Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bid...Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bidirectional interactions between tumor cells and cells that make up bone result in a selective advantage for tumor growth and can lead to bone destruction or new bone matrix deposition. This review discusses our current understanding of the molecu- lar components and mechanisms that are responsible for those interactions.展开更多
The Materials Genome Initiative(MGI)advanced a new paradigm for materials discovery and design,namely that the pace of new materials deployment could be accelerated through complementary efforts in theory,computation,...The Materials Genome Initiative(MGI)advanced a new paradigm for materials discovery and design,namely that the pace of new materials deployment could be accelerated through complementary efforts in theory,computation,and experiment.Along with numerous successes,new challenges are inviting researchers to refocus the efforts and approaches that were originally inspired by the MGI.In May 2017,the National Science Foundation sponsored the workshop“Advancing and Accelerating Materials Innovation Through the Synergistic Interaction among Computation,Experiment,and Theory:Opening New Frontiers”to review accomplishments that emerged from investments in science and infrastructure under the MGI,identify scientific opportunities in this new environment,examine how to effectively utilize new materials innovation infrastructure,and discuss challenges in achieving accelerated materials research through the seamless integration of experiment,computation,and theory.This article summarizes key findings from the workshop and provides perspectives that aim to guide the direction of future materials research and its translation into societal impacts.展开更多
Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells（MSC） to secrete brain-derived neurotrophic factor（BDNF） supports our plan to submit an Investigational N...Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells（MSC） to secrete brain-derived neurotrophic factor（BDNF） supports our plan to submit an Investigational New Drug application to the Food and Drug Administration for the future planned Phase 1 safety and tolerability trial of MSC/BDNF in patients with Huntington＇s disease（HD）. There are also potential applications of this approach beyond HD. Our biological delivery system for BDNF sets the precedent for adult stem cell therapy in the brain and could potentially be modified for other neurodegenerative disorders such as amyotrophic lateral sclerosis（ALS）, spinocerebellar ataxia（SCA）, Alzheimer＇s disease, and some forms of Parkinson＇s disease. The MSC/BDNF product could also be considered for studies of regeneration in traumatic brain injury, spinal cord and peripheral nerve injury. This work also provides a platform for our future gene editing studies, since we will again use MSCs to deliver the needed molecules into the central nervous system.展开更多
Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, o...Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, or obsessive-compulsive disorder (OCD), whose symptoms are exacerbated by group A streptococcal (GAS) infection. PANDAS has been known to cause a sudden onset of reward deficiency syndrome (RDS). RDS includes multiple disorders that are characterized by dopaminergic signaling dysfunction in the brain reward cascade (BRC), which may result in addiction, depression, avoidant behaviors, anxiety, tic disorders, and/or OCD. According to research by Blum et al., the dopamine receptor D2 (DRD2) gene polymorphisms are important prevalent genetic determinants of RDS. The literature demonstrates that infections like Borrelia and Lyme, as well as other infections like group A beta-hemolytic streptococcal (GABHS), can cause an autoimmune reaction and associated antibodies target dopaminergic loci in the mesolimbic region of the brain, which interferes with brain function and potentially causes RDS-like symptoms/behaviors. The treatment of PANDAS remains controversial, especially since there have been limited efficacy studies to date. We propose an innovative potential treatment for PANDAS based on previous clinical trials using a pro-dopamine regulator known as KB220 variants. Our ongoing research suggests that achieving “dopamine homeostasis” by precision-guided DNA testing and pro-dopamine modulation could result in improved therapeutic outcomes.展开更多
Selection of appropriate thermomechanical processing parameters is crucial for control of the crystallographic texture and grain size distribution in wrought magnesium alloys, which in turn dictate their mechanical pr...Selection of appropriate thermomechanical processing parameters is crucial for control of the crystallographic texture and grain size distribution in wrought magnesium alloys, which in turn dictate their mechanical properties. In this work, the recrystallization behavior of binary Mg-Zn alloys are examined after warm rolling as a function of alloy content and heat treatment temperature. The Avrami exponent increased with increasing heat treatment temperature up to the Mg Zn solvus, while the strength of the recrystallization texture decreased.Neither the Avrami exponent nor the qualitative trends in texture evolution were sensitive to the Zn alloying content in the examined range.EBSD and transmission electron microscopy observations revealed that the changes in texture and recrystallization kinetics could be attributed to differences in the nucleation behavior of basal and off-basal orientations.展开更多
Due to coal’s availability and low cost, coal combustion continues to be the United States’ primary energy source. However, coal combustion produces large quantities of waste material. Some coal combustion by-produc...Due to coal’s availability and low cost, coal combustion continues to be the United States’ primary energy source. However, coal combustion produces large quantities of waste material. Some coal combustion by-products (CCBs) have chemical and physical characteristics that make them potentially useful as soil amendments. The objectives of this study were to characterize a relatively new, high-calcium dry flue gas desulfurization (DFGD) by-product and compare its agronomic liming potential to a Class-C fly ash (FA) and reagent-grade calcium carbonate (CaCO3). Calcium car-bonate equivalence (CCE), degree of fineness (DOF), and effective neutralizing value (ENV) for each CCB were determined using standard methods. The CCBs and CaCO3 were also incubated with an acidic (~4.5) clay sub-soil at application rates equiva-lent to 0, 0.5, 1, and 2 times the soil’s lime requirement and compared to an una-mended control. Soil pH was then measured periodically during a 40-day incubation. The ENV of 79.4% for the DFGD by-product and 57.3% for the FA were comparable to those of commercially available liming materials, but were significantly lower (P < 0.05) than that of reagent-grade CaCO3. After 40 days of incubation at the 0.5× ap-plication rate, both CCBs raised the pH of the clay soil to only 5.0, while the CaCO3 raised the pH to 6.5. After 40 days at the 1× rate, all three materials had raised the soil pH to between 6.5 and 7.0, although the FA increased the soil pH more slowly than did the other two materials. At the 2× rate, both CCBs increased the soil pH to between 7.5 and 8.0, while the CaCO3 increased the soil pH to only 7.0. Both CCBs appear to be useful as soil liming materials, although care should be taken to avoid over-application, as this may make the soil too alkaline for optimum plant growth.展开更多
This paper develops a Bayesian inference-based probabilistic crack nucleation model for the Ni-based superalloy René88DT under fatigue loading.A data-driven,machine learning approach is developed,identifying unde...This paper develops a Bayesian inference-based probabilistic crack nucleation model for the Ni-based superalloy René88DT under fatigue loading.A data-driven,machine learning approach is developed,identifying underlying mechanisms driving crack nucleation.An experimental set of fatigue-loaded microstructures is characterized near crack nucleation sites using scanning electron microscopy and electron backscatter diffraction images for correlating the grain morphology and crystallography to the location of crack nucleation sites.A concurrent multiscale model,embedding experimental polycrystalline microstructural representative volume elements(RVEs)in a homogenized material,is developed for fatigue simulations.The RVE domain is modeled by a crystal plasticity finite element model.An anisotropic continuum plasticity model,obtained by homogenization of the crystal plasticity model,is used for the exterior domain.A Bayesian classification method is introduced to optimally select informative state variable predictors of crack nucleation.From this principal set of state variables,a simple scalar crack nucleation indicator is formulated.展开更多
Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to ident...Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution.This review evaluates the state of the field,beginning with a physics-based understanding of acoustic emission waveform feature extraction,followed by a detailed overview of waveform clustering,labeling,and error analysis strategies.Fundamental requirements for damage mechanism identification in any machine learning framework,including those currently in use,under development,and yet to be explored,are discussed.展开更多
BackgroundAcne affects 83- 95% of 16- year-oldsof both sexes, and many seek help from a clinician. Emerging problems with conventional acne treatments, specifically antibiotic resistance of Propionibacterium acnes and...BackgroundAcne affects 83- 95% of 16- year-oldsof both sexes, and many seek help from a clinician. Emerging problems with conventional acne treatments, specifically antibiotic resistance of Propionibacterium acnes and fears over th e safety and tolerance of oral isotretinoin, create a demand for novel treatment modalities in acne. Objectives To study the efficacy of aminolaevulinic acid- photodynamic therapy (ALA-PDT) in the treatment of acne and to identify the mode of acti on, looking specifically at the effects on surface numbers of P. acnes and on se bum excretion. Methods Ten patients (nine men and one woman, age range 16- 40 y ears) with mild to moderate acne on their backswere recruited. Each patient’s backwasmarkedwith four 30- cm2 areas of equal acne severity. Each site was then randomly allocated to either ALA-PDT treatment, light alone, ALAalone or an u ntreated control site. At baseline, numbers of inflammatory and noninflammatory acne lesions were counted, sebum excretionmeasured by Sebutapes (CuDerm, Dallas, TX, U.S.A.) and surface P. acnes swabs performed. ALA cream (20% in Unguentum Merck) was applied under occlusion to the ALA-PDT and ALA alone sites for 3 h . Red light from a diode laser was then delivered to the ALA-PDT and light alo ne sites (635 nm, 25 mW cm- 2, 15 J cm- 2). Each patient was treated weekly fo r 3 weeks. At each visit acne lesion counts were performed and 3 weeks following the last treatment sebum excretion rates and P. acnes swabs were repeated. Resu lts There was a statistically significant reduction in inflammatory acne lesion counts from baseline after the second treatment at the ALA-PDT site but not at any of the other sites. No statistically significant reduction in P. acnes numb ers or sebum excretion was demonstrated at any sites including the ALA-PDT sit e. Conclusions ALA-PDT is capable of clinically improving acne. An alternative mode of action for ALA-PDT other than direct damage to sebaceous glands or ph otodynamickilling of P. acnes is suggested from the result展开更多
Magnetic sensing is present in our everyday interactions with consumer electronics and demonstrates the potential for the measurement of extremely weak biomagnetic fields,such as those of the heart and brain.In this w...Magnetic sensing is present in our everyday interactions with consumer electronics and demonstrates the potential for the measurement of extremely weak biomagnetic fields,such as those of the heart and brain.In this work,we leverage the many benefits of microelectromechanical system(MEMS)devices to fabricate a small,low-power,and inexpensive sensor whose resolution is in the range of biomagnetic fields.At present,biomagnetic fields are measured only by expensive mechanisms such as optical pumping and superconducting quantum interference devices(SQUIDs),suggesting a large opportunity for MEMS technology in this work.The prototype fabrication is achieved by assembling micro-objects,including a permanent micromagnet,onto a postrelease commercial MEMS accelerometer using a pick-and-place technique.With this system,we demonstrate a room-temperature MEMS magnetic gradiometer.In air,the sensor’s response is linear,with a resolution of 1.1 nT cm^(−1),spans over 3 decades of dynamic range to 4.6µT cm^(−1),and is capable of off-resonance measurements at low frequencies.In a 1mTorr vacuum with 20 dB magnetic shielding,the sensor achieves a 100 pT cm^(−1) resolution at resonance.This resolution represents a 30-fold improvement compared with that of MEMS magnetometer technology and a 1000-fold improvement compared with that of MEMS gradiometer technology.The sensor is capable of a small spatial resolution with a magnetic sensing element of 0.25 mm along its sensitive axis,a>4-fold improvement compared with that of MEMS gradiometer technology.The calculated noise floor of this platform is 110 fTcm^(−1) Hz−1/2,and thus,these devices hold promise for both magnetocardiography(MCG)and magnetoencephalography(MEG)applications.展开更多
OBJECTIVE: To investigate the efficacy of Ciji Hua'ai Baosheng formula(CHBF) on microvessel density(MVD) and vascular endothelial growth factor(VEGF), kinase insert domain-containing receptor(KDR) and basic fibrob...OBJECTIVE: To investigate the efficacy of Ciji Hua'ai Baosheng formula(CHBF) on microvessel density(MVD) and vascular endothelial growth factor(VEGF), kinase insert domain-containing receptor(KDR) and basic fibroblast growth factor(b FGF) expression in serum and tumor tissue of mice receiving chemotherapy for the treatment of H22 hepatocellular carcinoma.METHODS: Sixty Kunming mice were injected subcutaneously with H22 hepatoma carcinoma cell suspensions into the right anterior armpit. Seven days later, all transplanted tumor were formed and the mice were intraperitoneally injected 200 mg/kg cytoxan(CTX) to establish the models of tumor-bearing mouse chemotherapy, then they were randomly divided into model group, continuing CTX chemotherapy group(CTX group), and three CHBF(117, 58.5 and 29.25 g/kg) groups. After ten days of treatments, histology was observed, contents of VEGF, KDR and b FGF in serum and tumor tissue were measured by enzyme-linked immunosorbent assay(ELISA), VEGF and b FGF protein expression and MVD tagged by CD34 were detected by immunohistochemisty.RESULTS: MVD in CHBF(117, 58.5 g/kg) and CTX groups was significantly lower than that in model group(P < 0.01); expressions of VEGF, KDR and b FGF in serum and tumor tissue in CHBF(117 g/kg)group were less than those in model group(P <0.05; P < 0.01); the expressions of MVD, VEGF and b FGF in tumor tissue of CHBF(117 g/kg) groupwere also less than those in CTX group(P < 0.05;P < 0.01).CONCLUSION: CHBF can effectively reduce the expression of VEGF, KDR and b FGF in serum and tumor tissue, and decrease MVD and delay tumor progression.展开更多
In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC c...In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering.Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and fiber.Importantly,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge agnostic.Additionally,the partitions were highly precise across both the model and location of the sensors,and the partitioning was repeatable.The presented approach is promising for CMCs and other composite systems with elastically similar constituents.展开更多
In computer vision,single-image super-resolution(SISR)has been extensively explored using convolutional neural networks(CNNs)on optical images,but images outside this domain,such as those from scientific experiments,a...In computer vision,single-image super-resolution(SISR)has been extensively explored using convolutional neural networks(CNNs)on optical images,but images outside this domain,such as those from scientific experiments,are not well investigated.Experimental data is often gathered using non-optical methods,which alters the metrics for image quality.One such example is electron backscatter diffraction(EBSD),a materials characterization technique that maps crystal arrangement in solid materials,which provides insight into processing,structure,and property relationships.We present a broadly adaptable approach for applying state-of-art SISR networks to generate super-resolved EBSD orientation maps.This approach includes quaternion-based orientation recognition,loss functions that consider rotational effects and crystallographic symmetry,and an inference pipeline to convert network output into established visualization formats for EBSD maps.The ability to generate physically accurate,high-resolution EBSD maps with super-resolution enables high-throughput characterization and broadens the capture capabilities for three-dimensional experimental EBSD datasets.展开更多
文摘Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bidirectional interactions between tumor cells and cells that make up bone result in a selective advantage for tumor growth and can lead to bone destruction or new bone matrix deposition. This review discusses our current understanding of the molecu- lar components and mechanisms that are responsible for those interactions.
文摘The Materials Genome Initiative(MGI)advanced a new paradigm for materials discovery and design,namely that the pace of new materials deployment could be accelerated through complementary efforts in theory,computation,and experiment.Along with numerous successes,new challenges are inviting researchers to refocus the efforts and approaches that were originally inspired by the MGI.In May 2017,the National Science Foundation sponsored the workshop“Advancing and Accelerating Materials Innovation Through the Synergistic Interaction among Computation,Experiment,and Theory:Opening New Frontiers”to review accomplishments that emerged from investments in science and infrastructure under the MGI,identify scientific opportunities in this new environment,examine how to effectively utilize new materials innovation infrastructure,and discuss challenges in achieving accelerated materials research through the seamless integration of experiment,computation,and theory.This article summarizes key findings from the workshop and provides perspectives that aim to guide the direction of future materials research and its translation into societal impacts.
基金provided by a NIH NIGMS Predoctoral Fellowship T32GM099608(Deng)NIH NRSA Postdoctoral Fellowship F32NS090722(Fink)+2 种基金a NIH Director’s transformative award 1R01GM099688(Nolta)A Stewart’s and Dake Family Gift(Fink),California Institute for Regenerative Medicine(CIRM)DR2-05415(Wheelock/Nolta)philanthropic donors from the HD community,including the Roberson family and Team KJ
文摘Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells（MSC） to secrete brain-derived neurotrophic factor（BDNF） supports our plan to submit an Investigational New Drug application to the Food and Drug Administration for the future planned Phase 1 safety and tolerability trial of MSC/BDNF in patients with Huntington＇s disease（HD）. There are also potential applications of this approach beyond HD. Our biological delivery system for BDNF sets the precedent for adult stem cell therapy in the brain and could potentially be modified for other neurodegenerative disorders such as amyotrophic lateral sclerosis（ALS）, spinocerebellar ataxia（SCA）, Alzheimer＇s disease, and some forms of Parkinson＇s disease. The MSC/BDNF product could also be considered for studies of regeneration in traumatic brain injury, spinal cord and peripheral nerve injury. This work also provides a platform for our future gene editing studies, since we will again use MSCs to deliver the needed molecules into the central nervous system.
文摘Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, or obsessive-compulsive disorder (OCD), whose symptoms are exacerbated by group A streptococcal (GAS) infection. PANDAS has been known to cause a sudden onset of reward deficiency syndrome (RDS). RDS includes multiple disorders that are characterized by dopaminergic signaling dysfunction in the brain reward cascade (BRC), which may result in addiction, depression, avoidant behaviors, anxiety, tic disorders, and/or OCD. According to research by Blum et al., the dopamine receptor D2 (DRD2) gene polymorphisms are important prevalent genetic determinants of RDS. The literature demonstrates that infections like Borrelia and Lyme, as well as other infections like group A beta-hemolytic streptococcal (GABHS), can cause an autoimmune reaction and associated antibodies target dopaminergic loci in the mesolimbic region of the brain, which interferes with brain function and potentially causes RDS-like symptoms/behaviors. The treatment of PANDAS remains controversial, especially since there have been limited efficacy studies to date. We propose an innovative potential treatment for PANDAS based on previous clinical trials using a pro-dopamine regulator known as KB220 variants. Our ongoing research suggests that achieving “dopamine homeostasis” by precision-guided DNA testing and pro-dopamine modulation could result in improved therapeutic outcomes.
基金the University of California Santa Barbara for the support of a Regents’ Special Fellowshipthe support of Office of Naval Research Grant number N00014-17-1-2810+3 种基金supported by the MRSEC Program of the NSF under Award No. DMR 1121053a member of the NSF-funded Materials Research Facilities Network (www.mrfn.org)partially supported by the IMI Program of the National Science Foundation under Award No. DMR 08-43934the support of the Australian Research Council。
文摘Selection of appropriate thermomechanical processing parameters is crucial for control of the crystallographic texture and grain size distribution in wrought magnesium alloys, which in turn dictate their mechanical properties. In this work, the recrystallization behavior of binary Mg-Zn alloys are examined after warm rolling as a function of alloy content and heat treatment temperature. The Avrami exponent increased with increasing heat treatment temperature up to the Mg Zn solvus, while the strength of the recrystallization texture decreased.Neither the Avrami exponent nor the qualitative trends in texture evolution were sensitive to the Zn alloying content in the examined range.EBSD and transmission electron microscopy observations revealed that the changes in texture and recrystallization kinetics could be attributed to differences in the nucleation behavior of basal and off-basal orientations.
文摘Due to coal’s availability and low cost, coal combustion continues to be the United States’ primary energy source. However, coal combustion produces large quantities of waste material. Some coal combustion by-products (CCBs) have chemical and physical characteristics that make them potentially useful as soil amendments. The objectives of this study were to characterize a relatively new, high-calcium dry flue gas desulfurization (DFGD) by-product and compare its agronomic liming potential to a Class-C fly ash (FA) and reagent-grade calcium carbonate (CaCO3). Calcium car-bonate equivalence (CCE), degree of fineness (DOF), and effective neutralizing value (ENV) for each CCB were determined using standard methods. The CCBs and CaCO3 were also incubated with an acidic (~4.5) clay sub-soil at application rates equiva-lent to 0, 0.5, 1, and 2 times the soil’s lime requirement and compared to an una-mended control. Soil pH was then measured periodically during a 40-day incubation. The ENV of 79.4% for the DFGD by-product and 57.3% for the FA were comparable to those of commercially available liming materials, but were significantly lower (P < 0.05) than that of reagent-grade CaCO3. After 40 days of incubation at the 0.5× ap-plication rate, both CCBs raised the pH of the clay soil to only 5.0, while the CaCO3 raised the pH to 6.5. After 40 days at the 1× rate, all three materials had raised the soil pH to between 6.5 and 7.0, although the FA increased the soil pH more slowly than did the other two materials. At the 2× rate, both CCBs increased the soil pH to between 7.5 and 8.0, while the CaCO3 increased the soil pH to only 7.0. Both CCBs appear to be useful as soil liming materials, although care should be taken to avoid over-application, as this may make the soil too alkaline for optimum plant growth.
基金This work has been supported through Grant No.CMMI-1825115 from the National Science Foundation awarded by the Mechanics of Materials and Structures(MOMS)Program(Program Manager:Dr.Siddiq Qidwai)Early stages of this work was supported through a grant No.FA9550-12-1-0445 to the Center of Excellence on Integrated Materials Modeling(CEIMM)at Johns Hopkins University awarded by the AFOSR/RSL Computational Mathematics Program(Managers Dr.Fariba Fahroo and Dr.A.Sayir).
文摘This paper develops a Bayesian inference-based probabilistic crack nucleation model for the Ni-based superalloy René88DT under fatigue loading.A data-driven,machine learning approach is developed,identifying underlying mechanisms driving crack nucleation.An experimental set of fatigue-loaded microstructures is characterized near crack nucleation sites using scanning electron microscopy and electron backscatter diffraction images for correlating the grain morphology and crystallography to the location of crack nucleation sites.A concurrent multiscale model,embedding experimental polycrystalline microstructural representative volume elements(RVEs)in a homogenized material,is developed for fatigue simulations.The RVE domain is modeled by a crystal plasticity finite element model.An anisotropic continuum plasticity model,obtained by homogenization of the crystal plasticity model,is used for the exterior domain.A Bayesian classification method is introduced to optimally select informative state variable predictors of crack nucleation.From this principal set of state variables,a simple scalar crack nucleation indicator is formulated.
基金CM.and B.S.gratefully acknowledge financial support from the NASA Spce Tochnology Gaduate Research Opportunites Felowship(Grants:8ONSSC19K1164 and 8ONSSC17K0084,SD.and T.MP.gratefully acknowiedge fnanchl support from the Natonal Sclonce Found ation Uward 1984641)patt of the HDR IDEAS Insatute.The authors additonally thank Aaron Engel for the suggeston for this project and Dr Neal Brodnik for an Introduction to tSNE。
文摘Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution.This review evaluates the state of the field,beginning with a physics-based understanding of acoustic emission waveform feature extraction,followed by a detailed overview of waveform clustering,labeling,and error analysis strategies.Fundamental requirements for damage mechanism identification in any machine learning framework,including those currently in use,under development,and yet to be explored,are discussed.
文摘BackgroundAcne affects 83- 95% of 16- year-oldsof both sexes, and many seek help from a clinician. Emerging problems with conventional acne treatments, specifically antibiotic resistance of Propionibacterium acnes and fears over th e safety and tolerance of oral isotretinoin, create a demand for novel treatment modalities in acne. Objectives To study the efficacy of aminolaevulinic acid- photodynamic therapy (ALA-PDT) in the treatment of acne and to identify the mode of acti on, looking specifically at the effects on surface numbers of P. acnes and on se bum excretion. Methods Ten patients (nine men and one woman, age range 16- 40 y ears) with mild to moderate acne on their backswere recruited. Each patient’s backwasmarkedwith four 30- cm2 areas of equal acne severity. Each site was then randomly allocated to either ALA-PDT treatment, light alone, ALAalone or an u ntreated control site. At baseline, numbers of inflammatory and noninflammatory acne lesions were counted, sebum excretionmeasured by Sebutapes (CuDerm, Dallas, TX, U.S.A.) and surface P. acnes swabs performed. ALA cream (20% in Unguentum Merck) was applied under occlusion to the ALA-PDT and ALA alone sites for 3 h . Red light from a diode laser was then delivered to the ALA-PDT and light alo ne sites (635 nm, 25 mW cm- 2, 15 J cm- 2). Each patient was treated weekly fo r 3 weeks. At each visit acne lesion counts were performed and 3 weeks following the last treatment sebum excretion rates and P. acnes swabs were repeated. Resu lts There was a statistically significant reduction in inflammatory acne lesion counts from baseline after the second treatment at the ALA-PDT site but not at any of the other sites. No statistically significant reduction in P. acnes numb ers or sebum excretion was demonstrated at any sites including the ALA-PDT sit e. Conclusions ALA-PDT is capable of clinically improving acne. An alternative mode of action for ALA-PDT other than direct damage to sebaceous glands or ph otodynamickilling of P. acnes is suggested from the result
基金This work was supported by the NSF CELL-MET ERC award no.1647837 and a SONY Faculty Innovation Award.
文摘Magnetic sensing is present in our everyday interactions with consumer electronics and demonstrates the potential for the measurement of extremely weak biomagnetic fields,such as those of the heart and brain.In this work,we leverage the many benefits of microelectromechanical system(MEMS)devices to fabricate a small,low-power,and inexpensive sensor whose resolution is in the range of biomagnetic fields.At present,biomagnetic fields are measured only by expensive mechanisms such as optical pumping and superconducting quantum interference devices(SQUIDs),suggesting a large opportunity for MEMS technology in this work.The prototype fabrication is achieved by assembling micro-objects,including a permanent micromagnet,onto a postrelease commercial MEMS accelerometer using a pick-and-place technique.With this system,we demonstrate a room-temperature MEMS magnetic gradiometer.In air,the sensor’s response is linear,with a resolution of 1.1 nT cm^(−1),spans over 3 decades of dynamic range to 4.6µT cm^(−1),and is capable of off-resonance measurements at low frequencies.In a 1mTorr vacuum with 20 dB magnetic shielding,the sensor achieves a 100 pT cm^(−1) resolution at resonance.This resolution represents a 30-fold improvement compared with that of MEMS magnetometer technology and a 1000-fold improvement compared with that of MEMS gradiometer technology.The sensor is capable of a small spatial resolution with a magnetic sensing element of 0.25 mm along its sensitive axis,a>4-fold improvement compared with that of MEMS gradiometer technology.The calculated noise floor of this platform is 110 fTcm^(−1) Hz−1/2,and thus,these devices hold promise for both magnetocardiography(MCG)and magnetoencephalography(MEG)applications.
基金the National Natural Science Foundation of China(From Regulating Pathological Angiogenesis and the Hepatic Fibrosis Way to Compare the Effects and Mechanisms between Taohongsiwu Decoction and its Absorbed Bioactive Compound,No.81202659)the Xiamen Science and Technology Key Program Plan Grant(Prevention and Treatment Mechanism Study of Traditional Chinese Medicine on Common Digestive Tract Cancer of Fujian and Taiwan,No.3502Z20100006)+2 种基金the Xiamen Science and Technology Program Plan Grant(the Development and Application and Basic Research of Ciji Hua'ai Baosheng Soluble Granules,No.3502Z20153027)the Natural Science Foundation of Fujian(China)(Negative Effect of Safflower Ingredient and Taohong formula on Mechanism of Pathological Angiogenesis and PI3K-Akt Signaling,No.2014J01373)the Scientific Research Start Foundation for New Teacher of Xiamen University(Correlated Mechanism Study of Safflower Ingredient Regulating Digestive Tract Tumor,No.ZK1014)
文摘OBJECTIVE: To investigate the efficacy of Ciji Hua'ai Baosheng formula(CHBF) on microvessel density(MVD) and vascular endothelial growth factor(VEGF), kinase insert domain-containing receptor(KDR) and basic fibroblast growth factor(b FGF) expression in serum and tumor tissue of mice receiving chemotherapy for the treatment of H22 hepatocellular carcinoma.METHODS: Sixty Kunming mice were injected subcutaneously with H22 hepatoma carcinoma cell suspensions into the right anterior armpit. Seven days later, all transplanted tumor were formed and the mice were intraperitoneally injected 200 mg/kg cytoxan(CTX) to establish the models of tumor-bearing mouse chemotherapy, then they were randomly divided into model group, continuing CTX chemotherapy group(CTX group), and three CHBF(117, 58.5 and 29.25 g/kg) groups. After ten days of treatments, histology was observed, contents of VEGF, KDR and b FGF in serum and tumor tissue were measured by enzyme-linked immunosorbent assay(ELISA), VEGF and b FGF protein expression and MVD tagged by CD34 were detected by immunohistochemisty.RESULTS: MVD in CHBF(117, 58.5 g/kg) and CTX groups was significantly lower than that in model group(P < 0.01); expressions of VEGF, KDR and b FGF in serum and tumor tissue in CHBF(117 g/kg)group were less than those in model group(P <0.05; P < 0.01); the expressions of MVD, VEGF and b FGF in tumor tissue of CHBF(117 g/kg) groupwere also less than those in CTX group(P < 0.05;P < 0.01).CONCLUSION: CHBF can effectively reduce the expression of VEGF, KDR and b FGF in serum and tumor tissue, and decrease MVD and delay tumor progression.
基金C.M.and B.S.gratefully acknowledge financial support from the NASA Space Technology Research Grant Program(Grants:80NSSC19K1164 and 80NSSC17K0084)S.D.and T.M.P.gratefully acknowledge financial support from the National Science Foundation(Award:1934641)as part of the HDR IDEAS2 Institute.The authors thank Abed Musaffar for creating the CAD schematic in Fig.1a and thank Dr.Neal Brodnik for a detailed introduction to t-SNE.
文摘In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering.Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and fiber.Importantly,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge agnostic.Additionally,the partitions were highly precise across both the model and location of the sensors,and the partitioning was repeatable.The presented approach is promising for CMCs and other composite systems with elastically similar constituents.
基金This research is supported in part by NSF awards number 1934641 and 1664172The MRL Shared Experimental Facilities are supported by the MRSEC Program of the NSF under Award No.DMR 1720256+5 种基金a member of the NSF-funded Materials Research Facilities Network(www.mrfn.org)Use was also made of computational facilities purchased with funds from the National Science Foundation(CNS-1725797)and administered by the Center for Scientific Computing(CSC)The CSC is supported by the California NanoSystems Institute and the Materials Research Science and Engineering Center(MRSECNSF DMR 1720256)at UC Santa BarbaraUse was made of the computational facilities purchased with funds from the National Science Foundation CC*Compute grant(OAC-1925717)and administered by the Center for Scientific Computing(CSC)The ONR Grant N00014-19-2129 is also acknowledged for the titanium datasets.
文摘In computer vision,single-image super-resolution(SISR)has been extensively explored using convolutional neural networks(CNNs)on optical images,but images outside this domain,such as those from scientific experiments,are not well investigated.Experimental data is often gathered using non-optical methods,which alters the metrics for image quality.One such example is electron backscatter diffraction(EBSD),a materials characterization technique that maps crystal arrangement in solid materials,which provides insight into processing,structure,and property relationships.We present a broadly adaptable approach for applying state-of-art SISR networks to generate super-resolved EBSD orientation maps.This approach includes quaternion-based orientation recognition,loss functions that consider rotational effects and crystallographic symmetry,and an inference pipeline to convert network output into established visualization formats for EBSD maps.The ability to generate physically accurate,high-resolution EBSD maps with super-resolution enables high-throughput characterization and broadens the capture capabilities for three-dimensional experimental EBSD datasets.
