Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morpho...Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morphology and structure to enhance flexibility and effectiveness in wound management.To achieve these,we propose a self-healing hydrogel dressing based on structural color microspheres for wound management.The microsphere comprised a photothermal-responsive inverse opal framework,which was constructed by hyaluronic acid methacryloyl,silk fibroin methacryloyl and black phosphorus quantum dots(BPQDs),and was further re-filled with a dynamic hydrogel.The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran(DEX-CA and DEX-BA).Notably,the composite microspheres can be applied arbitrarily,and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel.Additionally,eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism.Moreover,effective monitoring of the drug release process can be achieved through visual color variations.The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management.These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications.展开更多
Mechanical overloading and aging are two essential factors for osteoarthritis(OA)development.Mitochondria have been identified as a mechano-transducer situated between extracellular mechanical signals and chondrocyte ...Mechanical overloading and aging are two essential factors for osteoarthritis(OA)development.Mitochondria have been identified as a mechano-transducer situated between extracellular mechanical signals and chondrocyte biology,but their roles and the associated mechanisms in mechanical stress-associated chondrocyte senescence and OA have not been elucidated.展开更多
Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has b...Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors.There are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian method.Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)method.With comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak bursts.We further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location templates.Our method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.展开更多
A low-frequency magnetic lightning mapping system(LFM-LMS)was built during the SHAndong Triggered Lightning Experiment(SHATLE),based on continuous measurements of magnetic field radiation from lightning.The hardware a...A low-frequency magnetic lightning mapping system(LFM-LMS)was built during the SHAndong Triggered Lightning Experiment(SHATLE),based on continuous measurements of magnetic field radiation from lightning.The hardware and source-mapping techniques used by the LFM-LMS were introduced;both Monte Carlo simulations and the observation of rocket-triggered lightning examples were employed to examine the location accuracy and detection effectiveness of the LFM-LMS.We estimated that the system’s location accuracy about 100−200 m horizontally and~200 m vertically.A natural intra-cloud lightning flash and a rocket-triggered lightning flash,both with intricate structures and discharging processes,were examined using the three-dimensional mapping results.The progressing path of negative lightning leaders is usually well-defined,and its propagation speed is estimated to be(0.5−1.4)×10^(6)m/s.In summary,the LFM-LMS can reconstruct the three-dimensional morphology of lightning flashes;this technology provides a efficient method for investigating the characteristics of lightning development,as well as the overall electrical strucuture of thunderstorms.展开更多
3D Bioprinting plays an irreplaceable role in bone tissue engineering. Shellac and curcumin are two natural compounds that are widely used in the food and pharmaceutical sectors. In this study, a new composite scaffol...3D Bioprinting plays an irreplaceable role in bone tissue engineering. Shellac and curcumin are two natural compounds that are widely used in the food and pharmaceutical sectors. In this study, a new composite scaffold with good biocompatibility and antibacterial ability was manufactured by adding shellac and curcumin into the traditional bone scaffold through low-temperature three-dimensional printing (LT-3DP), and its impact on the osteoimmune microenvironment was evaluated.展开更多
In this paper, we report the location results for the parent lightning strokes of more than 30 red sprites observed over an asymmetric mesoscale convective system(MCS) on 30 July 2015 in Shandong Province, China, with...In this paper, we report the location results for the parent lightning strokes of more than 30 red sprites observed over an asymmetric mesoscale convective system(MCS) on 30 July 2015 in Shandong Province, China, with a long-baseline lightning location network of very-low-frequency/low-frequency magnetic field sensors. The results show that almost all of these cloud-to-ground(CG) strokes are produced during the mature stage of the MCS, and are predominantly located in the trailing stratiform region, which is similar to analyses of sprite-productive MCSs in North America and Europe. Comparison between the location results for the sprite-producing CG strokes and those provided by the World Wide Lightning Location Network(WWLLN) indicates that the location accuracy of WWLLN for intense CG strokes in Shandong Province is typically within 10 km, which is consistent with the result based on analysis of 2838 sprite-producing CG strokes in the continental United States. Also, we analyze two cases where some minor lightning discharges in the parent flash of sprites can also be located, providing an approach to confine the thundercloud region tapped by the sprite-producing CG strokes.展开更多
Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discuss...Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discussing this technique in catalysis.However,the mechanism on how the deposited materials improve the catalyst stability and tune the reaction selectivity is still unclear.Herein,catalytic systems created via ALD on stepwise preparation and/or modification under self-limiting reaction conditions are summarized.The effects of deposited materials in terms of electronic/geometry modification over the catalytic nanoparticles(NPs)are discussed.These effects explain the mechanism of the catalytic stability improvement and the selectivity modification.The unique properties of ALD for designing new catalytic systems are further investigated for building up photocatalytic reaction nanobowls,tandem catalyst and bi-active-component metallic catalytic systems.展开更多
Increasing evidence shows that adipokines play a vital role in the development of rheumatoid arthritis(RA).Fatty acid-binding protein 4(FABP4),a novel adipokine that regulates inflammation and angiogenesis,has been ex...Increasing evidence shows that adipokines play a vital role in the development of rheumatoid arthritis(RA).Fatty acid-binding protein 4(FABP4),a novel adipokine that regulates inflammation and angiogenesis,has been extensively studied in a variety of organs and diseases.However,the effect of FABP4 on RA remains unclear.Here,we found that FABP4 expression was upregulated in synovial M1-polarized macrophages in RA.The increase in FABP4 promoted synovitis,angiogenesis,and cartilage degradation to exacerbate RA progression in vivo and in vitro,whereas BMS309403(a FABP4 inhibitor)and anagliptin(dipeptidyl peptidase 4 inhibitor)inhibited FABP4 expression in serum and synovial M1-polarized macrophages in mice to alleviate RA progression.Further studies showed that constitutive activation of mammalian target of rapamycin complex 1(mTORC1)by TSC1 deletion specifically in the myeloid lineage regulated FABP4 expression in macrophages to exacerbate RA progression in mice.In contrast,inhibition of mTORC1 by ras homolog enriched in brain(Rheb1)disruption specifically in the myeloid lineage reduced FABP4 expression in macrophages to attenuate RA development in mice.Our findings established an essential role of FABP4 that is secreted by M1-polarized macrophages in synovitis,angiogenesis,and cartilage degradation in RA.BMS309403 and anagliptin inhibited FABP4 expression in synovial M1-polarized macrophages to alleviate RA development.Hence,FABP4 may represent a potential target for RA therapy.展开更多
A versatile wet chemistry method is developed for filling of subnanometer sized metal particles in carbon nanotubes with a diameter smaller than 1.5 nm. As an example, we showed that a confined bi-component Pd-V catal...A versatile wet chemistry method is developed for filling of subnanometer sized metal particles in carbon nanotubes with a diameter smaller than 1.5 nm. As an example, we showed that a confined bi-component Pd-V catalyst exhibit a higher benzene hydroxylation activity compared with that within multi-walled carbon nanotubes.展开更多
The present study established a rat model of cerebral ischemia/reperfusion injury using four-vessel occlusion and found that hippocampal CA1 neuronal morphology was damaged, and that there were reductions in hippocamp...The present study established a rat model of cerebral ischemia/reperfusion injury using four-vessel occlusion and found that hippocampal CA1 neuronal morphology was damaged, and that there were reductions in hippocampal neuron number and DNA-binding activity of cAMP response element binding protein and CCAAT/enhancer binding protein, accompanied by decreased learning and memory ability. These findings indicate that decline of hippocampal cAMP response element binding protein and CCAAT/enhancer binding protein DNA-binding activities may contribute to neuronal injury and learning and memory ability reduction induced by cerebral ischemia/reperfusion injury.展开更多
The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from t...The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from the sprite-producing lightning were measured at five ground stations, making it possible to locate and identify the individual causative lightning discharges for different elements in this dancing sprite event. The results of our analyses indicate that the sprites were produced above the trailing stratiform region of the MCS, and their parent strokes were located mainly in the peripheral area of the stratiform. The lateral offset between sprites and causative strokes ranges from a few km to more than 50 km. In a particularly bright sprite, with a distinct halo feature and streamers descending down to an altitude of approximately 48 km, the sprite current signal identified in the electric sferic, measured at a range of about 1,110 km, peaked at approximately 1 ms after the return stroke.展开更多
A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources obser...A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources observed from the Beijing Lightning Network(BLNET)were used to obtain information about the thunderstorm cells,which are significantly valuable in real-time.The boundaries of thunderstorm cells were obtained through the neighborhood technique.After smoothing,these boundaries were used to track the movement of thunderstorms and then extrapolated to nowcast the lightning approaching in an area of concern.The algorithm can deliver creditable results prior to a thunderstorm arriving at the area of concern,with accuracies of 63%,80%,and 91%for lead times of 30,15,and 5 minutes,respectively.The real-time observations of total lightning appear to be significant for thunderstorm tracking and lightning nowcasting,as total lightning tracking could help to fill the observational gaps in radar reflectivity due to the attenuation by hills or other obstacles.The lightning data used in the algorithm performs well in tracking the active thunderstorm cells associated with lightning activities.展开更多
Leader propagation is a fundamental issue in lightning physics. The propagation characteristics of positive leaders and negative leaders are summarized and compared based on data from high-speed camera and electromagn...Leader propagation is a fundamental issue in lightning physics. The propagation characteristics of positive leaders and negative leaders are summarized and compared based on data from high-speed camera and electromagnetic field in rocket-triggered lightning and tower-initiated lightning discharges; available channel base current data recorded in rocket-triggered lightning are also used. The negative leaders propagate in a stepped fashion accompanied by many branches. The stems ahead of the negative leader tip determine the manner and direction of the leader propagation, and even the branching and winding of the lightning channel. The impulsive current, electromagnetic field, and related optical images suggest that the positive leader may develop in a step-like fashion at its initial stage of triggered lightning. However, the stepping processes of the positive leader are obviously different from those of the negative leader. Tower-initiated lightning revealed that the most conspicuous characteristics of the stepwise positive leader involve the intermittent brush-like corona zone in front of the leader tip and the luminosity enhancement of the channel behind the tip. In rockettriggered lightning flashes, the charge transferred during an individual step for the negative leader was nearly an order greater than for the positive counterpart. The successive streamers ahead of the leader tip are essential for both negative and positive leader propagation, and the stems could be formed from one or more streamers in the previous negative streamer zone with the main leader channel dim. High-resolution observation of tower lightning also revealed a new type of bidirectional recoil leader, with polarity contrary to the traditional one, traversing in negative channels associated with tower-initiated and rocket-triggered lightning.展开更多
Lithium aluminosilicate （LAS） glasses are generally difficult to prepare because of their high melting temperature. In this study, the preparation of LAS glasses was achieved at a relatively low melting temperature....Lithium aluminosilicate （LAS） glasses are generally difficult to prepare because of their high melting temperature. In this study, the preparation of LAS glasses was achieved at a relatively low melting temperature. The batch containing MgO-ZnO-LiEO- Al2O3-SiO2 was melted in a platinum crucible at 1550℃ for 2 h and was then followed by two- or three-step heat treatment processes for nucleation and crystal growth. The characterizations were carried out by differential thermal analysis, X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and UV-Vis-NIR scanning spectrophotometry. The hexagonal stuffed β-eucryptite solid solution crystallized at 840-960℃. Most of the hexagonal β-eucryptite solid solution transformed into the tetragonal β-spodumene solid solution at 1100℃. Almost all the aluminum atoms entered into the tetrahedral sites in the aluminosilicate network of the 6- eucryptite/β-quartz solid solution. All of the Al atoms did not belong to the aluminosilicate network of the β-spodumene solid solution. The glass ceramic with a mean grain size of 10-20 nm is transparent, the transmittance reaches -85% in the visible light wavelength.展开更多
In this work,cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnO_(x)(SY)and GdMnO_(3)(SY)via combustion method and sol-gel method,respec...In this work,cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnO_(x)(SY)and GdMnO_(3)(SY)via combustion method and sol-gel method,respectively.Furthermore,a series of MnO_(x)(SY)-n and GdMnO_(3)(SY)-n(n=0.05,0.10,1.00,4.00,n represents the dilute HNO_(3) concentration)catalysts are fabricated by acid treatment of MnO_(x)(SY)and GdMnO_(3)(SY)samples and catalytic activities of oxygenated VOCs oxidation over all the prepared catalysts are investigated.Catalytic evaluation results show that acid-treated MnO_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples perform the optimum VOCs removal efficiency respectively,which may be attributed to their obvious enhancement of physicochemical properties.In detail,Mn O_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples exhibit the larger specific surface area,bigger amount of surface high-valence metal ions(Mn^(4+),Co^(3+),Ni^(3+)),more abundant adsorbed oxygen species and better low-temperature reducibility,which can play a crucial role in the significant improvement of VOCs oxidation.In situ DRIFTS results imply that the possible main intermediates are-OCO,-COO and-C-O species produced during VOCs oxidation.Possible by-products are further determined via TD/GC-MS analysis.展开更多
Multi-layer microbubble has great potential in enabling the corporation of medical imaging with tumor therapy such as drug and gene delivery of therapeutics or other functional materials in medical applications. Micro...Multi-layer microbubble has great potential in enabling the corporation of medical imaging with tumor therapy such as drug and gene delivery of therapeutics or other functional materials in medical applications. Microfluidic technique has advanced over the last decade and showed great promise in replacing traditional microbubble generating method. In this paper, a multi-layer microbubble structure was produced with the aspect as potentially used for drug loaded microbubble contrast agents.展开更多
[Objectives]To analyze the common compatibility contraindications of breviscapine for injection,and to provide references for clinical rational drug use.[Methods]The pH distribution of the combined drugs in the report...[Objectives]To analyze the common compatibility contraindications of breviscapine for injection,and to provide references for clinical rational drug use.[Methods]The pH distribution of the combined drugs in the report on the compatibility contraindications of breviscapine for injection and was analyzed.[Results]Breviscapine for injection may become turbid or precipitated when mixed with drugs whose pH are lower;it can make the liquid discoloration in a strong alkaline solution.[Conclusions]Breviscapine for injection should not be combined with drugs whose pH are lower,especially drugs with pH lower than 4.2.Breviscapine for injection should not be used with drugs with strong alkaline.It is recommended to use Breviscapine for injection separately.展开更多
Determination of the grouting anchor pullout force is a key step during the design of anchor-pull retaining wall, but it is mostly determined relied on empirical formula at present, and the rationality and the safety ...Determination of the grouting anchor pullout force is a key step during the design of anchor-pull retaining wall, but it is mostly determined relied on empirical formula at present, and the rationality and the safety cannot be effectively guaranteed. Based on the engineering case of the gravity retaining wall of Qinglin Freeway, the model test was designed, and combined with the results of the ABAQUS finite element numerical analysis, it was analyzed that how the anchor axial pulling force distributes. The results showed that the force of the anchor near the wall bolt was large and which far from the wall was small and the ultimate pullout force was proportional to the length, diameter and shear strength. When the end tension of the anchor was small, the top load played a leading role on the anchor tension. This conclusion confirmed the calculation formula of ultimate pullout force was and provided a theoretical basis for anchor-pull retaining wall design and calculation.展开更多
基金supported by the Ruijin Hospital Guangci Introducing Talent Projectfinancial support from National Natural Science Foundation of China(82372145)+4 种基金the Research Fellow(Grant No.353146)Research Project(347897)Solutions for Health Profile(336355)InFLAMES Flagship(337531)grants from Academy of Finlandthe Finland China Food and Health International Pilot Project funded by the Finnish Ministry of Education and Culture.
文摘Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morphology and structure to enhance flexibility and effectiveness in wound management.To achieve these,we propose a self-healing hydrogel dressing based on structural color microspheres for wound management.The microsphere comprised a photothermal-responsive inverse opal framework,which was constructed by hyaluronic acid methacryloyl,silk fibroin methacryloyl and black phosphorus quantum dots(BPQDs),and was further re-filled with a dynamic hydrogel.The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran(DEX-CA and DEX-BA).Notably,the composite microspheres can be applied arbitrarily,and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel.Additionally,eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism.Moreover,effective monitoring of the drug release process can be achieved through visual color variations.The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management.These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications.
基金supported by grants from Natural Science Foundation of China grant No 82172491 (CN)National Natural Science Funds for Excellent Young Scholar No 82322044 (CN)+2 种基金National Key Research and Development Program of China (2022YFC3601902)Youth Talent Support Programme of Guangdong Provincial Association for Science and Technology (SKXRC202308)State-funded postdoctoral researcher program No GZC20231062 (CN)。
文摘Mechanical overloading and aging are two essential factors for osteoarthritis(OA)development.Mitochondria have been identified as a mechano-transducer situated between extracellular mechanical signals and chondrocyte biology,but their roles and the associated mechanisms in mechanical stress-associated chondrocyte senescence and OA have not been elucidated.
基金supported by the National Key R&D Program of China(2021YFA0718500)support from the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(grant Nos.XDA15360102,XDA15360300,XDA15052700 and E02212A02S)+1 种基金the National Natural Science Foundation of China(grant Nos.12173038 and U2038106)the National HEP Data Center(grant No.E029S2S1)。
文摘Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors.There are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian method.Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)method.With comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak bursts.We further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location templates.Our method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.
基金the National Key R&D Program of China(2017YFC1501501)the CAS Project of Stable Support for Youth Team in Basic Research Field(YSRR-018)+3 种基金the Youth Innovation Fund project of the university(WK2080000172)the National Natural Science Foundation of China(41875006,U1938115)the Chinese Meridian Projectthe International Partnership Program of Chinese Academy of Sciences(183311KYSB20200003).
文摘A low-frequency magnetic lightning mapping system(LFM-LMS)was built during the SHAndong Triggered Lightning Experiment(SHATLE),based on continuous measurements of magnetic field radiation from lightning.The hardware and source-mapping techniques used by the LFM-LMS were introduced;both Monte Carlo simulations and the observation of rocket-triggered lightning examples were employed to examine the location accuracy and detection effectiveness of the LFM-LMS.We estimated that the system’s location accuracy about 100−200 m horizontally and~200 m vertically.A natural intra-cloud lightning flash and a rocket-triggered lightning flash,both with intricate structures and discharging processes,were examined using the three-dimensional mapping results.The progressing path of negative lightning leaders is usually well-defined,and its propagation speed is estimated to be(0.5−1.4)×10^(6)m/s.In summary,the LFM-LMS can reconstruct the three-dimensional morphology of lightning flashes;this technology provides a efficient method for investigating the characteristics of lightning development,as well as the overall electrical strucuture of thunderstorms.
文摘3D Bioprinting plays an irreplaceable role in bone tissue engineering. Shellac and curcumin are two natural compounds that are widely used in the food and pharmaceutical sectors. In this study, a new composite scaffold with good biocompatibility and antibacterial ability was manufactured by adding shellac and curcumin into the traditional bone scaffold through low-temperature three-dimensional printing (LT-3DP), and its impact on the osteoimmune microenvironment was evaluated.
基金supported by the National Key Basic Research and Development (973) Program of China (Grant No. 2014CB441405)the Open Research Program of the Key Laboratory of Meteorological Disaster (Nanjing University of Information Science and Technology) of the Ministry of Education (Grant No. KLME1414)+2 种基金the National Natural Science Foundation of China (Grant No. 41574179)the Natural Science Foundation of Excellent Youth Program of China (Grant No. 41622501)“The Hundred Talents Program” of the Chinese Academy of Sciences (Grant No. 2013068)
文摘In this paper, we report the location results for the parent lightning strokes of more than 30 red sprites observed over an asymmetric mesoscale convective system(MCS) on 30 July 2015 in Shandong Province, China, with a long-baseline lightning location network of very-low-frequency/low-frequency magnetic field sensors. The results show that almost all of these cloud-to-ground(CG) strokes are produced during the mature stage of the MCS, and are predominantly located in the trailing stratiform region, which is similar to analyses of sprite-productive MCSs in North America and Europe. Comparison between the location results for the sprite-producing CG strokes and those provided by the World Wide Lightning Location Network(WWLLN) indicates that the location accuracy of WWLLN for intense CG strokes in Shandong Province is typically within 10 km, which is consistent with the result based on analysis of 2838 sprite-producing CG strokes in the continental United States. Also, we analyze two cases where some minor lightning discharges in the parent flash of sprites can also be located, providing an approach to confine the thundercloud region tapped by the sprite-producing CG strokes.
基金supported by the U.S. Department of Energy, Office of Science, and Office of the Basic Energy Sciences, under Contract DE-AC-02-06CH11357~~
文摘Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discussing this technique in catalysis.However,the mechanism on how the deposited materials improve the catalyst stability and tune the reaction selectivity is still unclear.Herein,catalytic systems created via ALD on stepwise preparation and/or modification under self-limiting reaction conditions are summarized.The effects of deposited materials in terms of electronic/geometry modification over the catalytic nanoparticles(NPs)are discussed.These effects explain the mechanism of the catalytic stability improvement and the selectivity modification.The unique properties of ALD for designing new catalytic systems are further investigated for building up photocatalytic reaction nanobowls,tandem catalyst and bi-active-component metallic catalytic systems.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.81772406,81974341,81991511,81625015,and 81902268)the Natural Science Foundation of Guangdong Province(2020A1515010207 and 2022A1515010431)the China Postdoctoral Science Foundation(2019M663264 and 2019TQ0385).
文摘Increasing evidence shows that adipokines play a vital role in the development of rheumatoid arthritis(RA).Fatty acid-binding protein 4(FABP4),a novel adipokine that regulates inflammation and angiogenesis,has been extensively studied in a variety of organs and diseases.However,the effect of FABP4 on RA remains unclear.Here,we found that FABP4 expression was upregulated in synovial M1-polarized macrophages in RA.The increase in FABP4 promoted synovitis,angiogenesis,and cartilage degradation to exacerbate RA progression in vivo and in vitro,whereas BMS309403(a FABP4 inhibitor)and anagliptin(dipeptidyl peptidase 4 inhibitor)inhibited FABP4 expression in serum and synovial M1-polarized macrophages in mice to alleviate RA progression.Further studies showed that constitutive activation of mammalian target of rapamycin complex 1(mTORC1)by TSC1 deletion specifically in the myeloid lineage regulated FABP4 expression in macrophages to exacerbate RA progression in mice.In contrast,inhibition of mTORC1 by ras homolog enriched in brain(Rheb1)disruption specifically in the myeloid lineage reduced FABP4 expression in macrophages to attenuate RA development in mice.Our findings established an essential role of FABP4 that is secreted by M1-polarized macrophages in synovitis,angiogenesis,and cartilage degradation in RA.BMS309403 and anagliptin inhibited FABP4 expression in synovial M1-polarized macrophages to alleviate RA development.Hence,FABP4 may represent a potential target for RA therapy.
基金supported by the National Natural Science Foundation of China (Grant No 21173215, 21033009 and 11079005)
文摘A versatile wet chemistry method is developed for filling of subnanometer sized metal particles in carbon nanotubes with a diameter smaller than 1.5 nm. As an example, we showed that a confined bi-component Pd-V catalyst exhibit a higher benzene hydroxylation activity compared with that within multi-walled carbon nanotubes.
基金financially sponsored by a grant from Talent Development Project of Hebei Province, No. 2010353the Key Medical Research Subject of Hebei Province Health Department, No. 20090582
文摘The present study established a rat model of cerebral ischemia/reperfusion injury using four-vessel occlusion and found that hippocampal CA1 neuronal morphology was damaged, and that there were reductions in hippocampal neuron number and DNA-binding activity of cAMP response element binding protein and CCAAT/enhancer binding protein, accompanied by decreased learning and memory ability. These findings indicate that decline of hippocampal cAMP response element binding protein and CCAAT/enhancer binding protein DNA-binding activities may contribute to neuronal injury and learning and memory ability reduction induced by cerebral ischemia/reperfusion injury.
基金supported by the National Key Basic Research and Development Program (2017YFC1501501)National Natural Science Foundation of China (41574179, 41875006)+4 种基金National Natural Science Foundation for Excellent Youth of China (41622501)"The Hundred Talents Program" of Chinese Academy of Sciences (2013068)supported by funding from the NOAA Office of Global Programs for the Global Precipitation Climatology Project (GPCP)by NASA via the Tropical Rainfall Measuring Mission (TRMM)supported by NASA's HQ Earth S cience Data Systems (ESDS) Program
文摘The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from the sprite-producing lightning were measured at five ground stations, making it possible to locate and identify the individual causative lightning discharges for different elements in this dancing sprite event. The results of our analyses indicate that the sprites were produced above the trailing stratiform region of the MCS, and their parent strokes were located mainly in the peripheral area of the stratiform. The lateral offset between sprites and causative strokes ranges from a few km to more than 50 km. In a particularly bright sprite, with a distinct halo feature and streamers descending down to an altitude of approximately 48 km, the sprite current signal identified in the electric sferic, measured at a range of about 1,110 km, peaked at approximately 1 ms after the return stroke.
基金The National Natural Science Foundation of China(Grant Nos.41630425,41761144074 and 41875007)supported the researchthe Chinese Academy of Sciences for the CAS-PIFI fellowship grant。
文摘A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources observed from the Beijing Lightning Network(BLNET)were used to obtain information about the thunderstorm cells,which are significantly valuable in real-time.The boundaries of thunderstorm cells were obtained through the neighborhood technique.After smoothing,these boundaries were used to track the movement of thunderstorms and then extrapolated to nowcast the lightning approaching in an area of concern.The algorithm can deliver creditable results prior to a thunderstorm arriving at the area of concern,with accuracies of 63%,80%,and 91%for lead times of 30,15,and 5 minutes,respectively.The real-time observations of total lightning appear to be significant for thunderstorm tracking and lightning nowcasting,as total lightning tracking could help to fill the observational gaps in radar reflectivity due to the attenuation by hills or other obstacles.The lightning data used in the algorithm performs well in tracking the active thunderstorm cells associated with lightning activities.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41630425, 41761144074)
文摘Leader propagation is a fundamental issue in lightning physics. The propagation characteristics of positive leaders and negative leaders are summarized and compared based on data from high-speed camera and electromagnetic field in rocket-triggered lightning and tower-initiated lightning discharges; available channel base current data recorded in rocket-triggered lightning are also used. The negative leaders propagate in a stepped fashion accompanied by many branches. The stems ahead of the negative leader tip determine the manner and direction of the leader propagation, and even the branching and winding of the lightning channel. The impulsive current, electromagnetic field, and related optical images suggest that the positive leader may develop in a step-like fashion at its initial stage of triggered lightning. However, the stepping processes of the positive leader are obviously different from those of the negative leader. Tower-initiated lightning revealed that the most conspicuous characteristics of the stepwise positive leader involve the intermittent brush-like corona zone in front of the leader tip and the luminosity enhancement of the channel behind the tip. In rockettriggered lightning flashes, the charge transferred during an individual step for the negative leader was nearly an order greater than for the positive counterpart. The successive streamers ahead of the leader tip are essential for both negative and positive leader propagation, and the stems could be formed from one or more streamers in the previous negative streamer zone with the main leader channel dim. High-resolution observation of tower lightning also revealed a new type of bidirectional recoil leader, with polarity contrary to the traditional one, traversing in negative channels associated with tower-initiated and rocket-triggered lightning.
基金This work was financially supported by the Ministry of Education of China (No.KB20026)
文摘Lithium aluminosilicate （LAS） glasses are generally difficult to prepare because of their high melting temperature. In this study, the preparation of LAS glasses was achieved at a relatively low melting temperature. The batch containing MgO-ZnO-LiEO- Al2O3-SiO2 was melted in a platinum crucible at 1550℃ for 2 h and was then followed by two- or three-step heat treatment processes for nucleation and crystal growth. The characterizations were carried out by differential thermal analysis, X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and UV-Vis-NIR scanning spectrophotometry. The hexagonal stuffed β-eucryptite solid solution crystallized at 840-960℃. Most of the hexagonal β-eucryptite solid solution transformed into the tetragonal β-spodumene solid solution at 1100℃. Almost all the aluminum atoms entered into the tetrahedral sites in the aluminosilicate network of the 6- eucryptite/β-quartz solid solution. All of the Al atoms did not belong to the aluminosilicate network of the β-spodumene solid solution. The glass ceramic with a mean grain size of 10-20 nm is transparent, the transmittance reaches -85% in the visible light wavelength.
基金supported by the National Natural Science Foundation of China(Grant numbers 21876107,21607103)。
文摘In this work,cathode materials of spent lithium-ion ternary batteries are recovered and used as metal precursor to prepare multi-metal oxides MnO_(x)(SY)and GdMnO_(3)(SY)via combustion method and sol-gel method,respectively.Furthermore,a series of MnO_(x)(SY)-n and GdMnO_(3)(SY)-n(n=0.05,0.10,1.00,4.00,n represents the dilute HNO_(3) concentration)catalysts are fabricated by acid treatment of MnO_(x)(SY)and GdMnO_(3)(SY)samples and catalytic activities of oxygenated VOCs oxidation over all the prepared catalysts are investigated.Catalytic evaluation results show that acid-treated MnO_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples perform the optimum VOCs removal efficiency respectively,which may be attributed to their obvious enhancement of physicochemical properties.In detail,Mn O_(x)(SY)-0.10 and GdMnO_(3)(SY)-0.05 samples exhibit the larger specific surface area,bigger amount of surface high-valence metal ions(Mn^(4+),Co^(3+),Ni^(3+)),more abundant adsorbed oxygen species and better low-temperature reducibility,which can play a crucial role in the significant improvement of VOCs oxidation.In situ DRIFTS results imply that the possible main intermediates are-OCO,-COO and-C-O species produced during VOCs oxidation.Possible by-products are further determined via TD/GC-MS analysis.
文摘Multi-layer microbubble has great potential in enabling the corporation of medical imaging with tumor therapy such as drug and gene delivery of therapeutics or other functional materials in medical applications. Microfluidic technique has advanced over the last decade and showed great promise in replacing traditional microbubble generating method. In this paper, a multi-layer microbubble structure was produced with the aspect as potentially used for drug loaded microbubble contrast agents.
文摘[Objectives]To analyze the common compatibility contraindications of breviscapine for injection,and to provide references for clinical rational drug use.[Methods]The pH distribution of the combined drugs in the report on the compatibility contraindications of breviscapine for injection and was analyzed.[Results]Breviscapine for injection may become turbid or precipitated when mixed with drugs whose pH are lower;it can make the liquid discoloration in a strong alkaline solution.[Conclusions]Breviscapine for injection should not be combined with drugs whose pH are lower,especially drugs with pH lower than 4.2.Breviscapine for injection should not be used with drugs with strong alkaline.It is recommended to use Breviscapine for injection separately.
文摘Determination of the grouting anchor pullout force is a key step during the design of anchor-pull retaining wall, but it is mostly determined relied on empirical formula at present, and the rationality and the safety cannot be effectively guaranteed. Based on the engineering case of the gravity retaining wall of Qinglin Freeway, the model test was designed, and combined with the results of the ABAQUS finite element numerical analysis, it was analyzed that how the anchor axial pulling force distributes. The results showed that the force of the anchor near the wall bolt was large and which far from the wall was small and the ultimate pullout force was proportional to the length, diameter and shear strength. When the end tension of the anchor was small, the top load played a leading role on the anchor tension. This conclusion confirmed the calculation formula of ultimate pullout force was and provided a theoretical basis for anchor-pull retaining wall design and calculation.
