With the growing application of intelligent robots in service,manufacturing,and medical fields,efficient and natural interaction between humans and robots has become key to improving collaboration efficiency and user ...With the growing application of intelligent robots in service,manufacturing,and medical fields,efficient and natural interaction between humans and robots has become key to improving collaboration efficiency and user experience.Gesture recognition,as an intuitive and contactless interaction method,can overcome the limitations of traditional interfaces and enable real-time control and feedback of robot movements and behaviors.This study first reviews mainstream gesture recognition algorithms and their application on different sensing platforms(RGB cameras,depth cameras,and inertial measurement units).It then proposes a gesture recognition method based on multimodal feature fusion and a lightweight deep neural network that balances recognition accuracy with computational efficiency.At system level,a modular human-robot interaction architecture is constructed,comprising perception,decision,and execution layers,and gesture commands are transmitted and mapped to robot actions in real time via the ROS communication protocol.Through multiple comparative experiments on public gesture datasets and a self-collected dataset,the proposed method’s superiority is validated in terms of accuracy,response latency,and system robustness,while user-experience tests assess the interface’s usability.The results provide a reliable technical foundation for robot collaboration and service in complex scenarios,offering broad prospects for practical application and deployment.展开更多
The space environment, particularly highly reactive atomic oxygen(AO), often causes performance degradation and accelerated wear of solid-lubricating materials used in aerospace applications. In this study, an in situ...The space environment, particularly highly reactive atomic oxygen(AO), often causes performance degradation and accelerated wear of solid-lubricating materials used in aerospace applications. In this study, an in situ oxygen-passivated WS_(2) lubricating film(W–S–Ti–O composite film) was deposited to withstand AO irradiation. The structural and tribological evolution of the film was examined after a six-month space exposure experiment conducted outside the Chinese Space Station. The results show that in situ oxygen passivation of sulfur vacancies in the WS_(2) film promoted the formation of a dominant WS_(x)O_(y) phase within the W–S–Ti–O composite film. This phase effectively suppressed excessive WO_(3) formation during prolonged AO exposure while maintaining a low friction coefficient. After space exposure, the film exhibited a low friction coefficient and a wear life exceeding 4.5 × 10^(5) cycles. This performance is attributed to two main factors:(1) the presence of friction-induced spherical WO_(3) nanoparticles(approximately 11 nm) embedded in the transfer film, which promoted a transition from pure sliding to a mixed rolling–sliding regime;and(2) the retention of oriented WS_(2)(002) crystalline layers in the tribofilm, which mitigated the plowing effect of nanoparticles and prevented a significant increase in the wear rate.展开更多
To investigate the inhibitory effects of Ginsenoside Rbl （GRbl） on apoptosis caused by Herpes Simplex Virus-1 （HSV-1） in Human Glioma Cells （U251）, U251 cells were infected by HSV-1 at a multiplicity of infectio...To investigate the inhibitory effects of Ginsenoside Rbl （GRbl） on apoptosis caused by Herpes Simplex Virus-1 （HSV-1） in Human Glioma Cells （U251）, U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRbl, GRbl＋HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRbl on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb 1 and 400 μg/mL GRbl＋HSV-1 groups, MTT values were higher than control group at all times （P〈0.05）. Moreover, the apoptosis rate in the 400 μg/mL GRbl＋HSV-1 group was lower than the HSV-1 group （P〈0. 05）. These results confirmed that, at appropriate concentrations, GRbl could inhibit nerve cell apoptosis in HSV-1 infections.展开更多
Objective Metabotropic glutamate receptor 5 （mGluR5） is concentrated in zones of active neurogenesis in the prenatal and postnatal rodent brain and plays an important role in the regulation of neurogenesis. However,...Objective Metabotropic glutamate receptor 5 （mGluR5） is concentrated in zones of active neurogenesis in the prenatal and postnatal rodent brain and plays an important role in the regulation of neurogenesis. However, little is known about mGluR5 in the prenatal human brain. Here, we aimed to explore the expression pattern and cellular distribution of mGluR5 in human fetal hippocampus. Methods Thirty-four human fetuses were divided into four groups according to gestational age： 9-11, 14-16, 22-24 and 32-36 weeks. The hippocampus was dissected out and prepared. The protein and mRNA expression of mGluR5 were evaluated by Western blot and immunohistochemistry or real-time PCR. The cellular distribution of mGluR5 was observed with double-labeling immunofluorescence. Results Both mGluR5 mRNA and protein were detected in the prenatal human hippocampus by real-time PCR and immunoblotting, and the expression levels increased gradually over time. The immunohistochemistry results were consistent with immunoblotting and showed that mGluR5 immunoreactivity was mainly present in the inner marginal zone （IMZ）, hippocampal plate （HP） and ventricular zone （VZ）. The double-labeling immunoftuorescence showed that mGluR5 was present in neural stem cells （nestin-positive）, neuroblasts （DCX-positive） and mature neurons （NeuN-positive）, but not in typical astrocytes （GFAP- positive）. The cells co-expressing mGluR5 and nestin were mainly located in the IMZ, HP and subplate at 11 weeks, all layers at 16 weeks, and CA 1 at 24 weeks. As development proceeded, the number of mGluR5/nestin double-positive cells decreased gradually so that there were only a handful of double-labeled cells at 32 weeks. However, mGluR5/DCX double-positive cells were only found in the HP, IZ and IMZ at 11 weeks. Conclusion The pattern ofmGluR5 expression by neural stern/progenitor cells, neuroblasts and neurons provides important anatomical evidence for the role of mGluR5 in the regulation of human hippocampal development.展开更多
Planning for water quality management is important for facilitating sustainable socio-economic development;however, the planning is also complicated by a variety of uncertainties and nonlinearities. In this study, an ...Planning for water quality management is important for facilitating sustainable socio-economic development;however, the planning is also complicated by a variety of uncertainties and nonlinearities. In this study, an interval-parameter fuzzy robust nonlinear programming (IFRNP) model was developed for water quality management to deal with such difficulties. The developed model incorporated interval nonlinear programming (INP) and fuzzy robust programming (FRP) methods within a general optimization framework. The developed IFRNP model not only could explicitly deal with uncertainties represented as discrete interval numbers and fuzzy membership functions, but also was able to deal with nonlinearities in the objective function.展开更多
Due to the arid and sandy surface of the Taklimakan Desert(TD)in China,the turbulence structure and vertical distribution of ozone exhibit unique and complex characteristics.However,few studies have focused on these i...Due to the arid and sandy surface of the Taklimakan Desert(TD)in China,the turbulence structure and vertical distribution of ozone exhibit unique and complex characteristics.However,few studies have focused on these issues.To reveal the variation characteristics of summertime atmospheric turbulence and ozone concentration over the TD,we conducted joint detection experiments in July 2016 and July 2021 at Tazhong in the hinterland of the TD using an eddy covariance detection system,a GPS(Global Positioning System)sounding system,and a meteorological gradient tower.Using methods such as statistical analysis,nonlinear fitting,and Fast Fourier Transform,this study analyzed and processed parameters including temperature,relative humidity,wind speed,turbulence parameters,turbulence spectra,and ozone concentration.The high average temperature is accompanied by low relative humidity over the TD,showing a negative correlation between the two.The temperature of the 10.0-cm-deep sand layer lags the near-surface air temperature by nearly 4 h.From 09:30 to 21:00(Beijing Time),under conditions where the sensible heat flux is positive but stability parameter(z/L,where z is the height and L is the Obukhov length)is negative,the atmosphere is heated by the land surface,with the occurrence of unstable stratification;however,the conditions are the opposite(sensible heat flux is negative and z/L is positive)after 22:00,which are accompanied with the cooling of the surface radiation,occurrence of temperature inversion in the lower atmosphere,and stable stratification.A positive correlation is identified between the diurnal variation of turbulent kinetic energy(TKE)and the atmospheric boundary layer(ABL)height,with significant contributions from both the buoyancy and shear terms during the daytime.Under unstable stratification,the normalized standard deviations of the three-dimensional wind speed,temperature,and humidity conform to the Monin-Obukhov Similarity Theory(MOST).As the stability parameter z/L transitions from strongly unstable to strongly stable,the energy of the dimensionless turbulent velocity spectra gradually decreases and conforms to the -2/3 power law within the inertial subrange.In the hinterland of the TD,the summertime tropospheric ozone concentration remains below approximately 0.70×10^(-6)(volume concentration).Above the troposphere,within the range of 16,500.0-30,000.0 m,a significant increasing trend is identified in the ozone concentration with altitude.At an altitude of 30,000.0 m,the maximum ozone concentration can reach up to 7.50×10^(-6).The research findings provide both theoretical and data foundations for future in-depth studies of turbulent motion and ozone concentration distribution in the TD,as well as in the similar areas around the world.展开更多
Energy burden,the inability to afford sufficient energy sources for basic household needs such as heating,cooling,cooking,and lighting,is one of the major social challenges in the U.S.While limited studies have examin...Energy burden,the inability to afford sufficient energy sources for basic household needs such as heating,cooling,cooking,and lighting,is one of the major social challenges in the U.S.While limited studies have examined these issues separately,to our knowledge,no study has empirically investigated the implication of energy burden for chronic kidney disease(CKD)within the U.S.context.This study aims to examine the association between energy burden and CKD prevalence across 500 U.S.cities by using nationally representative data sets.Utilizing propensity score matching and a random intercept analysis,we found that census tracts with high energy burden were significantly associated with a 0.195 higher chronic kidney prevalence[95%CI:0.144-0.246]compared to those with low energy burden,after adjusting key observed characteristics such as living,housing,and sociodemographic conditions of census tracts.Other risk factors contributing to increased CKD prevalence included older building age,higher percentages of nonwhite populations and older adults,lower educational levels,and lower average household incomes.The findings highlight that energy burden is not merely a financial problem but rather a social determinant of CKD health and a significant risk factor for increased CKD prevalence in U.S.urban areas.Our results indicate that state and local energy assistance programs may serve as important interventions not only for improving kidney health outcomes but also for reducing health disparities in the U.S.展开更多
To get large dissymmetric factor(g_(lum))of organic circularly polarized luminescence(CPL)materials is still a great challenge.Although helical chirality and planar chirality are usual efficient access to enhancement ...To get large dissymmetric factor(g_(lum))of organic circularly polarized luminescence(CPL)materials is still a great challenge.Although helical chirality and planar chirality are usual efficient access to enhancement of CPL,they are not combined together to boost CPL.Here,a new tetraphenylethylene(TPE)tetracycle acid helicate bearing both helical chirality and planar chirality was designed and synthesized.Uniquely,synergy of the helical chirality and planar chirality was used to boost CPL signals both in solution and in helical self-assemblies.In the presence of octadecylamine,the TPE helicate could form helical nanofibers that emitted strong CPL signals with an absolute g_(lum)value up to 0.237.Exceptionally,followed by addition of para-phenylenediamine,the g_(lum)value was successively increased to 0.387 due to formation of bigger helical nanofibers.Compared with that of TPE helicate itself,the CPL signal of the self-assemblies was not only magnified by 104-fold but also inversed,which was very rare result for CPL-active materials.Surprisingly,the interaction of TPE helicate with xylylenediamine even gave a gel,which was transformed into suspension by shaking.Unexpectedly,the suspension showed 40-fold stronger CPL signals than the gel with signal direction inversion each other.Using synergy of the helical chirality and planar chirality to significantly boost CPL intensity provides a new strategy in preparation of organic CPL materials having very large g_(lum)value.展开更多
Zinc leaching residue(ZLR),produced from traditional zinc hydrometallurgy process,is not only a hazardous waste but also a potential valuable solid.The combination of sulfate roasting and water leaching was employed t...Zinc leaching residue(ZLR),produced from traditional zinc hydrometallurgy process,is not only a hazardous waste but also a potential valuable solid.The combination of sulfate roasting and water leaching was employed to recover the valuable metals from ZLR.The ZLR was initially roasted with ferric sulfate at640°C for1h with ferric sulfate/zinc ferrite mole ratio of1.2.In this process,the valuable metals were efficiently transformed into water soluble sulfate,while iron remains as ferric oxide.Thereafter,water leaching was conducted to extract the valuable metals sulfate for recovery.The recovery rates of zinc,manganese,copper,cadmium and iron were92.4%,93.3%,99.3%,91.4%and1.1%,respectively.A leaching toxicity test for ZLR was performed after water leaching.The results indicated that the final residue was effectively detoxified and all of the heavy metal leaching concentrations were under the allowable limit.展开更多
Polypyrrole（PPy） shows a favorable application in the electromagnetic interference（EMI） shielding due to its good electrical conductivity and outstanding air stability.Conducting PPy films with high conductivity a...Polypyrrole（PPy） shows a favorable application in the electromagnetic interference（EMI） shielding due to its good electrical conductivity and outstanding air stability.Conducting PPy films with high conductivity and good adhesion were successfully polymerized on the surface of insulating epoxy resin substrates using chemical polymerization.The factors affecting the properties of PPy films,such as the surface morphology,adhesion between PPy film and substrate,electrical conductivity,EMI shielding effectiveness（SE）,were investigated.The adhesion was improved significantly through a three-step surface pretreatment of epoxy resin substrates including removing impurities,roughening,and surface modification with silane coupling agent.An enhancement in the conductivity of PPy films of about one order of magnitude was achieved by adding dopant in FeCl_3 solution.The higher the conductivity,the better the shielding effectiveness.Taking sodium p-toluenesulfonate doped PPy film as example,EMI SE was in the practically useful range of about 30 dB over a wide frequency range from 30 MHz to 1500 MHz.The PPy film samples were characterized by scanning electron microscopy （SEM）,infrared spectra（IR）,X-ray photoelectron spectroscopy（XPS） and the flange coaxial transmission device.The fourpoint probe method was used to measure conductivity of PPy films.展开更多
AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 ey...AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.展开更多
Currently,little in-depth evidence is known about the application of extracorporeal membrane oxygenation(ECMO)therapy in coronavirus disease 2019(COVID-19)patients.This retrospective multicenter cohort study included ...Currently,little in-depth evidence is known about the application of extracorporeal membrane oxygenation(ECMO)therapy in coronavirus disease 2019(COVID-19)patients.This retrospective multicenter cohort study included patients with COVID-19 at 7 designated hospitals in Wuhan,China.The patients were followed up until June 30,2020.Univariate and multivariate logistic regression analyses were performed to identify the risk factors associated with unsuccessful ECMO weaning.Propensity score matching was used to match patients who received veno-venous ECMO with those who received invasive mechanical ventilation(IMV)-only therapy.Of 88 patients receiving ECMO therapy,27 and 61 patients were and were not successfully weaned from ECMO,respectively.Additionally,15,15,and 65 patients were further weaned from IMV,discharged from hospital,or died during hospitalization,respectively.In the multivariate logistic regression analysis,a lymphocyte count≤0.5×10^(9)/L and D-dimer concentration>4×the upper limit of normal level at ICU admission,a peak PaCO_(2)>60 mmHg at 24 h before ECMO initiation,and no tracheotomy performed during the ICU stay were independently associated with lower odds of ECMO weaning.In the propensity scorematched analysis,a mixed-effect Cox model detected a lower hazard ratio for 120-day all-cause mortality after ICU admission during hospitalization in the ECMO group.The presence of lymphocytopenia,higher D-dimer concentrations at ICU admission and hypercapnia before ECMO initiation could help to identify patients with a poor prognosis.Tracheotomy could facilitate weaning from ECMO.ECMO relative to IMV-only therapy was associated with improved outcomes in critically ill COVID-19 patients.展开更多
文摘With the growing application of intelligent robots in service,manufacturing,and medical fields,efficient and natural interaction between humans and robots has become key to improving collaboration efficiency and user experience.Gesture recognition,as an intuitive and contactless interaction method,can overcome the limitations of traditional interfaces and enable real-time control and feedback of robot movements and behaviors.This study first reviews mainstream gesture recognition algorithms and their application on different sensing platforms(RGB cameras,depth cameras,and inertial measurement units).It then proposes a gesture recognition method based on multimodal feature fusion and a lightweight deep neural network that balances recognition accuracy with computational efficiency.At system level,a modular human-robot interaction architecture is constructed,comprising perception,decision,and execution layers,and gesture commands are transmitted and mapped to robot actions in real time via the ROS communication protocol.Through multiple comparative experiments on public gesture datasets and a self-collected dataset,the proposed method’s superiority is validated in terms of accuracy,response latency,and system robustness,while user-experience tests assess the interface’s usability.The results provide a reliable technical foundation for robot collaboration and service in complex scenarios,offering broad prospects for practical application and deployment.
基金financially supported by the Space Utilization System of China Manned Space Engineering (Grant No.KJZ-YY-WCL05)。
文摘The space environment, particularly highly reactive atomic oxygen(AO), often causes performance degradation and accelerated wear of solid-lubricating materials used in aerospace applications. In this study, an in situ oxygen-passivated WS_(2) lubricating film(W–S–Ti–O composite film) was deposited to withstand AO irradiation. The structural and tribological evolution of the film was examined after a six-month space exposure experiment conducted outside the Chinese Space Station. The results show that in situ oxygen passivation of sulfur vacancies in the WS_(2) film promoted the formation of a dominant WS_(x)O_(y) phase within the W–S–Ti–O composite film. This phase effectively suppressed excessive WO_(3) formation during prolonged AO exposure while maintaining a low friction coefficient. After space exposure, the film exhibited a low friction coefficient and a wear life exceeding 4.5 × 10^(5) cycles. This performance is attributed to two main factors:(1) the presence of friction-induced spherical WO_(3) nanoparticles(approximately 11 nm) embedded in the transfer film, which promoted a transition from pure sliding to a mixed rolling–sliding regime;and(2) the retention of oriented WS_(2)(002) crystalline layers in the tribofilm, which mitigated the plowing effect of nanoparticles and prevented a significant increase in the wear rate.
基金Supported by National Natural Science Foundation of China(Grant No.81070501 and 30770105)Shandong Provincial Outstanding Medical Academic Professional Program
文摘To investigate the inhibitory effects of Ginsenoside Rbl （GRbl） on apoptosis caused by Herpes Simplex Virus-1 （HSV-1） in Human Glioma Cells （U251）, U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRbl, GRbl＋HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRbl on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb 1 and 400 μg/mL GRbl＋HSV-1 groups, MTT values were higher than control group at all times （P〈0.05）. Moreover, the apoptosis rate in the 400 μg/mL GRbl＋HSV-1 group was lower than the HSV-1 group （P〈0. 05）. These results confirmed that, at appropriate concentrations, GRbl could inhibit nerve cell apoptosis in HSV-1 infections.
基金supported by grants from the National Natural Science Foundation of China(81070998)the Youth Fund of the College of Medicine,Xi'an Jiaotong University(YQN0802)the Fundamental Research Funds for the Central Universities (xjj2011022)
文摘Objective Metabotropic glutamate receptor 5 （mGluR5） is concentrated in zones of active neurogenesis in the prenatal and postnatal rodent brain and plays an important role in the regulation of neurogenesis. However, little is known about mGluR5 in the prenatal human brain. Here, we aimed to explore the expression pattern and cellular distribution of mGluR5 in human fetal hippocampus. Methods Thirty-four human fetuses were divided into four groups according to gestational age： 9-11, 14-16, 22-24 and 32-36 weeks. The hippocampus was dissected out and prepared. The protein and mRNA expression of mGluR5 were evaluated by Western blot and immunohistochemistry or real-time PCR. The cellular distribution of mGluR5 was observed with double-labeling immunofluorescence. Results Both mGluR5 mRNA and protein were detected in the prenatal human hippocampus by real-time PCR and immunoblotting, and the expression levels increased gradually over time. The immunohistochemistry results were consistent with immunoblotting and showed that mGluR5 immunoreactivity was mainly present in the inner marginal zone （IMZ）, hippocampal plate （HP） and ventricular zone （VZ）. The double-labeling immunoftuorescence showed that mGluR5 was present in neural stem cells （nestin-positive）, neuroblasts （DCX-positive） and mature neurons （NeuN-positive）, but not in typical astrocytes （GFAP- positive）. The cells co-expressing mGluR5 and nestin were mainly located in the IMZ, HP and subplate at 11 weeks, all layers at 16 weeks, and CA 1 at 24 weeks. As development proceeded, the number of mGluR5/nestin double-positive cells decreased gradually so that there were only a handful of double-labeled cells at 32 weeks. However, mGluR5/DCX double-positive cells were only found in the HP, IZ and IMZ at 11 weeks. Conclusion The pattern ofmGluR5 expression by neural stern/progenitor cells, neuroblasts and neurons provides important anatomical evidence for the role of mGluR5 in the regulation of human hippocampal development.
文摘Planning for water quality management is important for facilitating sustainable socio-economic development;however, the planning is also complicated by a variety of uncertainties and nonlinearities. In this study, an interval-parameter fuzzy robust nonlinear programming (IFRNP) model was developed for water quality management to deal with such difficulties. The developed model incorporated interval nonlinear programming (INP) and fuzzy robust programming (FRP) methods within a general optimization framework. The developed IFRNP model not only could explicitly deal with uncertainties represented as discrete interval numbers and fuzzy membership functions, but also was able to deal with nonlinearities in the objective function.
基金financially supported by"Tianshan Talent"Training Program-Science and Technology Innovation Team(Tianshan Innovation Team)Project(2022TSYCTD0007)the Youth Innovation Team of China Meteorological Administration(CMA2024QN13)+2 种基金the Central Government Guidance Funds for Local Science and Technology Development Program(ZYYD2025ZY21)the S&T Development Fund of Chinese Academy of Meteorological Sciences(2021KJ034)the Xinjiang Science Fund for Distinguished Young Scholars(2022D01E07).
文摘Due to the arid and sandy surface of the Taklimakan Desert(TD)in China,the turbulence structure and vertical distribution of ozone exhibit unique and complex characteristics.However,few studies have focused on these issues.To reveal the variation characteristics of summertime atmospheric turbulence and ozone concentration over the TD,we conducted joint detection experiments in July 2016 and July 2021 at Tazhong in the hinterland of the TD using an eddy covariance detection system,a GPS(Global Positioning System)sounding system,and a meteorological gradient tower.Using methods such as statistical analysis,nonlinear fitting,and Fast Fourier Transform,this study analyzed and processed parameters including temperature,relative humidity,wind speed,turbulence parameters,turbulence spectra,and ozone concentration.The high average temperature is accompanied by low relative humidity over the TD,showing a negative correlation between the two.The temperature of the 10.0-cm-deep sand layer lags the near-surface air temperature by nearly 4 h.From 09:30 to 21:00(Beijing Time),under conditions where the sensible heat flux is positive but stability parameter(z/L,where z is the height and L is the Obukhov length)is negative,the atmosphere is heated by the land surface,with the occurrence of unstable stratification;however,the conditions are the opposite(sensible heat flux is negative and z/L is positive)after 22:00,which are accompanied with the cooling of the surface radiation,occurrence of temperature inversion in the lower atmosphere,and stable stratification.A positive correlation is identified between the diurnal variation of turbulent kinetic energy(TKE)and the atmospheric boundary layer(ABL)height,with significant contributions from both the buoyancy and shear terms during the daytime.Under unstable stratification,the normalized standard deviations of the three-dimensional wind speed,temperature,and humidity conform to the Monin-Obukhov Similarity Theory(MOST).As the stability parameter z/L transitions from strongly unstable to strongly stable,the energy of the dimensionless turbulent velocity spectra gradually decreases and conforms to the -2/3 power law within the inertial subrange.In the hinterland of the TD,the summertime tropospheric ozone concentration remains below approximately 0.70×10^(-6)(volume concentration).Above the troposphere,within the range of 16,500.0-30,000.0 m,a significant increasing trend is identified in the ozone concentration with altitude.At an altitude of 30,000.0 m,the maximum ozone concentration can reach up to 7.50×10^(-6).The research findings provide both theoretical and data foundations for future in-depth studies of turbulent motion and ozone concentration distribution in the TD,as well as in the similar areas around the world.
基金supported by the American Heart Association grant(19TPA34830085PI,K.Z.)the Empire Innovation Program of the State University of New York(PI,K.Z.).
文摘Energy burden,the inability to afford sufficient energy sources for basic household needs such as heating,cooling,cooking,and lighting,is one of the major social challenges in the U.S.While limited studies have examined these issues separately,to our knowledge,no study has empirically investigated the implication of energy burden for chronic kidney disease(CKD)within the U.S.context.This study aims to examine the association between energy burden and CKD prevalence across 500 U.S.cities by using nationally representative data sets.Utilizing propensity score matching and a random intercept analysis,we found that census tracts with high energy burden were significantly associated with a 0.195 higher chronic kidney prevalence[95%CI:0.144-0.246]compared to those with low energy burden,after adjusting key observed characteristics such as living,housing,and sociodemographic conditions of census tracts.Other risk factors contributing to increased CKD prevalence included older building age,higher percentages of nonwhite populations and older adults,lower educational levels,and lower average household incomes.The findings highlight that energy burden is not merely a financial problem but rather a social determinant of CKD health and a significant risk factor for increased CKD prevalence in U.S.urban areas.Our results indicate that state and local energy assistance programs may serve as important interventions not only for improving kidney health outcomes but also for reducing health disparities in the U.S.
基金National Natural Science Foundation of China(Nos.22072050,22372066 and 22301090)the Open Research Fund(No.2024JYBKF05)of Key Laboratory of Material Chemistry for Energy Conversion and Storage(HUST)Ministry of Educationthe China Postdoctoral Science Foundation(No.2023M731189)for financial support,and thank the Analytical and Testing Centre at Huazhong University of Science and Technology for measurement.
文摘To get large dissymmetric factor(g_(lum))of organic circularly polarized luminescence(CPL)materials is still a great challenge.Although helical chirality and planar chirality are usual efficient access to enhancement of CPL,they are not combined together to boost CPL.Here,a new tetraphenylethylene(TPE)tetracycle acid helicate bearing both helical chirality and planar chirality was designed and synthesized.Uniquely,synergy of the helical chirality and planar chirality was used to boost CPL signals both in solution and in helical self-assemblies.In the presence of octadecylamine,the TPE helicate could form helical nanofibers that emitted strong CPL signals with an absolute g_(lum)value up to 0.237.Exceptionally,followed by addition of para-phenylenediamine,the g_(lum)value was successively increased to 0.387 due to formation of bigger helical nanofibers.Compared with that of TPE helicate itself,the CPL signal of the self-assemblies was not only magnified by 104-fold but also inversed,which was very rare result for CPL-active materials.Surprisingly,the interaction of TPE helicate with xylylenediamine even gave a gel,which was transformed into suspension by shaking.Unexpectedly,the suspension showed 40-fold stronger CPL signals than the gel with signal direction inversion each other.Using synergy of the helical chirality and planar chirality to significantly boost CPL intensity provides a new strategy in preparation of organic CPL materials having very large g_(lum)value.
基金Project(2014FJ1011)supported by Key Project of Science and Technology of Hunan Province,ChinaProject(201509050)supported by Program for Special Scientific Research Projects of National Public Welfare Industry
文摘Zinc leaching residue(ZLR),produced from traditional zinc hydrometallurgy process,is not only a hazardous waste but also a potential valuable solid.The combination of sulfate roasting and water leaching was employed to recover the valuable metals from ZLR.The ZLR was initially roasted with ferric sulfate at640°C for1h with ferric sulfate/zinc ferrite mole ratio of1.2.In this process,the valuable metals were efficiently transformed into water soluble sulfate,while iron remains as ferric oxide.Thereafter,water leaching was conducted to extract the valuable metals sulfate for recovery.The recovery rates of zinc,manganese,copper,cadmium and iron were92.4%,93.3%,99.3%,91.4%and1.1%,respectively.A leaching toxicity test for ZLR was performed after water leaching.The results indicated that the final residue was effectively detoxified and all of the heavy metal leaching concentrations were under the allowable limit.
基金supported by the National Natural Science Foundation of China(No.60071027)
文摘Polypyrrole（PPy） shows a favorable application in the electromagnetic interference（EMI） shielding due to its good electrical conductivity and outstanding air stability.Conducting PPy films with high conductivity and good adhesion were successfully polymerized on the surface of insulating epoxy resin substrates using chemical polymerization.The factors affecting the properties of PPy films,such as the surface morphology,adhesion between PPy film and substrate,electrical conductivity,EMI shielding effectiveness（SE）,were investigated.The adhesion was improved significantly through a three-step surface pretreatment of epoxy resin substrates including removing impurities,roughening,and surface modification with silane coupling agent.An enhancement in the conductivity of PPy films of about one order of magnitude was achieved by adding dopant in FeCl_3 solution.The higher the conductivity,the better the shielding effectiveness.Taking sodium p-toluenesulfonate doped PPy film as example,EMI SE was in the practically useful range of about 30 dB over a wide frequency range from 30 MHz to 1500 MHz.The PPy film samples were characterized by scanning electron microscopy （SEM）,infrared spectra（IR）,X-ray photoelectron spectroscopy（XPS） and the flange coaxial transmission device.The fourpoint probe method was used to measure conductivity of PPy films.
文摘AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.
基金grants from Emergent Key Projects for COVID-19(No.2020kfyXGYJ091)the National Natural Science Foundation of China(Nos.81800256,81873458,81670050)National Key Research and Development Program of China(No.2019YFC0121600).
文摘Currently,little in-depth evidence is known about the application of extracorporeal membrane oxygenation(ECMO)therapy in coronavirus disease 2019(COVID-19)patients.This retrospective multicenter cohort study included patients with COVID-19 at 7 designated hospitals in Wuhan,China.The patients were followed up until June 30,2020.Univariate and multivariate logistic regression analyses were performed to identify the risk factors associated with unsuccessful ECMO weaning.Propensity score matching was used to match patients who received veno-venous ECMO with those who received invasive mechanical ventilation(IMV)-only therapy.Of 88 patients receiving ECMO therapy,27 and 61 patients were and were not successfully weaned from ECMO,respectively.Additionally,15,15,and 65 patients were further weaned from IMV,discharged from hospital,or died during hospitalization,respectively.In the multivariate logistic regression analysis,a lymphocyte count≤0.5×10^(9)/L and D-dimer concentration>4×the upper limit of normal level at ICU admission,a peak PaCO_(2)>60 mmHg at 24 h before ECMO initiation,and no tracheotomy performed during the ICU stay were independently associated with lower odds of ECMO weaning.In the propensity scorematched analysis,a mixed-effect Cox model detected a lower hazard ratio for 120-day all-cause mortality after ICU admission during hospitalization in the ECMO group.The presence of lymphocytopenia,higher D-dimer concentrations at ICU admission and hypercapnia before ECMO initiation could help to identify patients with a poor prognosis.Tracheotomy could facilitate weaning from ECMO.ECMO relative to IMV-only therapy was associated with improved outcomes in critically ill COVID-19 patients.
