowing down the root causes and most promising solutions for blooming artifacts.More than 30 journal publications were identified with specific relevance to blooming artifacts.The main reported causes of blooming artifacts are the partial volume effect,motion artifacts and beam hardening.The proposed solutions are classified as high-resolution CT hardware,high-resolution CT reconstruction,subtraction techniques and post-processing techniques,with a special emphasis on deep learning(DL)techniques.The partial volume effect is the leading cause of blooming artifacts.The partial volume effect can be minimized by increasing the CT spatial resolution through higherresolution CT hardware or advanced high-resolution CT reconstruction.In addition,DL techniques have shown great promise to correct for blooming artifacts.A combination of these techniques could avoid repeat scans for subtraction techniques.
文摘There are a great variety of commercial nickel alloys mainly because nickel is able to dissolve a large amount of alloying elements while maintaining a single ductile austenitic phase. Nickel alloys are generally designed for and used in highly aggressive environments, for example, those where stainless steels may experience pitting corrosion or environmentally assisted cracking. While nickel alloys are generally resistant to pitting corrosion in chloride-containing environments, they may be prone to crevice corrosion attack. Addition of chromium, molybdenum and tungsten increases the localized corrosion resistance of nickel alloys. This review on the resistance to localized corrosion of nickel alloys includes specific environments such as those present in oil and gas upstream operations, in the chemical process industry and in seawater service.
基金jointly supported by Shanghai Eastern-scholar program
文摘Composites of mesoporous carbon（CMK-3） and Co3 O4 nanosheets grown on nickel foam were successfully synthesized by a simple route. A bare Co3 O4 film was synthesized for comparison. With the addition of CMK-3, the Co3 O4 nanoparticles self-organize and agglomerate into nanosheets, showing a significant influence by CMK-3 on the morphology. The CMK-3/Co3 O4 exhibits an optimal specific capacitance of 1131.3 Fg^（-1） in 3 mol L-1 KOH aqueous electrolyte at 0.5 Ag-1, and a retention ratio of 91% over3000 cycles, both being much higher than that achieved from the bare Co3 O4 film（727 Fg^（-1） of specific capacitance, and 82% capacitance retention ratio）, indicating that the CMK-3/Co3 O4 nanosheets are very promising as electrode materials for supercapacitor applications.
文摘BACKGROUND Liver surgery has traditionally been characterized by the complexity of its procedures and potentially high rates of morbidity and mortality in inexperienced hands.The robotic approach has gradually been introduced in liver surgery and has increased notably in recent years.However,few centers currently perform robotic liver surgery and experiences in robot-assisted surgical procedures continue to be limited compared to the laparoscopic approach.AIM To analyze the outcomes and feasibility of an initial robotic liver program implemented in an experienced laparoscopic hepatobiliary center.METHODS A total of forty consecutive patients underwent robotic liver resection(da Vinci Xi,intuitive.com,United States)between June 2019 and January 2021.Patients were prospectively followed and retrospectively reviewed.Clinicopathological characteristics and perioperative and short-term outcomes were analyzed.Data are expressed as mean and standard deviation.The study was approved by the Institutional Review Board.RESULTS The mean age of patients was 59.55 years,of which 18(45%)were female.The mean body mass index was 29.41 kg/m^(2).Nine patients(22.5%)were cirrhotic.Patients were divided by type of resection as follows:Ten segmentectomies,three wedge resections,ten left lateral sectionectomies,six bisegmentectomies(two VVI bisegmentectomies and four IVb-V bisegmentectomies),two right anterior sectionectomies,five left hepatectomies and two right hepatectomies.Malignant lesions occurred in twenty-nine(72.5%)of the patients.The mean operative time was 258.11 min and two patients were transfused intraoperatively(5%).Inflow occlusion was used in thirty cases(75%)and the mean total clamping time was 32.62 min.There was a single conversion due to uncontrollable hemorrhage.Major postoperative complications(Clavien–Dindo>Ⅲb)occurred in three patients(7.5%)and mortality in one(2.5%).No patient required readmission to the hospital.The mean hospital stay was 5.6 d.CONCLUSION Although robotic hepatectomy is a safe and feasible procedure with favorable short-term outcomes,it involves a demanding learning curve that requires a high level of training,skill and dexterity.
基金Research reported in this publication was partially supported by NIH,Nos.R01EB031102,R01HL151561,and R01CA233888The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH。
文摘Deep learning(DL)has shown unprecedented performance for many image analysis and image enhancement tasks.Yet,solving large-scale inverse problems like tomographic reconstruction remains challenging for DL.These problems involve non-local and space-variant integral transforms between the input and output domains,for which no efficient neural network models are readily available.A prior attempt to solve tomographic reconstruction problems with supervised learning relied on a brute-force fully connected network and only allowed reconstruction with a 128^(4)system matrix size.This cannot practically scale to realistic data sizes such as 512^(4)and 512^(6)for three-dimensional datasets.Here we present a novel framework to solve such problems with DL by casting the original problem as a continuum of intermediate representations between the input and output domains.The original problem is broken down into a sequence of simpler transformations that can be well mapped onto an efficient hierarchical network architecture,with exponentially fewer parameters than a fully connected network would need.We applied the approach to computed tomography(CT)image reconstruction for a 5124 system matrix size.This work introduces a new kind of data-driven DL solver for full-size CT reconstruction without relying on the structure of direct(analytical)or iterative(numerical)inversion techniques.This work presents a feasibility demonstration of full-scale learnt reconstruction,whereas more developments will be needed to demonstrate superiority relative to traditional reconstruction approaches.The proposed approach is also extendable to other imaging problems such as emission and magnetic resonance reconstruction.More broadly,hierarchical DL opens the door to a new class of solvers for general inverse problems,which could potentially lead to improved signal-to-noise ratio,spatial resolution and computational efficiency in various areas.
文摘This paper focuses on the state space modeling approach and output torques prediction of torsional vibrations for variable speed wind turbines. The multi-body system model under study is mainly comprised of a wind turbine, a three stage planetary gear box and an induction generator. The masses-springs approach of shaft system differential equations is developed from Newton＇s law and Lagrange formulas. For an easy comprehension for electrical engineers and tutorial purpose, an electrical equivalent circuit of the system is proposed by using mechanical and electrical components similarities. Extensive numerical simulations are performed to investigate system mechanical resonances and impacts of damping factors on the system dynamic and stability.
文摘Nanodielectric composites have been developed in recent years attempting to improve the dielectric properties such as dielectric constant, dielectric strength and voltage endurance. Among various investigations, nanoparticle dispersion was particularly emphasized in this work. General Electric Global Research Center in Niskayuna NY USA has investigated various nanoparticles, nanocomposites and nanocomposite synthesis methods intending to understand particle dispersion and their impact on the nanocomposite dielectric properties. The breakdown strength and microstructures of the nanocomposites containing different particles were studied for projects related to capacitor and electrical insulation technologies. The nanocomposite synthesis methods either employed commerical nanoparticles or utilized nanoparticles that were self-assembled (in-situ precipitation) in a matrix. Our investigations have shown that nanocomposites prepared with solution chemistry were more favorable for producing uniform dispersion of nanoparticles. Structural information of nanocomposites was studied with transmission electron microscopy and the interection between particles and matrix polymers were tentatively probed using dielectric spectroscopy. In these new class of materials high energy densities on the order of 15J/cc were achievable in nanocomposites.
基金supported by the 111 Project(Grant No.B13001)by the Young Thousand Talents Program from the Organization Department of the Communist Party of China Central Committee
文摘Predictive simulation of engine combustion is key to understanding the underlying complicated physicochemical processes,improving engine performance,and reducing pollutant emissions.Critical issues as turbulence modeling,turbulence-chemistry interaction,and accommodation of detailed chemical kinetics in complex flows remain challenging and essential for highfidelity combustion simulation.This paper reviews the current status of the state-of-the-art large eddy simulation(LES)/probability density function(PDF)/detailed chemistry approach that can address the three challenging modelling issues.PDF as a subgrid model for LES is formulated and the hybrid mesh-particle method for LES/PDF simulations is described.Then the development need in micro-mixing models for the PDF simulations of turbulent premixed combustion is identified.Finally the different acceleration methods for detailed chemistry are reviewed and a combined strategy is proposed for further development.
