A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourie...A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.展开更多
Although a few pristine metal-organic frameworks(MOFs) of graphene analogue topology exhibit high intrinsic electrical conductivity, their use in lithium-ion batteries(LIBs) is still hampered by unfavorable Li+adsorpt...Although a few pristine metal-organic frameworks(MOFs) of graphene analogue topology exhibit high intrinsic electrical conductivity, their use in lithium-ion batteries(LIBs) is still hampered by unfavorable Li+adsorption energy(ΔEa). In this paper, an electroconductive ferrocene-based MOF@MXene heterostructure is built to provide stable anodes for Li+storage. Charge density difference and planar average potential charge density show substantial redistribution of charges at the interfaces, transferring from MXene to MOF layers. Moreover, density functional theory(DFT) calculations reveal that the interaction between MXene and MOF significantly increases the ΔEa. As a result, the heterostructure anode exhibits high capacities and outstanding cycling stability with a capacity retention of 80% after 5000 cycles at 5 A g^(-1), outperforming mono-component MXene and MOF. Furthermore, the heterostructure anode is built into a full cell with a commercial NCM 532 cathode, delivering a high energy density of 611 Wh kg^(-1)and power density of 7600 W kg^(-1). The developed conductive MOF@MXene heterogeneity for improved LIB offers valuable insights into the design of advanced electrode materials for energy storage.展开更多
Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for hi...Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for high speed operation. However, because of its complex irregular structure, the manufacturing process using silicon sheets is complicated. Soft magnetic composite material(SMC) is manufactured by powder metallurgy technology, which can produce various shapes of stator core structures, so it is easier to produce various irregular shapes of the stator core. However, the raw SMC material is relatively expensive, and the mechanical strength of SMC is weak. In this paper, a PMCPM with hybrid cores is proposed. With the adoption of hybrid silicon sheet-SMC cores and amorphous alloy-SMC cores, the torque ability of PMCPM can be improved greatly and it can have higher efficiency for more wide operation frequency. Meanwhile, its mechanical strength has been improved and it can be designed for high torque direct drive applications as it is a modular machine. Furthermore, three methods are proposed to reduce the additional eddy current loss which resulted from the employment of hybrid cores in PMCPM.展开更多
Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current ...Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current loss,and simple manufacturing process.The permanent magnet claw pole machine(PMCPM)with SMC cores is a good case that the SMC to be adopted for developing 3D flux electrical machines.In this paper,a novel axial-radial flux permanent magnet claw pole machine(ARPMCPM)with SMC cores and ferrite magnets is proposed.Compared with the traditional PMCPM,the proposed ARPMCPM is designed with only one spoke PM rotor and its whole structure is quite compact.For the performance prediction,the 3D finite element method(FEM)is used.Meanwhile,for the performance evaluation,a previously developed axial flux claw pole permanent magnet machine(AFCPM)is employed as the benchmark machine and all these machines are optimized by using the combined multilevel robust Taguchi method.It can be seen that the proposed ARPMCPM is with higher torque/weight density and operation efficiency.展开更多
Objective:Population-level economic burden is essential for prioritizing healthcare resources and healthcare budget making in the future.However,little is known about the economic burden of lung cancer in China.Method...Objective:Population-level economic burden is essential for prioritizing healthcare resources and healthcare budget making in the future.However,little is known about the economic burden of lung cancer in China.Methods:A prevalence-based approach was adopted to estimate the economic burden of lung cancer,including direct expenditure(medical and non-medical)and indirect cost(disability and premature death).Data on direct expenditure and work-loss days per patient in each year post-diagnosis were obtained from two primary surveys.Other parameters were obtained from literatures and official reports.Projections were conducted based on varying parameters.All expenditure data were reported in United States dollars(USD)using 2017 value(exchange rate:1 USD=6.760 CNY),with the discount rate of 3%.Results:The total economic burden of lung cancer was estimated to be 25,069 million USD in China in 2017(0.121%of gross domestic productivity,GDP).The estimated direct expenditure was 11,098 million USD,up to1.43%of total healthcare expenditure for China,covering 10,303 million USD and 795 million USD for medical and non-medical expenditure,respectively.The estimated indirect cost was 13,971 million,including 1,517 million USD due to disability and 12,454 million USD due to premature death.Under current assumptions,the projected total economic burden would increase to 30.1 billion USD,40.4 billion USD,and 53.4 billion USD in 2020,2025,and 2030,accounting for 0.121%,0.131%,and 0.146%of China's GDP,respectively.However,if China meets the United Nation sustainable development goal of reducing premature death from non-communicable diseases by one-third by 2030,the total economic burden in 2030 would be 31.9 billion USD,0.087%of China's GDP.Conclusions:The economic burden of lung cancer in China in 2017 is substantial and more likely to increase significantly in the future.Policy makers need to take urgent actions in budget making for health systems.The economic burden could be alleviated by reducing the disease burden of lung cancer via effective control and prevention actions.展开更多
Objective: Colorectal cancer(CRC) causes a substantial burden of disease in China and the evidence of economic burden triggered is fundamental for priority setting. The aim of this survey was to quantify medical expen...Objective: Colorectal cancer(CRC) causes a substantial burden of disease in China and the evidence of economic burden triggered is fundamental for priority setting. The aim of this survey was to quantify medical expenditures and the time trends for CRC diagnosis and treatment in China.Methods: From 2012 to 2014, a hospital-based multicenter retrospective survey was conducted in 13 provinces across China. For each eligible CRC patient diagnosed from 2002 to 2011, clinical information and expenditure data were extracted using a uniform questionnaire. All expenditure data were reported in Chinese Yuan(CNY)using 2011 values.Results: Of the 14,536 CRC patients included, the average age at diagnosis was 58.2 years and 15.8% were stageI cases. The average medical expenditure per patient was estimated at 37,902 CNY [95 % confidence interval(95%CI): 37,282-38,522], and the annual average increase rate was 9.2% from 2002 to 2011(P for trend <0.001), with a cumulative increase of 2.4 times(from 23,275 CNY to 56,010 CNY). The expenditure per patient in stages Ⅰ, Ⅱ, Ⅲ and Ⅳ were 31,698 CNY, 37,067 CNY, 38,918 CNY and 42,614 CNY, respectively(P<0.001). Expenditure significantly differed within various subgroups. Expenses for drugs contributed the largest proportion(52.6%).Conclusions: These conservative estimates illustrated that medical expenditures for CRC diagnosis and treatment in tertiary hospitals in China were substantial and increased rapidly over the 10 years, with drugs continually being the main expense by 2011. Relatively, medical expenditures are lower for CRC in the earlier stages. These findings will facilitate the economic evaluation of CRC prevention and control in China.展开更多
Objective:The number of liver cancer patients in China accounts for more than half of the world.However,China currently lacks national,multicenter economic burden data,and meanwhile,measuring the differences among dif...Objective:The number of liver cancer patients in China accounts for more than half of the world.However,China currently lacks national,multicenter economic burden data,and meanwhile,measuring the differences among different subgroups will be informative to formulate corresponding policies in liver cancer control.Thus,the aim of the study was to measure the economic burden of liver cancer by various subgroups.Methods:A hospital-based,multicenter and cross-sectional survey was conducted during 2012・2014,covering 39 hospitals and 21 project sites in 13 provinces across China.The questionnaire covers clinical information,sociology,expenditure,and related variables.All expenditure data were reported in Chinese Yuan(CNY)using 2014 values.Results:A total of 2,223 liver cancer patients were enrolled,of whom 59.61%were late-stage cases(III-IV),and 53.8%were hepatocellular carcinoma.The average total expenditure per liver cancer patient was estimated as 53,220 CNY,including 48,612 CNY of medical expenditures(91.3%)and 4,608 CNY of non-medical expenditures(8.7%).The average total expenditures in stage I,H,m and stage IV were 52,817 CNY,50,877 CNY,50,678 CNY and 54,089 CNY(P>0.05),respectively.Non-medical expenditures including additional meals,additional nutrition care,transportation,accommodation and hired informal nursing were 1,453 CNY,839 CNY,946 CNY,679 CNY and 200 CNY,respectively.The one-year out-of-pocket expenditure of a newly diagnosed patient was 24,953 CNY,and 77.2%of the patients suffered an unmanageable financial burden.Multivariate analysis showed that overall expenditure differed in almost all subgroups(P<0.05),except for sex,clinical stage,and pathologic type.Conclusions:There was no difference in treatment expenditure for liver cancer patients at different clinical stages,which suggests that maintaining efforts on treatment efficacy improvement is important but not enough.To fiirtherly reduce the overall economic burden from liver cancer,more effort should be given to primary and secondary prevention strategies.展开更多
Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic (UBBD) instrument and an in vivo application for neonatal bone eval...Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic (UBBD) instrument and an in vivo application for neonatal bone evaluation are introduced in this study. The UBBD provides several advantages, including noninvasiveness, non- ionizing radiation, portability, and simplicity. In this study, the backscatter signal could be measured within 5 s using the UBBD. Ultrasonic backscatter measurements were performed on 467 neonates (268 males and 199 females) at the left calcaneus. The backscatter signal was measured at a central frequency of 3.5 MHz. The delay (-/-1) and duration (7-2) of the backscatter signal of interest (SOl) were varied, and the apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), zero frequency intercept of apparent backscatter (FIAB), and spectral centroid shift (SCS) were calculated. The results showed that the SOl selection had a direct influence on cancellous bone evaluation. The AIB and FIAB were positively correlated with the gestational age (|R| up to 0.45, P 〈 0.001) when -/-1 was short (〈 8 μS), while negative correlations (|R| up to 0.56, P 〈 0.001) were commonly observed for T1 〉 10 IJS. Moderate positive correlations (IRI up to 0.45, P 〈 0.001) were observed for FSAB and SCS with gestational age when 71 was long (〉 10 μs). The 7-2 mainly introduced fluctuations in the observed correlation coefficients. The moderate correlations observed with UBBD demonstrate the feasibility of using the backscatter signal to evaluate neonatal bone status. This study also proposes an explicit standard for in vivo SOl selection and neonatal cancellous bone assessment.展开更多
The goal of this study is to analyze the statistics of the backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone charact...The goal of this study is to analyze the statistics of the backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone characterization. Ultrasonic backscatter measurements were performed on 24 bovine cancellous bone specimens in vitro and the backscatter signals were compensated for the frequency-dependent attenuation prior to the envelope detection. The statistics of the backscatter envelope were modeled using the Nakagami distribution. Our results reveal that the backscatter envelope mainly followed pre-Rayleigh distributions, and the deviations of the backscatter envelope from Rayleigh distribution decreased with increasing bone density. The Nakagami shape parameter(i.e., m) was significantly correlated with bone densities(R = 0.78–0.81, p < 0.001) and trabecular microstructures(|R| = 0.46–0.78, p < 0.05). The scale parameter(i.e.,?) and signal-to-noise ratio(SNR) also yielded significant correlations with bone density and structural features. Multiple linear regressions showed that bone volume fraction(BV/TV) was the main predictor of the Nakagami parameters,and microstructure produced significantly independent contribution to the prediction of Nakagami distribution parameters,explaining an additional 10.2% of the variance at most. The in vitro study showed that statistical parameters derived with Nakagami model might be useful for cancellous bone characterization, and statistical analysis has potential for ultrasonic backscatter bone evaluation.展开更多
As there is no need of permanent magnet(PM)material and only silicon steel sheet required on the rotor,synchronous reluctance machine(SynRM)can be used for many applications and draws a great research interest.For the...As there is no need of permanent magnet(PM)material and only silicon steel sheet required on the rotor,synchronous reluctance machine(SynRM)can be used for many applications and draws a great research interest.For the SynRM,the torque ripple is a big issue and a great of work could been done on reducing it.In this paper,asymmetrical magnetic flux barriers in the SynRM rotor were studied comprehensively,including angle and width of each layer and each side of the magnetic barrier.The SynRMb with asymmetrical and parallel magnetic flux barrier was found as the best way to design SynRM based on the multi-objective design optimization method.Moreover,each parameter was studied to show the design rule of the asymmetrical magnetic flux barrier.As the average torque will be reduced with the asymmetrical barrier is used,the grain-oriented silicon steel is used on stator teeth of the SynRMb(SynRMbG)was proposed and studied.The analysis results show that the proposed new method can make the SynRM have better performance.展开更多
The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalitie...The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalities to give accurate ultrasound images for irregular bone boundaries and microstructures using uniform sound velocity assumption rather than getting a prior knowledge of sound speed. To overcome these limitations, this paper proposed a frequency-domain fullwaveform inversion(FDFWI) algorithm for bone quantitative imaging utilizing ultrasonic computed tomography(USCT).The forward model was calculated in the frequency domain by solving the full-wave equation. The inverse problem was solved iteratively from low to high discrete frequency components via minimizing a cost function between the modeled and measured data. A quasi-Newton method called the limited-memory Broyden–Fletcher–Goldfarb–Shanno algorithm(L-BFGS) was utilized in the optimization process. Then, bone images were obtained based on the estimation of the velocity and density. The performance of the proposed method was verified by numerical examples, from tubular bone phantom to single distal fibula model, and finally with a distal tibia-fibula pair model. Compared with the high-resolution peripheral quantitative computed tomography(HR-p QCT), the proposed FDFWI can also clearly and accurately presented the wavelength scaled pores and trabeculae in bone images. The results proved that the FDFWI is capable of reconstructing high-resolution ultrasound bone images with sub-millimeter resolution. The parametric bone images may have the potential for the diagnosis of bone disease.展开更多
In agriculture production,plant health is threatened by pathogens parasitic on seeds;hence,it is necessary to disinfect harvested seeds before germination.In this study,a technique of gliding arc plasma treatment was ...In agriculture production,plant health is threatened by pathogens parasitic on seeds;hence,it is necessary to disinfect harvested seeds before germination.In this study,a technique of gliding arc plasma treatment was proposed and investigated.The experiment was conducted to treat Astragalus membranaceus(A.membranaceus)seeds that were artificially infected with Fusarium oxysporum(F.oxysporum).The plasma treatment duration varied from 30 s to 270 s.Direct and indirect treatments were compared to evaluate the inactivation efficiency of the F.oxysporum spores on the surface of seeds.The results indicated that the direct treatment behaved significantly better in disinfection than the indirect way.Meanwhile,experiments of the quantitative assessment of seed germination were also conducted,including the germination rate,the germination potential,and the germination index.The results showed that the inactivation efficiency increased as the plasma treatment time was extended.When the treatment time was90 s,the inactivation efficiency reached more than 98%.The plasma treatment of 270 s had a complete devitalization of F.oxysporum spores on the surface of the seeds.After the treatment of 30 s and 90 s,the seed germination parameters improved significantly.This study verified the inactivation efficacy of gliding arc discharge plasma under atmospheric pressure.The technique of gliding arc treatment shows advantages of energy saving and adaptation and has the potential to be utilized in industry.展开更多
Postmenopausal osteoporosis (PMO) is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidit...Postmenopausal osteoporosis (PMO) is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidity and serious complications of PMO, many efforts have been devoted to its prophylaxis and treatment. The intestinal microbiota is the complex community of microorganisms colonizing the gastrointestinal tract. Probiotics, which are dietary or medical supplements consisting of beneficial intestinal bacteria, work in concert with endogenous intestinal microorganisms to maintain host health. Recent studies have revealed that bone loss in PMO is closely related to host immunity, which is influenced by the intestinal microbiota. The curative effects of probiotics on metabolic bone diseases have also been demonstrated. The effects of the intestinal microbiota on bone metabolism suggest a promising target for PMO management. This review seeks to summarize the critical effects of the intestinal microbiota and probiotics on PMO, with a focus on the molecular mechanisms underlying the pathogenic relationship between bacteria and host, and to define the possible treatment options.展开更多
In recent years,with high-speed development of economy and society,and fast propulsion of industrialization and urbanization process in the development zone,average annual land demand in the development zone also quic...In recent years,with high-speed development of economy and society,and fast propulsion of industrialization and urbanization process in the development zone,average annual land demand in the development zone also quickly enlarges,and the contradiction between high-speed growth of economy and shortage of land resources is apparent increasingly. Meanwhile,to guarantee crop safety and stick to 0. 12 billion hm2of farmland red line as a rigid constraint which could not be exceeded,the supply-demand contradiction of industrial land is more and more prominent. With industrial land scale continues to enlarge,land resources become more and more scarce,but there exists the phenomenon of low-efficiency land use and even idle. For land use characteristics of the development zone,taking Hefei City Economic and Technological Development Zone as an example,the countermeasures of perfecting industrial land transfer mechanism in the development zone are proposed.展开更多
The performance of traditional flux switching permanent magnet tubular machine(FSPMTM)are improved by using new material and structure in this paper.The existing silicon steel sheet making for all mover cores or part ...The performance of traditional flux switching permanent magnet tubular machine(FSPMTM)are improved by using new material and structure in this paper.The existing silicon steel sheet making for all mover cores or part of stator cores are replaced by soft magnetic composite(SMC)cores,and the lamination direction of the silicon steel sheet in stator cores have be changed.The eddy current loss of the machine with hybrid cores will be reduced greatly as the magnetic flux will not pass through the silicon steel sheet vertically.In order to reduce the influence of end effect,the unequal stator width design method is proposed.With the new design,the symmetry of the permanent magnet flux linkage has been improved greatly and the cogging force caused by the end effect has been reduced.Both 2-D and 3-D finite element methods(FEM)are applied for the quantitative analysis.展开更多
This paper proposes a new rotary flux switching transverse flux machine with the ability of linear motion(FSTFMaLM),in which both the stator and the rotor cores are made by using soft magnetic composite(SMC)materials....This paper proposes a new rotary flux switching transverse flux machine with the ability of linear motion(FSTFMaLM),in which both the stator and the rotor cores are made by using soft magnetic composite(SMC)materials.With the special design pattern,for the rotary motion model,the proposed machine can combine both the advantages of the flux switching permanent magnet machine(FSPMM)and the transverse flux machine(TFM).It can output with relatively high torque density,and as there is no windings or the magnets on the rotor cores,the proposed machine can operate in the high speed region to improve the output power.With the adoption of the SMC materials,the manufacturing of this machine can be quite easy.By stacking the rotor core together and prolong it with the determined length in the axial direction,in addition with the special control algorithm,the proposed machine can have the ability of the linear motion.In this paper,the operation principle of this machine has been explained and the design methods are also presented.To seek the better performance,the main dimension of the machine is optimized,and for the performance evaluation,the finite element method(FEM)is adopted.The proposed machine can be used for the electric driving systems,robotic systems or other applications where the linear motion ability is required.展开更多
The ultrasonic backscatter(UB)has the advantage of non-invasively obtaining bone density and structure,expected to be an assessment tool for early diagnosis osteoporosis.All former UB measurements were based on exciti...The ultrasonic backscatter(UB)has the advantage of non-invasively obtaining bone density and structure,expected to be an assessment tool for early diagnosis osteoporosis.All former UB measurements were based on exciting a short single-pulse and analyzing the ultrasonic signals backscattered in bone.This study aims to examine amplitude modulation(AM)ultrasonic excitation with UB measurements for predicting bone characteristics.The AM multiple lengths excitation and backscatter measurement(AM-UB)functions were integrated into a portable ultrasonic instrument for bone characterization.The apparent integrated backscatter coefficient in the AM excitation(AIB_(AM))was evaluated on the AM-UB instrumentation.The correlation coefficients of the AIB_(AM) estimating volume fraction(BV/TV),structure model index(SMI),and bone mineral density(BMD)were then analyzed.Significant correlations(|R|=0.82-0.93,p<0.05)were observed between the AIB_(AM),BV/TV,SMI,and BMD.By growing the AM excitation length,the AIB_(AM) values exhibit more stability both in 1.0-MHz and 3.5-MHz measurements.The recommendations in AM-UB measurement were that the avoided length(T1)should be lower than AM excitation length,and the analysis length(T2)should be enough long but not more than AM excitation length.The authors conducted an AM-UB measurement for cancellous bone characterization.Increasing the AM excitation length could substantially enhance AIB_(AM) values stability with varying analyzed signals.The study suggests the portable AM-UB instrument with the integration of real-time analytics software that might provide a potential tool for osteoporosis early screening.展开更多
In medical images, exist often a lot of noise, the noise will seriously affect the accuracy of the segmentation results. The traditional standard fuzzy c-means(FCM) algorithm in image segmentation do not taken into ac...In medical images, exist often a lot of noise, the noise will seriously affect the accuracy of the segmentation results. The traditional standard fuzzy c-means(FCM) algorithm in image segmentation do not taken into account the relationship the adjacent pixels, which leads to the standard fuzzy c-means(FCM) algorithm is very sensitive to noise in the image. Proposed improvedfuzzy c-means(FCM) algorithm, taking both the local and non-local information into the standard fuzzy c-means(FCM) clustering algorithm. The ex-periment results can show that the improved algorithm can achieve better effect than other methods of brain tissue segmentation.展开更多
This study aims to introduce the protocol for ultrasonic backscatter measurements of musculoskeletal properties based on a novel ultrasonic backscatter bone diagnostic(UBBD)instrument.Dual-energy X-ray absorptiometry(...This study aims to introduce the protocol for ultrasonic backscatter measurements of musculoskeletal properties based on a novel ultrasonic backscatter bone diagnostic(UBBD)instrument.Dual-energy X-ray absorptiometry(DXA)can be adopted to measure bone mineral density(BMD)in the hip,spine,legs and the whole body.The muscle and fat mass in the legs and the whole body can be also calculated by DXA body composition analysis.Based on the proposed protocol for backscatter measurements by UBBD,ultrasonic backscatter signals can be measured in vivo,deriving three backscatter parameters[apparent integral backscatter(AIB),backscatter signal peak amplitude(BSPA)and the corresponding arrival time(BSPT)].AIB may provide important diagnostic information about bone properties.BSPA and BSPT may be important indicators of muscle and fat properties.The standardized backscatter measurement protocol of the UBBD instrument may have the potential to evaluate musculoskeletal characteristics,providing help for promoting the application of the backscatter technique in the clinical diagnosis of musculoskeletal disorders(MSDs),such as osteoporosis and muscular atrophy.展开更多
A"once-in-a-millennium"super rainstorm battered Zhengzhou,central China,from 07/17/2021 to 07/22/2021(named"7.20"Zhengzhou rainstorm).It killed 398 people and caused billions of dollars in damage.A...A"once-in-a-millennium"super rainstorm battered Zhengzhou,central China,from 07/17/2021 to 07/22/2021(named"7.20"Zhengzhou rainstorm).It killed 398 people and caused billions of dollars in damage.A pressing question is whether rainstorms of this intensity can be effectively documented by geological archives to understand better their historical variabilities beyond the range of meteorological data.Here,four land snail shells were collected from Zhengzhou,and weekly to daily resolved snail shellδ^(18)O records from June to September of 2021 were obtained by gas-source mass spectrometry and secondary ion mass spectrometry.The daily resolved records show a dramatic negative shift between 06/18/2021 and 09/18/2021,which has been attributed to the"7.20"Zhengzhou rainstorm.Moreover,the measured amplitude of this shift is consistent with the theoretical value estimated from the flux balance model and instrumental data for the"7.20"Zhengzhou rainstorm.Our results suggest that the ultra-high resolutionδ^(18)O of land snail shells have the potential to reconstruct local synoptic scale rainstorms quantitatively,and thus fossil snail shells in sedimentary strata can be valuable material for investigating the historical variability of local rainstorms under different climate backgrounds.展开更多
基金funded by Qingyang Science and Technology Support Project(KT2019-03)。
文摘A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.
基金financial support from the Science Foundation for Outstanding Young Scholars of Shandong Province (No. 2022HWYQ- 009)the Natural Science Foundation of Shandong Province (No. ZR2021QB201, No. YDZX2021001)the Qilu Young Scholars Program of Shandong University。
文摘Although a few pristine metal-organic frameworks(MOFs) of graphene analogue topology exhibit high intrinsic electrical conductivity, their use in lithium-ion batteries(LIBs) is still hampered by unfavorable Li+adsorption energy(ΔEa). In this paper, an electroconductive ferrocene-based MOF@MXene heterostructure is built to provide stable anodes for Li+storage. Charge density difference and planar average potential charge density show substantial redistribution of charges at the interfaces, transferring from MXene to MOF layers. Moreover, density functional theory(DFT) calculations reveal that the interaction between MXene and MOF significantly increases the ΔEa. As a result, the heterostructure anode exhibits high capacities and outstanding cycling stability with a capacity retention of 80% after 5000 cycles at 5 A g^(-1), outperforming mono-component MXene and MOF. Furthermore, the heterostructure anode is built into a full cell with a commercial NCM 532 cathode, delivering a high energy density of 611 Wh kg^(-1)and power density of 7600 W kg^(-1). The developed conductive MOF@MXene heterogeneity for improved LIB offers valuable insights into the design of advanced electrode materials for energy storage.
基金supported by the National Natural Science Foundation of China under project 52007047the Outstanding Youth Innovation Project funded by State Key Laboratory of Reliability and Intelligence of Electrical Equipment EERI_OY2021005。
文摘Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for high speed operation. However, because of its complex irregular structure, the manufacturing process using silicon sheets is complicated. Soft magnetic composite material(SMC) is manufactured by powder metallurgy technology, which can produce various shapes of stator core structures, so it is easier to produce various irregular shapes of the stator core. However, the raw SMC material is relatively expensive, and the mechanical strength of SMC is weak. In this paper, a PMCPM with hybrid cores is proposed. With the adoption of hybrid silicon sheet-SMC cores and amorphous alloy-SMC cores, the torque ability of PMCPM can be improved greatly and it can have higher efficiency for more wide operation frequency. Meanwhile, its mechanical strength has been improved and it can be designed for high torque direct drive applications as it is a modular machine. Furthermore, three methods are proposed to reduce the additional eddy current loss which resulted from the employment of hybrid cores in PMCPM.
基金supported by the National Natural Science Foundation of China under project 52007047in part by the Outstanding Youth Innovation Project funded by State Key Laboratory of Reliability and Intelligence of Electrical Equipment EERI_OY2021005,and EERI_KF2021014。
文摘Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current loss,and simple manufacturing process.The permanent magnet claw pole machine(PMCPM)with SMC cores is a good case that the SMC to be adopted for developing 3D flux electrical machines.In this paper,a novel axial-radial flux permanent magnet claw pole machine(ARPMCPM)with SMC cores and ferrite magnets is proposed.Compared with the traditional PMCPM,the proposed ARPMCPM is designed with only one spoke PM rotor and its whole structure is quite compact.For the performance prediction,the 3D finite element method(FEM)is used.Meanwhile,for the performance evaluation,a previously developed axial flux claw pole permanent magnet machine(AFCPM)is employed as the benchmark machine and all these machines are optimized by using the combined multilevel robust Taguchi method.It can be seen that the proposed ARPMCPM is with higher torque/weight density and operation efficiency.
基金supported by the National Key R&D Program of China(No.2017YFC0907900,No.2017YFC0907901,No.2017YFC1308700 and No.2017YFC1308705)National Natural Science Foundation of China(No.81773521)。
文摘Objective:Population-level economic burden is essential for prioritizing healthcare resources and healthcare budget making in the future.However,little is known about the economic burden of lung cancer in China.Methods:A prevalence-based approach was adopted to estimate the economic burden of lung cancer,including direct expenditure(medical and non-medical)and indirect cost(disability and premature death).Data on direct expenditure and work-loss days per patient in each year post-diagnosis were obtained from two primary surveys.Other parameters were obtained from literatures and official reports.Projections were conducted based on varying parameters.All expenditure data were reported in United States dollars(USD)using 2017 value(exchange rate:1 USD=6.760 CNY),with the discount rate of 3%.Results:The total economic burden of lung cancer was estimated to be 25,069 million USD in China in 2017(0.121%of gross domestic productivity,GDP).The estimated direct expenditure was 11,098 million USD,up to1.43%of total healthcare expenditure for China,covering 10,303 million USD and 795 million USD for medical and non-medical expenditure,respectively.The estimated indirect cost was 13,971 million,including 1,517 million USD due to disability and 12,454 million USD due to premature death.Under current assumptions,the projected total economic burden would increase to 30.1 billion USD,40.4 billion USD,and 53.4 billion USD in 2020,2025,and 2030,accounting for 0.121%,0.131%,and 0.146%of China's GDP,respectively.However,if China meets the United Nation sustainable development goal of reducing premature death from non-communicable diseases by one-third by 2030,the total economic burden in 2030 would be 31.9 billion USD,0.087%of China's GDP.Conclusions:The economic burden of lung cancer in China in 2017 is substantial and more likely to increase significantly in the future.Policy makers need to take urgent actions in budget making for health systems.The economic burden could be alleviated by reducing the disease burden of lung cancer via effective control and prevention actions.
基金co-supported by the National Natural Science Foundation of China (No. 81773521)CAMS Innovation Fund for Medical Sciences (No. 2017-I2M-1006, No. 2016-12M-2-004)+4 种基金the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences (No. 2018RC330001)the National Key Projects of Research and Development of China (No. 2018 YFC1315000)China Scholarship Council (No. 201908110180)the Sanming Project of Medicine in Shenzhen (No. SZSM201911015)the Cancer Screening Program in Urban China funded by National Health Commission of People’s Republic of China
文摘Objective: Colorectal cancer(CRC) causes a substantial burden of disease in China and the evidence of economic burden triggered is fundamental for priority setting. The aim of this survey was to quantify medical expenditures and the time trends for CRC diagnosis and treatment in China.Methods: From 2012 to 2014, a hospital-based multicenter retrospective survey was conducted in 13 provinces across China. For each eligible CRC patient diagnosed from 2002 to 2011, clinical information and expenditure data were extracted using a uniform questionnaire. All expenditure data were reported in Chinese Yuan(CNY)using 2011 values.Results: Of the 14,536 CRC patients included, the average age at diagnosis was 58.2 years and 15.8% were stageI cases. The average medical expenditure per patient was estimated at 37,902 CNY [95 % confidence interval(95%CI): 37,282-38,522], and the annual average increase rate was 9.2% from 2002 to 2011(P for trend <0.001), with a cumulative increase of 2.4 times(from 23,275 CNY to 56,010 CNY). The expenditure per patient in stages Ⅰ, Ⅱ, Ⅲ and Ⅳ were 31,698 CNY, 37,067 CNY, 38,918 CNY and 42,614 CNY, respectively(P<0.001). Expenditure significantly differed within various subgroups. Expenses for drugs contributed the largest proportion(52.6%).Conclusions: These conservative estimates illustrated that medical expenditures for CRC diagnosis and treatment in tertiary hospitals in China were substantial and increased rapidly over the 10 years, with drugs continually being the main expense by 2011. Relatively, medical expenditures are lower for CRC in the earlier stages. These findings will facilitate the economic evaluation of CRC prevention and control in China.
基金This study was supported by the State Key Projects Specialized on Infectious Diseases(No.2O17ZX1O2O12O1-008-002,No.2O17ZX1O2O12O1-OO6-OO3)Sanming Project of Medicine in Shenzhen(No.SZSM201911015)+2 种基金the National Natural Science Foundation of China(No.81974492,No.81773521)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2019-I2M-2-004)the Natural Science Foundation of Guangdong Province(No.2020A151501478).
文摘Objective:The number of liver cancer patients in China accounts for more than half of the world.However,China currently lacks national,multicenter economic burden data,and meanwhile,measuring the differences among different subgroups will be informative to formulate corresponding policies in liver cancer control.Thus,the aim of the study was to measure the economic burden of liver cancer by various subgroups.Methods:A hospital-based,multicenter and cross-sectional survey was conducted during 2012・2014,covering 39 hospitals and 21 project sites in 13 provinces across China.The questionnaire covers clinical information,sociology,expenditure,and related variables.All expenditure data were reported in Chinese Yuan(CNY)using 2014 values.Results:A total of 2,223 liver cancer patients were enrolled,of whom 59.61%were late-stage cases(III-IV),and 53.8%were hepatocellular carcinoma.The average total expenditure per liver cancer patient was estimated as 53,220 CNY,including 48,612 CNY of medical expenditures(91.3%)and 4,608 CNY of non-medical expenditures(8.7%).The average total expenditures in stage I,H,m and stage IV were 52,817 CNY,50,877 CNY,50,678 CNY and 54,089 CNY(P>0.05),respectively.Non-medical expenditures including additional meals,additional nutrition care,transportation,accommodation and hired informal nursing were 1,453 CNY,839 CNY,946 CNY,679 CNY and 200 CNY,respectively.The one-year out-of-pocket expenditure of a newly diagnosed patient was 24,953 CNY,and 77.2%of the patients suffered an unmanageable financial burden.Multivariate analysis showed that overall expenditure differed in almost all subgroups(P<0.05),except for sex,clinical stage,and pathologic type.Conclusions:There was no difference in treatment expenditure for liver cancer patients at different clinical stages,which suggests that maintaining efforts on treatment efficacy improvement is important but not enough.To fiirtherly reduce the overall economic burden from liver cancer,more effort should be given to primary and secondary prevention strategies.
基金supported by the National Natural Science Foundation of China (11174060, 11327405, and 11504057)the Science and Technology Support Program of Shanghai (13441901900)+1 种基金the PhD Programs Foundation of the Ministry of Education of China (20130071110020)the China Postdoctoral Science Foundation (2015M571490)
文摘Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic (UBBD) instrument and an in vivo application for neonatal bone evaluation are introduced in this study. The UBBD provides several advantages, including noninvasiveness, non- ionizing radiation, portability, and simplicity. In this study, the backscatter signal could be measured within 5 s using the UBBD. Ultrasonic backscatter measurements were performed on 467 neonates (268 males and 199 females) at the left calcaneus. The backscatter signal was measured at a central frequency of 3.5 MHz. The delay (-/-1) and duration (7-2) of the backscatter signal of interest (SOl) were varied, and the apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), zero frequency intercept of apparent backscatter (FIAB), and spectral centroid shift (SCS) were calculated. The results showed that the SOl selection had a direct influence on cancellous bone evaluation. The AIB and FIAB were positively correlated with the gestational age (|R| up to 0.45, P 〈 0.001) when -/-1 was short (〈 8 μS), while negative correlations (|R| up to 0.56, P 〈 0.001) were commonly observed for T1 〉 10 IJS. Moderate positive correlations (IRI up to 0.45, P 〈 0.001) were observed for FSAB and SCS with gestational age when 71 was long (〉 10 μs). The 7-2 mainly introduced fluctuations in the observed correlation coefficients. The moderate correlations observed with UBBD demonstrate the feasibility of using the backscatter signal to evaluate neonatal bone status. This study also proposes an explicit standard for in vivo SOl selection and neonatal cancellous bone assessment.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874289,11827808,11504057,11525416,and 81601504)the Fundamental Research Funds for the Central Universities
文摘The goal of this study is to analyze the statistics of the backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone characterization. Ultrasonic backscatter measurements were performed on 24 bovine cancellous bone specimens in vitro and the backscatter signals were compensated for the frequency-dependent attenuation prior to the envelope detection. The statistics of the backscatter envelope were modeled using the Nakagami distribution. Our results reveal that the backscatter envelope mainly followed pre-Rayleigh distributions, and the deviations of the backscatter envelope from Rayleigh distribution decreased with increasing bone density. The Nakagami shape parameter(i.e., m) was significantly correlated with bone densities(R = 0.78–0.81, p < 0.001) and trabecular microstructures(|R| = 0.46–0.78, p < 0.05). The scale parameter(i.e.,?) and signal-to-noise ratio(SNR) also yielded significant correlations with bone density and structural features. Multiple linear regressions showed that bone volume fraction(BV/TV) was the main predictor of the Nakagami parameters,and microstructure produced significantly independent contribution to the prediction of Nakagami distribution parameters,explaining an additional 10.2% of the variance at most. The in vitro study showed that statistical parameters derived with Nakagami model might be useful for cancellous bone characterization, and statistical analysis has potential for ultrasonic backscatter bone evaluation.
基金the National Natural Science Foundation of China under Project 52007047,in part by the National Natural Science Foundation of China under Project 51877065,and in part by Natural Science Foundation of Hebei Province under Project E2019202220.
文摘As there is no need of permanent magnet(PM)material and only silicon steel sheet required on the rotor,synchronous reluctance machine(SynRM)can be used for many applications and draws a great research interest.For the SynRM,the torque ripple is a big issue and a great of work could been done on reducing it.In this paper,asymmetrical magnetic flux barriers in the SynRM rotor were studied comprehensively,including angle and width of each layer and each side of the magnetic barrier.The SynRMb with asymmetrical and parallel magnetic flux barrier was found as the best way to design SynRM based on the multi-objective design optimization method.Moreover,each parameter was studied to show the design rule of the asymmetrical magnetic flux barrier.As the average torque will be reduced with the asymmetrical barrier is used,the grain-oriented silicon steel is used on stator teeth of the SynRMb(SynRMbG)was proposed and studied.The analysis results show that the proposed new method can make the SynRM have better performance.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11827808,11874289,and 11804056)the National Science Fund for Distinguished Young Scholars of China(Grant No.11525416)+3 种基金Shanghai Municipal Science and Technology Major Project,China(Grant No.2017SHZDZX01)Shanghai Talent Development Fund(Grant No.2018112)State Key Laboratory of ASIC and System Project(Grant No.2018MS004)China Postdoctoral Science Foundation(Grant No.2019M661334)。
文摘The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalities to give accurate ultrasound images for irregular bone boundaries and microstructures using uniform sound velocity assumption rather than getting a prior knowledge of sound speed. To overcome these limitations, this paper proposed a frequency-domain fullwaveform inversion(FDFWI) algorithm for bone quantitative imaging utilizing ultrasonic computed tomography(USCT).The forward model was calculated in the frequency domain by solving the full-wave equation. The inverse problem was solved iteratively from low to high discrete frequency components via minimizing a cost function between the modeled and measured data. A quasi-Newton method called the limited-memory Broyden–Fletcher–Goldfarb–Shanno algorithm(L-BFGS) was utilized in the optimization process. Then, bone images were obtained based on the estimation of the velocity and density. The performance of the proposed method was verified by numerical examples, from tubular bone phantom to single distal fibula model, and finally with a distal tibia-fibula pair model. Compared with the high-resolution peripheral quantitative computed tomography(HR-p QCT), the proposed FDFWI can also clearly and accurately presented the wavelength scaled pores and trabeculae in bone images. The results proved that the FDFWI is capable of reconstructing high-resolution ultrasound bone images with sub-millimeter resolution. The parametric bone images may have the potential for the diagnosis of bone disease.
文摘In agriculture production,plant health is threatened by pathogens parasitic on seeds;hence,it is necessary to disinfect harvested seeds before germination.In this study,a technique of gliding arc plasma treatment was proposed and investigated.The experiment was conducted to treat Astragalus membranaceus(A.membranaceus)seeds that were artificially infected with Fusarium oxysporum(F.oxysporum).The plasma treatment duration varied from 30 s to 270 s.Direct and indirect treatments were compared to evaluate the inactivation efficiency of the F.oxysporum spores on the surface of seeds.The results indicated that the direct treatment behaved significantly better in disinfection than the indirect way.Meanwhile,experiments of the quantitative assessment of seed germination were also conducted,including the germination rate,the germination potential,and the germination index.The results showed that the inactivation efficiency increased as the plasma treatment time was extended.When the treatment time was90 s,the inactivation efficiency reached more than 98%.The plasma treatment of 270 s had a complete devitalization of F.oxysporum spores on the surface of the seeds.After the treatment of 30 s and 90 s,the seed germination parameters improved significantly.This study verified the inactivation efficacy of gliding arc discharge plasma under atmospheric pressure.The technique of gliding arc treatment shows advantages of energy saving and adaptation and has the potential to be utilized in industry.
基金supported by the National Natural Science Foundation of China(grant numbers 81430011,81470711,and 81670978)the Brilliant Young Investigator Award,Sichuan University(grant number 2015SCU04A16)
文摘Postmenopausal osteoporosis (PMO) is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidity and serious complications of PMO, many efforts have been devoted to its prophylaxis and treatment. The intestinal microbiota is the complex community of microorganisms colonizing the gastrointestinal tract. Probiotics, which are dietary or medical supplements consisting of beneficial intestinal bacteria, work in concert with endogenous intestinal microorganisms to maintain host health. Recent studies have revealed that bone loss in PMO is closely related to host immunity, which is influenced by the intestinal microbiota. The curative effects of probiotics on metabolic bone diseases have also been demonstrated. The effects of the intestinal microbiota on bone metabolism suggest a promising target for PMO management. This review seeks to summarize the critical effects of the intestinal microbiota and probiotics on PMO, with a focus on the molecular mechanisms underlying the pathogenic relationship between bacteria and host, and to define the possible treatment options.
文摘In recent years,with high-speed development of economy and society,and fast propulsion of industrialization and urbanization process in the development zone,average annual land demand in the development zone also quickly enlarges,and the contradiction between high-speed growth of economy and shortage of land resources is apparent increasingly. Meanwhile,to guarantee crop safety and stick to 0. 12 billion hm2of farmland red line as a rigid constraint which could not be exceeded,the supply-demand contradiction of industrial land is more and more prominent. With industrial land scale continues to enlarge,land resources become more and more scarce,but there exists the phenomenon of low-efficiency land use and even idle. For land use characteristics of the development zone,taking Hefei City Economic and Technological Development Zone as an example,the countermeasures of perfecting industrial land transfer mechanism in the development zone are proposed.
基金This work was supported in part by the National Natural Science Foundation of China under project 51877065Hebei Province Education Department Youth Talent Leading Project under grant BJ2018037in part by the State Key Laboratory of Reliability and Intelligence of Electrical Equipment under grant EERIKF2018005.
文摘The performance of traditional flux switching permanent magnet tubular machine(FSPMTM)are improved by using new material and structure in this paper.The existing silicon steel sheet making for all mover cores or part of stator cores are replaced by soft magnetic composite(SMC)cores,and the lamination direction of the silicon steel sheet in stator cores have be changed.The eddy current loss of the machine with hybrid cores will be reduced greatly as the magnetic flux will not pass through the silicon steel sheet vertically.In order to reduce the influence of end effect,the unequal stator width design method is proposed.With the new design,the symmetry of the permanent magnet flux linkage has been improved greatly and the cogging force caused by the end effect has been reduced.Both 2-D and 3-D finite element methods(FEM)are applied for the quantitative analysis.
基金This work was supported in part by the National Natural Science Foundation of China under project 51877065Hebei Province Education Department Youth Talent Leading Project under grant BJ2018037.
文摘This paper proposes a new rotary flux switching transverse flux machine with the ability of linear motion(FSTFMaLM),in which both the stator and the rotor cores are made by using soft magnetic composite(SMC)materials.With the special design pattern,for the rotary motion model,the proposed machine can combine both the advantages of the flux switching permanent magnet machine(FSPMM)and the transverse flux machine(TFM).It can output with relatively high torque density,and as there is no windings or the magnets on the rotor cores,the proposed machine can operate in the high speed region to improve the output power.With the adoption of the SMC materials,the manufacturing of this machine can be quite easy.By stacking the rotor core together and prolong it with the determined length in the axial direction,in addition with the special control algorithm,the proposed machine can have the ability of the linear motion.In this paper,the operation principle of this machine has been explained and the design methods are also presented.To seek the better performance,the main dimension of the machine is optimized,and for the performance evaluation,the finite element method(FEM)is adopted.The proposed machine can be used for the electric driving systems,robotic systems or other applications where the linear motion ability is required.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12104096,12004079,82127803,11827808,and 61871263)the Shanghai Science and Technology Innovation Plan(Grant Nos.20S31901300 and 19441903400)+1 种基金the Shanghai Rising-Star Program(Grant No.21QC1400100)the China Postdoctoral Science Foundation(Grant No.2021M690709)。
文摘The ultrasonic backscatter(UB)has the advantage of non-invasively obtaining bone density and structure,expected to be an assessment tool for early diagnosis osteoporosis.All former UB measurements were based on exciting a short single-pulse and analyzing the ultrasonic signals backscattered in bone.This study aims to examine amplitude modulation(AM)ultrasonic excitation with UB measurements for predicting bone characteristics.The AM multiple lengths excitation and backscatter measurement(AM-UB)functions were integrated into a portable ultrasonic instrument for bone characterization.The apparent integrated backscatter coefficient in the AM excitation(AIB_(AM))was evaluated on the AM-UB instrumentation.The correlation coefficients of the AIB_(AM) estimating volume fraction(BV/TV),structure model index(SMI),and bone mineral density(BMD)were then analyzed.Significant correlations(|R|=0.82-0.93,p<0.05)were observed between the AIB_(AM),BV/TV,SMI,and BMD.By growing the AM excitation length,the AIB_(AM) values exhibit more stability both in 1.0-MHz and 3.5-MHz measurements.The recommendations in AM-UB measurement were that the avoided length(T1)should be lower than AM excitation length,and the analysis length(T2)should be enough long but not more than AM excitation length.The authors conducted an AM-UB measurement for cancellous bone characterization.Increasing the AM excitation length could substantially enhance AIB_(AM) values stability with varying analyzed signals.The study suggests the portable AM-UB instrument with the integration of real-time analytics software that might provide a potential tool for osteoporosis early screening.
文摘In medical images, exist often a lot of noise, the noise will seriously affect the accuracy of the segmentation results. The traditional standard fuzzy c-means(FCM) algorithm in image segmentation do not taken into account the relationship the adjacent pixels, which leads to the standard fuzzy c-means(FCM) algorithm is very sensitive to noise in the image. Proposed improvedfuzzy c-means(FCM) algorithm, taking both the local and non-local information into the standard fuzzy c-means(FCM) clustering algorithm. The ex-periment results can show that the improved algorithm can achieve better effect than other methods of brain tissue segmentation.
基金Shanghai Municipal Science and Technology Major Project(2017SHZDZX01)the National Natural Science Foundation of China(12034005,12122403,11827808,11874289)+3 种基金the China Postdoctoral Science Foundation(2021M690709)the Shanghai Science and Technology Innovation Plan(20S31901300)the Shanghai Rising-Star Program(21QC1400100)the China Scholarship Council(202106100122).
文摘This study aims to introduce the protocol for ultrasonic backscatter measurements of musculoskeletal properties based on a novel ultrasonic backscatter bone diagnostic(UBBD)instrument.Dual-energy X-ray absorptiometry(DXA)can be adopted to measure bone mineral density(BMD)in the hip,spine,legs and the whole body.The muscle and fat mass in the legs and the whole body can be also calculated by DXA body composition analysis.Based on the proposed protocol for backscatter measurements by UBBD,ultrasonic backscatter signals can be measured in vivo,deriving three backscatter parameters[apparent integral backscatter(AIB),backscatter signal peak amplitude(BSPA)and the corresponding arrival time(BSPT)].AIB may provide important diagnostic information about bone properties.BSPA and BSPT may be important indicators of muscle and fat properties.The standardized backscatter measurement protocol of the UBBD instrument may have the potential to evaluate musculoskeletal characteristics,providing help for promoting the application of the backscatter technique in the clinical diagnosis of musculoskeletal disorders(MSDs),such as osteoporosis and muscular atrophy.
基金supported by the National Natural Science Foundation of China(42221003,4202530442103084)the Research Projects from the Chinese Academy of Sciences(XDB40000000)+1 种基金the Science and Technology Innovation Project of Laoshan Laboratory(LSKJ202203300)the CAS Youth Interdisciplinary Team。
文摘A"once-in-a-millennium"super rainstorm battered Zhengzhou,central China,from 07/17/2021 to 07/22/2021(named"7.20"Zhengzhou rainstorm).It killed 398 people and caused billions of dollars in damage.A pressing question is whether rainstorms of this intensity can be effectively documented by geological archives to understand better their historical variabilities beyond the range of meteorological data.Here,four land snail shells were collected from Zhengzhou,and weekly to daily resolved snail shellδ^(18)O records from June to September of 2021 were obtained by gas-source mass spectrometry and secondary ion mass spectrometry.The daily resolved records show a dramatic negative shift between 06/18/2021 and 09/18/2021,which has been attributed to the"7.20"Zhengzhou rainstorm.Moreover,the measured amplitude of this shift is consistent with the theoretical value estimated from the flux balance model and instrumental data for the"7.20"Zhengzhou rainstorm.Our results suggest that the ultra-high resolutionδ^(18)O of land snail shells have the potential to reconstruct local synoptic scale rainstorms quantitatively,and thus fossil snail shells in sedimentary strata can be valuable material for investigating the historical variability of local rainstorms under different climate backgrounds.