The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional meth...The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method.展开更多
As industrialization and informatization becomemore deeply intertwined,industrial control networks have entered an era of intelligence.The connection between industrial control networks and the external internet is be...As industrialization and informatization becomemore deeply intertwined,industrial control networks have entered an era of intelligence.The connection between industrial control networks and the external internet is becoming increasingly close,which leads to frequent security accidents.This paper proposes a model for the industrial control network.It includes a malware containment strategy that integrates intrusion detection,quarantine,and monitoring.Basedonthismodel,the role of keynodes in the spreadofmalware is studied,a comparisonexperiment is conducted to validate the impact of the containment strategy.In addition,the dynamic behavior of the model is analyzed,the basic reproduction number is computed,and the disease-free and endemic equilibrium of the model is also obtained by the basic reproduction number.Moreover,through simulation experiments,the effectiveness of the containment strategy is validated,the influence of the relevant parameters is analyzed,and the containment strategy is optimized.In otherwords,selective immunity to key nodes can effectively suppress the spread ofmalware andmaintain the stability of industrial control systems.The earlier the immunization of key nodes,the better.Once the time exceeds the threshold,immunizing key nodes is almost ineffective.The analysis provides a better way to contain the malware in the industrial control network.展开更多
A preliminary miRNA screening showed that expression levels of rno-miRNA-27a-3p were significantly increased in the serum and brain tissues of rats undergoing cerebral ischemia.In recent years,there is evidence of the...A preliminary miRNA screening showed that expression levels of rno-miRNA-27a-3p were significantly increased in the serum and brain tissues of rats undergoing cerebral ischemia.In recent years,there is evidence of the protective capacity of the saponins extracted from panax ginseng and its primary active ingredient ginsenosideRg1oncerebral ischemic injury.Methods:Fetal rat neurons(FRNs)were cultured in glucose-and-serumfree medium and exposed to hypoxia to establish a cerebral ischemia model in vitro(oxygen and glucose deprivation model,OGD).Antioxidant indexes(CAT,SOD),inflammatory markers(MPO,TNF-αand IL-6),and the expression of apoptosis and proliferation associated proteins(NF kB-p65,Caspase 3-cleaved,BCL-2)were examined.Results:Pre-treatment of Rg1(30–100μg/mL)could effectively inhibit the decline of antioxidant indexes(CAT,SOD)and increase in inflammatory markers(MPO,TNF-αand IL-6),and effectively inhibited the apoptosis in FRNs induced by OGD in a gradient-dependent manner.The mechanism analysis showed that the role of Rg1 in protecting against ischemia-induced neuron damage depends on its indirect up-regulation of PPAR protein via suppression of rnomiRNA-27a-3p.Moreover,these effects of Rg1 could be reversed by exogenous rno-miRNA-27a-3p and PPAR gene silencing in FRNs exposed to OGD.Conclusion:To summarize,our study demonstrates that Rg1 could effectively attenuate neuronal damage caused by cerebral ischemia via the rno-miRNA-27a-3p/PPARγpathway.Further,clarification of the novel mechanism will certainly improve our previous understanding of the role of Rg1 and enhancing its level in treatments for alleviating ischemic brain injury.展开更多
Water resources are one of the key factors restricting the development of arid areas,and cloud water resources is an important part of water resources.The arid region of central Asia is the core region of the current ...Water resources are one of the key factors restricting the development of arid areas,and cloud water resources is an important part of water resources.The arid region of central Asia is the core region of the current national green silk road construction,and is the largest arid region in the world.Based on cloud cover data of ECMWF,the current study analyzed temporal and spatial characteristics of cloud properties in arid regions of Central Asia between 1980 and 2019.Our findings show that:(1)From the point of view of spatial distribution,total cloudiness in arid regions of Central Asia was low in the south and high in the north.The distribution of high cloud frequency and medium cloud frequency was higher in the south and lower in the north,while low cloud frequency distribution was low in the south and high in the north.(2)In terms of time,the variation of cloud cover and cloud type frequency had obvious seasonal characteristics.From winter to spring,cloud cover increased,and the change of cloud type frequency increased.From spring to summer,cloud cover continued to increase and the change of cloud type frequency increased further.Cloud cover began to decrease from summer to autumn,and the change of cloud type frequency also decreased.(3)Generally,average total cloud cover decreased in most of central Asia,and high and medium cloud cover increased while low cloud cover decreased.This study provides a reference for the rational development of cloud resources in the region.展开更多
Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyze...Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyzed the fracture surface characteristics induced by supercritical carbon dioxide(SC-CO_(2))and water in open-hole and perforation completion conditions under triaxial stresses.A simple calculation method was proposed to quantitatively analyze the fracture surface area and roughness in macro-level based on three-dimensional(3D)scanning data.In micro-level,scanning electron micrograph(SEM)was used to analyze the features of fracture surface.The results showed that the surface area of the induced fracture increases with perforation angle for both SC-CO_(2)and water fracturing,and the surface area of SC-CO_(2)-induced fracture is 6.49%e58.57%larger than that of water-induced fracture.The fractal dimension and surface roughness of water-induced fractures increase with the increase in perforation angle,while those of SC-CO_(2)-induced fractures decrease with the increasing perforation angle.A considerable number of microcracks and particle peeling pits can be observed on SC-CO_(2)-induced fracture surface while there are more flat particle surfaces in water-induced fracture surface through SEM images,indicating that fractures tend to propagate along the boundary of the particle for SC-CO_(2)fracturing while water-induced fractures prefer to cut through particles.These findings are of great significance for analyzing fracture mechanism and evaluating fracturing stimulation performance.展开更多
Catalytic CO_(2)conversion has witnessed a dynamic growth in recent decades.Various materials have been applied to reduce CO_(2)into fuels and value-added chemicals.Normally,the powder-based catalysts cannot be direct...Catalytic CO_(2)conversion has witnessed a dynamic growth in recent decades.Various materials have been applied to reduce CO_(2)into fuels and value-added chemicals.Normally,the powder-based catalysts cannot be directly utilized for CO_(2)conversion.Much attention was paid to the study of catalytic membranes in order to overcome this issue,since it is convenient for catalytic membranes to be employed in devices for practical applications.In this review,the recent research development of porous catalytic membranes for CO_(2)conversion is summarized.The preparations of representative porous catalytic membranes and their CO_(2)conversion methods,including electrocatalysis,photocatalysis,photoelectrocatalysis,thermalcatalysis and biocatalysis,are discussed in detail.This review is expected to provide deep understanding on the utilization of porous catalytic membranes for CO_(2)conversion.展开更多
Semiconductor nanomaterial-based epitaxial heterostructures with precisely controlled compositions and morphologies are of great importance for various applications in optoelectronics,thermoelectrics,and catalysis.Unt...Semiconductor nanomaterial-based epitaxial heterostructures with precisely controlled compositions and morphologies are of great importance for various applications in optoelectronics,thermoelectrics,and catalysis.Until now,various kinds of epitaxial heterostructures have been constructed.In this minireview,we will first introduce the synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods.Various architectures based on different kinds of seeds or templates are illustrated,and their growth mechanisms are discussed in detail.Then,the applications of epitaxial heterostructures in optoelectronics,catalysis,and thermoelectrics are described.Finally,we provide some challenges and personal perspectives for the future research directions of semiconductor nanomaterial-based epitaxial heterostructures.展开更多
[Objectives] To compare content of proanthocyanidins and polysaccharides in wild Lycium ruthenicum. [Methods] The wild L. ruthenicum collected from different regions such as Qinghai, Inner Mongolia, Ningxia and Gansu ...[Objectives] To compare content of proanthocyanidins and polysaccharides in wild Lycium ruthenicum. [Methods] The wild L. ruthenicum collected from different regions such as Qinghai, Inner Mongolia, Ningxia and Gansu Province were taken as the research objects. The conventional indicators such as proanthocyanidins and polysaccharides of the experimental materials were determined, and the proanthocyanidins and polysaccharides of the experimental materials in different regions were compared and analyzed. The difference in content and correlation, and the cluster analysis method were used to divide clusters of the experimental materials. [Results] The absorbance of proanthocyanidins in the fruit of wild L. ruthenicum was No.4>No.1>No.5>No.6>No.3>No.2, among which the absorbance of anthocyanin(2.43) of wild L. ruthenicum variety No.4 was significantly higher than other experimental materials(P<0.05), and proanthocyanidin of No.2 had the lowest absorbance value of 1.35. There was no significant difference between No.3 and No.6(P>0.05), and there were significant differences among other experimental materials(P<0.05). The content of polysaccharides was: No.3>No.7>No.2>No.4>No.5>No.6>No.1; there was no significant difference between No.3 and No.7(P>0.05), but significantly higher than other materials(P<0.05). Besides, proanthocyanidins and polysaccharides showed significant variability, but there was no consistency in the correlation between them. [Conclusions] In terms of the absorbance of proanthocyanidins, the experimental materials No.1 and No.4 can be classified into a cluster; experimental materials No.2, No.3, No.5 and No.6 can be classified into another cluster. This can provide a theoretical basis for the introduction and breeding of fine varieties.展开更多
There is an increasing demand for rechargeable batteries in high-performance energy storage systems.The current dominating Li-ion batteries are limited by price,resource availability,as well as their theoretical capac...There is an increasing demand for rechargeable batteries in high-performance energy storage systems.The current dominating Li-ion batteries are limited by price,resource availability,as well as their theoretical capacities.So that the community has started to explore alternative battery chemistries.As a promising multivalent battery type,rechargeable magnesium batteries(RMBs)have attracted increasing attention because of high safety,high volumetric energy density,and low cost thanks to abundant resource of Mg.However,the development of high-performance anodes is still hampered by formation of passivating layers on the Mg surface.Additionally,dendrites can also grow under certain conditions with pure Mg anodes,which requires further studies for reliable operation window and substitutes.Therefore,this review specifically aims to provide an overview on the often overlooked yet very important anode materials of RMBs,with the hope to inspire more attention and research efforts for the achievement of over-all better performance of future RMBs.c 2020 Published by Elsevier B.V.on behalf of Chongqing University.展开更多
It becomes increasingly clear that non-uniform distribution of immiscible fluids in porous rock is particularly relevant to seismic wave dispersion.White proposed a patchy saturation model in 1975, in which spherical ...It becomes increasingly clear that non-uniform distribution of immiscible fluids in porous rock is particularly relevant to seismic wave dispersion.White proposed a patchy saturation model in 1975, in which spherical gas pockets were located at the center of a liquid saturated cube.For an extremely light and compressible inner gas,the physical properties can be approximated by a vacuum with White's model.The model successfully analyzes the dispersion phenomena of a P-wave velocity in gas-watersaturated rocks.In the case of liquid pocket saturation, e.g., an oil-pocket surrounded by a water saturated host matrix, the light fluid-pocket assumption is doubtful, and few works have been reported in White's framework.In this work, Poisson's ratio, the bulk modulus, and the effective density of a dual-liquid saturated medium are formulated for the heterogeneous porous rocks containing liquid-pockets.The analysis of the difference between the newly derived bulk modulus and that of White's model shows that the effects of liquid-pocket saturation do not disappear unless the porosity approaches zero.The inner pocket fluid can no longer be ignored.The improvements of the P-wave velocity predictions are illustrated with two examples taken from experiments, i.e., the P-wave velocity in the sandstone saturated by oil and brine and the P-wave velocity for heavy oils and stones at different temperatures.展开更多
Soybean agglutinin(SBA)is an important anti-nutritional factor in soybean.SBA can induce animal growth inhibition,cause pathological changes of intestinal tissue,and decrease in the immune system functioning.Recently,...Soybean agglutinin(SBA)is an important anti-nutritional factor in soybean.SBA can induce animal growth inhibition,cause pathological changes of intestinal tissue,and decrease in the immune system functioning.Recently,a great deal of research has been done on the effects of SBA on cell morphology,division,apoptosis,autophagy,as well as the correlated signal transduction pathway.This review mainly covers the chemical and biological characteristics of SBA,describes the multifaceted aspects of SBA anti-nutritional functions,and highlights the possible cellular and molecular mechanism of anti-nutritional effects of SBA.This review has important implications for the prevention and treatment of SBA-induced diseases,drug development,processing techniques of plant products,prevention of food-borne toxins,as well as human and animal health protection.展开更多
Apigenin (4’, 5, 7-trihydroxyflavone, AP), a dietary flavonoid, is reported to have several therapeutic effects in different diseases including cancer. In the present study, in order to explore the potential mechanis...Apigenin (4’, 5, 7-trihydroxyflavone, AP), a dietary flavonoid, is reported to have several therapeutic effects in different diseases including cancer. In the present study, in order to explore the potential mechanism and provide the references for further studies, we investigated the effect of apigenin at various dosages on the hepatic oxidative stress of male rats. Totally 48 SD male rats were randomly divided into control group (saline, 1 ml/100g·bw), low-dose group (AP, 234 mg/kg·bw), middle-dose group (AP, 468 mg/kg·bw) and high-dose group (AP, 936 mg/kg·bw). The rats were administered with apigenin or saline via intragastriation once a day, 6 days per week, and 5 consecutive weeks. Rats were sacrificed and the livers were harvested and then immediately preserved at ﹣20°C. Liver homogenate was prepared before detection. Hepatic malondialdehyde (MDA), nitric oxide syntheses (NOS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC) and glutathione (GSH) were determined by colorimetric methods according to the provided procedures. The weights of liver and spleen in apigenin treatment groups did not reveal statistically significant difference when compared with that in the control group (P > 0.05). Total protein (TP), albumin (ALB) and globulin (GLO) in apigenin treatment groups were significantly lower than those in the control group (P < 0.05). SOD in the middle-dose group (AP, 468 mg/kg·bw) and high-dose group (AP, 936 mg/kg·bw) were significantly higher than that in the control group (P < 0.05). T-AOC, CAT and GSH-Px in apigenin treatment groups were significantly lower than those in the control group (P < 0.05). In high-dose AP group (AP, 936 mg/kg·bw), apigenin can result in the reduction of T-AOC, thus leading to the oxidative damage of liver tissues. In contrast, in middle-dose AP group (AP, 468 mg/kg·bw), apegenin can reduce the elimination capacity of oxygen free radicals.展开更多
In this paper,we show the relation between the existence of twisted conical K?hler-Ricci solitons and the greatest log Bakry-Emery-Ricci lower bound on Fano manifolds.This is based on our proofs of some openness theor...In this paper,we show the relation between the existence of twisted conical K?hler-Ricci solitons and the greatest log Bakry-Emery-Ricci lower bound on Fano manifolds.This is based on our proofs of some openness theorems on the existence of twisted conical Kahler-Ricci solitons,which generalize Donaldson’s existence conjecture and the openness theorem of the conical K?hler-Einstein metrics to the conical soliton case.展开更多
Non-small cell lung cancer(NSCLC)ranks as one of the leading causes of cancer-related deaths worldwide.Despite the prominence and effectiveness of kinase-target therapies in NSCLC treatment,these drugs are suitable fo...Non-small cell lung cancer(NSCLC)ranks as one of the leading causes of cancer-related deaths worldwide.Despite the prominence and effectiveness of kinase-target therapies in NSCLC treatment,these drugs are suitable for and beneficial to a mere~30%of NSCLC patients.Consequently,the need for novel strategies addressing NSCLC remains pressing.Deubiquitinases(DUBs),a group of diverse enzymes with well-defined catalytic sites that are frequently overactivated in cancers and associated with tumorigenesis and regarded as promising therapeutic targets.Nevertheless,the mechanisms by which DUBs promote NSCLC remain poorly understood.Through a global analysis of the 97 DUBs’contribution to NSCLC survival possibilities using The Cancer Genome Atlas(TCGA)database,we found that high expression of Josephin Domain-containing protein 2(JOSD2)predicted the poor prognosis of patients.Depletion of JOSD2 significantly impeded NSCLC growth in both cell/patient-derived xenografts in vivo.Mechanically,we found that JOSD2 restricts the kinase activity of LKB1,an important tumor suppressor generally inactivated in NSCLC,by removing K6-linked polyubiquitination,an action vital for maintaining the integrity of the LKB1-STRAD-MO25 complex.Notably,we identified the first small-molecule inhibitor of JOSD2,and observed that its pharmacological inhibition significantly arrested NSCLC proliferation in vitro/in vivo.Our findings highlight the vital role of JOSD2 in hindering LKB1 activity,underscoring the therapeutic potential of targeting JOSD2 in NSCLC,especially in those with inactivated LKB1,and presenting its inhibitors as a promising strategy for NSCLC treatment.展开更多
Magnesium phosphate bone cement has become a widely used orthopedic implant due to the advantages of fast-setting and high early strength. However, developing magnesium phosphate cement possessing applicable injectabi...Magnesium phosphate bone cement has become a widely used orthopedic implant due to the advantages of fast-setting and high early strength. However, developing magnesium phosphate cement possessing applicable injectability, high strength, and biocompatibility simultaneously remains a significant challenge. Herein, we propose a strategy to develop high-performance bone cement and establish a trimagnesium phosphate cement (TMPC) system. The TMPC exhibits high early strength, low curing temperature, neutral pH, and excellent injectability, overcoming the critical limitations of recently studied magnesium phosphate cement. By monitoring the hydration pH value and electroconductivity, we demonstrate that the magnesium-to-phosphate ratio could manipulate the components of hydration products and their transformation by adjusting the pH of the system, which will influence the hydration speed. Further, the ratio could regulate the hydration network and the properties of TMPC. Moreover, in vitro studies show that TMPC has outstanding biocompatibility and bone-filling capacity. The facile preparation properties and these advantages of TMPC render it a potential clinical alternative to polymethylmethacrylate and calcium phosphate bone cement. This study will contribute to the rational design of high-performance bone cement.展开更多
Stable,efficient and high color rendering index all-inorganic color converters are urgently demanded for white laser diodes.Phosphor-in-glass(PiG),possessing the advantages of phosphors excellent quantum efficiency as...Stable,efficient and high color rendering index all-inorganic color converters are urgently demanded for white laser diodes.Phosphor-in-glass(PiG),possessing the advantages of phosphors excellent quantum efficiency as well as favorable chemical and thermal stability of glass,has attracted widespread attention.There have been only very few reports of Y_(1.31)Ce_(0.09)Gd_(1.6)Al_(5)O_(12)(Ce:GdYAG)PiG for solid-state laser light-ing.Herein,a series of Ce:GdYAG PiG samples are fabricated by a simple solid-state sintering method.Impressively,the supreme internal quantum efficiency of as-prepared PiG is 91%,which is very close to original phosphors(95%).Furthermore,PiG exhibits a high thermal conductivity(1.844 W m^(−1)K^(−1))and a maximum transparency(62%).Remarkably,by changing the concentration of phosphors and the thickness of PiG samples,a luminous efficacy of 163.5 lm/W,high color rendering index of 74.8 and low correlated color temperature of 4806.8 K are achieved under blue laser irradiation.These results indicate that the Ce:GdYAG PiG samples have shown tremendous application foreground as all-inorganic color converter for solid-state laser lighting.展开更多
As a revolutionary observation tool in life science,biomedical,and material science,optical microscopy allows imaging of samples with high spatial resolution and a wide field of view.However,conventional microscopy me...As a revolutionary observation tool in life science,biomedical,and material science,optical microscopy allows imaging of samples with high spatial resolution and a wide field of view.However,conventional microscopy methods are limited to single imaging and cannot accomplish real-time image processing.The edge detection,image enhancement and phase visualization schemes have attracted great interest with the rapid development of optical analog computing.The two main physical mechanisms that enable optical analog computing originate from two geometric phases:the spin-redirection Rytov-Vlasimirskii-Berry(RVB)phase and the Pancharatnam-Berry(PB)phase.Here,we review the basic principles and recent research progress of the RVB phase and PB phase based optical differentiators.Then we focus on the innovative and emerging applications of optical analog computing in microscopic imaging.Optical analog computing is accelerating the transformation of information processing from classical imaging to quantum techniques.Its intersection with optical microscopy opens opportunities for the development of versatile and compact optical microscopy systems.展开更多
Developing sustainable and clean energy-conversion techniques is one of the strategies to simultaneously meet the global energy demand,save fossil fuels and protect the environment,in which nanocatalysts with high act...Developing sustainable and clean energy-conversion techniques is one of the strategies to simultaneously meet the global energy demand,save fossil fuels and protect the environment,in which nanocatalysts with high activity,selectivity and durability are of great importance.Intermetallic nanocrystals,featuring their ordered atomic arrangements and predictable electronic structures,have been recognized as a type of active and durable catalysts in energy-related applications.In this minireview,the very recent progress in the syntheses and electrocatalytic applications of noble metal-based intermetallic nanocrystals is summarized.Various synthetic strategies,including the conventional thermal annealing approach and its diverse modifications,as well as the wet-chemical synthesis,for the construction of binary,ternary and high-entropy intermetallic nanocrystals have been discussed with representative examples,highlighting their strengths and limitations.Then,their electrocatalytic applications toward oxygen reduction reaction,small molecule oxidation reactions,hydrogen evolution reaction,CO_(2)/CO reduction reactions,and nitrogen reduction reaction are discussed,with the emphasis on how the ordered intermetallic structures contribute to the enhanced performance.We conclude the minireview by addressing the current challenges and opportunities of intermetallic nanocrystals in terms of syntheses and electrocatalytic applications.展开更多
基金The work described in this paper was partially supported by grants from the Research Grant Council of the Hong Kong Special Administrative Region,China(Project Nos.HKU 17207518 and R5037-18).
文摘The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method.
基金Scientific Research Project of Liaoning Province Education Department,Code:LJKQZ20222457&LJKMZ20220781Liaoning Province Nature Fund Project,Code:No.2022-MS-291.
文摘As industrialization and informatization becomemore deeply intertwined,industrial control networks have entered an era of intelligence.The connection between industrial control networks and the external internet is becoming increasingly close,which leads to frequent security accidents.This paper proposes a model for the industrial control network.It includes a malware containment strategy that integrates intrusion detection,quarantine,and monitoring.Basedonthismodel,the role of keynodes in the spreadofmalware is studied,a comparisonexperiment is conducted to validate the impact of the containment strategy.In addition,the dynamic behavior of the model is analyzed,the basic reproduction number is computed,and the disease-free and endemic equilibrium of the model is also obtained by the basic reproduction number.Moreover,through simulation experiments,the effectiveness of the containment strategy is validated,the influence of the relevant parameters is analyzed,and the containment strategy is optimized.In otherwords,selective immunity to key nodes can effectively suppress the spread ofmalware andmaintain the stability of industrial control systems.The earlier the immunization of key nodes,the better.Once the time exceeds the threshold,immunizing key nodes is almost ineffective.The analysis provides a better way to contain the malware in the industrial control network.
基金supported by the National Natural Science Foundation of China,Nos.81973317,81374007,81870977the Natural Science Foundation of Heilongjiang Province,HL2019H062+1 种基金the Projects of Basic Scientific Research Business Expenses in Higher Education Institutions of Heilongjiang Province,No.2018-KYYWF-MY-005the Students Innovative and the Entrepreneurship Training Scientific Research Foundation of Heilongjiang Province,No.102292017001.
文摘A preliminary miRNA screening showed that expression levels of rno-miRNA-27a-3p were significantly increased in the serum and brain tissues of rats undergoing cerebral ischemia.In recent years,there is evidence of the protective capacity of the saponins extracted from panax ginseng and its primary active ingredient ginsenosideRg1oncerebral ischemic injury.Methods:Fetal rat neurons(FRNs)were cultured in glucose-and-serumfree medium and exposed to hypoxia to establish a cerebral ischemia model in vitro(oxygen and glucose deprivation model,OGD).Antioxidant indexes(CAT,SOD),inflammatory markers(MPO,TNF-αand IL-6),and the expression of apoptosis and proliferation associated proteins(NF kB-p65,Caspase 3-cleaved,BCL-2)were examined.Results:Pre-treatment of Rg1(30–100μg/mL)could effectively inhibit the decline of antioxidant indexes(CAT,SOD)and increase in inflammatory markers(MPO,TNF-αand IL-6),and effectively inhibited the apoptosis in FRNs induced by OGD in a gradient-dependent manner.The mechanism analysis showed that the role of Rg1 in protecting against ischemia-induced neuron damage depends on its indirect up-regulation of PPAR protein via suppression of rnomiRNA-27a-3p.Moreover,these effects of Rg1 could be reversed by exogenous rno-miRNA-27a-3p and PPAR gene silencing in FRNs exposed to OGD.Conclusion:To summarize,our study demonstrates that Rg1 could effectively attenuate neuronal damage caused by cerebral ischemia via the rno-miRNA-27a-3p/PPARγpathway.Further,clarification of the novel mechanism will certainly improve our previous understanding of the role of Rg1 and enhancing its level in treatments for alleviating ischemic brain injury.
基金financially supported by the National Natural Science Foundation of China (41867030, 41971036)the National Natural Science Foundation innovation research group science foundation of China (41421061)
文摘Water resources are one of the key factors restricting the development of arid areas,and cloud water resources is an important part of water resources.The arid region of central Asia is the core region of the current national green silk road construction,and is the largest arid region in the world.Based on cloud cover data of ECMWF,the current study analyzed temporal and spatial characteristics of cloud properties in arid regions of Central Asia between 1980 and 2019.Our findings show that:(1)From the point of view of spatial distribution,total cloudiness in arid regions of Central Asia was low in the south and high in the north.The distribution of high cloud frequency and medium cloud frequency was higher in the south and lower in the north,while low cloud frequency distribution was low in the south and high in the north.(2)In terms of time,the variation of cloud cover and cloud type frequency had obvious seasonal characteristics.From winter to spring,cloud cover increased,and the change of cloud type frequency increased.From spring to summer,cloud cover continued to increase and the change of cloud type frequency increased further.Cloud cover began to decrease from summer to autumn,and the change of cloud type frequency also decreased.(3)Generally,average total cloud cover decreased in most of central Asia,and high and medium cloud cover increased while low cloud cover decreased.This study provides a reference for the rational development of cloud resources in the region.
基金National Natural Science Foundation of China(Grant No.51804318)the China Postdoctoral Science Foundation Founded Project(Grant No.2019M650963)National Key Basic Research and Development Program of China(Grant No.2014CB239203).
文摘Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyzed the fracture surface characteristics induced by supercritical carbon dioxide(SC-CO_(2))and water in open-hole and perforation completion conditions under triaxial stresses.A simple calculation method was proposed to quantitatively analyze the fracture surface area and roughness in macro-level based on three-dimensional(3D)scanning data.In micro-level,scanning electron micrograph(SEM)was used to analyze the features of fracture surface.The results showed that the surface area of the induced fracture increases with perforation angle for both SC-CO_(2)and water fracturing,and the surface area of SC-CO_(2)-induced fracture is 6.49%e58.57%larger than that of water-induced fracture.The fractal dimension and surface roughness of water-induced fractures increase with the increase in perforation angle,while those of SC-CO_(2)-induced fractures decrease with the increasing perforation angle.A considerable number of microcracks and particle peeling pits can be observed on SC-CO_(2)-induced fracture surface while there are more flat particle surfaces in water-induced fracture surface through SEM images,indicating that fractures tend to propagate along the boundary of the particle for SC-CO_(2)fracturing while water-induced fractures prefer to cut through particles.These findings are of great significance for analyzing fracture mechanism and evaluating fracturing stimulation performance.
基金supported by the Ministry of Education Singapore under the Academic Research Funds(RT12/19 and MOE-MOET2EP10120-0003)the Singapore National Research Foundation Investigatorship(NRF-NRFI2018-03)。
文摘Catalytic CO_(2)conversion has witnessed a dynamic growth in recent decades.Various materials have been applied to reduce CO_(2)into fuels and value-added chemicals.Normally,the powder-based catalysts cannot be directly utilized for CO_(2)conversion.Much attention was paid to the study of catalytic membranes in order to overcome this issue,since it is convenient for catalytic membranes to be employed in devices for practical applications.In this review,the recent research development of porous catalytic membranes for CO_(2)conversion is summarized.The preparations of representative porous catalytic membranes and their CO_(2)conversion methods,including electrocatalysis,photocatalysis,photoelectrocatalysis,thermalcatalysis and biocatalysis,are discussed in detail.This review is expected to provide deep understanding on the utilization of porous catalytic membranes for CO_(2)conversion.
基金supported by MOE under AcRF Tier 2(ARC 19/15,No.MOE2014-T2-2-093,MOE2015T2-2-057,MOE2016-T2-2-103,MOE2017-T2-1-162)and AcRF Tier 1(2016-T1-001-147,2016-T1-002-051,2017-T1001-150,2017-T1-002-119)NTU under Start-Up Grant(M4081296.070.500000)in Singapore.
文摘Semiconductor nanomaterial-based epitaxial heterostructures with precisely controlled compositions and morphologies are of great importance for various applications in optoelectronics,thermoelectrics,and catalysis.Until now,various kinds of epitaxial heterostructures have been constructed.In this minireview,we will first introduce the synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods.Various architectures based on different kinds of seeds or templates are illustrated,and their growth mechanisms are discussed in detail.Then,the applications of epitaxial heterostructures in optoelectronics,catalysis,and thermoelectrics are described.Finally,we provide some challenges and personal perspectives for the future research directions of semiconductor nanomaterial-based epitaxial heterostructures.
基金Supported by Science and Technology Program of Inner Mongolia(201602083)Special Fund for Scientific Research of Inner Mongolia Agricultural University"Special Program for Breeding(Selection)of Animal and Plant Varieties"(YZGC2017023)
文摘[Objectives] To compare content of proanthocyanidins and polysaccharides in wild Lycium ruthenicum. [Methods] The wild L. ruthenicum collected from different regions such as Qinghai, Inner Mongolia, Ningxia and Gansu Province were taken as the research objects. The conventional indicators such as proanthocyanidins and polysaccharides of the experimental materials were determined, and the proanthocyanidins and polysaccharides of the experimental materials in different regions were compared and analyzed. The difference in content and correlation, and the cluster analysis method were used to divide clusters of the experimental materials. [Results] The absorbance of proanthocyanidins in the fruit of wild L. ruthenicum was No.4>No.1>No.5>No.6>No.3>No.2, among which the absorbance of anthocyanin(2.43) of wild L. ruthenicum variety No.4 was significantly higher than other experimental materials(P<0.05), and proanthocyanidin of No.2 had the lowest absorbance value of 1.35. There was no significant difference between No.3 and No.6(P>0.05), and there were significant differences among other experimental materials(P<0.05). The content of polysaccharides was: No.3>No.7>No.2>No.4>No.5>No.6>No.1; there was no significant difference between No.3 and No.7(P>0.05), but significantly higher than other materials(P<0.05). Besides, proanthocyanidins and polysaccharides showed significant variability, but there was no consistency in the correlation between them. [Conclusions] In terms of the absorbance of proanthocyanidins, the experimental materials No.1 and No.4 can be classified into a cluster; experimental materials No.2, No.3, No.5 and No.6 can be classified into another cluster. This can provide a theoretical basis for the introduction and breeding of fine varieties.
基金the German Research Foundation DFG project(LI 2839/1-1)National Natural Science Foundation of China(51971044)MF acknowledges funding from EU research and innovation framework programme via ttE-MAGIC,project(ID:824066)。
文摘There is an increasing demand for rechargeable batteries in high-performance energy storage systems.The current dominating Li-ion batteries are limited by price,resource availability,as well as their theoretical capacities.So that the community has started to explore alternative battery chemistries.As a promising multivalent battery type,rechargeable magnesium batteries(RMBs)have attracted increasing attention because of high safety,high volumetric energy density,and low cost thanks to abundant resource of Mg.However,the development of high-performance anodes is still hampered by formation of passivating layers on the Mg surface.Additionally,dendrites can also grow under certain conditions with pure Mg anodes,which requires further studies for reliable operation window and substitutes.Therefore,this review specifically aims to provide an overview on the often overlooked yet very important anode materials of RMBs,with the hope to inspire more attention and research efforts for the achievement of over-all better performance of future RMBs.c 2020 Published by Elsevier B.V.on behalf of Chongqing University.
基金Project supported by the Open Foundation of SINOPEC Key Laboratory of Geophysics(No.WTYJY-WX2013-04-02)the National Key Basic Research Program of China(973 Program)(No.2014CB239006)the 12th 5-Year Basic Research Program of China National Packaging Corporation(CNPC)(No.2014A-3611)
文摘It becomes increasingly clear that non-uniform distribution of immiscible fluids in porous rock is particularly relevant to seismic wave dispersion.White proposed a patchy saturation model in 1975, in which spherical gas pockets were located at the center of a liquid saturated cube.For an extremely light and compressible inner gas,the physical properties can be approximated by a vacuum with White's model.The model successfully analyzes the dispersion phenomena of a P-wave velocity in gas-watersaturated rocks.In the case of liquid pocket saturation, e.g., an oil-pocket surrounded by a water saturated host matrix, the light fluid-pocket assumption is doubtful, and few works have been reported in White's framework.In this work, Poisson's ratio, the bulk modulus, and the effective density of a dual-liquid saturated medium are formulated for the heterogeneous porous rocks containing liquid-pockets.The analysis of the difference between the newly derived bulk modulus and that of White's model shows that the effects of liquid-pocket saturation do not disappear unless the porosity approaches zero.The inner pocket fluid can no longer be ignored.The improvements of the P-wave velocity predictions are illustrated with two examples taken from experiments, i.e., the P-wave velocity in the sandstone saturated by oil and brine and the P-wave velocity for heavy oils and stones at different temperatures.
基金supported by the National NaturalScienceFoundationofChina(No.31802093)Fund Project of Jilin Agricultural University(2019019).
文摘Soybean agglutinin(SBA)is an important anti-nutritional factor in soybean.SBA can induce animal growth inhibition,cause pathological changes of intestinal tissue,and decrease in the immune system functioning.Recently,a great deal of research has been done on the effects of SBA on cell morphology,division,apoptosis,autophagy,as well as the correlated signal transduction pathway.This review mainly covers the chemical and biological characteristics of SBA,describes the multifaceted aspects of SBA anti-nutritional functions,and highlights the possible cellular and molecular mechanism of anti-nutritional effects of SBA.This review has important implications for the prevention and treatment of SBA-induced diseases,drug development,processing techniques of plant products,prevention of food-borne toxins,as well as human and animal health protection.
文摘Apigenin (4’, 5, 7-trihydroxyflavone, AP), a dietary flavonoid, is reported to have several therapeutic effects in different diseases including cancer. In the present study, in order to explore the potential mechanism and provide the references for further studies, we investigated the effect of apigenin at various dosages on the hepatic oxidative stress of male rats. Totally 48 SD male rats were randomly divided into control group (saline, 1 ml/100g·bw), low-dose group (AP, 234 mg/kg·bw), middle-dose group (AP, 468 mg/kg·bw) and high-dose group (AP, 936 mg/kg·bw). The rats were administered with apigenin or saline via intragastriation once a day, 6 days per week, and 5 consecutive weeks. Rats were sacrificed and the livers were harvested and then immediately preserved at ﹣20°C. Liver homogenate was prepared before detection. Hepatic malondialdehyde (MDA), nitric oxide syntheses (NOS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC) and glutathione (GSH) were determined by colorimetric methods according to the provided procedures. The weights of liver and spleen in apigenin treatment groups did not reveal statistically significant difference when compared with that in the control group (P > 0.05). Total protein (TP), albumin (ALB) and globulin (GLO) in apigenin treatment groups were significantly lower than those in the control group (P < 0.05). SOD in the middle-dose group (AP, 468 mg/kg·bw) and high-dose group (AP, 936 mg/kg·bw) were significantly higher than that in the control group (P < 0.05). T-AOC, CAT and GSH-Px in apigenin treatment groups were significantly lower than those in the control group (P < 0.05). In high-dose AP group (AP, 936 mg/kg·bw), apigenin can result in the reduction of T-AOC, thus leading to the oxidative damage of liver tissues. In contrast, in middle-dose AP group (AP, 468 mg/kg·bw), apegenin can reduce the elimination capacity of oxygen free radicals.
基金supported by National Natural Science Foundation of China(Grant No.12001532)supported by the Special Priority Program SPP 2026“Geometry at Infinity”from the German Research Foundation(DFG)。
文摘In this paper,we show the relation between the existence of twisted conical K?hler-Ricci solitons and the greatest log Bakry-Emery-Ricci lower bound on Fano manifolds.This is based on our proofs of some openness theorems on the existence of twisted conical Kahler-Ricci solitons,which generalize Donaldson’s existence conjecture and the openness theorem of the conical K?hler-Einstein metrics to the conical soliton case.
基金supported by the State Key Program of the Natural Science Foundation of China(81830107)the Natural Science Foundation of China(81973349,82304517)+2 种基金the Key R&D Program of Zhejiang(2022C03077)the Fundamental Research Funds for the Central Universities(226-2023-00059)the China Postdoctoral Science Foundation(2023M733130)。
文摘Non-small cell lung cancer(NSCLC)ranks as one of the leading causes of cancer-related deaths worldwide.Despite the prominence and effectiveness of kinase-target therapies in NSCLC treatment,these drugs are suitable for and beneficial to a mere~30%of NSCLC patients.Consequently,the need for novel strategies addressing NSCLC remains pressing.Deubiquitinases(DUBs),a group of diverse enzymes with well-defined catalytic sites that are frequently overactivated in cancers and associated with tumorigenesis and regarded as promising therapeutic targets.Nevertheless,the mechanisms by which DUBs promote NSCLC remain poorly understood.Through a global analysis of the 97 DUBs’contribution to NSCLC survival possibilities using The Cancer Genome Atlas(TCGA)database,we found that high expression of Josephin Domain-containing protein 2(JOSD2)predicted the poor prognosis of patients.Depletion of JOSD2 significantly impeded NSCLC growth in both cell/patient-derived xenografts in vivo.Mechanically,we found that JOSD2 restricts the kinase activity of LKB1,an important tumor suppressor generally inactivated in NSCLC,by removing K6-linked polyubiquitination,an action vital for maintaining the integrity of the LKB1-STRAD-MO25 complex.Notably,we identified the first small-molecule inhibitor of JOSD2,and observed that its pharmacological inhibition significantly arrested NSCLC proliferation in vitro/in vivo.Our findings highlight the vital role of JOSD2 in hindering LKB1 activity,underscoring the therapeutic potential of targeting JOSD2 in NSCLC,especially in those with inactivated LKB1,and presenting its inhibitors as a promising strategy for NSCLC treatment.
基金supported by grants from The National Key Research and Development Program of China(2022YFB4601402)the National Natural Science Foundation of China(32201109,51772233,51861145306)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2022B1515120052,2021A1515110557)the Self-innovation Research Funding Project of Hanjiang Laboratory(HJL202202A002).
文摘Magnesium phosphate bone cement has become a widely used orthopedic implant due to the advantages of fast-setting and high early strength. However, developing magnesium phosphate cement possessing applicable injectability, high strength, and biocompatibility simultaneously remains a significant challenge. Herein, we propose a strategy to develop high-performance bone cement and establish a trimagnesium phosphate cement (TMPC) system. The TMPC exhibits high early strength, low curing temperature, neutral pH, and excellent injectability, overcoming the critical limitations of recently studied magnesium phosphate cement. By monitoring the hydration pH value and electroconductivity, we demonstrate that the magnesium-to-phosphate ratio could manipulate the components of hydration products and their transformation by adjusting the pH of the system, which will influence the hydration speed. Further, the ratio could regulate the hydration network and the properties of TMPC. Moreover, in vitro studies show that TMPC has outstanding biocompatibility and bone-filling capacity. The facile preparation properties and these advantages of TMPC render it a potential clinical alternative to polymethylmethacrylate and calcium phosphate bone cement. This study will contribute to the rational design of high-performance bone cement.
基金supported by the Key Research and Development Project in Zhejiang Province(No.2021C01024).
文摘Stable,efficient and high color rendering index all-inorganic color converters are urgently demanded for white laser diodes.Phosphor-in-glass(PiG),possessing the advantages of phosphors excellent quantum efficiency as well as favorable chemical and thermal stability of glass,has attracted widespread attention.There have been only very few reports of Y_(1.31)Ce_(0.09)Gd_(1.6)Al_(5)O_(12)(Ce:GdYAG)PiG for solid-state laser light-ing.Herein,a series of Ce:GdYAG PiG samples are fabricated by a simple solid-state sintering method.Impressively,the supreme internal quantum efficiency of as-prepared PiG is 91%,which is very close to original phosphors(95%).Furthermore,PiG exhibits a high thermal conductivity(1.844 W m^(−1)K^(−1))and a maximum transparency(62%).Remarkably,by changing the concentration of phosphors and the thickness of PiG samples,a luminous efficacy of 163.5 lm/W,high color rendering index of 74.8 and low correlated color temperature of 4806.8 K are achieved under blue laser irradiation.These results indicate that the Ce:GdYAG PiG samples have shown tremendous application foreground as all-inorganic color converter for solid-state laser lighting.
基金supported by the National Natural Science Foundation of China(No.12174097)the Natural Science Foundation of Hunan Province(No.2021JJ10008)。
文摘As a revolutionary observation tool in life science,biomedical,and material science,optical microscopy allows imaging of samples with high spatial resolution and a wide field of view.However,conventional microscopy methods are limited to single imaging and cannot accomplish real-time image processing.The edge detection,image enhancement and phase visualization schemes have attracted great interest with the rapid development of optical analog computing.The two main physical mechanisms that enable optical analog computing originate from two geometric phases:the spin-redirection Rytov-Vlasimirskii-Berry(RVB)phase and the Pancharatnam-Berry(PB)phase.Here,we review the basic principles and recent research progress of the RVB phase and PB phase based optical differentiators.Then we focus on the innovative and emerging applications of optical analog computing in microscopic imaging.Optical analog computing is accelerating the transformation of information processing from classical imaging to quantum techniques.Its intersection with optical microscopy opens opportunities for the development of versatile and compact optical microscopy systems.
文摘Developing sustainable and clean energy-conversion techniques is one of the strategies to simultaneously meet the global energy demand,save fossil fuels and protect the environment,in which nanocatalysts with high activity,selectivity and durability are of great importance.Intermetallic nanocrystals,featuring their ordered atomic arrangements and predictable electronic structures,have been recognized as a type of active and durable catalysts in energy-related applications.In this minireview,the very recent progress in the syntheses and electrocatalytic applications of noble metal-based intermetallic nanocrystals is summarized.Various synthetic strategies,including the conventional thermal annealing approach and its diverse modifications,as well as the wet-chemical synthesis,for the construction of binary,ternary and high-entropy intermetallic nanocrystals have been discussed with representative examples,highlighting their strengths and limitations.Then,their electrocatalytic applications toward oxygen reduction reaction,small molecule oxidation reactions,hydrogen evolution reaction,CO_(2)/CO reduction reactions,and nitrogen reduction reaction are discussed,with the emphasis on how the ordered intermetallic structures contribute to the enhanced performance.We conclude the minireview by addressing the current challenges and opportunities of intermetallic nanocrystals in terms of syntheses and electrocatalytic applications.