Antibiotic abuse now poses a grave threat to global ecology and bestirs public concerns about the residue issue in daily necessities.The traceability measurements along supply chain or logistic circulation have become...Antibiotic abuse now poses a grave threat to global ecology and bestirs public concerns about the residue issue in daily necessities.The traceability measurements along supply chain or logistic circulation have become increasingly essential given the labile nature of diverse synthetic residuals on site.In an attempt to answer this urgency,here a miniaturized fluorometric aptasensor prototype was contrived that catered to the point-of-care screening norm for two typical additives:chloramphenicol and enrofloxacin.The key target-indicating module worked in vitro based on the competitive binding-induced fluorescence recovery of fluorescein-labeled aptamers,which were photobleached beforehand in the format of double helix on burlike nanogold carriers.The“prickly”geometry of the latter not just enriched the capture probes at preferentially substrate-accessible spires;but also contributed to a tip-enhanced surface plasmon effect,sensitizing the signal-on during the duplex dissociation even at nanomolar threshold of the analytes.On the other hand,to encompass a full portable,a set of optical devices were mounted within a 3D-printed cartridge(adaptor)to converge the light beam and route it towards the detector,for which the smartphone camera came up in handy with a home-developed App for calibrating the emissive brightness.Enlightened by the high-dynamic-range compression,an imaging diagnostic algorithm was built in to grid and digitize each slide in the album for augmented detection performance.Thus,a novel bio-to-silico integration was invented that capable of in situ rapid reporting on the antibiotic presence with high sensitivity and selectivity.Further field practices in spiked milk on sales proved the precision and rudimentary feasibility of the well-assembled model of appliance,thus holding nice prospects in nonexpert(e.g.,family and local community)utilities for foodborne antibiotic identification.展开更多
Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent...Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.展开更多
Metric measurement of digitized shapes is commonly applied in optical measuring systems.In this letter,three shape-related factors defined by the authors are used in the construction of amultiple linear regression mod...Metric measurement of digitized shapes is commonly applied in optical measuring systems.In this letter,three shape-related factors defined by the authors are used in the construction of amultiple linear regression model which is utilized to compute the circumference of the convex shapes inmillimeter unit.The model is first built upon the relationship hypothesis and then its adequacy ismathematically validated.The results of applying the developed model to the given number of convexshapes in a finite circumferential length range suggest that,in terms of percent error,the model pre-cision is to satisfaction by being within±4%.The test also shows the model’s robustness against theshape’s orientation anisotropy.展开更多
Rock fracture mechanics and accurate characterization of rock fracture are crucial for understanding a variety of phenomena interested in geological engineering and geoscience.These phenomena range from very large-sca...Rock fracture mechanics and accurate characterization of rock fracture are crucial for understanding a variety of phenomena interested in geological engineering and geoscience.These phenomena range from very large-scale asymmetrical fault structures to the scale of engineering projects and laboratory-scale rock fracture tests.Comprehensive study can involve mechanical modeling,site or post-mortem investigations,and inspection on the point cloud of the source locations in the form of earthquake,microseismicity,or acoustic emission.This study presents a comprehensive data analysis on characterizing the forming of the asymmetrical damage zone around a laboratory mixed-mode rock fracture.We substantiate the presence of asymmetrical damage through qualitative analysis and demonstrate that measurement uncertainties cannot solely explain the observed asymmetry.The implications of this demonstration can be manifold.On a larger scale,it solidifies a mechanical model used for explaining the contribution of aseismic mechanisms to asymmetrical fault structures.On a laboratory scale,it exemplifies an alternative approach to understanding the observational difference between the source location and the in situ or post-mortem inspection on the rock fracture path.The mechanical model and the data analysis can be informative to the interpretations of other engineering practices as well,but may face different types of challenges.展开更多
Microwave diffraction tomography is a process to infer the internal structure of an objectfrom multiple angle views of microwave diffraction shadow. Being sensitive to variations in refractive index of the object, the...Microwave diffraction tomography is a process to infer the internal structure of an objectfrom multiple angle views of microwave diffraction shadow. Being sensitive to variations in refractive index of the object, the procedure can be used to measure permittivity distributions within dielectric objects and to image soft tissues for biomedical applications. The optimal resolution distance obtainable is half a wavelength, but this can rarely be achieved because of practical limitations. Some procedures, however, are available to improve the practical resolution. One, which is suitable for microwave tomography, is to use multiple angle views data and to combine the resulting images. The other, which is suitable for improving the image reconstruction resolution, is to use the digital filtering technique and the filtered backpropagation algorithm. A system operating over the X-band microwave frequency is described and some experimental results for objects in air are given.展开更多
Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon ...Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon transform and optimal algorithms, which extracts automatically roads on images of rural areas, images that were acquired by digital cameras and airborne laser scanners. The proposed method detects linear segments iteratively and starting from this it generates the centerlines of the roads. The method is based on an objective function which depends on three parameters related to the correlation between the cross-sections, spectral similarity and directions of the segments. Different tests were performed using aerial photos, Ikonos images and laser scanner data of an area located in the state of Parana （Brazil） and their results are presented and discussed. The quality of the detection of the roads centerlines was computed using several indexes - completeness, correctness and RMS. The values obtained reveal the good performance of the proposed methodology.展开更多
Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions...Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions parallel and perpendicular to the forearm. Methodology: Data from more than two hundred subjects were studied retrospectively. A DXA (GE Lunar Prodigy) scan of the forearm was performed on each subject to measure the bone mineral density (BMD) value at the location of ultra-distal radius, and an X-ray digital image of the same forearm was taken on the same day. The values of trabecular bone score along the direction perpendicular to the forearm, TBS<sub>x</sub>, and along the direction parallel to the forearm, TBS<sub>y</sub>, were calculated respectively. The statistics of TBS<sub>x</sub> and TBS<sub>y</sub> were calculated, and the anisotropy of the trabecular bone, which was defined as the ratio of TBS<sub>y</sub> to TBS<sub>x</sub> and changed with subjects’ BMD and age, was reported and analyzed. Results: The results show that the correlation coefficient between TBS<sub>x</sub> and TBS<sub>y</sub> was 0.72 (p BMD and age was reported. The results showed that decreased trabecular bone anisotropy was associated with deceased BMD and increased age in the subject group. Conclusions: This study shows that decreased trabecular bone anisotropy was associated with decreased BMD and increased age.展开更多
In this paper, we propose several improved neural networks and training strategy using data augmentation to segment human radius accurately and efficiently. This method can provide pixel-level segmentation accuracy th...In this paper, we propose several improved neural networks and training strategy using data augmentation to segment human radius accurately and efficiently. This method can provide pixel-level segmentation accuracy through the low-level features of the neural network, and automatically distinguish the classification of radius. The versatility and applicability can be effectively improved by learning and training digital X-ray images obtained from digital X-ray imaging systems of different manufacturers.展开更多
Background: When applied to trabecular bone X-ray images, a method for analyzing trabecular bone texture based on the initial slope of variogram (ISV) was used to assess the trabecular bone health. Methodology: Data f...Background: When applied to trabecular bone X-ray images, a method for analyzing trabecular bone texture based on the initial slope of variogram (ISV) was used to assess the trabecular bone health. Methodology: Data from more than two hundred subjects were retrospectively studied. For each subject, a DXA (GE Lunar Prodigy) scan of the forearm was performed, and bone mineral density (BMD) value was measured at the location of ultra-distal radius, X-ray digital image of the same forearm was taken on the same day, and ISV value over the same location of ultra-distal radius was calculated. Pearson’s correlation coefficients were calculated to examine the correlation between BMD and ISV of the trabecular bones located at the same ultra-distal radius. ISV values changed with subjects’ age were also reported. Results: The results show that ISV value was highly correlated with the DXA-measured BMD of the same trabecular bone located at the ultra-distal radius. The correlation coefficient between ISV and BMD with the 95% confident was 0.79 ± 0.09. They also demonstrated that the age-related changes in trabecular bone health and differentiated age patterns in males and females, respectively. The results showed that the decrease in BMD was accompanied by a decrease in the initial slope of variogram (ISV). Conclusions: This study suggests that ISV might be used to quantitatively evaluate trabecular health for osteoporosis and bone disease diagnosis.展开更多
The progressive failure characteristics of geomaterial are a remarkable and challenging topic in geotechnical engineering.To study the effect of salt content and temperature on the progressive failure characteristics ...The progressive failure characteristics of geomaterial are a remarkable and challenging topic in geotechnical engineering.To study the effect of salt content and temperature on the progressive failure characteristics of frozen sodium sulfate saline sandy soil,a series of uniaxial compression tests were performed by integrating digital image correlation(DIC)technology into the testing apparatus.The evolution law of the uniaxial compression strength(UCS),the failure strain,and the formation of the shear band of the frozen sodium sulfate saline sandy soil were analyzed.The test results show that within the scope of this study,with the increase of salt content,both the UCS and the shear band angle initially decrease with increasing salt content before showing an increase.In contrast,the failure strain and the width of the shear band exhibit an initial increase followed by a decrease in the samples.In addition,to investigate the brittle failure characteristics of frozen sodium sulfate saline sandy soil,two classic brittleness evaluation methods were employed to quantitatively assess the brittleness level for the soil samples.The findings suggest that the failure characteristics under all test conditions in this study belong to the transition stage between brittle and ductile,indicating that frozen sodium sulfate saline sandy soil exhibits certain brittle behavior under uniaxial compression conditions,and the brittleness index basically decreases and then increases with the rise in salt content.展开更多
The pervasive use of photo editing applications such as Photoshop and FaceTune has significantly altered societal beauty standards, particularly for individuals with skin of color, often leading to unrealistic expecta...The pervasive use of photo editing applications such as Photoshop and FaceTune has significantly altered societal beauty standards, particularly for individuals with skin of color, often leading to unrealistic expectations regarding skin appearance and health. These tools allow users to smooth skin textures, lighten skin tones, and erase imperfections, perpetuating Eurocentric beauty ideals that frequently marginalize the natural diversity of skin tones and textures. Consequently, individuals with skin of color may seek dermatological interventions—such as skin lightening treatments, aggressive acne scar revisions, and other cosmetic procedures—aimed at achieving appearances that align more closely with digitally manipulated images. This pursuit of an unattainable aesthetic can result in increased dissatisfaction with common skin conditions like hyperpigmentation and keloids, which are often misrepresented in edited photos. Additionally, the psychological impact of these alterations can exacerbate feelings of inadequacy, contributing to conditions such as anxiety and body dysmorphic disorder. Dermatologists face the dual challenge of addressing patients’ clinical needs while also managing their expectations shaped by digital enhancements. To combat this, it is essential for dermatologists to integrate patient education that emphasizes the beauty of diverse skin tones and the discrepancies between digital images and authentic skin health. By fostering an understanding of realistic outcomes and promoting the acceptance of natural skin characteristics, dermatologists can empower individuals with skin of color to prioritize authentic skin health over digitally influenced ideals, ultimately leading to more satisfying dermatological care and improved self-image.展开更多
The microstructure and fabric of rocks largely control their mechanical behavior,and their spatial variations can lead to anisotropic behavior.Metamorphic rocks such as gneiss exhibit anisotropy,and characterizing thi...The microstructure and fabric of rocks largely control their mechanical behavior,and their spatial variations can lead to anisotropic behavior.Metamorphic rocks such as gneiss exhibit anisotropy,and characterizing this anisotropy is crucial in geoscientific and engineering applications including geothermal plays,active fault zones,and mining sites.We investigate a foliated gneiss from the French River area of the Canadian Shield to determine its mechanical properties and assess the impact of anisotropy across different scales.We combined micro-scale experiments(e.g.nanoindentation and optical and electron microscopy),with meso-scale experiments(e.g.unconfined compressive strength(UCS)and indirect tensile test),to attempt bridging the micro-to meso-scale elastic property gap.Our results show that micro-and meso-mechanical properties of gneiss are orientation-dependent across scales.Young's modulus,upscaled from nanoindentation testing,varied between 51 GPa and 74 GPa,while meso-scale Young's modulus from UCS tests varied between 45 GPa and 54 GPa.The ultrasonic velocities(P-and S-wave)exhibited anisotropy of 26%and 24%,respectively,while the estimated UCS anisotropy was 30%,with the highest values observed in the direction parallel to the foliation.The direction of the mineral alignment forming the foliation plane plays a crucial role in determining the failure pattern of the rock.We observed predominantly tensile failure in samples with 0°–15°foliation plane angle,shear-slip failure for samples with 20°–65°,and a conjugate shear failure in the sample at 90°foliation plane angle to the loading direction.These findings provide insight into the anisotropic(orientation-dependent)characterization of foliated metamorphic rocks,which can be useful in rock engineering applications and numerical simulations.展开更多
Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to imp...Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments.In this study,we employed both unmanned aerial vehicles(UAVs)equipped with red–green–blue(RGB)camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence.A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/Jimai 22 were evaluated for senescence-related traits across three environments,spanning from heading to 35 d post-anthesis.The manual senescence rate(MSR)was quantified using the FLC and the active accumulated temperature,and UAV derived vegetation index were utilized to assess the stay-green rate(USG)facilitating the identification of senescent and stay-green lines.Results indicated that higher senescence rates significantly impacted grain yield,primarily by influencing thousand-kernel weight,and plant height.Quantitative trait loci(QTL)mapping for FLC,USG,and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits:among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages,with nine loci likely representing novel QTL.This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat,validating the relationship between senescence rates and yield-related traits in wheat,offering valuable opportunities for gene discovery and significant applications in breeding programs.展开更多
The semiconductor bridge(SCB)ignites through bridge film discharge,offering advantages such as low ignition energy,high safety,and compatibility with digital logic circuits.The study uses laser interferometry to inves...The semiconductor bridge(SCB)ignites through bridge film discharge,offering advantages such as low ignition energy,high safety,and compatibility with digital logic circuits.The study uses laser interferometry to investigate the gas dynamics of the bridge film after SCB plasma extinction.Interferometric images of the SCB film gas were obtained through a laser interferometry optical path.After the degradation model of digital image processing,clearer images were produced to facilitate analysis and calculation.The results show that the gas temperature at the center of the SCB film reaches a maximum of 1000 K,and the temperature rapidly decreases along the axial direction of the bridge surface to room temperature at 300 K.The maximum diffusion velocity of the plasma is 1.8 km/s.These findings provide critical insights for SCB design and ignition control.展开更多
To investigate the effects of the spraying process and different fibers on the mechanical properties and failure patterns of ultrahigh performance concrete(UHPC),three types of fibers were used.These fibers were forme...To investigate the effects of the spraying process and different fibers on the mechanical properties and failure patterns of ultrahigh performance concrete(UHPC),three types of fibers were used.These fibers were formed using both spraying and molding methods.Uniaxial compression tests were conducted,and two nondestructive monitoring techniques,acoustic emission(AE)and digital image correlation,were employed to monitor the uniaxial compression tests.The results indicated that the compressive strength of UHPC with single steel fibers and hybrid fibers increased by about 19%and 14%compared with those of UHPC with polyoxymethylene fibers.In comparison with molded UHPC,sprayed UHPC showed a slight improvement in compressive strength.Specimens containing steel fibers exhibited better post-cracking ductility,whereas those with only polyoxymethylene fibers displayed a certain degree of brittle failure.In sprayed UHPC,the onset of significant internal damage was delayed,which was related to the redistribution of internal fibers.The failure of UHPC was characterized by primary tensile cracks,supplemented by shear cracks.The spraying process can better restrict the development of tensile cracks in UHPC.Sprayed UHPC typically exhibited multiple crack developments leading to failure,whereas molded UHPC generally failed in the form of a single main crack penetrating the specimen.The addition of steel fibers delayed the occurrence of local stress concentration zones,aligning well with AE monitoring data.展开更多
Underground mine pillars provide natural stability to the mine area,allowing safe operations for workers and machinery.Extensive prior research has been conducted to understand pillar failure mechanics and design safe...Underground mine pillars provide natural stability to the mine area,allowing safe operations for workers and machinery.Extensive prior research has been conducted to understand pillar failure mechanics and design safe pillar layouts.However,limited studies(mostly based on empirical field observation and small-scale laboratory tests)have considered pillar-support interactions under monotonic loading conditions for the design of pillar-support systems.This study used a series of large-scale laboratory compression tests on porous limestone blocks to analyze rock and support behavior at a sufficiently large scale(specimens with edge length of 0.5 m)for incorporation of actual support elements,with consideration of different w/h ratios.Both unsupported and supported(grouted rebar rockbolt and wire mesh)tests were conducted,and the surface deformations of the specimens were monitored using three-dimensional(3D)digital image correlation(DIC).Rockbolts instrumented with distributed fiber optic strain sensors were used to study rockbolt strain distribution,load mobilization,and localized deformation at different w/h ratios.Both axial and bending strains were observed in the rockbolts,which became more prominent in the post-peak region of the stress-strain curve.展开更多
Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the ...Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the probability of catastrophic behavior in case of accidents.Equilibrium damage accumulation in some cases leads to a falling part(called a postcritical stage)on the material’s stress-strain curve.It must be taken into account to assess the strength and deformation limits of composite structures.Digital image correlation method,acoustic emission(AE)signals recording,and optical microscopy were used in this paper to study the deformation and failure processes of an orthogonal-layup composite during tension in various directions to orthotropy axes.An elastic-plastic deformation model was proposed for the composite in a plane stress condition.The evolution of strain fields and neck formation were analyzed.The staging of the postcritical deformation process was described.AE signals obtained during tests were studied;characteristic damage types of a material were defined.The rationality and necessity of polymer composites’postcritical deformation stage taken into account in refined strength analysis of structures were concluded.展开更多
The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significan...The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significance to accurately characterize the actual microstructures and their influence on stress and damage evolution inside the rocks. In this study, an image-based fast Fourier transform (FFT) method is developed for reconstructing the actual rock microstructures by combining it with the digital image processing (DIP) technique. A series of experimental investigations were conducted to acquire information regarding the actual microstructure and the mechanical properties. Based on these experimental evidences, the processed microstructure information, in conjunction with the proposed micromechanical model, is incorporated into the numerical calculation. The proposed image-based FFT method was firstly validated through uniaxial compression tests. Subsequently, it was employed to predict and analyze the influence of microstructure on macroscopic mechanical behaviors, local stress distribution and the internal crack evolution process in brittle rocks. The distribution of feldspar is considerably more heterogeneous and scattered than that of quartz, which results in a greater propensity for the formation of cracks in feldspar. It is observed that initial cracks and new cracks, including intragranular and boundary ones, ultimately coalesce and connect as the primary through cracks, which are predominantly distributed along the boundary of the feldspar. This phenomenon is also predicted by the proposed numerical method. The results indicate that the proposed numerical method provides an effective approach for analyzing, understanding and predicting the nonlinear mechanical and cracking behaviors of brittle rocks by taking into account the actual microstructure characteristics.展开更多
The use of artificial intelligence(AI)in wound care has become a crucial instrument in improving the diagnosis,treatment,and management of chronic wounds.This study examines the several functions of AI in wound care,e...The use of artificial intelligence(AI)in wound care has become a crucial instrument in improving the diagnosis,treatment,and management of chronic wounds.This study examines the several functions of AI in wound care,emphasizing its ability to better wound evaluation,hasten healing,alleviate pain,and improve cost-effectiveness.AI-driven technology,including mobile applications and intelligent bandages,provides precise wound assessment,tissue analysis,and continuous monitoring,hence allowing for tailored treatment strategies and prompt intervention.Moreover,AI-driven algorithms forecast wound healing trajectories and find individuals susceptible to chronic wounds,allowing prompt preventative interventions.There are also practical issues with integrating it into clinical practice.Adding AI to current healthcare systems,like electronic medical records(EMRs),needs careful planning and teamwork to make sure that AI-driven insights are used well in real-time clinical decision-making.To make sure AI is used safely,legal frameworks need to be set up to provide clear rules for its use in healthcare.These frameworks should include openness,risk management,and data evaluation.Lastly,clinical validation and acceptance are still big problems.Many AI-powered tools don't have enough clinical validation and aren't widely available,which makes it hard to use them in everyday clinical practice.Solving these problems is important for getting the most out of AI in wound care and making sure it is used safely and effectively.The article combines current advancements and prospective trajectories in AI-assisted wound care,highlighting its revolutionary ability to revolutionize patient outcomes and healthcare delivery.展开更多
基金supported by National Natural Science Foundation of China(Nos.21874071 and 22204077)China Postdoctoral Science Foundation(No.2021M701722)Fundamental Research Funds for the Central Universities(Nos.30921013112 and 30922010501)。
文摘Antibiotic abuse now poses a grave threat to global ecology and bestirs public concerns about the residue issue in daily necessities.The traceability measurements along supply chain or logistic circulation have become increasingly essential given the labile nature of diverse synthetic residuals on site.In an attempt to answer this urgency,here a miniaturized fluorometric aptasensor prototype was contrived that catered to the point-of-care screening norm for two typical additives:chloramphenicol and enrofloxacin.The key target-indicating module worked in vitro based on the competitive binding-induced fluorescence recovery of fluorescein-labeled aptamers,which were photobleached beforehand in the format of double helix on burlike nanogold carriers.The“prickly”geometry of the latter not just enriched the capture probes at preferentially substrate-accessible spires;but also contributed to a tip-enhanced surface plasmon effect,sensitizing the signal-on during the duplex dissociation even at nanomolar threshold of the analytes.On the other hand,to encompass a full portable,a set of optical devices were mounted within a 3D-printed cartridge(adaptor)to converge the light beam and route it towards the detector,for which the smartphone camera came up in handy with a home-developed App for calibrating the emissive brightness.Enlightened by the high-dynamic-range compression,an imaging diagnostic algorithm was built in to grid and digitize each slide in the album for augmented detection performance.Thus,a novel bio-to-silico integration was invented that capable of in situ rapid reporting on the antibiotic presence with high sensitivity and selectivity.Further field practices in spiked milk on sales proved the precision and rudimentary feasibility of the well-assembled model of appliance,thus holding nice prospects in nonexpert(e.g.,family and local community)utilities for foodborne antibiotic identification.
基金the support of the National Natural Science Foundation of China(Grant Nos.42207199,52179113,42272333)Zhejiang Postdoctoral Scientific Research Project(Grant Nos.ZJ2022155,ZJ2022156)。
文摘Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.
基金the Ningbo Natural Science Foundation(No.2006A610016)the Foundation of National EducationMinistry for Returned Overseas Students&Scholars(SRFfor ROCS,SEM.No.2006699).
文摘Metric measurement of digitized shapes is commonly applied in optical measuring systems.In this letter,three shape-related factors defined by the authors are used in the construction of amultiple linear regression model which is utilized to compute the circumference of the convex shapes inmillimeter unit.The model is first built upon the relationship hypothesis and then its adequacy ismathematically validated.The results of applying the developed model to the given number of convexshapes in a finite circumferential length range suggest that,in terms of percent error,the model pre-cision is to satisfaction by being within±4%.The test also shows the model’s robustness against theshape’s orientation anisotropy.
文摘Rock fracture mechanics and accurate characterization of rock fracture are crucial for understanding a variety of phenomena interested in geological engineering and geoscience.These phenomena range from very large-scale asymmetrical fault structures to the scale of engineering projects and laboratory-scale rock fracture tests.Comprehensive study can involve mechanical modeling,site or post-mortem investigations,and inspection on the point cloud of the source locations in the form of earthquake,microseismicity,or acoustic emission.This study presents a comprehensive data analysis on characterizing the forming of the asymmetrical damage zone around a laboratory mixed-mode rock fracture.We substantiate the presence of asymmetrical damage through qualitative analysis and demonstrate that measurement uncertainties cannot solely explain the observed asymmetry.The implications of this demonstration can be manifold.On a larger scale,it solidifies a mechanical model used for explaining the contribution of aseismic mechanisms to asymmetrical fault structures.On a laboratory scale,it exemplifies an alternative approach to understanding the observational difference between the source location and the in situ or post-mortem inspection on the rock fracture path.The mechanical model and the data analysis can be informative to the interpretations of other engineering practices as well,but may face different types of challenges.
文摘Microwave diffraction tomography is a process to infer the internal structure of an objectfrom multiple angle views of microwave diffraction shadow. Being sensitive to variations in refractive index of the object, the procedure can be used to measure permittivity distributions within dielectric objects and to image soft tissues for biomedical applications. The optimal resolution distance obtainable is half a wavelength, but this can rarely be achieved because of practical limitations. Some procedures, however, are available to improve the practical resolution. One, which is suitable for microwave tomography, is to use multiple angle views data and to combine the resulting images. The other, which is suitable for improving the image reconstruction resolution, is to use the digital filtering technique and the filtered backpropagation algorithm. A system operating over the X-band microwave frequency is described and some experimental results for objects in air are given.
文摘Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon transform and optimal algorithms, which extracts automatically roads on images of rural areas, images that were acquired by digital cameras and airborne laser scanners. The proposed method detects linear segments iteratively and starting from this it generates the centerlines of the roads. The method is based on an objective function which depends on three parameters related to the correlation between the cross-sections, spectral similarity and directions of the segments. Different tests were performed using aerial photos, Ikonos images and laser scanner data of an area located in the state of Parana （Brazil） and their results are presented and discussed. The quality of the detection of the roads centerlines was computed using several indexes - completeness, correctness and RMS. The values obtained reveal the good performance of the proposed methodology.
文摘Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions parallel and perpendicular to the forearm. Methodology: Data from more than two hundred subjects were studied retrospectively. A DXA (GE Lunar Prodigy) scan of the forearm was performed on each subject to measure the bone mineral density (BMD) value at the location of ultra-distal radius, and an X-ray digital image of the same forearm was taken on the same day. The values of trabecular bone score along the direction perpendicular to the forearm, TBS<sub>x</sub>, and along the direction parallel to the forearm, TBS<sub>y</sub>, were calculated respectively. The statistics of TBS<sub>x</sub> and TBS<sub>y</sub> were calculated, and the anisotropy of the trabecular bone, which was defined as the ratio of TBS<sub>y</sub> to TBS<sub>x</sub> and changed with subjects’ BMD and age, was reported and analyzed. Results: The results show that the correlation coefficient between TBS<sub>x</sub> and TBS<sub>y</sub> was 0.72 (p BMD and age was reported. The results showed that decreased trabecular bone anisotropy was associated with deceased BMD and increased age in the subject group. Conclusions: This study shows that decreased trabecular bone anisotropy was associated with decreased BMD and increased age.
文摘In this paper, we propose several improved neural networks and training strategy using data augmentation to segment human radius accurately and efficiently. This method can provide pixel-level segmentation accuracy through the low-level features of the neural network, and automatically distinguish the classification of radius. The versatility and applicability can be effectively improved by learning and training digital X-ray images obtained from digital X-ray imaging systems of different manufacturers.
文摘Background: When applied to trabecular bone X-ray images, a method for analyzing trabecular bone texture based on the initial slope of variogram (ISV) was used to assess the trabecular bone health. Methodology: Data from more than two hundred subjects were retrospectively studied. For each subject, a DXA (GE Lunar Prodigy) scan of the forearm was performed, and bone mineral density (BMD) value was measured at the location of ultra-distal radius, X-ray digital image of the same forearm was taken on the same day, and ISV value over the same location of ultra-distal radius was calculated. Pearson’s correlation coefficients were calculated to examine the correlation between BMD and ISV of the trabecular bones located at the same ultra-distal radius. ISV values changed with subjects’ age were also reported. Results: The results show that ISV value was highly correlated with the DXA-measured BMD of the same trabecular bone located at the ultra-distal radius. The correlation coefficient between ISV and BMD with the 95% confident was 0.79 ± 0.09. They also demonstrated that the age-related changes in trabecular bone health and differentiated age patterns in males and females, respectively. The results showed that the decrease in BMD was accompanied by a decrease in the initial slope of variogram (ISV). Conclusions: This study suggests that ISV might be used to quantitatively evaluate trabecular health for osteoporosis and bone disease diagnosis.
基金supported by the National Natural Science Foundation of China(Grant Nos.42372312,and 42172299)the Pyramid Talent Training Project of Beijing University of Civil Engineering and Architecture(Grant No.JDYC20220807).
文摘The progressive failure characteristics of geomaterial are a remarkable and challenging topic in geotechnical engineering.To study the effect of salt content and temperature on the progressive failure characteristics of frozen sodium sulfate saline sandy soil,a series of uniaxial compression tests were performed by integrating digital image correlation(DIC)technology into the testing apparatus.The evolution law of the uniaxial compression strength(UCS),the failure strain,and the formation of the shear band of the frozen sodium sulfate saline sandy soil were analyzed.The test results show that within the scope of this study,with the increase of salt content,both the UCS and the shear band angle initially decrease with increasing salt content before showing an increase.In contrast,the failure strain and the width of the shear band exhibit an initial increase followed by a decrease in the samples.In addition,to investigate the brittle failure characteristics of frozen sodium sulfate saline sandy soil,two classic brittleness evaluation methods were employed to quantitatively assess the brittleness level for the soil samples.The findings suggest that the failure characteristics under all test conditions in this study belong to the transition stage between brittle and ductile,indicating that frozen sodium sulfate saline sandy soil exhibits certain brittle behavior under uniaxial compression conditions,and the brittleness index basically decreases and then increases with the rise in salt content.
文摘The pervasive use of photo editing applications such as Photoshop and FaceTune has significantly altered societal beauty standards, particularly for individuals with skin of color, often leading to unrealistic expectations regarding skin appearance and health. These tools allow users to smooth skin textures, lighten skin tones, and erase imperfections, perpetuating Eurocentric beauty ideals that frequently marginalize the natural diversity of skin tones and textures. Consequently, individuals with skin of color may seek dermatological interventions—such as skin lightening treatments, aggressive acne scar revisions, and other cosmetic procedures—aimed at achieving appearances that align more closely with digitally manipulated images. This pursuit of an unattainable aesthetic can result in increased dissatisfaction with common skin conditions like hyperpigmentation and keloids, which are often misrepresented in edited photos. Additionally, the psychological impact of these alterations can exacerbate feelings of inadequacy, contributing to conditions such as anxiety and body dysmorphic disorder. Dermatologists face the dual challenge of addressing patients’ clinical needs while also managing their expectations shaped by digital enhancements. To combat this, it is essential for dermatologists to integrate patient education that emphasizes the beauty of diverse skin tones and the discrepancies between digital images and authentic skin health. By fostering an understanding of realistic outcomes and promoting the acceptance of natural skin characteristics, dermatologists can empower individuals with skin of color to prioritize authentic skin health over digitally influenced ideals, ultimately leading to more satisfying dermatological care and improved self-image.
基金funded by the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grants(Grant No.341275)the NSERC/Energi Simulation Industrial Research Chair program,and State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Open Fund(Grant No.SKLGP2024K001).
文摘The microstructure and fabric of rocks largely control their mechanical behavior,and their spatial variations can lead to anisotropic behavior.Metamorphic rocks such as gneiss exhibit anisotropy,and characterizing this anisotropy is crucial in geoscientific and engineering applications including geothermal plays,active fault zones,and mining sites.We investigate a foliated gneiss from the French River area of the Canadian Shield to determine its mechanical properties and assess the impact of anisotropy across different scales.We combined micro-scale experiments(e.g.nanoindentation and optical and electron microscopy),with meso-scale experiments(e.g.unconfined compressive strength(UCS)and indirect tensile test),to attempt bridging the micro-to meso-scale elastic property gap.Our results show that micro-and meso-mechanical properties of gneiss are orientation-dependent across scales.Young's modulus,upscaled from nanoindentation testing,varied between 51 GPa and 74 GPa,while meso-scale Young's modulus from UCS tests varied between 45 GPa and 54 GPa.The ultrasonic velocities(P-and S-wave)exhibited anisotropy of 26%and 24%,respectively,while the estimated UCS anisotropy was 30%,with the highest values observed in the direction parallel to the foliation.The direction of the mineral alignment forming the foliation plane plays a crucial role in determining the failure pattern of the rock.We observed predominantly tensile failure in samples with 0°–15°foliation plane angle,shear-slip failure for samples with 20°–65°,and a conjugate shear failure in the sample at 90°foliation plane angle to the loading direction.These findings provide insight into the anisotropic(orientation-dependent)characterization of foliated metamorphic rocks,which can be useful in rock engineering applications and numerical simulations.
基金funded by the National Key Research and Development Program of China(2022ZD0115703)the National Natural Science Foundation of China(32372196)+1 种基金the Beijing Joint Research Program for Germplasm Innovation and New Variety Breeding(G20220628002)National Natural Science Foundation of China(32250410307)。
文摘Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments.In this study,we employed both unmanned aerial vehicles(UAVs)equipped with red–green–blue(RGB)camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence.A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/Jimai 22 were evaluated for senescence-related traits across three environments,spanning from heading to 35 d post-anthesis.The manual senescence rate(MSR)was quantified using the FLC and the active accumulated temperature,and UAV derived vegetation index were utilized to assess the stay-green rate(USG)facilitating the identification of senescent and stay-green lines.Results indicated that higher senescence rates significantly impacted grain yield,primarily by influencing thousand-kernel weight,and plant height.Quantitative trait loci(QTL)mapping for FLC,USG,and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits:among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages,with nine loci likely representing novel QTL.This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat,validating the relationship between senescence rates and yield-related traits in wheat,offering valuable opportunities for gene discovery and significant applications in breeding programs.
基金supported by the Anhui Zhongchuang Energy New Energy Technology Co.,Ltd.,Entrusted Project.
文摘The semiconductor bridge(SCB)ignites through bridge film discharge,offering advantages such as low ignition energy,high safety,and compatibility with digital logic circuits.The study uses laser interferometry to investigate the gas dynamics of the bridge film after SCB plasma extinction.Interferometric images of the SCB film gas were obtained through a laser interferometry optical path.After the degradation model of digital image processing,clearer images were produced to facilitate analysis and calculation.The results show that the gas temperature at the center of the SCB film reaches a maximum of 1000 K,and the temperature rapidly decreases along the axial direction of the bridge surface to room temperature at 300 K.The maximum diffusion velocity of the plasma is 1.8 km/s.These findings provide critical insights for SCB design and ignition control.
基金The National Natural Science Foundation of China(No.52379124)the National Key Research and Development Program of China(No.2021YFB2600200).
文摘To investigate the effects of the spraying process and different fibers on the mechanical properties and failure patterns of ultrahigh performance concrete(UHPC),three types of fibers were used.These fibers were formed using both spraying and molding methods.Uniaxial compression tests were conducted,and two nondestructive monitoring techniques,acoustic emission(AE)and digital image correlation,were employed to monitor the uniaxial compression tests.The results indicated that the compressive strength of UHPC with single steel fibers and hybrid fibers increased by about 19%and 14%compared with those of UHPC with polyoxymethylene fibers.In comparison with molded UHPC,sprayed UHPC showed a slight improvement in compressive strength.Specimens containing steel fibers exhibited better post-cracking ductility,whereas those with only polyoxymethylene fibers displayed a certain degree of brittle failure.In sprayed UHPC,the onset of significant internal damage was delayed,which was related to the redistribution of internal fibers.The failure of UHPC was characterized by primary tensile cracks,supplemented by shear cracks.The spraying process can better restrict the development of tensile cracks in UHPC.Sprayed UHPC typically exhibited multiple crack developments leading to failure,whereas molded UHPC generally failed in the form of a single main crack penetrating the specimen.The addition of steel fibers delayed the occurrence of local stress concentration zones,aligning well with AE monitoring data.
基金the funding support from Alpha Foundation for the Improvement of Mine Safety and Health Inc.(ALPHAFOUNDATION,Grant No.AFC820-52)。
文摘Underground mine pillars provide natural stability to the mine area,allowing safe operations for workers and machinery.Extensive prior research has been conducted to understand pillar failure mechanics and design safe pillar layouts.However,limited studies(mostly based on empirical field observation and small-scale laboratory tests)have considered pillar-support interactions under monotonic loading conditions for the design of pillar-support systems.This study used a series of large-scale laboratory compression tests on porous limestone blocks to analyze rock and support behavior at a sufficiently large scale(specimens with edge length of 0.5 m)for incorporation of actual support elements,with consideration of different w/h ratios.Both unsupported and supported(grouted rebar rockbolt and wire mesh)tests were conducted,and the surface deformations of the specimens were monitored using three-dimensional(3D)digital image correlation(DIC).Rockbolts instrumented with distributed fiber optic strain sensors were used to study rockbolt strain distribution,load mobilization,and localized deformation at different w/h ratios.Both axial and bending strains were observed in the rockbolts,which became more prominent in the post-peak region of the stress-strain curve.
基金This work was supported by the Russian Science Foundation(Grant No.22-19-00765)at the Perm National Research Polytechnic University.
文摘Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the probability of catastrophic behavior in case of accidents.Equilibrium damage accumulation in some cases leads to a falling part(called a postcritical stage)on the material’s stress-strain curve.It must be taken into account to assess the strength and deformation limits of composite structures.Digital image correlation method,acoustic emission(AE)signals recording,and optical microscopy were used in this paper to study the deformation and failure processes of an orthogonal-layup composite during tension in various directions to orthotropy axes.An elastic-plastic deformation model was proposed for the composite in a plane stress condition.The evolution of strain fields and neck formation were analyzed.The staging of the postcritical deformation process was described.AE signals obtained during tests were studied;characteristic damage types of a material were defined.The rationality and necessity of polymer composites’postcritical deformation stage taken into account in refined strength analysis of structures were concluded.
基金supported by the National Natural Science Foundation of China(Grant No.11802332)the China Scholarship Council(Grant No.202206435003)the Fundamental Research Funds for the Central Universities(Grant No.2024ZKPYLJ03).
文摘The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significance to accurately characterize the actual microstructures and their influence on stress and damage evolution inside the rocks. In this study, an image-based fast Fourier transform (FFT) method is developed for reconstructing the actual rock microstructures by combining it with the digital image processing (DIP) technique. A series of experimental investigations were conducted to acquire information regarding the actual microstructure and the mechanical properties. Based on these experimental evidences, the processed microstructure information, in conjunction with the proposed micromechanical model, is incorporated into the numerical calculation. The proposed image-based FFT method was firstly validated through uniaxial compression tests. Subsequently, it was employed to predict and analyze the influence of microstructure on macroscopic mechanical behaviors, local stress distribution and the internal crack evolution process in brittle rocks. The distribution of feldspar is considerably more heterogeneous and scattered than that of quartz, which results in a greater propensity for the formation of cracks in feldspar. It is observed that initial cracks and new cracks, including intragranular and boundary ones, ultimately coalesce and connect as the primary through cracks, which are predominantly distributed along the boundary of the feldspar. This phenomenon is also predicted by the proposed numerical method. The results indicate that the proposed numerical method provides an effective approach for analyzing, understanding and predicting the nonlinear mechanical and cracking behaviors of brittle rocks by taking into account the actual microstructure characteristics.
文摘The use of artificial intelligence(AI)in wound care has become a crucial instrument in improving the diagnosis,treatment,and management of chronic wounds.This study examines the several functions of AI in wound care,emphasizing its ability to better wound evaluation,hasten healing,alleviate pain,and improve cost-effectiveness.AI-driven technology,including mobile applications and intelligent bandages,provides precise wound assessment,tissue analysis,and continuous monitoring,hence allowing for tailored treatment strategies and prompt intervention.Moreover,AI-driven algorithms forecast wound healing trajectories and find individuals susceptible to chronic wounds,allowing prompt preventative interventions.There are also practical issues with integrating it into clinical practice.Adding AI to current healthcare systems,like electronic medical records(EMRs),needs careful planning and teamwork to make sure that AI-driven insights are used well in real-time clinical decision-making.To make sure AI is used safely,legal frameworks need to be set up to provide clear rules for its use in healthcare.These frameworks should include openness,risk management,and data evaluation.Lastly,clinical validation and acceptance are still big problems.Many AI-powered tools don't have enough clinical validation and aren't widely available,which makes it hard to use them in everyday clinical practice.Solving these problems is important for getting the most out of AI in wound care and making sure it is used safely and effectively.The article combines current advancements and prospective trajectories in AI-assisted wound care,highlighting its revolutionary ability to revolutionize patient outcomes and healthcare delivery.
